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Sample records for hydrocarbon synthesis preparation

  1. Theoretical and practical aspects of the synthesis of optimal systems of energy complex enterprises for preparation and processing of hydrocarbons

    Directory of Open Access Journals (Sweden)

    Dolotovskii Igor

    2017-01-01

    Full Text Available We have developed a technique for structural-parametric synthesis of optimal energy complex enterprises for preparation and processing of hydrocarbons, which employs the decomposition-search principle to create technological and constructive solutions; it is also based on mathematical apparatus of generalized quantitative quality evaluation. Developed the structure and composition of the equipment of the energy complex with the system of electric-, warmly- and water supply. The complex is integrated energy–technological systems, and provide maximum utilization of recycled energy resources and waste. The developed information-program software allows performing an evaluation of the a multi-criterion of the efficiency of systems of energy complex.

  2. SHS-produced intermetallides as catalysts for hydrocarbons synthesis from CO and H{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Eliseev, O.L.; Kazantsev, R.V.; Davydov, P.E.; Lapidus, A.L. [Russian Academy of Sciences, Moscow (Russian Federation). N.D. Zelinsky Institute of Organic Chemistry; Borshch, V.N.; Pugacheva, E.V. [Russian Academy of Sciences, Chernogolovka (Russian Federation). Inst. of Structural Macrokinetics and Materials Science

    2012-07-01

    Raney-type polymetallic alloys were prepared by Self-Propagating High-Temperature Synthesis followed by alkaline treating. Surface morphology and composition of were studied using XRD, BET, SEM and EMPA techniques. The samples were tested in Fischer-Tropsch synthesis demonstrated rather high activity and very high selectivity to heavy paraffins. High selectivity to C{sub 5+} hydrocarbons is attributed to high thermal conductivity of alloys which prevents hot spots formation and therefore suppresses formation of methane and light hydrocarbons. Selectivity can be further improved by adding some d-metals in catalyst composition. Promotion with La seems to be particularly suitable for lowering methane formation while doping with Ni enhances methane yield greatly. (orig.)

  3. SYNTHESIS OF PARTIAL-OXYGENATED HYDROCARBONS USING PHOTOCATALYSIS IN A LAMINAR FALLING FILM SLURRY REACTOR

    Science.gov (United States)

    The search for "Green" alternative processes for the oxidation of hydrocarbons selectively to partial oxygenates has been the subject of intense chemical research for many years. The USEPA is currently investigating an alternative synthesis pathway for the production of alcoho...

  4. Preparation and Aromatic Hydrocarbon Removal Performance of Potassium Ferrate

    Directory of Open Access Journals (Sweden)

    Wei Guan

    2014-01-01

    Full Text Available This experiment adopts the hypochlorite oxidation method to constantly synthesize potassium ferrate. Under the condition of micropolluted source water pH and on the basis of naphthalene, phenanthrene, and pyrene as research objects, the effects of different systems to remove aromatic hydrocarbons were studied. Various oxidation systems to remove phenanthrene intermediate are analyzed and the detailed mechanisms for removal of phenanthrene are discussed. The study found that the main intermediate of potassium ferrate system to transform phenanthrene is 9,10-phenanthraquinone and its area percentage reached 82.66%; that is, 9,10-phenanthraquinone is the key entity to remove phenanthrene.

  5. Ultradispersed Hydrocarbon Synthesis Catalyst from CO and H[2] Based on Electroexplosion of Iron Powder

    OpenAIRE

    Popok, E.V.; Levashova, A.I.; Chekantsev, N.V.; Kirgina, M.V.; Rafegerst, K. V.

    2014-01-01

    The structure and properties of disperse particles of electroexplosive iron-based powder are studied with a laser diffraction method, transmission electron microscopy analysis and X-ray photography. The catalytic activity of ultradispersed iron powders in the synthesis of hydrocarbons from CO and H[2] by Fischer - Tropsch method is measured by concentration of the paramagnetic particles with electron paramagnetic resonance. In the laboratory of catalytic plant, hydrocarbons are synthesized at...

  6. CO- and HCl-free synthesis of acid chlorides from unsaturated hydrocarbons via shuttle catalysis

    Science.gov (United States)

    Fang, Xianjie; Cacherat, Bastien; Morandi, Bill

    2017-11-01

    The synthesis of carboxylic acid derivatives from unsaturated hydrocarbons is an important process for the preparation of polymers, pharmaceuticals, cosmetics and agrochemicals. Despite its industrial relevance, the traditional Reppe-type carbonylation reaction using pressurized CO is of limited applicability to laboratory-scale synthesis because of: (1) the safety hazards associated with the use of CO, (2) the need for special equipment to handle pressurized gas, (3) the low reactivity of several relevant nucleophiles and (4) the necessity to employ different, often tailor-made, catalytic systems for each nucleophile. Herein we demonstrate that a shuttle-catalysis approach enables a CO- and HCl-free transfer process between an inexpensive reagent, butyryl chloride, and a wide range of unsaturated substrates to access the corresponding acid chlorides in good yields. This new transformation provides access to a broad range of carbonyl-containing products through the in situ transformation of the reactive acid chloride intermediate. In a broader context, this work demonstrates that isodesmic shuttle-catalysis reactions can unlock elusive catalytic reactions.

  7. Multi-metallic oxides as catalysts for light alcohols and hydrocarbons from synthesis gas

    Energy Technology Data Exchange (ETDEWEB)

    Perez, Miguel [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico); Diaz, L; Galindo, H de J; Dominguez, J. M; Salmon, Manuel [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    1999-08-01

    A series of Cu-Co-Cr oxides doped with alkaline metals (M), were prepared by the coprecipitation method with metal nitrates (Cu{sup I}I, CO{sup I}I, CR{sup I}II) and (M{sub 2})CO{sub 3} in aqueous solution. The calcined products were used as catalysts for the Fisher-Tropsch synthesis in a stainless-steel fixed bed microreactor. The material was characterized by x-ray diffraction, and the specific surface area, pore size and nitrogen adsorption-desorption properties were also determined. The alkaline metals favored the methanol synthesis and prevent the dehydration reactions whereas the hydrocarbon formation is independent to these metals. [Spanish] Una serie de oxidos Cu-Co-Cr soportados con metales alcalinos (M), fueron preparados por el metodo con nitratos metalicos (Cu{sup I}I, CO{sup I}I, CR{sup I}II) y (M{sub 2})CO{sub 3} en soluciones acuosas. Los productos calcinados fueron usados como catalizadores para la sintesis de Fisher-tropsch en la superficie fija de un microreactor de acero inoxidable. El material fue caracterizado por difraccion de rayos X y el area de superficie especifica, el tamano de poro y propiedades de absorcion-desorcion de nitrogeno fueron determinadas. Los metales alcalinos favorecieron la sintesis de metanol y previnieron las reacciones de deshidratacion, mientras que la formacion de hidrocarburos es independiente de estos metales.

  8. Combustion process for synthesis of carbon nanomaterials from liquid hydrocarbon

    Science.gov (United States)

    Diener, Michael D.; Alford, J. Michael; Nabity, James; Hitch, Bradley D.

    2007-01-02

    The present invention provides a combustion apparatus for the production of carbon nanomaterials including fullerenes and fullerenic soot. Most generally the combustion apparatus comprises one or more inlets for introducing an oxygen-containing gas and a hydrocarbon fuel gas in the combustion system such that a flame can be established from the mixed gases, a droplet delivery apparatus for introducing droplets of a liquid hydrocarbon feedstock into the flame, and a collector apparatus for collecting condensable products containing carbon nanomaterials that are generated in the combustion system. The combustion system optionally has a reaction zone downstream of the flame. If this reaction zone is present the hydrocarbon feedstock can be introduced into the flame, the reaction zone or both.

  9. Fischer-Tropsch Synthesis over Iron Manganese Catalysts: Effect of Preparation and Operating Conditions on Catalyst Performance

    OpenAIRE

    Mirzaei, Ali A.; Samaneh Vahid; Mostafa Feyzi

    2009-01-01

    Iron manganese oxides are prepared using a coprecipitation procedure and studied for the conversion of synthesis gas to light olefins and C5+ hydrocarbons. In particular, the effect of a range of preparation variables such as [Fe]/[Mn] molar ratios of the precipitation solution, pH of precipitation, temperature of precipitation, and precipitate aging times was investigated in detail. The results are interpreted in terms of the structure of ...

  10. Oil-shale gasification for obtaining of gas for synthesis of aliphatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Strizhakova, Yu. [Samara State Univ. (Russian Federation); Avakyan, T.; Lapidus, A.L. [I.M. Gubkin Russian State Univ. of Oil and Gas, Moscow (Russian Federation)

    2011-07-01

    Nowadays, the problem of qualified usage of solid fossil fuels as raw materials for obtaining of motor fuels and chemical products is becoming increasingly important. Gasification with further processing of gaseous products is a one of possible ways of their use. Production of synthesis gas with H{sub 2}/CO ratio equal 2 is possible by gasification of oil-shale. This gas is converted into the mixture of hydrocarbons over cobalt catalyst at temperature from 160 to 210 C at atmospheric pressure. The hydrocarbons can be used as motor, including diesel, or reactive fuel. (orig.)

  11. Synthesis and Characterization of Polycyclic Aromatic Hydrocarbons with Different Spatial Constructions Based on Hexaphenylbenzene Derivatives.

    Science.gov (United States)

    Chen, Hua; Zhu, Haoyun; Huang, Yuli; Yang, Junwei; Wang, Weizhi

    2017-12-05

    In recent years, low-bandgap polymers have attracted much attention in a wide range of fields. The synthesis of these compounds has been focused on three factors according to the Roncali bandgap theory: 1) the degree of bond-length alternation (E δr ), 2) the aromatic resonance energy of the cycle (E Res ), and 3) the substituted groups (E Sub ). Herein, we have designed and prepared low-bandgap polymers in a different way by using the factors E θ (the deviation from planarity of the polymer chain) and E Int (the interaction of the molecular chains in the solid state). Thus, three polycyclic aromatic hydrocarbons with different spatial constructions, based on hexaphenylbenzene derivatives, were prepared in this work: linear (P1-OX), V (P2-OX), and zigzag (P3-OX) types. These well-defined polymers exhibited interesting optical and electrochemistry behavior due to their different extents of planarity. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry gave the incremental orderly molecular weight distributions of P1, P2, and P3, the weight-average molecular weights (M‾w ) of which were 9000, 5500, and 69 000, respectively. Their lamellar layer structures and π-π intermolecular stacking were demonstrated by using two-dimensional grazing-incidence X-ray diffraction, which revealed the edge-on chain conformation. Finally, the materials were perfectly adapted to fabricate high-performance organic field-effect transistor devices, which revealed that these compounds could have great prospects as semiconductors. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Research Synthesis: Teacher Preparation for Rural Schools.

    Science.gov (United States)

    Meier, Ellen; Edington, Everett D.

    1983-01-01

    Reviews the literature of teacher preparation and inservice for rural areas, noting the dilemmas facing rural educators (multiple preparations, extracurricular duties, isolation, community problems), what colleges and universities can do (rural visibility, off-campus centers, curriculum expertise), and implications for colleges and universities…

  13. Role of cobalt catalyst porosity in the reaction of hydrocarbon synthesis from CO and H{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Eliseev, O.L.; Tsapkina, V.; Davydov, E. [Russian Academy of Sciences, Moscow (Russian Federation). N.D. Zelinsky Inst. of Organic Chemistry; Lapidus, A.L. [Russian Academy of Sciences, Moscow (Russian Federation). N.D. Zelinsky Inst. of Organic Chemistry; United Research and Development Centre, Moscow (Russian Federation)

    2010-12-30

    Effect of surface properties on catalyst performance is challenging problem for Fischer-Tropsch synthesis. We have studied a number of cobalt-alumina and cobalt-silica-alumina catalysts prepared by wet impregnation technique. Average pore diameter of supports varied from 6 to 100 nm. All the catalysts were activated uniformly in hydrogen and tested in FT synthesis. Non-linear dependence of cobalt crystallite size on average pore diameter of support have been found. For large pore aluminas with pore diameter 40 nm and more, cobalt crystallite size in activated Co-alumina catalysts reaches 14 nm and almost independent on pore diameter. Catalytic tests demonstrate that large-pore, low surface area supports are preferable in terms of activity. Calculated turnover rates reach 2.6-3.7 x 10{sup -3} s{sup -1} at 190 C for these catalysts. On the contrary, catalysts based on narrow-pore silica-aluminas display smaller turnover rate of about 0.4-0.8 x 10{sup -3} s{sup -1}. Thus, specific activity of small cobalt crystallites, 6 nm or less, was found to be lower than that of large particles. Molar selectivity to C{sub 5+} hydrocarbons reaches maximal values of 88-90% for supports with 7-12 nm average pore diameter. These samples provide lowest CH{sub 4} selectivity, 5-7 mol.%. (orig.)

  14. Synthesis and characterization of zinc oxide thin films prepared by ...

    African Journals Online (AJOL)

    Synthesis and characterization of zinc oxide thin films prepared by chemical the bath technique. ... The band gap energy of the samples deduced from the fundamental absorption edge gave the values of 1.60 – 2.80 eV for the direct ... Keywords: Chemical bath technique, zinc oxide thin films, x-ray, photovoltaic cells ...

  15. Determination of Polycyclic Aromatic Hydrocarbons in Water Using Nanoporous Material Prepared from Waste Avian Egg Shell

    National Research Council Canada - National Science Library

    Nuhu, Abdulmumin A; Basheer, Chanbasha; Shaikh, Amjad Ashfaque; Al-Arfaj, Abdul Rahman

    2012-01-01

      For the first time a biocompatible calcium carbonate vateritic polymorph was recrystallized from eggshell waste and its application for the extraction of polycyclic aromatic hydrocarbons in water...

  16. Synthesis and Characterization of Quaternary Metal Chalcogenide Aerogels for Gas Separation and Volatile Hydrocarbon Adsorption

    KAUST Repository

    Edhaim, Fatimah A.

    2017-11-01

    In this dissertation, the metathesis route of metal chalcogenide aerogel synthesis was expanded by conducting systematic studies between polysulfide building blocks and the 1st-row transition metal linkers. Resulting materials were screened as sorbents for selective gas separation and volatile organic compounds adsorption. They showed preferential adsorption of polarizable gases (CO2) and organic compounds (toluene). Ion exchange and heavy metal remediation properties have also been demonstrated. The effect of the presence of different counter-ion within chalcogel frameworks on the adsorption capacity of the chalcogels was studied on AFe3Zn3S17 (A= K, Na, and Rb) chalcogels. The highest adsorption capacity toward hydrocarbons and gases was observed on Rb based chalcogels. Adopting a new building block [BiTe3]3- with the 1st-row transition metal ions results in the formation of three high BET surface area chalcogels, KCrBiTe3, KZnBiTe3, and KFeBiTe3. The resulting chalcogels showed preferential adsorption of toluene vapor, and remarkable selectivity of CO2, indicating the potential future use of chalcogels in adsorption-based gas or hydrocarbon separation processes. The synthesis and characterization of the rare earth chalcogels NaYSnS4, NaGdSnS4, and NaTbSnS4 are also reported. Rare earth metal ions react with the thiostannate clusters in formamide solution forming extended polymeric networks by gelation. Obtained chalcogels have high BET surface areas, and showed notable adsorption capacity toward CO2 and toluene vapor. These chalcogels have also been engaged in the absorption of different organic molecules. The results reveal the ability of the chalcogels to distinguish among organic molecules on their electronic structures; hence, they could be used as sensors. Furthermore, the synthesis of metal chalcogenide aerogels Co0.5Sb0.33MoS4 and Co0.5Y0.33MoS4 by the sol-gel method is reported. In this system, the building blocks [MoS4]2- chelated with Co2+ and (Sb3

  17. Preparation of IrO2-Ta2O5|Ti electrodes by immersion, painting and electrophoretic deposition for the electrochemical removal of hydrocarbons from water.

    Science.gov (United States)

    Herrada, Rosa Alhelí; Medel, Alejandro; Manríquez, Federico; Sirés, Ignasi; Bustos, Erika

    2016-12-05

    After intense years of great development, the electrochemical technologies have become very suitable alternatives in niche markets like industrial wastewater reclamation and soil remediation. A key role to achieve a high efficiency in such treatments is played by the characteristics of the coating of the electrodes employed. This paper compares three techniques, namely immersion, painting and electrophoresis, for the preparation of IrO2-Ta2O5ǀTi, so-called dimensionally stable anodes (DSA(®)). The quality of the coatings has been investigated by means of surface and electrochemical analysis. Their ability to generate hydroxyl radicals and degrade aqueous solutions of hydrocarbons like phenanthrene, naphthalene and fluoranthene has been thoroughly assessed. Among the synthesis techniques, electrophoretic deposition yielded the best results, with DSA(®) electrodes exhibiting a homogeneous surface coverage that led to a good distribution of active sites, thus producing hydroxyl radicals that were able to accelerate the degradation of hydrocarbons. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Novel synthesis strategy for the preparation of individual phytosterol oxides.

    Science.gov (United States)

    Gao, Junlan; Yue, Qiulin; Ji, Yishun; Cheng, Beijiu; Zhang, Xin

    2013-01-30

    Sterols (cholesterol and phytosterols) are important structural components of cell membranes and major constituents of lipid metabolism. Research on their oxides, such as the factors affecting oxidation, oxides' structures, and qualitative and quantitative analysis, aroused more attention in this decade. However, the biological roles of individual phytosterol oxides are still unclear because no commercial individual phytosterol oxide standards are available. Different from the traditional chemical synthesis, in the present study, chemical synthesis from a starting phytosterol mixture followed with a semipreparative HPLC separation produced individual oxides. TLC and analytical HPLC were used here to not only monitor the reaction process but also specifically analyze the synthetic intermediates and oxides. The chromatographic results exhibited strict rules and similar characteristics. Finally, for the first time, four individual phytosterol oxides were successfully separated and collected by a semipreparative HPLC system, thus providing a novel strategy for the preparation of individual phytosterol oxides.

  19. Solvothermal synthesis: a new route for preparing nitrides

    CERN Document Server

    Demazeau, G; Denis, A; Largeteau, A

    2002-01-01

    Solvothermal synthesis appears to be an interesting route for preparing nitrides such as gallium nitride and aluminium nitride, using ammonia as solvent. A nitriding additive is used to perform the reaction and, in the case of gallium nitride, is encapsulated by melt gallium. The syntheses are performed in the temperature range 400-800 deg. C and in the pressure range 100-200 MPa. The synthesized powders are characterized by x-ray diffraction and scanning electron microscopy. Finely divided gallium nitride GaN and aluminium nitride AlN, both with wurtzite-type structure, can be obtained by this route.

  20. Study of barium bismuth titanate prepared by mechanochemical synthesis

    Directory of Open Access Journals (Sweden)

    Lazarević Z.Ž.

    2009-01-01

    Full Text Available Barium-bismuth titanate, BaBi4Ti4O15 (BBT, a member of Aurivillius bismuth-based layer-structure perovskites, was prepared from stoichiometric amounts of barium titanate and bismuth titanate obtained via mechanochemical synthesis. Mechanochemical synthesis was performed in air atmosphere in a planetary ball mill. The reaction mechanism of BaBi4Ti4O15 and the preparation and characteristics of BBT ceramic powders were studied using XRD, Raman spectroscopy, particle analysis and SEM. The Bi-layered perovskite structure of BaBi4Ti4O15 ceramic forms at 1100 °C for 4 h without a pre-calcination step. The microstructure of BaBi4Ti4O15 exhibits plate-like grains typical for the Bi-layered structured material and spherical and polygonal grains. The Ba2+ addition leads to changes in the microstructure development, particularly in the change of the average grain size.

  1. Synthesis of condensed phases containing polycyclic aromatic hydrocarbons fullerenes and nanotubes

    Science.gov (United States)

    Reilly, Peter T. A.

    2004-10-19

    The invention relates to methods for producing polycyclic aromatic hydrocarbons, fullerenes, and nanotubes, comprising: a. heating at least one carbon-containing material to form a condensed phase comprising at least one polycyclic aromatic hydrocarbon; b. collecting at least some of the condensed phase; c. reacting the condensed phase to form fullerenes and/or nanotubes.

  2. Benzo[a]pyrene/aryl hydrocarbon receptor signaling inhibits osteoblastic differentiation and collagen synthesis of human periodontal ligament cells.

    Science.gov (United States)

    Monnouchi, S; Maeda, H; Yuda, A; Serita, S; Wada, N; Tomokiyo, A; Akamine, A

    2016-12-01

    Cigarette smoking has detrimental effects on periodontal tissue, and is known to be a risk factor for periodontal disease, including the loss of alveolar bone and ligament tissue. However, the direct effects of cigarette smoking on periodontal tissue remain unclear. Recently, we demonstrated that benzo[a]pyrene (BaP), which is a prototypic member of polycyclic aryl hydrocarbons and forms part of the content of cigarettes, attenuated the expression of extracellular matrix remodeling-related genes in human periodontal ligament (PDL) cells (HPDLCs). Thus, we aimed to examine the effects of BaP on the osteoblastic differentiation and collagen synthesis of HPDLCs. HPDLCs were obtained from healthy molars of three patients, and quantitative reverse transcription-polymerase chain reaction were performed for gene expression analyses of cytochrome P450 1A1 and 1B1, alkaline phosphatase, bone sialoprotein and aryl hydrocarbon receptor (AhR), a receptor for polycyclic aryl hydrocarbons. We have also analyzed the role of the AhR, using 2-methyl-2H-pyrazole-3-carboxylic acid (2-methyl-4-o-tolylazo-phenyl)-amide (CH-223191), which is an AhR antagonist. The treatment of HPDLCs with BaP reduced mRNA expression of osteogenic genes, alkaline phosphatase activity, mineralization and collagen synthesis. The treatment with CH-223191 subsequently restored the observed suppressive effects of BaP on HPDLCs. The present results suggest that BaP exerts inhibitory effects on the maintenance of homeostasis in HPDL tissue, such as osteoblastic differentiation and collagen synthesis of HPDLCs, and that this signaling pathway could be suppressed by preventing the transactivity of AhR. Future studies may unveil a role for the inhibition of AhR as a promising therapeutic agent for periodontal disease caused by cigarette smoking. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. A new hydrocarbon material based on seabuckthorn ( Hippophae rhamnoides) sawdust: A structural promoter of cobalt catalyst for Fischer-Tropsch synthesis

    Science.gov (United States)

    Pankina, G. V.; Chernavskii, P. A.; Lunin, V. V.

    2016-09-01

    Aspects of the physicochemical properties of a hydrocarbon material based on seabuckthorn ( Hippophae rhamnoides) sawdust are studied. The use of a hydrocarbon material based on sea buckthorn sawdust as a structural promoter of Co/CHip cobalt catalyst in the reaction of CO hydrogenation is shown to require an additional cycling stage in the mode of reduction and oxidation. The resulting mean size of the Co particles is found to be 18-19 nm and is considered acceptable for the synthesis of C5+ liquid hydrocarbons.

  4. Short Synthesis of Sulfur Analogues of Polyaromatic Hydrocarbons through Three Palladium-Catalyzed C-H Bond Arylations.

    Science.gov (United States)

    Hagui, Wided; Besbes, Néji; Srasra, Ezzeddine; Roisnel, Thierry; Soulé, Jean-François; Doucet, Henri

    2016-09-02

    An expeditious synthesis of a wide range of phenanthro[9,10-b]thiophene derivatives, which are a class of polyaromatic hydrocarbon (PAH) containing a sulfur atom, is reported. The synthetic scheme involves only two operations from commercially available thiophenes, 2-bromobenzenesulfonyl chlorides and aryl bromides. In the first step, palladium-catalyzed desulfitative arylation using 2-bromobenzenesulfonyl chlorides allows the synthesis of thiophene derivatives, which are substituted at the C4 position by an aryl group containing an ortho-bromo substituent. Then, a palladium-catalyzed one-pot cascade intermolecular C5-arylation of thiophene using aryl bromides followed by intramolecular arylation led to the corresponding phenanthro[9,10-b]thiophenes in a single operation. In addition, PAHs containing two or three sulfur atoms, as well as both sulfur and nitrogen atoms, were also designed by this strategy.

  5. Synthesis and characterization of hydrophobic zeolite for the treatment of hydrocarbon contaminated ground water.

    Science.gov (United States)

    Northcott, Kathy A; Bacus, Joannelle; Taya, Naoyuki; Komatsu, Yu; Perera, Jilska M; Stevens, Geoffrey W

    2010-11-15

    Hydrophobic zeolite was synthesized, modified and characterized for its suitability as a permeable reactive barrier (PRB) material for treatment of hydrocarbons in groundwater. Batch sorption tests were performed along with a number of standard characterization techniques. High and low ionic strength and pH tests were also conducted to determine their impact on hydrocarbon uptake. Further ion exchange tests were conducted to determine the potential for the zeolite to act as both a hydrocarbon capture material and nutrient a delivery system for bioremediation. The zeolite was coated with octadecyltrichlorosilane (C18) to change its surface properties. The results of the surface characterization tests showed that the underlying zeolite structure was largely unaffected by the coating. TGA measurements showed a reactive carbon content of 1-2%. Hydrocarbon (o-xylene and naphthalene) sorption isotherms results compared well with the behaviour of similar materials investigated by other researchers. Ionic strength and pH had little effect on hydrocarbon sorption and the treated zeolite had an ion exchange capacity of 0.3 mequiv./g, indicating it could be utilised as a nutrient source in PRBs. Recycle tests indicated that the zeolite could be used cleaned and reused at least three times without significant reduction in treatment effectiveness. Copyright © 2010 Elsevier B.V. All rights reserved.

  6. Synthesis and characterization of zeolites prepared from industrial fly ash.

    Science.gov (United States)

    Franus, Wojciech; Wdowin, Magdalena; Franus, Małgorzata

    2014-09-01

    In this paper, we present the possibility of using fly ash to produce synthetic zeolites. The synthesis class F fly ash from the Stalowa Wola SA heat and power plant was subjected to 24 h hydrothermal reaction with sodium hydroxide. Depending on the reaction conditions, three types of synthetic zeolites were formed: Na-X (20 g fly ash, 0.5 dm(3) of 3 mol · dm(-3) NaOH, 75 °C), Na-P1 (20 g fly ash, 0.5 dm(3) of 3 mol · dm(-3) NaOH, 95 °C), and sodalite (20 g fly ash, 0.8 dm(3) of 5 mol · dm(-3) NaOH + 0.4 dm(3) of 3 mol · dm(-3) NaCl, 95 °C). As synthesized materials were characterized to obtain mineral composition (X-ray diffractometry, Scanning electron microscopy-energy dispersive spectrometry), adsorption properties (Brunauer-Emmett-Teller surface area, N2 isotherm adsorption/desorption), and ion exchange capacity. The most effective reaction for zeolite preparation was when sodalite was formed and the quantitative content of zeolite from X-ray diffractometry was 90 wt%, compared with 70 wt% for the Na-X and 75 wt% for the Na-P1. Residues from each synthesis reaction were the following: mullite, quartz, and the remains of amorphous aluminosilicate glass. The best zeolitic material as characterized by highest specific surface area was Na-X at almost 166 m(2) · g(-1), while for the Na-P1 and sodalite it was 71 and 33 m(2) · g(-1), respectively. The ion exchange capacity decreased in the following order: Na-X at 1.8 meq · g(-1), Na-P1 at 0.72 meq · g(-1), and sodalite at 0.56 meq · g(-1). The resulting zeolites are competitive for commercially available materials and are used as ion exchangers in industrial wastewater and soil decontamination.

  7. Synthesis of carbon nanotube using camphor with SS 316 as catalytic substrate via oxidative heat treatment preparation method

    Science.gov (United States)

    Wulan, Praswasti Pembangun Dyah Kencana; Angelina, Dian

    2017-11-01

    Carbon nanotube (CNT) is a material that now often become the topic in nanotechnology research. CNT is widely used in the electronics industry especially for TV and computer flat panel displays, devices, automotives for car components, and batteries. Also for defense industries as well as other industries such as sports equipment. Camphor (C10H16O), a botanical hydrocarbon, can be used as a renewable and low cost carbon source for CNT synthesis. Synthesis was performed with stainless steel-316 (SS 316) as substrate, argon as carrier gas, and hydrogen as co-reactant. Preparation of the SS 316 was through a pretreatment by oxidative heat treatment method at a temperature of 850oC for 30 minutes, to remove the layer of chrome and make a rough surface as a growth media for CNT. The operating temperature of the synthesis used was 800oC with a reaction time of 60 minutes. Reactor, which made from stainless steel 316 (SS 316), was used for synthesis CNTs with maximum camphor mass of 20 grams. This research was conducted by varying the number of camphor mass by 5, 7, 10, 12, and 15 grams. The results showed that camphor decomposed into three compounds which are 40% benzene, 8% toluene, and 52% xylene. CNT grows on the surface of the SS 316 plate for each variation. CNTs have grown by follow tips growth model with deformations like buckling growth model and continuous growth model were also founded. The results of XRD showed that CNT were found in every camphor mass variation with high intensity at 2θ angle of 26° and 43°. The best quality and yield of CNT was obtained at camphor mass of 15 grams with carbon percentage of 87,1% and diameter 33 - 44 nm.

  8. Isolation, Determination of Absolute Stereochemistry, and Asymmetric Synthesis of Insect Methyl-Branched Hydrocarbons

    OpenAIRE

    Bello, Jan Edgar

    2014-01-01

    Methyl-branched hydrocarbons (MBCHs) are ubiquitous components of insect cuticular lipids. Several have been shown to function as contact pheromones, and it is likely that many more remain to be discovered. The majority of insect produced MBCHs are chiral, but there have been no studies to determine whether they are biosynthesized enantiospecifically. In fact, there have been only a handful of studies on the effects of chirality on the biological activities of MBCH contact pheromones. This i...

  9. Disordered Manganese Oxide Nano-powder Prepared by Low-temperature Synthesis Followed by Acid Treatment

    OpenAIRE

    Koyanaka, Hideki; Hata, Toshihiro; IMAMURA, Yuji

    2005-01-01

    Disordered manganese oxide, prepared by low-temperature synthesis followed by acid treatment is introduced. Aggregated nano-powder of disordered manganese oxide was obtained in this method. The disordered manganese oxide is suitable starting material for the preparation of efficient adsorbents for the removal of harmful metals from the environment.

  10. Synthesis of a labelled terpene synthon, useful in the preparation of metabolites of [Delta][sup 1]-tetrahydrocannabinol

    Energy Technology Data Exchange (ETDEWEB)

    Szirmai, M. (Uppsala Univ. (Sweden)); Halldin, M.M.; Ohlsson, A. (Karolinska Inst., Stockholm (Sweden))

    1992-02-01

    The synthesis of an isotopically labelled terpene synthon (4) is described. The usefulness of this terpene synthon in the synthesis of [delta][sup 1]-THC metabolites is shown by preparation of ([+-])-[[sup 2]H[sub 10

  11. Synthesis of Hydrocarbons from H2-Deficient Syngas in Fischer-Tropsch Synthesis over Co-Based Catalyst Coupled with Fe-Based Catalyst as Water-Gas Shift Reaction

    National Research Council Canada - National Science Library

    Ma, Ting; Imai, Hiroyuki; Shige, Tomohiro; Sugio, Taisuke; Li, Xiaohong

    2015-01-01

    ... by the catalyst particles. The metal-added Fe-based catalysts were employed together with Co-loaded beta zeolite for the synthesis of hydrocarbons from syngas with a lower H2/CO ratio of 1 than the stoichiometric H2/CO ratio...

  12. Synthesis of extended polycyclic aromatic hydrocarbons by oxidative tandem spirocyclization and 1,2-aryl migration

    Science.gov (United States)

    Zhang, Xuan; Xu, Zhanqiang; Si, Weili; Oniwa, Kazuaki; Bao, Ming; Yamamoto, Yoshinori; Jin, Tienan

    2017-04-01

    The extended polycyclic aromatic hydrocarbons (PAHs) have received significant interdisciplinary attention due to their semiconducting applications in diverse organic electronics as well as intriguing structural interests of well-defined graphene segments. Herein, a highly efficient oxidative spirocyclization and 1,2-aryl migration tandem synthetic method for the construction of extended polyaromatic hydrocarbons (PAHs) has been developed. The CuCl-catalyst/PhCO3 tBu or DDQ oxidation system in the presence of trifluoroacetic acid enables the selective single-electron oxidation to take place preferentially at the more electron-rich alkene moiety of o-biphenylyl-substituted methylenefluorenes, giving rise to the subsequent tandem process. A variety of structurally diverse extended PAHs including functionalized dibenzo[g,p]chrysenes, benzo[f]naphtho[1,2-s]picene, hexabenzo[a,c,fg,j,l,op]tetracene, tetrabenzo[a,c,f,m]phenanthro[9,10-k]tetraphene, tetrabenzo[a,c,f,k]phenanthro[9,10-m]tetraphene, tetrabenzo[a,c,f,o]phenanthro[9,10-m]picene and S-type helicene have been readily synthesized.

  13. Cold- Process Synthesis and Properties of Soaps Prepared from ...

    African Journals Online (AJOL)

    acer

    mgKOH / g for cassia siamea( Hassan at et al, 2005) but higher than (1.84 ) reported for sesame seed oil. ( Almustapha et al, 1995 ) which are used in soap making. Table 2: Foam height of soaps prepared. Prepared Soaps. Height of foam.

  14. Recent advances in solid-phase peptide synthesis and preparation of antibodies to synthetic peptides.

    Science.gov (United States)

    Plaue, S; Muller, S; Briand, J P; Van Regenmortel, M H

    1990-07-01

    Peptides prepared by the solid-phase peptide synthesis (SPPS) approach are used increasingly in biological research, for instance to elicit anti-peptide antibodies that will recognize the intact, cognate protein. Recent advances in SPPS are reviewed, including the use of new coupling reagents, new methods for evaluating peptide purity and new techniques of automated and multiple peptide synthesis. Methods for enhancing peptide immunogenicity are discussed such as the use of adjuvants and liposomes, and of synthetic branched polypeptides as carriers.

  15. Growth and biosurfactant synthesis by Nigerian hydrocarbon-degrading estuarine bacteria

    Directory of Open Access Journals (Sweden)

    Sunday A Adebusoye

    2008-12-01

    Full Text Available The ability of microorganisms to degrade petroleum hydrocarbons is important for finding an environmentally-friendly method to restoring contaminated environmental matrices. Screening of hydrocarbon-utilizing and biosurfactant-producing abilities of organisms from an estuarine ecosystem in Nigeria, Africa, resulted in the isolation of five microbial strains identified as Corynebacterium sp. DDv1, Flavobacterium sp. DDv2, Micrococcus roseus DDv3, Pseudomonas aeruginosa DDv4 and Saccharomyces cerevisae DDv5. These isolates grew readily on several hydrocarbons including hexadecane, dodecane, crude oil and petroleum fractions. Axenic cultures of the organisms utilized diesel oil (1.0 % v/v with generation times that ranged significantly (t-test, P La capacidad de los microorganismos para degradar hidrocarburos del petróleo es de gran importancia para hallar un método aceptable y ambientalmente amigable para la restauración de terrenos ambientalmente contaminados. Al investigar las capacidades de los organismos de un ecosistema de estuario que utilizan hidrocarburos y producen biosurfactantes, se produjo como resultado el aislamiento de cinco cepas microbianas identificadas como Corynebacterium sp. DDv1, Flavobacterium sp. DDv2, Micrococcus roseus DDv3, Pseudomonas aeruginosa y DDv4 Saccharomyces cerevisiae DDv5. Estas cepas crecieron fácilmente en varios hidrocarburos incluyendo hexadecanos, dodecanos, petróleo crudo y fracciones de petróleo. Los cultivos axénicos de organismos utilizaron diesel (1.0% v/v con períodos por generación con ámbitos significativos (t-test, P <0.05 de entre 3.25 y 3.88 días, con la consiguiente producción de bio-surfactantes. La cinética del crecimiento indica que la síntesis de bio-surfactante se produjo principalmente durante la fase de crecimiento exponencial, lo que sugiere que las moléculas bioactivas son metabolitos primarios. Las cepas DDv1 y DDv4 fueron evidentemente las más metab

  16. Low temperature formation of naphthalene and its role in the synthesis of PAHs (Polycyclic Aromatic Hydrocarbons) in the interstellar medium

    Science.gov (United States)

    Zhang, Fangtong; Kim, Y. Seol; Kaiser, Ralf I.; Landera, Alexander; Kislov, Vadim V.; Mebel, Alexander M.; Tielens, A. G. G. M.

    2012-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are regarded as key molecules in the astrochemical evolution of the interstellar medium, but the formation mechanism of even their simplest prototype—naphthalene (C10H8)—has remained an open question. Here, we show in a combined crossed beam and theoretical study that naphthalene can be formed in the gas phase via a barrierless and exoergic reaction between the phenyl radical (C6H5) and vinylacetylene (CH2 = CH-C ≡ CH) involving a van-der-Waals complex and submerged barrier in the entrance channel. Our finding challenges conventional wisdom that PAH-formation only occurs at high temperatures such as in combustion systems and implies that low temperature chemistry can initiate the synthesis of the very first PAH in the interstellar medium. In cold molecular clouds, barrierless phenyl-type radical reactions could propagate the vinylacetylene-mediated formation of PAHs leading to more complex structures like phenanthrene and anthracene at temperatures down to 10 K. PMID:22198769

  17. Synthesis of Biscardanol as Key Intermediary in Preparation of Bistioxanthones

    Directory of Open Access Journals (Sweden)

    Glaucia Almeida Nunes

    2012-06-01

    Full Text Available The cashew nut shell liquid (CNSL is an important source of phenolic compounds such as anacardic acids, cardols and cardanols. These compounds present many biological activities. The components of CNSL were isolated and purified by column chromatography. Cardanol was employed as starting material for a methathesis reaction making use of Grubbs 1st generation catalyst, under nitrogen atmosphere, in dichloromethane, heating at 50 oC and, magnetic stirring during 98 h. The product biscardanol is a key-intermediate for the synthesis of new bis thioxanthones.

  18. Synthesis and characterization of zeolites prepared from industrial fly ash

    OpenAIRE

    Franus, Wojciech; Wdowin, Magdalena; Franus, Małgorzata

    2014-01-01

    In this paper, we present the possibility of using fly ash to produce synthetic zeolites. The synthesis class F fly ash from the Stalowa Wola SA heat and power plant was subjected to 24 h hydrothermal reaction with sodium hydroxide. Depending on the reaction conditions, three types of synthetic zeolites were formed: Na-X (20 g fly ash, 0.5 dm3 of 3 mol · dm−3 NaOH, 75 °C), Na-P1 (20 g fly ash, 0.5 dm3 of 3 mol · dm−3 NaOH, 95 °C), and sodalite (20 g fly ash, 0.8 dm3 of 5 mol · dm−3 NaOH + 0.4...

  19. Parallel fluorescent probe synthesis based on the large-scale preparation of BODIPY FL propionic acid.

    Science.gov (United States)

    Katoh, Taisuke; Yoshikawa, Masato; Yamamoto, Takeshi; Arai, Ryosuke; Nii, Noriyuki; Tomata, Yoshihide; Suzuki, Shinkichi; Koyama, Ryoukichi; Negoro, Nobuyuki; Yogo, Takatoshi

    2017-03-01

    We describe a methodology for quick development of fluorescent probes with the desired potency for the target of interest by using a method of parallel synthesis, termed as Parallel Fluorescent Probe Synthesis (Parallel-FPS). BODIPY FL propionic acid 1 is a widely used fluorophore, but it is difficult to prepare a large amount of 1, which hinders its use in parallel synthesis. Optimization of a synthetic scheme enabled us to obtain 50g of 1 in one batch. With this large quantity of 1 in hand, we performed Parallel-FPS of BODIPY FL-labeled ligands for estrogen related receptor-α (ERRα). An initial trial of the parallel synthesis with various linkers provided a potent ligand for ERRα (Reporter IC 50 =80nM), demonstrating the usefulness of Parallel-FPS. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Multiwalled Carbon Nanotube Synthesis Using Arc Discharge with Hydrocarbon as Feedstock

    Directory of Open Access Journals (Sweden)

    K. T. Chaudhary

    2013-01-01

    Full Text Available Synthesis of multiwalled carbon nanotube (MWCNT by arc discharge process is investigated with methane (CH4 as background and feedstock gas. The arc discharge is carried out between two graphite electrodes for ambient pressures 100, 300, and 500 torr and arc currents 50, 70, and 90 A. Plasma kinetics such as the density and temperature for arc discharge carbon plasma is determined to find out the contribution of physical parameters as arc current and ambient pressure on the plasma dynamics and growth of MWCNT. With increase in applied arc current and ambient pressure, an increase in plasma temperature and density is observed. The synthesized samples of MWCNT at different experimental conditions are characterized by transmission electron microscopy, scanning electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. A decrease in the diameter and improvement in structure quality and growth of MWCNT are observed with increase in CH4 ambient pressure and arc current. For CH4 ambient pressure 500 torr and arc current 90 A, the well-aligned and straight MWCNT along with graphene stakes are detected.

  1. Preparation of polyoxometalates in ionic liquids by ionothermal synthesis.

    Science.gov (United States)

    Lin, Shiwei; Liu, Wenli; Li, Yangguang; Wu, Qiong; Wang, Enbo; Zhang, Zhiming

    2010-02-21

    Ionothermal synthesis was applied to the formation of polyoxometalates (POMs) and two new compounds [EMIM](8)Na(9)[WFe(9)(micro(3)-O)(3)(micro(2)-OH)(6)O(4)H(2)O(SiW(9)O(34))(3)].7H(2)O (, [EMIM](8)Na(9)[].7H(2)O, EMIM = 1-ethyl-3-methylimidazolium) and [EMIM](4)[SiMo(12)O(40)].12H(2)O (), have been successfully produced in the ionic liquid (IL) [EMIM](4)Br. They were characterized by single-crystal X-ray diffraction, elemental analysis, UV-vis, IR and TG analysis. Furthermore, the magnetic properties of and the electrochemical properties of were studied. is a high-nuclear transition metal substituted polyoxometalate (TMSP) and the unprecedented polyoxoanion of is composed of three [alpha-SiW(9)O(34)](10-) Keggin moieties connected by a {WFe(9)} cluster core. is a heteropolyoxometalate with the polyoxoanion of alpha-Keggin type.

  2. Morphology control of brushite prepared by aqueous solution synthesis

    Directory of Open Access Journals (Sweden)

    T. Toshima

    2014-03-01

    Full Text Available Dicalcium phosphate dihydrate (DCPD, CaHPO4·2H2O, also known as brushite, is one of the important bioceramics due to not only diseases factors such as kidney stone and plaque formation but also purpose as fluoride insolubilization material. It is used medicinally to supply calcium, and is of interest for its unique properties in biological and pathological mineralization. It is important to control the crystal morphology of brushite since its chemical reactivity depends strongly on its surface properties; thus, its morphology is a key issue for its applications as a functional material or precursor for other bioceramics. Here, we report the effects of the initial pH and the Ca and phosphate ion concentrations on the morphology of DCPD particles during aqueous solution synthesis. Crystal morphologies were analyzed by scanning electron microscopy and X-ray diffraction. The morphology phase diagram of DCPD crystallization revealed that increasing the initial pH and/or ion concentration transformed DCPD morphology from petal-like into plate-like structures.

  3. Method of preparing and utilizing a catalyst system for an oxidation process on a gaseous hydrocarbon stream

    Science.gov (United States)

    Berry, David A; Shekhawat, Dushyant; Smith, Mark; Haynes, Daniel

    2013-07-16

    The disclosure relates to a method of utilizing a catalyst system for an oxidation process on a gaseous hydrocarbon stream with a mitigation of carbon accumulation. The system is comprised of a catalytically active phase deposited onto an oxygen conducting phase, with or without supplemental support. The catalytically active phase has a specified crystal structure where at least one catalytically active metal is a cation within the crystal structure and coordinated with oxygen atoms within the crystal structure. The catalyst system employs an optimum coverage ratio for a given set of oxidation conditions, based on a specified hydrocarbon conversion and a carbon deposition limit. Specific embodiments of the catalyst system are disclosed.

  4. Difluorenyl carbo-Benzenes: Synthesis, Electronic Structure, and Two-Photon Absorption Properties of Hydrocarbon Quadrupolar Chromophores.

    Science.gov (United States)

    Baglai, Iaroslav; de Anda-Villa, Manuel; Barba-Barba, Rodrigo M; Poidevin, Corentin; Ramos-Ortíz, Gabriel; Maraval, Valérie; Lepetit, Christine; Saffon-Merceron, Nathalie; Maldonado, José-Luis; Chauvin, Remi

    2015-09-28

    The synthesis, crystal and electronic structures, and one- and two-photon absorption properties of two quadrupolar fluorenyl-substituted tetraphenyl carbo-benzenes are described. These all-hydrocarbon chromophores, differing in the nature of the linkers between the fluorenyl substituents and the carbo-benzene core (C-C bonds for 3 a, C-C=C-C expanders for 3 b), exhibit quasi-superimposable one-photon absorption (1PA) spectra but different two-photon absorption (2PA) cross-sections σ2PA. Z-scan measurements (under NIR femtosecond excitation) indeed showed that the C≡C expansion results in an approximately twofold increase in the σ2PA value, from 336 to 656 GM (1 GM = 10(-50) cm(4) s molecule(-1) photon(-1)) at λ = 800 nm. The first excited states of Au and Ag symmetry accounting for 1PA and 2PA, respectively, were calculated at the TDDFT level of theory and used for sum-over-state estimations of σ2PA(λi), in which λi = 2 hc/Ei, h is Planck's constant, c is the speed of light, and Ei is the energy of the 2PA-allowed transition. The calculated σ2PA values of 227 GM at 687 nm for 3 a and 349 GM at 708 nm for 3 b are in agreement with the Z-scan results. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Application of pyrolitic method of synthesis for preparation of calcium bismuthate based photocatalyst

    Science.gov (United States)

    Shtarev, Dmitry S.; Makarevich, Konstantin S.; Shtareva, Anna V.; Blokh, Artem I.; Syuy, Alexander V.

    2016-11-01

    The study describes use of pyrolytic synthesis method for preparation of visible light calcium bismuthate based photocatalyst. The advantage of the proposed method is that it allows obtaining single-phase, homogeneous samples with various types of crystal lattice and controlled defects. It is shown that it is possible to obtain crystalline calcium bismuthate with the same stoichiometry in the entire region of existence of the solid solution. Synthesized samples of calcium bismuthate have been characterized using the scanning electron microscopy and X-ray analysis. It was found that the scope and conditions of synthesis affect the degree of imperfection of both anionic and cationic sublattice of calcium bismuthate.

  6. Facile Synthesis of Highly Active and Robust Ni-Mo Bimetallic Electrocatalyst for Hydrocarbon Oxidation in Solid Oxide Fuel Cells

    NARCIS (Netherlands)

    Hua, B.; Li, M.; Zhang, Y.-Q.; Chen, J.; Sun, Y.-F.; Yan, N.; Li, J.; Luo, J.L.

    2016-01-01

    We report a novel Ni–Mo bimetallic alloy decorated with multimicrocrystals as an efficient anode catalyst for hydrocarbon-fueled solid oxide fuel cells (SOFCs). We show that these Ni–Mo bimetallic alloys are highly active, thermally stable, and sulfur/coke tolerant electrocatalysts for hydrocarbon

  7. Bi-reforming of methane from any source with steam and carbon dioxide exclusively to metgas (CO-2H2) for methanol and hydrocarbon synthesis.

    Science.gov (United States)

    Olah, George A; Goeppert, Alain; Czaun, Miklos; Prakash, G K Surya

    2013-01-16

    A catalyst based on nickel oxide on magnesium oxide (NiO/MgO) thermally activated under hydrogen is effective for the bi-reforming with steam and CO(2) (combined steam and dry reforming) of methane as well as natural gas in a tubular flow reactor at elevated pressures (5-30 atm) and temperatures (800-950 °C). By adjusting the CO(2)-to-steam ratio in the gas feed, the H(2)/CO ratio in the produced syn-gas could be easily adjusted in a single step to the desired value of 2 for methanol and hydrocarbon synthesis.

  8. Preparation of molybdenum borides by combustion synthesis involving solid-phase displacement reactions

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, C.L. [Department of Mechanical and Automation Engineering, Da-Yeh University, 112 Shan-Jiau Rd., Da-Tsuen, Changhua 51505, Taiwan (China)], E-mail: clyeh@mail.dyu.edu.tw; Hsu, W.S. [Department of Mechanical and Automation Engineering, Da-Yeh University, 112 Shan-Jiau Rd., Da-Tsuen, Changhua 51505, Taiwan (China)

    2008-06-12

    Preparation of molybdenum borides of five different phases in the Mo-B binary system (including Mo{sub 2}B, MoB, MoB{sub 2}, Mo{sub 2}B{sub 5}, and MoB{sub 4}) was performed by self-propagating high-temperature synthesis (SHS) with two kinds of the reactant samples. When elemental powder compacts with an exact stoichiometry corresponding to the boride phase were employed, self-sustaining reaction was only achieved in the sample with Mo:B = 1:1 and nearly single-phase MoB was yielded. Therefore, the other four boride compounds were prepared from the reactant compacts composed of MoO{sub 3}, Mo, and B powders, within which the displacement reaction of MoO{sub 3} with boron was involved in combustion synthesis. Experimental evidence shows that the extent of displacement reaction in the overall reaction has a significant impact on sustainability of the synthesis reaction, combustion temperature, reaction front velocity, and composition of the end product. An increase in the solid-phase displacement reaction taking place during the SHS process contributes more heat flux to the synthesis reaction, thus resulting in the increase of combustion temperature and enhancement of the reaction front velocity. Based upon the XRD analysis, formation of Mo{sub 2}B, MoB{sub 2}, and Mo{sub 2}B{sub 5} as the dominant boride phase in the end product was successful through the SHS reaction with powder compacts under appropriate stoichiometries between MoO{sub 3}, Mo, and B. However, a poor conversion was observed in the synthesis of MoB{sub 4}. The powder compact prepared for the production of MoB{sub 4} yielded mostly Mo{sub 2}B{sub 5}.

  9. Investigation on Indium-Filled Skutterudite Materials Prepared by Combining Hydrothermal Synthesis and Hot Pressing

    Science.gov (United States)

    Du, Y.; Cai, K. F.; Chen, S.; Qin, Z.; Shen, S. Z.

    2011-05-01

    Indium-filled CoSb3 materials have been investigated by combining hydrothermal synthesis and hot pressing. The materials were prepared as follows. Corresponding nanopowders were synthesized by a hydrothermal synthesis method, in some cases followed by melting at 1373 K, and then hot pressed at 923 K. The phase composition and microstructure of the bulk materials were analyzed by conventional methods, such as x-ray diffraction (XRD), scanning electron microscopy (SEM), and field-emission SEM equipped with energy-dispersive x-ray spectroscopy (EDS). The thermoelectric properties of the bulk materials were measured from room temperature to 773 K. The results reveal that indium can be successfully filled into the voids of the CoSb3 structure when the sample preparation procedure contains melting. The influence of the processing on the thermoelectric properties of the materials is also discussed.

  10. Er:SrF{sub 2} luminescent powders prepared by combustion synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Rakov, Nikifor, E-mail: nkifor.gomez@univasf.edu.br [PG - Ciencia dos Materiais, Universidade Federal do Vale do Sao Francisco, 48902-300 Juazeiro, BA (Brazil); Guimaraes, R.B.; Franceschini, D.F.; Maciel, Glauco S. [Instituto de Fisica, Universidade Federal Fluminense, 24210-346 Niteroi, RJ (Brazil)

    2012-08-15

    Combustion synthesis, a widely spread technique employed to produce low-cost high-yield oxide powders, was used to prepare fluoride powders for the first time. Surface morphology and structure of erbium (Er{sup 3+}) doped strontium fluoride (SrF{sub 2}) powders were investigated by scanning electronic microscopy, energy dispersive X-ray and X-ray powder diffraction. Samples were prepared with and without aluminum (Al) and we observed that the presence of Al helps the powder to crystallize in a pure SrF{sub 2} single cubic phase. Luminescence spectral analysis was also performed and we observed that among the samples investigated the Er{sup 3+}:SrF{sub 2} powder prepared with Al using glycine is the most efficient luminescence up-converter. The luminescence results concords with Raman data of the samples. -- Highlights: Black-Right-Pointing-Pointer Strontium fluoride powders are prepared by combustion synthesis for the first time. Black-Right-Pointing-Pointer Structural characterization and luminescence analysis of powders prepared using two different fuels: glycine and urea. Black-Right-Pointing-Pointer Analysis of the influence of aluminum on the powders structure and luminescence properties. Black-Right-Pointing-Pointer First time, to the best of our knowledge, that Raman spectroscopy is performed in SrF{sub 2} nanostructured material.

  11. Biochemical Preparation of Cell Extract for Cell-Free Protein Synthesis without Physical Disruption.

    Directory of Open Access Journals (Sweden)

    Kei Fujiwara

    Full Text Available Cell-free protein synthesis (CFPS is a powerful tool for the preparation of toxic proteins, directed protein evolution, and bottom-up synthetic biology. The transcription-translation machinery for CFPS is provided by cell extracts, which usually contain 20-30 mg/mL of proteins. In general, these cell extracts are prepared by physical disruption; however, this requires technical experience and special machinery. Here, we report a method to prepare cell extracts for CFPS using a biochemical method, which disrupts cells through the combination of lysozyme treatment, osmotic shock, and freeze-thaw cycles. The resulting cell extracts showed similar features to those obtained by physical disruption, and was able to synthesize active green fluorescent proteins in the presence of appropriate chemicals to a concentration of 20 μM (0.5 mg/mL.

  12. Effects of Catalyst Preparation on Hydrocarbon Product Distribution in Hydrocracking of the Fischer-Tropsch Product with Low Pt-Loaded Catalysts

    Directory of Open Access Journals (Sweden)

    Toshiaki Hanaoka

    2015-11-01

    Full Text Available For the effective production of hydrocarbon liquid fuel in the hydrocracking of the Fischer-Tropsch (FT product, the catalytic performance of Pt-loaded catalysts with low Pt content was investigated using an autoclave at 250 °C, an initial H2 pressure of 0.5 MPa, and a reaction time of 1 h. A screening study using Pt-loaded catalysts with a Pt content of 0.1 wt. % indicated that zeolite supports were more favorable for jet fuel (carbon numbers 9–15 production than amorphous oxide supports. The small particle size of the supported Pt particles and the high amount of medium acid sites for the supports led to higher performance of the Pt-loaded zeolite catalysts. In the hydrocracking reaction over Pt catalysts using the zeolite support with the high amount of medium acid sites, the yields of the corresponding jet fuel at 0.02 and 0.1 wt. % were almost the same. Pt-loaded catalysts with a Pt content of 0.02 wt. % were prepared using water-in-oil (w/o microemulsions and their particle size was controlled between 1.0 and 2.6 nm. While the yield of the corresponding jet fuel was independent of Pt particle size, smaller Pt particles typically promoted the production of lighter hydrocarbons.

  13. The first preparative solution phase synthesis of melanotan II

    Directory of Open Access Journals (Sweden)

    2008-10-01

    Full Text Available Melanotan II is a synthetic cyclic heptapeptide used to prevent a sunlight-induced skin cancer by stimulating the skin tanning process. In this paper we report the first solution phase synthesis of the title compound. The hexapeptide sequence has been assembled by [(2+2+1+1] scheme. After removing the orthogonal protection, a carbodiimide mediated lactamization, involving the ε-amino group of lysine and γ-carboxy group of aspartic acid, led to a cyclic intermediate. Appending N-acetylnorleucine concluded the assembly of melanotan II molecule. Protection of the lateral groups in arginine and tryptophan was omitted for atom and step economy reasons. The total synthesis of melanotan II was accomplished in 12 steps with 2.6% overall yield, affording >90% pure peptide without using preparative chromatography.

  14. Preparation of sound base for a text-to-speech synthesis system

    Science.gov (United States)

    Degtyarev, Vladimir M.; Gusev, Mikhail N.

    2005-04-01

    We are giving several recommendations for the choice of parameters of the sound fragments in this report. The sound fragments are components of the sound base, used in Russian speech synthesis system by a text. It isn't the secret that quality of concatenation synthesis in many respects is defined at the stage of a speaker choice and preparation of base of speaker's voice samples. Formulated recommendations are received on the basis of the statistic analysis of big amount of various types of texts and concern both separate sound fragments and their groups. Parameters of sounds were taken with the help of the automatic linguistic processor including phonetic and prosodic transcriptors. The duration, intensity and main pitch frequency of sounds in various contexts and intonational contours were analyzed. The sound base produced according to the worked out recommendations, allows to make better intelligibility and naturalness of synthetic speech due to minimization of changes of speaker's voice samples.

  15. A Simple and Rapid Method for Preparing a Cell-Free Bacterial Lysate for Protein Synthesis.

    Directory of Open Access Journals (Sweden)

    Nitzan Krinsky

    Full Text Available Cell-free protein synthesis (CFPS systems are important laboratory tools that are used for various synthetic biology applications. Here, we present a simple and inexpensive laboratory-scale method for preparing a CFPS system from E. coli. The procedure uses basic lab equipment, a minimal set of reagents, and requires less than one hour to process the bacterial cell mass into a functional S30-T7 extract. BL21(DE3 and MRE600 E. coli strains were used to prepare the S30-T7 extract. The CFPS system was used to produce a set of fluorescent and therapeutic proteins of different molecular weights (up to 66 kDa. This system was able to produce 40-150 μg-protein/ml, with variations depending on the plasmid type, expressed protein and E. coli strain. Interestingly, the BL21-based CFPS exhibited stability and increased activity at 40 and 45°C. To the best of our knowledge, this is the most rapid and affordable lab-scale protocol for preparing a cell-free protein synthesis system, with high thermal stability and efficacy in producing therapeutic proteins.

  16. Preparing compound heterozygous reference material using gene synthesis technology: a model of thrombophilic mutations.

    Science.gov (United States)

    Beranek, Martin; Drastikova, Monika; Dulicek, Petr; Palicka, Vladimir

    2014-12-01

    The aim of our study is to present a novel approach for preparing a compound heterozygous reference material (hetRM) using gene synthesis technology with inverted insertion of wild-type and mutant fragments into a single cloning vector. Factor II (G20210A) and Factor V (G1691A Leiden) gene mutations were used as an experimental model. During the gene synthesis, DNA fragments were aligned in the following order: G1691 FV wild-type forward strain, G20210 FII wild-type forward strain, 1691A FV mutant reverse strain, 20210A FII mutant reverse strain. The complete chain was inserted into a pIDT SMART cloning vector and amplified in an E. coli competent strain. For assessing hetRM characteristics and commutability, we used real-time PCR with subsequent melting curve analysis, real-time PCR with hydrolysis probes, allele-specific amplification, reverse hybridization, and dideoxynucleotide DNA sequencing. All five methods yielded concordant results of DNA analysis of the hetRM. Differences in real-time PCR cycle threshold values after six-months of storage at -80 °C were not statistically significant from those obtained from freshly prepared hetRM aliquots, which is a good indication of their stability. By applying the procedures of gene synthesis and cloning technology, we prepared and verified a model genetic reference material for FII G20210A and FV G1691A testing with a compound heterozygous genotype. The hetRM was stable, commutable, and available in large quantities and in a wide concentration range.

  17. Mechanochemical preparation of hydantoins from amino esters: application to the synthesis of the antiepileptic drug phenytoin.

    Science.gov (United States)

    Konnert, Laure; Reneaud, Benjamin; de Figueiredo, Renata Marcia; Campagne, Jean-Marc; Lamaty, Frédéric; Martinez, Jean; Colacino, Evelina

    2014-11-07

    The eco-friendly preparation of 5- and 5,5-disubstituted hydantoins from various amino ester hydrochlorides and potassium cyanate in a planetary ball-mill is described. The one-pot/two-step protocol consisted in the formation of ureido ester intermediates, followed by a base-catalyzed cyclization to hydantoins. This easy-handling mechanochemical methodology was applied to a large variety of α- and β-amino esters, in smooth conditions, leading to hydantoins in good yields and with no need of purification steps. As an example, the methodology was applied to the "green" synthesis of the antiepileptic drug Phenytoin, with no use of any harmful organic solvent.

  18. Bismuth molybdate catalysts prepared by mild hydrothermal synthesis: Influence of pH on the selective oxidation of propylene

    DEFF Research Database (Denmark)

    Schuh, Kirsten; Kleist, Wolfgang; Høj, Martin

    2015-01-01

    A series of bismuth molybdate catalysts with relatively high surface area was prepared via mild hydrothermal synthesis. Variation of the pH value and Bi/Mo ratio during the synthesis allowed tuning of the crystalline Bi-Mo oxide phases, as determined by X-ray diffraction (XRD) and Raman spectrosc...... support that a combination of the required bismuth molybdate phase and a high specific surface area is crucial for a good performance in the selective oxidation of propylene....

  19. 21 CFR 178.3530 - Isoparaffinic petroleum hydrocarbons, synthetic.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Isoparaffinic petroleum hydrocarbons, synthetic... hydrocarbons, synthetic. Isoparaffinic petroleum hydrocarbons, synthetic, may be safely used in the production... isoparaffinic petroleum hydrocarbons, produced by synthesis from petroleum gases consist of a mixture of liquid...

  20. Synthesis and preparation of biocompatible and pH-responsive cyclodextrin-based nanoparticle

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Xiaohong, E-mail: huxiaohong07@163.com; Chen, Shangneng [Jinling Institute of Technology, School of Material Engineering (China); Gong, Xiao [Wuhan University of Technology, State Key Laboratory of Silicate Materials for Architectures (China); Gao, Ziyu; Wang, Xin; Chen, Pin [Jinling Institute of Technology, School of Material Engineering (China)

    2017-03-15

    As a temporarily protective reaction for active hydrogen group, acetylation is reversible and responsive to low pH value. According to the reaction, pH-sensitive β-cyclodextrin (β-CD) was synthesized in the first step of our research. During the synthesis, the acetal groups including linear acetal (LA) groups and cyclic acetal (CA) groups were successfully modified onto β-CD. Particularly, the structural details of acetalated β-CD (Ac-β-CD) were greatly influenced by reaction time. Furthermore, in respect to water solubility, Ac-β-CDs exhibited different pH response properties due to their different structure. In the second step, Ac-β-CD1 nanoparticles were prepared by a single oil-in-water (O/W) emulsion technique using a biocompatible emulsifier, gelatin. Meanwhile, gelatin was absorbed onto the surface of nanoparticle, which was confirmed by FTIR spectra. The formed nanoparticles showed monodispersion and nearly spherical morphology. In order to obtain optimal preparing conditions, the effects of preparative parameters such as gelatin concentration, Ac-β-CD concentration, and water/oil ratio on properties including diameters and zeta potential as well as gelatin content were investigated. Moreover, the pH response properties of nanoparticle were characterized by transparency of nanoparticle solution. Finally, in vitro cell culture confirmed that Ac-β-CD nanoparticle could support cell survival and enhance cell viability.

  1. High-Quality ZnCdS Nanosheets Prepared Using Solvothermal Synthesis

    Directory of Open Access Journals (Sweden)

    M. A. Mahdi

    2013-01-01

    Full Text Available For the first time, ZnxCd1-xS nanosheets with different Zn and Cd ion concentrations were prepared using solvothermal synthesis at 200°C for 4 and 24 h. The crystalline structure of the nanosheets was wurtzite. The optical band gaps of the nanosheets increased with increasing Zn ratio; this increase is consistent with the band gaps estimated using Vegard’s formula. The photoluminescence spectra for the 24 h nanosheets had higher emission intensities than those for the 4 h nanosheets. The emission band corresponding to intrinsic near-band-edge emission and a broad peak associated with extrinsic deep-level emission were observed in the photoluminescence spectra.

  2. Indium oxide cubes prepared by hydrothermal synthesis as catalysts for CO oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Mu Yao [Department of Physics, South University of Science and Technology of China, Shenzhen (China); Department of Physics, The University of Hong Kong, Pokfulam Road (Hong Kong); Liu, Fangzhou [Department of Physics, The University of Hong Kong, Pokfulam Road (Hong Kong); Tsui, Jenkin; Voskanyan, Albert A. [Department of Chemistry, The University of Hong Kong, Pokfulam Road (Hong Kong); Ng, Alan Man Ching, E-mail: ngamc@sustc.edu.cn [Department of Physics, South University of Science and Technology of China, Shenzhen (China); Department of Physics, The University of Hong Kong, Pokfulam Road (Hong Kong); Djurišić, Aleksandra B., E-mail: dalek@hku.hk [Department of Physics, The University of Hong Kong, Pokfulam Road (Hong Kong); Chan, Wai Kin; Chan, Kwong-Yu [Department of Chemistry, The University of Hong Kong, Pokfulam Road (Hong Kong)

    2015-03-01

    Indium oxide cubes have been prepared by hydrothermal synthesis. The cubes exhibited significantly better catalytic activity towards CO oxidation compared to commercial In{sub 2}O{sub 3} powder and nanoparticles. With the addition of a metal co-catalyst, the performance could be further improved, with the T{sub 50} temperatures (temperature at which 50% of CO is converted) obtained for different metals exhibiting the following trend: Pd > Cu > Pt. The obtained results clearly demonstrate the potential of In{sub 2}O{sub 3} as an active oxide support for CO oxidation. - Highlights: • In{sub 2}O{sub 3} cubes were synthesized by a simple hydrothermal method. • Improvement in CO oxidation compared to commercial powder and nanoparticles. • Further improvement was obtained by impregnation with metal catalyst. • Half conversion temperature below 200 °C was first achieved for In{sub 2}O{sub 3} based catalyst.

  3. Vacuum ultraviolet and visible spectra of ZnO:Eu{sup 3+} prepared by combustion synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Cheng Bingming [National Synchrotron Radiation Research Centre, Hsinchu, Taiwan (China); Yu Lixin; Duan Changkui; Wang, Huaishan; Tanner, Peter A [Department of Biology and Chemistry, City University of Hong Kong, Kowloon (Hong Kong)], E-mail: bhtan@cityu.edu.hk

    2008-08-27

    Zinc oxide doped with 1 at.% Eu{sup 3+} has been prepared by combustion synthesis using several different reductants. Samples sintered at 800 deg. C were {approx}30 nm in size and Fourier transform IR spectra demonstrated that they were relatively free of contaminants. Ultraviolet and near-ultraviolet laser excited emission spectra showed that Eu{sup 3+} ions are disordered and not situated at discrete lattice sites in ZnO and consequently no evidence for energy transfer from the host to Eu{sup 3+} was found. Vacuum ultraviolet (VUV) excitation produced defect site emission in addition to near-band-edge emission but the intensity of the Eu{sup 3+} visible emission was very weak. Bands between 6.2 and 9.1 eV in the VUV excitation spectra have been assigned to electric dipole allowed transitions, 3d-4p.

  4. Synthesis and characterization of chemically and electrochemically prepared conducting polymer/iron oxalate composites

    Energy Technology Data Exchange (ETDEWEB)

    Visy, Csaba [Institute of Physical Chemistry, University of Szeged, P.O. Box 105, H-6701 Szeged (Hungary)], E-mail: visy@chem.u-szeged.hu; Bencsik, Gabor [Institute of Physical Chemistry, University of Szeged, P.O. Box 105, H-6701 Szeged (Hungary); Nemeth, Zoltan; Vertes, Attila [Department of Nuclear Chemistry, Eoetvoes Lorand University, P.O. Box 32, 1518 Budapest (Hungary)

    2008-04-20

    Poly(3-octyl-thiophene) (POT) and polypyrrole (PPy) iron oxalate composites were synthesized through a post-polymerization oxidative treatment. The composite of the latter has been prepared also by electrochemical polymerization. The samples have been characterized by X-ray diffraction (XRD), impedance spectroscopy, scanning electron microscope (SEM) combined with energy dispersive X-ray (EDX) spectroscopy, Moessbauer spectroscopy, cyclic voltammetry and electrochemical quartz crystal microbalance (EQCM). In case of PPy, two peaks in the XRD spectra show the presence of iron containing composite, while with POT only the layered structure originating from the octyl side-chain interactions was modified by the composite formation. The assumption of the weakening of short- and long-range interactions was proven by the decrease in conductivity of the composite. The successful electrochemical synthesis resulted a composite of {approx}5% iron content, determined by EDX. Moessbauer spectroscopy measurements evidenced a composite containing mixed valence iron oxalate doping ions, which supports the indirect EQCM data.

  5. Synthesis of Hydrocarbons from H2-Deficient Syngas in Fischer-Tropsch Synthesis over Co-Based Catalyst Coupled with Fe-Based Catalyst as Water-Gas Shift Reaction

    Directory of Open Access Journals (Sweden)

    Ting Ma

    2015-01-01

    Full Text Available The effects of metal species in an Fe-based catalyst on structural properties were investigated through the synthesis of Fe-based catalysts containing various metal species such, as Mn, Zr, and Ce. The addition of the metal species to the Fe-based catalyst resulted in high dispersions of the Fe species and high surface areas due to the formation of mesoporous voids about 2–4 nm surrounded by the catalyst particles. The metal-added Fe-based catalysts were employed together with Co-loaded beta zeolite for the synthesis of hydrocarbons from syngas with a lower H2/CO ratio of 1 than the stoichiometric H2/CO ratio of 2 for the Fischer-Tropsch synthesis (FTS. Among the catalysts, the Mn-added Fe-based catalyst exhibited a high activity for the water-gas shift (WGS reaction with a comparative durability, leading to the enhancement of the CO hydrogenation in the FTS in comparison with Co-loaded beta zeolite alone. Furthermore, the loading of Pd on the Mn-added Fe-based catalyst enhanced the catalytic durability due to the hydrogenation of carbonaceous species by the hydrogen activated over Pd.

  6. Synthesis of amino-functionalized silica nanoparticles for preparation of new laboratory standards

    Science.gov (United States)

    Alvarez-Toral, Aitor; Fernández, Beatriz; Malherbe, Julien; Claverie, Fanny; Pecheyran, Christophe; Pereiro, Rosario

    2017-12-01

    Platinum group elements (PGEs) are particularly interesting analytes in different fields, including environmental samples as well as high cost materials that contain them, such as for example automotive catalysts. This type of solid samples could be analysed by laser ablation (LA) coupled to ICP-MS, which allow to significantly reducing the analysis time since the time-consuming processes for sample preparation are not required. There is a considerable demand of standards with high PGEs concentration for quantification purposes, which cannot be carried out easily using LA-ICP-MS because the available standards (i.e. NIST SRM 61 × series) do not have such analytes in the same concentration range. In this paper, a new strategy is proposed for the synthesis of homogeneous laboratory standards with Pt, Pd and Rh concentrations that range from 77 μg/g of Pd up to 2035 μg/g of Rh. The proposed strategy is based on the synthesis of monodisperse amino-functionalized amorphous silica nanoparticles, which can retain metal ions. In addition to Pt, Pd and Rh, three lanthanides were also added to the nanoparticles (La, Ce, Nd). Sturdy pressed pellets can be made from the resulting nanopowder without the use of any binder. Elemental composition of standards made of nanoparticles was analysed by conventional nebulization ICP-MS and their homogeneity was successfully evaluated by LA-ICP-MS.

  7. Sample preparation of sewage sludge and soil samples for the determination of polycyclic aromatic hydrocarbons based on one-pot microwave-assisted saponification and extraction

    Energy Technology Data Exchange (ETDEWEB)

    Pena, M.T.; Pensado, Luis; Casais, M.C.; Mejuto, M.C.; Cela, Rafael [Universidad de Santiago de Compostela, Dpto. Quimica Analitica, Nutricion y Bromatologia. Instituto de Investigacion y Analisis Alimentario, Santiago de Compostela (Spain)

    2007-04-15

    A microwave-assisted sample preparation (MASP) procedure was developed for the analysis of polycyclic aromatic hydrocarbons (PAHs) in sewage sludge and soil samples. The procedure involved the simultaneous microwave-assisted extraction of PAHs with n-hexane and the hydrolysis of samples with methanolic potassium hydroxide. Because of the complex nature of the samples, the extracts were submitted to further cleaning with silica and Florisil solid-phase extraction cartridges connected in series. Naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[e]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenz[a,h]anthracene, benzo[g,h,i]perylene, and indeno[1,2,3-cd]pyrene, were considered in the study. Quantification limits obtained for all of these compounds (between 0.4 and 14.8 {mu}g kg{sup -1} dry mass) were well below of the limits recommended in the USA and EU. Overall recovery values ranged from 60 to 100%, with most losses being due to evaporation in the solvent exchange stages of the procedure, although excellent extraction recoveries were obtained. Validation of the accuracy was carried out with BCR-088 (sewage sludge) and BCR-524 (contaminated industrial soil) reference materials. (orig.)

  8. Preparation, characterization and catalytic properties of MCM-48 supported tungstophosphoric acid mesoporous materials for green synthesis of benzoic acid

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Hai-Yan; Zhang, Xiao-Li; Chen, Xi; Chen, Ya; Zheng, Xiu-Cheng, E-mail: zhxch@zzu.edu.cn

    2014-03-15

    MCM-48 and tungstophosphoric acid (HPW) were prepared and applied for the synthesis of HPW/MCM-48 mesoporous materials. The characterization results showed that HPW/MCM-48 obtained retained the typical mesopore structure of MCM-48, and the textural parameters decreased with the increase loading of HPW. The catalytic oxidation results of benzyl alcohol and benzaldehyde with 30% H{sub 2}O{sub 2} indicated that HPW/MCM-48 was an efficient catalyst for the green synthesis of benzoic acid. Furthermore, 35 wt% HPW/MCM-48 sample showed the highest activity under the reaction conditions. Highlights: • 5–45 wt% HPW/MCM-48 mesoporous catalysts were prepared and characterized. • Their catalytic activities for the green synthesis of benzoic acid were investigated. • HPW/MCM-48 was approved to be an efficient catalyst. • 5 wt% HPW/MCM-48 exhibited the highest catalytic activity.

  9. Facile synthesis of N-acyl-aminoacyl-pCpA for preparation of mischarged fully ribo tRNA.

    Science.gov (United States)

    Kwiatkowski, Marek; Wang, Jinfan; Forster, Anthony C

    2014-11-19

    Chemical synthesis of N-acyl-aminoacyl-pdCpA and its ligation to tRNA(minus CA) is widely used for the preparation of unnatural aminoacyl-tRNA substrates for ribosomal translation. However, the presence of the unnatural deoxyribose can decrease incorporation yield in translation and there is no straightforward method for chemical synthesis of the natural ribo version. Here, we show that pCpA is surprisingly stable to treatment with strong organic bases provided that anhydrous conditions are used. This allowed development of a facile method for chemical aminoacylation of pCpA. Preparative synthesis of pCpA was also simplified by using t-butyl-dithiomethyl protecting group methodology, and a more reliable pCpA postpurification treatment method was developed. Such aminoacyl-pCpA analogues ligated to tRNA(minus CA) transcripts are highly active in a purified translation system, demonstrating utility of our synthetic method.

  10. Preparation of fluorescent DNA probe by solid-phase organic synthesis

    Directory of Open Access Journals (Sweden)

    2009-08-01

    Full Text Available Fluorescent DNA probe based on fluorescence resonance energy transfer (FRET was prepared by solid-phase organic synthesis when CdTe quantum dots (QDs were as energy donors and Au nanoparticles (AuNPs were as energy accepters. The poly(divinylbenzene core/poly(4-vinylpyridine shell microspheres, as solid-phase carriers, were prepared by seeds distillation-precipitation polymerization with 2,2′-azobisisobutyronitrile (AIBN as initiator in neat acetonitrile. The CdTe QDs and AuNPs were self-assembled on the surface of core/shell microspheres, and then the linkage of CdTe QDs with oligonucleotides (CdTe-DNA and AuNPs with complementary single-stranded DNA (Au-DNA was on the solid-phase carriers instead of in aqueous solution. The hybridization of complementary double stranded DNA (dsDNA bonded to the QDs and AuNPs (CdTe-dsDNA-Au determined the FRET distance of CdTe QDs and AuNPs. Compared with the fluorescence of CdTe-DNA, the fluorescence of CdTe-dsDNA-Au conjugates (DNA probes decreased extremely, which indicated that the FRET occurred between CdTe QDs and AuNPs. The probe system would have a certain degree recovery of fluorescence when the complementary single stranded DNA was introduced into this system, which showed that the distance between CdTe QDs and AuNPs was increased.

  11. Thermoluminescence study of aluminium oxide doped germanium prepared by combustion synthesis method

    Directory of Open Access Journals (Sweden)

    Saharin Nurul Syazlin Binti

    2017-01-01

    Full Text Available The present paper reports the optimum concentration of germanium (Ge dopant in aluminium oxide (AhO3 samples prepared by combustion synthesis (CS method for thermoluminescence (TL studies. The samples were prepared at various Ge concentration i.e. 1 to 5% mol. The phase formation of un-doped and Ge-doped Al2O3 samples was determined using X-ray Diffraction (XRD. The sharp peaks present in the XRD pattern confirms the crystallinity of the samples. The samples were then exposed to 50 Gy Cobalt-60 sources (Gamma cell 220. TL glow curves were measured and recorded using a Harshaw Model 3500 TLD reader. Comparison of TL peaks were observed to obtain the best composition of Ge dopants. A simple glow curves TL peak at around 175̊C for all composition samples was observed. It was also found that the composition of aluminium oxide doped with 3.0% of germanium exhibits the highest thermoluminescence (TL intensity which is 349747.04 (a.u.

  12. Preparation of biomorphic silicon carbide–mullite ceramics using molten salt synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei, E-mail: wwchem@126.com [Department of Chemical Engineering, College of Environment Science and Engineering, Key Laboratory of Subsurface Hydrology and Ecology in Arid Areas, Ministry of Education, Chang’an University, 126# Yanta Road, Xi' an 710054, Shaanxi (China); Hou, Guangya [College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310014 (China); Wang, Boya; Deng, Shunxi [Department of Chemical Engineering, College of Environment Science and Engineering, Key Laboratory of Subsurface Hydrology and Ecology in Arid Areas, Ministry of Education, Chang’an University, 126# Yanta Road, Xi' an 710054, Shaanxi (China)

    2014-09-15

    Biomorphic silicon carbide–mullite ceramics were prepared from beech wood using liquid Si infiltration and molten salts synthesis. The resulting mullite whiskers coating, as well as the growth mechanism in molten Al{sub 2}(SO{sub 4}){sub 3}–Na{sub 2}SO{sub 4} environment, have been investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) techniques. The biomorphic SiC ceramics derived from the beech wood template have coarse pore walls consisting of β-SiC grains with diameters ranging from 5 μm to 20 μm. After the molten salts reactions between biomorphic SiC substrate and mixture molten salts (Al{sub 2}(SO{sub 4}){sub 3}–Na{sub 2}SO{sub 4}), porous Silicon carbide–mullite ceramics with cilia-like microstructure were obtained. This unique structure has potential application in hot gases filters. An oxidation–dissolution cycle was proposed to explain the mullite whiskers growth in molten salts environment. - Graphical abstract: Biomorphic silicon carbide–mullite ceramics with cilia-like microstructure prepared from beech wood using liquid Si infiltration (LSI) and molten salts reactions (MSR) processes. Mullite whiskers with nanometer-sized diameters and micrometer-sized lengths grow on the surface of SiC substrate, and the biomorphic silicon carbide–mullite ceramics inherit the porous microstructure originated from biomorphic SiC ceramics and beech wood. The mullite whiskers grow on the pores' surface of biomorphic SiC to form cilia-like surface, and this special structure can be used for hot gases filter. - Highlights: • Biomorphic silicon carbide–mullite ceramics were prepared. • An oxidation–dissolution mechanism was proposed to explain the coating formation. • The unique structure has potential application in hot gases filter.

  13. Synthesis of Potential Metaboliters in the 1,2,3,4, and 5,6,7,8 Benzo Ring Positions of the Polycyclic Aromatic Hydrocarbon Benzo(G)Chrysene.

    Science.gov (United States)

    1986-01-01

    benzo ring face as the benzylic carbinol proton (cis, series 1). The second method is direct epoxidation of the dihydrodiol using peroxyacids . Qne... peroxyacids . However, we weren’t successful in obtaining exclusive formation of trans diol epoxide XXVII. Initial attempts at preparing XXVII followed...prepared by peroxyacid oxidations of dihydro derivatives of polycyclic aromatic hydrocarbons or by bromohydrin/dehydrobromination routes. Because of the

  14. Bioassay of polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Van Kirk, E.A.

    1980-08-01

    A positive relationship was found between the photodynamic activity of 24 polycyclic aromatic hydrocarbons versus published results on the mutagenicity, carcinogenicity, and initiation of unscheduled DNA synthesis. Metabolic activation of benzo(a)pyrene resulted in detection of increased mutagenesis in Paramecium tetraurelia as found also in the Ames Salmonella assay. The utility of P. tetraurelia as a biological detector of hazardous polycyclic aromatic hydrocarbons is discussed.

  15. Syngas Upgrading to Hydrocarbon Fuels Technology Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Talmadge, M.; Biddy, M.; Dutta, A.; Jones, S.; Meyer, A.

    2013-03-01

    This technology pathway case investigates the upgrading of woody biomass derived synthesis gas (syngas) to hydrocarbon biofuels. While this specific discussion focuses on the conversion of syngas via a methanol intermediate to hydrocarbon blendstocks, there are a number of alternative conversion routes for production of hydrocarbons through a wide array of intermediates from syngas. Future work will also consider the variations to this pathway to determine the most economically viable and lowest risk conversion route. Technical barriers and key research needs have been identified that should be pursued for the syngas-to-hydrocarbon pathway to be competitive with petroleum-derived gasoline-, diesel- and jet-range hydrocarbon blendstocks.

  16. Study of the first paramagnetic to ferromagnetic transition in as prepared samples of Mn–Fe–P–Si magnetocaloric compounds prepared by different synthesis routes

    Energy Technology Data Exchange (ETDEWEB)

    Bartok, A., E-mail: andras.bartok@satie.ens-cachan.fr [SATIE, ENS Cachan, CNRS, Universite Paris-Saclay, 61 av President Wilson, F-94230 Cachan (France); Kustov, M.; Cohen, L.F. [Imperial College, London SW7 2AZ (United Kingdom); Pasko, A. [SATIE, ENS Cachan, CNRS, Universite Paris-Saclay, 61 av President Wilson, F-94230 Cachan (France); Zehani, K.; Bessais, L. [CMTR, ICMPE, CNRS-UPEC, 2-8 rue Henri Dunant, F-94320 Thiais (France); Mazaleyrat, F.; LoBue, M. [SATIE, ENS Cachan, CNRS, Universite Paris-Saclay, 61 av President Wilson, F-94230 Cachan (France)

    2016-02-15

    Magnetocaloric materials with composition of Mn{sub 1.3}Fe{sub 0.65}P{sub 0.5} Si{sub 0.5} have been prepared by ball milling and solid-state reaction methods and consolidated using powder annealing, and conventional and spark plasma sintering. Magnetic and calorimetric measurements show remarkable differences upon first cooling, and slight differences on second and further coolings between the samples prepared by different synthesis routes. Further measurements using Hall probe imaging in high magnetic field have been also carried out. As-prepared samples have been cooled down just above the critical temperature, and the first phase transition has been induced by application of a magnetic field. Bulk samples show staircase isothermal magnetization curves whereas powders show smoother transition curves. - Highlights: • Mn–Fe–P–Si magnetocaloric materials have been prepared by different synthesis routes. • Magnetic measurements show remarkable differences upon first cooling. • First phase transition has been induced by application of a magnetic field. • Hall probe imaging in high magnetic field has also been carried out. • Bulk samples crack during the first PM–FM transition.

  17. Investigating the Heavy Metal Adsorption of Mesoporous Silica Materials Prepared by Microwave Synthesis

    Science.gov (United States)

    Zhu, Wenjie; Wang, Jingxuan; Wu, Di; Li, Xitong; Luo, Yongming; Han, Caiyun; Ma, Wenhui; He, Sufang

    2017-05-01

    Mesoporous silica materials (MSMs) of the MCM-41 type were rapidly synthesized by microwave heating using silica fume as silica source and evaluated as adsorbents for the removal of Cu2+, Pb2+, and Cd2+ from aqueous solutions. The effects of microwave heating times on the pore structure of the resulting MSMs were investigated as well as the effects of different acids which were employed to adjust the solution pH during the synthesis. The obtained MCM-41 samples were characterized by nitrogen adsorption-desorption analyses, X-ray powder diffraction, and transmission electron microscopy. The results indicated that microwave heating method can significantly reduce the synthesis time of MCM-41 to 40 min. The MCM-41 prepared using citric acid (c-MCM-41(40)) possessed more ordered hexagonal mesostructure, higher pore volume, and pore diameter. We also explored the ability of c-MCM-41(40) for removing heavy metal ions (Cu2+, Pb2+, and Cd2+) from aqueous solution and evaluated the influence of pH on its adsorption capacity. In addition, the adsorption isotherms were fitted by Langmuir and Freundlich models, and the adsorption kinetics were assessed using pseudo-first-order and pseudo-second-order models. The intraparticle diffusion model was studied to understand the adsorption process and mechanism. The results confirmed that the as-synthesized adsorbent could efficiently remove the heavy metal ions from aqueous solution at pH range of 5-7. The adsorption isotherms obeyed the Langmuir model, and the maximum adsorption capacities of the adsorbent for Cu2+, Pb2+, and Cd2+ were 36.3, 58.5, and 32.3 mg/g, respectively. The kinetic data were well fitted to the pseudo-second-order model, and the results of intraparticle diffusion model showed complex chemical reaction might be involved during adsorption process.

  18. Synthesis and properties of nasicon prepared from different zirconia-based precursors

    Directory of Open Access Journals (Sweden)

    Fuentes, R. O.

    1999-12-01

    Full Text Available This work reports on the synthesis and characterization of NASICON prepared from SiO2, Na3PO4.12H2O and two types of zirconia: pure monoclinic ZrO2 and TZP (Tetragonal Polycrystalline Zirconia, with 3 mol% Y2O3 as raw materials. The classical ceramic method was used in all cases. SEM, XRD and DTA were used to follow the synthesis and sintering process, and impedance spectroscopy (IS was used to study the electrical properties of sintered pellets. Results obtained with different NASICON samples showed a significant role of composition and processing conditions on the electrical properties. Samples based on TZP, sintered at 1210ºC, exhibited densities of about 3.20 g/cm3 (98% of theoretical density of NASICON and ionic conductivities of about 2x10-3 S.cm-1 at room temperature a rather interesting result when compared with data obtained with the material prepared from pure ZrO2.

    Este trabajo trata de la síntesis y caracterización de NASICON preparado a partir de SiO2 , Na3PO4.12H2O y dos tipos de circonia, ZrO2 monoclínica pura y TZP (circonia policristalina tetragonal, con 3 moles% Y2O3 como materia prima. Se emplea el método cerámico clásico en todos los casos. Las técnicas de MEB, DRX y ATD se emplean para seguir la síntesis y el proceso de sinterización. La espectroscopia de impedancia compleja se emplea para estudiar las propiedades eléctricas de las muestras sinterizadas. Los resultados obtenidos con diferentes muestras de NASICON mostraron un papel significativo de la composición y condiciones de procesamiento sobre las propiedades eléctricas. Las muestras basadas en TZP, sinterizadas a 1210ºC, presentan densidades alrededor de 3.20 g/cm3 (98% de la densidad teórica del NASICON y conductividad iónica de 2x 10-3 5.cm-1 a temperatura ambiente, un resultado bastante interesante cuando se compara con datos obtenidos con material preparado de ZrO2 pura.

  19. Fischer-Tropsch catalysts for the production of hydrocarbon fuels with high selectivity.

    Science.gov (United States)

    Zhang, Qinghong; Cheng, Kang; Kang, Jincan; Deng, Weiping; Wang, Ye

    2014-05-01

    Fischer-Tropsch synthesis is a key reaction in the utilization of non-petroleum carbon resources, such as methane (natural gas, shale gas, and biogas), coal, and biomass, for the sustainable production of clean liquid fuels from synthesis gas. Selectivity control is one of the biggest challenges in Fischer-Tropsch synthesis. This Minireview focuses on the development of new catalysts with controllable product selectivities. Recent attempts to increase the selectivity to C5+ hydrocarbons by preparing catalysts with well-defined active phases or with new supports or by optimizing the interaction between the promoter and the active phase are briefly highlighted. Advances in developing bifunctional catalysts capable of catalyzing both CO hydrogenation to heavier hydrocarbons and hydrocracking/isomerization of heavier hydrocarbons are critically reviewed. It is demonstrated that the control of the secondary hydrocracking reactions by using core-shell nanostructures or solid-acid materials, such as mesoporous zeolites and carbon nanotubes with acid functional groups, is an effective strategy to tune the product selectivity of Fischer-Tropsch synthesis. Very promising selectivities to gasoline- and diesel-range hydrocarbons have been attained over some bifunctional catalysts. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Preparation

    Directory of Open Access Journals (Sweden)

    M.M. Dardir

    2014-03-01

    Full Text Available Some hexanamide-mono and di-linoleniate esters were prepared by the reaction of linolenic acid and hexanamide (derived from the reaction of hexanoic acid and diethanolamine. The chemical structure for the newly prepared hexanamide-mono and di-linoleniate esters were elucidated using elemental analysis, (FTIR, H 1NMR and chemical ionization mass spectra (CI/Ms spectroscopic techniques. The results of the spectroscopic analysis indicated that they were prepared through the right method and they have high purity. The new prepared esters have high biodegradability and lower toxicity (environmentally friendly so they were evaluated as a synthetic-based mud (ester-based mud for oil-well drilling fluids. The evaluation included study of the rheological properties, filtration and thermal properties of the ester based-muds formulated with the newly prepared esters compared to the reference commercial synthetic-based mud.

  1. Synthesis and Characterization of Nanofibrous Polyaniline Thin Film Prepared by Novel Atmospheric Pressure Plasma Polymerization Technique

    Directory of Open Access Journals (Sweden)

    Choon-Sang Park

    2016-01-01

    Full Text Available This work presents a study on the preparation of plasma-polymerized aniline (pPANI nanofibers and nanoparticles by an intense plasma cloud type atmospheric pressure plasma jets (iPC-APPJ device with a single bundle of three glass tubes. The nano size polymer was obtained at a sinusoidal wave with a peak value of 8 kV and a frequency of 26 kHz under ambient air. Discharge currents, photo-sensor amplifier, and optical emission spectrometer (OES techniques were used to analyze the plasma produced from the iPC-APPJ device. Field emission scanning electron microscopy (FE-SEM, transmission electron microscopy (TEM, Fourier transform infrared spectroscopy (FT-IR, gas chromatography-mass spectrometry (GC-MS, and gel permeation chromatography (GPC techniques were used to analyze the pPANI. FE-SEM and TEM results show that pPANI has nanofibers, nanoparticles morphology, and polycrystalline characteristics. The FT-IR and GC-MS analysis show the characteristic polyaniline peaks with evidence that some quinone and benzene rings are broken by the discharge energy. GPC results show that pPANI has high molecular weight (Mw, about 533 kDa with 1.9 polydispersity index (PDI. This study contributes to a better understanding on the novel growth process and synthesis of uniform polyaniline nanofibers and nanoparticles with high molecular weights using the simple atmospheric pressure plasma polymerization technique.

  2. Platinum-Niobium(V Oxide/Carbon Nanocomposites Prepared By Microwave Synthesis For Ethanol Oxidation

    Directory of Open Access Journals (Sweden)

    Virginija KEPENIENĖ

    2016-05-01

    Full Text Available In the present work, Pt nanoparticles were deposited by means of microwave synthesis on the primary carbon supported Nb2O5 composite which was prepared in two different ways: (A by dispersion of Nb2O5 and carbon with the mass ratio equal to 1:1 in a 2-propanol solution by ultrasonication for 30 min. with further desiccation of the mixture and (B by heating the Nb2O5/C composite obtained according to the procedure (A at 500 °C for 2 h. The transmission electron microscopy was used to determine the shape and the size of catalyst particles. X-ray diffraction and inductively coupled plasma optical emission spectroscopy were employed to characterize the structure and composition of the synthesized catalysts. The electrocatalytic activity of the synthesized catalysts towards the oxidation of ethanol in an alkaline medium was investigated by means of cyclic voltammetry.DOI: http://dx.doi.org/10.5755/j01.ms.22.2.8609

  3. Structural and spectroscopic analyses of europium doped yttrium oxyfluoride powders prepared by combustion synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Rakov, Nikifor [PG-Ciência dos Materiais, Universidade Federal do Vale do São Francisco, 48902-300 Juazeiro, BA (Brazil); Guimarães, R. B.; Maciel, Glauco S. [Instituto de Física, Universidade Federal Fluminense, 24210-346 Niterói, RJ (Brazil); Lozano B, W. [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil)

    2013-07-28

    A facile widely spread technique employed to produce low-cost high-yield oxide powders, combustion synthesis, was used to prepare yttrium oxyfluoride crystalline ceramic powders. The structure of the powders was analyzed by X-ray powder diffraction and Rietveld refinement. Samples heat treated at 700 °C had a predominance of vernier orthorhombic Y{sub 6}O{sub 5}F{sub 8} phase, while samples heat treated at 800 °C crystallized in stoichiometric rhombohedral YOF phase. The samples were doped with luminescent europium trivalent ions (Eu{sup 3+}) in different concentrations (1–15 wt.%) and Judd-Ofelt theory was used to probe the distortion from the inversion symmetry of the local crystal field and the degree of covalency between the rare-earth ion and the surrounding ligands. The luminescence lifetime was measured and the luminescence quantum efficiency (LQE) was estimated. We observed that Eu{sup 3+}:Y{sub 6}O{sub 5}F{sub 8} samples presented higher LQE in spite of the larger local crystal field anisotropy found for Eu{sup 3+}:YOF samples.

  4. Ultrasonic assisted preparation of lanthanide-oleate complexes for the synthesis of multifunctional monodisperse upconversion nanoparticles for multimodal imaging.

    Science.gov (United States)

    Tang, Shu-Hua; Wang, Jianing; Yang, Cheng-Xiong; Dong, Lu-Xi; Kong, Deling; Yan, Xiu-Ping

    2014-07-21

    The synthesis of multifunctional monodisperse upconversion nanoparticles (UCNPs) of high quality is highly desired for bioimaging. Lanthanide-oleate complexes are excellent precursors for the synthesis of high quality UCNPs with controllable size and shape. In this work, lanthanide-oleate complexes were prepared by an ultrasonic assisted procedure, and used as precursors for further synthesis of multifunctional monodisperse NaYF4:59%Yb(3+),0.5% Tm(3+)@NaYF₄:20%Gd(3+) nanoparticles without the need for further purification. Heavy doping of Yb(3+) in the core and incorporation of Gd(3+) in the shell made the UCNPs promising for upconversion luminescence (UCL), magnetic resonance (MR) and computed tomography (CT) multimodal imaging. The nanoparticles were further functionalized with bombesin peptide for in vivo UCL/MR/CT imaging of prostate tumors.

  5. Identification, design and synthesis of oxygenated hydrocarbon-based carbon dioxide-soluble polymers for chemical and petroleum engineering applications

    Science.gov (United States)

    Hong, Lei

    Over the past two decades the use of sub/supercritical CO2 has received much attention as a green alternative to organic solvents for chemical processes because of its pressure-tunable physicochemical properties and economic advantages. However the advantages are diminished because of a relative narrow range of CO2-soluble materials. The goal of this work is to identify, design and synthesize oxygenated hydrocarbon-based CO 2-soluble polymers that are able to serve as construction blocks for copolymers, dispersants, surfactants, and thickeners. Without concerning on the cost and the environmental persistence like fluorinated materials, the inexpensive and environmentally benign materials would significantly enhance the viability of sub/supercritical CO2-based technology. Based on both experimental heuristics and ab initio simulation of molecular modeling (performed by Dr. Johnson's group), we proposed specific new polymer structures: poly (3-acetoxy oxetane) (PAO), poly (vinyl methoxymethyl ether) (PVMME), poly (vinyl 1-methoxyethyl ether) (PVMEE), and cellulose triacetate (CTA) oligomers. Phase behavior studies were also performed with novel CO 2-philic compounds containing vinyl acetate, propylene glycol, or multiple tert-butyl groups. PAO, PVMME and PVMME were soluble in CO2, but not as soluble as poly (vinyl acetate). Oligomers of cellulose triacetate with as many as four repeat units solubilized into dense CO2 less than 14 MPa in the concentration range of 1-5 wt%. Phase behaviors of more than twenty compounds in dense CO2 were studied in this project. A new type of phase behavior for solid CO2-philes that melt and dissolve in CO 2 was detailed using a model binary mixture of beta-D-maltose octaacetate and CO2. Copolymers of tetrafluoroethylene (TFE) and vinyl acetate (VAc) exhibited lower miscibility pressures than either of the homopolymers, probably due to quadradentate binding configurations with CO 2. Phase behavior investigation of poly (propylene glycol

  6. Study of structural and catalytic properties of Ni catalysts prepared from inorganic complex precursor for Fischer-Tropsch synthesis

    Science.gov (United States)

    Saheli, Sania; Rezvani, Ali Reza; Malekzadeh, Azim

    2017-09-01

    The silica- and alumina- supported Ni catalysts synthesized by thermal decomposition of inorganic precursors were evaluated for Fischer-Tropsch synthesis (FTS); the structural properties and performance of the catalysts were compared to those of samples constructed via impregnation method. The results revealed that the synthesized catalysts have higher catalytic activity comparison to those prepared via the conventional impregnation method. The effect of the preparation method on the structural properties shows that synthesizing the catalyst through inorganic precursor route is more appropriate. Characterization of catalysts is carried out using inductively coupled plasma (ICP), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and BET specific surface area.

  7. Preparation of Mgo-ceo2 Mixed Oxide with Ionic Liquid as Catalyst for Dimethyl Carbonate Synthesis Via Transesterification

    OpenAIRE

    Abimanyu, Haznan; Sang Yoo, Kye; Ahn, Byoung-Sung

    2010-01-01

    The synthesis and application of dimethyl carbonate (DMC) are achieving increasing importance due to its low toxicity and versatile reactivity. The phosgenation-route has been losing attraction recently due to the use of virulent phosgene. In transesterification process, DMC is co-generated with ethylene glycol (EG). In this study, various ionic liquids were used as template in coprecipitation methods to prepare mesoporous MgO-CeO2 mixed oxides particles. Among the ionic liquids, [Bmim][BF6] ...

  8. Synthesis and sintering of nano-sized forsterite prepared by short mechanochemical activation process

    Energy Technology Data Exchange (ETDEWEB)

    Abdi Maghsoudlou, Mohammad Sadegh, E-mail: msabdim@gmail.com [Materials and Metallurgical Department, Engineering Faculty, Malayer University, Malayer (Iran, Islamic Republic of); Ebadzadeh, Touradj [Ceramic Division, Materials and Energy Research Centre, Alborz (Iran, Islamic Republic of); Sharafi, Zahra; Arabi, Marziyeh; Zahabi, Karim Rostami [Materials and Metallurgical Department, Engineering Faculty, Malayer University, Malayer (Iran, Islamic Republic of)

    2016-09-05

    The findings reported in this paper offer an affordable technique for the synthesis of nano-sized pure forsterite from magnesium chloride hexahydrate, sodium metasilicate nonahydrate and sodium hydroxide as precursors. The stoichiometric mixture of reagents was manually mixed and subjected to high-energy ball milling for a short time (∼10 min). The monitoring of as-milled powder by x-ray diffraction method confirmed that the solid-state displacement reactions occur during high-energy ball milling. After washing and drying, the resulting precursor was subjected to heat treatments in air at various temperatures ranging from 500 to 1100 °C for studying forsterite development. The heat-treated powders were characterized by XRD, STA, FTIR, BET, FE-SEM and TEM techniques. The results revealed that the hydrated compounds formed at room-temperature completely dissociate into periclase and forsterite from 600 °C. The more forsterite phase was generated by the increase of temperature from 600 to 800 °C by the consumption of periclase and amorphous silica present in precursor and finally single-phase forsterite was yielded at 900 °C/2 h. The TEM and FE-SEM results demonstrated that the as-prepared powder consists of separate particles with nearly spherical morphology, 20–60 nm mean particle size and 15.4 m{sup 2}/g specific surface area. Sample sintered at 1500 °C/2 h had 89.5% theoretical density and homogeneous single-phase microstructure. - Highlights: • New reagent compounds were introduced for mechanochemical synthesis of nano-forsterite. • A short mechanochemical method was suggested for the production of Mg{sub 2}SiO{sub 4.} • The single phase powder was found to consist mainly of particles smaller than 60 nm. • Nano-forsterite powder with nearly spherical morphology sintered to 89.5% theoretical density. • A homogeneous single-phase microstructure was produced by sintering sample at 1500 °C/2 h.

  9. Iron catalyst for preparation of polymethylene from synthesis gas and method for producing the catalyst

    Science.gov (United States)

    Sapienza, R.S.; Slegeir, W.A.

    1990-05-15

    This invention relates to a process for synthesizing hydrocarbons; more particularly, the invention relates to a process for synthesizing long-chain hydrocarbons known as polymethylene from carbon monoxide and hydrogen or from carbon monoxide and water or mixtures thereof in the presence of a catalyst comprising iron and platinum or palladium or mixtures thereof which may be supported on a solid material, preferably an inorganic refractory oxide. This process may be used to convert a carbon monoxide containing gas to a product which could substitute for high density polyethylene.

  10. Solution-phase preparation of a 560-compound library of individual pure mappicine analogues by fluorous mixture synthesis.

    Science.gov (United States)

    Zhang, Wei; Luo, Zhiyong; Chen, Christine Hiu-Tung; Curran, Dennis P

    2002-09-04

    Solution-phase mixture synthesis has efficiency advantages and favorable reaction kinetics. Applications of this technique, however, have been discouraged by the difficulty in obtaining individual, pure final products by using conventional separation and identification processes. Introduced here is a new strategy for mixture synthesis that addresses the separation and identification problems. Members of a series of organic substrates are paired with a series of fluorous tags of different chain lengths. The tagged starting materials are then mixed and taken through a multistep reaction process. Fluorous chromatography is used to demix the tagged product mixtures on the basis of the fluorine content of the tags to provide the individual pure components of the mixture, which are detagged to release the final products. The utility of fluorous mixture synthesis is demonstrated by the preparation of a 560-membered library of analogues of the natural product mappicine. A seven-component mixture is carried through a four-step mixture synthesis (two one-pot and two parallel steps) to incorporate two additional points of diversity onto the tetracyclic core. Methods for analysis and purification of the intermediates are established for the quality control of the mixture synthesis.

  11. Role of fuel/oxidizer ratio on the synthesis conditions of Cu–Al{sub 2}O{sub 3} nanocomposite prepared through solution combustion synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Nasiri, H., E-mail: h.nasiri85@yahoo.com [Department of Material Science and Engineering, Faculty of Engineering, Ferdowsi University of Mashhad, P.O. Box: 91775-1111, Mashhad (Iran, Islamic Republic of); Bahrami Motlagh, E.; Vahdati Khaki, J.; Zebarjad, S.M. [Department of Material Science and Engineering, Faculty of Engineering, Ferdowsi University of Mashhad, P.O. Box: 91775-1111, Mashhad (Iran, Islamic Republic of)

    2012-11-15

    Highlights: ► With increasing the fuel to oxidizer ratio synthesis products changed from CuO to Cu{sub 2}O. ► With increasing the fuel to oxidizer ratio the combustion temperature decreased. ► Maximum ratio that synthesis could occur was achieved. ► The stoichiometric ratio had the maximum combustion temperature. ► Solution with graphite had lower combustion temperature. -- Abstract: The role of fuel/oxidizer ratio in the synthesis conditions of Cu–Al{sub 2}O{sub 3} nanocomposite, which was prepared through solution combustion synthesis, method was investigated. For this purpose, copper and aluminum nitrates as well as urea were used as oxidizer and fuel, respectively. The fuel/oxidizer (F/O) ratios were selected from the range of 0.9–1.75. The products were analyzed using X-ray diffraction, SEM and TEM techniques. During the process the temperature was recorded as a function of time. The results showed that by increasing the F/O ratio up to the stoichiometric amount, the combustion temperature increases. Further increment of F/O ratio resulted in a decrease in the combustion temperature. Microscopic evaluations, using SEM and TEM, proved feasibility of the production of Cu–Al{sub 2}O{sub 3} through this method.

  12. Dietary risk evaluation for 28 polycyclic aromatic hydrocarbons (PAHs) in tea preparations made of teas available on the Polish retail market.

    Science.gov (United States)

    Roszko, Marek; Kamińska, Marta; Szymczyk, Krystyna; Jędrzejczak, Renata

    2018-01-02

    The aim of this work was to assess dietary risk resulting from consumption of polycyclic aromatic hydrocarbons (PAHs) with tea infusions. To this end, levels of 28 PAHs in black, green, red and white teas available on the Polish retail market have been assessed. Profiles and correlation between concentrations of individual PAHs have been identified. A model study on transfer of PAHs from tea leaves into tea preparations has been conducted. Relatively high concentrations of 28 evaluated PAHs have been found in 58 tested samples of black, green, red and white teas sampled on the Polish retail market. Total concentration ∑28PAH ranged from 57 to 696 µg kg -1 with mean 258 µg kg -1 (dry tea leaves). The most mature tea leaves fermented to a small degree contained relatively the highest PAH levels among all four tested tea types. Relatively low PAH transfer rates into tea infusions and limited volumes of the consumed tea keep the risks associated with PAH dietary intake at a safely low level. The worst-case scenario dietary intake values were 7.62/0.82/0.097 ng kg -1 b.w. day -1 (estimated on the basis of the maximum found concentrations 696/113/23 µg kg -1 and maximum observed transfer rates 24/16/9%) for ∑28PAH/∑PAH4/B[a]P, respectively. MOE values calculated using the above worst case estimates exceeded 700,000 and 400,000 (BMDL 10 0.07 and 0.34 mg kg -1 b.w. day -1 ) for B[a]P and PAH4, respectively. Both B[a]P and PAH4 concentrations may be used as indicators of total PAH concentration in tea leaves; PAH4 slightly better fits low molecular weight PAHs. Several correlations between various PAHs/groups of PAHs have been identified, the strongest one (R 2 = 0.92) between PAH4 and EU PAH 15+1.

  13. Synthesis and characterization of mangenese(III) porphyrin supported on imidazole modified chloromethylated MIL-101(Cr): A heterogeneous and reusable catalyst for oxidation of hydrocarbons with sodium periodate

    Energy Technology Data Exchange (ETDEWEB)

    Zadehahmadi, Farnaz; Tangestaninejad, Shahram, E-mail: stanges@sci.ui.ac.ir; Moghadam, Majid, E-mail: moghadamm@sci.ui.ac.ir; Mirkhani, Valiollah, E-mail: mirkhani@sci.ui.ac.ir; Mohammadpoor-Baltork, Iraj; Khosropour, Ahmad R.; Kardanpour, Reihaneh

    2014-10-15

    In the present work, chloromethylated MIL-101(Cr) modified with imidazole, Im-MIL-101, was applied as a support for immobilizing of tetraphenylporphyrinatomangenese(III) chloride. The imidazole-bound MIL-101, Im-MIL-101, not only used as support for immobilization of manganese porphyrin but also applied as a heterogeneous axial base. The Mn(TPP)Cl@Im-MIL-101 catalyst was characterized by UV–vis, FT-IR, X-ray diffraction (XRD), N{sub 2} adsorption, field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX), elemental analysis and inductively coupled plasma (ICP) methods. The catalytic activity of this new catalytic system was investigated in the alkene epoxidation and alkane hydroxylation using NaIO{sub 4} as an oxidant in CH{sub 3}CN/H{sub 2}O at room temperature. This heterogeneous catalyst is highly efficient, stable and reusable in the oxidation of hydrocarbons. - Highlights: • MIL-101 was modified by covalent post synthetic modification. • Mn(TPP)Cl was anchored to imidazole modified MIL-101 by covalent attachment. • A heterogeneous catalyst was prepared. • The catalyst was used for epoxidation of alkenes and hydroxylation of alkanes. • The catalyst was reusable.

  14. Facile synthesis of magnetic carbon nitride nanosheets and its application in magnetic solid phase extraction for polycyclic aromatic hydrocarbons in edible oil samples.

    Science.gov (United States)

    Zheng, Hao-Bo; Ding, Jun; Zheng, Shu-Jian; Zhu, Gang-Tian; Yuan, Bi-Feng; Feng, Yu-Qi

    2016-01-01

    In this study, we proposed a method to fabricate magnetic carbon nitride (CN) nanosheets by simple physical blending. Low-cost CN nanosheets prepared by urea possessed a highly π-conjugated structure; therefore the obtained composites were employed as magnetic solid-phase extraction (MSPE) sorbent for extraction of polycyclic aromatic hydrocarbons (PAHs) in edible oil samples. Moreover, sample pre-treatment time could be carried out within 10 min. Thus, a simple and cheap method for the analysis of PAHs in edible oil samples was established by coupling magnetic CN nanosheets-based MSPE with gas chromatography-mass spectrometry (GC/MS) analysis. Limits of quantitation (LOQs) for eight PAHs ranged from 0.4 to 0.9 ng/g. The intra- and inter-day relative standard deviations (RSDs) were less than 15.0%. The recoveries of PAHs for spiked soybean oil samples ranged from 91.0% to 124.1%, with RSDs of less than 10.2%. Taken together, the proposed method offers a simple and cost-effective option for the convenient analysis of PAHs in oil samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Synthesis, Characterization and Catalytic Activity of Cu/Cu2O Nanoparticles Prepared in Aqueous Medium

    Directory of Open Access Journals (Sweden)

    Sayed M. Badawy

    2015-07-01

    Full Text Available Copper/Copper oxide (Cu/Cu2O nanoparticles were synthesized by modified chemical reduction method in an aqueous medium using hydrazine as reducing agent and copper sulfate pentahydrate as precursor. The Cu/Cu2O nanoparticles were characterized by X-ray Diffraction (XRD, Energy Dispersive X-ray Fluorescence (EDXRF, Scanning Electron Microscope (SEM, and Transmission Electron Microscope (TEM. The analysis revealed the pattern of face-centered cubic (fcc crystal structure of copper Cu metal and cubic cuprites structure for Cu2O. The SEM result showed monodispersed and agglomerated particles with two micron sizes of about 180 nm and 800 nm, respectively. The TEM result showed few single crystal particles of face-centered cubic structures with average particle size about 11-14 nm. The catalytic activity of Cu/Cu2O nanoparticles for the decomposition of hydrogen peroxide was investigated and compared with manganese oxide MnO2. The results showed that the second-order equation provides the best correlation for the catalytic decomposition of H2O2 on Cu/Cu2O. The catalytic activity of hydrogen peroxide by Cu/Cu2O is less than the catalytic activity of MnO2 due to the presence of copper metal Cu with cuprous oxide Cu2O. © 2015 BCREC UNDIP. All rights reservedReceived: 6th January 2015; Revised: 14th March 2015; Accepted: 15th March 2015How to Cite: Badawy, S.M., El-Khashab, R.A., Nayl, A.A. (2015. Synthesis, Characterization and Catalytic Activity of Cu/Cu2O Nanoparticles Prepared in Aqueous Medium. Bulletin of Chemical Reaction Engineering & Catalysis, 10 (2: 169-174. (doi:10.9767/bcrec.10.2.7984.169-174 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.10.2.7984.169-174  

  16. Photocatalytic synthesis of 2-methylquinolines with TiO2 Wackherr and Home Prepared TiO2 – A comparative study

    National Research Council Canada - National Science Library

    Selvam, Kaliyamoorthy; Swaminathan, Meenakshisundaram

    2017-01-01

    A comparative study was carried out on the efficiency of titanium dioxide specimens Wackherr TiO2, prepared TiO2 and Aeroxide P25 toward the photocatalytic synthesis of pharmaceutically important 2-methylquinolines...

  17. The ortho backbone amide linker (o-BAL) is an easily prepared and highly acid-labile handle for solid-phase synthesis

    DEFF Research Database (Denmark)

    Boas, Ulrik; Brask, Jesper; Christensen, J.B.

    2002-01-01

    The tris(alkoxy)benzyl backbone amide linker (BAL) has found widespread application in solid-phase synthesis. The key intermediate for preparation of para BAL (p-BAL) is 2,6-dimethoxy-4-hydroxybenzaldehyde; several reports on its synthesis have appeared. However, the ortho analogue of the handle (o...

  18. Carbon Isotope Characterization of Organic Intermediaries in Hydrothermal Hydrocarbon Synthesis by Pyrolysis-GC-MS-C-IRMS

    Science.gov (United States)

    Socki, Richard A.; Fu, Qi; Niles, Paul B.

    2010-01-01

    We report results of experiments designed to characterize the carbon isotope composition of intermediate organic compounds produced as a result of mineral surface catalyzed reactions. The impetus for this work stems from recently reported detection of methane in the Martian atmosphere coupled with evidence showing extensive water-rock interaction during Martian history. Abiotic formation by Fischer-Tropsch-type (FTT) synthesis during serpentinization reactions may be one possible process responsible for methane generation on Mars, and measurement of carbon and hydrogen isotopes of intermediary organic compounds can help constrain the origin of this methane. Of particular interest within the context of this work is the isotopic composition of organic intermediaries produced on the surfaces of mineral catalysts (i.e. magnetite) during hydrothermal experiments, and the ability to make meaningful and reproducible isotope measurements. Our isotope measurements utilize a unique analytical technique combining Pyrolysis-Gas Chromatograph-Mass Spectrometry-Combustion-Isotope Ratio Mass Specrometry (Py-GC-MS-C-IRMS). Others have conducted similar pyrolysis-IRMS experiments on low molecular weight organic acids (Dias, et al, Organic Geochemistry, 33 [2002]). Our technique differs in that it carries a split of the pyrolyzed GC-separated product to a Thermo DSQ-II quadrupole mass spectrometer as a means of making qualitative and semi-quantitative compositional measurements of the organic compounds. A sample of carboxylic acid (mixture of C1 through C6) was pyrolyzed at 100 XC and passed through the GC-MS-C-IRMS (combusted at 940 XC). In order to test the reliability of our technique we compared the _13C composition of different molecular weight organic acids (from C1 through C6) extracted individually by the traditional sealed-tube cupric oxide combustion (940 XC) method with the _13C produced by our pyrolysis technique. Our data indicate that an average 4.3. +/-0.5. (V

  19. One-Pot Ketone Synthesis with Alkylzinc Halides Prepared from Alkyl Halides via a Single Electron Transfer (SET) Process: New Extension of Fukuyama Ketone Synthesis.

    Science.gov (United States)

    Lee, Jung Hwa; Kishi, Yoshito

    2016-06-08

    One-pot ketone synthesis has been developed with in situ activation of alkyl halides to alkylzinc halides in the presence of thioesters and Pd-catalyst. The new method provides us with a reliable option for a coupling at a late stage in a convergent synthesis of complex molecules, with use of a near 1:1 molar ratio of coupling partners. First, two facile, orthogonal methods have been developed for preparation of alkylzinc halides: (1) direct insertion of zinc dust to 1°- and 2°-alkyl halides in the presence of LiI in DMI and (2) early transition-metal assisted activation of alkyl halides via a single electron transfer (SET) process. CrCl2 has been found as an unprecedented, inevitable mediator for preparation of alkylzinc halides from alkyl halides, where CrCl2 likely functions to trap R·, generated via a SET process, and transfer it to Zn(II) to form RZnX. In addition to a commonly used CoPc, a new radical initiator NbCpCl4 has been discovered through the study. Second, with use of the two orthogonal methods, three sets of coupling conditions have been developed to complete one-pot ketone synthesis, with Condition A (Pd2dba3, PR3, Zn, LiI, TESCl, DMI), Condition B (A + CrCl2), and Condition C (B + NbCpCl4 or CoPc) being useful for simple linear and α-substituted substrates, simple linear and β-substituted substrates, and complex substrates, respectively. Condition C is applicable to the broadest range of substrates. Overall, one-pot ketone synthesis gives excellent yields, with good functional group tolerance. Controlled formation of alkylzinc halides by a combination of CrCl2 and NbCpCl4 or CoPc is crucial for its application to complex substrates. Interestingly, one-pot ketone synthesis does not suffer from the chemical instability due to the inevitable radical pathway(s), for example a 1,5-H shift. Notably, even with the increase in molecular size, no significant decrease in coupling efficiency has been noticed. To illustrate the synthetic value at a late

  20. An automated synthesis module for preparation of L-3-[I-123]iodo-alpha-methyl tyrosine

    NARCIS (Netherlands)

    Luurtsema, G; Jager, PL; Piers, A; de Hooge, MN

    2001-01-01

    L-3-[I-123]iodo-alpha-methyl tyrosine (IMT) is an artificial amino acid suitable for SPECT imaging of various tumours. Manual synthesis of this radiopharmaceutical is reliable, but time-consuming and may require handling of large quantities of radioactivity. We developed an automated IMT synthesis

  1. Preparation of tri(ethylene glycol) grafted core-shell type polymer support for solid-phase peptide synthesis.

    Science.gov (United States)

    Kim, Jaehi; Kim, Seojung; Shin, Dong-Sik; Lee, Yoon-Sik

    2017-12-13

    A core-shell type polymer support for solid-phase peptide synthesis has been developed for high coupling efficiency of peptides and versatile applications such as on-bead bioassays. Although various kinds of polymer supports have been developed, they have their own drawbacks including poor accessibility of reagents and incompatibility in aqueous solution. In this paper, we prepared hydrophilic tri(ethylene glycol) (TEG) grafted core-shell type polymer supports (TEG SURE) for efficient solid-phase peptide synthesis and on-bead bioassays. TEG SURE was prepared by grafting TEG derivative on the surface of AM PS resin via biphasic diffusion control method and subsequent acetylation of amine groups which are located at the core region of AM PS resin. The performance of TEG SURE was evaluated by synthesizing several peptides. Three points can be highlighted: (1) easy control of loading level of TEG, (2) improved efficiency of peptide synthesis compared with the conventional resins, and (3) applicability of on-bead bioassays. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.

  2. Apparatus for hydrocarbon extraction

    Science.gov (United States)

    Bohnert, George W.; Verhulst, Galen G.

    2013-03-19

    Systems and methods for hydrocarbon extraction from hydrocarbon-containing material. Such systems and methods relate to extracting hydrocarbon from hydrocarbon-containing material employing a non-aqueous extractant. Additionally, such systems and methods relate to recovering and reusing non-aqueous extractant employed for extracting hydrocarbon from hydrocarbon-containing material.

  3. Solid-supported reagents for multi-step organic synthesis: preparation and application.

    Science.gov (United States)

    Ley, S V; Baxendale, Ian R; Brusotti, G; Caldarelli, M; Massi, A; Nesi, M

    2002-04-01

    Since the early days of combinatorial chemistry solid-phase organic synthesis has been the method of choice for the production of large libraries. Solution-phase synthesis is again gaining importance especially for the synthesis of parallel arrays of smaller, focussed libraries containing single compounds with high degrees of purity. In the field of solution-phase library generation, the use of solid-supported reagents, catalysts and scavengers is emerging as a leading strategy, combining the advantages of both solid-phase organic synthesis (e.g. allowing the employment of an excess of reagent without the need for additional purification steps) and solution-phase chemistry (e.g. the ease of monitoring the progress of the reactions by applying LC-MS, TLC or standard NMR techniques). An account of some of the most recent advances in this area of research will be presented.

  4. Preparation and characterization of aminobenzyl cellulose by two step synthesis from native cellulose

    Science.gov (United States)

    Synthesis and structural characterizations of nitro- and amino-benzyl cellulose were carried out. Cellulose derivatives were synthesized by etherification. Nitrobenzylation produced 80% yield by treating a mixture of microcrystalline cellulose, 4-dimethyl aminopyridine and 4-nitrobenzyl chloride at ...

  5. Preparing Students for Research: Synthesis of Substituted Chalcones as a Comprehensive Guided-Inquiry Experience

    Science.gov (United States)

    Vyvyan, James R.; Pavia, Donald L.; Lampman, Gary M.; Kriz, George S., Jr.

    2002-09-01

    A guided inquiry experiment involving the synthesis and characterization of substituted benzalacetophenones (chalcones) is described. The chalcones are produced in the aldol condensation of substituted benzaldehydes with substituted acetophenones. Each student is assigned a different target chalcone and conducts online and printed literature searches on the target. After completing the synthesis and purification of their product, the students compare their data with those found in the literature.

  6. Renewable synthesis-gas-production. Do hydrocarbons in the reactant flow of the reverse water-gas shift reaction cause coke formation?

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, A.; Kern, C.; Jess, A. [Bayreuth Univ. (Germany). Dept. of Chemical Engineering

    2013-11-01

    In a two-step synthetic fuel production process based on carbon dioxide and renewable hydrogen, the best possible selectivity towards liquid hydrocarbons (Hc) shall be implemented. The process consists of a combination of the Reverse Water-Gas Shift reaction and the Fischer-Tropsch synthesis. To achieve this goal, gaseous short-chained Hc from the FTS reactor are recycled in the RWGS unit. In this paper, challenges coming up with the implementation of a recycle loop are discussed. First of all, it has to be examined whether Hc are converted under conditions present in the RWGS reactor. The coking caused by the recycle of Hc is regarded, including thermal coking in the heating zone of the reactor and catalytic coking in the catalyst bed. Coking of course is unwanted, as it deactivates the catalyst. The scope of this work is to find out to which extent and under which conditions gaseous Hc can be recycled. Therefore, experiments were carried out in both, a quartz glass reactor using a commercial Ni-catalyst at ambient pressure and in a pressurized steel reactor (without catalyst) to examine coking during the thermal decomposition of Hc. The catalytic experiments at atmospheric pressure showed that a recycle of CH{sub 4} did not cause coking up to a ratio of CH{sub 4}/CO{sub 2} below one. For these conditions, long term stability was proved. The reaction rates of the CH{sub 4} conversion were below those of the RWGS reaction. However, replacing CH{sub 4} by C{sub 3}H{sub 8} leads to thermal and catalytic coking. Catalytic coking hits the maximum level at about 700 C and decreases for higher temperatures and, thus is not regarded as a problem for the RWGS reactor. In contrast to that, thermal coking raises with higher temperatures, but it can be supressed efficiently with additional injection of H{sub 2}O, which of course shifts the equilibrium towards the undesired reactant side. (orig.)

  7. Preparation of chitosan nanoparticles from shrimp shells and investigation of its catalytic effect in diastereoselective synthesis of dihydropyrroles.

    Science.gov (United States)

    Zahedi, Safura; Safaei Ghomi, Javad; Shahbazi-Alavi, Hossein

    2018-01-01

    Preparation of chitosan nanoparticles (CS-NPs) was examined from shrimp shells for their catalytic activity. The yield of crude chitosan was 87.8%. The structure of chitosan nanoparticles was determined by FT-IR, SEM and XRD analysis. Then, diastereoselective synthesis of dihydropyrroles was done using chitosan nanoparticles in water under ultrasonic irradiation. This polymeric nanocatalyst could be used instead of the old toxic commercial organic basic catalysts and could be readily isolated from the reaction mixture and recycled several times without significant loss of catalytic activity. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Synthesis and Characterization of a Novel Polyacetal & Design and Preparation of Superhydrophobic Photocatalytic Surfaces

    Science.gov (United States)

    Zhao, Yuanyuan

    Acetal copolymers represent a family of well-established engineering thermoplastics serving a broad range of important industrial applications including replacement for metals. The first part of this thesis describes the first synthesis of an eight-member ring acetal, 6-methyl-1, 3-dioxocane (MDOC), and its cationic copolymerization with trioxane initiated by boron trifluoride dibutyl etherate. The copolymerization process was monitored in situ using proton NMR. Incorporation of MDOC led to the insertion of the "stopper" unit, "--[CH2CH2CH(CH3)CH 2CH2)O]--", thus synthesizing the new acetal copolymer. A superior copolymer thermal stability with a ~ 20oC increase in degradation onset temperature compared with end-capped polyoxmethylene was observed. Both TGA and DSC data indicated the random placement of the "stopper" in the copolymer likely due to efficient transacetalization because of the higher basicity and flexibility of the stopper unit compared with co-units comprising 2 to 4 carbons in length. DSC thermo-grams showed a melting curve of a polymer with melting point lower, as expected, than that of oxymethylene homopolymer. No homopolymer in the copolymer samples was in indicated by TGA. The new acetal copolymer, poly(6-methyl-1,3-dioxocane-co-trioxane), which has a "stopper" co-unit with five carbon atoms along the backbone, contains the longest reported stopper co-unit, potentially leading to improved elongation, and toughness and better compatibility with a range of additives compared to acetal homopolymers.. Chapter 3 presents a novel lamination fabrication method that enables pre-formed TiO2 nanoparticles to become partially embedded in the surface of a thermoplastic polymer film. In this way, the particles are strongly adhered to the surface while remaining accessible to the aqueous solution. By modifying the fabrication conditions (e.g. temperature, pressure, polymer melt viscosity, etc.), the morphology of the hierarchical TiO2-polymer surface can be

  9. Laser-induced particle size tuning and structural transformations in germanium nanoparticles prepared by stain etching and colloidal synthesis route

    Energy Technology Data Exchange (ETDEWEB)

    Karatutlu, Ali, E-mail: a.karatutlu@qmul.ac.uk, E-mail: ali.karatutlu@bou.edu.tr [Centre for Condensed Matter and Materials Physics, School of Physics and Astronomy, Queen Mary, University of London, London E1 4NS (United Kingdom); Electrical and Electronics Engineering, Bursa Orhangazi University, 16310 Yıldırım/Bursa (Turkey); Little, William; Ersoy, Osman; Zhang, Yuanpeng; Sapelkin, Andrei [Centre for Condensed Matter and Materials Physics, School of Physics and Astronomy, Queen Mary, University of London, London E1 4NS (United Kingdom); Seker, Isa [Bio-Nanotechnology Research and Development Centre, Fatih University, 34500 Buyukcekmece, Istanbul (Turkey)

    2015-12-28

    In this study, with the aid of Raman measurements, we have observed transformations in small (∼3 nm and ∼10 nm) free-standing Ge nanoparticles under laser light exposure. The nanoparticles were obtained by the chemical stain etching of a monocrystalline Ge wafer and of Ge powder and by colloidal synthesis route. We found that the transformation path depends on laser power and exposure time. At relatively low values of the laser power (2 mW) over a period of 100 min, the Raman signal indicates transformation of the sample from a nanocrystaline to bulk-like state, followed by partial oxidation and finally a conversion of the entire sample into alpha-quartz type GeO{sub 2}. However, when the laser power is set at 60 mW, we observed a heat release during an explosive crystallization of the nanocrystalline material into bulk Ge without noticeable signs of oxidation. Together with the transmission electron microscopy measurements, these results suggest that the chemical stain etching method for the preparation of porous Ge may not be a top-down process as has been widely considered, but a bottom up one. Systematic studies of the laser exposure on Ge nanoparticles prepared by colloidal synthesis results in the fact that the explosive crystallisation is common for H-terminated and partially disordered Ge nanoparticles regardless of its particle size. We suggest possible bio-medical applications for the observed phenomena.

  10. A novel S-sulfhydrated human serum albumin preparation suppresses melanin synthesis

    Directory of Open Access Journals (Sweden)

    Mayumi Ikeda

    2018-04-01

    Full Text Available Products of ultraviolet (UV irradiation such as reactive oxygen species (ROS and nitric oxide (NO stimulate melanin synthesis. Reactive sulfur species (RSS have been shown to have strong ROS and NO scavenging effects. However, the instability and low retention of RSS limit their use as inhibitors of melanin synthesis. The free thiol at Cys34 on human serum albumin (HSA is highly stable, has a long retention and possess a high reactivity for RSS. We report herein on the development of an HSA based RSS delivery system. Sulfane sulfur derivatives released from sodium polysulfides (Na2Sn react readily with HSA. An assay for estimating the elimination of sulfide from polysulfide showed that almost all of the sulfur released from Na2Sn bound to HSA. The Na2Sn-treated HSA was found to efficiently scavenge ROS and NO produced from chemical reagents. The Na2Sn-treated HSA was also found to inhibit melanin synthesis in B16 melanoma cells and this inhibition was independent of the number of added sulfur atoms. In B16 melanoma cells, the Na2Sn-treated HSA also inhibited the levels of ROS and NO induced by UV radiation. Finally, the Na2Sn-treated HSA inhibited melanin synthesis from L-DOPA and mushroom tyrosinase and suppressed the extent of aggregation of melanin pigments. These data suggest that Na2Sn-treated HSA inhibits tyrosinase activity for melanin synthesis via two pathways; by directly inhibiting ROS signaling and by scavenging NO. These findings indicate that Na2Sn-treated HSA has potential to be an attractive and effective candidate for use as a skin whitening agent. Keywords: Ultraviolet irradiation, Human serum albumin, Reactive sulfur species, Whitening agent, Oxidative stress

  11. A novel S-sulfhydrated human serum albumin preparation suppresses melanin synthesis.

    Science.gov (United States)

    Ikeda, Mayumi; Ishima, Yu; Kinoshita, Ryo; Chuang, Victor T G; Tasaka, Nanami; Matsuo, Nana; Watanabe, Hiroshi; Shimizu, Taro; Ishida, Tatsuhiro; Otagiri, Masaki; Maruyama, Toru

    2018-04-01

    Products of ultraviolet (UV) irradiation such as reactive oxygen species (ROS) and nitric oxide (NO) stimulate melanin synthesis. Reactive sulfur species (RSS) have been shown to have strong ROS and NO scavenging effects. However, the instability and low retention of RSS limit their use as inhibitors of melanin synthesis. The free thiol at Cys34 on human serum albumin (HSA) is highly stable, has a long retention and possess a high reactivity for RSS. We report herein on the development of an HSA based RSS delivery system. Sulfane sulfur derivatives released from sodium polysulfides (Na 2 S n ) react readily with HSA. An assay for estimating the elimination of sulfide from polysulfide showed that almost all of the sulfur released from Na 2 S n bound to HSA. The Na 2 S n -treated HSA was found to efficiently scavenge ROS and NO produced from chemical reagents. The Na 2 S n -treated HSA was also found to inhibit melanin synthesis in B16 melanoma cells and this inhibition was independent of the number of added sulfur atoms. In B16 melanoma cells, the Na 2 S n -treated HSA also inhibited the levels of ROS and NO induced by UV radiation. Finally, the Na 2 S n -treated HSA inhibited melanin synthesis from L-DOPA and mushroom tyrosinase and suppressed the extent of aggregation of melanin pigments. These data suggest that Na 2 S n -treated HSA inhibits tyrosinase activity for melanin synthesis via two pathways; by directly inhibiting ROS signaling and by scavenging NO. These findings indicate that Na 2 S n -treated HSA has potential to be an attractive and effective candidate for use as a skin whitening agent. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  12. Size-Controlled Synthesis of Nano-Zeolites and Their Application to Light Olefin Synthesis

    OpenAIRE

    Tago, Teruoki; Konno, Hiroki; Nakasaka, Yuta; Masuda, Takao

    2012-01-01

    For the application of zeolites as heterogeneous catalysts, low diffusion resistance for hydrocarbons within the micropore is essential for improving product selectivity and catalyst lifetime. This problem has been overcome by reducing the crystal size. This review introduces size-controlled preparation of nano-sized zeolites via hydrothermal synthesis in water/surfactant/organic solvent (emulsion method) and their application to heterogeneous catalysts. The ionicity of the hydrophilic group ...

  13. β-Cyclodextrin for design of alumina supported cobalt catalysts efficient in Fischer-Tropsch synthesis.

    Science.gov (United States)

    Jean-Marie, Alan; Griboval-Constant, Anne; Khodakov, Andrei Y; Monflier, Eric; Diehl, Fabrice

    2011-10-14

    Addition of β-cyclodextrin during catalyst preparation strongly affects the structure and catalytic performance of alumina supported cobalt catalysts for Fischer-Tropsch synthesis. Impregnation of the support with solutions containing β-cyclodextrin leads to higher metal dispersion and spectacularly enhances both reaction rate and heavy hydrocarbons productivity in Fischer-Tropsch synthesis. This journal is © The Royal Society of Chemistry 2011

  14. Synthesis and Solution Properties of Adamantane Containing Quaternary Ammonium Salt-type Cationic Surfactants: Hydrocarbon-based, Fluorocarbonbased and Bola-type.

    Science.gov (United States)

    Yoshimura, Tomokazu; Okada, Mari; Matsuoka, Keisuke

    2016-10-01

    Quaternary ammonium salt-type cationic surfactants with an adamantyl group (hydrocarbon-type; CnAdAB, fluorocarbon-type; Cm(F)C3AdAB, bola-type; Ad-s-Ad, where n, m and s represent hydrocarbon chain lengths of 8-16, fluorocarbon chain lengths of 4-8, and spacer chain length of 10-12) were synthesized via quaternization of N, N-dimethylaminoadamantane and n-alkyl bromide or 1, n-dibromoalkane. Conductivity and surface tension were measured to characterize the solution properties of the synthesized adamantyl group-containing cationic surfactants. In addition, the effects of hydrocarbon and fluorocarbon chain lengths and spacer chain length between headgroups on the measured properties were evaluated by comparison with those of conventional cationic surfactants. The critical micelle concentration (CMC) of CnAdAB and Ad-s-Ad was 2/5 of that for the corresponding conventional surfactants CnTAB and bola-type surfactants with similar number of carbons in the alkyl or alkylene chain; this was because of the increased hydrophobicity due to the adamantyl group. A linear relationship between the logarithm of CMC and the hydrocarbon chain length for CnAdAB was observed, as well as for CnTAB. The slope of the linear correlation for both surfactants was almost the same, indicating that the adamantyl group does not affect the CMC with variations in the hydrocarbon chain length. Similar to conventional surfactants CnTAB, the hydrocarbon-type CnAdAB is highly efficient in reducing the surface tension of water, despite the large occupied area per molecule resulting from the relatively bulky structure of the adamantane skeleton. On the other hand, the bola-type Ad-s-Ad resulted in increased surface tension compared to CnAdAB, indicating that the curved chain between adamantyl groups leads to poor adsorption and orientation at the air-water interface.

  15. Electron-microscopic observation of BaTiO3 prepared by additive assisted aqueous synthesis

    OpenAIRE

    Maxim, F.; Ferreira, P.; Vilarinho, P M; Aimable, A.; Bowen, P.

    2017-01-01

    Bulk barium titanate (BaTiO3) has found widespread applications especially in multi-layered ceramic capacitors (MLCCs) and embedded decoupling capacitors (EDC). In the last years, the interest in one-dimensional (1D) nanostructured ferroelectric systems (nanotubes, nanowires, nanorods, nanobelts, nanofibers) is increasing. Recently theoretical studies reported an enhancement of ferroelectricity in 1D systems. Although the hydrothermal and aqueous synthesis of equiaxed barium titanate powders ...

  16. Formation of hydrocarbons by bacteria and algae

    Energy Technology Data Exchange (ETDEWEB)

    Tornabene, T.G.

    1980-12-01

    A literature review has been performed summarizing studies on hydrocarbon synthesis by microorganisms. Certain algal and bacterial species produce hydrocarbons in large quantities, 70 to 80% of dry cell mass, when in a controlled environment. The nutritional requirements of these organisms are simple: CO/sub 2/ and mineral salts. The studies were initiated to determine whether or not microorganisms played a role in petroleum formation. 90 references. (DMC)

  17. Photocatalytic activity and RNO dye degradation of nitrogen-doped TiO{sub 2} prepared by ionothermal synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Pipi, Angelo; Ruotolo, Luis, E-mail: pluis@ufscar.br [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Engenharia Quimica; Byzynski, Gabriela [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Araraquara, SP (Brazil)

    2017-05-15

    This work concerns the preparation a nitrogen-doped TiO{sub 2} by ionothermal synthesis methods and the photocatalytic studies. In this procedure, alkoxide was used as a titanium source, and a deep eutectic mixture of choline chloride and urea (molar ratio 1:2) served as a solvent and source of nitrogen. Different samples were synthesized varying the percentages of the eutectic mixture, titanium butoxide, and water, as well as temperature and reaction time. The catalysts were characterized by X-ray diffraction, Raman spectrometry, scanning electron microscopy, and diffuse reflectance spectroscopy. N-doping was confirmed by X-ray photoelectron spectroscopy. The photocatalytic activity of the N-TiO{sub 2} nanoparticles was evaluated in the oxidation of N,N-dimethyl-4-nitrosoaniline (RNO) dye. The best photocatalytic activity under illumination by UV and visible light was found for the catalysts prepared under reflux in the presence of water, and for the catalysts prepared hydrothermally using intermediate percentages of the nitrogen source (the eutectic mixture). (author)

  18. Influence of oxalate ligand functionalization on Co/ZSM-5 activity in Fischer Tropsch synthesis and hydrodeoxygenation of oleic acid into hydrocarbon fuels.

    Science.gov (United States)

    Ayodele, Olumide Bolarinwa

    2017-08-30

    Achieving high degree of active metal dispersions at the highest possible metal loading and high reducibility of the metal remains a challenge in Fischer Tropsch synthesis (FTS) as well as in hydrogeoxygenation (HDO).This study therefore reports the influence of oxalic acid (OxA) functionalization on the metal dispersion, reducibility and activity of Co supported ZSM-5 catalyst in FTS and HDO of oleic acid into paraffin biofuel. The Brunauer-Emmett-Teller (BET) results showed that cobalt oxalate supported ZSM-5 catalyst (CoOx/ZSM-5) synthesized from the incorporation of freshly prepared cobalt oxalate complex into ZSM-5 displayed increase in surface area, pore volume and average pore size while the nonfunctionalized cobalt supported on ZSM-5 (Co/ZSM-5) catalyst showed reduction in those properties. Furthermore, both XRD and XPS confirmed the presence of Co° formed from the decomposition of CoOx during calcination of CoOx/ZSM-5 under inert atmosphere. The HRTEM showed that Co species average particle sizes were smaller in CoOx/ZSM-5 than in Co/ZSM-5, and in addition, CoOx/ZSM-5 shows a clear higher degree of active metal dispersion. The FTS result showed that at CO conversion over Co/ZSM-5 and CoOx/ZSM-5 catalysts were 74.28% and 94.23% and their selectivity to C5+ HC production were 63.15% and 75.4%, respectively at 4 h TOS. The HDO result also showed that the CoOx/ZSM-5 has higher OA conversion of 92% compared to 59% over Co/ZSM-5. In addition CoOx/ZSM-5 showed higher HDO and isomerization activities compared to Co/ZSM-5.

  19. Synthesis and characterization of a molecularly imprinted polymer for the isolation of the 16 US-EPA priority polycyclic aromatic hydrocarbons (PAHs) in solution.

    Science.gov (United States)

    Ncube, Somandla; Kunene, Phumlile; Tavengwa, Nikita T; Tutu, Hlanganani; Richards, Heidi; Cukrowska, Ewa; Chimuka, Luke

    2017-09-01

    A smart sorbent consisting of benzo[k]fluoranthene-imprinted and indeno[1 2 3-cd]pyrene-imprinted polymers mixed at 1:1 (w/w) was successfully screened from several cavity-tuning experiments and used in the isolation of polycyclic aromatic hydrocarbons from spiked solution. The polymer mixture showed high cross selectivity and affinity towards all the 16 US-EPA priority polycyclic aromatic hydrocarbons. The average extraction efficiency from a cyclohexane solution was 65 ± 13.3% (n = 16, SD). Batch adsorption and kinetic studies confirmed that the binding of polycyclic aromatic hydrocarbons onto the polymer particles resulted in formation of a monolayer and that the binding process was the rate limiting step. The imprinted polymer performance studies confirmed that the synthesized polymer had an imprinting efficiency of 103.9 ± 3.91% (n = 3, SD). A comparison of the theoretical number of cavities and the experimental binding capacity showed that the overall extent of occupation of the imprinted cavities in the presence of excess polycyclic aromatic hydrocarbons was 128 ± 6.45% (n = 3, SD). The loss of selectivity was estimated at 2.9% with every elution cycle indicating that the polymer can be re-used several times with limited loss of selectivity and sensitivity. The polymer combination has shown to be an effective adsorbent that can be used to isolate all the 16 US-EPA priority polycyclic aromatic hydrocarbons in solution. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Luminescent Properties of Y2O3:Eu3+ Nanocrystals Prepared by Molten Salt Synthesis

    Directory of Open Access Journals (Sweden)

    Lijun Luo

    2013-01-01

    Full Text Available A series of red phosphors Y2O3:Eu3+ were prepared by the molten salt method with different surfactants. Their structures, morphologies, and the photoluminescent properties were investigated at room temperature. The particles size of Y2O3:Eu3+ can be controlled by adjusting the kinds of surfactants. The phosphor Y2O3:Eu3+ prepared with NP-10 [polyoxyethylene (10 nonyl phenyl ether] shows regular morphology and higher crystallinity, and its average particle size is about 200 nm. Bright red light can be observed by naked eyes from the red phosphor under 254 nm excitation.

  1. Synthesis and characterization of laurate-intercalated Mg–Al layered double hydroxide prepared by coprecipitation

    DEFF Research Database (Denmark)

    Gerds, Nathalie Christiane; Katiyar, Vimal; Koch, Christian Bender

    2012-01-01

    Effective utilization of layered double hydroxides (LDH) for industrial applications requires the synthesis of pure and well-defined LDH phases. In the present study, dodecanoate (laurate) anions were intercalated into Mg–Al-layered double hydroxide (LDH-C12) by coprecipitation in the presence...... intercalated structure, but we here demonstrate it to be magnesium laurate (Mg-C12). The LDH-C12 compound showed high structural order with a basal spacing of 2.41nm. Fourier-transform IR-spectra confirmed the intercalation of the laurate anions in the interlayer. Transmission electron microscopy showed plate...

  2. Gas sensing with nano-indium oxides (In2O3) prepared via continuous hydrothermal flow synthesis.

    Science.gov (United States)

    Elouali, Sofia; Bloor, Leanne G; Binions, Russell; Parkin, Ivan P; Carmalt, Claire J; Darr, Jawwad A

    2012-01-24

    A rapid, clean, and continuous hydrothermal route to the synthesis of ca. 14 nm indium oxide (In(2)O(3)) nanoparticles using a superheated water flow at 400 °C and 24.1 MPa as a crystallizing medium and reagent is described. Powder X-ray diffraction (XRD) of the particles revealed that they were highly crystalline despite their very short time under hydrothermal flow conditions. Gas sensing substrates were prepared from an In(2)O(3) suspension via drop-coating, and their gas sensing properties were tested for response to butane, ethanol, CO, ammonia, and NO(2) gases. The sensors showed excellent selectivity toward ethanol, giving a response of 18-20 ppm.

  3. Preparation of MoB and MoB-MoSi{sub 2} composites by combustion synthesis in SHS mode

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, C.L. [Department of Mechanical and Automation Engineering, Da-Yeh University, 112 Shan-Jiau Road, Da-Tsuen, Changhua 51505, Taiwan (China)]. E-mail: clyeh@mail.dyu.edu.tw; Hsu, W.S. [Department of Mechanical and Automation Engineering, Da-Yeh University, 112 Shan-Jiau Road, Da-Tsuen, Changhua 51505, Taiwan (China)

    2007-08-16

    Combustion synthesis in the mode of self-propagating high-temperature synthesis (SHS) was carried out in the Mo-B and Mo-B-Si systems for the preparation of molybdenum boride MoB and the composite of MoB-MoSi{sub 2} from elemental powder compacts. Under a preheating temperature above 150 deg. C , the reaction of Mo with boron in the sample compact of Mo:B = 1:1 is characterized by a planar combustion front propagating in a self-sustaining and steady manner. As the preheating temperature or sample compaction density increased, combustion temperature was found to increase and the propagation rate of the combustion front was correspondingly enhanced. Moreover, the XRD analysis provides evidence of yielding nearly single-phase {alpha}-MoB from the Mo-B sample at equiatomic stoichiometry. In the synthesis of MoB-MoSi{sub 2} composites, the starting stoichiometry of the Mo-B-Si powder compact was varied so as to produce the final composites containing 20-80 mol% MoB. It was also found the increase of flame-front velocity and combustion temperature with increasing MoB content formed in the composite. The composition analysis by XRD shows excellent conversion from the Mo-B-Si powder compact to the MoB-MoSi{sub 2} composite through the SHS reaction; that is, in addition to a small amount of Mo{sub 5}Si{sub 3}, the as-synthesized composite is composed entirely of MoB and MoSi{sub 2}.

  4. Synthesis and modification of mesoporous silica and the preparation of molecular sieve thin films via pulsed laser deposition

    Science.gov (United States)

    Coutinho, Decio Heringer

    2001-07-01

    Hexagonal mesoporous DAM-1 (Dallas Amorphous Material-1) was prepared using Vitamin E TPGS as the structure-directing agent. Depending upon the temperature and gel composition, highly ordered and hydrothermally stable DAM-1 with various morphologies could be achieved including spheres, gyroids, discoid, hexagonal plates and rods. This synthesis was modified to prepare hybrid organic-inorganic amine and thiol bifunctionalized DAM-1 by direct co-condensation under acidic conditions. Patterned DAM-1 thin films were prepared on patterned transparencies utilizing pulsed laser deposition (PLD) and line patterning techniques. DAM-1 laser ablation onto the patterned substrate followed by hydrothermal treatment resulted in a densely packed film. Removal of the patterned lines by sonication revealed patterned DAM-1 films. Thin films of zeolite type X were also prepared using the PLD technique. Laser ablation of zeolite X onto TiN-coated silicon wafers followed by a hydrothermal treatment resulted in partially oriented, crystalline membranes. Hydrothermal treatment of PLD films on stainless steel mesh produced a coated wire mesh with a 3-mum thick zeolite X film. A novel strategy for imprinting mesoporous SBA-15 that combines a triblock copolymer template and a chiral ruthenium complex is reported. A chiral PEO helix was formed by the chiral ruthenium complex interaction with the block copolymer during the synthesis of SBA-15. Upon removal of the chiral ruthenium complex, a stereospecfic cavity was created. Preliminary results indicated stereoselective absorption of Delta or Λ-Ru(phen)3 2+ isomer from a racemic mixture could be achieved depending on the chirality of the PEO chain. Practicum Two. The industrial practicum report describes the process development unit (PDU) 3-pentenenitrile (3PN) refining operation. This distillation works was operated to refine crude 3PN product, which contained 3PN, 2-methyl-3-butenenitrile (2M3BN), and other byproducts. This report also

  5. Interfacing click chemistry with automated oligonucleotide synthesis for the preparation of fluorescent DNA probes containing internal xanthene and cyanine dyes.

    Science.gov (United States)

    Astakhova, I Kira; Wengel, Jesper

    2013-01-14

    Double-labeled oligonucleotide probes containing fluorophores interacting by energy-transfer mechanisms are essential for modern bioanalysis, molecular diagnostics, and in vivo imaging techniques. Although bright xanthene and cyanine dyes are gaining increased prominence within these fields, little attention has thus far been paid to probes containing these dyes internally attached, a fact which is mainly due to the quite challenging synthesis of such oligonucleotide probes. Herein, by using 2'-O-propargyl uridine phosphoramidite and a series of xanthenes and cyanine azide derivatives, we have for the first time performed solid-phase copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) click labeling during the automated phosphoramidite oligonucleotide synthesis followed by postsynthetic click reactions in solution. We demonstrate that our novel strategy is rapid and efficient for the preparation of novel oligonucleotide probes containing internally positioned xanthene and cyanine dye pairs and thus represents a significant step forward for the preparation of advanced fluorescent oligonucleotide probes. Furthermore, we demonstrate that the novel xanthene and cyanine labeled probes display unusual and very promising photophysical properties resulting from energy-transfer interactions between the fluorophores controlled by nucleic acid assembly. Potential benefits of using these novel fluorescent probes within, for example, molecular diagnostics and fluorescence microscopy include: Considerable Stokes shifts (40-110 nm), quenched fluorescence of single-stranded probes accompanied by up to 7.7-fold light-up effect of emission upon target DNA/RNA binding, remarkable sensitivity to single-nucleotide mismatches, generally high fluorescence brightness values (FB up to 26), and hence low limit of target detection values (LOD down to <5 nM). Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Preparing student teachers to integrate ICT in classroom practice: a synthesis of qualitative evidence

    NARCIS (Netherlands)

    Tondeur, J.; van Braak, J.; Guoyuan, S.; Voogt, Joke; Fisser, Petra; Ottenbreit-Leftwich, A.S.

    2012-01-01

    This study reviewed qualitative studies that focused on strategies to prepare pre-service teachers to integrate technology into their lessons. A meta-ethnography approach was utilized to locate, critically appraise, and synthesize the results of these studies. Based on an extensive search in the Web

  7. The effect of Centella asiatica, vitamins, glycolic acid and their mixtures preparations in stimulating collagen and fibronectin synthesis in cultured human skin fibroblast.

    Science.gov (United States)

    Hashim, Puziah

    2014-03-01

    Centella asiatica (Linn.) Urban is well known in promoting wound healing and provides significant benefits in skin care and therapeutic products formulation. Glycolic acid and vitamins also play a role in the enhancement of collagen and fibronectin synthesis. Here, we evaluate the specific effect of Centella asiatica (CA), vitamins, glycolic acid and their mixture preparations to stimulate collagen and fibronectin synthesis in cultured human fibroblast cells. The fibroblast cells are incubated with CA, glycolic acid, vitamins and their mixture preparations for 48 h. The cell lysates were analyzed for protein content and collagen synthesis by direct binding enzyme immunoassay. The fibronectin of the cultured supernatant was measured by sandwich enzyme immunoassay. The results showed that CA, glycolic acid, vitamins A, E and C significantly stimulate collagen and fibronectin synthesis in the fibroblast. Addition of glycolic acid and vitamins to CA further increased the levels of collagen and fibronectin synthesis to 8.55 and 23.75 μg/100 μg, respectively. CA, glycolic acid, vitamins A, E, and C, and their mixtures demonstrated stimulatory effect on both extra-cellular matrix synthesis of collagen and fibronectin in in vitro studies on human foreskin fibroblasts, which is beneficial to skin care and therapeutic products formulation.

  8. Radiohalogenation of biomolecules. An experimental study on radiohalogen preparation, precursor synthesis, radiolabeling and biodistribution

    Energy Technology Data Exchange (ETDEWEB)

    Koziorowski, J

    1998-10-01

    Radiohalogens are widely used in nuclear medicine, both as tool for diagnostic in vivo imaging, and in radionuclide therapy. This study deals with the use of radiohalogens; separation, precursor synthesis, labeling and biological behavior. The focus is on {sup 211}At and {sup 124}I, the former being a candidate for nuclide therapy and the latter potentially useful for diagnostic imaging and Auger-electron based radiotherapy. For astatine the separation, labeling and some biological behavior is described, and for iodine the latter two. Astatine was separated from an irradiated bismuth target by dry distillation. A novel cryotrap was developed for the isolation of astatine and subsequent synthesis of radiolabeled compounds. 5-[{sup 211}At]astato-2`-deoxyuridine (AUdR) and N-succinimidyl-4-[{sup 211}At]astatobenzoate (SAB) were synthesized in 95% respectively 90% radiochemical yields. The former is incorporated into DNA of proliferating cells and can therefore be used as an endoradiotherapeutic agent. The latter is a conjugate for the astatination of proteins. Human epidermal growth factor (hEGF) was tagged with astatine using three approaches: a) direct labeling of native hEGF, b) conjugation with SAB, and c) direct labeling of an hEGF - 7-(3-aminopropyl)-7,8-dicarba-nido-undecaborate(1-) conjugate. The overall labeling yields were 3.5% for direct labeling, 44% for SAB and 70% for the hEGF-nido-carborane conjugate. A new route to N-succinimidyl 3- and 4- [{sup 124}I]iodobenzoate, two reagents for radioiodination of proteins is described affording 90% radiochemical yield. Three radioiodinated analogs of PK11195, 1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)isoquinoline-3-carboxyam ide, a peripheral-type benzodiazepine receptor antagonist, were synthesized. All three analogs were obtained in >90% radiochemical yield. Synthesis and application of 5-[{sup 124}I]iodo-2`-deoxyuridine (IUdR) is presented. The closo-dodecaborate anion was evaluated as prosthetic group for

  9. SYNTHESIS OF POLYETHYLENE OXIDE (PEO–CHITOSAN HYDROGEL PREPARED BY GAMMA RADIATION TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Erizal Erizal

    2011-07-01

    Full Text Available Crosslinked PEO hydrogel containing chitosan for wound dressing has been prepared by gamma radiation technique. Chitosan solutions with different concentration (0.5-2% w/v have been blended with 5% aqueous solution of PEO and irradiated at the doses 20-40 kGy by gamma rays. The copolymers were characterized by Fourier transform infra red spectroscopy and their physico-chemical properties of hydrogels were evaluated in terms of gel fraction, swelling ratio, elongation at break and antimicrobial activities. It was found that under maximum condition of incorporation 1% chitosan with irradiation dose of 20 kGy, PEO-chitosan hydrogels with high gel fraction (85%, swelling ratio (10 g/g and elongation at break (145% were obtained. The examination of the microbe penetration shows that the prepared hydrogels can be considered as a good barrier against microbes. Thus, PEO-chitosan hydrogel showed satisfactory properties for use as a wound dressing.

  10. Synthesis and Characterization of SnO2 Nanostructures Prepared by a Facile Precipitation Method

    Directory of Open Access Journals (Sweden)

    L. Nejati-Moghadam

    2015-01-01

    Full Text Available In this paper, tin dioxide nanoparticles were synthesized by a fast and simple co-precipitation method. For SnO2 preparation, we used ammonia as precipitation agent and bis (acetylacetone ethylene diamineas as capping agent. By changing in SnCl4, acacen mole-ratio different morphologies were obtained. This semiconductor nanostructure has photo-catalyst activities and can degrade organic dyes as water pollution. The synthesized materials were characterized by X-ray diffraction (XRD pattern, scanning electron microscopy (SEM and Fourier transform infrared (FTIR spectroscopy. In situ poly vinyl alcohol-tin dioxide nanocomposite was prepared and results show that the SnO2 nanostructure can improve flame retardant property of the PVA matrix.

  11. Synthesis and Characterization of SnO2 Nanostructures Prepared by a Facile Precipitation Method

    OpenAIRE

    L. Nejati-Moghadam; A. Esmaeili Bafghi-Karimabad; M. Salavati-Niasari; H. Safardoust

    2015-01-01

    In this paper, tin dioxide nanoparticles were synthesized by a fast and simple co-precipitation method. For SnO2 preparation, we used ammonia as precipitation agent and bis (acetylacetone) ethylene diamineas as capping agent. By changing in SnCl4, acacen mole-ratio different morphologies were obtained. This semiconductor nanostructure has photo-catalyst activities and can degrade organic dyes as water pollution. The synthesized materials were characterized by X-ray diffraction (XRD) pattern, ...

  12. Structural, electrical and dielectric properties of spinel nickel ferrite prepared by soft mechanochemical synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Lazarević, Zorica Ž., E-mail: lzorica@yahoo.com [Institute of Physics, University of Belgrade, P.O. Box 68, Pregrevica 118, Zemun, Belgrade (Serbia); Jovalekić, Čedomir [The Institute for Multidisciplinary Research, University of Belgrade, Kneza Višeslava 1, Belgrade (Serbia); Sekulić, Dalibor L. [Faculty of Technical Sciences, University of Novi Sad, Trg Dositeja Obradovića 6, Novi Sad (Serbia); Milutinović, Aleksandra [Institute of Physics, University of Belgrade, P.O. Box 68, Pregrevica 118, Zemun, Belgrade (Serbia); Baloš, Sebastian; Slankamenac, Miloš [Faculty of Technical Sciences, University of Novi Sad, Trg Dositeja Obradovića 6, Novi Sad (Serbia); Romčević, Nebojša Ž. [Institute of Physics, University of Belgrade, P.O. Box 68, Pregrevica 118, Zemun, Belgrade (Serbia)

    2013-10-15

    Graphical abstract: - Highlights: • Sintered NiFe{sub 2}O{sub 4} was prepared by a soft mechanochemical route from mixture powders. • XRD and Raman measurements indicate that the prepared samples have spinel structure. • The activation energy ΔE are 0.653 and 0.452 eV for NiFe{sub 2}O{sub 4} samples. • Ferrite from Ni(OH){sub 2}/Fe{sub 2}O{sub 3} has lower DC conductivity than from Ni(OH){sub 2}/Fe(OH){sub 3} powders. • The values of dielectric constant of samples NiFe{sub 2}O{sub 4} are 70 and 200, respectively. - Abstract: Nickel ferrite, NiFe{sub 2}O{sub 4} was prepared by a soft mechanochemical route from a mixture of (1) Ni(OH){sub 2} and α-Fe{sub 2}O{sub 3} and (2) Ni(OH){sub 2} and Fe(OH){sub 3} powders in a planetary ball mill for 25 h. The powder samples were sintered at 1100 °C for 2 h and were characterized by X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM). Impedance spectroscopy techniques were used to study the effect of grain and grain boundary on the electrical properties of the prepared samples. A difference in dielectric constant (ε) and dielectric loss tangent (tan δ) of NiFe{sub 2}O{sub 4} samples obtained by the same methods but starting from different initial components was observed.

  13. A Facile Synthesis of Fully Protected meso-Diaminopimelic Acid (DAP and Its Application to the Preparation of Lipophilic N-Acyl iE-DAP

    Directory of Open Access Journals (Sweden)

    Hiroki Takahata

    2013-01-01

    Full Text Available Synthesis of beneficial protected meso-DAP 9 by cross metathesis of the Garner aldehyde-derived vinyl glycine 1b with protected allyl glycine 2 in the presence of Grubbs second-generation catalyst was performed. Preparation of lipophilic N-acyl iE-DAP as potent agonists of NOD 1-mediated immune response from 9 is described.

  14. Photoelectroactivity of bismuth vanadate prepared by combustion synthesis: effect of different fuels and surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Afonso, Renata; Serafim, Jessica A.; Lucilha, Adriana C.; Dall' Antonia, Luiz H., E-mail: luizh@uel.br [Universidade Estadual de Londrina (UEL), PR (Brazil). Dept. Quimica. Lab. de Eletroquimica e Materiais; Silva, Marcelo R. [Universidade Estadual Paulista Julio de Mesquita Filho (CTI/UNESP), Bauru, SP (Brazil). Colegio Tecnico Industrial; Lepre, Luiz F.; Ando, Romulo A. [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Quimica. Lab. de Espectroscopia Molecular

    2014-04-15

    The bismuth vanadate (BiVO{sub 4}) is a semiconductor that has attracted much attention due to the photocatalytic efficiency in the visible light region. The objective of this work was to synthesize monoclinic BiVO{sub 4} by solution combustion synthesis, with different surfactants and fuels and apply it as photoelectrodes. The characterization by infrared spectroscopy and Raman spectroscopy showed that all samples showed characteristic bands of the monoclinic structure BiVO{sub 4}. The samples synthesized with glycine and glycine/Tween® 80 had V{sub 2}O{sub 5}. The film obtained from the alanine/ Tween® 80 showed highest photocurrent values, which may be related to smaller size particles (200 to 300 nm) observed by scanning electron microscopy images. The films obtained using alanine showed highest values of rate constant reaction and percentage discoloration of methylene blue. (author)

  15. Continuous Preparation of Water-Dispersible Magnetite Nanoparticles by Electrochemical Synthesis.

    Science.gov (United States)

    Kim, Do-Hyeong; Park, Jin-Soo; Kang, Moon-Sung

    2018-08-01

    Highly water-dispersible magnetic nanoparticles were synthesized by convenient electrochemical techniques using a continuous flow reactor. The surface properties of the magnetic nanoparticles (MNPs) were modified with hydrophilic organic ligands during the electrochemical synthesis process to control the degree of dispersion in water. The kind of hydrophilic low-molecular weight polymers or surfactants influenced the sizes of the particles ranged between 25-40 nm (in diameter) and their size distribution. Chitosan-modified MNPs exhibited the most uniform particle size distribution among the MNPs synthesized in this study as well as excellent dispersion stability and magnetic properties in water after the crosslinking of the amino groups in chitosan. Especially, the dispersion stability of the MNPs in water was systematically investigated via a light scattering analysis.

  16. Bioactivity studies of calcium magnesium silicate prepared from eggshell waste by sol–gel combustion synthesis

    Directory of Open Access Journals (Sweden)

    Rajan Choudhary

    2015-06-01

    Full Text Available The present study focused on the synthesis of calcium magnesium silicate (akermanite, Ca2MgSi2O7 using eggshell biowaste (as calcium source, magnesium nitrate and tetraethyl orthosilicate (TEOS as starting materials. Sol–gel combustion method was adopted to obtain calcium magnesium silicate. Citric acid was used as a fuel (reducing agent and nitrate ions present in the metal nitrates acts as an oxidizing agent during combustion process. The characterization of synthesized calcium magnesium silicate was carried out by powder X-ray diffraction (XRD, Fourier transform infrared (FTIR and scanning electron microscopy (SEM techniques. Calcium magnesium silicate crystallite size was observed in nano regime which can effectively mimic natural bone apatite composition. In-vitro bioactivity was investigated by immersing calcium magnesium silicate pellet in simulated body fluid (SBF for three weeks. Results show effective deposition of crystallized hydroxyapatite (HAP layer on its surface and predicting its possibilities for applications in hard tissue regeneration.

  17. Carbon Nanotube Synthesis in a Flame with Independently Prepared Laser-Ablated Catalyst Particles

    Science.gov (United States)

    VanderWal, Randall L.; Berger, Gordon M.; Ticich, Thomas M.

    2003-01-01

    Laser ablation has been used ex situ to create metal nanoparticles for introduction into a reactive pyrolysis flame. By prior synthesis of the metal nanoparticles, the effects of the reactive gases can be clearly separated from the pyrolysis chemistry of a solvent carrier, as when nebulized solutions are used. Moreover, varying reactivity issues associated with particle growth and size are bypassed. Our results show that Fe selectively reacts with CO to produce nanotubes, whereas Ni selectively reacts with C2H2 to produce nanofibers. These observations are interpreted through the donation and withdrawal of electron density between the adsorbate's molecular orbitals and surface atoms of the metal nanoparticle. The rate of reaction of Ni with only C2H2 is found to be greater than the rate with C2H2 and CO. This suggests that CO inhibits the Ni-catalyzed reaction.

  18. SYNTHESIS AND CHARACTERIZATION OF CROSSLINKED POLYACRYLAMIDE (PAAM-CARRAGEENAN HYDROGELS SUPERBASORBENT PREPARED BY GAMMA RADIATION

    Directory of Open Access Journals (Sweden)

    Erizal Erizal

    2010-06-01

    Full Text Available A series of superabsorbent hydrogels were prepared from acrylamide and carrageenan by gamma irradiation at room temperature. Carrageenan solutions with different concentration (0.5%, 1%, 1.5%, 2% have been blended with 5% of acrylamide and irradiated at doses 20-40 kGy. The properties of the prepared hydrogel were evaluated in terms of the gel fraction and the kinetics swelling was studied. It was found that the incorporation only 2% carrageenan (kappa with 5% acrylamide can produces an elastic hydrogel when irradiated with gamma rays up to 40 kGy. Under optimum conditions, poly(acrylamide-carrageenan hydrogels with gel fraction ~ 60% and optimum swelling 250 g/g were prepared gamma radiolyticcally from aqueous solution containing 5% acrylamide and 2% carrageenan at the doses 20-40 kGy. The FT-IR spectra indicated that network of irradiated PAAM-carrageenan hydrogel was in the semi IPN structure. The hydrogels were also found to be sensitive to ionic strength of the medium, pH and temperature.   Keywords: carrageenan, acrylamide, irradiation, superbasorbent, crosslinking

  19. Process for preparing cracked gases by catalytic cracking of hydrocarbons with a C-number of C/sub 2/ to C/sub 30/

    Energy Technology Data Exchange (ETDEWEB)

    Nonnenmacher, H.; Rall, W.; Triebskorn, B.; Hupfer, L.

    1975-05-22

    A method is described to obtain gases by catalytic cracking of hydrocarbons having a C-number of C/sub 2/ to C/sub 30/ using steam at normal or raised pressure in the presence of nickel catalysts on a carrier material which consists of a prelayer and main layer where the conversion in the prelayer is carried out at 350 to 650/sup 0/C in the presence of a 35 to 55 weight percent nickel-containing catalyst, and in the main layer at 550 to 950/sup 0/C in the presence of a 15 to 25 weight percent nickel-containing catalyst. This is characterized in that a catalyst containing at least 0.5 weight percent of an alkali metal compound, calculated as oxide, is used in the prelayer, and a practically alkali-free catalyst or one containing less than 0.5 weight percent of an alkali metal compound, calculated as oxide, is used in the main layer.

  20. SYNTHESIS OF SnO₂/Cr PIGMENTS DOPED BY PRASEODYMIUM PREPARED BY DIFFERENT METHODS AND THEIR PIGMENTARY PROPERTIES

    Directory of Open Access Journals (Sweden)

    Jakub Trojan

    2016-07-01

    Full Text Available The violet SnO₂/Cr pigments in which a part of tin ions was substituted by praseodymium ions were examined. The compounds Sn0.99Cr0.005Pr0.005O₂ may represent a potential extension of the range of violet shades, especially in their use in ceramics. Pigments have been prepared by classical ceramic route i.e. solid state reaction method, also by the method of mechanoactivation and finally by a two-step process based on the suspension mixing of the initial reagents. The temperature range for the reaction was from 1350 to 1500 °C. Pigments were characterised in terms of colour, they were also studied with respect to their phase composition as well as the particles size distribution. X-ray analysis confirmed that the synthesis temperature 1350 °C is sufficient to get mono-phase compounds in case of all ways of preparation. Mechanoactivation and two-step process can be suggested as the preferable method for acquirement of pigments with the most interesting colour.

  1. New synthesis route of active substance d,l-HMPAO for preparation Technetium Tc99m Exametazime.

    Science.gov (United States)

    Pijarowska-Kruszyna, Justyna; Karczmarczyk, Urszula; Jaroń, Antoni Włodzimierz; Laszuk, Ewa; Radzik, Marcin; Garnuszek, Piotr; Mikołajczak, Renata

    2017-01-01

    Technetium Tc99m Exametazime (99mTc-HMPAO) is currently used as a radiopharmaceutical for determining regional cerebral blood flow and for the labelling of autologous leucocytes for infection and inflammation imaging. The HMPAO ligand exists in two diastereomeric forms: d,l and meso. Usually, the substance is obtained in low chemical yield in a time consuming procedure. Furthermore, the final product still contains some amounts of the meso-form. The aim of this study was to develop the efficient, reliable and fast method for isolation of the d,l-HMPAO, which would provide the ligand with high purity and free from the meso-diastereomer. The mixture of the meso- and d,l-HMPAO was synthesized in two-steps by condensation of propanediamine with keto-oxime and the reduction of the obtained bisimine. The d- and l-enantiomers were separated individually directly from this mixture by repeated crystallizations from ethanol as their tartrate salts and pooled together in equal proportions. That substance was characterized for its identity and isomeric purity using IR, HPLC and GC methods. The meso-free d,l-HMPAO was used for the preparation of the radiopharmaceutical freeze-dried kit for technetium-99m radiolabelling. Quality assessment of obtained 99mTc-d,l-HMPAO complex was performed according to the current Ph.Eur. monograph 1925 and USP monograph - Technetium Tc99m Exametazime Injection. To verify its biological activity, the kit-prepared 99mTc-d,l-HMPAO has been used for the white blood cell (WBC) labelling. According to the proposed synthesis route the d,l-HMPAO was obtained with around 18-20% yield in the total time of 10 days. The ligand identity was confirmed and the HPLC analysis revealed more than 99% chemical purity. The undesired meso-form was not detected. Freeze dried kit formulation for 99mTc-labelling of d,l-HMPAO has been established and four batches of kits were manufactured. The radiochemical purity of 99mTc-d,l-HMPAO complex was high (> 95% of lipophilic

  2. Hydrophobically assisted switching phase synthesis: the flexible combination of solid-phase and solution-phase reactions employed for oligosaccharide preparation.

    Science.gov (United States)

    Bauer, Jörg; Rademann, Jörg

    2005-05-25

    Hydrophobically assisted switching phase (HASP) synthesis is a concept that allows the choice between the advantages of solid-supported chemistry and those of solution-phase synthesis. Starting from the examination of adsorption and desorption properties of hydrophobic molecules to and from reversed-phase silica, we designed a dilipid as a quantitative and fully reversible HASP anchor, permitting final product release. The utility of this new tool in synthetic organic chemistry was demonstrated on oligosaccharide preparation. The synthesis of a pentarhamnoside was accomplished by repetitive glycosylation reactions. Glycosylations were conducted preferably in solution, whereas all protecting group manipulations were performed on solid support. Without the need for chromatographic purification of intermediates, the HASP system furnished the final product after 12 linear steps with average yields of 94% per step at a scale of 0.1 mmol, thus overcoming several of the limitations encountered in the solid-phase synthesis of complex carbohydrates.

  3. Low temperature synthesis of nanocrystalline magnesium aluminate with high surface area by surfactant assisted precipitation method: Effect of preparation conditions

    Energy Technology Data Exchange (ETDEWEB)

    Mosayebi, Zeinab [Institute of Nanoscience and Nanotechnology, University of Kashan, Kashan (Iran, Islamic Republic of); Rezaei, Mehran, E-mail: rezaei@kashanu.ac.ir [Institute of Nanoscience and Nanotechnology, University of Kashan, Kashan (Iran, Islamic Republic of); Catalyst and Advanced Materials Research Laboratory, Chemical Engineering Department, Faculty of Engineering, University of Kashan, Kashan (Iran, Islamic Republic of); Hadian, Narges [Institute of Nanoscience and Nanotechnology, University of Kashan, Kashan (Iran, Islamic Republic of); Kordshuli, Fazlollah Zareie [Shiraz Petrochemical Co., Shiraz (Iran, Islamic Republic of); Meshkani, Fereshteh [Catalyst and Advanced Materials Research Laboratory, Chemical Engineering Department, Faculty of Engineering, University of Kashan, Kashan (Iran, Islamic Republic of)

    2012-09-15

    Highlights: ► MgAl{sub 2}O{sub 4} showed a high surface area and nanocrystalline structure. ► Addition of polymeric surfactant affected the structural properties of MgAl{sub 2}O{sub 4}. ► MgAl{sub 2}O{sub 4} prepared with surfactant showed a hollow cylindrical shape. -- Abstract: A surfactant assisted co-precipitation method was employed for the low temperature synthesis of magnesium aluminate spinel with nanocrystalline size and high specific surface area. Pluronic P123 triblock copolymer and ammonia solution were used as surfactant and precipitation agent, respectively. The prepared samples were characterized by thermal gravimetric and differential thermal gravimetric analyses (TG/DTG), X-ray diffraction (XRD), N{sub 2} adsorption (BET) and transmission electron microscopy (TEM) techniques. The effects of several process parameters such as refluxing temperature, refluxing time, pH, P123 to metals mole ratio (P123/metals) and calcination temperature on the structural properties of the samples were investigated. The obtained results showed that, among the process parameters pH and refluxing temperature have a significant effect on the structural properties of samples. The results revealed that increase in pH from 9.5 to 11 and refluxing temperature from 40 °C to 80 °C increased the specific surface area of prepared samples in the range of 157–188 m{sup 2} g{sup −1} and 162–184 m{sup 2} g{sup −1}, respectively. The XRD analysis showed the single-phase MgAl{sub 2}O{sub 4} was formed at 700 °C.

  4. Synthesis and Study of Guest-Rebinding of MIP Based on MAA Prepared using Theophylline Template

    Science.gov (United States)

    Nurhayati, T.; Yanti; Royani, I.; Widayani; Khairurrijal

    2016-08-01

    A molecularly imprinted polymer (MIP) based on methacrylic acid (MAA) monomer and theophylline template has been synthesized using a modified bulk polymerization method. Theophylline was employed as a template and it formed a complex with MAA through hydrogen bonding. Self-assembly of template-monomer was followed by cross-linking process using ethylene glycol dimethacrylate (EGDMA) cross-linker. The polymerization process was initiated by thermal decomposition of benzoyl peroxide (BPO) as the initiator at 60oC after cooling treatment at -5oC. After 7 hours, a rigid polymer was obtained and followed by grinding the polymer and removing the template. As a reference, a nonimprinted polymer (NIP) has also been synthesized using similar procedure by excluding the template. FTIR study was carried out to investigate the presence of theophylline in the as- prepared polymer, MIP, and NIP. The spectra indicated that theophylline was successfully incorporated in the as-prepared polymer. This result was also confirmed by EDS analysis showing that N atoms of the as-prepared polymer were derived from amino group of theophylline. Furthermore, the polymer particles of MIP were irregular in shape and size as shown by its SEM image. The capability of guest-rebinding of the MIP was analyzed through Batchwise guest-binding experiment. The results showed that for initial concentration of theophylline in methanol/chloroform (1/1, v/v) of 0.333 mM, the binding capacity of the MIP was 23.22 /mol/g. Compared to the MIP, the adsorption capacity of the NIP was only 3.73 /mol/g. This result shows that MIP has higher affinity than NIP.

  5. Synthesis and Characterization of Multi-Component Polymeric Materials Prepared via Free Radical Polymerization

    OpenAIRE

    Pasquale, Anthony J.

    2002-01-01

    High molecular weight star-shaped polystyrenes were prepared via the coupling of 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) terminated polystyrene oligomers with divinylbenzene (DVB) in m-xylene at 138 °C. Linear polystyrene oligomers (Mn = 19,300 g/mol, Mw/Mn = 1.10) were synthesized in bulk styrene using benzoyl peroxide in the presence of TEMPO at approximately 130 °C. In situ mid-infrared spectroscopy was successfully utilized to follow initiation, monomer conversion, and polymer fo...

  6. Preparation of polydopamine coated Fe₃O₄ nanoparticles and their application for enrichment of polycyclic aromatic hydrocarbons from environmental water samples.

    Science.gov (United States)

    Wang, Yixuan; Wang, Saihua; Niu, Hongyun; Ma, Yurong; Zeng, Tao; Cai, Yaqi; Meng, Zhaofu

    2013-03-29

    Core/shell structured magnetic Fe3O4/polydopamine (Fe3O4/PDA) nanoparticles have been successfully synthesized and developed as a magnetic solid-phase extraction (SPE) adsorbent in dispersion mode for the determination of trace polycyclic aromatic hydrocarbons (PAHs) in environmental samples. The Fe3O4/PDA synthetic procedure is simple and involves no organic solvents. Only 20mg of Fe3O4/PDA adsorbents are required to extract PAHs from 500mL water samples. The adsorption attains equilibrium rapidly and analysts are eluted with acetonitrile readily. The extraction efficiency is not influenced by salt concentrations up to 300mM and pH values over the range 4-11. Under optimized conditions, the detection limits of PAHs are in the range of 0.5-1.9ngL(-1). The accuracy of the method is evaluated by the recoveries of PAHs from environmental samples. Good recoveries (76.4-107%) with low relative standard deviations from 1.0% to 9.7% are achieved. Comparison study shows that the recoveries of target PAHs are low when they are extracted using traditional SPE method even with the addition of methanol or tetrabutylammonium bromide surfactants in water samples, suggesting great application potential of magnetic SPE method to preconcentrate highly hydrophobic contaminants (such as PAHs) from large volume of water samples. This new SPE method provides several advantages, such as simplicity, low environmental impact, high extraction efficiency, high breakthrough volumes, convenient extraction procedure, and short analysis time. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Effect of preparation conditions on the catalytic performance of cobalt manganese oxide catalysts for conversion of synthesis gas to light olefins

    Energy Technology Data Exchange (ETDEWEB)

    Mirzaei, Ali A.; Faizi, Mostafa; Habibpour, Razieh [Department of Chemistry, Faculty of Sciences, University of Sistan and Baluchestan, Zahedan 98135-674 (Iran, Islamic Republic of)

    2006-06-07

    Cobalt manganese oxides are prepared using a co-precipitation procedure and studied for the conversion of synthesis gas to light olefins. In particular, the effect of a range of preparation variables is investigated in detail. The variables investigated include the precipitate ageing time, pH and temperature of precipitation, the [Co]/[Mn] ratio of the precipitation solution and also reactor conditions such as reaction temperature and H{sub 2}/CO molar feed ratio. The effect of different supports on the activity and selectivity of catalysts are also studied. The optimum preparation conditions are identified with respect to catalytic performance for the conversion of synthesis gas to ethylene and propylene. The results are interpreted in terms of the structure of the active catalyst. Generally it has been concluded that catalysts containing cobalt manganese mixed phases are found to be the most active. (author)

  8. Synthesis and characterization of nanocomposites based on PANI and carbon nanostructures prepared by electropolymerization

    Energy Technology Data Exchange (ETDEWEB)

    Petrovski, Aleksandar; Paunović, Perica [Faculty of Technology and Metallurgy, SS Cyril and Methodius University, Rudjer Bošković, 16, 1000, Skopje (Macedonia, The Former Yugoslav Republic of); Avolio, Roberto; Errico, Maria E.; Cocca, Mariacristina; Gentile, Gennaro [Institute for Polymers, Composites and Biomaterials, National Research Council, Via Campi Flegrei 34, 80078, Pozzuoli, Napoli (Italy); Grozdanov, Anita, E-mail: anita.grozdanov@yahoo.com [Faculty of Technology and Metallurgy, SS Cyril and Methodius University, Rudjer Bošković, 16, 1000, Skopje (Macedonia, The Former Yugoslav Republic of); Avella, Maurizio [Institute for Polymers, Composites and Biomaterials, National Research Council, Via Campi Flegrei 34, 80078, Pozzuoli, Napoli (Italy); Barton, John [Tyndall National Institute, University College Cork, Dyke Parade, T12 R5CP, Cork (Ireland); Dimitrov, Aleksandar [Faculty of Technology and Metallurgy, SS Cyril and Methodius University, Rudjer Bošković, 16, 1000, Skopje (Macedonia, The Former Yugoslav Republic of)

    2017-01-01

    Nanocomposites based on polyaniline (PANI) and carbon nanostructures (CNSs) (graphene (G) and multiwall carbon nanotubes (MWCNTs)) were prepared by in situ electrochemical polymerization. CNSs were inserted into the PANI matrix by dispersing them into the electrolyte before the electropolymerization. Electrochemical characterization by means of cyclic voltammetry and steady state polarization were performed in order to determine conditions for electro-polymerization. Electro-polymerization of the PANI based nanocomposites was carried out at 0.75 V vs. saturated calomel electrode (SCE) for 40 and 60 min. The morphology and structural characteristics of the obtained nanocomposites were studied by scanning electron microscopy (SEM) and Raman spectroscopy, while thermal stability was determined using thermal gravimetric analysis (TGA). According to the morphological and structural study, fibrous and porous structure of PANI based nanocomposites was detected well embedding both G and MWCNTs. Also, strong interaction between quinoidal structure of PANI with carbon nanostructures via π–π stacking was detected by Raman spectroscopy. TGA showed the increased thermal stability of composites reinforced with CNSs, especially those reinforced with graphene. - Highlights: • Nanocomposites of PANI with carbon nanostructures were prepared for sensing application. • By cyclic voltammetry, conductive form of PANI (green colored emeraldine phase) is obtained 0.75 V • Using 4 Probe method, nanocomposite PANI/CNS tablet was tested for sensing application. • Micro-structural properties of nanocomposites were studied by SEM, TGA and Raman analysis.

  9. Magnetic properties of hematite (α-Fe2O3) nanoparticles prepared by hydrothermal synthesis method

    Science.gov (United States)

    Tadic, Marin; Panjan, Matjaz; Damnjanovic, Vesna; Milosevic, Irena

    2014-11-01

    Hematite (α-Fe2O3) nanoparticles are successfully synthesized by using the hydrothermal synthesis method. An X-ray powder diffraction (XRPD) of the sample shows formation of the nanocrystalline α-Fe2O3 phase. A transmission electron microscopy (TEM) measurements show spherical morphology of the hematite nanoparticles and narrow size distribution. An average hematite nanoparticle size is estimated to be about 8 nm by TEM and XRD. Magnetic properties were measured using a superconducting quantum interference device (SQUID) magnetometry. Investigation of the magnetic properties of hematite nanoparticles showed a divergence between field-cooled (FC) and zero-field-cooled (ZFC) magnetization curves below Tirr = 103 K (irreversibility temperature). The ZFC magnetization curve showed maximum at TB = 52 K (blocking temperature). The sample did not exhibit the Morin transition. The M(H) (magnetization versus magnetic field) dependence at 300 K showed properties of superparamagnetic iron oxide nanoparticles (SPION). The M(H) data were successfully fitted by the Langevin function and magnetic moment μp = 657 μB and diameter d = 8.1 nm were determined. Furthermore, magnetic measurements showed high magnetization at room temperature (MS = 3.98 emu/g), which is desirable for application in spintronics and biomedicine. Core-shell structure of the nanoparticles was used to describe high magnetization of the hematite nanoparticles.

  10. Preparation of PBO/ZnO fibers by hydrothermal synthesis method and its properties

    Science.gov (United States)

    Ma, Qi; Wang, Bin; Lv, Junwei; Li, Yuntao; Li, Hui; Zhao, Chunxia

    2017-08-01

    In this article, zinc oxide (ZnO) nanoparticles were synthesized and deposited on the surface of PBO fibers through hydrothermal synthesis method. The structures and properties of PBO/ZnO fibers and PBO fibers were characterized by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), x-ray diffraction (XRD), Fourier transform infrared spectrum (FTIR), Thermogravimetric analysis (TG), and tensile testing. The results revealed that the PBO/ZnO fibers have good mechanical properties and high thermal stability. Moreover, the fibers exhibited excellent UV-blocking properties by putting them under UV irradiation of 313 nm. Specifically, ZnO coated fibers will lose only 18.93% of tensile strength after 50 h irradiation, and then will keep over 65% of tensile strength after 100 h UV irradiation. Additionally the interface shear strength is increased significantly, and the results also showed modified PBO fibers exhibited excellent hydrophobic quality. So the functional materials have great potentials in future engineering applications.

  11. Enzymatic glycoprotein synthesis: Preparation of ribonuclease glycoforms via enzymatic glycopeptide condensation and glycosylation

    Energy Technology Data Exchange (ETDEWEB)

    Witte, K.; Sears, P.; Martin, R.; Wong, C.H. [Scripps Research Inst., La Jolla, CA (United States)

    1997-03-05

    In order to study the effects carbohydrates have on glycoprotein structure and funciton, it is imperative to be able to synthesize the appropriate natural and non-natural glycoprotein variants in a single form. Because the available in vivo techniques provide only heterogeneous mixtures of different glycoforms, enzymatic in vitro methodologies have been pursued. Using the N-glycoprotein RNase B as a model system, the oligosaccharide was removed leaving only the N-acetylglucosamine as a `tag` to the site of glycosylation. Glycosyltransferases were then used to build a unique carbohydrate moiety. A new RNase glycoform containing the branched oligosccharide, sialyl Lewis X or the Hg derivative, was synthesized enzymatically to demonstrate the feasibility of the method. In addition, the monoglycosylated protein was digested into several smaller pieces by subtilisin BPN`. These fragments were religated by subtilisin 8397 to the full length RNase by addition glycerol; this method points to a new chemical-enzymatic process for the synthesis of glycoproteins using synthetic peptides and glycopeptides as substrates for enzymatic ligation followed by further enzymatic glycosylations. 29 refs., 6 figs.

  12. UO2 Particle Standards: Synthesis, Purification & Planchet Preparation

    Energy Technology Data Exchange (ETDEWEB)

    Barrett, Christopher A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Anheier, Norman C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-03-31

    The IAEA has previously indicated its desire for reliable provision of suitable reference materials in support of environmental sample analysis and sustained advancement at the Department of Safeguards, as laid out in the Long Term R&D plan (LTRD 10.1 & 10.2). In a recent meeting between NPAC, the IAEA and PNNL, this pressing need was directly outlined by the IAEA as having two main objectives. The first pertains to current operations, such as instrument calibrations and evaluation of bias across the Network of Analytical Laboratories and requires particles on the order of 300-500 nm in diameter. The second need for particle reference material would directly support the IAEA’s ongoing R&D efforts and calls for smaller particles ranging from 50 -100 nm in size. As such, the IAEA has expressed a great deal of interest in the newly established synthesis capabilities at PNNL, initially cultivated through a PNNL LDRD project to address the particle-standards shortcomings for uranium oxide material. The joint meeting concluded with a request by the IAEA for 1-2 planchet samples containing PNNL’s UO2 particulate material, to be delivered in the near-term. This report outlines the steps taken to meet that request and includes some basic characteristics of the samples sent to the IAEA.

  13. Green synthesis of silver nanoparticles in aloe vera plant extract prepared by a hydrothermal method and their synergistic antibacterial activity

    Directory of Open Access Journals (Sweden)

    Patcharaporn Tippayawat

    2016-10-01

    Full Text Available Background There is worldwide interest in silver nanoparticles (AgNPs synthesized by various chemical reactions for use in applications exploiting their antibacterial activity, even though these processes exhibit a broad range of toxicity in vertebrates and invertebrates alike. To avoid the chemical toxicity, biosynthesis (green synthesis of metal nanoparticles is proposed as a cost-effective and environmental friendly alternative. Aloe vera leaf extract is a medicinal agent with multiple properties including an antibacterial effect. Moreover the constituents of aloe vera leaves include lignin, hemicellulose, and pectins which can be used in the reduction of silver ions to produce as AgNPs@aloe vera (AgNPs@AV with antibacterial activity. Methods AgNPs were prepared by an eco-friendly hydrothermal method using an aloe vera plant extract solution as both a reducing and stabilizing agent. AgNPs@AV were characterized using XRD and SEM. Additionally, an agar well diffusion method was used to screen for antimicrobial activity. MIC and MBC were used to correlate the concentration of AgNPs@AV its bactericidal effect. SEM was used to investigate bacterial inactivation. Then the toxicity with human cells was investigated using an MTT assay. Results The synthesized AgNPs were crystalline with sizes of 70.70 ± 22-192.02 ± 53 nm as revealed using XRD and SEM. The sizes of AgNPs can be varied through alteration of times and temperatures used in their synthesis. These AgNPs were investigated for potential use as an antibacterial agent to inhibit pathogenic bacteria. Their antibacterial activity was tested on S. epidermidis and P. aeruginosa. The results showed that AgNPs had a high antibacterial which depended on their synthesis conditions, particularly when processed at 100 oC for 6 h and 200 oC for 12 h. The cytotoxicity of AgNPs was determined using human PBMCs revealing no obvious cytotoxicity. These results indicated that AgNPs@AV can be effectively

  14. Green synthesis of silver nanoparticles in aloe vera plant extract prepared by a hydrothermal method and their synergistic antibacterial activity.

    Science.gov (United States)

    Tippayawat, Patcharaporn; Phromviyo, Nutthakritta; Boueroy, Parichart; Chompoosor, Apiwat

    2016-01-01

    There is worldwide interest in silver nanoparticles (AgNPs) synthesized by various chemical reactions for use in applications exploiting their antibacterial activity, even though these processes exhibit a broad range of toxicity in vertebrates and invertebrates alike. To avoid the chemical toxicity, biosynthesis (green synthesis) of metal nanoparticles is proposed as a cost-effective and environmental friendly alternative. Aloe vera leaf extract is a medicinal agent with multiple properties including an antibacterial effect. Moreover the constituents of aloe vera leaves include lignin, hemicellulose, and pectins which can be used in the reduction of silver ions to produce as AgNPs@aloe vera (AgNPs@AV) with antibacterial activity. AgNPs were prepared by an eco-friendly hydrothermal method using an aloe vera plant extract solution as both a reducing and stabilizing agent. AgNPs@AV were characterized using XRD and SEM. Additionally, an agar well diffusion method was used to screen for antimicrobial activity. MIC and MBC were used to correlate the concentration of AgNPs@AV its bactericidal effect. SEM was used to investigate bacterial inactivation. Then the toxicity with human cells was investigated using an MTT assay. The synthesized AgNPs were crystalline with sizes of 70.70 ± 22-192.02 ± 53 nm as revealed using XRD and SEM. The sizes of AgNPs can be varied through alteration of times and temperatures used in their synthesis. These AgNPs were investigated for potential use as an antibacterial agent to inhibit pathogenic bacteria. Their antibacterial activity was tested on S. epidermidis and P. aeruginosa. The results showed that AgNPs had a high antibacterial which depended on their synthesis conditions, particularly when processed at 100 oC for 6 h and 200 oC for 12 h. The cytotoxicity of AgNPs was determined using human PBMCs revealing no obvious cytotoxicity. These results indicated that AgNPs@AV can be effectively utilized in pharmaceutical, biotechnological

  15. Synthesis, structural characterization and scalable preparation of new amino-zinc borates

    Energy Technology Data Exchange (ETDEWEB)

    Imer, M. R. [Departamento Estrella Campos; Facultad de Química; Universidad de la República; Montevideo; Uruguay; González, M. [Departamento Estrella Campos; Facultad de Química; Universidad de la República; Montevideo; Uruguay; Veiga, N. [Departamento Estrella Campos; Facultad de Química; Universidad de la República; Montevideo; Uruguay; Kremer, C. [Departamento Estrella Campos; Facultad de Química; Universidad de la República; Montevideo; Uruguay; Suescun, L. [Laboratorio de Cristalografía; Química del Estado Sólido y Materiales; Cátedra de Física; DETEMA; Facultad de Química; Arizaga, L. [Departamento Estrella Campos; Facultad de Química; Universidad de la República; Montevideo; Uruguay

    2017-01-01

    Zinc borates are important materials. We report the preparation of three novel ones: [Zn(NH3)3B4O5(OH)4]·H2O (ZB1), Zn3(H2B3O7)2·2NH3·4H2O (ZB2), and [Zn(NH3)4][B4O5(OH)4]·4H2O (ZB3).

  16. Fatty acid ethyl ester synthesis in the preparation of scotch whiskey.

    Science.gov (United States)

    Goss, K A; Alharethi, R; Laposata, M

    1999-04-01

    Fatty acid ethyl esters (FAEE), nonoxidative ethanol metabolites present in human organs commonly damaged by ethanol abuse, have been implicated as mediators of organ damage. FAEE are additives in various foods and beverages to provide flavor or fragrance, and therefore are common dietary lipid constituents. We hypothesized that FAEE could be generated during alcoholic beverage production because fatty acids are present within microorganisms and ethanol is generated during the fermentation process. In this report, we demonstrate that FAEE are present in commercially available scotch beverages, and that in the preparation of scotch, FAEE can be produced during the fermentation reaction as a result of FAEE synthase activity in the yeast. Following ingestion of scotch, preformed FAEE are delivered to GI tract. The consequences of ingestion of FAEE in scotch, if any, remain to be determined.

  17. Enzymatic synthesis and modification of structured phospholipids: recent advances in enzyme preparation and biocatalytic processes.

    Science.gov (United States)

    Hama, Shinji; Ogino, Chiaki; Kondo, Akihiko

    2015-10-01

    Phospholipids (PLs) containing specific polar head groups and fatty acids, artificially synthesized from a complex mixture of natural PLs, have considerable industrial applications. The biocatalytic approaches to synthesizing structured PLs are of great interest because the enzymes used show high selectivity and performance under mild conditions, leading to the generation of products that cannot easily be obtained by chemical catalysis. Although the limited supply of phospholipases (e.g., phospholipase D) has thus far been an obstacle to the widespread use of enzymatic processing, recent advances in enzyme preparation have opened up various applications for PL modification. In this review, attempts to increase the productivity and utility of microbial phospholipases and lipases are presented. We also summarize recent developments in enzyme-catalyzed modification of PLs, focusing particularly on the relevant reactions, bioreactor design, and novel proof-of-concept experiments.

  18. Preparative studies on the isolation of an enzyme associated with carthamin synthesis in Carthamus tinetorius L.

    Directory of Open Access Journals (Sweden)

    Takao Homma

    2014-01-01

    Full Text Available Preliminary operations for the isolation of an enzyme associated with cathamin synthesis (carthamin-synthesizing enzyme were done with a soluble extract of safflower seedlings. Ethanol and acetone seriously affected the solubility and the activity of the enzyme. Ammonium sulfate fractionation, calcium acetate precipitation and protamine sulfate treatment were all useful techniques for removing inert protein from the crude extract however, the activity of the carthamin-synthesizing enzyme could not be separated from that of native polyphenol oxidase or peroxidase. Partial purification of the carthamin-synthesizing enzyme could be achieved by filtration of a crude extract through Sephadex G-100 gel after treating it with ammonium sulfate, calcium acetate and protamine sulfate. -the purified enzyme reacted possitively with precarthamin at pH 4.8 in 50.0 mM acetate buffer. The synthesized product was identified as carthamin by checking its Rf values on silica gel plates developed with three different developing solvents and UV absorption spectral pattern in methanol. The enzyme sample was unstable on storage and stabilization of the sample was tested by applying many procedures. Carthamin-synthesizing enzyme had low affinity to celite 535. No carthamin was found in an incubation medium containing precarthamin and an authentic sample of polyphenol oxidase or peroxidase. Carthamin could not be converted to any blackish catabolites through polyphenol oxidase- or peroxidase-catalyzed oxidative reaction. Changes in the activities of three different enzymes, carthamin-synthesizing enzyme, polyphenol oxidase and peroxidase, were investigated in the extract from both etiolated and green seedlings of safflower and the data were discussed in relation to the catalytic properties of the enzymes.

  19. Influence of HCl on the NPs-CdSe synthesis prepared by the colloidal method

    Directory of Open Access Journals (Sweden)

    J. Sarmiento Arellano

    2016-08-01

    Full Text Available Cadmium selenide nanoparticles (NPs-CdSe were synthesized by colloidal route at room temperature and atmospheric pressure using cadmium chloride (CdCl2·2.5 hydrate and elemental selenium (Se as precursors. Sodium borohydride (NaBH4 was used as reducing agent to obtain Se2− ions and an aqueous solution with a NaOH and Penta sodium tripolyphosphate (STPP was used to protect Cd2+ ions. To remove the by-products generated during the chemical reaction and to promote the precipitation of NPs-CdSe, a cleaning process with an aqueous solution of HCl was performed. The HCl volume was varied from 0.2 to 1.2 ml during the cleaning process to study its effects on CdSe synthesis. The crystalline structure was analyzed by inspection of the high-resolution transmission electron microscope (HR-TEM and X-ray diffraction (XRD. This analysis showed that crystals of CdSe exhibit a face-centered cubic structure (FCC. The calculated crystallite size is 3.5 nm and increases to 4.5 nm as the HCl volume increases. The morphologies of the products were observed by SEM and TEM techniques. HRTEM images showed that NPs-CdSe synthetized to 0.8 ml are composed of a great number of homogeneous and smooth nanospheres which are not appreciable in SEM but are observable in TEM. By contrast, 0.2 and 1.2 ml HCl samples are comprised of a great deal of rods of compounds of Se mixed with CdSe spheres nanostructures. This work, which did not require the use of surfactants complexes or specials environment, is considered to have advantages over other works.

  20. Preparation and characterization of carbonic anhydrase-conjugated liposomes for catalytic synthesis of calcium carbonate particles.

    Science.gov (United States)

    Maeshima, Keisuke; Yoshimoto, Makoto

    2017-10-01

    The biomimetic approach using immobilized enzymes is useful for the synthesis of structurally defined inorganic materials. In this work, carbonic anhydrase (CA) from bovine erythrocytes was covalently conjugated at 25°C to the liposomes composed of 15mol% 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine-N-(glutaryl) (NG-POPE), and the zwitterionic and anionic phospholipids with the same acyl chains as NG-POPE. For the conjugation, the carboxyl groups of liposomal NG-POPE were activated with 11mM 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and 4.6mM N-hydroxysulfosuccinimide (sulfo-NHS). The carbonic anhydrase-conjugated liposomes (CALs) with the mean hydrodynamic diameter of 149nm showed the esterase activity corresponding to on average 5.5×102 free CA molecules per liposome. On the other hand, the intrinsic fluorescence and absorbance measurements consistently revealed that on average 1.4×103 CA molecules were conjugated to a liposome, suggesting that the molecular orientation of enzyme affected its activity. The formation of calcium carbonate particles was significantly accelerated by the CALs ([lipid]=50μ M) in the 0.3M Tris solution at 10-40°C with dissolved CO2 (≈17mM) and CaCl2 (46mM). The anionic CALs were adsorbed with calcium as revealed with the ζ-potential measurements. The CAL system offered the calcium-rich colloidal interface where the bicarbonate ions were catalytically produced by the liposome-conjugated CA molecules. The CALs also functioned in the external loop airlift bubble column operated with a model flue gas (10vol/vo% CO2), yielding partly agglomerated calcium carbonate particles as observed with the scanning electron microscopy (SEM). Copyright © 2017 Elsevier Inc. All rights reserved.

  1. A STUDY OF THE SYNTHESIS OF VERATRYL CYANIDE REQUIRED AS AN INTERMEDIATE FOR THE PREPARATION OF C-9154 ANTIBIOTIC DERIVATIVE FROM VANILIN

    OpenAIRE

    Ila Rosilawati; Jumina Jumina; M. Muchalal

    2010-01-01

    The synthesis of veratryl cyanide [1-(3,4-dimethoxy phenyl acetonitril] required as an intermediate for the preparation of C-9154 antibiotic derivative was carried out. The starting material used was vanilin, while the reaction steps consisted of (1) methylation of vanilin, (2) reduction of veratraldehyde, (3) synthesis of veratryl bromide, and (4) treatment of this bromide with KCN. The analysis of the products was carried out using IR, 1H NMR and GC-MS spectrophotometers.          ...

  2. Synthesis of the metastable α-Al1.8Fe0.2O3 solid solution from precursors prepared by combustion

    OpenAIRE

    Cordier, Anne; Peigney, Alain; De Grave, Eddy; Flahaut, Emmanuel; Laurent, Christophe

    2006-01-01

    The aim of the paper is to synthesise α-Al1.8Fe0.2O3 solid solutions from precursors prepared by the nitrate/fuel combustion synthesis route, using either citric acid or urea, or a mixture of both as the fuel, and different fuel/nitrates ratios. In a first part, global reactions are proposed for each synthesis, which are useful to explain the differences in powder volume, morphology, crystallisation state and specific surface area reported in the second part of the study. In a third part, the...

  3. Efficient Synthesis of β-Aryl-γ-lactams and Their Resolution with (S-Naproxen: Preparation of (R- and (S-Baclofen

    Directory of Open Access Journals (Sweden)

    Iris J. Montoya-Balbás

    2015-12-01

    Full Text Available An efficient synthesis of enantiomerically-pure β-aryl-γ-lactams is described. The principal feature of this synthesis is the practical resolution of β-aryl-γ-lactams with (S-Naproxen. The procedure is based on the Michael addition of nitromethane to benzylidenemalonates, which was easily obtained, followed by the reduction of the γ-nitroester in the presence of Raney nickel and the subsequent saponification/decarboxylation reaction. The utility of this methodology was highlighted by the preparation of enantiomerically-pure (R- and (S-Baclofen hydrochloride.

  4. Influence of double promotion on HDS catalysts prepared by urea-matrix combustion synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Cortes, Sergio L. [Laboratorio de Cinetica y Catalisis, Departamento de Quimica, Facultad de Ciencias, Universidad de Los Andes, Merida 5101 (Venezuela); Xiao, Tian-Cun; Lin, Tsung-Wu; Green, Malcolm L.H. [Wolfson Catalysis Centre, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR (United Kingdom)

    2006-04-11

    The stringent environmental regulations in the US, Japan and Europe are requiring significant improvement in the quality of transportation fuels. A new strategy based on urea-matrix combustion method for the synthesis of alumina-supported molybdate-based mixed oxides (i.e., bimetallic and trimetallic oxides) has been applied. This permits to control the alumina-mixed oxide interaction and therefore the HDS catalytic behaviour. The oxidic and sulfurized states of the HDS catalysts were characterized by X-ray diffraction (XRD), laser Raman spectroscopy (LRS), temperature-programmed reduction (TPR) and high resolution transmission electron microscopy (HRTEM). Catalyst performance was evaluated using a tubular fixed-bed reactor and the hydrodesulfurization of thiophene under normal pressure as model reaction. It has been found that Ni-promoted alumina-supported MoO{sub 3} catalyst precursor presented a non well-ordered structure of Ni-Mo phase supported on alumina surface. However, when cobalt was added to Ni-Mo precursor the {beta}-isomorph stability was significantly improved and the formation of alumina-supported {beta}-Co{sub 0.5}Ni{sub 0.5}MoO{sub 4} was observed. The activation treatments markedly affect the catalyst structure and hence the HDS catalytic performance. The catalyst series pretreated in H{sub 2}S-H{sub 2} was 2-3 times more active than those C{sub 4}H{sub 4}S-H{sub 2}-pretreated catalysts and ca. 2-10 times more active than the pre-reduced samples. A significantly greater HDS activity of H{sub 2}S-H{sub 2}-pretreated Co{sub 0.5}Mg{sub 0.5}MoS{sub x}/{gamma}-Al{sub 2}O{sub 3} catalyst was observed, which is attributed to the fact that both promoters are into the same network interacting directly with the molybdenum. This feature hinders not only the segregation of cobalt sulfide, but also the formation of long MoS{sub 2} slabs. (author)

  5. Synthesis of vinyl polymer-silica colloidal nanocomposites prepared using commercial alcoholic silica sols.

    Science.gov (United States)

    Percy, M J; Amalvy, J I; Randall, D P; Armes, S P; Greaves, S J; Watts, J F

    2004-03-16

    The surfactant-free synthesis of vinyl polymer-silica nanocomposite particles has been achieved in aqueous alcoholic media at ambient temperature in the absence of auxiliary comonomers. Styrene, methyl methacrylate, methyl acrylate, n-butyl acrylate, and 2-hydroxypropyl methacrylate were homopolymerized in turn in the presence of three commercially available ultrafine alcoholic silica sols. Stable colloidal dispersions with reasonably narrow size distributions were obtained, with silica contents of up to 58% by mass indicated by thermogravimetric analysis. Particle size distributions were assessed using both dynamic light scattering and disk centrifuge photosedimentometry. The former technique indicated that the particle size increased for the first 1-2 h at 25 degrees C and thereafter remained constant. Particle morphologies were studied using electron microscopy. Most of the colloidal nanocomposites comprised approximately spherical particles with relatively narrow size distributions, but in some cases more polydisperse or nonspherical particles were obtained. Selected acrylate-based nanocomposites were examined in terms of their film formation behavior. Scanning electron microscopy studies indicated relatively smooth films were obtained on drying at 20 degrees C, with complete loss of the original particle morphology. The optical clarity of solution-cast 10 microm nanocomposite films was assessed using visible absorption spectrophotometry, with 93-98% transmission being obtained from 400 to 800 nm; the effect of long-term immersion of such films in aqueous solutions was also examined. X-ray photoelectron spectroscopy studies indicated that the surface compositions of these nanocomposite particles are invariably silica-rich, which is consistent with their long-term colloidal stability and also with aqueous electrophoresis measurements. FT-IR studies suggested that in the case of the poly(methyl methacrylate)-silica nanocomposite particles, the carbonyl ester

  6. Visible-Light Photodegradation of Dye on Co-Doped Titania Nanotubes Prepared by Hydrothermal Synthesis

    Directory of Open Access Journals (Sweden)

    Jung-Pin Wang

    2012-01-01

    Full Text Available Highly porous Co-doped TiO2 nanotubes synthesized from a hydrothermal treatment were used to photodecompose methylene blue (MB in liquid phase under visible light irradiation. The anatase-type titania nanotubes were found to have high specific surface areas of about 289–379 m2/g. These tubes were shown to be hollow scrolls with outer diameter of about 10–15 nm and length of several micrometers. UV absorption confirmed that Co doping makes the light absorption of nanotubes shift to visible light region. With increasing the dopant concentration, the optical band gap of nanotubes became narrower, ranging from 2.4 eV to 1.8 eV, determined by Kubelka-Munk plot. The Co-doped nanotubes exhibit not only liquid-phase adsorption ability, but also visible-light-derived photodegradation of MB in aqueous solution. The synergetic effect involves two key factors in affecting the photocatalytic activity of Co-doped titania nanotubes under fluorescent lamp, that is, high porosity and optical band gap. The merit of the present work is to provide an efficient route for preparing Co-doped TiO2 nanotubes and to clarifying their adsorption and photocatalytic activity under fluorescent lamp.

  7. Synthesis and micowave characterization of conductive polyaniline prepared by continous polymerization process

    Science.gov (United States)

    Manaf, A.; Bimantoro, A.; Hafizah, M. AE; Andreas

    2017-07-01

    Results of synthesized polyaniline (PANi) prepared by a continuous polymerization process is reported. The purpose of this research is to obtain material absorber which maximum absorption. FTIR spectrum for synthesized PANi showed no double bond absorption peak at 3442 cm-1 which indicates the polymer chain was formed through repetition of single bonds. The results of the electrical conductivity measurement showed the value 17.5 μS/cm for synthesized PANI. The value increased dramatically to 3600, 1520 and 920 μS/cm after the addition of photonic acids of HClO4, H2SO4 and HCl respectively. Those values were obtained through sequences process. Results of particle size distribution confirmed that all synthesized PANi have nanoparticles. In addition, all synthesized PANi have shown electromagnetic wave absorbing properties in the frequency range 12-18 GHz. The best peak Reflection Loss (RL) values -10 dB (˜ 68 % absorption) and -25 dB (˜ 84 %) at 13 and 16.5 GHz respectively obtained on the PANi Emeraldine base (PANi-EB).

  8. Facile synthesis of phosphatidyl saccharides for preparation of anionic nanoliposomes with enhanced stability.

    Directory of Open Access Journals (Sweden)

    Shuang Song

    Full Text Available Physical stability during storage and against processing such as dehyration/rehydration are the cornerstone in designing delivery vehicles. In this work, mono-, di- and tri-saccharides were enzymatically conjugated to phosphatidyl group through a facile approach namely phospholipase D (PLD mediated transphosphatidylation in a biphasic reaction system. The purified products were structurally identified and the connectivities of carbohydrate to phosphatidyl moiety precisely mapped by (1H, (31P, (13C NMR pulse sequences and LC-ESI-FTMS. The synthetic phosphatidyl saccharides were employed as the sole biomimetic component for preparation of nanoliposomes. It was found that the critical micelle concentration (CMC of phosphatidyl saccharides increases as more bulky sugar moiety (mono- to tri- is introduced. Phosphatidyl di-saccharide had the largest membrane curvature. In comparison to the zwitterionic phosphatidylcholine liposome, all phosphatidyl saccharides liposomes are anionic and demonstrated significantly enhanced stability during storage. According to the confocal laser scan microscopy (CLSM and atom force microscopy (AFM analyses, the nanoliposomes formed by the synthetic phosphatidyl saccharides also show excellent stability against dehydration/rehydration process in which most of the liposomal structures remained intact. The abundance hydroxyl groups in the saccharide moieties might provide sufficient H-bondings for stabilization. This work demonstrated the synthesized phosphatidyl saccharides are capable of functioning as enzymatically liable materials which can form stable nanoliposomes without addition of stabilizing excipients.

  9. Synthesis and characterization of PVK/AgNPs nanocomposites prepared by laser ablation.

    Science.gov (United States)

    Abd El-Kader, F H; Hakeem, N A; Elashmawi, I S; Menazea, A A

    2015-03-05

    Nanocomposites of Poly (n-vinylcarbazole) PVK/Ag nanoparticles were prepared by laser ablation of a silver plate in aqueous solution of chlorobenzene. The influences of laser parameters such as; time of irradiation, source power and wavelength (photon energy) on structural, morphological and optical properties have been investigated using X-ray diffraction (XRD), Transmission electron microscopy (TEM), Ultraviolet-visible (UV-Vis) and Photoluminescence (PL). A correlation between the investigated properties has been discussed. XRD, TEM and PL indicated that the complexation between AgNPs and PVK in the composite system is possible. Only the reflection peak at 2θ=38° of AgNPs appeared in the composite nanoparticles while the other reflection peaks were destroyed. The nanoparticles shape and size distribution were evaluated from TEM images. TEM analysis revealed a lower average particle size at long laser irradiation time 40min and short laser wavelength 532nm together with high laser power 570mW. From UV-Visible spectra the values of absorption coefficient, absorption edge and energy tail were calculated. The reduction of band tail value with increasing the laser ablation parameters confirms the decrease of the disorder in such composite system. The PL and UV-Vis. spectra confirm that nanocomposite samples showed quantum confinement effect. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Synthesis, characterization and photocatalytic activity of ZnO nanoparticles prepared by biological method

    Science.gov (United States)

    Anbuvannan, M.; Ramesh, M.; Viruthagiri, G.; Shanmugam, N.; Kannadasan, N.

    2015-05-01

    Zinc oxide have been produced via a simple green method from zinc nitrate and leaf extract aqueous solutions. Prepared ZnO nanoparticles (NPs) were investigated by employing through UV-Visible diffuse reflectance spectroscopy (UV-DRS), photoluminescence (PL) spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR), field emission-scanning electron microscope (FE-SEM), and transmission electron microscope (TEM), respectively. The present investigation, confirmed the estimated band gap 3.51 eV and the PL intensity at 402 nm in visible region are dependent upon the geometrical shape and size of the ZnO NPs. The TEM micrograph and XRD pattern confirmed the hexagonal wurtzite structure of ZnO NPs. The presence of functional groups and the chemical bonding are confirmed by FTIR spectra. EDS shows that the highly pure ZnO nanostructures. Moreover, the catalytic activity of synthesized ZnO in the reduction of methylene blue was studied by UV-Vis spectroscopy. The effects of process conditions on the morphology and size of ZnO have been found from FE-SEM and TEM analyses, respectively.

  11. Compressible and monolithic microporous polymer sponges prepared via one-pot synthesis

    Science.gov (United States)

    Lim, Yoonbin; Cha, Min Chul; Chang, Ji Young

    2015-01-01

    Compressible and monolithic microporous polymers (MPs) are reported. MPs were prepared as monoliths via a Sonogashira–Hagihara coupling reaction of 1,3,5-triethynylbenzene (TEB) with the bis(bromothiophene) monomer (PBT-Br). The polymers were reversibly compressible, and were easily cut into any form using a knife. Microscopy studies on the MPs revealed that the polymers had tubular microstructures, resembling those often found in marine sponges. Under compression, elastic buckling of the tube bundles was observed using an optical microscope. MP-0.8, which was synthesized using a 0.8:1 molar ratio of PBT-Br to TEB, showed microporosity with a BET surface area as high as 463 m2g–1. The polymer was very hydrophobic, with a water contact angle of 145° and absorbed 7–17 times its own weight of organic liquids. The absorbates were released by simple compression, allowing recyclable use of the polymer. MPs are potential precursors of structured carbon materials; for example, a partially graphitic material was obtained by pyrolysis of MP-0.8, which showed a similar tubular structure to that of MP-0.8. PMID:26534834

  12. Antibacterial continuous nanofibrous hybrid yarn through in situ synthesis of silver nanoparticles: preparation and characterization.

    Science.gov (United States)

    Barani, Hossein

    2014-10-01

    Nanofibrous hybrid yarns of polyvinyl alcohol (PVA) and poly-l-lactide acid (PLLA) with the antibacterial activity were prepared that contains 0, 5, 10, 20, and 30 wt.% of silver nanoparticles according to the PVA polymer content. This was performed by electrospinning using distilled water and 2, 2, 2-trifluoroethanol as a solvent for PVA and PLLA respectively, and sodium borohydride was used as a reducing agent. The scanning electron microscope observation confirmed the formation of AgNPs into the PVA nanofiber structure, and they were uniform, bead free, cylindrical and smooth. The diameter of hybrid yarns and their nanofiber component was decreased as the silver nitrate concentration in electrospinning solutions was increased. The differential scanning calorimetry results indicated that the silver nanoparticles can form interactions with polymer chains and decrease the melting enthalpy. The mechanical analysis showed a lower stress and strain at break of the AgNP-loaded nanofibrous hybrid yarns than the unloaded hybrid yarn. However, there wasn't a statistically significant difference between the strain at break of electrospun nanofibrous hybrid yarns. Moreover, the bactericidal efficiency of all loaded samples was over 99.99%. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Molecular modeling, FTIR spectral characterization and mechanical properties of carbonated-hydroxyapatite prepared by mechanochemical synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Youness, Rasha A. [Spectroscopy Department, National Research Centre, El-Bohouth Str., 12622, Dokki, Giza (Egypt); Taha, Mohammed A. [Solid-State Physics Department, National Research Centre, El-Bohouth Str., 12622, Dokki, Giza (Egypt); Elhaes, Hanan [Physics Department, Faculty of Women for Arts, Science, and Education, Ain Shams University, 11757 Cairo (Egypt); Ibrahim, Medhat, E-mail: medahmed6@yahoo.com [Spectroscopy Department, National Research Centre, El-Bohouth Str., 12622, Dokki, Giza (Egypt)

    2017-04-01

    Nanocrystalline B-type carbonate substituted hydroxyapatite (B-CHA) powder has been successively synthesized by mechanochemical method. The effect of milling times on the formation of B-CHA was investigated by Fourier transform infrared spectroscopy, X-ray diffraction technique and scanning electron microscopy. Moreover, physical as well as mechanical properties were examined as a function of milling time. Furthermore, theoretical model was presented for hydroxyapatite (HA). Semiempirical calculations at PM6 level were used to calculate thermal parameters including entropy; enthalpy; heat capacity; free energy and heat of formation in the temperature range from 200 up to 500 k. The results revealed that single phase B-CHA was successfully formed after 8 h of milling when Ball to Powder Ratio (BPR) equals to 10:1. Results revealed that entropy; enthalpy and heat capacity gradually increased as a function of temperature while, free energy and heat of formation decreased with the increasing of temperature. Comparison with higher level of theory was conducted at HF and DFT using the models HF/3-21g**; B3LYP/6-31G(d,p) and B3LYP/LANL2DZ, respectively and indicated that PM6 could be utilized with appropriate accuracy and time to study physical and thermochemical parameters for HA. - Highlights: • Preparation of Nanocrystalline B-type carbonate substituted hydroxyapatite (B-CHA) powder by mechanochemical method. • Characterization of CHA. • Semiemperical and DFT models for CHA.

  14. Synthesis, structural characterization and scalable preparation of new amino-zinc borates.

    Science.gov (United States)

    Imer, M R; González, M; Veiga, N; Kremer, C; Suescun, L; Arizaga, L

    2017-11-02

    Zinc borates are very important industrial materials with applications that include fire retardants and preservatives in wood. In this work, we report the preparation of three novel zinc borates: [Zn(NH3)3B4O5(OH)4]·H2O (ZB1), Zn3(H2B3O7)2·2NH3·4H2O (ZB2), and [Zn(NH3)4][B4O5(OH)4]·4H2O (ZB3). The solid phases were characterized by elemental analysis, X-ray diffraction, infrared and Raman spectroscopy, scanning electron microscopy and thermal analysis. The crystal structures of ZB1 (monoclinic, Cc, a = 12.1972(8), b = 7.8314(5), c = 12.1441(8) Å and β = 107.404(5)°) and ZB3 (orthorhombic, Pbca, a = 15.0796(9), b = 11.8853(5) and c = 16.7606(8) Å) were determined. They are novel neutral Zn-polyborate complexes [Zn(NH3)3B4O5(OH)4] hydrate and [Zn(NH3)4][B4O5(OH)4] tetrahydrate salt, respectively. The complete assignment of infrared and Raman spectra was performed theoretically using DFT calculations. For ZB2 (obtained as a polycrystalline phase), powder X-ray diffraction confirmed a single phase and allowed the determination of the unit cell parameters and lattice type (rhombohedral, a = 36.78076 (6), c = 12.20052 (3) Å) with an expected formula Zn3(H2B3O7)2·2NH3·4H2O suggesting that this compound is a complex triborate. Furthermore, a low-cost scalable synthetic procedure for ZB1 starting from zinc oxide and boric acid in ammonia solution with a high yield is also reported.

  15. Synthesis and melt processing of cellulose esters for preparation of thermoforming materials and extended drug release tablets.

    Science.gov (United States)

    Virtanen, Sanna; Talja, Riku; Vuoti, Sauli

    2017-12-01

    Using softwood pulp as the starting material, the synthesis of regioselectively substituted mixed cellulose esters with varying degree of substitution and ratio of short/long chains was successfully completed. The structures of the cellulose esters were characterised. The impact of the structural changes and the degree of substitution of the cellulose esters on thermal properties and processability were investigated. The study shows that the sequential esterification is a promising modification route for cellulose to improve its thermal processability and mechanical properties without the use of external processing aids such as plasticisers. In particular, the hexanoate group in the C6 position on the cellulose backbone acts as an internal plasticiser and improves thermal processability and increases the strength and stiffness of the cellulose ester. The properties of sequentially esterified cellulose promote its practical use in plastics, coatings, films and drug delivery. Sequentially esterified cellulose hexanoate-acetate was used successfully in a coating formulation for the preparation of tablets and showed a stable extended release profile for three water-insoluble drugs in this context. The pH of the release medium had no notable effect on the release properties. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Environmentally-Friendly Synthesis of Carbonate-Type Macrodiols and Preparation of Transparent Self-Healable Thermoplastic Polyurethanes

    Directory of Open Access Journals (Sweden)

    Seon-Mi Kim

    2017-11-01

    Full Text Available Carbonate-type macrodiols synthesized by base-catalyzed polycondensation of co-diols and dimethyl carbonate as an environmentally-friendly route were subsequently utilized for the preparation of transparent and self-healable thermoplastic polyurethanes (TPUs containing a carbonate-type soft segment. Three types of macrodiols, obtained from mono, dual and triple diol-monomers for target molecular weights of 1 and 1.5 kg mol−1, were analyzed by 1H NMR integration and the OH titration value. Colorless transparent macrodiols in a liquid state at a room temperature of 20 °C were obtained, except the macrodiol from mono 1,6-hexanediol. Before TPU synthesis, macrodiols require pH neutralization to prevent gelation. TPUs synthesized by a solution pre-polymer method with 4,4′-methylene(bisphenyl isocyanate and 1,4-butanediol as a chain extender exhibited moderate molecular weights, good transparencies and robust mechanical properties. Especially, the incorporation of 3-methyl-1,5-pentanediol within carbonate-type macrodiols enhanced the transparency of the resultant TPUs by decreasing the degree of microphase separation evidenced by ATR-FTIR and DSC. Interestingly, packing density of hard segments and the degree of microphase separation determined the self-healing efficiency of TPUs, which showed good performances in the case of sourced macrodiols from triple diol-monomers.

  17. Fast and facile preparation of CTAB based gels and their applications in Au and Ag nanoparticles synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Upadhyay, Ravi Kant, E-mail: rkupadhyay85@gmail.com [Department of Chemistry, School of Natural Sciences, Shiv Nadar University, Gautam Budh Nagar, 201314 Uttar Pradesh (India); Soin, Navneet, E-mail: n.soin@bolton.ac.uk [Knowledge Centre for Materials Chemistry (KCMC), Institute for Materials Research and Innovation (IMRI), University of Bolton, Deane Road, Bolton BL3 5AB (United Kingdom); Saha, Susmita, E-mail: ssaha@bose.res.in [Department of Condensed Matter Physics and Material Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098 (India); Barman, Anjan, E-mail: abarman@bose.res.in [Department of Condensed Matter Physics and Material Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098 (India); Sinha Roy, Susanta, E-mail: susanta.roy@snu.edu.in [Department of Physics, School of Natural Sciences, Shiv Nadar University, Gautam Budh Nagar, 201314 Uttar Pradesh (India)

    2015-04-15

    We have demonstrated that the gel-like mesophase of Cetyltrimethylammonium bromide (CTAB) can be synthesized by judicial adjustment of water to surfactant molar ratio (W{sub 0}), without using any additional salts, gelating agents or co-surfactants. Gel formation was found to be highly dependent on the water to surfactant molar ratio (W{sub 0}), with the lowest value of W{sub 0} (41.5) resulting in rapid gel formation. Environmental scanning electron microscope (ESEM) analysis revealed that the gel was comprised of interconnected cylindrical structures. The presence of hydrogen bonding in the gel-like mesophase was confirmed by Fourier Transform Infrared spectroscopy (FTIR) analysis. Rheology measurements revealed that all the gel samples were highly viscoelastic in nature. Furthermore, Au and Ag containing CTAB gels were explored as precursors for the preparation of spherical Gold (Au) and Silver (Ag) nanoparticles using Sodium borohydride (NaBH{sub 4}) as reducing agent. The effects of NaBH{sub 4} concentration on the particle size and morphology of the Au and Ag nanoparticles have also been studied. - Highlights: • A facile synthesis of CTAB based gel-like mesophase is reported. • CTAB gels were obtained by adjusting water to surfactant molar ratio (W{sub 0}). • FTIR analysis revealed that hydrogen bonding plays a key role in gel formation. • Au, Ag nanoparticles were synthesized by using CTAB gel and NaBH{sub 4}.

  18. Formation of fatty acids in photochemical conversions of saturated hydrocarbons

    Science.gov (United States)

    Telegina, T. A.; Pavlovskaya, T. Y.; Ladyzhenskaya, A. I.

    1977-01-01

    Abiogenic synthesis of fatty acids was studied in photochemical conversions of saturated hydrocarbons. It was shown that, in a hydrocarbon water CaCO3 suspension, the action of 254 nm UV rays caused the formation of fatty acids with a maximum number of carbon atoms in the chain not exceeding that in the initial hydrocarbon. Synthesis of acetic, propionic, butyric, valeric, caproic, enanthic and caprylic (in the case of octane) acids occurs in heptane water CaCO3 and octane water CaCO3 systems.

  19. A convenient preparation of N (ε)-methyl-L-lysine derivatives and its application to the synthesis of histone tail peptides.

    Science.gov (United States)

    Chi, Hongfang; Islam, Md Shahidul; Nsiama, Tienabe K; Kato, Tamaki; Nishino, Norikazu

    2014-05-01

    A convenient route is established for the preparation of N (α)-Fmoc-N (ε)-(Boc, methyl)-L-lysine and N (α)-Fmoc-N (ε)-dimethyl-L-lysine as building blocks to be used for the synthesis of methylated peptides. This methodology is based on the use of malonate derivatives and dibromobutane to produce key intermediates, L-2-amino-6-bromohexanoic acid derivatives, which could be modified to the required group at the ε-position. Fmoc-protection is accessible, so these compounds can be used in solution as well as in solid-phase peptide synthesis. Also the peptides containing these methylated lysines have been proved to resist the action of trypsin and lysyl endopeptidase. Thus, this new method could be considered as an improvement of the synthesis of N (ε)-methyl-L-lysine derivatives.

  20. Divergent mechanisms of iron-containing enzymes for hydrocarbon biosynthesis.

    Science.gov (United States)

    Wise, Courtney E; Grant, Job L; Amaya, Jose A; Ratigan, Steven C; Hsieh, Chun H; Manley, Olivia M; Makris, Thomas M

    2017-04-01

    Increasing levels of energy consumption, dwindling resources, and environmental considerations have served as compelling motivations to explore renewable alternatives to petroleum-based fuels, including enzymatic routes for hydrocarbon synthesis. Phylogenetically diverse species have long been recognized to produce hydrocarbons, but many of the enzymes responsible have been identified within the past decade. The enzymatic conversion of Cn chain length fatty aldehydes (or acids) to Cn-1 hydrocarbons, alkanes or alkenes, involves a C-C scission reaction. Surprisingly, the enzymes involved in hydrocarbon synthesis utilize non-heme mononuclear iron, dinuclear iron, and thiolate-ligated heme cofactors that are most often associated with monooxygenation reactions. In this review, we examine the mechanisms of several enzymes involved in hydrocarbon biosynthesis, with specific emphasis on the structural and electronic changes that enable this functional switch.

  1. The Synthesis, Characterization and Catalytic Reaction Studies of Monodisperse Platinum Nanoparticles in Mesoporous Oxide Materials

    Energy Technology Data Exchange (ETDEWEB)

    Rioux, Robert M. [Univ. of California, Berkeley, CA (United States)

    2006-01-01

    A catalyst design program was implemented in which Pt nanoparticles, either of monodisperse size and/or shape were synthesized, characterized and studied in a number of hydrocarbon conversion reactions. The novel preparation of these materials enables exquisite control over their physical and chemical properties that could be controlled (and therefore rationally tuned) during synthesis. The ability to synthesize rather than prepare catalysts followed by thorough characterization enable accurate structure-function relationships to be elucidated. This thesis emphasizes all three aspects of catalyst design: synthesis, characterization and reactivity studies. The precise control of metal nanoparticle size, surface structure and composition may enable the development of highly active and selective heterogeneous catalysts.

  2. Combining Organometallic Reagents, the Sulfur Dioxide Surrogate DABSO, and Amines: A One-Pot Preparation of Sulfonamides, Amenable to Array Synthesis**

    Science.gov (United States)

    Deeming, Alex S; Russell, Claire J; Willis, Michael C

    2015-01-01

    We describe a method for the synthesis of sulfonamides through the combination of an organometallic reagent, a sulfur dioxide equivalent, and an aqueous solution of an amine under oxidative conditions (bleach). This simple reaction protocol avoids the need to employ sulfonyl chloride substrates, thus removing the limitation imposed by the commercial availability of these reagents. The resultant method allows access to new chemical space, and is also tolerant of the polar functional groups needed to impart favorable physiochemical properties required for medicinal chemistry and agrochemistry. The developed chemistry is employed in the synthesis of a targeted 70 compound array, prepared using automated methods. The array achieved a 93 % success rate for compounds prepared. Calculated molecular weights, lipophilicities, and polar surface areas are presented, demonstrating the utility of the method for delivering sulfonamides with drug-like properties. PMID:25431118

  3. Preparation, characterization, and applications of a novel solid-phase microextraction fiber by sol-gel technology on the surface of stainless steel wire for determination of poly cyclic aromatic hydrocarbons in aquatic environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Es-haghi, Ali, E-mail: a.eshaghi@rvsri.ac.ir [Department of Physico Chemistry, Razi Vaccine and Serum Research Institute, PO Box 31975/148, Karaj (Iran, Islamic Republic of); Hosseininasab, Valiallah; Bagheri, Habib [Environmental and Bio-Analytical Laboratories, Department of Chemistry, Sharif University of Technology, PO Box 11365-9516, Tehran (Iran, Islamic Republic of)

    2014-02-01

    Highlights: • A novel solid-phase microextraction (SPME) fiber was prepared using sol–gel technology. • Sol–gel coating was performed on stainless steel substrate. • The new fibers are robust and unbreakable with temperature stability. • The fibers were used for extraction of PAHs from aqueous samples. Abstract: A novel solid-phase microextraction(SPME) fiber was prepared using sol–gel technology with ethoxylated nonylphenol as a fiber coating material. The fiber was employed to develop a headspace SPME–GC–MS method suitable for quantification of 13 polycyclic aromatic hydrocarbons (PAHs) in water samples. Surface characteristics of the fibers were inspected by energy dispersive X-ray (EDX) spectroscopy as well as by scanning electron microscopy (SEM). The SEM measurements showed the presence of highly porous nano-sized particles in the coating. Important parameters affecting the extraction efficiency such as extraction temperature and time, desorption conditions as well as ionic strength have been evaluated and optimized. In the next step, the validation of the new method have been performed, finding it to be specific in the trace analysis of PAHs, with the limit of detection (LOD) ranging from 0.01 to 0.5 μg L⁻¹ and the linear range from the respective LOD to 200 μg L⁻¹with RSD amounting to less than 8%. The thermal stability of the fibers was investigated as well and they were found to be durable at 280 °C for 345 min. Furthermore, the proposed method was successfully applied for quantification of PAHs in real water samples.

  4. Effect of the preparation conditions on the catalytic activity of calcined Ca/Al-layered double hydroxides for the synthesis of glycerol carbonate

    OpenAIRE

    Salagre, P.; Granados-Reyes, J.; Cesteros, Y.

    2017-01-01

    Effect of the preparation conditions on the catalytic activity of calcined Ca/Al-layered double hydroxides for the synthesis of glycerol carbonate DOI: 10.1016/j.apcata.2017.02.013 URL: http://www.sciencedirect.com/science/article/pii/S0926860X17300686 Filiació URV: SI Memòria The effect of the preparation conditions of several calcined Ca/Al layered double hydroxide compounds (CaAl-LDH) on the catalytic transesterification of glycerol with dimethyl carbonate to obtain glycerol...

  5. SYNTHESIS OF 6-NITRO VERATRYL ALCOHOL AND 6-NITRO VERATRALDOXIM FROM VANILIN AS INTERMEDIATES FOR THE PREPARATION OF C-9154 ANTIBIOTIC DERVATIVES

    OpenAIRE

    Jumina Jumina; Undri Rastuti; Sabirin Matsjeh

    2010-01-01

    The synthesis of 6-nitro veratryl alcohol and 6-nitro veratraldoxim from vanilin which was required as intermediates for the preparation of C-9154 antibiotic derivatives was carried out. C-9154 antibiotic is a sufficiently potent antibiotic, but so far this is produced only in low yields through microbiological processes. The reaction steps performed were (1) methylation of vanilin, (2) nitration of the methylation product, (3) reduction of the corresponding nitro compound and (4) reaction of...

  6. Synthesis of enantioenriched γ-quaternary cycloheptenones using a combined allylic alkylation/Stork–Danheiser approach: preparation of mono-, bi-, and tricyclic systems

    KAUST Repository

    Bennett, Nathan B.

    2012-01-01

    A general method for the synthesis of β-substituted and unsubstituted cycloheptenones bearing enantioenriched all-carbon γ-quaternary stereocenters is reported. Hydride or organometallic addition to a seven-membered ring vinylogous ester followed by finely tuned quenching parameters achieves elimination to the corresponding cycloheptenone. The resulting enones are elaborated to bi- and tricyclic compounds with potential for the preparation of non-natural analogs and whose structures are embedded in a number of cycloheptanoid natural products.

  7. Synthesis, Properties and Application of Glucose Coated Fe3O4 Nanoparticles Prepared by Co-precipitation Method

    Science.gov (United States)

    Sari, Ayu Y.; Eko, A. S.; Candra, K.; Hasibuan, Denny P.; Ginting, M.; Sebayang, P.; Simamora, P.

    2017-07-01

    Synthesis of glucose coated Fe3O4 magnetic nanoparticles have been successfully prepared with co-precipitation method. Raw material of natural iron-sand was obtained from Buaya River, Deliserdang, Indonesia. The milled iron-sand was dissolved in HCl (37 mole %), and stirred in 300 rpm at 70°C for 90 minutes. Glucose was added to the filtered powder with varied content of 0.01, 0.02, and 0.03 mole, and precipitated by NH3 (25 mole%). After drying process, the final product subsequently was glucose coated magnetite (Fe3O4) nanoparticles. The characterizations performed were true density measurement, FTIR, VSM, XRD, BET, and adsorbent performance by AAS. The FTIR analysis showed that M-O (bending) with M=Fe (stretching vibration) with υ = 570.92 and 401.19 cm-1. While glucose coated well on nanoparticle Fe3O4, proved by functional groups C=O (stretching), M-O (stretching) and C-H (bending) with υ = 1404.17, 570.92, and 2368.58 cm-1, respectively. Single phase of magnetite (Fe3O4) structure was determined from XRD analysis with cubic spinel structure and lattice parameter of 8.396 Å. The optimum conditions, obtained on the Fe3O4 nanoparticles with 0.01 mole of glucose addition, which has true density value of 4.57 g/cm3, magnetic saturation, M s = 35,41 emu/g, coercivity, H cJ = 83.58 Oe, average particle size = 12.3 nm and surface area = 124.88 m2/g. This type magnetic nanoparticles of glucose-coated Fe3O4 was capable to adsorbed 93.78 % of ion Pb. Therefore, the glucose-coated Fe3O4 nanoparticle is a potential candidate to be used as heavy metal removal from wastewater.

  8. Al2O3/ZrO2 (Y2O3) Prepared by Combustion Synthesis Under High Gravity

    Science.gov (United States)

    Zhang, Long; Zhao, Zhongmin; Song, Yigang; Wang, Weiguo; Liu, Hongbo

    By introducing ZrO2 (4Y) powder into the thermit, Al2O3/ZrO2 (4Y) composite ceramics of different composition and microstructures were prepared through combustion synthesis under high gravity, and the correlations of composition, microstructures and mechanical properties of composite ceramics were investigated. The results of XRD, SEM and EDS showed that Al2O3/33%ZrO2 (4Y) were composed of random-orientated rod-shaped colonies consisting of a triangular dispersion of orderly submicron-nanometer t-ZrO2 fibers, surrounded by inter-colony regions consisting of spherically-shaped micronmeter t-ZrO2 grains; meanwhile, Al2O3/45%ZrO2 (4Y) were comprised of spherically-shaped micron-meter t-ZrO2 grains. Similar to the international directionally solidified Al2O3/ZrO2 (Y2O3), the EDS results also indicated that there are no impurities, amorphous phases and grain boundaries but clean phase interfaces in two ceramic composites. Compared to the international directionally solidified Al2O3/ZrO2 (Y2O3), the increase in hardness and flexural strength of Al2O3/33%ZrO2 (4Y) in the experiment was due to small-size defect and high fracture toughness induced by compressive residual stress effect and transformation toughening mechanisms; meanwhile, high flexural strength of Al2O3/45%ZrO2 (4Y) was considered to be a result of the fine spherically-shaped t-ZrO2 grains separated from the melt under high gravity, and high fracture toughness induced by transformation toughening and micro-crack toughening mechanisms.

  9. Synthesis of NBN-Type Zigzag-Edged Polycyclic Aromatic Hydrocarbons: 1,9-Diaza-9a-boraphenalene as a Structural Motif.

    Science.gov (United States)

    Wang, Xinyang; Zhang, Fan; Schellhammer, Karl Sebastian; Machata, Peter; Ortmann, Frank; Cuniberti, Gianaurelio; Fu, Yubin; Hunger, Jens; Tang, Ruizhi; Popov, Alexey A; Berger, Reinhard; Müllen, Klaus; Feng, Xinliang

    2016-09-14

    A novel class of dibenzo-fused 1,9-diaza-9a-boraphenalenes featuring zigzag edges with a nitrogen-boron-nitrogen bonding pattern named NBN-dibenzophenalenes (NBN-DBPs) has been synthesized. Alternating nitrogen and boron atoms impart high chemical stability to these zigzag-edged polycyclic aromatic hydrocarbons (PAHs), and this motif even allows for postsynthetic modifications, as demonstrated here through electrophilic bromination and subsequent palladium-catalyzed cross-coupling reactions. Upon oxidation, as a typical example, NBN-DBP 5a was nearly quantitatively converted to σ-dimer 5a-2 through an open-shell intermediate, as indicated by UV-vis-NIR absorption spectroscopy and electron paramagnetic resonance spectroscopy corroborated by spectroscopic calculations, as well as 2D NMR spectra analyses. In situ spectroelectrochemistry was used to confirm the formation process of the dimer radical cation 5a-2(•+). Finally, the developed new synthetic strategy could also be applied to obtain π-extended NBN-dibenzoheptazethrene (NBN-DBHZ), representing an efficient pathway toward NBN-doped zigzag-edged graphene nanoribbons.

  10. Polycyclic Aromatic Compounds as Anticancer Agents: Synthesis and Biological Evaluation of Methoxy Dibenzofluorene Derivatives

    Directory of Open Access Journals (Sweden)

    Bimal Krishna Banik

    2014-08-01

    Full Text Available Synthesis of a new methoxy dibenzofluorene through alkylation, cyclodehydration and aromatization in a one-pot operation is achieved for the first time. Using this hydrocarbon, a few derivatives are prepared through aromatic nitration, catalytic hydrogenation, coupling reaction with a side chain and reduction. The benzylic position of this hydrocarbon with the side chain is oxidized and reduced. Some of these derivatives have demonstrated excellent antitumor activities in vitro. This study confirms antitumor activity depends on the structures of the molecules.

  11. A study of Cu/ZnO/Al2O3 methanol catalysts prepared by flame combustion synthesis

    DEFF Research Database (Denmark)

    Jensen, Joakim Reimer; Johannessen, Tue; Wedel, Stig

    2003-01-01

    The flame combustion synthesis of Cu/ZnO/Al2O3 catalysts for the synthesis of methanol from CO, CO2 and H2 is investigated. The oxides are generated in a premixed flame from the acetyl-acetonate vapours of Cu, Zn and Al mixed with the fuel and air prior to combustion. The flame-generated powder...

  12. Studies on the diversity, abundance and succession of hydrocarbon ...

    African Journals Online (AJOL)

    A research was carried out in a tropical region to study the population of hydrocarbon utilizers in soil polluted with oily sludge. Plots were prepared to receive treatments with neat and emulsified oily sludge. These plots were further treated with fertilizer and bioaugmented with a consortium of hydrocarbon utilizers for six ...

  13. Thraustochytrid protists degrade hydrocarbons

    Digital Repository Service at National Institute of Oceanography (India)

    Raikar, M.T.; Raghukumar, S.; Vani, V.; David, J.J.; Chandramohan, D.

    that thraustochytrids have the capability to utilize a wide range of organic nitrogen and carbon compounds for their nutrition. However, the capability of these protists to degrade hydrocarbons has not been examined so far. Hydrocarbons occur in seawater either... chromatography. (1) Gravimetry: Tarballs were extracted from experimental flasks with 10 ml of carbon tetrachloride, the extract transferred to pre- weighed Petri dish and the solvent allowed to RAIKAR et al.: THRAUSTOCHYTRID PROTISTS DEGRADE HYDROCARBONS...

  14. Preparation of the Caspase-3/-7 substrate Ac-DEVD-pNA via Solution-Phase Peptide Synthesis

    Science.gov (United States)

    Peterson, Quinn P.; Goode, David R.; West, Diana C.; Botham, Rachel C.; Hergenrother, Paul J.

    2010-01-01

    The caspase enzymes are integral to cellular inflammation and apoptotic cascades, and are commonly studied by cell biologists, medicinal chemists, and chemical biologists. In particular, the assessment of caspase enzymatic activity is a standard method to evaluate cell death pathways and novel apoptosis-modulating agents. Caspase enzymatic activity can be conveniently monitored with peptidic chromogenic or fluorogenic substrates, with certain peptide sequences imparting selectivity for certain caspases. The synthesis of these peptide substrates is typically performed via solid-phase synthesis, a method that is not ideal for production of the gram quantities needed for high-throughput screening. Described herein is a facile method for the synthesis of the Ac-DEVD-pNA caspase-3 substrate using solution-phase peptide synthesis. This protocol, involving iterative PyBOP-mediated couplings and Fmoc deprotections, is rapid, operationally simple, and can be used to generate over one gram of product. PMID:20134429

  15. Preparation of peptide thioesters through fmoc-based solid-phase peptide synthesis by using amino thioesters

    DEFF Research Database (Denmark)

    Stuhr-Hansen, N.; Wilbek, T.S.; Strømgaard, K.

    2013-01-01

    An effective procedure for the synthesis of peptide alkyl thioesters by 9-fluorenylmethoxycarbonyl (Fmoc) solid-phase peptide synthesis was developed. The free C terminus of a fully protected peptide was coupled in solution with the free amino group of an amino thioester. This furnished the fully...... protected peptide thioester, which was globally deprotected to afford the desired unprotected peptide thioester. The method is compatible with labile groups such as phosphoryl and glycosyl moieties. The synthesis of peptide alkyl thioesters by 9-fluorenylmethoxycarbonyl (Fmoc) solid-phase peptide synthesis...... (SPPS) is developed. The free C terminus of a fully protected peptide is coupled in solution with the free amino group of an amino thioester. This furnishes the fully protected peptide thioester, which can be globally deprotected to afford the desired unprotected peptide thioester....

  16. Sulfonated hydrocarbon graft architectures for cation exchange membranes

    DEFF Research Database (Denmark)

    Nielsen, Mads Møller; Jankova Atanasova, Katja; Hvilsted, Søren

    2013-01-01

    A synthetic strategy to hydrocarbon graft architectures prepared from a commercial polysulfone and aimed as ion exchange membrane material is proposed. Polystyrene is grafted from a polysulfone macroinitiator by atom transfer radical polymerization, and subsequently sulfonated with acetyl sulfate...

  17. Design and stereoselective preparation of a new class of chiral olefin metathesis catalysts and application to enantioselective synthesis of quebrachamine: catalyst development inspired by natural product synthesis.

    Science.gov (United States)

    Sattely, Elizabeth S; Meek, Simon J; Malcolmson, Steven J; Schrock, Richard R; Hoveyda, Amir H

    2009-01-28

    A total synthesis of the Aspidosperma alkaloid quebrachamine in racemic form is first described. A key catalytic ring-closing metathesis of an achiral triene is used to establish the all-carbon quaternary stereogenic center and the tetracyclic structure of the natural product; the catalytic transformation proceeds with reasonable efficiency through the use of existing achiral Ru or Mo catalysts. Ru- or Mo-based chiral olefin metathesis catalysts have proven to be inefficient and entirely nonselective in cases where the desired product is observed. In the present study, the synthesis route thus serves as a platform for the discovery of new olefin metathesis catalysts that allow for efficient completion of an enantioselective synthesis of quebrachamine. Accordingly, on the basis of mechanistic principles, stereogenic-at-Mo complexes bearing only monodentate ligands have been designed. The new catalysts provide significantly higher levels of activity than observed with the previously reported Ru- or Mo-based complexes. Enantiomerically enriched chiral alkylidenes are generated through diastereoselective reactions involving achiral Mo-based bispyrrolides and enantiomerically pure silyl-protected binaphthols. Such chiral catalysts initiate the key enantioselective ring-closing metathesis step in the total synthesis of quebrachamine efficiently (1 mol % loading, 22 degrees C, 1 h, >98% conversion, 84% yield) and with high selectivity (98:2 er, 96% ee).

  18. Ammonia Synthesis using Ti and Nb Nitride Nano-particles Prepared by Mesoporous Graphitic C3N4

    KAUST Repository

    Kumagai, Hiromu

    2015-01-22

    TiN and NbN nanoparticles were synthesized from mesoporous graphitic C3N4 (mpg-C3N4) as a reactive template and used as the catalyst for ammonia synthesis. The obtained TiN and NbN nanoparticles possess high surface areas of 299 and 275 m2 g-1, respectively, making them attractive in the use of catalysis and support. Although most of the TiN and NbN particles show no measurable activity for ammonia formation, the nanoparticles enabled an ammonia synthesis rate of 31 μmol h-1 g-cat-1 at 673 K and 0.1 MPa of synthesis gas (N2 + 3H2) for both TiN and NbN catalysts. It is evident that the formation of nanoparticles with high nitride surface area is essential for the materials to function as catalysts in ammonia synthesis. The addition of Fe to TiN enhanced the ammonia synthesis activity, whereas it had detrimental effects on the catalytic activity of NbN. The properties of these catalysts in ammonia synthesis are discussed.

  19. HYDROCARBONS RESERVES IN VENEZUELA

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Cruz, D.J.

    2007-07-01

    Venezuela is an important player in the energy world, because of its hydrocarbons reserves. The process for calculating oil and associated gas reserves is described bearing in mind that 90% of the gas reserves of Venezuela are associated to oil. Likewise, an analysis is made of the oil reserves figures from 1975 to 2003. Reference is also made to inconsistencies found by international experts and the explanations offered in this respect by the Ministry of Energy and Petroleum (MENPET) and Petroleos de Venezuela (PDVSA) regarding the changes that took place in the 1980s. In turn, Hubbert's Law is explained to determine peak production of conventional oil that a reservoir or field will reach, as well as its relationship with remaining reserves. Emphasis is placed on the interest of the United Nations on this topic. The reserves of associated gas are presented along with their relationship with the different crude oils that are produced and with injected gas, as well as with respect to the possible changes that would take place in the latter if oil reserves are revised. Some recommendations are submitted so that the MENPET starts preparing the pertinent policies ruling reserves. (auth)

  20. A pharmaceutical preparation of Salvia miltiorrhiza protects cardiac myocytes from tumor necrosis factor-induced apoptosis and reduces angiotensin II-stimulated collagen synthesis in fibroblasts.

    Science.gov (United States)

    Ling, Shanhong; Luo, Ruizhi; Dai, Aozhi; Guo, Zhixin; Guo, Ruoling; Komesaroff, Paul A

    2009-01-01

    Salvia miltiorrhiza is a medicinal herb commonly used in traditional Chinese medicine for the prevention and treatment of cardiovascular disease. This study investigated the effects of Cardiotonic Pill (CP), a pharmaceutical preparation of Salvia miltiorrhiza, on cardiac myocytes and fibroblasts with respect to the viability, proliferation, and collagen synthesis in these cells under various conditions. A cardiac myocyte line, H9c2, and primarily cultured fibroblasts from rat hearts were incubated with CP over a broad concentration range (50-800 microg/ml) under normal cultures, conditions of ischemia (serum-free culture), and stimulation by angiotensin II (AII, 100 nM), hydrogen peroxide (H(2)O(2), 50-200 microM), or tumor necrosis factor alpha (TNFalpha, 40 ng/ml) for 24-48 h. Cell growth, apoptosis, DNA and collagen synthesis, and expression of relevant genes were assessed via cell number study, morphological examination, Annexin-V staining, flow-cytometry, [(3)H]-thymidine or [(3)H]-proline incorporation assay, and Western blotting analysis. It was found that (1) at therapeutic (50 microg/ml) and double therapeutic (100 microg/ml) concentrations, CP did not significantly affect normal DNA synthesis and cell growth in these cardiac cells, while at higher (over 4-fold therapeutic) concentrations (200-800 microg/ml), CP decreased DNA synthesis and cell growth and increased cell death; (2) CP treatment (50 microg/ml) significantly inhibited TNFalpha-induced apoptosis in myocytes, with 12.3+/-1.46% cells being apoptosis in CP treatment group and 37.0+/-7.34% in the control (pSalvia miltiorrhiza preparation CP is physiologically active on cardiac cells. The actions by CP to reduce apoptotic damage in myocytes and collagen synthesis in fibroblasts may help to preserve the heart function and reduce heart failure risk. The actions by CP to inhibit DNA synthesis and cell growth, which occurred at over therapeutic doses, may weaken the ability of heart repair. Further

  1. Syngas Upgrading to Hydrocarbon Fuels Technology Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Talmadge, M.; Biddy, Mary J.; Dutta, Abhijit; Jones, Susanne B.; Meyer, Pimphan A.

    2013-03-31

    In support of the Bioenergy Technologies Office, the National Renewable Energy Laboratory (NREL) and the Pacific Northwest National Laboratory (PNNL) are undertaking studies of biomass conversion technologies to hydrocarbon fuels to identify barriers and target research toward reducing conversion costs. Process designs and preliminary economic estimates for each of these pathway cases were developed using rigorous modeling tools (Aspen Plus and Chemcad). These analyses incorporated the best information available at the time of development, including data from recent pilot and bench-scale demonstrations, collaborative industrial and academic partners, and published literature and patents. This pathway case investigates the upgrading of biomass derived synthesis gas (‘syngas’) to hydrocarbon biofuels. While this specific discussion focuses on the conversion of syngas via a methanol intermediate to hydrocarbon blendstocks, there are a number of alternative conversion routes for production of hydrocarbons through a wide array of intermediates from syngas. Future work will also consider the variations to this pathway to determine the most economically viable and risk adverse conversion route. Technical barriers and key research needs have been identified that should be pursued for the syngas to hydrocarbon pathway to be competitive with petroleum-derived gasoline, diesel and jet range blendstocks.

  2. Preparation of the caspase-3/7 substrate Ac-DEVD-pNA by solution-phase peptide synthesis.

    Science.gov (United States)

    Peterson, Quinn P; Goode, David R; West, Diana C; Botham, Rachel C; Hergenrother, Paul J

    2010-02-01

    This protocol describes the gram-scale solution-phase synthesis of the colorimetric caspase-3/7 substrate Ac-DEVD-pNA. The caspase enzymes are integral to cellular inflammation and apoptotic cascades, and are commonly studied by cell biologists, medicinal chemists and chemical biologists. In particular, the assessment of caspase enzymatic activity is a standard method to evaluate cell death pathways and new apoptosis-modulating agents. Caspase enzymatic activity can be conveniently monitored with peptidic chromogenic or fluorogenic substrates, with certain peptide sequences imparting selectivity for certain caspases. The synthesis of these peptide substrates is typically carried out by solid-phase synthesis, a method that is not ideal for production of the gram quantities needed for high-throughput screening. Described herein is a facile method for the synthesis of the Ac-DEVD-pNA caspase-3/7 substrate using solution-phase peptide synthesis. This protocol, involving iterative PyBOP-mediated couplings and Fmoc deprotections, is rapid (about 5 d), operationally simple and can be used to generate over 1 g of product at a fraction of the cost of the commercial substrate.

  3. Hydrocarbon Spectral Database

    Science.gov (United States)

    SRD 115 Hydrocarbon Spectral Database (Web, free access)   All of the rotational spectral lines observed and reported in the open literature for 91 hydrocarbon molecules have been tabulated. The isotopic molecular species, assigned quantum numbers, observed frequency, estimated measurement uncertainty and reference are given for each transition reported.

  4. Plant hydrocarbon recovery process

    Energy Technology Data Exchange (ETDEWEB)

    Dzadzic, P.M.; Price, M.C.; Shih, C.J.; Weil, T.A.

    1982-01-26

    A process for production and recovery of hydrocarbons from hydrocarbon-containing whole plants in a form suitable for use as chemical feedstocks or as hydrocarbon energy sources which process comprises: (A) pulverizing by grinding or chopping hydrocarbon-containing whole plants selected from the group consisting of euphorbiaceae, apocynaceae, asclepiadaceae, compositae, cactaceae and pinaceae families to a suitable particle size, (B) drying and preheating said particles in a reducing atmosphere under positive pressure (C) passing said particles through a thermal conversion zone containing a reducing atmosphere and with a residence time of 1 second to about 30 minutes at a temperature within the range of from about 200* C. To about 1000* C., (D) separately recovering the condensable vapors as liquids and the noncondensable gases in a condition suitable for use as chemical feedstocks or as hydrocarbon fuels.

  5. Plasma devices for hydrocarbon reformation

    KAUST Repository

    Cha, Min Suk

    2017-02-16

    Plasma devices for hydrocarbon reformation are provided. Methods of using the devices for hydrocarbon reformation are also provided. The devices can include a liquid container to receive a hydrocarbon source, and a plasma torch configured to be submerged in the liquid. The plasma plume from the plasma torch can cause reformation of the hydrocarbon. The device can use a variety of plasma torches that can be arranged in a variety of positions in the liquid container. The devices can be used for the reformation of gaseous hydrocarbons and/or liquid hydrocarbons. The reformation can produce methane, lower hydrocarbons, higher hydrocarbons, hydrogen gas, water, carbon dioxide, carbon monoxide, or a combination thereof.

  6. Organocatalytic preparation of simple β-hydroxy and β-amino esters: low catalyst loadings and gram-scale synthesis.

    Science.gov (United States)

    Jiang, Hao; Gschwend, Björn; Albrecht, Lukasz; Jørgensen, Karl Anker

    2010-11-05

    A combined amino- and N-heterocyclic carbene (NHC)-catalyzed one-pot reaction sequence for the synthesis of simple enantioenriched β-hydroxy and β-amino esters using commercially available catalysts at low catalyst loadings has been developed. The desired products were obtained in high yield and excellent enantiopurity. The generation of quaternary stereocenters and application in gram-scale synthesis were also realized, with no requirements of inert or anhydrous reaction conditions, thus making this transformation a highly practical protocol.

  7. Application of oil-swollen surfactant gels as a growth medium for metal nanoparticle synthesis, and as an exfoliation medium for preparation of graphene.

    Science.gov (United States)

    Upadhyay, Ravi Kant; Waghmare, Prashant R; Roy, Susanta Sinha

    2016-07-15

    Gel is an intermediate phase of solid and liquid, which exhibits properties of both, and this unique feature of gel has made it an excellent choice as a reaction medium for the nanomaterials synthesis. Herein, we report use of oil swollen surfactant gels as reaction medium and exfoliation medium, for the synthesis of metals (Au, Ag) nanoparticles and graphene, respectively. Confined growth of metals (Au and Ag) nanoparticles, has been achieved by exploring tween 80 based surfactant gel as a reaction medium. Au NPs prepared within tween 80 gel were found to be spherical with size ∼5nm, arranged in template micelles. Heating triggered the growth of Au nanoparticles and particles of various shapes including triangles, rods and pentagonal, were produced. Au and Ag containing tween 80 gels were found to be promising as catalysts for the nitrophenol reduction. Apart from separate synthesis of Au and Ag nanoparticles, bimetallic (Au-Ag) nanoparticles have also been synthesized by taking advantage of selective reducing property of tween 80. First time CTAB gel has been utilized as an exfoliation medium for the quick exfoliation of graphite into graphene sheets, eliminating the necessity of any external driving force such as sonication or heating, to reinforce exfoliation. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Hydrophobic benzyl amines as supports for liquid-phase C-terminal amidated peptide synthesis: application to the preparation of ABT-510.

    Science.gov (United States)

    Matsumoto, Emiko; Fujita, Yuko; Okada, Yohei; Kauppinen, Esko I; Kamiya, Hidehiro; Chiba, Kazuhiro

    2015-09-01

    C-terminal amidation is one of the most common modification of peptides and frequently found in bioactive peptides. However, the C-terminal modification must be creative, because current chemical synthetic techniques of peptides are dominated by the use of C-terminal protecting supports. Therefore, it must be carried out after the removal of such supports, complicating reaction work-up and product isolation. In this context, hydrophobic benzyl amines were successfully added to the growing toolbox of soluble tag-assisted liquid-phase peptide synthesis as supports, leading to the total synthesis of ABT-510 (2). Although an ethyl amide-forming type was used in the present work, different types of hydrophobic benzyl amines could also be simply designed and prepared through versatile reductive aminations in one step. The standard acidic treatment used in the final deprotection step for peptide synthesis gave the desired C-terminal secondary amidated peptide with no epimerization. Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd.

  9. Combining organometallic reagents, the sulfur dioxide surrogate DABSO, and amines: a one-pot preparation of sulfonamides, amenable to array synthesis.

    Science.gov (United States)

    Deeming, Alex S; Russell, Claire J; Willis, Michael C

    2015-01-19

    We describe a method for the synthesis of sulfonamides through the combination of an organometallic reagent, a sulfur dioxide equivalent, and an aqueous solution of an amine under oxidative conditions (bleach). This simple reaction protocol avoids the need to employ sulfonyl chloride substrates, thus removing the limitation imposed by the commercial availability of these reagents. The resultant method allows access to new chemical space, and is also tolerant of the polar functional groups needed to impart favorable physiochemical properties required for medicinal chemistry and agrochemistry. The developed chemistry is employed in the synthesis of a targeted 70 compound array, prepared using automated methods. The array achieved a 93% success rate for compounds prepared. Calculated molecular weights, lipophilicities, and polar surface areas are presented, demonstrating the utility of the method for delivering sulfonamides with drug-like properties. © 2014 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

  10. Characterization of hydrocarbon utilizing fungi from hydrocarbon ...

    African Journals Online (AJOL)

    Prof. Ogunji

    Microorganisms play diverse roles in biotechnology; one of such roles is ... hydrocarbon polluted sites using vapour phase transfer technique with ... The purified fungal isolates were identified based on .... Cytochrome P450 monooxygenase systems which incorporate molecular .... substrate specificity on marine bacteria.

  11. Influence of the liposomal preparation Butaintervite on protein synthesis function in the livers of rats under the influence of carbon tetrachloride poisoning

    Directory of Open Access Journals (Sweden)

    M. I. Hariv

    2016-09-01

    Full Text Available This article presents the results of research into the influence of the complex liposomal preparation Butaintervit on protein synthesis function in the livers of rats under the influence of carbon tetrachloride poisoning. Intramuscular injection of carbon tetrachloride into rats at a dose of 0.25 ml per100 gof body weight causes antigenic load on the body and leads to disruption of protein synthesis function in the liver. This is shown by reduction in blood levels of total protein and its fractions. Thus, the level of albumin in the serum of rats under the conditions of oxidative stress was 70% lower than in clinically healthy animals. However, the level of total protein in the serum was only 10% lower. This is because, along with the decrease of albumin content in the serum, the levels of globulin protein fraction increased by 8.8%. This has led to albumin/globulin disparities in the serum of sick animals. As a result, the value of A/G coefficient was 0.28 ± 0.03, compared to 0.52 ±0.02 inclinically healthy rats. For the normalization of functional state of the liver under oxidative stress it is advisable to apply the liposomal preparation Butaintervite, which in its structure contains butafosfan, interferon, thistle and vitamins A, D and E. Under conditions of oxidative stress and under the action of the liposomal preparation in the rats from the second experimental group we have found significant increase in the levels of total protein and albumins and a decrease in serum globulin in the animals on the fifth and tenth days of the experiment. On the fourteenth day of the experiment under the conditions of oxidative stress and under the action of the liposomal preparation in the rats from the second experimental group the normalization of protein synthesis function in the liver was observed. The level of indicators of total protein, albumin, globulin and the coefficient of albumin/globulin compared with the control group of animals were

  12. Synthesis of layered zinc hydroxide intercalated with dodecyl sulfate organic-inorganic hybrid nanocomposite as a fiber coating for the headspace solid-phase microextraction of aromatic hydrocarbons from water.

    Science.gov (United States)

    Yousefi, Vahid; Parastari, Sheyda; Gorji, Mohsen; Foroutani, Reza; Mahdavi, Mehri; Hazizadeh, Behzad

    2016-12-01

    We describe the synthesis of a layered zinc hydroxide-dodecyl sulfate organic-inorganic hybrid nanocomposite as a new solid-phase microextraction fiber. The fiber coating can be prepared easily in a short time and the reaction is at room temperature; it is mechanically stable and exhibits relatively high thermal stability. The synthesized layered zinc hydroxide-dodecyl sulfate nanocomposite was successfully prepared and immobilized on a stainless steel wire and evaluated for the extraction of aromatic compounds from aqueous sample solutions in combination with gas chromatography and mass spectrometry. The method yields good results for some validation parameters. Under optimum conditions (extraction time: 15 min, extraction temperature: 50°C, desorption time: 1 min, desorption temperature: 250°C, salt concentration: 0.5 g/mL), the limit of detection and dynamic linear range were 0.69-3.2 ng/L and 10-500 ng/L, respectively. The method was applied to the analyses of benzene, toluene, ethylbenzene, and o-, p-, and m-xylenes in two real water samples collected from the Aji river and Mehran river, Tabriz, Iran. Under optimum conditions, the repeatability and reproducibility for one fiber (n = 3), expressed as the relative standard deviation, was 3.2-7.3% and 4.2-11.2% respectively. The fibers are thermally stable and yield better recoveries than conventional methods of analysis. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Hydrocarbon toxicity: A review.

    Science.gov (United States)

    Tormoehlen, L M; Tekulve, K J; Nañagas, K A

    2014-06-01

    Clinical effects of hydrocarbon exposure have been reported since 1897. These substances are ubiquitous, and their exposures are common. The specific hydrocarbon and route of exposure will determine the clinical effect, and an understanding of this is helpful in the care of the hydrocarbon-exposed patient. To complete a comprehensive review of the literature on hydrocarbon toxicity and summarize the findings. Relevant literature was identified through searches of Medline (PubMed/OVID) and Cochrane Library databases (inclusive of years 1975-2013), as well as from multiple toxicology textbooks. Bibliographies of the identified articles were also reviewed. Search terms included combinations of the following: hydrocarbons, inhalants, encephalopathy, coma, cognitive deficits, inhalant abuse, huffing, sudden sniffing death, toluene, renal tubular acidosis, metabolic acidosis, arrhythmia, dermatitis, and aspiration pneumonitis. All pertinent clinical trials, observational studies, and case reports relevant to hydrocarbon exposure and published in English were reviewed. Chronic, occupational hydrocarbon toxicity was not included. Exposure to hydrocarbons occurs through one of the following routes: inhalation, ingestion with or without aspiration, or dermal exposure. Inhalational abuse is associated with central nervous system depression, metabolic acidosis, and arrhythmia. The exact mechanism of the CNS depression is unknown, but experimental evidence suggests effects on NMDA, dopamine, and GABA receptors. Chronic toluene inhalation causes a non-anion gap metabolic acidosis associated with hypokalemia. Halogenated hydrocarbon abuse can cause a fatal malignant arrhythmia, termed "sudden sniffing death". Individuals who regularly abuse hydrocarbons are more likely to be polysubstance users, exhibit criminal or violent behavior, and develop memory and other cognitive deficits. Heavy, long-term use results in cerebellar dysfunction, encephalopathy, weakness, and dementia

  14. Interfacing click chemistry with automated oligonucleotide synthesis for the preparation of fluorescent DNA probes containing internal xanthene and cyanine dyes

    DEFF Research Database (Denmark)

    Astakhova, I Kira; Wengel, Jesper

    2013-01-01

    of novel oligonucleotide probes containing internally positioned xanthene and cyanine dye pairs and thus represents a significant step forward for the preparation of advanced fluorescent oligonucleotide probes. Furthermore, we demonstrate that the novel xanthene and cyanine labeled probes display unusual...

  15. Synthesis of nonspherical superparamagnetic particles: in situ coprecipitation of magnetic nanoparticles in microgels prepared by stop-flow lithography.

    Science.gov (United States)

    Suh, Su Kyung; Yuet, Kai; Hwang, Dae Kun; Bong, Ki Wan; Doyle, Patrick S; Hatton, T Alan

    2012-05-02

    We present the synthesis of nonspherical magnetic microparticles with multiple functionalities, shapes, and chemistries. Particle synthesis was performed in two steps: polymeric microparticles functionalized homogenously with carboxyl groups were generated using stop-flow lithography, and then in situ coprecipitation was used to grow magnetic nanoparticles at these carboxyl sites. With successive growth of magnetic nanoparticles, we obtained polymeric particles with saturation magnetizations of up to 42 emu/g microparticle. The growth in the magnetic nanoparticle mean size and polydispersity was determined from the magnetization curves obtained following each growth cycle; nanoparticle sizes were limited by the physical constraint of the effective mesh within the hosting gel microparticle. Particles with spatially segregated domains of varying magnetic properties (e.g., Janus particles, particles with step changes in magnetite concentration, etc.) can be synthesized readily using this approach. © 2012 American Chemical Society

  16. Synthesis and Modular Reactivity of Pyrazole 5-Trifluoroborates: Intermediates for the Preparation of Fully-Functionalized Pyrazoles.

    OpenAIRE

    Fricero, P.; Bialy, L.; Brown, A. W.; Czechtizky, W.; Mendez, M.; Harrity, J.P.

    2017-01-01

    The regioselective condensation of hydrazines and ynone trifluoroborates provides access to a range of pyrazole 5-trifluoroborates. The stability of the borate unit allows chemoselective halogenation of the heteroaromatic ring, thereby delivering pyrazole scaffolds that allow orthogonal functionalization at C5 and C4. The modular reactivity of these intermediates is exemplified by cross-coupling reactions, enabling regiocontrolled synthesis of fully-functionalized pyrazole derivatives.

  17. Easy and fast preparation of TiO{sub 2} - based nanostructures using microwave assisted hydrothermal synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Bregadiolli, Bruna Andressa, E-mail: brunabregadiolli@fc.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Bauru, SP (Brazil); Fernandes, Silvia Leticia; Graeff, Carlos Frederico de Oliveira [Universidade Estadual Paulista de Mesquita Filho (UNESP), Araraquara, SP (Brazil)

    2017-07-15

    TiO{sub 2} derivatives with distinct morphologies have been successfully obtained by microwave assisted hydrothermal synthesis in acidic and alkaline medium using mild conditions. Titanium tetraisopropoxide (TTIP) was used as precursor in different environmental conditions under low temperatures, inferior to 150 °C, and short synthesis times, from 2 to 60 min. X ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and N{sub 2} adsorption at 77 K (BET) were used to characterize the microstructural properties of the oxides. In the acidic synthesis the reaction time and temperature are not accompanied by significant changes in the structure of the material. However, in the basic conditions, the concentration of Na{sup +} ions strongly influences the particle morphology and growth. The morphology of the nanoparticles shows irregular spheres in acidic conditions, while in alkaline medium, needle like structures are formed as well as aggregated nanotube-like structures synthesized in only 30 min. Besides the difference in the morphology and structure, in both systems, high surface area was obtained. (author)

  18. Synthesis and magnetic properties of barium-calcium hexaferrite particles prepared by sol-gel and microemulsion techniques

    Science.gov (United States)

    Jotania, R. B.; Khomane, R. B.; Chauhan, C. C.; Menon, S. K.; Kulkarni, B. D.

    The preparation of W-type hexaferrite particles with the composition BaCa 2Fe 16O 27 by microemulsion and a stearic acid sol-gel method with and without surfactant has been investigated at various sintering temperatures. The structural and magnetic characteristics have been studied by X-ray diffraction (XRD), a vibrating sample magnetometer (VSM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetric (DSC) and Fourier transform infrared (FTIR) techniques. The effect of sintering temperature on the properties of BaCa 2Fe 16O 27 hexaferrites has been studied. The value of saturation magnetization ( Ms) depends on types of surfactant used. The sample prepared in the presence of polyoxyethylene (20) sorbitan monooleat (Tween 80) shows low saturation magnetization ( Ms=15.10 emu/g), whereas the other sample prepared in the presence of a surfactant cetyltrimethylammonium bromide (CTAB) exhibits high saturation magnetization ( Ms=24.60 emu/g) compared to the normal sample.

  19. Influence of Impregnation and Coprecipitation Method in Preparation of Cu/ZnO Catalyst for Methanol Synthesis

    OpenAIRE

    Prasetyaningsih, Yusi; Hendriyana, Hendriyana; Susanto, Herri

    2016-01-01

    Cu/ZnO catalyst was succesfully prepared using a coprecipitation method. The mixing procedure of the Cu(NO3)2, Zn(NO3)2 and Na2CO3 solutions had an important influence on the characteristics of the catalyst. The best catalyst obtained was the one prepared with slow mixing of the salt solutions and a CuO/ZnO molar ratio of 50:50. This raw catalyst had a maximum surface area of about 61.6 m2/g. Increasing the CuO/ZnO molar ratio caused an agglomeration of precipitated particles, reducing the su...

  20. Novel Easy Preparations of Some Aromatic Iodine(I, III, and V Reagents, Widely Applied in Modern Organic Synthesis

    Directory of Open Access Journals (Sweden)

    Lech Skulski

    2003-01-01

    Full Text Available We report our novel (or considerably improved methods for the synthesis of aromatic iodides, (dichloroiodoarenes, (diacetoxyiodoarenes, [bis(trifluoroacetoxy-iodo]arenes, iodylarenes and diaryliodonium salts, as well as some facile, oxidative anion metatheses in crude diaryliodonium or tetraalkylammonium halides and, for comparison, potassium halides. All our formerly published papers were discussed and explained in our review “Organic Iodine(I, III, and V Chemistry: 10 Years of Development at the Medical University of Warsaw, Poland” (1990-2000 [1]. Our newest results are discussed below.

  1. CuFe2O4 magnetic heterogeneous nanocatalyst: Low power sonochemical-coprecipitation preparation and applications in synthesis of 4H-chromene-3-carbonitrile scaffolds.

    Science.gov (United States)

    Rajput, Jaspreet Kaur; Arora, Priya; Kaur, Gagandeep; Kaur, Manpreet

    2015-09-01

    The paper presents the synthesis and catalytic activity of CuFe2O4 nanoparticles. The CuFe2O4 nanoparticles have been prepared by sonochemical route under low power ultrasonic irradiation (UI) and using silent stirring at room temperature only (ST) along with co-precipitation method, without using any additive/capping agent. The synthesized magnetic nanoparticles were successfully used and compared for the synthesis of 4H-chromene-3-carbonitrile derivatives. The CuFe2O4 nanoparticles obtained by sonochemical route exhibit higher catalytic activity because of small size (0.5-5 nm), high surface area (214.55 m(2)/g), high thermal stability up to 700°C, recyclability and reusability due to its magnetic characteristics than CuFe2O4 nanoparticles obtained by room temperature silent stirring. The synthesized CuFe2O4 nanoparticles were characterized by FT-IR, SEM-EDX, HR-TEM, XRD, TGA/DTA/DTG, BET, VSM techniques. The present method is of great interest due to its salient features such as environmentally compatible, efficient, short reaction time, chemoselectivity, high yield, cheap, moisture insensitive, green and recyclable catalyst which make it sustainable protocol. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Trace detection of tetrahydrocannabinol (THC) with a SERS-based capillary platform prepared by the in situ microwave synthesis of AgNPs.

    Science.gov (United States)

    Yüksel, Sezin; Schwenke, Almut M; Soliveri, Guido; Ardizzone, Silvia; Weber, Karina; Cialla-May, Dana; Hoeppener, Stephanie; Schubert, Ulrich S; Popp, Jürgen

    2016-10-05

    In the present study, an ultra-sensitive and highly reproducible novel SERS-based capillary platform was developed and utilized for the trace detection of tetrahydrocannabinol (THC). The approach combines the advantages of microwave-assisted nanoparticle synthesis, plasmonics and capillary forces. By employing a microwave-assisted preparation method, glass capillaries were reproducibly coated with silver nanoparticles in a batch fabrication process that required a processing time of 3 min without needing to use any pre-surface modifications or add surfactants. The coated capillaries exhibited an excellent SERS activity with a high reproducibility and enabled the detection of low concentrations of target molecules. At the same time, only a small amount of analyte and a short and simple incubation process was required. The developed platform was applied to the spectroscopic characterization of tetrahydrocannabinol (THC) and its identification at concentration levels down to 1 nM. Thus, a highly efficient detection system for practical applications, e.g., in drug monitoring/detection, is introduced, which can be fabricated at low cost by using microwave-assisted batch synthesis techniques. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Preparation, characterization, and theoretical analysis of group 14 element(I) dimers: a case study of magnesium(I) compounds as reducing agents in inorganic synthesis.

    Science.gov (United States)

    Jones, Cameron; Bonyhady, Simon J; Holzmann, Nicole; Frenking, Gernot; Stasch, Andreas

    2011-12-19

    A synthetic route to the new amidine (DipNH)(DipN)C(C(6)H(4)Bu(t)-4) (ButisoH; Dip = C(6)H(3)Pr(i)(2)-2,6) has been developed. Its deprotonation with either LiBu(n) or KN(SiMe(3))(2) yields the amidinate complexes [M(Butiso)] (M = Li or K). Their reactions with group 14 element halides/pseudohalides afford the heteroleptic group 14 complexes [(Butiso)SiCl(3)], [(Butiso)ECl] (E = Ge or Sn), and [{(Butiso)Pb(μ-O(3)SCF(3))(THF)}(∞)], all of which have been crystallographically characterized. In addition, the synthesis and spectroscopic characterization of the homoleptic complex [Pb(Butiso)(2)] is reported. Reductions of the heteroleptic complexes with a soluble magnesium(I) dimer, [{((Mes)Nacnac)Mg}(2)] ((Mes)Nacnac = [(MesNCMe)(2)CH](-); Mes = mesityl), have given moderate-to-high yields of the group 14 element(I) dimers [{(Butiso)E}(2)] (E = Si, Ge, or Sn), the X-ray crystallographic studies of which reveal trans-bent structures. The corresponding lead(I) complex could not be prepared. Comprehensive spectroscopic and theoretical analyses of [{(Butiso)E}(2)] have allowed their properties to be compared. All complexes possess E-E single bonds and can be considered as intramolecularly base-stabilized examples of ditetrelynes, REER. Taken as a whole, this study highlights the synthetic utility of soluble and easy to prepare magnesium(I) dimers as valuable alternatives to the harsh, and often insoluble, alkali-metal reducing agents that are currently widely employed in the synthesis of low-oxidation-state organometallic/inorganic complexes. © 2011 American Chemical Society

  4. Antitubercular activity of ZnO nanoparticles prepared by solution combustion synthesis using lemon juice as bio-fuel.

    Science.gov (United States)

    Gopala Krishna, Prashanth; Paduvarahalli Ananthaswamy, Prashanth; Trivedi, Priyanka; Chaturvedi, Vinita; Bhangi Mutta, Nagabhushana; Sannaiah, Ananda; Erra, Amani; Yadavalli, Tejabhiram

    2017-06-01

    In this study, we report the synthesis, structural and morphological characteristics of zinc oxide (ZnO) nanoparticles using solution combustion synthesis method where lemon juice was used as the fuel. In vitro anti-tubercular activity of the synthesized ZnO nanoparticles and their biocompatibility studies, both in vitro and in vivo were carried out. The synthesized nanoparticles showed inhibition of Mycobacterium tuberculosis H37Ra strain at concentrations as low as 12.5μg/mL. In vitro cytotoxicity study performed with normal mammalian cells (L929, 3T3-L1) showed that ZnO nanoparticles are non-toxic with a Selectivity Index (SI) >10. Cytotoxicity performed on two human cancer cell lines DU-145 and Calu-6 indicated the anti-cancer activity of ZnO nanoparticles at varied concentrations. Results of blood hemolysis indicated the biocompatibility of ZnO nanoparticles. Furthermore, in vivo toxicity studies of ZnO nanoparticles conducted on Swiss albino mice (for 14days as per the OECD 423 guidelines) showed no evident toxicity. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Preparative synthesis of beta-L-malyl-coenzyme A assisted by malyl-coenzyme A synthetase from Pseudomonas AM1.

    Science.gov (United States)

    Willibald, B; Boves, H; Holler, E

    1995-05-20

    beta-L-Malyl-CoA was synthesized from L-malate, CoA, and ATP in the presence of catalytic amounts of L-malyl-CoA synthetase (thiokinase) from Pseudomona AM1, which had been 50-fold purified by protamine sulfate precipitation, ammonium sulfate precipitation, chromatography on DEAE-cellulose, and affinity chromatography on High Trap Blue in less than 2 days. The homogeneous enzyme was free of L-malyl-CoA lyase and showed 63% homology with succinyl-CoA synthetase from Thermus aquaticus in its N-terminal sequences. Yields of beta-L-[14C]malyl-CoA(1-10 mumol) were 70% before and 65% after purification in 0.1-0.5 mumol portions by high-performance liquid chromatography on a MN Nucleosil 100-7 C8 column. For most biochemical work, the product was partially purified with an overall 45% yield by chromatography on DEAE-Sephacel. The identity of the compound as beta-L-malyl-CoA was verified by chemical and enzymatic tests, and also in comparison with its chemically synthesized counterpart. The enzymatic synthesis, especially of radioactively labeled beta-L-malyl-CoA, is considerably faster, higher in yield, and less problematic than chemical synthesis.

  6. Systems Biocatalysis: Development and engineering of cell-free "artificial metabolisms" for preparative multi-enzymatic synthesis.

    Science.gov (United States)

    Fessner, Wolf-Dieter

    2015-12-25

    Systems Biocatalysis is an emerging concept of organizing enzymes in vitro to construct complex reaction cascades for an efficient, sustainable synthesis of valuable chemical products. The strategy merges the synthetic focus of chemistry with the modular design of biological systems, which is similar to metabolic engineering of cellular production systems but can be realized at a far lower level of complexity from a true reductionist approach. Such operations are free from material erosion by competing metabolic pathways, from kinetic restrictions by physical barriers and regulating circuits, and from toxicity problems with reactive foreign substrates, which are notorious problems in whole-cell systems. A particular advantage of cell-free concepts arises from the inherent opportunity to construct novel biocatalytic reaction systems for the efficient synthesis of non-natural products ("artificial metabolisms") by using enzymes specifically chosen or engineered for non-natural substrate promiscuity. Examples illustrating the technology from our laboratory are discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Nestmate recognition in social insects and the role of hydrocarbons

    DEFF Research Database (Denmark)

    van Zweden, Jelle Stijn; D'Ettorre, Patrizia

    2010-01-01

    A unique and critical analysis of the wealth of research conducted on the biology, biochemistry and chemical ecology of the rapidly growing field of insect cuticular hydrocarbons. Authored by leading experts in their respective fields, the twenty chapters show the complexity that has been...... discovered in the nature and role of hydrocarbons in entomology. Covers, in great depth, aspects of chemistry (structures, qualitative and quantitative analysis), biochemistry (biosynthesis, molecular biology, genetics, evolution), physiology, taxonomy, and ecology. Clearly presents to the reader the array...... of data, ideas, insights and historical disagreements that have been accumulated during the past half century. An emphasis is placed on the role of insect hydrocarbons in chemical communication, especially among the social insects. Includes the first review on the chemical synthesis of insect hydrocarbons...

  8. Synthesis and characterization of a novel acryl amide-based yttrium imprinted sorbent via the ATRP approach for the preparation of medical-grade {sup 90}Y

    Energy Technology Data Exchange (ETDEWEB)

    Abedi, Mahvash [Nuclear Schience and Technology Research Institute (NSTRI), Tehran (Iran, Islamic Republic of); Shahid Beheshti Univ., Tehran (Iran, Islamic Republic of). Dept. of Chemistry; Shirvani-Arani, Simindokht; Bahrami-Samani, Ali [Nuclear Schience and Technology Research Institute (NSTRI), Tehran (Iran, Islamic Republic of); Nabid, Mohammad Reza [Shahid Beheshti Univ., Tehran (Iran, Islamic Republic of). Dept. of Chemistry

    2016-05-01

    Because of its favorable radionuclidic properties (pure beta emitter, E{sub βmax} = 2.28 MeV, T{sub 1/2} = 64.1 h), the preparation of carrier free {sup 90}Y is of a great importance in radiopharmacy. Herein, we report the synthesis, characterization, and application of a novel yttrium sorbent prepared on the basis of the ion-imprinting concept. The ion-imprinted polymer (IIP) was prepared by atom transfer radical copolymerization of acryl amide (AAm, functional monomer) and N,N'-methylenebisacrylamide (MBAAm) crosslinking agent in the presence of a complex of yttrium ions (template ions) with a homemade chelator, i.e., 2,2-bis(2-bromo-2-methylpropanoate)propane-1,3-disuccinate (also as initiator). For elimination of yttrium ions, which act as the template, the prepared particles were treated with 50% v:v HCl: H{sub 2}O to produce yttrium-imprinted polymeric sorbent. To control the imprinting effect, corresponding non-imprinted particles (NIP) were prepared in a similar manner except that yttrium ions were not used. The synthesized chemicals for the preparation of the chelator-initiator compound and the product itself were assessed in every step using {sup 1}H-NMR analysis. NIP and YIP were subjected to X-ray diffraction (XRD), infra-red spectroscopy (IR) and BET surface area analysis for characterization studies. Sorption/desorption studies were conducted, and the effects of potentially interfering ions, such as Sr{sup 2+} (α = 119.69) and Zr{sup 4+} (α = 73.01) in presence of radio-yttrium, were investigated (particle size: 50-100 μm, resultant recovery of > 99% within 60 min and a capacity of 33.33 mg Y(III) per gram of sorbent). The results showed that amounts of radio-yttrium as low as 250 μg could be extracted effectively with high radionuclidic and radiochemical purity from macro-gram amounts of strontium.

  9. Radiation-induced volatile hydrocarbon production in platelets

    Energy Technology Data Exchange (ETDEWEB)

    Radha, E.; Vaishnav, Y.N.; Kumar, K.S.; Weiss, J.F.

    1989-01-01

    Generation of volatile hydrocarbons (ethane, pentane) as a measure of lipid peroxidation was followed in preparations from platelet-rich plasma irradiated in vitro. The hydrocarbons in the headspace of sealed vials containing irradiated and nonirradiated washed platelets, platelet-rich plasma, or platelet-poor plasma increased with time. The major hydrocarbon, pentane, increased linearly and significantly with increasing log radiation dose, suggesting that reactive oxygen species induced by ionizing radiation result in lipid peroxidation. Measurements of lipid peroxidation products may give an indication of suboptimal quality of stored and/or irradiated platelets.

  10. Temperature Coefficients of the Refractive Index for Complex Hydrocarbon Mixtures

    Science.gov (United States)

    Wen, Qing; Shen, Jun; Gieleciak, Rafal; Michaelian, Kirk H.; Rohling, Jurandir H.; Astrath, Nelson G. C.; Baesso, Mauro L.

    2014-05-01

    Temperature coefficients of the refractive index () in the to temperature interval for hydrocarbon mixtures containing as many as 14 compounds were investigated in this work. The measured of the mixtures were compared with calculations based on the values for each compound and their concentrations. Differences of about 1 % between measured and calculated values were observed for all mixtures. The additivity of for these hydrocarbons enables preparation of surrogate fuels that are formulated to have properties like those of specific diesel fuels.

  11. Composition controlled synthesis of PCL-PEG Janus nanoparticles: magnetite nanoparticles prepared from one-pot photo-click reaction.

    Science.gov (United States)

    Khoee, S; Bagheri, Y; Hashemi, A

    2015-03-07

    The aim of this study is to investigate the effect of polymer nature on the morphology of synthesized nanoparticles. Super paramagnetic iron oxide nanoparticles (SPIONs) were prepared by co-precipitation method and then reacted with (3-mercaptopropyl) trimethoxysilane to obtain thiol-decorated SPIONs. Acrylated poly(caprolactone) and methoxy poly(ethylene glycol) were prepared, and then "thiol-ene click" reaction was performed under UV irradiation to attach two types of polymers on the surface of magnetite nanoparticles via the "photo-click" reaction method. Computational modelling was used for the prediction of the self-assembly of polymers on the surface of SPIONs, which determines the morphology of polymer coated nanoparticles.

  12. Atom Efficient Preparation of Zinc Selenates for the Synthesis of Selenol Esters under “On Water” Conditions

    Directory of Open Access Journals (Sweden)

    Luca Sancineto

    2017-06-01

    Full Text Available We describe here an atom efficient procedure to prepare selenol esters in good to excellent yields by reacting [(PhSe2Zn] or [(PhSe2Zn]TMEDA with acyl chlorides under “on water” conditions. The method is applicable to a series of aromatic and aliphatic acyl chlorides and tolerates the presence of other functionalities in the starting material.

  13. Preparative-scale synthesis of two metabolites isolated from soil treated with zoxium fungicide and kerb herbicide.

    Science.gov (United States)

    Michelotti, Enrique L; Borrell, José I; Roemmele, Renee; Matallana, Josep L; Teixidó, Jordi; Bryman, Lois M

    2002-01-30

    The preparation in multigram scale of two metabolites 3-(3,5-dichloro-4-methyl-benzoylamino)-2-hydroxy-3-methyl-pentanoic acid and 3-(3,5-dichloro-benzoylamino)-3-methyl-2-oxo-butyric acid isolated from soil treated with either Zoxium fungicide or Kerb herbicide was efficiently accomplished using a common 5-step synthetic process starting from easily available raw materials.

  14. A new approach to prepare nanoscopic rare earth metal fluorides: the fluorolytic sol-gel synthesis of ytterbium fluoride.

    Science.gov (United States)

    Schmidt, L; Dimitrov, A; Kemnitz, E

    2014-06-25

    A new approach for the preparation of approx. 5 nm sized ytterbium fluoride nanoparticles based on the fluorolytic sol-gel route is reported. DLS, TEM, IR and XRD were used to characterize the particles as well as the aging behavior of the sols. Furthermore, a new Yb(III) complex was isolated from the precursor solution and characterized by X-ray single crystal structure determination.

  15. Stereoselective Preparation of (E)-Configured 1,2-Disubstituted Propenes from Two Aldehydes by a Two-Carbon Stitching Strategy : Convergent Synthesis of 18,21-Diisopropyl-Geldanamycin Hydroquinone and Its C7 Epimer

    NARCIS (Netherlands)

    Hampel, Thomas; Neubauer, Thomas; van Leeuwen, Thomas; Bach, Thorsten

    The title compounds were synthesized in a longest sequence of 27 linear steps and with an overall yield of 2.9 and 3.9?%. In the course of the synthesis, two aldehydes representing carbon fragments C1?C7 (Eastern fragment) and C9?C21 (Western fragment) were prepared from D-mannitol, each of which

  16. Fischer-Tropsch Synthesis over Iron Manganese Catalysts: Effect of Preparation and Operating Conditions on Catalyst Performance

    Directory of Open Access Journals (Sweden)

    Ali A. Mirzaei

    2009-01-01

    molar basis which is the most active catalyst for the conversion of synthesis gas to light olefins. The effects of different promoters and supports with loading of optimum support on the catalytic performance of catalysts are also studied. It was found that the catalyst containing 50%Fe/50%Mn/5 wt.%Al2O3 is an optimum-modified catalyst. The catalytic performance of optimal catalyst has been studied in operation conditions such as a range of reaction temperatures, H2/CO molar feed ratios and a range of total pressures. Characterization of both precursors and calcined catalysts is carried out by powder X-ray diffraction (XRD, scanning electron microscopy (SEM, BET specific surface area and thermal analysis methods such as TGA and DSC.

  17. Synthesis and characterization of c-BN films prepared by ion beam assisted deposition and triode sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Ben el Mekki, M.; Djouadi, M.A.; Mortet, V.; Guiot, E. [ENSAM, Cluny (France). Lab. Bourguignon des Mater. et Procedes; Nouet, G. [LERMAT, ISMRA, Caen (France); Mestres, N. [Institut de Ciencia de Materials de Barcelona, (CSIC), E-08193, Bellaterra (Spain)

    1999-11-01

    Boron nitride films deposited on unheated c-Si substrates by ion beam assisted deposition (IBAD) and triode sputtering (TS) techniques are studied. The composition, microstructure and crystallinity of the films obtained by the two techniques are compared The methods of characterization used in this study are: X-ray photo-electron, infrared, and Raman spectroscopies. High-resolution cross sectional TEM is used to confirm the optical results. In the case of films prepared by IBAD, the ion energy was 350-500 eV. The films were prepared from different gas mixtures of nitrogen and argon, boron was supplied by evaporation of elemental boron. TS films were prepared with 100% of nitrogen, the boron was supplied by sputtering a pure boron target. This study shows that, in comparison with TS samples, IBAD samples have higher chemical and physical stability. The particle-size dependence of frequencies and damping of optical phonons is studied for all samples from the analysis of Raman scattering and infrared spectra. A very important difference between the particle-sizes of IBAD and TS samples is observed. A progressive chemical etching by nitric acid at 80 C combined with infrared characterization was successfully performed on IBAD samples deposited at low ion flux and announces a mixture of sp{sup 2} and sp{sup 3} phases with high content of sp{sup 3} structure. All results are in full agreements with TEM results. (orig.)

  18. Synthesis and magnetic properties of barium-calcium hexaferrite particles prepared by sol-gel and microemulsion techniques

    Energy Technology Data Exchange (ETDEWEB)

    Jotania, R.B. [Department of Physics, Gujarat University, Ahmedabad 380 009, Gujarat (India)], E-mail: rbjotania@gmail.com; Khomane, R.B. [Chemical Engineering Division, National Chemical Laboratory, Pune 411008, Maharastra (India); Chauhan, C.C. [Department of Physics, Gujarat University, Ahmedabad 380 009, Gujarat (India); Menon, S.K. [Department of Chemistry, Gujarat University, Ahmedabad 380 009, Gujarat (India); Kulkarni, B.D. [Chemical Engineering Division, National Chemical Laboratory, Pune 411008, Maharastra (India)

    2008-03-15

    The preparation of W-type hexaferrite particles with the composition BaCa{sub 2}Fe{sub 16}O{sub 27} by microemulsion and a stearic acid sol-gel method with and without surfactant has been investigated at various sintering temperatures. The structural and magnetic characteristics have been studied by X-ray diffraction (XRD), a vibrating sample magnetometer (VSM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetric (DSC) and Fourier transform infrared (FTIR) techniques. The effect of sintering temperature on the properties of BaCa{sub 2}Fe{sub 16}O{sub 27} hexaferrites has been studied. The value of saturation magnetization (M{sub s}) depends on types of surfactant used. The sample prepared in the presence of polyoxyethylene (20) sorbitan monooleat (Tween 80) shows low saturation magnetization (M{sub s}=15.10 emu/g), whereas the other sample prepared in the presence of a surfactant cetyltrimethylammonium bromide (CTAB) exhibits high saturation magnetization (M{sub s}=24.60 emu/g) compared to the normal sample.

  19. Aqueous Heck cross-coupling preparation of acrylate-modified nucleotides and nucleoside triphosphates for polymerase synthesis of acrylate-labeled DNA.

    Science.gov (United States)

    Dadová, Jitka; Vidláková, Pavlína; Pohl, Radek; Havran, Luděk; Fojta, Miroslav; Hocek, Michal

    2013-10-04

    Aqueous-phase Heck coupling methodology was developed for direct attachment of butyl acrylate to 5-iodoracil, 5-iodocytosine, 7-iodo-7-deazaadenine, and 7-iodo-7-deazaguanine 2'-deoxyribonucleoside 5'-O-monophosphates (dNMPs) and 5'-O-triphosphates (dNTPs) and compared with the classical approach of phosphorylation of the corresponding modified nucleosides. The 7-substituted 7-deazapurine nucleotides (dA(BA)MP, dA(BA)TP, dG(BA)MP, and dG(BA)TP) were prepared by the direct Heck coupling of nucleotides in good yields (35-55%), whereas the pyrimidine nucleotides reacted poorly and the corresponding BA-modified dNTPs were prepared by triphosphorylation of the modified nucleosides. The acrylate-modified dN(BA)TPs (N = A, C, and U) were good substrates for DNA polymerases and were used for enzymatic synthesis of acrylate-modified DNA by primer extension, whereas dG(BA)TP was an inhibitor of polymerases. The butyl acrylate group was found to be a useful redox label giving a strong reduction peak at -1.3 to -1.4 V in cyclic voltammetry.

  20. Recovery of silica from electronic waste for the synthesis of cubic MCM-48 and its application in preparing ordered mesoporous carbon molecular sieves using a green approach

    Science.gov (United States)

    Liou, Tzong-Horng

    2012-07-01

    The electronics industry is one of the world's fastest growing manufacturing industries. However, e-waste has become a serious pollution problem. This study reports the recovery of e-waste for preparing valuable MCM-48 and ordered mesoporous carbon for the first time. Specifically, this study adopts an alkali-extracted method to obtain sodium silicate precursors from electronic packaging resin ash. The influence of synthesis variables such as gelation pH, neutral/cationic surfactant ratio, hydrothermal treatment temperature, and calcination temperature on the mesophase of MCM-48 materials is investigated. Experimental results confirm that well-ordered cubic MCM-48 materials were synthesized in strongly acidic and strongly basic media. The resulting mesoporous silica had a high surface area of 1,317 m2/g, mean pore size of about 3.0 nm, and a high purity of 99.87 wt%. Ordered mesoporous carbon with high surface area (1,715 m2/g) and uniform pore size of CMK-1 type was successfully prepared by impregnating MCM-48 template using the resin waste. The carbon structure was sensitive to the sulfuric acid concentration and carbonization temperature. Converting e-waste into MCM-48 materials not only eliminates the disposal problem of e-waste, but also transforms industrial waste into a useful nanomaterial.

  1. The Synthesis of Anatase Nanoparticles and the Preparation of Photocatalytically Active Coatings Based on Wet Chemical Methods for Self-Cleaning Applications

    Directory of Open Access Journals (Sweden)

    Dejan Verhovšek

    2012-01-01

    Full Text Available We report on an improved sol-gel method for the production of highly photocatalytic titanium dioxide (TiO2 anatase nanoparticles which can provide appropriate control over the final characteristics of the nanoparticles, such as particle size, crystallinity, crystal structure, morphology, and also the degree of agglomeration. The synthesized anatase nanoparticles were characterized using various techniques, such as X-ray powder diffraction (XRD, scanning electron microscopy (SEM, and transmission electron microscopy (TEM, and were tested in coatings for self-cleaning glass and ceramic surfaces. The coatings were prepared using a soft chemistry route and are completely transparent to visible light and exhibit a high photocatalytic effect, which was determined by contact-angle measurements. Finally, it is worth mentioning that both the sol-gel synthesis method and the coating-preparation method are based on a wet chemical process, thus presenting no risk of handling the TiO2 anatase nanoparticles in their potentially hazardous powder form at any stage of our development. Low-price, easy-to-handle, and nontoxic materials were used. Therefore, our work represents an important contribution to the development of TiO2 anatase nanoparticle coatings that provide a high photocatalytic effect and can thus be used for numerous applications.

  2. Synthesis and Characterization of Nanoparticles and Nanocomposite of ZnO and MgO by Sonochemical Method and their Application for Zinc Polycarboxylate Dental Cement Preparation

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Karimi

    2011-01-01

    Full Text Available This paper discusses the synthesis of nanoparticles of ZnO and MgO and ZnO/MgO nanocomposite by the sonochemical method. At first, nanoparticles were synthesized by the reaction of Zn(CHCOO32 and Mg(CHCOO32 with tetramethylammonium hydroxide (TMAH in the presence of polyvinyl pyrrolidone (PVP and constant frequency ultrasonic waves (sonochemical method. Then, ZnO/MgO nanocomposite was prepared through reaction of magnesium acetate with TMAH in the presence of ZnO nanoparticles and PVP as structure director using ultrasonic assisted method. After filtration, the synthesized solution was obtained containing magnesium hydroxide in the presence of ZnO nanoparticles. It was calcinated at the temperature of 550 ºC, so that ZnO/MgO nanocomposite could be produced. The effects of different parameters on particle size and morphology of final ZnO and MgO powders and ZnO/MgO nanocomposite were optimized by ‘‘one at a time’’ method. Under optimum conditions, spongy shaped, uniformed and homogeneous nanostructured zinc oxide and magnesium oxide powders were obtained with particle sizes of 25–50 and 30-60 nm, respectively. ZnO/MgO nanocomposite was also obtained with more spongy morphology and particle size about 65 nm. Both synthesized ZnO and MgO nanoparticles and ZnO/MgO nanocomposite were successfully applied to the preparation of zinc polycarboxylate dental cement.

  3. Preparation of highly photocatalytic active CdS/TiO{sub 2} nanocomposites by combining chemical bath deposition and microwave-assisted hydrothermal synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Li, Li, E-mail: qqhrll@163.com [College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China); Key Laboratory of Composite Modified Material of Colleges in Heilongjiang Province, Qiqihar 161006 (China); Wang, Lili [College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China); Hu, Tianyu [College of Environment and Resources, Jilin University, Changchun 130024 (China); Zhang, Wenzhi; Zhang, Xiuli; Chen, Xi [College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China)

    2014-10-15

    CdS/TiO{sub 2} nanocomposites were prepared from Cd and Ti (1:1 M ratio) using cetyltrimethylammonium bromide by a two-step chemical bath deposition (CBD) and microwave-assisted hydrothermal synthesis (MAHS) method. A series of nanocomposites with different morphologies and activities were prepared by varying the reaction time in the MAHS (2, 4, and 6 h). The crystal structure, morphology, and surface physicochemical properties of the nanocomposites were characterized by X-ray diffraction, UV–visible diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and N{sub 2} adsorption–desorption measurements. The results show that the CdS/TiO{sub 2} nanocomposites were composed of anatase TiO{sub 2} and hexagonal CdS phases with strong absorption in the visible region. The surface morphologies changed slightly with increasing microwave irradiation time, while the Brunauer–Emmett–Teller surface area increased remarkably. The photocatalytic degradation of methyl orange (MO) was investigated under UV light and simulated sunlight irradiation. The photocatalytic activity of the CdS/TiO{sub 2} (6 h) composites prepared by the MAHS method was higher than those of CdS, P25, and other CdS/TiO{sub 2} nanocomposites. The CdS/TiO{sub 2} (6 h) nanocomposites significantly affected the UV and microwave-assisted photocatalytic degradation of different dyes. To elucidate the photocatalytic reaction mechanism for the CdS/TiO{sub 2} nanocomposites, controlled experiments were performed by adding different radical scavengers. - Graphical abstract: CdS/TiO{sub 2} nanocomposites were prepared using CTAB by CBD combined with MAHS method. In addition, with increasing microwave irradiation time, the morphology of CdS/TiO{sub 2} changed from popcorn-like to wedge-like structure. - Highlights: • The CdS/TiO{sub 2} was prepared by CBD combined with MAHS two-step method under CTAB. • The morphologies of as-samples were different with the time of

  4. Novel Biodegradable Polyesters. Synthesis and Application as Drug Carriers for the Preparation of Raloxifene HCl Loaded Nanoparticles

    Directory of Open Access Journals (Sweden)

    Evangelos Karavas

    2009-07-01

    Full Text Available Raloxifene HCl is a drug with poor bioavailability and poor water solubility. Furthermore nο pharmaceutically acceptable organic solvent has been reported before to dilute the drug. It was observed that Raloxifene HCl can be diluted in a solvent mixture of acetone/water or ethanol/water. The aim of this study was to use biodegradable polymers in order to prepare Raloxifene HCl nanoparticles. For this purpose a series of novel biodegradable poly(ethylene succinate-co-propylene adipate P(ESu-co-PAd polyesters were synthesized following the polycondensation method and further, poly(ethylene succinate (PESu and poly(propylene adipate (PPAd were used. The prepared polyesters were characterized by intrinsic viscosity measurements, end group analysis, enzymatic hydrolysis, Nuclear Magnetic Resonance Spectroscopy (1Η-NMR and 13C-NMR and Wide-angle X-ray Diffractometry (WAXD. The drug nanoparticles have been prepared by a variation of the co-precipitation method and were studied by Wide-angle X-ray Diffractometry (WAXD, FTIR spectrometry, light scattering size distribution, Scanning Electron Microscopy (SEM and release behavior measurements. The interactions between the polymers and the drug seem to be limited, so the drug occurs in crystalline form in all nanoparticles. The size of the nanoparticles seems to be in the range of 150-350 nm, depending on the polymer that was used. The drug release depends on the melting point and degree of crystallinity of the polyesters used. An initial high release rate was recorded followed by very slow rates of controlled release.

  5. Controlled silver delivery by silver-cellulose nanocomposites prepared by a one-pot green synthesis assisted by microwaves

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Ana Rosa; Unali, Gianfranco, E-mail: ana.rosa.silva@ua.pt [Structured Materials Expertise Group, Unilever Discover Port Sunlight, Quarry Road East, Bebington CH63 3JW (United Kingdom)

    2011-08-05

    Controlled silver release from cellulosic nanocomposites was achieved by synthesizing silver nanoparticles, under microwave heating for 1-15 min, in a one-pot, versatile and sustainable process in which microcrystalline cellulose simultaneously functions as reducing, stabilizing and supporting agent in water; chitin, starch and other cellulose derivatives could also be used as reducing, stabilizing and supporting agents for silver nanoparticles and the method was also found to be extensible to the preparation of noble metal (Au, Pt) and metal oxide nanoparticle (ZnO, Cu, CuO and Cu{sub 2}O) nanocomposites.

  6. Controlled silver delivery by silver-cellulose nanocomposites prepared by a one-pot green synthesis assisted by microwaves

    Science.gov (United States)

    Rosa Silva, Ana; Unali, Gianfranco

    2011-08-01

    Controlled silver release from cellulosic nanocomposites was achieved by synthesizing silver nanoparticles, under microwave heating for 1-15 min, in a one-pot, versatile and sustainable process in which microcrystalline cellulose simultaneously functions as reducing, stabilizing and supporting agent in water; chitin, starch and other cellulose derivatives could also be used as reducing, stabilizing and supporting agents for silver nanoparticles and the method was also found to be extensible to the preparation of noble metal (Au, Pt) and metal oxide nanoparticle (ZnO, Cu, CuO and Cu2O) nanocomposites.

  7. The Comparison of Hydrochloric Acid and Phosphoric Acid Treatments in the Preparation of Montmorillonite Catalysts for RNA Synthesis

    Science.gov (United States)

    Aldersley, Michael Frank; Joshi, Prakash C.; Huang, Yixing

    2017-09-01

    The treatment of clay minerals with a preliminary acid wash and titration to pH 7 has proven to generate catalysts for the most interesting of oligomerization reactions in which activated RNA-nucleotides generate oligomers up to 40-mers. Significantly, not all clay minerals become catalytic following this treatment and none are catalytic in the absence of such treatment. The washing procedure has been modified and explored further using phosphoric acid and the outcomes are compared to those obtained when clay samples are prepared following a hydrochloric acid wash.

  8. The Comparison of Hydrochloric Acid and Phosphoric Acid Treatments in the Preparation of Montmorillonite Catalysts for RNA Synthesis.

    Science.gov (United States)

    Aldersley, Michael Frank; Joshi, Prakash C; Huang, Yixing

    2017-09-01

    The treatment of clay minerals with a preliminary acid wash and titration to pH 7 has proven to generate catalysts for the most interesting of oligomerization reactions in which activated RNA-nucleotides generate oligomers up to 40-mers. Significantly, not all clay minerals become catalytic following this treatment and none are catalytic in the absence of such treatment. The washing procedure has been modified and explored further using phosphoric acid and the outcomes are compared to those obtained when clay samples are prepared following a hydrochloric acid wash.

  9. HYDROCARBON FORMATION ON POLYMER-SUPPORTED COBALT

    Energy Technology Data Exchange (ETDEWEB)

    Benner, Linda S.; Perkins, Patrick; Vollhardt, K.Peter C.

    1980-10-01

    In this report we detail the synthesis catalytic chemistry of polystyrene supported {eta}{sup 5} ~cyclopentadienyl- dicarbonyl cobalt, CpCo(CO){sub 2}. This material is active in the hydrogenation of CO to saturated linear hydrocarbons and appears to retain its "homogeneous", mononuclear character during the course of its catalysis, During ·the course of our work 18% and 20% crosslinked analogs of polystyrene supported CpCo(CO){sub 2} were shown to exhibit limited catalytic activity and no CO activation.

  10. Water Absorption Behavior of Polystyrene Particles Prepared by Emulsion Polymerization with Nonionic Emulsifiers and Innovative Easy Synthesis of Hollow Particles.

    Science.gov (United States)

    Okubo, Masayoshi; Kobayashi, Hiroshi; Huang, Chujuan; Miyanaga, Eri; Suzuki, Toyoko

    2017-04-11

    Submicrometer-sized raspberry-like polystyrene (PS) particles, which were prepared by emulsion polymerization with polyoxyethylene nonylphenyl ether nonionic emulsifier (Emulgen 910, HLB 12.2) and potassium persulfate initiator, contained 8.5 vol % (relative to the particle) of water and 5.5 wt % (relative to PS) of Emulgen 910 in the inside. The water absorption decreased the glass transition temperature of the PS particles dispersed in an aqueous medium. The wt % (relative to PS) of the incorporated Emulgen 910 increased with increasing initial Emulgen 910 concentration in the emulsion polymerization, but the wt % (relative to the total Emulgen 910 used) of the incorporated Emulgen 910 was constant at approximately 50% independent of the initial concentration. The vol % (relative to particle) of water increased to 46% by heat treatment at 90 °C for 24 h, which was based on further water absorption, and resulted in spherical hollow particles, where the amount of the incorporated Emulgen 910 remarkably decreased in a short treatment and then remained almost constant during the heat treatment. After another 24 h treatment, the percentage of nonhollow particles increased gradually, which was based on the escape of the water domain together with Emulgen 910 from the inside of the particles. On the other hand, spherical PS particles prepared by emulsifier-free emulsion polymerization did not contain water in the inside and were not changed to hollow ones by a similar heat treatment. From these results, an innovative easy method to synthesize hydrophobic hollow PS particles is proposed.

  11. Synthesis of SiO2-Coated Core-Shell ZnO Composites for Preparing High-Voltage Varistors

    Science.gov (United States)

    Qu, Xiao; Yao, Da-Chuan; Liu, Jin-Ran; Wang, Mao-Hua; Zhang, Han-Ping

    2017-09-01

    Monodispersed ZnO composite microspheres were successfully prepared by a facile ultrasound irradiation method. Then, the uniform core-shell structured composites were synthesized through the hydrolysis of tetraethyl orthosilicate on the surface of the ZnO composite microspheres. Microstructural studies of the as-obtained powders were carried out using the techniques of the x-ray powder diffraction, field emission scanning electron microscopy and transmission electron microscopy with energy dispersive x-ray spectroscopy. The results show that the pink ZnO composite powders as the core were spherical structures with the size of approximately 100 nm, and the SiO2 shell was fully coated on the surface of the core. On the basis of these results, the effect of SiO2 content on the thickness of the synthesized composites and microstructure, as well as the electrical properties of the ZnO varistors sintered in air at 1150°C for 2 h, were fully studied. In particular, the ZnO varistor prepared with the appropriate amount of the SiO2 coating (˜40 nm) leads to a superior electrical performance with the high breakdown voltage of 418 V mm-1 and an excellent nonlinear coefficient of 70.7, compared with the varistors obtained without the SiO2 coating. The high performance is attributed to the smaller and more homogeneous ZnO grains obtained via the SiO2 coating.

  12. Photocatalytic degradation of methyl orange over nitrogen-fluorine codoped TiO2 nanobelts prepared by solvothermal synthesis.

    Science.gov (United States)

    He, Zuoli; Que, Wenxiu; Chen, Jing; Yin, Xingtian; He, Yucheng; Ren, Jiangbo

    2012-12-01

    Anatase type nitrogen-fluorine (N-F) codoped TiO(2) nanobelts were prepared by a solvothermal method in which amorphous titania microspheres were used as the precursors. The as-prepared TiO(2) nanobelts are composed of thin narrow nanobelts and it is noted that there are large amount of wormhole-like mesopores on these narrow nanobelts. Photocatalytic activity of the N-F codoped TiO(2) nanobelts was measured by the reaction of photocatalytic degradation of methyl orange. Results indicate that the photocatalytic activity of the N-F codoped TiO(2) nanobelts is higher than that of P25, which is mainly ascribed to wormhole-like mesopores like prison, larger surface area, and enhanced absorption of light due to N-F codoping. Interestingly, it is also found that the photocatalytic activity can be further enhanced when tested in a new testing method because more photons can be captured by the nanobelts to stimulate the formation of the hole-electron pair.

  13. Synthesis of SiO2-Coated Core-Shell ZnO Composites for Preparing High-Voltage Varistors

    Science.gov (United States)

    Qu, Xiao; Yao, Da-Chuan; Liu, Jin-Ran; Wang, Mao-Hua; Zhang, Han-Ping

    2018-01-01

    Monodispersed ZnO composite microspheres were successfully prepared by a facile ultrasound irradiation method. Then, the uniform core-shell structured composites were synthesized through the hydrolysis of tetraethyl orthosilicate on the surface of the ZnO composite microspheres. Microstructural studies of the as-obtained powders were carried out using the techniques of the x-ray powder diffraction, field emission scanning electron microscopy and transmission electron microscopy with energy dispersive x-ray spectroscopy. The results show that the pink ZnO composite powders as the core were spherical structures with the size of approximately 100 nm, and the SiO2 shell was fully coated on the surface of the core. On the basis of these results, the effect of SiO2 content on the thickness of the synthesized composites and microstructure, as well as the electrical properties of the ZnO varistors sintered in air at 1150°C for 2 h, were fully studied. In particular, the ZnO varistor prepared with the appropriate amount of the SiO2 coating (˜40 nm) leads to a superior electrical performance with the high breakdown voltage of 418 V mm-1 and an excellent nonlinear coefficient of 70.7, compared with the varistors obtained without the SiO2 coating. The high performance is attributed to the smaller and more homogeneous ZnO grains obtained via the SiO2 coating.

  14. HYDROCARBON PROSPECTING OVE DROCARBON ...

    African Journals Online (AJOL)

    eobe

    e trapping configurations of the faults mbedding shale were presumed to be the creation of multiple reservoir of hydrocarbon bearing formations one horizon to the other and. (Figure 2). The vertical f the major and subsidiary growth t the amount of throw of both major s are small and varied from line to line survey but ...

  15. A STUDY OF THE SYNTHESIS OF VERATRYL CYANIDE REQUIRED AS AN INTERMEDIATE FOR THE PREPARATION OF C-9154 ANTIBIOTIC DERIVATIVE FROM VANILIN

    Directory of Open Access Journals (Sweden)

    Ila Rosilawati

    2010-06-01

    Full Text Available The synthesis of veratryl cyanide [1-(3,4-dimethoxy phenyl acetonitril] required as an intermediate for the preparation of C-9154 antibiotic derivative was carried out. The starting material used was vanilin, while the reaction steps consisted of (1 methylation of vanilin, (2 reduction of veratraldehyde, (3 synthesis of veratryl bromide, and (4 treatment of this bromide with KCN. The analysis of the products was carried out using IR, 1H NMR and GC-MS spectrophotometers.             The methylation of vanilin was conducted using dimethylsulfate and NaOH at 100  oC for 2 hours to give 79.3% yield of veratraldehyde. The reduction of veratraldehyde with LiBH4 in ethanol - THF mixture (1:1 v/v at reflux for 4 hours afforded veratryl alcohol in 85.3% yield. This veratryl alcohol was treated with red phosphorous and Br2 in CCl4 at 60 oC for 2 hours to give 1-(2-bromo-4,5-dimethoxy-phenyl bromomethane in 67.4% yield, instead of the desired veratryl bromide [1-3,4-dimethoxy-phenyl bromomethane]. This benzyl bromide derivative was then treated with KCN in the presence of tween 80 as a phase catalyst transsfer in benzene-water solvent system at reflux for 2 hours to yield 1-(2-bromo-4,5-dimethoxyphenyl acetonitril in 58.5%.   Keywords: Vanilin, veratryl cyanide, C-9154 antibiotic derivative

  16. Synthesis of a bimodal porous Cu with nanopores on the inner surface of Gasar pores: Influences of preparation conditions

    Science.gov (United States)

    Du, Ming; Zhang, Hua-wei; Li, Yan-xiang; Liu, Yuan; Chen, Xiang; He, Yun

    2016-01-01

    A bimodal porous Cu with regular Gasar micrometer or millimeter pores and random dealloying nanometer pores was fabricated by chemical corrosion of Cu-Zn alloy layers on the inner surface of Gasar Cu pores. In order to accomplish this object, a two-step corrosion method was conducted, including the selective corrosion of Zn element from Cu-Zn alloy layers by NaOH solution, and the removal of the surface oxide obtained in the first step to expose the bottom nanoporous Cu films by HCl solution. Influences of preparation conditions, such as HCl solution concentration and processing time, NaOH solution dealloying time, Gasar pore diameter, and the distance from Gasar pore openings on the microstructure of the resulting nanoporous Cu films were discussed.

  17. Synthesis of silver nanoparticles deposited on silica by γ-irradiation and preparation of PE/Ag nano compound masterbatches

    Science.gov (United States)

    Nguyen, Thi Kim Lan; Trinh Nguyen, Thuy Ai; Phu Dang, Van; Duy Nguyen, Ngoc; Le, Anh Quoc; Hien Nguyen, Quoc

    2013-12-01

    Silver nanoparticles (AgNPs) deposited on silica were synthesized by gamma Co-60 irradiation of Ag+ dispersion in silica/ethanol/water mixture (9/80/20:w/v/v). The reduction of Ag+ is occurred by hydrated electron (e-aq) and hydrogen atom (H•) generated during radiolysis of ethanol/water. The conversion doses (Ag+ → Ag0) were determined by UV-Vis spectroscopy. The synthesized AgNPs/silica were characterized by transmission electron microscopy (TEM) and x-ray diffraction (XRD), which showed the size of AgNPs to be in the range of 5-40 nm for Ag+ concentrations from 5 to 20 mM. Masterbatches of PE/AgNPs/silica compound with silver content from 250 to 1000 mg kg-1 were also prepared. These masterbatches can be suitably used for various applications such as antimicrobial food containers and packing films, etc.

  18. Structure and Optical Properties of Titania-PDMS Hybrid Nanocomposites Prepared by In Situ Non-Aqueous Synthesis

    Directory of Open Access Journals (Sweden)

    Antoine R. M. Dalod

    2017-12-01

    Full Text Available Organic-inorganic hybrid materials are attractive due to the combination of properties from the two distinct types of materials. In this work, transparent titania-polydimethylsiloxane hybrid materials with up to 15.5 vol. % TiO2 content were prepared by an in situ non-aqueous method using titanium (IV isopropoxide and hydroxy-terminated polydimethylsiloxane as precursors. Spectroscopy (Fourier transform infrared, Raman, Ultraviolet-visible, ellipsometry and small-angle X-ray scattering analysis allowed to describe in detail the structure and the optical properties of the nanocomposites. Titanium alkoxide was successfully used as a cross-linker and titania-like nanodomains with an average size of approximately 4 nm were shown to form during the process. The resulting hybrid nanocomposites exhibit high transparency and tunable refractive index from 1.42 up to 1.56, depending on the titania content.

  19. 40% Efficiency enhancement in solar cells using ZnO nanorods as shell prepared via novel hydrothermal synthesis

    Science.gov (United States)

    Ebadi, Mohammad; Zarghami, Zabihullah; Motevalli, Kourosh

    2017-03-01

    Herein, rod-like ZnO nanostructures were synthesized via a novel hydrothermal route using Zn(OAc)2, ethylenediamine and hydrazine as a new set of starting reagents. The as-synthesized products were characterized by techniques including XRD, EDS, SEM, XPS, Pl and FTIR. The prepared ZnO nanostructures were utilized as shell on TiO2 film in DSSCs. Effect of precursor type, morphology and thickness of ZnO shell (number of electrophoresis cycle) on solar cells efficiency were well studied. Our results showed that ethylenediamine has crucial effect on morphology of synthesized ZnO nanostructures and using ZnO nanostructures leads to an increase in DSSCs efficiency compared to bare TiO2 from 4.66 to 7.13% ( 40% improvement). Moreover, highest amount of solar cell efficiency (7.13%) was obtained by using ZnO nanorods with two cycle of electrophoresis for deposition.

  20. Synthesis and photoluminescent properties of yttrium vanadate phosphor prepared by the non-hydrolytic sol–gel process

    Energy Technology Data Exchange (ETDEWEB)

    Matos, Marcela G.; Faria, Emerson H. de; Rocha, Lucas A.; Calefi, Paulo S.; Ciuffi, Katia J. [Universidade de Franca, Av. Dr. Armando Salles Oliveira, 201 Franca, SP, CEP 14404-600 (Brazil); Nassar, Eduardo J., E-mail: ejnassar@unifran.br [Universidade de Franca, Av. Dr. Armando Salles Oliveira, 201 Franca, SP, CEP 14404-600 (Brazil); Sarmento, Victor Hugo Vitorino [Universidade Federal de Sergipe, Av. Ver. Olimpio Grande s/n Itabaiana, SE, CEP 49500-000 (Brazil)

    2014-03-15

    We used the non-hydrolytic sol–gel route to synthesize YVO{sub 4} crystalline phases doped with europium III ion. We heat-treated the samples at 600, 800, and 1000 °C and characterized the materials by thermal analysis, X-ray diffraction, small-angle X-ray scattering, and photoluminescence. Larger weight loss occurred until 500 °C, ascribed to removal of residual precursor molecules. X-ray diffraction patterns evidenced YVO{sub 4} phase formation at 600 °C. The crystallite size depended on the heat treatment temperature. SAXS showed that the nature of the system interfaces changed as a function of the thermal treatment. The excitation spectra of the samples displayed the charge transfer band. The photoluminescence data revealed the characteristic transition bands arising from the {sup 5}D{sub 0}→{sup 5}F{sub J} (J=0, 1, 2, 3, and 4) manifolds under maximum excitation at the charge transfer band and the {sup 5}L{sub 6} level of the Eu{sup 3+} ion. The {sup 5}D{sub 0}→{sup 7}F{sub 2} transition dominated the emission spectra, indicating that the Eu{sup 3+} ion occupies a site without inversion center. The lifetime and quantum efficiency values were about 0.70 ms and 50%, respectively, corroborating literature results. -- Highlights: • This study described the preparation of the yttrium vanadate by non-hydrolytic sol–gel. • The SAXS curves can be interpreted from the fractal theory for a two-phase model. • The goal of the work is the preparation of the phosphors at low temperature. • The lifetimes depend on wavelength of the excitation.

  1. Synthesis, structural characterisation and antibacterial activity of Ag{sup +}-doped fluorapatite nanomaterials prepared by neutralization method

    Energy Technology Data Exchange (ETDEWEB)

    Stanić, Vojislav, E-mail: voyo@vinca.rs [University of Belgrade, Vinča Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade (Serbia); Radosavljević-Mihajlović, Ana S. [University of Belgrade, Vinča Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade (Serbia); Živković-Radovanović, Vukosava [University of Belgrade, Faculty of Chemistry, P.O. Box 51, 11158 Belgrade (Serbia); Nastasijević, Branislav; Marinović-Cincović, Milena; Marković, Jelena P.; Budimir, Milica D. [University of Belgrade, Vinča Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade (Serbia)

    2015-05-15

    Graphical abstract: - Highlights: • The neutralization method has been used for synthesis of silver-doped fluorapatite powders. • Particles of silver-doped fluorapatite samples are of nano size and homogenous in composition. • The Ag{sup +}-doped fluorapatite samples showed antibacterial effect against Kllebsiela pneumoniae, Staphylococcus aureus and Micrococcus luteus. • AFM studies showed that silver-doped sample causes considerable morphological changes of tested bacterial cells. - Abstract: Silver doped fluorapatite nanopowders were synthesised by neutralization method, which consists of dissolving Ag{sub 2}O in solution of HF and H{sub 3}PO{sub 4} and addition to suspension of Ca(OH){sub 2}. The powder XRD, SEM and FTIR studies indicated the formation of a fluorapatite nanomaterials with average length of the particles is about 80 nm and a width of about 15 nm. The FTIR studies show that carbonate content in samples is very small and carbonte ions substitute both phosphate and hydroxyl groups in the crystal structure of samples, forming AB-type fluorapatite. Antibacterial studies have demonstrated that all Ag{sup +}-doped fluorapatite samples exhibit bactericidal effect against pathogens: Staphylococcus aureus, Micrococcus luteus and Kllebsiela pneumoniae. Antibacterial activity increased with the increase of Ag{sup +} in the samples. The atomic force microscopy studies revealed extensive damage to the bacterial cell envelops in the presence of Ag{sup +}-doped fluorapatite particles which may lead to their death. The synthesized Ag{sup +}-doped fluorapatite nanomaterials are promising as antibacterial biomaterials in orthopedics and dentistry.

  2. Synthesis Mechanism of Low-Voltage Praseodymium Oxide Doped Zinc Oxide Varistor Ceramics Prepared Through Modified Citrate Gel Coating

    Directory of Open Access Journals (Sweden)

    Wan Rafizah Wan Abdullah

    2012-04-01

    Full Text Available High demands on low-voltage electronics have increased the need for zinc oxide (ZnO varistors with fast response, highly non-linear current-voltage characteristics and energy absorption capabilities at low breakdown voltage. However, trade-off between breakdown voltage and grain size poses a critical bottle-neck in the production of low-voltage varistors. The present study highlights the synthesis mechanism for obtaining praseodymium oxide (Pr6O11 based ZnO varistor ceramics having breakdown voltages of 2.8 to 13.3 V/mm through employment of direct modified citrate gel coating technique. Precursor powder and its ceramics were examined by means of TG/DTG, FTIR, XRD and FESEM analyses. The electrical properties as a function of Pr6O11 addition were analyzed on the basis of I-V characteristic measurement. The breakdown voltage could be adjusted from 0.01 to 0.06 V per grain boundary by controlling the amount of Pr6O11 from 0.2 to 0.8 mol%, without alteration of the grain size. The non-linearity coefficient, α, varied from 3.0 to 3.5 and the barrier height ranged from 0.56 to 0.64 eV. Breakdown voltage and α lowering with increasing Pr6O11 content were associated to reduction in the barrier height caused by variation in O vacancies at grain boundary.

  3. Surfactant-controlled composition and crystal structure of manganese(II sulfide nanocrystals prepared by solvothermal synthesis

    Directory of Open Access Journals (Sweden)

    Elena Capetti

    2015-12-01

    Full Text Available We investigated how the outcome of the solvothermal synthesis of manganese(II sulfide (MnS nanocrystals (NCs is affected by the type and amount of long chain surfactant present in the reaction mixture. Prompted by a previous observation that a larger than stoichiometric amount of sulfur is required [Puglisi, A.; Mondini, S.; Cenedese, S.; Ferretti, A. M.; Santo, N.; Ponti A. Chem. Mater. 2010, 22, 2804–2813], we carried out a wide set of reactions using Mn(II carboxylates and Mn2(CO10 as precursors with varying amounts of sulfur and carboxylic acid. MnS NCs were obtained provided that the S/Mn ratio was larger than the L/Mn ratio, otherwise MnO NCs were produced. Since MnS can crystallize in three distinct phases (rock salt α-MnS, zincblende β-MnS, and wurtzite γ-MnS, we also investigated whether the surfactant affected the NC polymorphism. We found that MnS polymorphism can be controlled by appropriate selection of the surfactant. γ-MnS nanocrystals formed when a 1:2 mixture of long chain carboxylic acid and amine was used, irrespective of the presence of carboxylic acid as a free surfactant or ligand in the metal precursor. When we used a single surfactant (carboxylic acid, alcohol, thiol, amine, α-MnS nanocrystals were obtained. The peculiar role of the amine seems to be related to its basicity. The nanocrystals were characterized by TEM and electron diffraction; ATR-FTIR spectroscopy provided information about the surfactants adsorbed on the NCs.

  4. Apolipoprotein C-II and lipoprotein lipase show a temporal and geographic correlation with surfactant lipid synthesis in preparation for birth

    Directory of Open Access Journals (Sweden)

    Gérard-Hudon Marie-Christine

    2010-11-01

    Full Text Available Abstract Background Fatty acids are precursors in the synthesis of surfactant phospholipids. Recently, we showed expression of apolipoprotein C-II (apoC-II, the essential cofactor of lipoprotein lipase (LPL, in the fetal mouse lung and found the protein on the day of the surge of surfactant synthesis (gestation day 17.5 in secretory granule-like structures in the distal epithelium. In the present study, we will answer the following questions: Does apoC-II protein localization change according to the stage of lung development, thus according to the need in surfactant? Are LPL molecules translocated to the luminal surface of capillaries? Do the sites of apoC-II and LPL gene expression change according to the stage of lung development and to protein localization? Results The present study investigated whether the sites of apoC-II and LPL mRNA and protein accumulation are regulated in the mouse lung between gestation day 15 and postnatal day 10. The major sites of apoC-II and LPL gene expression changed over time and were found mainly in the distal epithelium at the end of gestation but not after birth. Accumulation of apoC-II in secretory granule-like structures was not systematically observed, but was found in the distal epithelium only at the end of gestation and soon after birth, mainly in epithelia with no or small lumina. A noticeable increase in surfactant lipid content was measured before the end of gestation day 18, which correlates temporally with the presence of apoC-II in secretory granules in distal epithelium with no or small lumina but not with large lumina. LPL was detected in capillaries at all the developmental times studied. Conclusions This study demonstrates that apoC-II and LPL mRNAs correlate temporally and geographically with surfactant lipid synthesis in preparation for birth and suggests that fatty acid recruitment from the circulation by apoC-II-activated LPL is regionally modulated by apoC-II secretion. We propose a model

  5. Polynuclear Aromatic Hydrocarbons with Curved Surfaces: Buckyballs

    Energy Technology Data Exchange (ETDEWEB)

    Sygula, Andrzej [Mississippi State Univ., Mississippi State, MS (United States)

    2016-08-15

    The discovery of a new allotropic form of elemental carbon – the fullerenes – and subsequently other novel forms of elemental carbon with pyramidalized surfaces, most notably single-walled and multi-walled carbon nanotubes, introduced a novel structural motif to the polycyclic aromatic hydrocarbons (PAHs) with nonplanar surfaces. Our research program supported by BES DOE grant DE-FG02-04ER15514 has dealt with the synthesis, structural studies, and chemistry of the novel curved-surface PAHs with carbon frameworks structurally related to fullerenes. They are referred to as “buckybowls”. We prepared several new buckybowls and, even more importantly, developed the efficient, gram-scale synthetic methodologies for the preparation of small buckybowls, most notably corannulene (C20H10) and its derivatives. In addition, the employment of the corannulene-based synthons previously developed in our laboratory led to a number of highly nonplanar molecular architectures with two or more corannulene subunits with a potential for the applications as novel materials in separation sciences, nanoelectronics, photovoltaics and catalysis. In collaboration with Professor Angelici (Iowa State) we prepared and characterized several transition metal complexes of corannulene, providing the first structural characterization of η6 metal complexes of buckybowls by a single crystal X-ray diffraction. In addition to the definitive structural characterization of the complexes we demonstrated that the (η6-C6Me6)Ru2+ unit in some relatively stable complexes activate the corannulene ligand to react with proper nucleophiles suggesting that such complexex may be used in catalysis. (Section C). We have explored the efficiency of the dispersion-based interactions of curved-surface conjugated carbon networks by high-level computational models. We showed that the curvature of such networks does not reduce the van der Waals attractions as compared to the planar systems of similar size. We than

  6. Microbial degradation of petroleum hydrocarbons.

    Science.gov (United States)

    Varjani, Sunita J

    2017-01-01

    Petroleum hydrocarbon pollutants are recalcitrant compounds and are classified as priority pollutants. Cleaning up of these pollutants from environment is a real world problem. Bioremediation has become a major method employed in restoration of petroleum hydrocarbon polluted environments that makes use of natural microbial biodegradation activity. Petroleum hydrocarbons utilizing microorganisms are ubiquitously distributed in environment. They naturally biodegrade pollutants and thereby remove them from the environment. Removal of petroleum hydrocarbon pollutants from environment by applying oleophilic microorganisms (individual isolate/consortium of microorganisms) is ecofriendly and economic. Microbial biodegradation of petroleum hydrocarbon pollutants employs the enzyme catalytic activities of microorganisms to enhance the rate of pollutants degradation. This article provides an overview about bioremediation for petroleum hydrocarbon pollutants. It also includes explanation about hydrocarbon metabolism in microorganisms with a special focus on new insights obtained during past couple of years. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Preparation and characterization of Mg-modified zirconias as catalysts for the direct synthesis of dimethyl carbonate (DMC

    Directory of Open Access Journals (Sweden)

    Andrés Orrego Romero

    2011-01-01

    Full Text Available Se preparó circonia por el método sol-gel usando H2SO4, HNO3 o HCl como catalizadores de hidrólisis. Los materiales resultantes se caracterizaron por DRX, BET, FTIR, desorción de CO2 con temperatura programada (TPDCO 2 y desorción de amoníaco con temperatura programada (TPD-NH3. Los espectros FTIR de las muestras preparadas con H2SO4 muestran bandas típicas de sulfatos, lo cual se confirmó mediante TGA. Adicionalmente, en algunos materiales seleccionados se incorporaron diferentes proporciones de Mg mediante co-gelación. La carga de magnesio de los materiales modificados se determinó por análisis elemental. Los materiales se ensayaron como catalizadores en la síntesis directa de carbonato de dimetilo (DMC a partir de metanol y CO2. La incorporación de Mg incrementó la capacidad de adsorción de CO2 entre 100 y 200 ºC. No obstante, las conversiones de metanol obtenidas con estas muestras fueron menores a las de las muestras de circonia sin modificar.

  8. Synthesis and electromagnetic absorption properties of micro-nano nickel powders prepared with liquid phase reduction method

    Directory of Open Access Journals (Sweden)

    Ying Yu

    2016-09-01

    Full Text Available Monodisperse micro-nano nickel powders have been prepared by chemical reduction of aqueous solution NiSO4, NaOH and NaH2PO2, and the influence of pH value and initial concentration of NiSO4 on the size, structure, morphology and microwave absorption properties of nickel powders were investigated. The crystal structure of nickel powders was characterized by X-ray diffraction (XRD. And the morphology of the as-synthesized products was characterized by scanning electron microscopy (SEM and transmission electron microscopy (TEM. The microwave absorption properties of the composite materials were characterized by network analyzer. The result indicates that the growth of nickel powders produced by NiSO4 and NaH2PO2 at alkaline condition deeply relies on pH value and initial concentration of NiSO4 in reaction system. Different sizes of nickel powders with the diameter of 1.5μm and 180nm were produced at the pH value of 10 and initial concentration of NiSO4 at 0.5mol/L. The network analyzer showed definite microwave absorption properties of nickel powders with different sizes in the range of 0.5–18.0GHz.

  9. Preparation of LiMn2O4 Graphene Hybrid Nanostructure by Combustion Synthesis and Their Electrochemical Properties

    Directory of Open Access Journals (Sweden)

    Dinesh Rangappa

    2014-10-01

    Full Text Available The LiMn2O4 graphene hybrid cathode material has been synthesized by spray drying combustion process. The spinel structure cubic phase LiMn2O4 graphene hybrid material was prepared by spray drying process at 120 ℃ and subsequent heat treatment at 700 ℃ for 1 hour. The result indicates that the spinel shaped LiMn2O4 particles wrapped with graphene sheets were formed with particle size in the range of 60-70 nm. The charge-discharge measurement indicates that the LiMn2O4 graphene hybrid material shows an improved discharge capacity of 139 mAh/g at 0.1C rate. The pristine LiMn2O4 nano crystals present only about 132 mAh/g discharge capacity. The LiMn2O4 graphene hybrid samples show good cyclic performance with only 13% of capacity fading in 30 cycles when compared to the pristine LiMn2O4 that shows 22% of capacity fading in 30 cycles. The capacity retention of the LiMn2O4 graphene hybrid samples is about 10% higher than the pristine cycle after 30 cycles.

  10. Amino acid mediated synthesis of silver nanoparticles and preparation of antimicrobial agar/silver nanoparticles composite films.

    Science.gov (United States)

    Shankar, Shiv; Rhim, Jong-Whan

    2015-10-05

    Silver nanoparticles (AgNPs) were synthesized using amino acids (tyrosine and tryptophan) as reducing and capping agents, and they were incorporated into the agar to prepare antimicrobial composite films. The AgNPs solutions exhibited characteristic absorption peak at 420 nm that showed a red shift to ∼434 nm after forming composite with agar. XRD data demonstrated the crystalline structure of AgNPs with dominant (111) facet. Apparent surface color and transmittance of agar films were greatly influenced by the AgNPs. The incorporation of AgNPs into agar did not exhibit any change in chemical structure, thermal stability, moisture content, and water vapor permeability. The water contact angle, tensile strength, and modulus decreased slightly, but elongation at break increased after AgNPs incorporation. The agar/AgNPs nanocomposite films possessed strong antibacterial activity against Listeria monocytogenes and Escherichia coli. The agar/AgNPs film could be applied to the active food packaging by controlling the food-borne pathogens. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Preparation of antibacterial coating based on in situ synthesis of ZnO/SiO{sub 2} hybrid nanocomposite on cotton fabric

    Energy Technology Data Exchange (ETDEWEB)

    Barani, Hossein, E-mail: barani@birjand.ac.ir

    2014-11-30

    Graphical abstract: - Highlights: • In situ approach was used to synthesize ZnO/SiO{sub 2} nanocomposites. • Spherical structure and stabilized ZnO/SiO{sub 2} hybrid nanocomposites were synthesized. • The synthesized ZnO particles have a hexagonal wurtzite crystal structure. • The ZnO nanoparticles enhance the moisture content of cotton fabric. • ZnO/SiO{sub 2} loaded cotton fabrics presented a good antibacterial property. - Abstract: In this study, the antibacterial cotton fabric was prepared using zinc oxide/silicon dioxide (ZnO/SiO{sub 2}) nanocomposite. The ZnO nanoparticles were synthesized with an in situ approach using two different methods on the cotton fabric. One of the methods was to synthesize ZnO nanoparticles into the prepared sol solution, and then coating on the cotton fabric. The other method was to synthesize ZnO nanoparticles on the silicon dioxide-coated cotton fabric. The morphological, structural, thermal, and antibacterial properties of ZnO/SiO{sub 2} nanocomposite-coated cotton fabric was studied using scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffractometer, thermo gravimetric analysis, and Attenuated Total Reflection-Fourier Transform Infrared spectrometer. Synthesis of ZnO nanoparticles on the silicon dioxide coated cotton fabric sample resulted in agglomerated nanoparticles on the surface of cotton fiber, while the spherical nanoparticles structure was formed by synthesizing them into the sol solution of silicon dioxide. The EDS results indicated presence of ZnO/SiO{sub 2} nanocomposite on the surface of coated cotton fabric, and presented an inhibition zone against Staphylococcus aureus and Escherichia coli.

  12. Synthesis and Characterization of Low Loss Dielectric Ceramics Prepared from Composite of Titanate Nanosheets with Barium Ions

    Directory of Open Access Journals (Sweden)

    Aleksandra Wypych-Puszkarz

    2017-01-01

    Full Text Available We report a strategy for preparing barium titanate precursor, being the composite of titanate nanosheets (TN with barium ions (Ba-TN, which subjected to step sintering allows obtaining TiO2 rich barium titanate ceramics of stoichiometry BaTi4O9 or Ba2Ti9O20. These compounds are important in modern electronics due to their required dielectric properties and grains’ size that can be preserved in nanometric range. The morphology studies, structural characterization, and dielectric investigations were performed simultaneously in each step of Ba-TN calcinations in order to properly characterize type of obtained ceramic, its grains’ morphology, and dielectric properties. The Ba-TN precursor can be sintered at given temperatures, so that its dielectric permittivity can be tuned between 25 and 42 with controlled temperature coefficients that change from negative 32 ppm/°C for Ba-TN sintered at 900°C up to positive 37 ppm/°C after calcination at 1300°C. XRD analysis and Raman investigations performed for the Ba-TN in the temperature range of 900÷1250°C showed that below 1100°C we obtained as a main phase BaTi4O9, whereas the higher calcinations temperature transformed Ba-TN into Ba2Ti9O20. Taking into account trend of device miniaturization and nanoscopic size requirements, temperatures of 900°C and 1100°C seem to be an optimal condition for Ba-TN precursor calcinations that guarantee the satisfactory value of dielectric permittivity (ε=26 and 32 and ceramic grains with a mean size of ~180 nm and ~550 nm, respectively.

  13. (Quasi-)racemic X-ray structures of glycosylated and non-glycosylated forms of the chemokine Ser-CCL1 prepared by total chemical synthesis.

    Science.gov (United States)

    Okamoto, Ryo; Mandal, Kalyaneswar; Sawaya, Michael R; Kajihara, Yasuhiro; Yeates, Todd O; Kent, Stephen B H

    2014-05-12

    Our goal was to obtain the X-ray crystal structure of the glycosylated chemokine Ser-CCL1. Glycoproteins can be hard to crystallize because of the heterogeneity of the oligosaccharide (glycan) moiety. We used glycosylated Ser-CCL1 that had been prepared by total chemical synthesis as a homogeneous compound containing an N-linked asialo biantennary nonasaccharide glycan moiety of defined covalent structure. Facile crystal formation occurred from a quasi-racemic mixture consisting of glycosylated L-protein and non-glycosylated-D-protein, while no crystals were obtained from the glycosylated L-protein alone. The structure was solved at a resolution of 2.6-2.1 Å. However, the glycan moiety was disordered: only the N-linked GlcNAc sugar was well-defined in the electron density map. A racemic mixture of the protein enantiomers L-Ser-CCL1 and D-Ser-CCL1 was also crystallized, and the structure of the true racemate was solved at a resolution of 2.7-2.15 Å. Superimposition of the structures of the protein moieties of L-Ser-CCL1 and glycosylated-L-Ser-CCL1 revealed there was no significant alteration of the protein structure by N-glycosylation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Effect of pressure on the composition and superconducting T{sub c} value of NbN prepared by combustion synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Buscaglia, V. [Consiglio Nazionale delle Ricerche, Genoa (Italy). Ist. di Chimica Fisica Applicata dei Materiali; Caracciolo, F.; Ferretti, M.; Minguzzi, M. [Dipt. di Chimica e Chimica Industriale, Genoa (Italy); Musenich, R. [Istituto Nazionale di Fisica Nucleare, Genoa (Italy)

    1998-02-20

    The synthesis of niobium nitride by combustion of packed niobium powder under nitrogen atmosphere was studied in the pressure range 3.5-700 bar without solid-phase dilution. Surface melting of niobium was only detected at 30 bar. The reaction products consist of {delta}-NbN above 100 bar and of {gamma}-Nb{sub 4}N{sub 3}+{delta}-NbN at lower pressures. The lattice parameter of {delta}-NbN vs. the applied pressure presents a maximum corresponding to the transition from a predominantly defective nitrogen sublattice (N/Nb<1) to a predominantly defective niobium sublattice (N/Nb>1). Bulk metal-nitride components were obtained using a `chemical oven` configuration and combining the high pressure with the high combustion temperatures of the niobium powder. Thick nitride films of {approx}50 {mu}m with a critical superconducting temperature up to 17.2 K were prepared. The films consist of a {delta}-NbN external layer, of a {gamma}-Nb{sub 4}N{sub 3} intermediate layer and of a {beta}-Nb{sub 2}N inner layer. (orig.) 25 refs.

  15. One-pot synthesis of CdS nanoparticles exhibiting quantum size effect prepared within a sol-gel derived ureasilicate matrix

    Science.gov (United States)

    Gonçalves, Luis F. F. F.; Kanodarwala, Fehmida K.; Stride, John A.; Silva, Carlos J. R.; Gomes, Maria J. M.

    2013-12-01

    This paper describes a novel single-pot synthesis process based on sol-gel for the production of a highly transparent hybrid matrix containing CdS nanoparticles (NPs). The reaction between cadmium and sulphide ions in the presence of 3-mercaptopropyltrimethoxysilane (MPTMS) that originates the formation of quantum confined CdS NPs occurs simultaneously with the condensation and polymerization of the gel precursors that evolves to a macromolecular hybrid organic-inorganic network. The obtained xerogel matrix is based on the reaction of organically modified alkoxysilane (3-isocyanatepropyltriethoxysilane) and a di-amine functionalized oligopolyoxyethylene (Jeffamine ED-600). The final material is characterized as highly transparent, homogeneous and flexible xerogel incorporating stabilized and high crystalline CdS NPs that exhibit size-dependent optical properties due to quantum confinement of photogenerated e-h pairs as observed from UV-visible and photoluminescence spectroscopy and HRTEM microscopy measurements. The developed approach has obvious advantages comparatively to the alternative and more complex routes of production of composite materials with embedded semiconductor NPs because of the simplified one-pot preparative procedure used. The developed sol-gel process allows the control of the optical characteristics of the obtained CdS NPs embedded within the network by adjusting the molar ratio between cadmium ion and MPTMS and between cadmium and sulphide ions.

  16. Facile preparation of nanocubes zinc-based metal-organic framework by an ultrasound-assisted synthesis method; precursor for the fabrication of zinc oxide octahedral nanostructures.

    Science.gov (United States)

    Safarifard, Vahid; Morsali, Ali

    2018-01-01

    Synthesis of metal-organic framework (MOF) materials via ultrasound (US) irradiation involves shorter reaction times and offers enhanced control of particle size and morphology compared to conventional electric (CE) heating. Nanocubes of an interpenetrated pillared-layer Zn(II) metal-organic framework, [Zn2(NH2-BDC)2(4-bpdh)]·3DMF (TMU-16-NH2) (NH2-BDC=amino-1,4-benzenedicarboxylate, 4-bpdh=2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene, DMF=N,N-dimethylformamide), have been synthesized by US process and characterized by Field Emission Scanning Electron Microscopy (FE-SEM), powder X-ray diffraction, thermogravimetric analysis (TGA), elemental analysis and FTIR spectroscopy. The role of initial reagent concentrations and power levels of US irradiation and also reaction time, on size and morphology of nanostructure TMU-16-NH2 have been studied. Moreover, ZnO octahedral nanoparticles were simply prepared through direct pyrolysis of the TMU-16-NH2 nanocubes asa precursor at 520°C without any surfactant or capping molecules. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Preparation of weak-light-driven TiO2-based catalysts via adsorbed-layer nanoreactor synthesis and enhancement of their photo-degradation performance in seawater

    Science.gov (United States)

    Wang, Ting; Xu, Zhi-yong; Zhu, Yi-chen; Wu, Li-guang; Yuan, Hao-xuan; Li, Chang-chun; Liu, Ya-yu; Cai, Jing

    2017-11-01

    Graphene oxide (GO) was first employed as a support in preparing TiO2 nanoparticles by adsorbed-layer nanoreactor synthesis (ALNS). Both TiO2 crystallization and GO reduction simultaneously occurred during solvothermal treatment with alcohol as a solvent. By transmission electron microscopy, high resolution transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and photoluminescence spectroscopy, the results showed that TiO2 nanoparticles with less than 10 nm of size distributed very homogeneously on the GO surface. Tight interaction between TiO2 particles and GO surface could effectively inhibit the aggregation of TiO2 particles, during solvothermal treatment for anatase TiO2 formation. Alcohol could also reduce oxygenated functional groups on GO surface after solvothermal treatment. TiO2 particles with small size and the decrease in oxygenated functional groups on the GO surface both caused high separation efficiency of photo-generated charge carriers, thus resulting in high photo-degradation performance of catalysts. Strong phenol adsorption on photocatalyst was key to enhancing photo-degradation efficiency for phenol in seawater. Moreover, the change in catalyst structure was minimal at different temperatures of solvothermal treatment. But, the degradation rate and efficiency for phenol in seawater were obviously enhanced because of the sensitive structure-activity relationship of catalysts under weak-light irradiation.

  18. Direct hydrocarbon fuel cells

    Science.gov (United States)

    Barnett, Scott A.; Lai, Tammy; Liu, Jiang

    2010-05-04

    The direct electrochemical oxidation of hydrocarbons in solid oxide fuel cells, to generate greater power densities at lower temperatures without carbon deposition. The performance obtained is comparable to that of fuel cells used for hydrogen, and is achieved by using novel anode composites at low operating temperatures. Such solid oxide fuel cells, regardless of fuel source or operation, can be configured advantageously using the structural geometries of this invention.

  19. Glucose-coated superparamagnetic iron oxide nanoparticles prepared by metal vapour synthesis are electively internalized in a pancreatic adenocarcinoma cell line expressing GLUT1 transporter.

    Science.gov (United States)

    Barbaro, Daniele; Di Bari, Lorenzo; Gandin, Valentina; Evangelisti, Claudio; Vitulli, Giovanni; Schiavi, Eleonora; Marzano, Cristina; Ferretti, Anna M; Salvadori, Piero

    2015-01-01

    Iron oxide nanoparticles (IONP) can have a variety of biomedical applications due to their visualization properties through Magnetic Resonance Imaging (MRI) and heating with radio frequency or alternating magnetic fields. In the oncological field, coating IONP with organic compounds to provide specific features and to achieve the ability of binding specific molecular targets appears to be very promising. To take advantage of the high avidity of tumor cells for glucose, we report the development of very small glucose-coated IONP (glc-IONP) by employing an innovative technique, Metal Vapor Synthesis (MVS). Moreover, we tested the internalization of our gl-IONP on a tumor line, BxPC3, over-expressing GLUT 1 transporter. Both glc-IONP and polyvinylpyrrolidone-IONP (PVP-IONP), as control, were prepared with MVS and were tested on BxPC3 at various concentrations. To evaluate the role of GLUT-1 transporter, we also investigated the effect of adding a polyclonal anti-GLUT1 antibody. After proper treatment, the iron value was assessed by atomic absorption spectrometer, reported in mcg/L and expressed in mg of protein. Our IONP prepared with MVS were very small and homogeneously distributed in a narrow range (1.75-3.75 nm) with an average size of 2.7 nm and were super-paramagnetic. Glc-IONP were internalized by BxPC3 cells in a larger amount than PVP-IONP. After 6h of treatment with 50 mcg/mL of IONPs, the content of Fe was 1.5 times higher in glc-IONP-treated cells compared with PVP-IONP-treated cells. After 1h pre-treatment with anti-GLUT1, a reduction of 41% cellular accumulation of glc-IONP was observed. Conversely, the uptake of PVP-IONPs was reduced only by 14% with antibody pretreatment. In conclusion, MVS allowed us to prepare small, homogeneous, super-paramagnetic glc-IONP, which are electively internalized by a tumor line over-expressing GLUT1. Our glc-IONP appear to have many requisites for in vivo use.

  20. Glucose-coated superparamagnetic iron oxide nanoparticles prepared by metal vapour synthesis are electively internalized in a pancreatic adenocarcinoma cell line expressing GLUT1 transporter.

    Directory of Open Access Journals (Sweden)

    Daniele Barbaro

    Full Text Available Iron oxide nanoparticles (IONP can have a variety of biomedical applications due to their visualization properties through Magnetic Resonance Imaging (MRI and heating with radio frequency or alternating magnetic fields. In the oncological field, coating IONP with organic compounds to provide specific features and to achieve the ability of binding specific molecular targets appears to be very promising. To take advantage of the high avidity of tumor cells for glucose, we report the development of very small glucose-coated IONP (glc-IONP by employing an innovative technique, Metal Vapor Synthesis (MVS. Moreover, we tested the internalization of our gl-IONP on a tumor line, BxPC3, over-expressing GLUT 1 transporter. Both glc-IONP and polyvinylpyrrolidone-IONP (PVP-IONP, as control, were prepared with MVS and were tested on BxPC3 at various concentrations. To evaluate the role of GLUT-1 transporter, we also investigated the effect of adding a polyclonal anti-GLUT1 antibody. After proper treatment, the iron value was assessed by atomic absorption spectrometer, reported in mcg/L and expressed in mg of protein. Our IONP prepared with MVS were very small and homogeneously distributed in a narrow range (1.75-3.75 nm with an average size of 2.7 nm and were super-paramagnetic. Glc-IONP were internalized by BxPC3 cells in a larger amount than PVP-IONP. After 6h of treatment with 50 mcg/mL of IONPs, the content of Fe was 1.5 times higher in glc-IONP-treated cells compared with PVP-IONP-treated cells. After 1h pre-treatment with anti-GLUT1, a reduction of 41% cellular accumulation of glc-IONP was observed. Conversely, the uptake of PVP-IONPs was reduced only by 14% with antibody pretreatment. In conclusion, MVS allowed us to prepare small, homogeneous, super-paramagnetic glc-IONP, which are electively internalized by a tumor line over-expressing GLUT1. Our glc-IONP appear to have many requisites for in vivo use.

  1. THERMOCHEMISTRY OF HYDROCARBON RADICALS

    Energy Technology Data Exchange (ETDEWEB)

    Kent M. Ervin, Principal Investigator

    2004-08-17

    Gas phase negative ion chemistry methods are employed to determine enthalpies of formation of hydrocarbon radicals that are important in combustion processes and to investigate the dynamics of ion-molecule reactions. Using guided ion beam tandem mass spectrometry, we measure collisional threshold energies of endoergic proton transfer and hydrogen atom transfer reactions of hydrocarbon molecules with negative reagent ions. The measured reaction threshold energies for proton transfer yield the relative gas phase acidities. In an alternative methodology, competitive collision-induced dissociation of proton-bound ion-molecule complexes provides accurate gas phase acidities relative to a reference acid. Combined with the electron affinity of the R {center_dot} radical, the gas phase acidity yields the RH bond dissociation energy of the corresponding neutral molecule, or equivalently the enthalpy of formation of the R{center_dot} organic radical, using equation: D(R-H) = {Delta}{sub acid}H(RH) + EA(R) - IE(H). The threshold energy for hydrogen abstraction from a hydrocarbon molecule yields its hydrogen atom affinity relative to the reagent anion, providing the RH bond dissociation energy directly. Electronic structure calculations are used to evaluate the possibility of potential energy barriers or dynamical constrictions along the reaction path, and as input for RRKM and phase space theory calculations. In newer experiments, we have measured the product velocity distributions to obtain additional information on the energetics and dynamics of the reactions.

  2. Compounds and methods for the production of long chain hydrocarbons from biological sources

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, John Cameron; Silks, Louis A; Sutton, Andrew D; Wu, Ruilian; Schlaf, Marcel; Waldie, Fraser; West, Ryan; Collias, Dimitris Ioannis

    2016-08-23

    The present invention is directed to the preparation of oxygenated, unsaturated hydrocarbon compounds, such as derivatives of furfural or hydroxymethyl furfural produced by aldol condensation with a ketone or a ketoester, as well as methods of deoxidatively reducing those compounds with hydrogen under acidic conditions to provide saturated hydrocarbons useful as fuels.

  3. Preparation of standard mixtures of gas hydrocarbons in air by the diffusion dilution method; Preparacion de mezclas patrones de hidrocarburos gaseosos en aire por el metodo de dilucion por difusion

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, M. R.; Perez, M. M.

    1979-07-01

    An original diffusion system able to produce continuously gaseous samples is described. This system can generate samples with concentrations of benzene in air from 0.1 to 1 ppm a reproducible way. The diffusion dilution method used Is also studied. The use of this diffusion system has been extended to the preparation of binary mixtures (benzene-toluene). Whit a secondary dilution device is possible preparing these mixtures over a wide range of concentrations (0.11 to 0.04 ppm for benzene and 0.06 to 0.02 for toluene). (Author) 7 refs.

  4. Fire Synthesis

    Indian Academy of Sciences (India)

    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. Keywords. Alumina; combustion; refractory materials; urea. Author Affiliations. Tanu Mimani1.

  5. 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 ...

  6. Biodegradation testing of hydrophobic chemicals in mixtures at low concentrations – covering the chemical space of petroleum hydrocarbons

    DEFF Research Database (Denmark)

    Birch, Heidi; Hammershøj, Rikke Høst; Mayer, Philipp

    Petroleum products are complex mixtures of varying composition containing thousands of hydrocarbons each with their own physicochemical properties and degradation kinetics. One approach for risk assessment of these products is therefore to group the hydrocarbons by carbon number and chemical class...... of petroleum hydrocarbons, were therefore determined at ng/L to µg/L concentrations in surface water, seawater and activated sludge filtrate. Two hydrocarbon mixtures were prepared, comprising a total of 53 chemicals including paraffins, naphthenics and aromatic hydrocarbons from C8 to C20. Passive dosing from...

  7. Total synthesis of aeruginazole A

    OpenAIRE

    Bruno, Paolo; Peña, Stella; Just Baringo, Xavier; Albericio Palomera, Fernando; Álvarez Domingo, Mercedes

    2011-01-01

    The first total synthesis of Aeruginazole A, prepared via a convergent strategy that involved both solid-phase peptide synthesis and solution phase chemistry and that enabled conservation of the stereochemistry of the intermediates, is reported.

  8. Methods for estimating properties of hydrocarbons comprising asphaltenes based on their solubility

    Science.gov (United States)

    Schabron, John F.; Rovani, Jr., Joseph F.

    2016-10-04

    Disclosed herein is a method of estimating a property of a hydrocarbon comprising the steps of: preparing a liquid sample of a hydrocarbon, the hydrocarbon having asphaltene fractions therein; precipitating at least some of the asphaltenes of a hydrocarbon from the liquid sample with one or more precipitants in a chromatographic column; dissolving at least two of the different asphaltene fractions from the precipitated asphaltenes during a successive dissolution protocol; eluting the at least two different dissolved asphaltene fractions from the chromatographic column; monitoring the amount of the fractions eluted from the chromatographic column; using detected signals to calculate a percentage of a peak area for a first of the asphaltene fractions and a peak area for a second of the asphaltene fractions relative to the total peak areas, to determine a parameter that relates to the property of the hydrocarbon; and estimating the property of the hydrocarbon.

  9. Seawater-cultured Botryococcus braunii for efficient hydrocarbon extraction.

    Directory of Open Access Journals (Sweden)

    Kenichi Furuhashi

    Full Text Available As a potential source of biofuel, the green colonial microalga Botryococcus braunii produces large amounts of hydrocarbons that are accumulated in the extracellular matrix. Generally, pretreatment such as drying or heating of wet algae is needed for sufficient recoveries of hydrocarbons from B. braunii using organic solvents. In this study, the Showa strain of B. braunii was cultured in media derived from the modified Chu13 medium by supplying artificial seawater, natural seawater, or NaCl. After a certain period of culture in the media with an osmotic pressure corresponding to 1/4-seawater, hydrocarbon recovery rates exceeding 90% were obtained by simply mixing intact wet algae with n-hexane without any pretreatments and the results using the present culture conditions indicate the potential for hydrocarbon milking.Seawater was used for efficient hydrocarbon extraction from Botryococcus braunii. The alga was cultured in media prepared with seawater or NaCl. Hydrocarbon recovery rate exceeding 90% was obtained without any pretreatment.

  10. Seawater-Cultured Botryococcus braunii for Efficient Hydrocarbon Extraction

    Science.gov (United States)

    Furuhashi, Kenichi; Saga, Kiyotaka; Okada, Shigeru; Imou, Kenji

    2013-01-01

    As a potential source of biofuel, the green colonial microalga Botryococcus braunii produces large amounts of hydrocarbons that are accumulated in the extracellular matrix. Generally, pretreatment such as drying or heating of wet algae is needed for sufficient recoveries of hydrocarbons from B. braunii using organic solvents. In this study, the Showa strain of B. braunii was cultured in media derived from the modified Chu13 medium by supplying artificial seawater, natural seawater, or NaCl. After a certain period of culture in the media with an osmotic pressure corresponding to 1/4-seawater, hydrocarbon recovery rates exceeding 90% were obtained by simply mixing intact wet algae with n-hexane without any pretreatments and the results using the present culture conditions indicate the potential for hydrocarbon milking. Highlights Seawater was used for efficient hydrocarbon extraction from Botryococcus braunii. The alga was cultured in media prepared with seawater or NaCl. Hydrocarbon recovery rate exceeding 90% was obtained without any pretreatment. PMID:23799107

  11. Structure and topology of three-dimensional hydrocarbon polymers.

    Science.gov (United States)

    Kondrin, Mikhail V; Lebed, Yulia B; Brazhkin, Vadim V

    2016-08-01

    A new family of three-dimensional hydrocarbon polymers which are more energetically favorable than benzene is proposed. Although structurally these polymers are closely related to well known diamond and lonsdaleite carbon structures, using topological arguments we demonstrate that they have no known structural analogs. Topological considerations also give some indication of possible methods of synthesis. Taking into account their exceptional optical, structural and mechanical properties these polymers might have interesting applications.

  12. Fischer-Tropsch synthesis over MOF-supported cobalt catalysts (Co@MIL-53(Al)).

    Science.gov (United States)

    Isaeva, V I; Eliseev, O L; Kazantsev, R V; Chernyshev, V V; Davydov, P E; Saifutdinov, B R; Lapidus, A L; Kustov, L M

    2016-07-26

    Novel nanohybrid materials were prepared by immobilizing Co nanoparticles on a microporous framework MIL-53(Al) as a porous host matrix. The synthesized cobalt-containing materials were characterized by XRD, STEM, and oxygen titration. The catalytic performance of Co@MIL-53(Al) nanohybrids was examined in Fischer-Tropsch synthesis (FTS) for the first time. A higher selectivity to C5+ hydrocarbons and lower selectivity to methane for Co@MIL-53(Al) as compared to conventional Co/Al2O3 were observed.

  13. Thermophysical Properties of Hydrocarbon Mixtures

    Science.gov (United States)

    SRD 4 NIST Thermophysical Properties of Hydrocarbon Mixtures (PC database for purchase)   Interactive computer program for predicting thermodynamic and transport properties of pure fluids and fluid mixtures containing up to 20 components. The components are selected from a database of 196 components, mostly hydrocarbons.

  14. Phenyltrichlorosilane-functionalized magnesium oxide microspheres: Preparation, characterization and application for the selective extraction of dioxin-like polycyclic aromatic hydrocarbons in soils with matrix solid-phase dispersion

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Dongqin [Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, No. 457 Zhongshan Road, Dalian 116023 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Jin, Jing [Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, No. 457 Zhongshan Road, Dalian 116023 (China); Li, Fang [Shenzhen Institutes of Advanced Technology, Chinese Academy of Science, Shenzhen 518055 (China); Sun, Xiaoli [Department of Chemistry, Lishui University, Lishui 32300 (China); Dhanjai; Ni, Yuwen [Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, No. 457 Zhongshan Road, Dalian 116023 (China); Chen, Jiping, E-mail: chenjp@dicp.ac.cn [Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, No. 457 Zhongshan Road, Dalian 116023 (China)

    2017-03-01

    Magnesium oxide microspheres functionalized with phenyltrichlorosilane (PTS-MgO) were synthesized by surface modification through silanization reaction, which was confirmed by Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetry analysis (TGA) and N{sub 2} adsorption-desorption. The result indicated that PTS-MgO not only possessed the ability of enhancing the retention with PAHs, but also weakening the interference from chlorinated compounds. As a sorbent for the matrix solid-phase dispersion (MSPD) extraction, PTS-MgO was used to selectively extract seven dioxin-like polycyclic aromatic hydrocarbons (DL-PAHs) from soil samples. Various parameters affecting the recoveries of seven DL-PAHs were investigated and optimized, such as sorbent/sample mass ratio, grinding time, rinsing and eluting conditions. Under the optimized conditions, the developed method combining MSPD with HPLC-FLD exhibited good sensitivity (0.02–0.12 ng g{sup −1} detection of limits) and linearity (linear correlation coefficient greater than 0.9997). Satisfactory recoveries with DL-PAHs spiked at two levels (10 and 80 ng g{sup −1}) were obtained in the range of 72.2–113.1% with RSD < 9.6%, indicating that PTS-MgO had a potential in MSPD extraction of DL-PAHs in soils. Additionally, the proposed MSPD-HPLC-FLD method was also verified by detecting seven DL-PAHs in the standard reference soil. Based on the developed method, DL-PAHs in soil samples were detected with the concentration ranging from 70.08 to 555.05 ng g{sup −1} dry weight (dw). The total toxic equivalency quotients (TEQ) of seven DL-PAHs varied from 9.93 to 143.94 ng TEQ/g dw. - Highlights: • Phenyltrichlorosilane modified magnesium oxide microsphere (PTS-MgO) was presented. • PTS-MgO was used for a new sorbent material in matrix solid-phase dispersion. • The sorbent showed high selectivity for DL-PAHs with satisfactory recoveries obtained. • The

  15. Hydrocarbon polymeric binder for advanced solid propellant

    Science.gov (United States)

    Potts, J. E. (Editor)

    1972-01-01

    A series of DEAB initiated isoprene polymerizations were run in the 5-gallon stirred autoclave reactor. Polymerization run parameters such as initiator concentration and feed rate were correlated with the molecular weight to provide a basis for molecular weight control in future runs. Synthetic methods were developed for the preparation of n-1,3-alkadienes. By these methods, 1,3-nonadiene was polymerized using DEAB initiator to give an ester-telechelic polynonadiene. This was subsequently hydrogenated with copper chromite catalyst to give a hydroxyl terminated saturated liquid hydrocarbon prepolymer having greatly improved viscosity characteristics and a Tg 18 degrees lower than that of the hydrogenated polyisoprenes. The hydroxyl-telechelic saturated polymers prepared by the hydrogenolysis of ester-telechelic polyisoprene were reached with diisocyanates under conditions favoring linear chain extension gel permeation chromatography was used to monitor this condensation polymerization. Fractions having molecular weights above one million were produced.

  16. In vitro toxicity of polycyclic aromatic hydrocarbons and halogenated aromatic hydrocarbons to cetacean cells and tissues

    Energy Technology Data Exchange (ETDEWEB)

    Carvan, M.J. III.

    1993-01-01

    Cetaceans bioaccumulate high aromatic hydrocarbon tissue residues, and elevated levels of PCB residues in tissues are proposed to have occurred concurrently with recent epizootic deaths of dolphins. The objectives of this study were: (1) to develop and characterize an epithelial cell line derived from dolphin tissues, (2) to investigate the effects of hydrocarbon pollutants on those cells, and (3) to analyze the toxicity of hydrocarbon pollutants on cetacean tissues in vitro. An epithelial cell line, Carvan dolphin kidney (CDK), isolated from a spontaneously aborted female bottlenose dolphin, Tursiops truncatus, grew rapidly. These cells were neither transformed nor immortal. Velocity sedimentation analysis showed CDK cells contained nuclear aryl hydrocarbon receptor, suggestive of cytochrome P450 inducibility. BaP inhibited mitosis in CDK cells in a dose-dependent manner. Data indicate that CDK cells metabolize BaP, that BaP metabolites bind to cellular DNA initiating unscheduled DNA synthesis, and that the inhibition of cytochrome P450 metabolism decrease the BaP-associated inhibition of mitosis in dolphin cells. The data also suggest that TCDD acts synergistically to increase the levels of DNA damage by the procarcinogen BaP. Cetacean liver microsomes was isolated and evaluated for the presence of cytochrome P450 proteins by SDS-PAGE, apparent minimum molecular weight determination, and immunoblot analysis. P450 activity was induced in cetacean tissue samples and CDK cells by exposure in vitro to one of several cytochrome P450-inducing chemicals. The data suggest that cetacean tissues and cells can be utilized to study the in vitro induction of cytochrome P450, resultant metabolism of xenobiotic contaminants, and the subsequent cellular and molecular responses. However, the identity of specific P450 isozymes involved in this process will remain undetermined until monoclonal antibodies that recognize cetacean P450s can be generated.

  17. Pyrochlore catalysts for hydrocarbon fuel reforming

    Science.gov (United States)

    Berry, David A.; Shekhawat, Dushyant; Haynes, Daniel; Smith, Mark; Spivey, James J.

    2012-08-14

    A method of catalytically reforming a reactant gas mixture using a pyrochlore catalyst material comprised of one or more pyrochlores having the composition A2B2-y-zB'yB"zO7-.DELTA., where y>0 and z.gtoreq.0. Distribution of catalytically active metals throughout the structure at the B site creates an active and well dispersed metal locked into place in the crystal structure. This greatly reduces the metal sintering that typically occurs on supported catalysts used in reforming reactions, and reduces deactivation by sulfur and carbon. Further, oxygen mobility may also be enhanced by elemental exchange of promoters at sites in the pyrochlore. The pyrochlore catalyst material may be utilized in catalytic reforming reactions for the conversion of hydrocarbon fuels into synthesis gas (H2+CO) for fuel cells, among other uses.

  18. SYNTHESIS OF 6-NITRO VERATRYL ALCOHOL AND 6-NITRO VERATRALDOXIM FROM VANILIN AS INTERMEDIATES FOR THE PREPARATION OF C-9154 ANTIBIOTIC DERVATIVES

    Directory of Open Access Journals (Sweden)

    Jumina Jumina

    2010-06-01

    Full Text Available The synthesis of 6-nitro veratryl alcohol and 6-nitro veratraldoxim from vanilin which was required as intermediates for the preparation of C-9154 antibiotic derivatives was carried out. C-9154 antibiotic is a sufficiently potent antibiotic, but so far this is produced only in low yields through microbiological processes. The reaction steps performed were (1 methylation of vanilin, (2 nitration of the methylation product, (3 reduction of the corresponding nitro compound and (4 reaction of the nitration product with HO-NH2.HCl. Methylation of vanilin was conducted using dimethylsulfate and NaOH at 60 oC for 2 hours. Nitration of the methylation product was performed in 2 methods, i.e. using neat HNO3 and using a mixture of HNO3 and H2SO4 both at 5 oC for 2 hours. Reduction of the nitration product was conducted using NaBH4 either at room temperature and at reflux. Reaction of the nitration product with HO-NH2.HCl was carried out in ethanol 95% at 50 oC for 2 hours. The products were analyzed by means of TLC, GC, IR, 1H NMR and GC-MS spectrometers. The methylation of vanilin gave 87.7% yield of veratraldehyde which was found as a white crystal (m.p 43 oC. The nitration of veratraldehyde produced 6-nitro veratraldehyde observed as a yellow crystal having of m.p. 130 oC. Nitration using neat HNO3 gave a smaller yield (50.35% of 6-nitro veratraldehyde than nitration with a mixture of HNO3 and H2SO4 (93.63%. Reduction of 6-nitro veratraldehyde using NaBH4 at room temperature and at reflux afforded 6-nitro veratryl alcohol which was found as brown crystal (m.p 123-127 oC respectively in 13.47% and 56.61%. This reduction also produced 6-amino veratryl alcohol and 3,4-dimethoxy benzoic zcid as by products. 6-Nitro veratraldehyde reacts with HO-NH2.HCl to give 6-nitro veratraldoxim in 48.27% yield.   Keywords: antibiotics, veratril alcohol, veratraldoxim vanilin

  19. Saccharide-derived microporous spherical biochar prepared from hydrothermal carbonization and different pyrolysis temperatures: synthesis, characterization, and application in water treatment.

    Science.gov (United States)

    Tran, Hai Nguyen; Lee, Chung-Kung; Nguyen, Tien Vinh; Chao, Huan-Ping

    2017-08-24

    Three saccharides (glucose, sucrose, and xylose) were used as pure precursors for synthesizing spherical biochars (GB, SB, and XB), respectively. The two-stage synthesis process comprised: (1) the hydrothermal carbonization of saccharides to produce spherical hydrochar' and (2) pyrolysis of the hydrochar at different temperatures from 300°C to 1200°C. The results demonstrated that the pyrolysis temperatures insignificantly affected the spherical morphology and surface chemistry of biochar. The biochar' isoelectric point ranged from 2.64 to 3.90 (abundant oxygen-containing functionalities). The Brunauer-Emmett-Teller (BET)-specific surface areas (SBET) and total pore volumes (Vtotal) of biochar increased with the increasing pyrolysis temperatures. The highest SBET and Vtotal were obtained at a pyrolysis temperature of 900°C for GB (775 m2/g and 0.392 cm3/g), 500°C for SB (410 m2/g and 0.212 cm3/g), and 600°C for XB (426 m2/g and 0.225 cm3/g), respectively. The spherical biochar was a microporous material with approximately 71-98% micropore volume. X-ray diffraction results indicated that the biochar' structure was predominantly amorphous. The spherical biochar possessed the graphite structure when the pyrolysis temperature was higher than 600°C. The adsorption capacity of GB depended strongly on the pyrolysis temperature. The maximum Langmuir adsorption capacities ([Formula: see text]) of 900GB exhibited the following selective order: phenol (2.332 mmol/g) > Pb2+ (1.052 mmol/g) > Cu2+ (0.825 mmol/g) > methylene green 5 (0.426 mmol/g) > acid red 1 (0.076 mmol/g). This study provides a simple method to prepare spherical biochar - a new and potential adsorbent for adsorbing heavy metals and aromatic contaminants.

  20. Enabling the synthesis of medium chain alkanes and 1-alkenes in yeast

    DEFF Research Database (Denmark)

    Zhu, Zhiwei; Zhou, Yongjin J.; Kang, Min Kyoung

    2017-01-01

    Microbial synthesis of medium chain aliphatic hydrocarbons, attractive drop-in molecules to gasoline and jet fuels, is a promising way to reduce our reliance on petroleum-based fuels. In this study, we enabled the synthesis of straight chain hydrocarbons (C7–C13) by yeast Saccharomyces cerevisiae...

  1. Total synthesis of a CD-ring: side-chain building block for preparing 17-epi-calcitriol derivatives from the Hajos-Parrish dione.

    Science.gov (United States)

    Michalak, Karol; Wicha, Jerzy

    2011-08-19

    An efficient synthesis of the key building block for 17-epi-calctriol from the Hajos-Parrish dione involving a sequence of diastereoselective transformation of the azulene core and the side-chain construction is presented.

  2. KINETICS OF THE GAS-SLURRY METHANOL-HIGHER ALCOHOL SYNTHESIS FROM CO/CO2/H-2 OVER A CS-CU/ZNO/AL2O3 CATALYST, INCLUDING SIMULTANEOUS FORMATION OF METHYL-ESTERS AND HYDROCARBONS

    NARCIS (Netherlands)

    BREMAN, BB; BEENACKERS, AACM; SCHUURMAN, HA; OESTERHOLT, E

    1995-01-01

    First kinetic results are presented for the gas-slurry methanol-higher alcohol synthesis from CO/CO2/H-2 (syngas) over a CU0.44Zn0.43Al0.12Cs0.031 catalyst (particle size: 50-75 mu m), slurried in n-octacosane. Experimental conditions varied as follows: pressure = 20-80 bar, temperature = 473-573 K,

  3. Comparison of anticancer activity of biocompatible ZnO nanoparticles prepared by solution combustion synthesis using aqueous leaf extracts of Abutilon indicum, Melia azedarach and Indigofera tinctoria as biofuels.

    Science.gov (United States)

    Prashanth, G K; Prashanth, P A; Nagabhushana, B M; Ananda, S; Krishnaiah, G M; Nagendra, H G; Sathyananda, H M; Rajendra Singh, C; Yogisha, S; Anand, S; Tejabhiram, Y

    2017-07-18

    Recently, there has been an upsurge in the use of naturally available fuels for solution combustion synthesis (SCS) of nanoparticles. Although many reports suggest that these biofuels pose less harm to the environment, their strategic advantages and reliability for making NPs has not been discussed. In the present work, we try to address this issue using plant extracts as biofuels for the SCS of zinc oxide nanoparticles as a model system. In the present work, combustion synthesis of ZnO NPs using lactose and aqueous leaf extracts of Abutilon indicum, Melia azedarach, Indigofera tinctoria as biofuels has been carried out. A comparative analysis of the obtained powders has been conducted to understand the strategic advantages of using plant extracts over a chemical as combustion fuel for the synthesis of zinc oxide nanoparticles. The X-ray diffractograms of the samples revealed the presence of Wurtzite hexagonal structure with varying crystallite sizes. Morphological studies indicated that samples prepared using biofuels had smaller diameter than those prepared using lactose as fuel. Surface characteristics of the samples were measured by X-ray photoelectron spectroscopy. Qualitative phytochemical screening of aqueous leaf extracts revealed the presence of many phytochemicals in them, which might be responsible for combustion. Gas chromatography mass spectrum was carried out to detect the phytochemicals present in the aqueous extracts of the leaves. Further, anticancer evaluation carried out against DU-145 and Calu-6 cancer cells indicated higher anticancer activity of zinc oxide nanoparticles prepared using biofuels. The results of blood haemolysis revealed the biocompatibility of zinc oxide nanoparticles at lower concentrations. In conclusion, we propose that multiple other studies would be required in order to vindicate the potential advantages of using naturally available fuels in SCS.

  4. Effect of the porous structure of the support on hydrocarbon distribution in the Fischer-Tropsch reaction

    Science.gov (United States)

    Bartolini, Monica; Molina, Jhoanna; Alvarez, Juan; Goldwasser, Mireya; Pereira Almao, Pedro; Zurita, M. Josefina Pérez

    2015-07-01

    Emissions standards are increasingly stringent due mainly to its impact on the environment. Although the diesel engine is an attractive solution for carbon dioxide reduction, a challenge remains to simultaneously control nitrogen oxides and matter particulate emissions to accepted levels. On engine tests, it has been observed that Fischer-Tropsch diesel significantly reduces CO, HC, PAHs and particulate emissions compared to oil derived diesel. However, selectivity control in Fischer Tropsch Synthesis is still a key challenge due the Anderson-Schultz-Flory polymerization mechanism followed by hydrocarbon distribution. In this work we are presenting the first steps towards a new strategy that can tune, in one step, the selectivity to desired products by taking advantage of the shape selectivity properties of SBA-15 mesoporous silica used as support. Co-SBA-15 (30%wt) catalysts with different pore size were prepared by excess solution impregnation. Our results show that pore diameter not only affects the size and reducibility of Co particles but it also significantly influence the liquid products distribution, with the high molecular weight hydrocarbon fraction increasing on large pores, attributed to the existence of a shape selectivity effect induced by the textural properties of the catalyst namely its pore size and pore volume.

  5. DETERMINATION OF POLYCYCLIC AROMATIC HYDROCARBONS ...

    African Journals Online (AJOL)

    AMOS

    Scomber scombrus), suya beef and plantain (Musa paradiasca) sold and consumed in Amassoma town were screened for the presence of 15 polycyclic aromatic hydrocarbons (PAHs). Concentration of chromium, lead and cadmium were also ...

  6. Growth of hydrocarbon utilizing microorganisms

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Mavinkurve, S.

    Two isolates from marine mud having broad spectrum hydrocarbon utilizing profile were identified as Arthrobacter simplex and Candida tropicalis.Both the organisms grew exponentially on crude oil. The cell yield of the organisms was influenced...

  7. Hydrocarbon Leak Detection Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — FTT is proposing the development of a sensor to detect the presence of hydrocarbons in turbopump Inter-Propellant Seals (IPS). The purpose of the IPS is to prevent...

  8. Aliphatic hydrocarbons of the fungi.

    Science.gov (United States)

    Weete, J. D.

    1972-01-01

    Review of studies of aliphatic hydrocarbons which have been recently detected in the spores of phytopathogenic fungi, and are found to be structurally very similar to the alkanes of higher plants. It appears that the hydrocarbon components of the few mycelial and yeast forms reported resemble the distribution found in bacteria. The occurence and distribution of these compounds in the fungi is discussed. Suggested functional roles of fungal spore alkanes are presented.

  9. Separation of aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Grishchenko, N.F.; Yablochkina, M.N.; Shapiro, L.P.; Rogozkin, V.A.

    1979-01-01

    An optimal system of extraction has been developed making it possible to produce benzene, toluene and xylenes economically and with high efficiency.The raw material used for catalytic reforming consists of narrow-boiling-range gasoline fractiions at 62 to 85, 62 to 105 and 105 to 140/sup 0/C. Processing of the first fraction makes it possible to produce benzene; the second, benzene and toluene; and the third, toluene and xylenes. The addition of reforming extraction units has made it possible to produce aromatic hydrocarbons suitable for any specialized application. At the current time the output of benzene with extraction plants is about 60 percent of the total output, of toluene more than 80 percent and of xylene more than 50 percent. The key technological indicators are given for the processes of extraction with hydrous polyglycols. For new higher-capacity plants, in addition to extraction with tetraethylene glycol, the 'Ekstars' process has been developed for extraction with a hybrid solvent based on propylene carbonate. For eliminating the presence of unsaturated compounds, a process has been developed for the selective hydrogenation of reforming catalysis products. The process is carried out in an additional reactor included in the catalytic reforming system, at 160 to 250/sup 0/C with an aluminoplatinic catalyst in a combined steam and gas mixture flow at a pressure of 1.5 to 3.5 MPa. (JMT)

  10. Evaluation of hydrocarbon potential

    Energy Technology Data Exchange (ETDEWEB)

    Cashman, P.H.; Trexler, J.H. Jr. [Univ. of Nevada, Reno, NV (United States)

    1992-09-30

    Task 8 is responsible for assessing the hydrocarbon potential of the Yucca Mountain vincinity. Our main focus is source rock stratigraphy in the NTS area in southern Nevada. (In addition, Trexler continues to work on a parallel study of source rock stratigraphy in the oil-producing region of east central Nevada, but this work is not funded by Task 8.) As a supplement to the stratigraphic studies, we are studying the geometry and kinematics of deformation at NTS, particularly as these pertain to reconstructing Paleozoic stratigraphy and to predicting the nature of the Late Paleozoic rocks under Yucca Mountain. Our stratigraphic studies continue to support the interpretation that rocks mapped as the {open_quotes}Eleana Formation{close_quotes} are in fact parts of two different Mississippian units. We have made significant progress in determining the basin histories of both units. These place important constraints on regional paleogeographic and tectonic reconstructions. In addition to continued work on the Eleana, we plan to look at the overlying Tippipah Limestone. Preliminary TOC and maturation data indicate that this may be another potential source rock.

  11. On the anomalies in gold nanoparticles prepared by micelle nanolithography and their impact on one-dimensional material synthesis. Role of substrate, size effects and impurity

    Energy Technology Data Exchange (ETDEWEB)

    Mbenkum, B.N.

    2007-07-23

    The synthesis of one-dimensional (1-D) inorganic semiconductor materials such as nanotubes and silicon (Si) nanowires is usually achieved by catalyst nanoparticlemediated synthetic routes. Despite the well-established nature of this technique, problems such as low temperature synthesis and adequate control of catalyst nanoparticle diameter in order to control 1-D material diameter still prevail. Additionally, the expansion of this technology from crystalline to cheaper substrates such as glass remains demanding. This work employs a previously established selfassembly route to produce controlled spatial distribution of substrate anchored small diameter gold nanoparticles with controlled size. This enabled successful synthesis of Si 1-D structures with controlled diameters less than 20 nm. Low temperature synthesis due to enhanced catalytic activity was achieved via introduction of impurity by treatment of gold nanoparticles in different plasma environments. This enabled Si 1-D structure growth on Si, SiO{sub x}/Si and borosilicate glass substrates at 320 C. Substrate-induced stress affected Si diffusion at the gold nanoparticle determining whether Si nanowires or nanotubes were grown. These results are of technological relevance because low temperature synthesis provides an economical approach and controlled diameter enhances material functionality. Additionally, exploiting substrate-induced stress to influence Si diffusion in nanoparticles provides an alternate route to tuning Si 1-D structure. (orig.)

  12. Fluoride-assisted synthesis of bimodal microporous SSZ-13 zeolite

    NARCIS (Netherlands)

    Zhu, Xiaochun; Kosinov, Nikolay; Hofmann, Jan P.; Mezari, Brahim; Qian, Qingyun; Rohling, Roderigh; Weckhuysen, Bert M.; Ruiz-Martinez, Javier; Hensen, Emiel J. M.

    The presence of small amount of fluoride in alkaline hydrothermal synthesis of SSZ-13 zeolite yields bimodal microporous particles with substantially improved performance in the methanol-to-olefins (MTO) reaction. Hydrocarbon uptake measurements and fluorescence microspectroscopy of spent catalysts

  13. Improved ZIF-8 membrane: Effect of activation procedure and determination of diffusivities of light hydrocarbons

    KAUST Repository

    Pan, Yichang

    2015-06-23

    Zeolitic imidazolate framework ZIF-8 has shown great potential for effective separation of hydrocarbon mixtures based on its intrinsic ultramicroporous feature. In order to explore the permeation and diffusion properties of hydrocarbons through ZIF-8 membrane, high-quality ZIF-8 membranes with a separation factor of ~90 for propylene/propane are successfully prepared via optimizing the activation processes. Single-component permeation data for hydrocarbons (C1–C4) through the improved ZIF-8 membrane are measured and analyzed by Maxwell-Stefan (MS) model to get the transport diffusivities of these hydrocarbons. The diffusivity values of hydrocarbon compare well with those obtained by other experimental techniques. Binary mixture permeation also can be well predicted through single-component adsorption parameters.

  14. Evaluation of mineral oil saturated hydrocarbons (MOSH) and mineral oil aromatic hydrocarbons (MOAH) in pure mineral hydrocarbon-based cosmetics and cosmetic raw materials using (1)H NMR spectroscopy.

    Science.gov (United States)

    Lachenmeier, Dirk W; Mildau, Gerd; Rullmann, Anke; Marx, Gerhard; Walch, Stephan G; Hartwig, Andrea; Kuballa, Thomas

    2017-01-01

    Mineral hydrocarbons consist of two fractions, mineral oil saturated hydrocarbons (MOSH) and mineral oil aromatic hydrocarbons (MOAH). MOAH is a potential public health hazard because it may include carcinogenic polycyclic compounds. In the present study, 400 MHz nuclear magnetic resonance (NMR) spectroscopy was introduced, in the context of official controls, to measure MOSH and MOAH in raw materials or pure mineral hydrocarbon final products (cosmetics and medicinal products). Quantitative determination (qNMR) has been established using the ERETIC methodology (electronic reference to access in vivo concentrations) based on the PULCON principle (pulse length based concentration determination). Various mineral hydrocarbons (e.g., white oils, paraffins or petroleum jelly) were dissolved in deuterated chloroform. The ERETIC factor was established using a quantification reference sample containing ethylbenzene and tetrachloronitrobenzene. The following spectral regions were integrated: MOSH δ 3.0 - 0.2 ppm and MOAH δ 9.2 - 6.5, excluding solvent signals. Validation showed a sufficient precision of the method with a coefficient of variation hydrocarbon raw materials or pure mineral hydrocarbon-based cosmetic products, NMR delivers higher specificity without any sample preparation besides dilution. Our sample survey shows that previous methods may have overestimated the MOAH amount in mineral oil products and opens new paths to characterize this fraction. Therefore, the developed method can be applied for routine monitoring of consumer products aiming to minimize public health risks.

  15. Polycyclic Aromatic Hydrocarbons

    Science.gov (United States)

    Salama, Farid

    2010-01-01

    Carbonaceous materials play an important role in space. Polycyclic Aromatic Hydrocarbons (PAHs) are a ubiquitous component of the carbonaceous materials. PAHs are the best-known candidates to account for the IR emission bands. They are also thought to be among the carriers of the diffuse interstellar absorption bands (DIBs). PAH ionization states reflect the ionization balance of the medium while PAH size, composition, and structure reflect the energetic and chemical history of the medium. A major challenge is to reproduce in the laboratory the physical conditions that exist in the emission and absorption interstellar zones. The harsh physical conditions of the ISM -low temperature, collisionless, strong UV radiation fields- are simulated in the laboratory by associating a molecular beam with an ionizing discharge to generate a cold plasma expansion. PAH ions and radicals are formed from the neutral precursors in an isolated environment at low temperature and probed with high-sensitivity cavity ringdown spectroscopy in the NUV-NIR range. Carbon nanoparticles are also formed during the short residence time of the precursors in the plasma and are characterized with time-offlight mass spectrometry. These experiments provide unique information on the spectra of large carbonaceous molecules and ions in the gas phase that can now be directly compared to interstellar and circumstellar observations (IR emission bands, DIBs, extinction curve). These findings also hold great potential for understanding the formation process of interstellar carbonaceous grains. We will review recent progress in the experimental and theoretical studies of PAHs, compare the laboratory data with astronomical observations and discuss the global implications.

  16. Semi-synthesis of murine prion protein by native chemical ligation and chemical activation for preparation of polypeptide-α-thioester.

    Science.gov (United States)

    Shi, Lei; Chen, Huai; Zhang, Si-Yu; Chu, Ting-Ting; Zhao, Yu-Fen; Chen, Yong-Xiang; Li, Yan-Mei

    2017-06-01

    Prions are suspected as pathogen of the fatal transmissible spongiform encephalopathies. Strategies to access homogenous prion protein (PrP) are required to fully comprehend the molecular mechanism of prion diseases. However, the polypeptide fragments from PrP show a high tendency to form aggregates, which is a gigantic obstacle of protein synthesis and purification. In this study, murine prion sequence 90 to 230 that is the core three-dimensional structure domain was constructed from three segments murine PrP (mPrP)(90-177), mPrP(178-212), and mPrP(213-230) by combining protein expression, chemical synthesis and chemical ligation. The protein sequence 90 to 177 was obtained from expression and finally converted into the polypeptide hydrazide by chemical activation of a cysteine in the tail. The other two polypeptide fragments of the C-terminal were obtained by chemical synthesis, which utilized the strategies of isopeptide and pseudoproline building blocks to complete the synthesis of such difficult sequences. The three segments were finally assembled by sequentially using native chemical ligation. This strategy will allow more straightforward access to homogeneously modified PrP variants. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.

  17. Towards ‘greener’ catalyst manufacture: Reduction of wastewater from the preparation of Cu/ZnO/Al2O3 methanol synthesis catalysts

    NARCIS (Netherlands)

    Prieto, G.; de Jong, K.P.|info:eu-repo/dai/nl/06885580X; de Jongh, P.E.|info:eu-repo/dai/nl/186125372

    2013-01-01

    The generation of large volumes of nitrate-containing wastewater is a major issue in the industrial production of solid catalysts such as Cu/ZnO/Al2O3 employed in methanol synthesis. Extensive washing with water is needed to remove nitrate (and sodium) residues in the as-precipitated metal

  18. Subfemtosecond steering of hydrocarbon deprotonation through superposition of vibrational modes

    Science.gov (United States)

    Alnaser, A. S.; Kübel, M.; Siemering, R.; Bergues, B.; Kling, Nora G.; Betsch, K. J.; Deng, Y.; Schmidt, J.; Alahmed, Z. A.; Azzeer, A. M.; Ullrich, J.; Ben-Itzhak, I.; Moshammer, R.; Kleineberg, U.; Krausz, F.; de Vivie-Riedle, R.; Kling, M. F.

    2014-05-01

    Subfemtosecond control of the breaking and making of chemical bonds in polyatomic molecules is poised to open new pathways for the laser-driven synthesis of chemical products. The break-up of the C-H bond in hydrocarbons is an ubiquitous process during laser-induced dissociation. While the yield of the deprotonation of hydrocarbons has been successfully manipulated in recent studies, full control of the reaction would also require a directional control (that is, which C-H bond is broken). Here, we demonstrate steering of deprotonation from symmetric acetylene molecules on subfemtosecond timescales before the break-up of the molecular dication. On the basis of quantum mechanical calculations, the experimental results are interpreted in terms of a novel subfemtosecond control mechanism involving non-resonant excitation and superposition of vibrational degrees of freedom. This mechanism permits control over the directionality of chemical reactions via vibrational excitation on timescales defined by the subcycle evolution of the laser waveform.

  19. Two-step processing of oil shale to linear hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Eliseev, O.L.; Ryzhov, A.N.; Latypova, D.Zh.; Lapidus, A.L. [Russian Academy of Sciences, Moscow (Russian Federation). N.D. Zelinsky Institute of Organic Chemistry; Avakyan, T.A. [Gubkin Russian State University of Oil and Gas, Moscow (Russian Federation)

    2013-11-01

    Thermal and catalytic steam reforming of oil shale mined from Leningrad and Kashpir deposits was studied. Experiments were performed in fixed bed reactor by varying temperature and steam flow rate. Data obtained were approximated by empirical formulas containing some parameters calculated by least-squares method. Thus predicting amount of hydrogen, carbon monoxide and methane in producer gas is possible for given particular kind of oil shale, temperature and steam flow rate. Adding Ni catalyst enriches hydrogen and depletes CO content in effluent gas at low gasification temperatures. Modeling gas simulating steam reforming gases (H{sub 2}, CO, CO{sub 2}, and N{sub 2} mixture) was tested in hydrocarbon synthesis over Co-containing supported catalyst. Selectivity of CO conversion into C{sub 5+} hydrocarbons reaches 84% while selectivity to methane is 7%. Molecular weight distribution of synthesized alkanes obeys Anderson-Schulz-Flory equation and chain growth probability 0.84. (orig.)

  20. "Super-Reducing" Photocatalysis: Consecutive Energy and Electron Transfers with Polycyclic Aromatic Hydrocarbons.

    Science.gov (United States)

    Brasholz, Malte

    2017-08-21

    Donation welcome: Recent developments in visible-light photocatalysis allow the utilization of increasingly negative reduction potentials. Successive energy and electron transfer with polycyclic aromatic hydrocarbons enables the catalytic formation of strongly reducing arene radical anions, classical stoichiometric reagents for one-electron reduction in organic synthesis. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Adsorption of hydrocarbons on modified nanoclays

    Energy Technology Data Exchange (ETDEWEB)

    Sharafimasooleh, M [Department of Materials Engineering, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Bazgir, S [Department of Engineering, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Tamizifar, M [Department of Metallurgy and Materials Engineering, University of Science and Technology, Tehran (Iran, Islamic Republic of); Nemati, A, E-mail: m.sharafimasooleh@gmail.com [Department of Materials Science and Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of)

    2011-04-15

    In this study organically modified nanoclay were prepared by exchanging of the cetyltrimethylammonium (CTAB), with inorganic/metal ions/cations in montmorillonite structure. To investigate the influence of the amount of modifier on basal spacing and subsequent removal efficiency of hydrocarbon, different amount of modifier was used. The modified and unmodified nanoclays characterized by XRD, CHN and FTIR techniques. The X-ray diffraction results showed that the interlayer spacing of CTAB-modified clays increased from 12 to 22A. The effectiveness of the sorbent materials for sorption of a range of products was investigated using crude oil, kerosene, gasoline and toluene. The process parameters such as sorbent dosage and contact time were reported. The results showed that the adsorption capacity was in the range of 2 to 8 gram per gram of adsorbent. Results also showed that adsorption capacity of the organoclay was clearly higher than of the unmodified clay. These results were confirmed by CHN analysis.

  2. Adsorption of hydrocarbons on modified nanoclays

    Science.gov (United States)

    Sharafimasooleh, M.; Bazgir, S.; Tamizifar, M.; Nemati, A.

    2011-04-01

    In this study organically modified nanoclay were prepared by exchanging of the cetyltrimethylammonium (CTAB), with inorganic/metal ions/cations in montmorillonite structure. To investigate the influence of the amount of modifier on basal spacing and subsequent removal efficiency of hydrocarbon, different amount of modifier was used. The modified and unmodified nanoclays characterized by XRD, CHN and FTIR techniques. The X-ray diffraction results showed that the interlayer spacing of CTAB-modified clays increased from 12 to 22Å. The effectiveness of the sorbent materials for sorption of a range of products was investigated using crude oil, kerosene, gasoline and toluene. The process parameters such as sorbent dosage and contact time were reported. The results showed that the adsorption capacity was in the range of 2 to 8 gram per gram of adsorbent. Results also showed that adsorption capacity of the organoclay was clearly higher than of the unmodified clay. These results were confirmed by CHN analysis.

  3. Catalytic co-pyrolysis of waste vegetable oil and high density polyethylene for hydrocarbon fuel production.

    Science.gov (United States)

    Wang, Yunpu; Dai, Leilei; Fan, Liangliang; Cao, Leipeng; Zhou, Yue; Zhao, Yunfeng; Liu, Yuhuan; Ruan, Roger

    2017-03-01

    In this study, a ZrO2-based polycrystalline ceramic foam catalyst was prepared and used in catalytic co-pyrolysis of waste vegetable oil and high density polyethylene (HDPE) for hydrocarbon fuel production. The effects of pyrolysis temperature, catalyst dosage, and HDPE to waste vegetable oil ratio on the product distribution and hydrocarbon fuel composition were examined. Experimental results indicate that the maximum hydrocarbon fuel yield of 63.1wt. % was obtained at 430°C, and the oxygenates were rarely detected in the hydrocarbon fuel. The hydrocarbon fuel yield increased when the catalyst was used. At the catalyst dosage of 15wt.%, the proportion of alkanes in the hydrocarbon fuel reached 97.85wt.%, which greatly simplified the fuel composition and improved the fuel quality. With the augment of HDPE to waste vegetable oil ratio, the hydrocarbon fuel yield monotonously increased. At the HDPE to waste vegetable oil ratio of 1:1, the maximum proportion (97.85wt.%) of alkanes was obtained. Moreover, the properties of hydrocarbon fuel were superior to biodiesel and 0# diesel due to higher calorific value, better low-temperature low fluidity, and lower density and viscosity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Enrichment of light hydrocarbon mixture

    Science.gov (United States)

    Yang, Dali [Los Alamos, NM; Devlin, David [Santa Fe, NM; Barbero, Robert S [Santa Cruz, NM; Carrera, Martin E [Naperville, IL; Colling, Craig W [Warrenville, IL

    2011-11-29

    Light hydrocarbon enrichment is accomplished using a vertically oriented distillation column having a plurality of vertically oriented, nonselective micro/mesoporous hollow fibers. Vapor having, for example, both propylene and propane is sent upward through the distillation column in between the hollow fibers. Vapor exits neat the top of the column and is condensed to form a liquid phase that is directed back downward through the lumen of the hollow fibers. As vapor continues to ascend and liquid continues to countercurrently descend, the liquid at the bottom of the column becomes enriched in a higher boiling point, light hydrocarbon (propane, for example) and the vapor at the top becomes enriched in a lower boiling point light hydrocarbon (propylene, for example). The hollow fiber becomes wetted with liquid during the process.

  5. Synthesis, identification, and acute toxicity of alpha-benzylphenethylamine and alpha-benzyl-N-methylphenethylamine. Contaminants in clandestine preparation of amphetamine and methamphetamine.

    Science.gov (United States)

    Noggle, F T; Clark, C R; Davenport, T W; Coker, S T

    1985-01-01

    Amphetamine samples obtained from clandestine laboratories often contain other by-product amines. The most common of these are the alpha-benzylphenethylamine derivatives. This article reports the independent synthesis of reference samples of these amines, spectrophotometric and chromatographic methods for their identification, as well as acute toxicological studies. The utility of the analytical methods is demonstrated by the analysis of several amphetamine samples containing these alpha-benzylphenethylamines.

  6. Total Petroleum Hydrocarbons (TPH): ToxFAQs

    Science.gov (United States)

    ... state: This map displays locations where Total Petroleum Hydrocarbons (TPH) is known to be present. On This ... get more information? ToxFAQs TM for Total Petroleum Hydrocarbons (TPH) ( Hidrocarburos Totales de Petróleo (TPH) ) August 1999 ...

  7. Tailored fischer-tropsch synthesis product distribution

    Science.gov (United States)

    Wang, Yong [Richland, WA; Cao, Chunshe [Kennewick, WA; Li, Xiaohong Shari [Richland, WA; Elliott, Douglas C [Richland, WA

    2012-06-19

    Novel methods of Fischer-Tropsch synthesis are described. It has been discovered that conducting the Fischer-Tropsch synthesis over a catalyst with a catalytically active surface layer of 35 microns or less results in a liquid hydrocarbon product with a high ratio of C.sub.5-C.sub.20:C.sub.20+. Descriptions of novel Fischer-Tropsch catalysts and reactors are also provided. Novel hydrocarbon compositions with a high ratio of C.sub.5-C.sub.20:C.sub.20+ are also described.

  8. Synthesis, characterization, and Fischer-Tropsch performance of cobalt/zinc aluminate nanocomposites via a facile and corrosion-free coprecipitation route

    Science.gov (United States)

    Liu, Zhenxin; Xing, Yu; Xue, Yingying; Wu, Depeng; Fang, Shaoming

    2015-02-01

    Literature about ZnAl2O4-supported cobalt Fischer-Tropsch synthesis (FTS) catalytic materials is sparse. A series of cobalt-containing nanocomposites, supported by nanosized ZnAl2O4 spinel (i.e., a complex oxide of about 6.4 nm) or alumina (i.e., a simple oxide of about 6.2 nm), were prepared via urea-gelation, coprecipitation, or impregnation methods followed by stepwise reduction. These materials were examined by XRD, TGA, nitrogen sorption, FESEM, and EDS. Effects of corrosion and pore size distributions on materials preparation were also investigated. The "coprecipitation/stepwise reduction" route is facile and suitable to prepare nanosized ZnAl2O4-supported Co0 nanocomposites. At similar CO conversions, the coprecipitated Co/ZnAl2O4 exhibits significantly lower C1 hydrocarbon distribution, slightly lower C5+ hydrocarbon distribution, significantly higher C2-C4 hydrocarbon distribution, and significantly higher olefin/paraffin ratio of C2-C4 than Co/γ-Al2O3.

  9. Hydrothermal oxidation-reduction methods for the preparation of pure and single crystalline alunites: synthesis and characterization of a new series of vanadium jarosites.

    Science.gov (United States)

    Grohol, Daniel; Nocera, Daniel G

    2002-03-20

    Three new redox-based, hydrothermal, synthetic methods have been developed for the preparation of a new series of jarosites, AV(3)(OH)(6)(SO(4))(2) (A = Na(+), K(+), Rb(+), Tl(+), and NH(4)(+)), in high purity and in single crystalline form. The V(3+) jarosites have been characterized by single-crystal X-ray and elemental analysis, and by infrared and electronic absorption spectroscopy. The synthetic methods employed here represent a new approach for the preparation of the jarosite class of compounds, which for the past several decades, have been notoriously difficult to prepare in pure form. To demonstrate the impact of our new synthetic techniques on the magnetic properties of jarosites, the V(3+) jarosites were also prepared according to the nonredox techniques used over the past 30 years. A comparative study of these samples and those prepared by our new synthetic methods reveals widely divergent magnetic properties, thus pointing to the importance of the new redox synthetic methods to future magnetism studies of jarosite compounds.

  10. Fast synthesis of the polycrystalline materials on the base of Zn 3 V2 MoO11 and Zn 2.5 VMoO8

    OpenAIRE

    Maya Markova-Velichkova; Reni Iordanova

    2009-01-01

    In our study we applied two different techniques for the preparation of Zn3V2MoO11 and Zn2.5VMoO8 polycrystalline materials - melt quenching method (up-bottom) and mechanochemical synthesis (bottom- up). These compounds belong to the family of materials with general formula M2.5VMoO8 (M=Zn, Mg, Mn, Co). They are potential candidates as catalysts in processes of selective oxidation of hydrocarbons. Until now, these two compounds were obtained by conventional solid state reaction. Using infrare...

  11. Compositions and methods for hydrocarbon functionalization

    Energy Technology Data Exchange (ETDEWEB)

    Gunnoe, Thomas Brent; Fortman, George; Boaz, Nicholas C.; Groves, John T.

    2017-03-28

    Embodiments of the present disclosure provide for methods of hydrocarbon functionalization, methods and systems for converting a hydrocarbon into a compound including at least one group ((e.g., hydroxyl group) (e.g., methane to methanol)), functionalized hydrocarbons, and the like.

  12. 33 CFR 157.166 - Hydrocarbon emissions.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Hydrocarbon emissions. 157.166... Crude Oil Washing (COW) System on Tank Vessels Cow Operations § 157.166 Hydrocarbon emissions. If the... ballasted in that port the hydrocarbon vapors in each tank are contained by a means under § 157.132. Note...

  13. Occurrence and growth potentials of hydrocarbon degrading ...

    African Journals Online (AJOL)

    ... the hydrocarbon occurred between the 8th and 14th day. It was therefore concluded that bacteria with ability to utilize hydrocarbons could be obtained from leaf surfaces. Such organisms could serve as seeds for bioaugmentation during remediation of polluted environments. Keywords: Phylloplane, bacteria, hydrocarbon, ...

  14. Extractive distillation of hydrocarbon mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Lee, F.M.; Brown, R.E.; Johnson, M.M.

    1991-07-16

    This patent describes a process for separating at least one aromatic hydrocarbon containing 6-12 carbon atoms per molecule from at least one close-boiling alkane by extractive distillation of a feed consisting essentially of the at least one aromatic hydrocarbon and the at least one alkane in the presence of a solvent consisting essentially of N-methyl-2-thiopyrrolidone, optionally in combination with at least one cosolvent selected from the group consisting of glycol compounds, sulfolane compounds and N-({beta}-mercaptoalkyl)-2-pyrrolidone compounds; wherein the extractive distillation process produces an overhead distillate product which contains a smaller volume percentage of the at least one alkane than the feed, and a bottoms product which contains the solvent and a larger volume percentage of the at least one aromatic hydrocarbon and a smaller volume percentage of the at least one alkane than the feed; and wherein the at least one aromatic hydrocarbon is separated from the solvent and recovered from the bottoms product. This patent also describes a process for separating at least one cycloalkane containing 5-10 carbon atoms per molecule from at least one close-boiling alkane by extracting distillation of a feed consisting essentially of the at least one cycloalkane and the at least one alkane in the presence of a solvent consisting essentially of N-methyl-2-thiopyrrolidone, optionally in combination with at least one cosolvent selected from the group consisting of glycol compounds, sulfone compounds and N-({beta}-mercaptoalkyl)-2-pyrrolidone compounds.

  15. Effective viscosity of confined hydrocarbons

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Samoilov, V.N.; Persson, B.N.J.

    2012-01-01

    We present molecular dynamics friction calculations for confined hydrocarbon films with molecular lengths from 20 to 1400 carbon atoms. We find that the logarithm of the effective viscosity ηeff for nanometer-thin films depends linearly on the logarithm of the shear rate: log ηeff=C-nlog γ̇, where...

  16. Steam Hydrocarbon Cracking and Reforming

    Science.gov (United States)

    Golombok, Michael

    2004-01-01

    The interactive methods of steam hydrocarbon reforming and cracking of the oil and chemical industries are scrutinized, with special focus on their resemblance and variations. The two methods are illustrations of equilibrium-controlled and kinetically-controlled processes, the analysis of which involves theories, which overlap and balance each…

  17. Deuterated interstellar polycyclic aromatic hydrocarbons

    NARCIS (Netherlands)

    Peeters, E; Allamandola, LJ; Bauschlicher, CW; Hudgins, DM; Sandford, SA; Tielens, AGGM

    2004-01-01

    We report infrared spectral evidence of deuterated interstellar polycyclic aromatic hydrocarbons (PAHs). Two bands are detected in the infrared emission from the ionization bar in Orion at 4.4 and 4.65 mum. The one at 4.65 mum is present at the 4.4 sigma level, while the one at 4.4 mum is more

  18. Ulva fasciata-mediated preparation of zinc oxide nanocrystalline for one-pot multicomponent synthesis of 6-amino-3-methyl-4-phenyl-2,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile

    Science.gov (United States)

    Cahyana, A. H.; Nurhayati; Utomo, B. S. B.; Ardiansah, B.

    2017-04-01

    ZnO has been successfully prepared by a simple co-precipitation method using sodium hydroxide, zinc acetate as precursor and Ulva fasciata polysaccharides as capping agent. Characterization using FTIR, XRD and SEM-EDS indicated the successful formation of ZnO nanocrystalline with crystallite size of 27.01 nm. In order to promote ZnO as a green catalyst, its application for one-pot multicomponent pyranopyrazole synthesis has been performed. Several reaction conditions have been investigated, and the highest yield (98%) was observed in the use of 10% mole of ZnO at room temperature for 90 min reaction time in aqueous medium to produce 6-amino-3-methyl-4-phenyl-2,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile.

  19. A new strategy for the preparation of peptide-targeted technetium and rhenium radiopharmaceuticals. The automated solid-phase synthesis, characterization, labeling, and screening of a peptide-ligand library targeted at the formyl peptide receptor.

    Science.gov (United States)

    Stephenson, Karin A; Banerjee, Sangeeta Ray; Sogbein, Oyebola O; Levadala, Murali K; McFarlane, Nicole; Boreham, Douglas R; Maresca, Kevin P; Babich, John W; Zubieta, Jon; Valliant, John F

    2005-01-01

    A new solid-phase synthetic methodology was developed that enables libraries of peptide-based Tc(I)/Re(I) radiopharmaceuticals to be prepared using a conventional automated peptide synthesizer. Through the use of a tridentate ligand derived from N-alpha-Fmoc-l-lysine, which we refer to as a single amino acid chelate (SAAC), a series of 12 novel bioconjugates [R-NH(CO)ZLF(SAAC)G, R = ethyl, isopropyl, n-propyl, tert-butyl, n-butyl, benzyl; Z = Met, Nle] that are designed to target the formyl peptide receptor (FPR) were prepared. Construction of the library was carried out in a multiwell format on an Advanced ChemTech 348 peptide synthesizer where multi-milligram quantities of each peptide were isolated in high purity without HPLC purification. After characterization, the library components were screened for their affinity for the FPR receptor using flow cytometry where the K(d) values were found to be in the low micromolar range (0.5-3.0 microM). Compound 5j was subsequently labeled with (99m)Tc(I) and the product isolated in high radiochemical yield using a simple Sep-Pak purification procedure. The retention time of the labeled compound matched that of the fully characterized Re-analogue which was prepared through the use of the same solid-phase synthesis methodology that was used to construct the library. The work reported here is a rare example of a method by which libraries of peptide-ligand conjugates and their rhenium complexes can be prepared.

  20. Synthesis of an Ionic Liquid and Its Application as Template for the Preparation of Mesoporous Material MCM-41: A Comprehensive Experiment for Undergraduate Students

    Science.gov (United States)

    Hu, Jun; Yin, Jinxiang; Lin, Tianshu; Li, Guangtao

    2012-01-01

    A new solvent-free microwave experiment to synthesize the ionic liquid 1-hexadecyl-3-methylimidazolium bromide (HDMIm-Br) in high yield is presented. The structure is confirmed by IR and [superscript 1]H NMR spectra. HDMIm-Br is then used to prepare an organic-inorganic mesoporous material MCM-41. The microscopic arrangements of mesoporous…

  1. Synthesis and characterization of alumina-supported vanadium oxide catalysts prepared by the molecular designed dispersion of VO(acac)2 complexes

    NARCIS (Netherlands)

    Weckhuysen, B.M.; Baltes, M.; Voort, P. van der; Ramachandra Rao, R.; Catana, Gabriela; Schoonheydt, R.A.; Vansant, E.F.

    2000-01-01

    Alumina-supported vanadium oxide catalysts have been prepared by the molecular designed dispersion method, using the vanadyl acetylacetonate complex (VO(acac)2). The complex has been adsorbed on the support from solution, followed by thermal conversion into the corresponding supported vanadium oxide

  2. Fundamentals of Melt infiltration for the Preparation of Supported Metal Catalysts.The Case of Co/SiO2 Fischer-Tropsch Synthesis

    NARCIS (Netherlands)

    Eggenhuisen, T.M.|info:eu-repo/dai/nl/313959498; den Breejen, J.P.|info:eu-repo/dai/nl/304837318; Verdoes, D.; de Jongh, P.E.|info:eu-repo/dai/nl/186125372; de Jong, K.P.|info:eu-repo/dai/nl/06885580X

    2013-01-01

    We explored melt infiltration of mesoporous silica supports to prepare supported metal catalysts with high loadings and controllable particle sizes. Melting of Co(NO3)2 ·6H2O in the presence of silica supports was studied in situ with differential scanning calorimetry. The melting point depression

  3. Synthesis and Migratory-Insertion Reactivity of CpMo(CO)[subscript3](CH[subscript3]): Small-Scale Organometallic Preparations Utilizing Modern Glovebox Techniques

    Science.gov (United States)

    Whited, Matthew T.; Hofmeister, Gretchen E.

    2014-01-01

    Experiments are described for the reliable small-scale glovebox preparation of CpMo(CO)[subscript 3](CH[subscript 3]) and acetyl derivatives thereof through phosphine-induced migratory insertion. The robust syntheses introduce students to a variety of organometallic reaction mechanisms and glovebox techniques, and they are easily carried out…

  4. Redesign of a Grignard-Based Active Pharmaceutical Ingredient (API) Batch Synthesis to a Flow Process for the Preparation of Melitracen HCl

    DEFF Research Database (Denmark)

    Pedersen, Michael J.; Skovby, Tommy; Mealy, Michael J.

    2018-01-01

    A Grignard-based batch process, for the preparation of Melitracen HCl, has been redesigned to fit a continuous reactor system. The Grignard addition is carried out at room temperature, with subsequent hydrolysis of the magnesium alkoxide intermediate followed by dehydration of the resulting alcoh...

  5. A New Iterative Approach for the Synthesis of Oligo(phenyleneethynediyl) Derivatives and Its Application for the Preparation of Fullerene-Oligo(phenyleneethynediyl) Conjugates as Active Photovoltaic Materials

    NARCIS (Netherlands)

    Nierengarten, Jean-François; Gu, Tao; Hadziioannou, Georges; Tsamouras, Dimitris; Krasnikov, Victor

    2004-01-01

    Disymmetrically substituted oligo(phenyleneethynediyl) (OPE) derivatives were prepared from 2,5-bis(octyloxy)-4-[(triisopropylsilyl)ethynyl]benzaldehyde (5) by an iterative approach using the following reaction sequence: i) Corey-Fuchs dibromoolefination, ii) treatment with an excess of lithium

  6. Synthesis of robust and high-performance aquaporin-based biomimetic membranes by interfacial polymerization-membrane preparation and RO performance characterization

    DEFF Research Database (Denmark)

    Zhao, Yang; Qiu, Changquan; Li, Xuesong

    2012-01-01

    Aquaporins are water channel proteins with excellent water permeability and solute rejection, which makes them promising for preparing high-performance biomimetic membranes. Despite the growing interest in aquaporin-based biomimetic membranes (ABMs), it is challenging to produce robust and defect...

  7. Application of 2-cyanoethyl n,n,n′,n′-tetraisopropylphosphorodiamidite for in situ preparation of deoxyribonucleoside phosphoramidites and their use in polymer-supported synthesis of oligodeoxyribonucleotides

    DEFF Research Database (Denmark)

    Nielsen, John; Taagaard, Michael; Marugg, John E.

    1986-01-01

    Deoxyribonucleoside phosphoramidites are prepared in situ from 5′-O,N-protected deoxyribonucleosides and 2-cyanoethyl N,N,N′,N′-tetraisopropylphosphorodiamidite with tetrazole as catalyst, and the solutions applied directly on an automatic solid-phase DNA synthesizer. Using LCAA-CPG support...

  8. Ethanol synthesis and water gas shift over bifunctional sulfide catalysts. Final technical progress report, September 12, 1991--December 11, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Klier, K.; Herman, R.G.; Deemer, M.; Richards-Babb, M.; Carr, T.

    1995-07-01

    The objective of this research was to investigate sulfur-resistant catalysts for the conversion of synthesis gas having H{sub 2}/CO {le} 1 into C{sub 1}--C{sub 4} alcohols, especially ethanol, by a highly selective and efficient pathway, while also promoting the water gas shift reaction (WGSR). The catalysts chosen are bifunctional, base-hydrogenation, sulfur-tolerant transition metal sulfides with heavy alkali, e.g. Cs{sup +}, promoter dispersed on their surfaces. The modes of activation of H{sub 2} and CO on MoS{sub 2} and alkali-doped MoS{sub 2} were considered, and computational analyses of the thermodynamic stability of transition metal sulfides and of the electronic structure of these sulfide catalysts were carried out. In the preparation of the cesium-promoted MoS{sub 2} catalysts, a variety of preparation methods using CsOOCH were examined. In all cases, doping with CsOOCH led to a lost of surface area. The undoped molybdenum disulfide catalyst only produced hydrocarbons. Cs-doped MoS{sub 2} catalysts all produced linear alcohols, along with smaller amounts of hydrocarbons. With a 20 wt% CsOOCH/MoS{sub 2} catalyst, temperature, pressure, and flow rate dependences of the synthesis reactions were investigated in the presence and absence of H{sub 2}S in the H{sub 2}/CO = 1/1 synthesis gas during short term testing experiments. It was shown that with a carefully prepared 10 wt% CsOOCH/MoS{sub 2} catalyst, reproducible and high alcohol synthesis activity could be obtained. For example, at 295 C with H{sub 2}/CO = 1 synthesis gas at 8.3 MPa and with GHSV = 7,760 l/kg cat/hr, the total alcohol space time yield was ca 300 g/kg cat/hr (accompanied with a hydrocarbon space time yield of ca 60 g/kg cat/hr). Over a testing period of ca 130 hr, no net deactivation of the catalyst was observed. 90 refs., 82 figs., 14 tabs.

  9. Effect of process parameters on the phase formation, particle size and magnetic properties of MnBi nanoparticles prepared by mechanochemical synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Rama Rao, N.V., E-mail: nvrrao@udel.edu; Hadjipanayis, G.C.

    2014-12-15

    Highlights: • Process parameters plays major role in controlling particle size, phase formation and magnetic properties. • Increase of the dispersant amount helps to decrease the particle size and make separated particles. • MnBi phase formation increases as the heat-treatment temperature increases. • Hc and Ms values are obtained in the range of 11–18.2 kOe and 13–32 emu/g, respectively. • Optimum magnetic properties with smaller particle size were obtained with 30 wt.% of CaO and at lower heat-treatment temperature. - Abstract: Nanoparticles of MnBi are obtained from Bi{sub 2}O{sub 3} and Mn by mechanochemical synthesis. The effect of excess dispersant (CaO) in mechanochemical synthesis and the temperature of subsequent thermal treatment on phase formation, particle size and magnetic properties of MnBi nanoparticles is investigated by means of X-ray diffraction analysis, scanning electron microscopy and magnetometry. With increase of excess dispersant, the average particle size decreases and the particles are observed to be more separated. Saturation magnetization (M{sub s}) was found to decrease with increase of excess dispersant, while the coercivity (H{sub c}) increases with the increase of dispersant up to 40 wt.% and thereafter it decreases. The formation of MnBi phase increases as the heat-treatment temperature is increased; however, the average particle size increases from nano to micrometer (200 nm to 2 μm)

  10. Direct synthesis and morphological characterization of gold-dendrimer nanocomposites prepared using PAMAM succinamic acid dendrimers: preliminary study of the calcification potential.

    Science.gov (United States)

    Vasile, E; Serafim, A; Petre, D; Giol, D; Dubruel, P; Iovu, H; Stancu, I C

    2014-01-01

    Gold-dendrimer nanocomposites were obtained for the first time by a simple colloidal approach based on the use of polyamidoamine dendrimers with succinamic acid terminal groups and dodecanediamine core. Spherical and highly crystalline nanoparticles with dimensions between 3 nm and 60 nm, and size-polydispersity depending on the synthesis conditions, have been generated. The influence of the stoichiometric ratio and the structural and architectural features of the dendrimers on the properties of the nanocomposites has been described. The self-assembling behaviour of these materials produces gold-dendrimer nanostructured porous networks with variable density, porosity, and composition. The investigations of the reaction systems, by TEM, at two postsynthesis moments, allowed to preliminary establish the control over the properties of the nanocomposite products. Furthermore, this study allowed better understanding of the mechanism of nanocomposite generation. Impressively, in the early stages of the synthesis, the organization of gold inside the dendrimer molecules has been evidenced by micrographs. Growth and ripening mechanisms further lead to nanoparticles with typical characteristics. The potential of such nanocomposite particles to induce calcification when coating a polymer substrate was also investigated.

  11. One-pot solvothermal synthesis of a well-ordered layered sodium aluminoalcoholate complex: a useful precursor for the preparation of porous Al2O3 particles

    Energy Technology Data Exchange (ETDEWEB)

    Li, XS; Michaelis, VK; Ong, TC; Smith, SJ; McKay, I; Muller, P; Griffin, RG; Wang, EN

    2014-01-01

    One-pot solvothermal synthesis of a robust tetranuclear sodium hexakis(glycolato)tris(methanolato)aluminate complex Na-3[Al-4(OCH3)(3)(OCH2CH2O)(6)] via a modified yet rigorous base-catalyzed transesterification mechanism is presented here. Single crystal X-ray diffraction (SCXRD) studies indicate that this unique Al complex contains three pentacoordinate Al3+ ions, each bound to two bidentate ethylene glycolate chelators and one monodentate methanolate ligand. The remaining fourth Al3+ ion is octahedrally coordinated to one oxygen atom from each of the six surrounding glycolate chelators, effectively stitching the three pentacoordinate Al moieties together into a novel tetranuclear Al complex. This aluminate complex is periodically self-assembled into well-ordered layers normal to the [110] axis with the intra-/inter-layer bonding involving extensive ionic bonds from the three charge-counterbalancing Na+ cations rather than the more typical hydrogen bonding interactions as a result of fewer free hydroxyl groups present in its structure. It can also serve as a valuable precursor toward the facile synthesis of high-surface-area alumina powders using a very efficient rapid pyrolysis technique.

  12. Direct Synthesis and Morphological Characterization of Gold-Dendrimer Nanocomposites Prepared Using PAMAM Succinamic Acid Dendrimers: Preliminary Study of the Calcification Potential

    Directory of Open Access Journals (Sweden)

    E. Vasile

    2014-01-01

    Full Text Available Gold-dendrimer nanocomposites were obtained for the first time by a simple colloidal approach based on the use of polyamidoamine dendrimers with succinamic acid terminal groups and dodecanediamine core. Spherical and highly crystalline nanoparticles with dimensions between 3 nm and 60 nm, and size-polydispersity depending on the synthesis conditions, have been generated. The influence of the stoichiometric ratio and the structural and architectural features of the dendrimers on the properties of the nanocomposites has been described. The self-assembling behaviour of these materials produces gold-dendrimer nanostructured porous networks with variable density, porosity, and composition. The investigations of the reaction systems, by TEM, at two postsynthesis moments, allowed to preliminary establish the control over the properties of the nanocomposite products. Furthermore, this study allowed better understanding of the mechanism of nanocomposite generation. Impressively, in the early stages of the synthesis, the organization of gold inside the dendrimer molecules has been evidenced by micrographs. Growth and ripening mechanisms further lead to nanoparticles with typical characteristics. The potential of such nanocomposite particles to induce calcification when coating a polymer substrate was also investigated.

  13. Synthesis and preliminary bioevaluation of 99mTc(CO)3-17α-triazolylandrost-4-ene-3-one derivative prepared via click chemistry route.

    Science.gov (United States)

    Dhyani, Manish V; Satpati, Drishty; Korde, Aruna; Banerjee, Sharmila

    2011-10-01

    Azolyl steroids are known to manifest antiprostate cancer and antiandrogenic activities. These azolyl steroids have been shown to express affinity toward androgen receptors (ARs) overexpressed on LNCaP (human prostate adenocarcinoma) cell line. Hence, suitably derivatized azolyl steroids can be envisaged as potential vectors for targeting overexpression of ARs in prostate cancer. In the present study, testosterone has been derivatized to 17α-azidoandrost-4-ene-3-one using microwave-mediated azidation of the mesylate. Subsequently, a facile one-pot Cu(I)-catalyzed Click reaction was carried out to synthesize (99m)Tc(CO)(3)-labeled 17α-triazolylandrost-4-ene-3-one, which was characterized by HPLC. The chemical characterization of (99m)Tc(CO)(3)-17α-triazolylandrost-4-ene-3-one was carried out by preparing its corresponding rhenium complex using [NEt(4)](2)[Re(CO)(3)Br(3)] precursor. The radiolabeled complex could be prepared in >95% radiochemical yield as determined by HPLC. In vitro studies of (99m)Tc(CO)(3)-17α-triazolylandrost-4-ene-3-one complex in LNCaP cell lines overexpressing ARs showed binding of 4.95%±1.2%, with inhibition of 8%±0.9%. In vivo biodistribution studies in male Wistar rats have shown uptake in the prostate to the extent of 0.48%±0.19% injected dose/g at 1 hpi and retention therein till 3 hpi. The present study demonstrates a novel and facile one-pot reaction for preparation of (99m)Tc-labeled 17α-triazolylandrost-4-ene-3-one complex using Click chemistry. The corresponding Re-analog has been prepared for purpose of comparative characterization with the (99m)Tc-labeled complex. The radiosynthetic strategy described in this article can be further extended toward preparation of radiolabeled complexes of other triazolyl steroidal derivatives.

  14. Biodegradation of petroleum hydrocarbons in hypersaline environments

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Martins

    2012-09-01

    Full Text Available Literature on hydrocarbon degradation in extreme hypersaline media presents studies that point to a negative effect of salinity increase on hydrocarbonoclastic activity, while several others report an opposite tendency. Based on information available in the literature, we present a discussion on the reasons that justify these contrary results. Despite the fact that microbial ability to metabolize hydrocarbons is found in extreme hypersaline media, indeed some factors are critical for the occurrence of hydrocarbon degradation in such environments. How these factors affect hydrocarbon degradation and their implications for the assessment of hydrocarbon biodegradation in hypersaline environments are presented in this review.

  15. Preparation and characterization of new zeolite membranes. Application to gaseous separation; Preparation et caracterisation de nouvelles membranes de zeolithe application a la separation gazeuse

    Energy Technology Data Exchange (ETDEWEB)

    Anstett, M.

    1996-11-25

    Zeolites are interesting for the preparation of inorganic membranes which could be used for the continuous separation of gas and liquids by gas permeation and pervaporation. Zeolites membranes are obtained by hydrothermal synthesis and are characterized by XRD, SEM, TDA, IR, chemical analysis, EPMA, NMR, MAS NMR and gas permeation. After some tests of preparation of zeolite CHA and MFI self supporting membranes, the work is turned towards the preparation of zeolite MFI membranes supported by porous disks or {alpha} alumina, glass and tubes of carbon covered with a thin layer or zirconium dioxide. It is shown that the characteristics of the support (reactivity, pores dimensions, ...) strongly influence the quality of the prepared membrane. Two originals preparation processes are finalized. For the alumina disks, a gel precursor of zeolite is firs formed at the surface of the support by immersing successively that support in two non miscible liquids before the crystallisation. The gel is then converted into the zeolite by contact with water vapor. The zeolite layer obtained is localized at the surface of the support and present not only at the outside but also at the inside of the support. The characteristics of the zeolite layer can be controlled and the method can be adapted to various porous supports. The membrane obtained is interesting for hydrocarbons separations, for example the separation of methane and isobutane. In the case of Vycor glass disks, the reactivity of the support is first enhanced by contact with saturated water vapour. The temperature of the synthesis is then chosen relatively low in order to limit the attack of the support. With that method, a basic solution can be used without degradation of the support.The basicity leads to the formation of little crystals whose assembling is compact and homogeneous. The membrane obtained is interesting for example for the separation of normal butane and isobutane. (author) 71 refs.

  16. Photoacoustic spectroscopic studies of polycyclic aromatic hydrocarbons

    Science.gov (United States)

    Zaidi, Zahid H.; Kumar, Pardeep; Garg, R. K.

    1999-02-01

    Because of their involvement in environmental pollutants, in carcinogenic activity, plastics, pharmaceuticals, synthesis of some laser dyes and presence in interstellar space etc., Polycyclic aromatic hydrocarbons (PAHs) are important. As their structure and properties can be varied systematically, they form a beautiful class of molecules for experimental and quantum chemical investigations. These molecules are being studied for last several years by using conventional spectroscopy. In recent years, Photoacoustic (PA) spectroscopy has emerged as a new non-destructive technique with unique capability and sensitivity. The PA effect is the process of generation of acoustic waves in a sample resulting from the absorption of photons. This technique not only reveals non- radiative transitions but also provides information about forbidden singlet-triplet transitions which are not observed normally by the conventional spectroscopy. The present paper deals with the spectroscopic studies of some PAH molecules by PA spectroscopy in the region 250 - 400 nm. The CNDO/S-CI method is used to calculate the electronic transitions with the optimized geometries. A good agreement is found between the experimental and calculated results.

  17. Tolerance of Antarctic soil fungi to hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Kevin A.; Bridge, Paul; Clark, Melody S. [British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 0ET (United Kingdom)

    2007-01-01

    Little is known about the effects of hydrocarbons and fuel oil on Antarctic filamentous fungi in the terrestrial Antarctic environment. Growth of fungi and bacteria from soils around Rothera Research Station (Adelaide Island, Antarctic Peninsula) was assessed in the presence of ten separate aromatic and aliphatic hydrocarbons [marine gas oil (MGO), dodecane, hexadecane, benzoic acid, p-hydroxybenzoic acid, toluene, phenol, biphenyl, naphthalene and m- and p-xylenes with ethylbenzene]. Aromatic hydrocarbons inhibited soil microbial growth more than aliphatic hydrocarbons. Soil microorganisms from a moss patch, where little previous impact or hydrocarbon contamination had occurred, were less tolerant of hydrocarbons than those from high impact sites. Fungal growth rates of Mollisia sp., Penicillium commune, Mortierella sp., Trichoderma koningii, Trichoderma sp. and Phoma herbarum were assessed in the presence of hydrocarbons. Generally, aromatic hydrocarbons inhibited or stopped hyphal extension, though growth rates increased with some aliphatic hydrocarbons. Hyphal dry weight measurements suggested that Mortierella sp. may be able to use dodecane as sole carbon and energy source. Hydrocarbon-degrading Antarctic fungi may have use in future hydrocarbon spill bioremediation. (author)

  18. Thermodynamic models to predict gas-liquid solubilities in the methanol synthesis, the methanol-higher alcohol synthesis, and the Fischer-Tropsch synthesis via gas-slurry processes

    NARCIS (Netherlands)

    Breman, B.B; Beenackers, A.A C M

    1996-01-01

    Various thermodynamic models were tested concerning their applicability to predict gas-liquid solubilities, relevant for synthesis gas conversion to methanol, higher alcohols, and hydrocarbons via gas-slurry processes. Without any parameter optimization the group contribution equation of state

  19. Fully automated preparation of [{sup 11}C]choline and [{sup 18}F]fluoromethylcholine using TracerLab synthesis modules and facilitated quality control using analytical HPLC

    Energy Technology Data Exchange (ETDEWEB)

    Shao Xia; Hockley, Brian G.; Hoareau, Raphael; Schnau, Paul L. [Department of Radiology, University of Michigan, Ann Arbor, MI 48109 (United States); Scott, Peter J.H., E-mail: pjhscott@umich.ed [Department of Radiology, University of Michigan, Ann Arbor, MI 48109 (United States)

    2011-02-15

    Modifications of a GE TracerLab FX{sub C-Pro}, which can be implemented for solid-phase [{sup 11}C]methylation are described. The simplified procedure for synthesis of [{sup 11}C]choline uses a single Sep-Pak CM-Light cation-exchange cartridge for both solid-supported reaction and purification. Compared with the commonly used two Sep-Pak method, the low back-pressure of this Sep-Pak enables efficient and reliable production of [{sup 11}C]choline using a TracerLab FX{sub C-Pro} without requirement for any gas pressure adjustment. Typical radiochemical yields (RCY) are >60%, radiochemical purity (RCP) is 99.9% and levels of residual precursor in the final product, which may inhibit the uptake of [{sup 11}C]choline, are reduced to 1 {mu}g/mL. Similarly, modification of a GE TracerLab FX{sub FN} is reported which enables gas-phase production of [{sup 18}F]fluoromethylcholine, suitable for pre-clinical use, (in 4-6% RCY and >99.7% RCP) using a related Sep-Pak method. These modifications can be utilized for solid-phase [{sup 11}C]methylation and [{sup 18}F]fluoromethylation of other radiotracers, and allow straightforward switching to other module configurations for solution-phase radiochemistry or loop chemistry. In addition, we report a convenient HPLC ion chromatography method, which can monitor residual precursor and the radiochemical purity of product at the same time, providing highly efficient quality control for routine clinical application. The reported HPLC method is appropriate for analysis of doses of both [{sup 11}C]choline and [{sup 18}F]fluoromethylcholine, and eliminates the need for a GC method to determine residual precursor levels. -- Graphical abstract: Simplified procedures for the automated synthesis of [{sup 11}C]choline and [{sup 18}F]fluoromethylcholine using TracerLab FX{sub C-Pro} and TracerLab FX{sub FN} synthesis modules are presented. In addition, we report a convenient HPLC ion chromatography method, which can monitor residual precursor and

  20. A rapid column technique for trapping and collecting of volatile fungal hydrocarbons and hydrocarbon derivatives.

    Science.gov (United States)

    Booth, Eric; Strobel, Gary; Knighton, Berk; Sears, Joe; Geary, Brad; Avci, Recep

    2011-10-01

    A custom-made stainless steel column was designed to contain various materials that would trap the hydrocarbons and hydrocarbon derivatives during the processes of fungal fermentation ultimately yielding preparative amounts of volatile organic substances (VOCs). Trapping materials tested in the column were Carbotrap materials A and B (Supelco) as well as bentonite-shale from the oil bearing areas of Eastern Montana, the former allowed for the effective and efficient trapping of VOCs from purged cultures of Hypoxylon sp. Trapping efficiencies of various materials were measured by both gravimetric as well as proton transfer reaction mass spectroscopy with the Carbotraps A and B being 99% efficient when tested with known amounts of 1,8-cineole. Trapped fungal VOCs could effectively be removed and recovered via controlled heating of the stainless steel column followed by passage of the gases through a liquid nitrogen trap at a recovery rate of ca 65-70%. This method provides for the recovery of mg quantities of compounds normally present in the gas phase that may be needed for spectroscopy, bioassays and further separation and analysis and may have wide applicability for many other biological systems involving VOCs. Other available Carbotraps could be used for other applications. © Springer Science+Business Media B.V. 2011

  1. Laboratory analytical methods for the determination of the hydrocarbon status of soils (a review)

    Science.gov (United States)

    Pikovskii, Yu. I.; Korotkov, L. A.; Smirnova, M. A.; Kovach, R. G.

    2017-10-01

    Laboratory analytical methods suitable for the determination of the hydrocarbon status of soils (a specific soil characteristic involving information on the total content and qualitative features of soluble (bitumoid) carbonaceous substances and individual hydrocarbons (polycyclic aromatic hydrocarbons, alkanes, etc.) in bitumoid, as well as the composition and content of hydrocarbon gases) have been considered. Among different physicochemical methods of study, attention is focused on the methods suitable for the wide use. Luminescence-bituminological analysis, low-temperature spectrofluorimetry (Shpolskii spectroscopy), infrared (IR) spectroscopy, gas chromatography, chromatography-mass spectrometry, and some other methods have been characterized, as well as sample preparation features. Advantages and limitations of each of these methods are described; their efficiency, instrumental complexity, analysis duration, and accuracy are assessed.

  2. Synthesis of Polyvinyl Pirrolidone (PVC /Κ-Carrageenan Hydrogel Prepared by Gamma Radiation Processing As a Function of Dose and PVP Concentration

    Directory of Open Access Journals (Sweden)

    Erizal Erizal

    2013-05-01

    Full Text Available The aim of this research is to prepare a biomaterial to be used in health care. A series of hydrogels based on polyvinyl pyrrolidone (PVP/κ-Carrageenan (KC has been prepared by radiation technique. PVP (5-15% were mixed with ΚC (2% and irradiated by gamma rays at the doses from 25 kGy to 35 kGy (dose rate 7 kGy/h at room temperature. The chemical change of hydrogels was characterized using Fourier Transform infra Red (FTIR. Gel fraction, water absorption and water evaporation were determined gravimetrically. Tensile strength and elongation at break was measured using Instron meter. It was found that with the increase irradiation dose and PVP concentration, the gel fraction and tensile strength of hydrogels increase. In contrast the elongation at break and water absorption of hydrogels decrease. The hydrogel of PVP/KC hydrogel produced by gamma radiation can be considered for wound dressings.

  3. Atom transfer as a preparative tool in coordination chemistry. Synthesis and characterization of Cr(V) nitrido complexes of bidentate ligands

    DEFF Research Database (Denmark)

    Birk, Torben; Bendix, Jesper

    2003-01-01

    The transfer of a terminal nitrido ligand from MnV(N)(salen) to Cr(III) complexes is explored as a new preparative route to CrV nitrido complexes. Reaction of MnV(N)(salen) with labile CrCl3(THF)3 in acetonitrile solution precipitate [Mn(Cl)(salen)]·(CH3CN) and yields a solution containing a mixt...

  4. Synthesis and characterization of novel functional electrosterically stabilized colloidal particles prepared by emulsion polymerization using a strongly ionized amphiphilic diblock copolymer

    OpenAIRE

    Priti S. Mohanty; Dietsch, Hervé; Rubatat, Laurent; Stradner, Anna; Matsumoto, K.; Matsuoka, H; Schurtenberger, Peter

    2009-01-01

    Amphiphilic diblock copolymers such as poly(styrene)-block-poly(styrene sulfonate) (PS-b-PSS) (Matsuoka, H.; Maeda, S.; Kaewsaiha, P.; Matsumoto, K. Langmuir 2004, 20, 7412), belong to a class of new polymeric surfactants that ionize strongly in aqueous media. We investigated their self-assembly behavior in aqueous solutions and used them as an emulsifier to prepare electrosterically stabilized colloidal particles of different diameters between 70 to 400 nm. We determined the size, size polyd...

  5. Reaction of 1,2-orthoesters with HF-pyridine: a method for the preparation of partly unprotected glycosyl fluorides and their use in saccharide synthesis.

    Science.gov (United States)

    López, J Cristóbal; Ventura, Juan; Uriel, Clara; Gómez, Ana M; Fraser-Reid, Bert

    2009-09-17

    Glycosyl fluorides can be prepared in an efficient manner by treatment of pyranose- or furanose-derived 1,2-orthoesters, with hydrogen fluoride pyridine (HF-py). The method is compatible with the presence of a variety of protecting groups, including tert-butyldiphenyl silyl ethers, and can be applied to sugar derivatives with free hydroxyl groups, thus avoiding the need for the protection-deprotection steps.

  6. Magnetic and optical properties of (GaMn)N nanocrystalline powders prepared by the aerosol-assisted vapour phase synthesis and anaerobic imide route methods

    Energy Technology Data Exchange (ETDEWEB)

    Gosk, J B [Institute of Experimental Physics, Warsaw University, Hoza 69, 00-681 Warsaw (Poland); Drygas, M [Faculty of Fuels and Energy, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Cracow (Poland); Janik, J F [Faculty of Fuels and Energy, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Cracow (Poland); Palczewska, M [Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warsaw (Poland); Paine, R T [Department of Chemistry, University of New Mexico, Albuquerque, NM 87131 (United States); Twardowski, A [Institute of Experimental Physics, Warsaw University, Hoza 69, 00-681 Warsaw (Poland)

    2006-09-07

    Herein, we report a study on magnetic and optical properties of hexagonal (GaMn)N nanocrystalline powders obtained by two methods: aerosol-assisted vapour phase synthesis and anaerobic imide route. Measurements of the magnetization as a function of temperature and magnetic field for the powders show a typical paramagnetic behaviour. In addition, antiferromagnetic contribution originating from a residual MnO by-product and a small ferromagnetic contribution are observed. Magnetization measured as the function of magnetic field shows a smaller saturation effect than expected for non-interacting Mn-ions. Electron paramagnetic resonance (EPR) measurements reveal a single, structureless resonance line with a g-factor equal to 2.008{+-}0.003 indicating a presence of Mn{sup 2+}-centres in the samples. Both magnetic and EPR measurements suggest weak AF interactions between Mn-ions incorporated in (GaMn)N.

  7. Ni nanoparticles prepared by simple chemical method for the synthesis of Ni/NiO-multi-layered graphene by chemical vapor deposition

    Science.gov (United States)

    Ali, Mokhtar; Remalli, Nagarjuna; Gedela, Venkataramana; Padya, Balaji; Jain, Pawan Kumar; Al-Fatesh, Ahmed; Rana, Usman Ali; Srikanth, Vadali V. S. S.

    2017-02-01

    A new chemical method was used to obtain a high yield of nickel nanoparticles (Ni-NPs). The effect of solvent (distilled water, ethylene glycol, and ethanol) and surfactant (oleic acid and polyvinyl pyrrolidinone) on the morphology and crystallinity of the synthesized Ni-NPs has been investigated. The experimental results revealed that among the solvents mentioned above, ethanol gives the best results in terms of complete reduction, controlled morphology and size distribution of Ni-NPs. The surfactants played an important role in impeding the agglomeration and surface oxidation of Ni-NPs. The surfactants also affected the morphology of the Ni-NPs. The synthesized Ni-NPs are found to be quite stable in air. The best of the synthesized Ni-NPs were effectively used as catalysts for the synthesis of Ni/NiO-multi-layered graphene using catalytic chemical vapor deposition technique.

  8. Synthesis and characterization of polypropylene/graphite nano composite preparation for in situ polymerization; Sintese e caracterizacao de nanocompositos polipropileno/grafite obtidos pela polimerizacao in situ

    Energy Technology Data Exchange (ETDEWEB)

    Montagna, L.S.; Fim, F. de C.; Galland, G.B. [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Inst. de Quimica; Basso, N.R.S., E-mail: nrbass@pucrs.b [Pontificia Universidade Catolica do Rio Grande do Sul (PUC-RS), Porto Alegre, RS (Brazil)

    2010-07-01

    This paper presents the synthesis of polypropylene/graphite nanocomposites through in situ polymerization, using the metallocene catalyst C{sub 20}H{sub 16}Cl{sub 2}Zr (dichloro(rac-ethylenebis(indenyl))zircon(IV)). The graphite nanosheets in nano dimensions were added to the polymer matrix in percentages of 0.6;1.0;4.2;4.8 and 6.0% (w/w). The TEM images indicated that the thickness of graphite nanosheets ranged from 4 to 60 nm and by means of XRD analysis it was observed that the physical and chemical treatment did not destroyed the graphite layers. The presence of nanosheets did not decrease the catalytic activity of the nanocomposites. TEM images and XRD analysis of nanocomposites showed a good dispersion of the graphite nanosheets in the polypropylene matrix. (author)

  9. Preparation and Characterization of a Molybdenum(VI Schiff Base Complex as Magnetic Nanocatalyst for Synthesis of 2-Amino-4H-benzo[h]chromenes

    Directory of Open Access Journals (Sweden)

    Naghmeh Divsalar

    2016-10-01

    Full Text Available A new recoverable molybdenum nanocatalyst was prepared by immobilization  of a Schiff base ligand on the surface of silica coated magnetite nanoparticles (Fe3O4@SiO2 through condensation reaction between 3-aminopropyl triethoxysilane and 2-hydroxy1-naphthaldehyde and succeeding reaction with dioxomolybdenum(VI acetylacetonate (MoO2(acac2. The synthesized catalyst was characterized by inductively coupled plasma, thermogravimetric analysis, scanning electron microscopy, vibrating sample magnetometry, Energy-dispersive X-ray, Fourier transform infrared and X-raydiffraction spectroscopy. Catalytic performance of the synthesized nanocatalyst was investigated for the preparation of 2-amino-4H-benzo[h]chromenes. The compounds were prepared high yield through one-pot, three-component reaction of 1-naphthol, various of aldehydes and malonitrile in the presence of nanocatalyst, Fe3O4@SiO2@Mo-Schiff base, under solvent-free conditions. The benefits of this protocol are short reaction time, simple work-up procedure, high yields and use of the concept of green chemistry. The magnetic nanocatalyst could be separated easily from the reaction media using an external magnetic field and reused in subsequent catalytic runs without significant deterioration of its activity.

  10. Sun light mediated synthesis of gold nanoparticles as carrier for 6-mercaptopurine: Preparation, characterization and toxicity studies in zebrafish embryo model

    Energy Technology Data Exchange (ETDEWEB)

    Ganeshkumar, Moorthy [Department of Biochemistry, Central Leather Research Institute, Council of Scientific and Industrial Research, Chennai 600020 (India); Sastry, Thotapalli Parvathaleswara [Bioproducts Laboratory, Central Leather Research Institute, Chennai 600020 (India); Sathish Kumar, Muniram [Department of Pharmaceutics, Anna University, Trichy, Tamilnadu (India); Dinesh, Murugan Girija [Thanthai Hansroever College, Perambalur, Tamilnadu (India); Kannappan, Sudalyandi [Central Institute of Brackish Water Aquaculture, Chennai 600028 (India); Suguna, Lonchin, E-mail: slonchin@yahoo.co.uk [Department of Biochemistry, Central Leather Research Institute, Council of Scientific and Industrial Research, Chennai 600020 (India)

    2012-09-15

    Highlights: ► Gold nanoparticles prepared using eco-friendly method with good in vitro stability. ► Can be used as drug delivery system. ► Did not show any toxicity in zebrafish embryo. ► More toxic to cancer cells when compared to N-Au-Mp and Mp. -- Abstract: The objective of this study is to synthesize green chemistry based gold nanoparticles by sun light irradiation method. The prepared gold nanoparticles (AuNPs) were modified using folic acid and then coupled with 6-mercaptopurine. These modified nanoparticles were used as a tool for targeted drug delivery to treat laryngeal cancer. In the present study, novel bionanocomposites containing nutrient agar coated gold nano particles (N-AuNPs) coupled with 6-mercaptopurine (drug) (N-AuNPs-Mp), folic acid (ligand) (N-AuNPs-Mp-Fa) and rhodamine (dye) (N-AuNPs-Rd), a fluorescent agent, were prepared and characterized by IR, UV, TEM, Particle size analysis and in vitro stability. The toxicity and fluorescence of N-Au was studied using zebrafish embryo model. The in vitro cytotoxicity of free Mp, N-Au-Mp and N-Au-Mp-Fa against HEp-2 cells was compared and found that the amount of Mp required to achieve 50% of growth of inhibition (IC{sub 50}) was much lower in N-Au-Mp-Fa than in free Mp and N-Au-Mp.

  11. Synthesis of 8YSZ-LSGM Composite Thick Film Ceramics for Solid Electrolyte From Nanopowder Utilizing Local Zircon Prepared Using Sol Gel Process

    Science.gov (United States)

    Syarif, Dani Gustaman; Soepriyanto, Syoni; Ismunandar, Korda, Akhmad

    2010-10-01

    Thick film ceramics of 8% mol Y2O3 doped-ZrO2 (8YSZ)-La0.8Sr0.2Ga0.2Mg0.8O3 (LSGM) composite for solid electrolyte have been synthesized from nanopowder. Concentration of LSGM was 0 and 10% weight. A paste for the thick films was made from 8YSZ nanopowder prepared using sol gel method and LSGM powder prepared by solid state reaction. Precursors for the 8YSZ nanopowder preparation were ZrOCl2ṡ8H2O derived from local zircon as byproduct of Tin processing at Bangka Island using caustic fussion method, and Y(NO3)3. The thick films were produced by screen printing technique on alumina substrates. The films were sintered at 1500° C for 2 hours in air. X-ray diffraction (XRD) data showed that the nanopowder of 8YSZ was well produced with broad peaks. The particle size of the 8YSZ powder was about 12 nm as calculated using Debye Scherrer method. The thick films of 8YSZ and 8YSZ-LSGM (90:10 in weight %) composite could be produced, however, the films still contain voids. The ionic conductance of the YSZ-10LSGM films was smaller than that of the YSZ films.

  12. Hydrocarbon Rocket Technology Impact Forecasting

    Science.gov (United States)

    Stuber, Eric; Prasadh, Nishant; Edwards, Stephen; Mavris, Dimitri N.

    2012-01-01

    Ever since the Apollo program ended, the development of launch propulsion systems in the US has fallen drastically, with only two new booster engine developments, the SSME and the RS-68, occurring in the past few decades.1 In recent years, however, there has been an increased interest in pursuing more effective launch propulsion technologies in the U.S., exemplified by the NASA Office of the Chief Technologist s inclusion of Launch Propulsion Systems as the first technological area in the Space Technology Roadmaps2. One area of particular interest to both government agencies and commercial entities has been the development of hydrocarbon engines; NASA and the Air Force Research Lab3 have expressed interest in the use of hydrocarbon fuels for their respective SLS Booster and Reusable Booster System concepts, and two major commercially-developed launch vehicles SpaceX s Falcon 9 and Orbital Sciences Antares feature engines that use RP-1 kerosene fuel. Compared to engines powered by liquid hydrogen, hydrocarbon-fueled engines have a greater propellant density (usually resulting in a lighter overall engine), produce greater propulsive force, possess easier fuel handling and loading, and for reusable vehicle concepts can provide a shorter turnaround time between launches. These benefits suggest that a hydrocarbon-fueled launch vehicle would allow for a cheap and frequent means of access to space.1 However, the time and money required for the development of a new engine still presents a major challenge. Long and costly design, development, testing and evaluation (DDT&E) programs underscore the importance of identifying critical technologies and prioritizing investment efforts. Trade studies must be performed on engine concepts examining the affordability, operability, and reliability of each concept, and quantifying the impacts of proposed technologies. These studies can be performed through use of the Technology Impact Forecasting (TIF) method. The Technology Impact

  13. Wet milling versus co-precipitation in magnetite ferrofluid preparation

    Directory of Open Access Journals (Sweden)

    Almásy László

    2015-01-01

    Full Text Available Various uses of ferrofluids for technical applications continuously raise the interest in improvement and optimization of preparation methods. This paper deals with preparation of finely granulated magnetite particles coated with oleic acid in hydrocarbon suspensions following either chemical co-precipitation from iron salt precursors or wet milling of micron size magnetite powder with the goal to compare the benefits and disadvantages of each method. Microstructural measurements showed that both methods gave similar magnetite particle size of 10-15 nm. Higher saturation magnetization was achieved for the wet-milled magnetite suspension compared to relatively rapid co-precipitation synthesis. Different efficacies of ferrophase incorporation into kerosene could be related to the different mechanisms of oleic acid bonding to nanoparticle surface. The comparative data show that wet milling represents a practicable alternative to the traditional co-precipitation since despite of longer processing time, chemicals impact on environment can be avoided as well as the remnant water in the final product.

  14. Mediterranean hydrocarbons pollution from Landsat

    OpenAIRE

    Wald, Lucien; Monget, Jean-Marie; Albuisson, Michel

    1981-01-01

    Previous studies have shown that oil spills have been viewed by Landsat . The setection of oil is mainly due to the variations of reflectance between the sea and the oil spill. This result is used in the framework of the European Project "ARCHIMEDES", lead by the Joint Research Center (Ispra, Italy), which purpose is the study of the pollution in the Mediterranean Sea. 800 Landsat images obtained from 1972 to 1975 were examined. The cumulative area covered by the hydrocarbons spread each year...

  15. Deep desulfurization of hydrocarbon fuels

    Science.gov (United States)

    Song, Chunshan [State College, PA; Ma, Xiaoliang [State College, PA; Sprague, Michael J [Calgary, CA; Subramani, Velu [State College, PA

    2012-04-17

    The invention relates to processes for reducing the sulfur content in hydrocarbon fuels such as gasoline, diesel fuel and jet fuel. The invention provides a method and materials for producing ultra low sulfur content transportation fuels for motor vehicles as well as for applications such as fuel cells. The materials and method of the invention may be used at ambient or elevated temperatures and at ambient or elevated pressures without the need for hydrogen.

  16. Preparation of ethylenediamine dinitrate

    Science.gov (United States)

    Lee, Kien-yin

    1985-01-01

    Method for the preparation of ethylenediamine dinitrate. Ethylenediamine dinitrate, a useful explosive, may readily be prepared by solvent extraction of nitrate ion from an acidic aqueous solution thereof using a high-molecular-weight, water-insoluble amine dissolved in an organic solvent, and reacting the resulting organic solution with ethylenediamine. The process of the instant invention avoids the use of concentrated nitric acid, as is currently practiced, resulting in a synthesis which is far less hazardous especially for large quantities of the explosive, and more efficient.

  17. Preparation of ethylenediamine dinitrate

    Science.gov (United States)

    Lee, K.

    1984-05-17

    Method for the preparation of ethylenediamine dinitrate. Ethylenediamine dinitrate, a useful explosive, may readily be prepared by solvent extraction of nitrate ion from an acidic aqueous solution thereof using a high-molecular-weight, water-insoluble amine dissolved in an organic solvent, and reacting the resulting oraganic solution with ethylenediamine. The process of the instant invention avoids the use of concentrated nitric acid, as is currently practiced, resulting in a synthesis which is far less hazardous, especially for large quantities of the explosive, and more efficient.

  18. Stable tetrabenzo-Chichibabin's hydrocarbons: Tunable ground state and unusual transition between their closed-shell and open-shell resonance forms

    KAUST Repository

    Zeng, Zebing

    2012-09-05

    Stable open-shell polycyclic aromatic hydrocarbons (PAHs) are of fundamental interest due to their unique electronic, optical, and magnetic properties and promising applications in materials sciences. Chichibabin\\'s hydrocarbon as a classical open-shell PAH has been investigated for a long time. However, most of the studies are complicated by their inherent high reactivity. In this work, two new stable benzannulated Chichibabin\\'s hydrocarbons 1-CS and 2-OS were prepared, and their electronic structure and geometry in the ground state were studied by various experiments (steady-state and transient absorption spectra, NMR, electron spin resonance (ESR), superconducting quantum interference device (SQUID), FT Raman, X-ray crystallographic etc.) and density function theory (DFT) calculations. 1-CS and 2-OS exhibited tunable ground states, with a closed-shell quinoidal structure for 1-CS and an open-shell biradical form for 2-OS. Their corresponding excited-state forms 1-OS and 2-CS were also chemically approached and showed different decay processes. The biradical 1-OS displayed an unusually slow decay to the ground state (1-CS) due to a large energy barrier (95 ± 2.5 kJ/mol) arising from severe steric hindrance during the transition from an orthogonal biradical form to a butterfly-like quinoidal form. The quick transition from the quinoidal 2-CS (excited state) to the orthogonal biradicaloid 2-OS (ground state) happened during the attempted synthesis of 2-CS. Compounds 1-CS and 2-OS can be oxidized into stable dications by FeCl 3 and/or concentrated H 2SO 4. The open-shell 2-OS also exhibited a large two-photon absorption (TPA) cross section (760 GM at 1200 nm). © 2012 American Chemical Society.

  19. Preparation of 3-benzyloxy-2-pyridinone functional linkers: Tools for the synthesis of 3,2-hydroxypyridinone (HOPO) and HOPO/hydroxamic acid chelators

    OpenAIRE

    Gibson, Sarah; Fernando, Rasika; Jacobs, Hollie K.; Gopalan, Aravamudan S.

    2015-01-01

    In contrast to 2,3-dihydroxypyridine, the 3-benzyloxy protected derivative, 2, undergoes facile alkylation at ambient temperatures with a variety of functionalized alkyl halides in good yields. This alkylation has been used to prepare a number of linkers that permit the attachment of 3,2-HOPO moieties onto various scaffolds using a wide range of coupling methods. The Mitsunobu reaction of 2 with representative alcohols was found to be of limited value due to competing O-alkylation that led to...

  20. Synthesis and characterization of lead oxides for preparation of nanocomposites with polyamide; Sintese e caracterizacao de oxido de chumbo para preparacao de nanocompositos com poliamida

    Energy Technology Data Exchange (ETDEWEB)

    Cado, Ronan Gorski; Severo, Vinicius A.; Bulhores, Luis Otavio S. [Centro Universitario Franciscano, Santa Maria, RS (Brazil). Programa de Pos-Graduacao em Nanociencias. Lab. de Desenvolvimento de Materiais Nanoestruturados

    2016-07-01

    Lead oxide nanoparticles with diameters between 100 to 250 nm were obtained using a polymeric precursor method in the presence of citric acid and ethylene glycol. X-ray diffraction (XRD) and dynamic light scattering to measure the size and zeta potential in solution in dispersions with different pH were used to characterize the as-obtained samples. The nanoparticles were incorporated into polyamide 6.6 and composite films were prepared by electrospinning being evaluated the variation of the mechanical properties of the polymer and its effectiveness in attenuation of X-rays. (author)

  1. Zinc oxide/polypyrrole nanocomposite as a novel solid phase microextraction coating for extraction of aliphatic hydrocarbons from water and soil samples

    Energy Technology Data Exchange (ETDEWEB)

    Amanzadeh, Hatam; Yamini, Yadollah [Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175 Tehran (Iran, Islamic Republic of); Moradi, Morteza [Department of Semiconductors, Materials and Energy Research Center, Karaj (Iran, Islamic Republic of)

    2015-07-16

    Highlights: • ZnO/polypyrrole (ZNO/PPY) nanocomposite coating was fabricated on stainless steel. • Nanocomposite coating morphology was evaluated using scanning electron microscopy. • It was applied for HS-SPME of aliphatic hydrocarbons in water and soil samples. • Separation and determination of the hydrocarbons were performed by GC-FID. • The method is suitable for routine analysis of n-alkanes in various environmental samples. - Abstract: In this work, ZnO/PPy nanocomposite coating was fabricated on stainless steel and evaluated as a novel headspace solid phase microextraction (HS-SPME) fiber coating for extraction of ultra-trace amounts of environmental pollutants; namely, aliphatic hydrocarbons in water and soil samples. The ZnO/PPy nanocomposite were prepared by a two-step process including the electrochemical deposition of PPy on the surface of stainless steel in the first step, and the synthesis of ZnO nanorods by hydrothermal process in the pores of PPy matrix in the second step. Porous structure together with ZnO nanorods with the average diameter of 70 nm were observed on the surface by using scanning electron microscopy (SEM). The effective parameters on HS-SPME of hydrocarbons (i.e., extraction temperature, extraction time, desorption temperature, desorption time, salt concentration, and stirring rate) were investigated and optimized by one-variable-at-a-time method. Under optimized conditions (extraction temperature, 65 ± 1 °C; extraction time, 15 min; desorption temperature, 250 °C; desorption time, 3 min; salt concentration, 10% w/v; and stirring rate, 1200 rpm), the limits of detection (LODs) were found in the range of 0.08–0.5 μg L{sup −1}, whereas the repeatability and fiber-to-fiber reproducibility were in the range 5.4–7.6% and 8.6–10.4%, respectively. Also, the accuracies obtained for the spiked n-alkanes were in the range of 85–108%; indicating the absence of matrix effects in the proposed HS-SPME method. The results

  2. Hydrocarbon Reserves: Abundance or Scarcity

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    IFP and the OAPEC jointly organize a regular international seminar dealing with world oil-related problems appearing in the news. For the first time, this seminar has been opened to oil and gas company specialists, service companies, research centers and independents. This year's theme concerns oil and gas reserves: are they abundant or are we headed towards the shortages announced by some experts? This theme is especially topical in that: oil and gas currently meet two thirds of world energy needs and almost completely dominate the transport sector; the reserves declared by the OAPEC countries account for nearly half of world reserves; the price of a barrel of oil went through the roof in 2004; world energy demand is growing fast and alternative sources of energy are far from ready to take over from oil and gas in the next few decades. Since the reserves correspond to the volume it is technically and economically viable to produce, the seminar has, of course, dealt with the technical and economic questions that arise in connection with exploration and production, but it has also considered changes in the geopolitical context. Presentations by the leading companies of the OAPEC countries and by the IFP group were completed by presentation from the International Energy Agency (IEA), the United States Geological Survey (USGS), the IHS Energy Group, Total and Gaz de France. This document gathers the transparencies of the following presentations: Hydrocarbon reserves in OAPEC members countries: current and future (M. Al-Lababidi); Non OAPEC liquid reserves and production forecasts (Y. Mathieu); World oil and gas resources and production outlook (K. Chew); Global investments in the upstream (F. Birol); Total's policy in the oil and gas sector (C. de Margerie); Gaz de France's policy in the oil and gas sector (J. Abiteboul); NOC/IOC's opportunities in OPEC countries (I. Sandrea); Relationships between companies, countries and investors: How they may

  3. Process for the preparation of aromatic compounds

    NARCIS (Netherlands)

    Schenk, N.J.; Biesbroek, Arnold; Heeres, André; Heeres, Hero

    2015-01-01

    Aromatic compounds are prepared from a feed stream comprising biomass or a mixture of biomass and synthetic polymer in a process, comprising: a) subjecting the feed stream to a pyrolysis treatment in the presence of a cracking catalyst to yield a vaporous fraction comprising hydrocarbons with

  4. SYNTHESIS AND ANALYSIS OF ARYL METHYL AMINES

    OpenAIRE

    YULDASHEVA MUKHABBAT RAZZOQBERDIEVNA

    2016-01-01

    Synthesis of alkyl amines derivatives of aromatic hydrocarbons. The structure of the obtained 2,4-demethylbenzylamine, 2,5dimethybenzylamine, 2,4,6-threemethyl 3,5-di (N-aminomethyl) nitrobenzene was determined by means of IR spectroscopy and chromato-mass-spectrometry.

  5. Synthesis of new porphyrins with peripheral conjugated chelates and their use for the preparation of porphyrin dimers linked by metal ions.

    Science.gov (United States)

    Richeter, Sébastien; Jeandon, Christophe; Gisselbrecht, Jean-Paul; Graff, Roland; Ruppert, Romain; Callot, Henry J

    2004-01-12

    This article describes the preparation of several new porphyrins bearing chelating peripheral groups fully conjugated with the macrocyclic pi-system. Treatment of a 2-nitro-meso-tetraarylporphyrin with phosphite gave a cyclic enamine, whose formylation gave an enaminoaldehyde. The thio analogue was obtained on treatment with Lawesson's reagent. The same reagent was also used to obtain the isomeric thioenaminoketone chelates. A enaminoketone ligand was prepared from a porphyrinic pyrrolone. All these ligands, as internal nickel complexes, could be metalated with palladium to yield porphyrinic dimers. The dimers obtained from enaminoketones and thioketones show a trans geometry, while in the enaminoaldehyde and -thioaldehyde series the cis isomer is thermodynamically favored. The bathochromic shifts of the electronic spectra of the aldehyde-derived dimers illustrate the strong electronic effect of peripheral metalation and dimerization. However, in the case of the pyrrolone-derived ligand, opposite effects were observed, due to partial reconstitution of the porphyrin chromophore on complexation. As with the dimers derived from enaminoketones, the dimers derived from the new ligands show typical splitting (up to 190 mV) of the electrochemical waves confirming large porphyrin-porphyrin interactions.

  6. Specific Conjugation of the Hinge Region for Homogeneous Preparation of Antibody Fragment-Drug Conjugate: A Case Study for Doxorubicin-PEG-anti-CD20 Fab' Synthesis.

    Science.gov (United States)

    Zhou, Zhan; Zhang, Jing; Zhang, Yan; Ma, Guanghui; Su, Zhiguo

    2016-01-20

    Conventional preparation strategies for antibody-drug conjugates (ADCs) result in heterogeneous products with various molecular sizes and species. In this study, we developed a homogeneous preparation strategy by site-specific conjugation of the anticancer drug with an antibody fragment. The model drug doxorubicin (DOX) was coupled to the Fab' fragment of anti-CD20 IgG at its permissive sites through a heterotelechelic PEG linker, generating an antibody fragment-drug conjugate (AFDC). Anti-CD20 IgG was digested and reduced specifically with β-mercaptoethylamine to generate the Fab' fragment with two free mercapto groups in its hinge region. Meanwhile, DOX was conjugated with α-succinimidylsuccinate ω-maleimide polyethylene glycol (NHS-PEG-MAL) to form MAL-PEG-DOX, which was subsequently linked to the free mercapto containing Fab' fragment to form a Fab'-PEG-DOX conjugate. The dual site-specific bioconjugation was achieved through the combination of highly selective reduction of IgG and introduction of heterotelechelic PEG linker. The resulting AFDC provides an utterly homogeneous product, with a definite ratio of one fragment to two drugs. Laser confocal microscopy and cell ELISA revealed that the AFDC could accumulate in the antigen-positive Daudi tumor cell. In addition, the Fab'-PEG-DOX retained appreciable targeting ability and improved antitumor activity, demonstrating an excellent therapeutic effect on the lymphoma mice model for better cure rate and significantly reduced side effects.

  7. Preparation of 3-benzyloxy-2-pyridinone functional linkers: Tools for the synthesis of 3,2-hydroxypyridinone (HOPO) and HOPO/hydroxamic acid chelators.

    Science.gov (United States)

    Gibson, Sarah; Fernando, Rasika; Jacobs, Hollie K; Gopalan, Aravamudan S

    2015-12-08

    In contrast to 2,3-dihydroxypyridine, the 3-benzyloxy protected derivative, 2, undergoes facile alkylation at ambient temperatures with a variety of functionalized alkyl halides in good yields. This alkylation has been used to prepare a number of linkers that permit the attachment of 3,2-HOPO moieties onto various scaffolds using a wide range of coupling methods. The Mitsunobu reaction of 2 with representative alcohols was found to be of limited value due to competing O-alkylation that led to product mixtures. The phthalimide 3j can be converted in two steps to HOPO isocyanate 6 in excellent yields. Isocyanate 6 can be coupled to amines at room temperature or to alcohols in refluxing dichloroethane to obtain the corresponding urea or carbamate linked ligand systems. The coupling of isocyanate 6 with TREN followed by deprotection gave the tris-HOPO 10, an interesting target as it has both cationic and anionic binding sites. The HOPO hydroxylamine linker 11 was shown to be especially valuable as its coupling with carboxylic acids proceeds with the concomitant generation of an additional hydroxamate ligand moiety in the framework. The utility of this linker was shown by the preparation of two mixed HOPO-hydroxamate chelators, 16 and 19, based on the structure of desferrioxamine, a well-known trihydroxamate siderophore.

  8. Biosynthesis of vitamin B12: the preparative multi-enzyme synthesis of precorrin-3A and 20-methylsirohydrochlorin (a 2,7,20-trimethylisobacteriochlorin).

    Science.gov (United States)

    Stamford, N P; Crouzet, J; Cameron, B; Alanine, A I; Pitt, A R; Yeliseev, A A; Battersby, A R

    1996-01-01

    The Bacillus subtilis genes hemB, hemC and hemD, encoding respectively the enzymes porphobilinogen synthase, hydroxymethylbilane synthase and uroporphyrinogen III synthase, have been expressed in Escherichia coli using a single plasmid construct. An enzyme preparation from this source converts 5-aminolaevulinic acid (ALA) preparatively and in high yield into uroporphyrinogen III. The Pseudomonas denitrificans genes cobA and cobI, encoding respectively the enzymes S-adenosyl-L-methionine:uroporphyrinogen III methyltransferase (SUMT) and S-adenosyl-L-methionine:precorrin-2 methyltransferase (SP2MT), were also expressed in E. coli. When SUMT was combined with the coupled-enzyme system that produces uroporphyrinogen III, precorrin-2 was synthesized from ALA, and when SP2MT was also added the product from the coupling of five enzymes was precorrin-3A. Both of these products are precursors of vitamin B12, and they can be used directly for biosynthetic experiments or isolated as their didehydro octamethyl esters in > 40% overall yield. The enzyme system which produces precorrin-3A is sufficiently stable to allow long incubations on a large scale, affording substantial quantities (15-20 mg) of product.

  9. Synthesis, characterization and electrochemical characterization of lead selenide sub-micron particles capped with a benzoate ligand and prepared at different temperatures

    Science.gov (United States)

    Rodríguez-Rodríguez, Weyshla A.; Colón, Jadiel; Guzmán, Roger; Rivera, Harry; Santiago-Berríos, Mitk'El B.

    2014-09-01

    Semiconductor materials offer several potential benefits as active elements in the development of harvesting-energy conversion technologies. In particular, lead selenide (PbSe) semiconductors have been used and proposed to design solar energy harvesting devices, IR sensors, FET devices, etc. Lead salts have drawn particular attention from the applied and fundamental research communities due to their exceptionally strong quantum confinement effects. Several syntheses of PbSe have been proposed using long chain surfactants to allow the formation of particles and nanoparticles. Here we present a synthesis using benzoic acid as the capping ligand in ambient atmosphere. Although the particles are not in nanometric size, we compare the crystal structure (using x-ray powder diffraction data), the near infrared and mid-infrared absorption properties of PbSe using oleic acid as the capping ligand with PbSe using benzoic acid as the capping ligand. The new synthetized particles were shown to have similar crystal structure and absorb light in the near infrared region at 1410 nm. We also performed cyclic voltammetry of these particles drop-casted in the surface of a glassy carbon electrode. The particles showed electrochemical behavior with an oxidation peak near (-402 ± 5 mV) versus Ag/AgCl reference electrode. The particles seem to form a polymeric film at the surface of a glassy carbon electrode.

  10. In situ immobilized lipase on the surface of intracellular polyhydroxybutyrate granules: preparation, characterization, and its promising use for the synthesis of fatty acid alkyl esters.

    Science.gov (United States)

    Yang, Taek Ho; Kwon, Min-A; Lee, Ji Young; Choi, Ji-Eun; Oh, Joon Young; Song, Jae Kwang

    2015-12-01

    Photobacterium lipolyticum M37 lipase (LipM37) was immobilized on the surface of intracellular polyhydroxybutyrate (PHB) granules in Escherichia coli. LipM37 was genetically fused to Cupriavidus necator PHA synthase (PhaC Cn ), and the engineered PHB operon containing the lip M37 -phaC Cn successfully mediated the accumulation of PHB granules (85 wt.%) inside E. coli cells. The PHB granules were isolated from the crude cell extract, and the immobilized LipM37 was comparable with the free form of LipM37 except for a favorable increase in thermostability. The immobilized LipM37 was used to synthesize oleic acid methyl ester (biodiesel) and oleic acid dodecyl ester (wax ester), and yielded 98.0 % conversion in esterification of oleic acid and dodecanol. It was suggested that the LipM37-PhaCCn fusion protein successfully exhibited bifunctional activities in E. coli and that in situ immobilization of lipase to the intracellular PHB could be a promising approach for expanding the biocatalytic toolbox for industrial chemical synthesis.

  11. Effect of Water Content in Ethylene Glycol Solvent on the Size of ZnO Nanoparticles Prepared Using Microwave Solvothermal Synthesis

    Directory of Open Access Journals (Sweden)

    Jacek Wojnarowicz

    2016-01-01

    Full Text Available Zinc oxide nanoparticles (ZnO NPs were obtained by the microwave solvothermal synthesis (MSS method. The precursor of the MSS reaction was a solution of hydrated zinc acetate in ethylene glycol with water addition. It was proved that by controlling the water concentration in the precursor it was possible to control the size of ZnO NPs in a programmed manner. The less the water content in the precursor, the smaller the size of ZnO NPs obtained. The obtained NPs with the average particle size ranging from 25 nm to 50 nm were characterised by homogeneous morphology and a narrow distribution of particle sizes. The following parameters of the obtained ZnO NPs were determined: pycnometric density, specific surface area, phase purity, chemical composition, lattice parameters, average particle size, and particle size distribution. The average size of ZnO NPs was determined using Scherrer’s formula, Nanopowder XRD Processor Demo web application, by converting the results of the specific surface area, and TEM tests using the dark field technique. ZnO morphology and structure were determined using scanning electron microscopy (SEM and transmission electron microscopy (TEM. The test performed by the X-ray powder diffraction (XRD confirmed that crystalline ZnO, pure in terms of phase, had been obtained.

  12. Sonochemical synthesis of nano lead(II) metal-organic coordination polymer; New precursor for the preparation of nano-materials.

    Science.gov (United States)

    Mirtamizdoust, Babak

    2017-03-01

    Nano-sheets of a novel Pb(II)-based 3D metal-organic coordination polymer [Pb2(nih)2(NO3)4(CH3OH)]n (1) were synthesized by a branched-tube method and sonochemical reaction. The synthesis was done using various times, concentrations of initial reagents, and irradiation power. The compound was characterized by scanning electron microscopy (SEM), elemental analysis, IR spectroscopy, thermogravimetric analysis (TGA), differential thermal analysis (DTA), X-ray powder diffraction (XRD), and single-crystal X-ray analysis. The X-ray analysis of the structures revealed the composition and stereochemistry of the basic building block, which had with a formula of {Pb2(nih)2(NO3)4(CH3OH)}. These blocks are connected by covalent bonds originating from the nih and nitrate ligands and form infinite 3D metal-organic polymeric chains. The effect of triethylamine on the speed of nucleation was also investigated. Lead oxide nanoparticles were obtained by thermolysis of 1 at 180°C using oleic acid as a surfactant. The average diameter of the nanoparticles was estimated by XRD to be 36nm. The morphology and size of the PbO nanoparticles were also studied using SEM. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Amphiphilic triblock copolymers with PEGylated hydrocarbon structures as environmentally friendly marine antifouling and fouling-release coatings.

    Science.gov (United States)

    Zhou, Zhaoli; Calabrese, David R; Taylor, Warren; Finlay, John A; Callow, Maureen E; Callow, James A; Fischer, Daniel; Kramer, Edward J; Ober, Christopher K

    2014-01-01

    The ideal marine antifouling (AF)/fouling-release (FR) coating should be non-toxic, while effectively either resisting the attachment of marine organisms (AF) or significantly reducing their strength of attachment (FR). Many recent studies have shown that amphiphilic polymeric materials provide a promising solution to producing such coatings due to their surface dual functionality. In this work, poly(ethylene glycol) (PEG) of different molecular weights (Mw = 350, 550) was coupled to a saturated difunctional alkyl alcohol to generate amphiphilic surfactants (PEG-hydrocarbon-OH). The resulting macromolecules were then used as side chains to covalently modify a pre-synthesized PS8 K-b-P(E/B)25 K-b-PI10 K (SEBI or K3) triblock copolymer, and the final polymers were applied to glass substrata through an established multilayer surface coating technique to prepare fouling resistant coatings. The coated surfaces were characterized with AFM, XPS and NEXAFS, and evaluated in laboratory assays with two important fouling algae, Ulva linza (a green macroalga) and Navicula incerta, a biofilm-forming diatom. The results suggest that these polymer-coated surfaces undergo surface reconstruction upon changing the contact medium (polymer/air vs polymer/water), due to the preferential interfacial aggregation of the PEG segment on the surface in water. The amphiphilic polymer-coated surfaces showed promising results as both AF and FR coatings. The sample with longer PEG chain lengths (Mw = 550 g mol(-1)) exhibited excellent properties against both algae, highlighting the importance of the chemical structures on ultimate biological performance. Besides reporting synthesis and characterization of this new type of amphiphilic surface material, this work also provides insight into the nature of PEG/hydrocarbon amphiphilic coatings, and this understanding may help in the design of future generations of fluorine-free, environmentally friendly AF/FR polymeric coatings.

  14. Biosyngas Fischer. Tropsch conversion by high Fe loaded supported catalysts prepared with ultrasound and microwave

    Energy Technology Data Exchange (ETDEWEB)

    Pirola, C.; Di Fronzo, A.; Boffito, D.C.; Bianchi, C. [Milano Univ. (Italy). Dipt. di Chimica; Di Michele, A. [Perugia Univ. (Italy). Dipt. di Fisica

    2012-07-01

    Catalysts with iron high loading of 30 wt%, promoted with K (2.0 wt%) and Cu (3.75 wt%), have been synthesized according to three different methods: (1) the traditional impregnation method (TR); (2) Ultrasound (US) assisted TR method; (3) Microwave (MW) assisted TR method. All the samples have been fully characterized by BET, ICP/OES, XRPD, TG-DTA, FT-IR, TPR, SEM and TEM and tested in a laboratory pilot plant for Fischer-Tropsch synthesis working at 220 C and 20 bar. The results of the catalysts characterization indicated that the morphology of the samples strongly depends on the method of preparation. The best FTS results in term of C{sub 2+} yield (41%) has been obtained using MW with a good value of the selectivity towards heavy hydrocarbons, while in term of CO conversion (58%), using US. The samples prepared with non-traditional methods show FTS better results, probably due to a more wide and uniform distribution of Fe in the medium during the synthesis phase. (orig.)

  15. Before the Bonanza: Hydrocarbons in Greenland

    OpenAIRE

    Meinild, Ebbe Dam

    2010-01-01

    The issue of Greenlandic hydrocarbons gradually moved towards the centre of the creation of autonomous Greenland. Hydrocarbons in Greenland and the Greenlandic nation were co-produced in the same process. Thus, when hydrocarbons were connected to an ecological modernisation it allowed the newly formed Home Rule administration, in a joint Danish-Greenlandic effort, to adopt this, not only as a road to independence, but as something giving credibility to Greenland as a distinct society.

  16. Comparing hydrogen and hydrocarbon booster fuels

    Science.gov (United States)

    Martin, James A.

    1988-01-01

    The present evaluation of the consequences of hydrogen and hydrocarbon fuels as the basis of launch vehicle booster rocket-stage performance notes that hydrocarbon fuels lead to lower vehicle dry mass, for low-velocity requirements, while hydrogen fuel furnishes lower dry mass. Vehicles employing both types of fuel attempt to take advantage of the low intercept and slope of hydrocarbon fuel at low velocity, and subsequently, of the slope of the hydrogen curves at higher velocities.

  17. HYDROCARBON AND SULFUR SENSORS FOR SOFC SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    A.M. Azad; Chris Holt; Todd Lesousky; Scott Swartz

    2003-11-01

    The following report summarizes work conducted during the Phase I program Hydrocarbon and Sulfur Sensors for SOFC Systems under contract No. DE-FC26-02NT41576. For the SOFC application, sensors are required to monitor hydrocarbons and sulfur in order to increase the operation life of SOFC components. This report discusses the development of two such sensors, one based on thick film approach for sulfur monitoring and the second galvanic based for hydrocarbon monitoring.

  18. Evaluation of mineral oil saturated hydrocarbons (MOSH and mineral oil aromatic hydrocarbons (MOAH in pure mineral hydrocarbon-based cosmetics and cosmetic raw materials using 1H NMR spectroscopy [version 2; referees: 3 approved

    Directory of Open Access Journals (Sweden)

    Dirk W. Lachenmeier

    2017-08-01

    Full Text Available Mineral hydrocarbons consist of two fractions, mineral oil saturated hydrocarbons (MOSH and mineral oil aromatic hydrocarbons (MOAH. MOAH is a potential public health hazard because it may include carcinogenic polycyclic compounds. In the present study, 400 MHz nuclear magnetic resonance (NMR spectroscopy was introduced, in the context of official controls, to measure MOSH and MOAH in raw materials or pure mineral hydrocarbon final products (cosmetics and medicinal products. Quantitative determination (qNMR has been established using the ERETIC methodology (electronic reference to access in vivo concentrations based on the PULCON principle (pulse length based concentration determination. Various mineral hydrocarbons (e.g., white oils, paraffins or petroleum jelly were dissolved in deuterated chloroform. The ERETIC factor was established using a quantification reference sample containing ethylbenzene and tetrachloronitrobenzene. The following spectral regions were integrated: MOSH δ 3.0 – 0.2 ppm and MOAH δ 9.2 - 6.5, excluding solvent signals. Validation showed a sufficient precision of the method with a coefficient of variation <6% and a limit of detection <0.1 g/100 g. The applicability of the method was proven by analysing 27 authentic samples with MOSH and MOAH contents in the range of 90-109 g/100 g and 0.02-1.10 g/100 g, respectively. It is important to distinguish this new NMR-approach from the hyphenated liquid chromatography-gas chromatography methodology previously used to characterize MOSH/MOAH amounts in cosmetic products. For mineral hydrocarbon raw materials or pure mineral hydrocarbon-based cosmetic products, NMR delivers higher specificity without any sample preparation besides dilution. Our sample survey shows that previous methods may have overestimated the MOAH amount in mineral oil products and opens new paths to characterize this fraction. Therefore, the developed method can be applied for routine monitoring of consumer

  19. Evaluation of mineral oil saturated hydrocarbons (MOSH and mineral oil aromatic hydrocarbons (MOAH in pure mineral hydrocarbon-based cosmetics and cosmetic raw materials using 1H NMR spectroscopy [version 1; referees: 2 approved, 1 approved with reservations

    Directory of Open Access Journals (Sweden)

    Dirk W. Lachenmeier

    2017-05-01

    Full Text Available Mineral hydrocarbons consist of two fractions, mineral oil saturated hydrocarbons (MOSH and mineral oil aromatic hydrocarbons (MOAH. MOAH is a potential public health hazard because it may include carcinogenic polycyclic compounds. In the present study, 400 MHz nuclear magnetic resonance (NMR spectroscopy was introduced, in the context of official controls, to measure MOSH and MOAH in raw materials or pure mineral hydrocarbon final products (cosmetics and medicinal products. Quantitative determination (qNMR has been established using the ERETIC methodology (electronic reference to access in vivo concentrations based on the PULCON principle (pulse length based concentration determination. Various mineral hydrocarbons (e.g., white oils, paraffins or petroleum jelly were dissolved in deuterated chloroform. The ERETIC factor was established using a quantification reference sample containing ethylbenzene and tetrachloronitrobenzene. The following spectral regions were integrated: MOSH δ 3.0 – 0.2 ppm and MOAH δ 9.2 - 6.5, excluding solvent signals. Validation showed a sufficient precision of the method with a coefficient of variation <6% and a limit of detection <0.1 g/100 g. The applicability of the method was proven by analysing 27 authentic samples with MOSH and MOAH contents in the range of 90-109 g/100 g and 0.02-1.10 g/100 g, respectively. It is important to distinguish this new NMR-approach from the hyphenated liquid chromatography-gas chromatography methodology previously used to characterize MOSH/MOAH amounts in cosmetic products. For mineral hydrocarbon raw materials or pure mineral hydrocarbon-based cosmetic products, NMR delivers higher specificity without any sample preparation besides dilution. Our sample survey shows that previous methods may have overestimated the MOAH amount in mineral oil products and opens new paths to characterize this fraction. Therefore, the developed method can be applied for routine monitoring of consumer

  20. Synthesis and photocatalytic application of α-Fe2O3/ZnO fine particles prepared by two-step chemical method

    Directory of Open Access Journals (Sweden)

    Patij Shah

    2013-06-01

    Full Text Available Composite iron oxide-Zinc oxide (α-Fe2O3/ZnO was synthesized by two-step method: in the first one step uniform α-Fe2O3 particles were prepared through a hydrolysis process of ferric chloride at 80 °C. In the second step, the ZnO particles were included in the α-Fe2O3 particles by a zinc acetate [Zn(Ac2·2H2O] assisted hydrothermal method at low temperature (90°C±C. The α-Fe2O3 and ZnO phases were identified by XRD, energy dispersive X-ray analysis (EDX. The photoreactivities of α-Fe2O3/ZnO nanoparticles under UV irradiation were quantified by the degradation of formaldehyde.

  1. Synthesis and self-assembly of Chitosan-g-Polystyrene copolymer: A new route for the preparation of heavy metal nanoparticles

    KAUST Repository

    Francis, Raju S.

    2015-01-01

    Amphiphilic graft copolymers made of a Chitosan (CS) backbone and three arm polystyrene (PS) grafts were prepared by "grafting onto" strategy using Toluene Diisocyanate. IR spectroscopy and SEC show the successful grafting process. SEM pictures of Chitosan-g-Polystyrene (CS-g-PS) indicate a spherulite like surface and exhibit properties that result from the disappearance of Chitosan crystallinity. The introduced polystyrene star grafts units improve hydrophobic properties considerably as confirmed by the very high solubility of (CS-g-PS) in organic solvents. The graft copolymer which self-assembles into polymeric micelles in organic media demonstrates much better adsorption of transition and inner transition metal ions than pure Chitosan whose amine groups are not necessarily available due to crystallinity.

  2. Preparation of Hollow N-Chloramine-Functionalized Hemispherical Silica Particles with Enhanced Efficacy against Bacteria in the Presence of Organic Load: Synthesis, Characterization, and Antibacterial Activity.

    Science.gov (United States)

    Rahma, Hakim; Asghari, Sogol; Logsetty, Sarvesh; Gu, Xiaochen; Liu, Song

    2015-06-03

    The fabrication of highly effective antimicrobial materials is an important strategy for coping with the growing concern of bacterial resistance. In this study, N-chloramine-functionalized hollow hemispherical structures were designed and prepared to examine possible enhancement of antimicrobial performance. Antimicrobial testing was carried out on Gram-negative (Escherichia coli) and Gram-positive (Baccilus Cereus) bacteria in the presence and absence of biological medium. The efficacy of the hollow hemispherical particles functionalized with various N-chloramines in killing bacteria was compared among themselves with that of small organic molecules and spherical particles to investigate the effect of the surface charge, chemical structure, and shape of the particles. Results demonstrated that quaternary ammonium salt or amine functions in the chemical structure enhanced the antimicrobial activity of the particles and made the particles more effective than the small molecules in the presence of biological medium. The importance of particle shape in the killing tests was also confirmed.

  3. Cyanoacetanilides intermediates in heterocyclic synthesis. Part 6: Preparation of some hitherto unknown 2-oxopyridine, bipyridine, isoquinoline and chromeno[3,4-c]pyridine containing sulfonamide moiety

    Directory of Open Access Journals (Sweden)

    Yousry A. Ammar

    2014-11-01

    Full Text Available Treatment of cyanoacetanilide derivative 1 with tetracyanoethylene (2 in dioxane/triethylamine furnished 2-pyridone derivative 6. Aminopyridine 9 was obtained by cyclization of compound 1 with ketene dithioacetal 7/EtONa. Cyclocondensation of 1 with malononitrile and/or acetylacetone (1:1 M ratio gave pyridine derivatives 11 and 13. Ternary condensation of compound 1, aliphatic aldehydes and malononitrile (1:1:1 M ratio yielded the 2-pyridones 20a and b. Bipyridines 22a–c were prepared by refluxing of compound 21 with active methylene reagents. Cyclization of chromene derivatives 24 and 28 with malononitrile produced the novel chromeno[3,4-c]pyridine 26 and pyrano[3′,2′:6,7]chromeno[3,4-c]pyridine 29.

  4. Preparation of (+)- and (-)- β-phenyl- and β-(4-chlorophenyl)-γ- butyro lactones: Key intermediates in the synthesis of β-phenyl-Gaba and baclofene

    Energy Technology Data Exchange (ETDEWEB)

    Gomez G, J.; Melendez R, M.; Suarez C, O. R.; Castelan D, L. E.; Fragoso V, M. J.; Lopez V, E.; Sanchez Z, M., E-mail: melendez@uaeh.edu.mx [Universidad Autonoma del Estado de Hidalgo, Area Academica de Quimica, Carretera Pachuca-Tulancingo Km. 4.5, Mineral de la Reforma 42184, Hidalgo (Mexico)

    2014-07-01

    the preparation of β-phenyl- and β-(4-chlorophenyl)-γ-butyro lactones (±)-4 and their resolution to the corresponding (+)-(S)-3, (-)-(R)-3 and (+)-(S)-4, (-)-(R)-4 through formation, flash column chromatography separation and subsequent hydrolysis of dia stereoisomeric 4-hydroxybutyramide s (2'R,3S)-5, (2'R,3R)-5, (2'R,3S)-6 and (2'R,3R)-6 is described. The absolute configuration assignment of enantiopure 3 and 4 was supported by X-ray crystallographic structures of (2'R,3R)-5, (2'R,3S)-6 and (2'R,3R)-6. (Author)

  5. STUDY OF THE PREPARATION OF SUGAR FROM HIGH-LIGNIN LIGNOCELLULOSE APPLYING SUBCRITICAL WATER AND ENZYMATIC HYDROLYSIS: SYNTHESIS AND CONSUMABLE COST EVALUATION

    Directory of Open Access Journals (Sweden)

    HANNY F. SANGIAN

    2015-05-01

    Full Text Available This study concern sugars hydrolyzed from the high-lignin coconut coir dust using moderate subcritical water (SCW hydrolysis at pressures 20-40 bar for 1 h and to evaluate the consumable costs driver generated. The SCW method produced two products, sugar liquid and solid (SCW-treated substrate. The solid was proceeded to prepare the sugar via enzymatic hydrolysis using pure cellulase. Yield of sugar hydrolyzed from lignocellulose by SCW technique was 0.25 gram sugar/gram cellulose +hemicellulose, or 0.09-gram sugar/gram lignocellulose at 160 °C and 40 bar. While, the maximum yield of sugar liberated enzymatically from SCW-treated solid was 0.35-gram sugar/gram cellulose+hemicellulose, or 0.13-gram sugar/gram SCW-treated solid. It was found that carbon dioxide gas was the highest cost driving in SCW hydrolysis.

  6. Synthesis and characterization of MoS2/Ti composite coatings on Ti6Al4V prepared by laser cladding

    Directory of Open Access Journals (Sweden)

    Rongjuan Yang

    2013-02-01

    Full Text Available The MoS2/Ti composite coating with sub-micron grade structure has been prepared on Ti6Al4V by laser method under argon protection. The morphology, microstructure, microhardness and friction coefficient of the coating were examined. The results indicated that the molybdenum disulfide was decomposed during melting and resolidification. The phase organization of composite coating mainly consisted of ternary element sulfides, molybdenum sulfides and titanium sulfides. The friction coefficient of and the surface roughness the MoS2/Ti coating were lower than those of Ti6Al4V. The composite coating exhibits excellent adhesion to the substrates, less surface roughness, good wear resistance and harder surface.

  7. Synthesis and characterization of novel functional electrosterically stabilized colloidal particles prepared by emulsion polymerization using a strongly ionized amphiphilic diblock copolymer.

    Science.gov (United States)

    Mohanty, P S; Dietsch, H; Rubatat, L; Stradner, A; Matsumoto, K; Matsuoka, H; Schurtenberger, P

    2009-02-17

    Amphiphilic diblock copolymers such as poly(styrene)-block-poly(styrene sulfonate) (PS-b-PSS) (Matsuoka, H.; Maeda, S.; Kaewsaiha, P.; Matsumoto, K. Langmuir 2004, 20, 7412), belong to a class of new polymeric surfactants that ionize strongly in aqueous media. We investigated their self-assembly behavior in aqueous solutions and used them as an emulsifier to prepare electrosterically stabilized colloidal particles of different diameters between 70 to 400 nm. We determined the size, size polydispersity, effective charge, total dissociable charge, structural ordering, and phase behavior using light scattering, transmission electron microscopy (TEM), small-angle neutron scattering (SANS), and potentiometric titration. These experiments clearly demonstrated that all of the synthesized particles were nearly monodisperse (polydispersity indexpolyelectrolyte brush shell. Finally, these monodisperse particles were found to self-assemble into 3D ordered colloidal crystalline arrays at a low volume fraction (=0.00074) that diffract light in the visible region.

  8. Fischer-Tropsch Synthesis on ALD-synthesized Catalysts

    Science.gov (United States)

    Van Norman, Staci A.

    Cobalt catalysts were prepared on porous Al2O 3 and W/Al2O3 supports by atomic layer deposition (ALD) that used sequential reactions of cobaltocene (CoCp2) and H 2 at 483 to 523 K. This preparation method avoided formation of an intermediate oxide, so the catalysts could be activated at lower temperatures. Some of these catalysts had CO reaction rates per g of Co in Fischer-Tropsch synthesis (FTS) that were three times those reported for Co catalysts prepared by incipient wetness. The FTS reacts CO and H2 to form hydrocarbon liquids that can used as synthetic fuels. The rate of FTS depended on the number of ALD cycles, and catalysts prepared with one cycle had activities equivalent to incipient wetness Co catalysts; the highest reaction rate per g of catalyst was obtained for catalysts prepared using four ALD cycles. Two types of Co were observed on the alumina surface using TEM: Co particles with diameters between 0.6 and 1.8 nm (75% were smaller than 1 nm), and Co crystalline planes that were as large as 35 nm. Cobalt catalysts prepared by ALD retained adsorbed ligands that appeared to be stable for at least eight months at room temperature. Tungsten was deposited onto porous Al2O 3 by ALD to provide a catalyst support with higher thermal conductivity because the FTS reaction is highly exothermic. The W indeed increased thermal conductivity, and the resulting supports were used for Co ALD following deposition of an Al2O3 ALD layer. However, although Co deposits on ALD Al2O3, the Co had no activity for FTS, apparently because the ALD Al2O3 was amorphous. In contrast ALD Al 2O3 that was heat treated at high temperature was partially crystalline and served as a support for an active FTS catalyst.

  9. Liquid-phase combinatorial synthesis.

    OpenAIRE

    Han, H; Wolfe, M M; Brenner, S; Janda, K D

    1995-01-01

    A concept termed liquid-phase combinatorial synthesis (LPCS) is described. The central feature of this methodology is that it combines the advantages that classic organic synthesis in solution offers with those that solid-phase synthesis can provide, through the application of a linear homogeneous polymer. To validate this concept two libraries were prepared, one of peptide and the second of nonpeptide origin. The peptide-based library was synthesized by a recursive deconvolution strategy [Er...

  10. Synthesis of a sugar-organometallic compound 1,1 Prime -difurfurylferrocene and its microwave preparation of carbon/iron oxide nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Shanyu, E-mail: syzhao65@gmail.com [School of Environmental and Safty Engineering, Changzhou University, Changzhou, Jiangsu 213164 (China); Department of Chemistry, Brown University, Providence, RI 02912-9108 (United States); Cooper, Daniel C. [Department of Chemistry, Brown University, Providence, RI 02912-9108 (United States); Xu, Haixun [Institute of Building Materials, Dalian University of Technology, Dalian, Liaoning 116024 (China); Zhu Pinghua [School of Environmental and Safty Engineering, Changzhou University, Changzhou, Jiangsu 213164 (China); Suggs, J. William, E-mail: j_suggs@brown.edu [Department of Chemistry, Brown University, Providence, RI 02912-9108 (United States)

    2013-01-01

    Graphical abstract: In order to synthesize a carbon-metal or metal oxide combination sphere, carbonaceous resource furfural was introduced, which was nucleophilic treated with 1,1 Prime -dilithioferrocene to form a sugar-organometallic compound: ferrocenyl monosaccharide derivative 1,1 Prime -difurfurylferrocene, which can be hydrothermally treated in a microwave reactor to give 300-500 nm microspheres with the {alpha}-Fe{sub 2}O{sub 3} or Fe{sub 3}O{sub 4} formed on the surface, which may be favorable for new magnetic materials preparation or instead of iron with other metal ions, versatile carbon/metal composites will be possibly synthesized for catalysis, drug delivery and magnetic uses. Highlights: Black-Right-Pointing-Pointer We synthesized 1,1 Prime -difurfurylferrocene by nucleophilic treating furfural with 1,1 Prime -dilithioferrocene. Black-Right-Pointing-Pointer 1,1 Prime -Difurfurylferrocene can be hydrothermally treated by microwave to give microspheres with iron oxides on the surface. Black-Right-Pointing-Pointer 1,1 Prime -Difurfurylferrocene has 2 reactive furanose units, which form carbonspheres and ferrocenyl can give iron oxides. Black-Right-Pointing-Pointer REDOX atmosphere influences the coating structures. - Abstract: In order to synthesize a carbon-metal or metal oxide combination sphere, carbonaceous resource furfural 1 was introduced, which was nucleophilic treated with 1,1 Prime -dilithioferrocene 2 to form a sugar-organometallic compound: ferrocenyl monosaccharide derivative 1,1 Prime -difurfurylferrocene 3. 1,1 Prime -Difurfurylferrocene 3 can be hydrothermally treated in a microwave reactor to give 300-500 nm microspheres with the {alpha}-Fe{sub 2}O{sub 3} or Fe{sub 3}O{sub 4} nanocrystals formed on the surface, which may be favorable for new magnetic materials preparation or instead of iron with other metal ions, versatile carbon/metal composites will be possibly synthesized for catalysis, drug delivery and magnetic uses.

  11. Synthesis of a reactive polymethacrylate capillary monolith and its use as a starting material for the preparation of a stationary phase for hydrophilic interaction chromatography.

    Science.gov (United States)

    Kip, Çiğdem; Erkakan, Damla; Gökaltun, Aslıhan; Çelebi, Bekir; Tuncel, Ali

    2015-05-29

    Poly(3-chloro-2-hydroxypropyl methacrylate-co-ethylene dimethacrylate), poly(HPMA-Cl-co-EDMA) capillary monolith was proposed as a reactive starting material with tailoring flexibility for the preparation of monolithic stationary phases. The reactive capillary monolith was synthesized by free radical copolymerization of 3-chloro-2-hydroxypropyl methacrylate (HPMA-Cl) and ethylene dimethacrylate (EDMA). The mean pore size, the specific surface area and the permeability of poly(HPMA-Cl-co-EDMA) monoliths were controlled by adjusting porogen/monomer volume ratio, porogen composition and polymerization temperature. The porogen/monomer volume ratio was found as the most effective factor controlling the porous properties of poly(HPMA-Cl-co-EDMA) monolith. Triethanolamine (TEA-OH) functionalized polymethacrylate monoliths were prepared by using the reactive chloropropyl group of poly(HPMA-Cl-co-EDMA) monolith via one-pot and simple post-functionalization process. Poly(HPMA-Cl-co-EDMA) monolith reacted with TEA-OH was evaluated as a stationary phase in nano-hydrophilic interaction chromatography (nano-HILIC). Nucleotides, nucleosides and benzoic acid derivatives were satisfactorily separated with the plate heights up to 20μm. TEA-OH attached-poly(HPMA-Cl-co-EDMA) monolith showed a reproducible and stable retention behaviour in nano-HILIC runs. However, a decrease in the column performance (i.e. an increase in the plate height) was observed with the increasing retention factor. Hence "retention-dependent column efficiency" behaviour was shown for HILIC mode using the chromatographic data collected with the polymer based monolith synthesized. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Synthesis, spectral, thermal and biological studies of mixed ligand complexes with newly prepared Schiff base and 1,10-phenanthroline ligands

    Science.gov (United States)

    Abd El-Halim, Hanan F.; Mohamed, Gehad G.; Khalil, Eman A. M.

    2017-10-01

    A series of mixed ligand complexes were prepared from the Schiff base (L1) as a primary ligand, prepared by condensation of oxamide and furan-2-carbaldehyde, and 1,10-phenanthroline (1,10-phen) as a secondary ligand. The Schiff base ligand and its mixed ligand chelates were characterized based on elemental analysis, IR, 1H NMR, thermal analysis, UV-Visible, mass, molar conductance, magnetic moment. X-ray diffraction, solid reflectance and ESR also have been studied. The mixed ligand complexes were found to have the formulae of [M(L1) (1,10-phen)]Clm.nH2O (M = Cr(III) and Fe(III) (m = 3) (n = 0); M = Mn(II), Cu(II) and Cd(II) (m = 2) (n = 0); and M = Co(II) (m = 2) (n = 1), Ni(II) (m = 2) (n = 2) and Zn(II) (m = 2) (n = 3)) and that the geometrical structure of the complexes were octahedral. The parameters of thermodynamic using Coats-Redfern and Horowitz-Metzger equations were calculated. The synthesized Schiff base ligand, 1,10-phenanthroline ligand and Their mixed ligand complexes were also investigated for their antibacterial and antifungal activity against bacterial species (Gram-Ve bacteria: Pseudomonas aeruginosa and Escherichia coli) and (Gram + Ve bacteria: Bacillus subtilis and Streptococcus pneumonia) and fungi (Aspergillus fumigates and Candida albicans). The anticancer activity of the new compounds had been tested against breast (MFC7) and colon (HCT-116) cell lines. The results showed high activity for the synthesized compounds.

  13. Synthesis of the expert group meetings convened as part of the substantive preparations for the International Conference on Population and Development.

    Science.gov (United States)

    1993-01-01

    As part of the preparation for the 1994 International Conference on Population and Development to be sponsored by the UN in Cairo, 6 expert groups were convened to consider 1) population growth; 2) population policies and programs; 3) population, development, and the environment; 4) migration; 5) the status of women; and 6) family planning programs, health, and family well-being. Each group included 15 experts representing a full range of relevant scientific disciplines and geographic regions. Each meeting lasted 5 days and included a substantive background paper prepared by the Population Division as well as technical papers. Each meeting concluded with the drafting of between 18 and 37 recommendations (a total of 162). The meeting on population, the environment, and development focused on the implications of current trends in population and the environment for sustained economic growth and sustainable development. The meeting on population policies and programs observed that, since 1984, there has been a growing convergence of views about population growth among the nations of the world and that the stabilization of world population as soon as possible is now an internationally recognized goal. The group on population and women identified practical steps that agencies could take to empower women in order to achieve beneficial effects on health, population trends, and development. The meeting on FP, health, and family well-being reviewed policy-oriented issues emerging from the experience of FP programs. The meeting on population growth and development reviewed trends and prospects of population growth and age structure and their consequences for global sustainability. The population distribution and migration experts appraised current trends and their interrelationship with development. In nearly all of the group meetings, common issues emerged. Concern was universally voiced for sustainable development and sustained economic growth, relevance of past experience

  14. Carbon quantum dots prepared with polyethyleneimine as both reducing agent and stabilizer for synthesis of Ag/CQDs composite for Hg{sup 2+} ions detection

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ting; Dong, Jiang Xue; Liu, Shi Gang; Li, Na; Lin, Shu Min; Fan, Yu Zhu [Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, No.2 Tiansheng Road, BeiBei District, Chongqing 400715 (China); Lei, Jing Lie [School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044 (China); Luo, Hong Qun, E-mail: luohq@swu.edu.cn [Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, No.2 Tiansheng Road, BeiBei District, Chongqing 400715 (China); Li, Nian Bing, E-mail: linb@swu.edu.cn [Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, No.2 Tiansheng Road, BeiBei District, Chongqing 400715 (China)

    2017-01-15

    Highlights: • The carbon quantum dots (CQDs) synthesized with PEI showed an extraordinary reducibility. • The Ag/CQDs composite was prepared by using CQDs as reducing and stabilizing agent. • A simple Ag/CQDs composite-based dual-signal probe was provided for Hg{sup 2+} detection. • The proposed strategy shows a potential for detecting Hg{sup 2+} in real water samples. - Abstract: A stable silver nanoparticles/carbon quantum dots (Ag/CQDs) composite was prepared by using CQDs as reducing and stabilizing agent. The CQDs synthesized with polyethyleneimine (PEI) showed an extraordinary reducibility. When Hg{sup 2+} was presented in the Ag/CQDs composite solution, a color change from yellow to colorless was observed, accompanied by a shift of surface plasmon resonance (SPR) band and decrease in absorbance of the Ag/CQDs composite. On the basis of the further studies on TEM, XPS and XRD analysis, the possible mechanism is attributed to the formation of a silver-mercury amalgam. Hence, a two dimensional sensing platform for Hg{sup 2+} detection was constructed upon the Ag/CQDs composite. Based on the change of absorbance, a good linear relationship was obtained from 0.5 to 50 μM for Hg{sup 2+}. And the limit of detection for Hg{sup 2+} was as low as 85 nM, representing high sensitivity to Hg{sup 2+}. More importantly, the proposed method also exhibits a good selectivity toward Hg{sup 2+} over other metal ions. Besides, this strategy demonstrates practicability for the detection of Hg{sup 2+} in real water samples with satisfactory results.

  15. 40 CFR 90.316 - Hydrocarbon analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Hydrocarbon analyzer calibration. 90... Equipment Provisions § 90.316 Hydrocarbon analyzer calibration. (a) Calibrate the FID and HFID hydrocarbon... thereafter, adjust the FID and HFID hydrocarbon analyzer for optimum hydrocarbon response as specified in...

  16. 40 CFR 89.319 - Hydrocarbon analyzer calibration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Hydrocarbon analyzer calibration. 89... Equipment Provisions § 89.319 Hydrocarbon analyzer calibration. (a) The FID hydrocarbon analyzer shall... and at least annually thereafter, adjust the FID hydrocarbon analyzer for optimum hydrocarbon response...

  17. Synthesis, Characterization and Catalytic Performance of H3SiW12O40/SiO2 Prepared by Sol-Gel Technique

    Directory of Open Access Journals (Sweden)

    W. N. R. W. Isahak

    2011-01-01

    Full Text Available The purpose of this work is to study the synthesis, characterization, and catalytic performance of two types of solid heteropoly acid catalysts, namely, silicotungstic acid bulk (STAB and STA-silica sol-gel (STA-SG compared with sulfuric acid. From the XPS analyses, there was a significant formation of W-O-Si, W-O-W, and Si-O-Si bonding in STA-SG compared to that in STAB. The main spectra of O1s (90.74%, 531.5 eV followed by other O1s peak (9.26%, 532.8 eV were due to the presence of W-O-W and W-O-Si bonds, respectively. The STA-SG catalyst was found to be the more environmentally benign solid acid catalyst for the esterification reaction between oleic acid and glycerol due to its lower toxicity supported by silica via sol-gel technique. In addition, the ease of separation for STA-SG catalyst was attributed to its insoluble state in the product phase. The esterification products were then analysed by FTIR and HPLC. Both the H2SO4 and the STAB gave high conversion of 100% and 98% but at a lower selectivity of GME with 81.6% and 89.9%, respectively. On the contrary, the STA-SG enabled a conversion of 94% but with a significantly higher GME selectivity of 95%, rendering it the more efficient solid acid catalyst.

  18. Planar chiral (η6-arene)Cr(CO)3 containing carboxylic acid derivatives: synthesis and use in the preparation of organometallic analogues of the antibiotic platensimycin.

    Science.gov (United States)

    Patra, Malay; Merz, Klaus; Metzler-Nolte, Nils

    2012-01-07

    With more and more organometallic compounds receiving attention for applications in medicinal organometallic chemistry, the need arises for stereoselective syntheses of more complicated structures containing organometallic moieties, for example as isosteric substitutes for organic drug candidates. Herein, the synthesis and characterization of both diastereomers of a planar chiral (η(6)-arene)Cr(CO)(3) containing carboxylic acid derivative, namely, 3-{η(6)-(1, 2, 3, 4-tetrahydro-1-endo/exo-methyl-2-oxonaphthalen-1-yl)-tricarbonylchromium(0)}propanoic acid (7 and 8) is reported. The molecular structures of both were confirmed by single crystal X-ray diffraction. The degree of diastereoselectivity in Cr(CO)(3) complexation with methyl/tert-butyl-3-(1,2,3,4-tetrahydro-1-methyl-2-oxonaphthalen-1-yl)propanoate (4a/4b) vs. the Michael addition of methyl/tert-butyl acrylate to (η(6)-1-methyl-2-tetralone)Cr(CO)(3) (9) was also examined. In the latter case the alkylation was found to be completely diastereoselective and gave methyl/tert-butyl-3-{η(6)-(1, 2, 3, 4-tetrahydro-1-endo-methyl-2-oxonaphthalen-1-yl)-tricarbonylchromium (0)}propanoate (5a and 5b) in excellent yield. Both the carboxylic acids 7 and 8 were coupled with the aminoresorcyclic acid core to achieve diastereomeric bioorganometallics 15a and 15b based on the naturally occurring antibiotic platensimycin lead structure (1a, see Fig. 1). The newly synthesized bioorganometallics were tested against various Gram-positive and Gram-negative bacterial strains but show no promising antibacterial activity.

  19. Detection of hydrocarbons in irradiated foods

    Energy Technology Data Exchange (ETDEWEB)

    Miyahara, Makoto; Maitani, Tamio [National Inst. of Health Sciences, Tokyo (Japan); Saito, Akiko; Kamimura, Tomomi; Nagasawa, Taeko [Kitasato Univ., Sagamihara, Kanagawa (Japan). School of Allied Health Sciences; Kobayashi, Yasuo; Ito, Hitoshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Establishment

    2003-06-01

    The hydrocarbon method for the detection of irradiated foods is now recognized as the international technique. This method is based on radiolysis of fatty acids in food to give hydrocarbons. In order to expand this technique's application, ten foods (butter, cheese, chicken, pork, beef, tuna, dry shrimp, avocado, papaya, and mango) were irradiated in the range from 0.5 to 10 kGy and the hydrocarbons in them were detected. Recoveries of the hydrocarbons from most foods were acceptable (38-128%). Some hydrocarbons were found in non-irradiated foods, particularly, in butter, cheese, tuna, and shrimp. Seven irradiated foods, butter, cheese, chicken, beef, pork, tuna, dry shrimp, and avocado were detectable at their practical doses by measuring the appropriate marker hydrocarbons. In most case, marker hydrocarbon will be 1,7-hexadecadiene. However, the marker hydrocarbons produced only in irradiated foods varied from food to food; therefore, it is necessary to check a specific irradiated food for marker hydrocarbons. On the other hand, two irradiated foods (papaya and mango which were irradiated at their practical doses) were difficult to distinguish from non-irradiated foods using this method. (author)

  20. Spatial Distribution of Zeolite ZSM-5 within Catalyst Bodies Affects Selectivity and Stability of Methanol-to-Hydrocarbons Conversion

    NARCIS (Netherlands)

    Castaño, P.; Ruiz-Martinez, J.; Epelde, E.; Gayubo, A.G.; Weckhuysen, B.M.|info:eu-repo/dai/nl/285484397

    2013-01-01

    Solid acids, such as zeolites, are used as catalyst materials in a wide variety of important crude oil refinery, bulk chemical synthesis, and green processes. Examples include fluid catalytic cracking (FCC),[1] methanol-to-hydrocarbons (MTH) conversion,[ 2] plastic waste valorization,[3] and biomass

  1. Production of aromatic hydrocarbons via catalytic pyrolysis of biomass over fe-modified HZSM-5 zeolites

    Science.gov (United States)

    Iron modified HZSM-5 catalysts were prepared by partial ion exchange of NH4ZSM-5 with Fe (II) at three different loadings (1.4, 2.8 and 4.2 wt%), and their effectiveness for producing aromatic hydrocarbons from cellulose, cellobiose, lignin and switchgrass by catalytic pyrolysis were screened using ...

  2. Radiation-induced volatile hydrocarbon production in platelets. Scientific report

    Energy Technology Data Exchange (ETDEWEB)

    Radha, E.; Vaishnav, Y.N.; Kumar, K.S.; Weiss, J.F.

    1989-01-01

    Thrombocytopenia plays an important role in the development of the post-irradiation hemorrhagic syndrome. Although destruction of platelet precursors in bone marrow is a major effect of high-dose radiation exposure, the effects of radiation on preformed platelets are unclear. The latter is also of concern with respect to blood-banking practices since platelets are often irradiated at doses in the range of 20-50 Gy before transfusions to prevent graft-versus-host disease. With increasing emphasis on allogenic and autologous bone-marrow transplantation, transfusions of irradiated platelets are likely to rise. Generation of volatile hydrocarbons (ethane, pentane) as a measure of lipid peroxidation was followed in preparations from platelet-rich plasma irradiated in vitro. The hydrocarbons in the headspace of sealed vials containing irradiated and nonirradiated washed platelets, platelet-rich plasma, or platelet-poor plasma increased with time. The major hydrocarbon, pentane, increased linearly and significantly with increasing log radiation dose, suggesting that reactive oxygen species induced by ionizing radiation result in lipid peroxidation. Measurements of lipid peroxidation products may give an indication of suboptimal quality of stored and/or irradiated platelets.

  3. Hydrocarbon analysis using desorption atmospheric pressure chemical ionization

    KAUST Repository

    Jjunju, Fred Paul Mark

    2013-07-01

    Characterization of the various petroleum constituents (hydronaphthalenes, thiophenes, alkyl substituted benzenes, pyridines, fluorenes, and polycyclic aromatic hydrocarbons) was achieved under ambient conditions without sample preparation by desorption atmospheric pressure chemical ionization (DAPCI). Conditions were chosen for the DAPCI experiments to control whether ionization was by proton or electron transfer. The protonated molecule [M+H]+ and the hydride abstracted [MH]+ form were observed when using an inert gas, typically nitrogen, to direct a lightly ionized plasma generated by corona discharge onto the sample surface in air. The abundant water cluster ions generated in this experiment react with condensed-phase functionalized hydrocarbon model compounds and their mixtures at or near the sample surface. On the other hand, when naphthalene was doped into the DAPCI gas stream, its radical cation served as a charge exchange reagent, yielding molecular radical cations (M+) of the hydrocarbons. This mode of sample ionization provided mass spectra with better signal/noise ratios and without unwanted side-products. It also extended the applicability of DAPCI to petroleum constituents which could not be analyzed through proton transfer (e.g., higher molecular PAHs such as chrysene). The thermochemistry governing the individual ionization processes is discussed and a desorption/ionization mechanism is inferred. © 2012 Elsevier B.V.

  4. Aluminosilicate nanoparticles for catalytic hydrocarbon cracking.

    Science.gov (United States)

    Liu, Yu; Pinnavaia, Thomas J

    2003-03-05

    Aluminosilicate nanoparticles containing 9.0-20 nm mesopores were prepared through the use of protozeolitic nanoclusters as the inorganic precursor and starch as a porogen. The calcined, porogen-free composition containing 2 mol % aluminum exhibited the porosity, hydrothermal stability, and acidity needed for the cracking of very large hydrocarbons. In fact, the hydrothermal stability of the nanoparticles to pure steam at 800 degrees C, along with the cumene cracking activity, surpassed the analogous performance properties of ultrastable Y zeolite, the main catalyst component of commercial cracking catalysts. The remarkable hydrothermal stability and catalytic reactivity of the new nanoparticles are attributable to a unique combination of two factors, the presence of protozeolitic nanoclusters in the pore walls and the unprecedented pore wall thickness (7-15 nm). In addition, the excellent catalytic longevity of the nanoparticles is most likely facilitated by the small domain size of the nanoparticles that greatly improves access to the acid sites on the pore walls and minimizes the diffusion length of coke precursors out of the pores.

  5. Porphyrins Fused with Unactivated Polycyclic Aromatic Hydrocarbons

    KAUST Repository

    Diev, Vyacheslav V.

    2012-01-06

    A systematic study of the preparation of porphyrins with extended conjugation by meso,β-fusion with polycyclic aromatic hydrocarbons (PAHs) is reported. The meso-positions of 5,15-unsubstituted porphyrins were readily functionalized with PAHs. Ring fusion using standard Scholl reaction conditions (FeCl 3, dichloromethane) occurs for perylene-substituted porphyrins to give a porphyrin β,meso annulated with perylene rings (0.7:1 ratio of syn and anti isomers). The naphthalene, pyrene, and coronene derivatives do not react under Scholl conditions but are fused using thermal cyclodehydrogenation at high temperatures, giving mixtures of syn and anti isomers of the meso,β-fused porphyrins. For pyrenyl-substituted porphyrins, a thermal method gives synthetically acceptable yields (>30%). Absorption spectra of the fused porphyrins undergo a progressive bathochromic shift in a series of naphthyl (λ max = 730 nm), coronenyl (λ max = 780 nm), pyrenyl (λ max = 815 nm), and perylenyl (λ max = 900 nm) annulated porphyrins. Despite being conjugated with unsubstituted fused PAHs, the β,meso-fused porphyrins are more soluble and processable than the parent nonfused precursors. Pyrenyl-fused porphyrins exhibit strong fluorescence in the near-infrared (NIR) spectral region, with a progressive improvement in luminescent efficiency (up to 13% with λ max = 829 nm) with increasing degree of fusion. Fused pyrenyl-porphyrins have been used as broadband absorption donor materials in photovoltaic cells, leading to devices that show comparatively high photovoltaic efficiencies. © 2011 American Chemical Society.

  6. Synthesis and Electrochemical Evaluation of Carbon Supported Pt-Co Bimetallic Catalysts Prepared by Electroless Deposition and Modified Charge Enhanced Dry Impregnation

    Directory of Open Access Journals (Sweden)

    John Meynard M. Tengco

    2016-06-01

    Full Text Available Carbon-supported bimetallic Pt-Co cathode catalysts have been previously identified as higher activity alternatives to conventional Pt/C catalysts for fuel cells. In this work, a series of Pt-Co/C catalysts were synthesized using electroless deposition (ED of Pt on a Co/C catalyst prepared by modified charge enhanced dry impregnation. X-ray diffraction (XRD and scanning transmission electron microscopy (STEM characterization of the base catalyst showed highly dispersed particles. A basic ED bath containing PtCl62− as the Pt precursor, dimethylamine borane as reducing agent, and ethylenediamine as stabilizing agent successfully targeted deposition of Pt on Co particles. Simultaneous action of galvanic displacement and ED resulted in Pt-Co alloy formation observed in XRD and energy dispersive X-ray spectroscopy (XEDS mapping. In addition, fast deposition kinetics resulted in hollow shell Pt-Co alloy particles while particles with Pt-rich shell and Co-rich cores formed with controlled Pt deposition. Electrochemical evaluation of the Pt-Co/C catalysts showed lower active surface but much higher mass and surface activities for oxygen reduction reaction compared to a commercial Pt/C fuel cell catalyst.

  7. Enhanced coercivity in Co-doped α-Fe2O3 cubic nanocrystal assemblies prepared via a magnetic field-assisted hydrothermal synthesis

    Directory of Open Access Journals (Sweden)

    Kinjal Gandha

    2017-05-01

    Full Text Available Ferromagnetic Co-doped α-Fe2O3 cubic shaped nanocrystal assemblies (NAs with a high coercivity of 5.5 kOe have been synthesized via a magnetic field (2 kOe assisted hydrothermal process. The X-ray diffraction pattern and Raman spectra of α-Fe2O3 and Co-doped α-Fe2O3 NAs confirms the formation of single-phase α-Fe2O3 with a rhombohedral crystal structure. Electron microscopy analysis depict that the Co-doped α-Fe2O3 NAs synthesized under the influence of the magnetic field are consist of aggregated nanocrystals (∼30 nm and of average assembly size 2 μm. In contrast to the NAs synthesized with no magnetic field, the average NAs size and coercivity of the Co-doped α-Fe2O3 NAs prepared with magnetic field is increased by 1 μm and 1.4 kOe, respectively. The enhanced coercivity could be related to the well-known spin–orbit coupling strength of Co2+ cations and the redistribution of the cations. The size increment indicates that the small ferromagnetic nanocrystals assemble into cubic NAs with increased size in the magnetic field that also lead to the enhanced coercivity.

  8. Enhanced coercivity in Co-doped α-Fe2O3 cubic nanocrystal assemblies prepared via a magnetic field-assisted hydrothermal synthesis

    Science.gov (United States)

    Gandha, Kinjal; Mohapatra, Jeotikanta; Poudyal, Narayan; Elkins, Kevin; Liu, J. Ping

    2017-05-01

    Ferromagnetic Co-doped α-Fe2O3 cubic shaped nanocrystal assemblies (NAs) with a high coercivity of 5.5 kOe have been synthesized via a magnetic field (2 kOe) assisted hydrothermal process. The X-ray diffraction pattern and Raman spectra of α-Fe2O3 and Co-doped α-Fe2O3 NAs confirms the formation of single-phase α-Fe2O3 with a rhombohedral crystal structure. Electron microscopy analysis depict that the Co-doped α-Fe2O3 NAs synthesized under the influence of the magnetic field are consist of aggregated nanocrystals (˜30 nm) and of average assembly size 2 μm. In contrast to the NAs synthesized with no magnetic field, the average NAs size and coercivity of the Co-doped α-Fe2O3 NAs prepared with magnetic field is increased by 1 μm and 1.4 kOe, respectively. The enhanced coercivity could be related to the well-known spin-orbit coupling strength of Co2+ cations and the redistribution of the cations. The size increment indicates that the small ferromagnetic nanocrystals assemble into cubic NAs with increased size in the magnetic field that also lead to the enhanced coercivity.

  9. Low-temperature preparation by polymeric complex solution synthesis of Cu-Gd-doped ceria cermets for solid oxide fuel cells anodes: Sinterability, microstructures and electrical properties

    Energy Technology Data Exchange (ETDEWEB)

    Tartaj, J.; Moure, A. [Instituto de Ceramica y Vidrio (CSIC), Electroceramics Department, Kelsen 5, 28049 Madrid (Spain); Gil, V. [Instituto de Ciencia de Materiales de Aragon, Universidad de Zaragoza-CSIC, Pedro Cerbuna 12, E-50009 Zaragoza (Spain)

    2010-05-01

    A homogeneous dispersion of fine CuO in a gadolinia-doped ceria (CGO) ceramic matrix by the polymeric organic complex solution method has been achieved. Highly sinterable powders were prepared by this method after calcining the precursor at 600 C and attrition milled. The powders consist of individual particles of few tens of nanometer in size with a low agglomeration state. The isopressed compacts were sintered in air at 1000 C and reducing in N{sub 2} 90%-H{sub 2} 10% atmosphere to form Cu-CGO cermets. The microstructures showed a uniform distribution of porous metallic Cu particles surrounded by microporous spaces. The influence of Cu content in Cu-CGO cermets on the electrode performance has been investigated in order to create the most suitable microstructure. The electrical properties of Cu-CGO cermets have been also studied using impedance spectroscopy, in the temperature range form 150 to about 700 C in argon atmosphere. These measurements determined a high value of electrical conductivity at 700 C, similar to that corresponded to pure metallic cupper. (author)

  10. Temperature effects during Ostwald ripening on structural and bandgap properties of TiO{sub 2} nanoparticles prepared by sonochemical synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Reyes, L., E-mail: lgr@correo.azc.uam.mx [Instituto de Ciencia y Tecnologia del Distrito Federal, ICyTDF. Republica de Chile 6, Centro 06010, Mexico D.F. (Mexico); Universidad Autonoma Metropolitana-A, Departamento de Ciencias Basicas, Av. Sn. Pablo No. 180, Mexico 02200 D.F. (Mexico); Hernandez-Perez, I., E-mail: ihp@correo.azc.uam.mx [Universidad Autonoma Metropolitana-A, Departamento de Ciencias Basicas, Av. Sn. Pablo No. 180, Mexico 02200 D.F. (Mexico); Diaz-Barriga Arceo, L.; Dorantes-Rosales, H.; Arce-Estrada, E. [Instituto Politecnico Nacional, Departamento de Ingenieria Metalurgica y Materiales, ESIQIE-UPALM, Mexico 07738 D.F. (Mexico); Suarez-Parra, R. [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico. Priv. Xochicalco s/n, Col. Centro, Temixco, Morelos 62580 (Mexico); Cruz-Rivera, J.J. [Instituto de Metalurgia-Facultad de Ingenieria, UASLP, San Luis Potosi (Mexico)

    2010-11-15

    Anatase TiO{sub 2} nanocrystalline (6 nm) with BET specific surface area of 300 m{sup 2}/g and direct bandgap of 3.31 eV were prepared sonochemically and then it was subjected to thermal treatment from 400 to 900 deg. C for 2 h, in order to produce variable anatase-rutile ratio. Three stages were considered in the samples thermally treated: (i) anatase grains coarsening as a result of heat treatment temperature increasing the structural homogeneity and crystallinity and both phenomena produce a reduction in the specific surface area, (ii) coexistence of two phases (anatase and rutile) separated by a transition region, called an interface, and (iii) process where the rutile grains evolve into a new equilibrium shape without the presence of anatase phase, minimizing the total surface and the grain boundary energies, by mass transport diffusion. In this last stage the rutile phase has the sole function of growth and densification. The structure evolution, morphology and microstructure characteristics were obtained by X-ray diffraction (XRD) and transmission electron microscopy (TEM). All the stages of phase transformation are subject to thermal effects that stem from the redistribution of energy in the system. The UV-vis absorption spectra show that direct and indirect transitions can take place in the same sample simultaneously. This is attributed to the combined effect of samples with variable anatase-rutile ratio and particle size effect.

  11. Synthesis and Properties of Trehalose-Based Flexible Polymers Prepared from Difurfurylidene Trehalose and Maleimide- Terminated Oligo(dimethylsiloxane) by Diels-Alder Reactions

    Science.gov (United States)

    Teramoto, Naozumi; Niwa, Masashi; Shibata, Mitsuhiro

    2010-01-01

    Difurfurylidene trehalose (DFTreh) was synthesized from trehalose and furfural by an acetalization reaction. Maleimide-terminated dimethylsiloxane oligomers (DMS-BMI) were synthesized from amine-terminated dimethylsiloxane oligomers by condensation with maleic anhydride. Three types of DMS-BMI with different length were prepared. Trehalose-based polymers were synthesized by Diels-Alder reaction of DFTreh and DMS-BMI. The reaction proceeded at 40~70 °C to produce a polymer with a maximum weight average molecular weight of ~19,000. The thermal degradation temperature increased with the increase of the length of the oligo(dimethylsiloxane) units. The differential scanning calorimetry (DSC) measurements revealed the glass transition temperature (Tg) of the polymer at -130~-120 °C, and no distinct Tg not observed above room temperature in the DSC measurement. The polymer products are not liquid at room temperature, and solid films can be obtained by casting from solution, implying a phase-separated structure made up of soft and hard segments. The phase-separated structure was confirmed by transmission electron microscope (TEM) study. The DSC curve of the polymer showed a broad endothermic peak at 110~160 °C, suggesting that a retro-Diels-Alder reaction occurred. When a N,N-dimethylformamide solution of the polymer was kept at 100 °C and the resulting solution was analyzed by gel permeation chromatography (GPC), the molecular weight decreased and monomers appeared.

  12. Fluorous Analogue of Chloramine-T: Preparation, X-ray Structure Determination, and Use as an Oxidant for Radioiodination and s-Tetrazine Synthesis.

    Science.gov (United States)

    Dzandzi, James P K; Beckford Vera, Denis R; Genady, Afaf R; Albu, Silvia A; Eltringham-Smith, Louise J; Capretta, Alfredo; Sheffield, William P; Valliant, John F

    2015-07-17

    A fluorous oxidant that can be used to introduce radioiodine into small molecules and proteins and generate iodinated tetrazines for bioorthogonal chemistry has been developed. The oxidant was prepared in 87% overall yield by combining a fluorous amine with tosyl chloride, followed by chlorination using aqueous sodium hypochlorite. A crystal structure of the oxidant, which is a fluorous analogue of chloramine-T, was obtained. The compound was shown to be stable for 7 days in EtOH and for longer than three months as a solid. The oxidant was effective at promoting the labeling of arylstannanes using [(125)I]NaI, where products were isolated in high specific activity in yields ranging from 46% to 86%. Similarly, iodinated biologically active proteins (e.g., thrombin) were successfully produced, as well as a radioiodinated tetrazine, through a concomitant oxidation-halodemetalation reaction. Because of its fluorous nature, unreacted oxidant and associated reaction byproducts can be removed quantitatively from reaction mixtures by passing solutions through fluorous solid phase extraction cartridges. This feature enables rapid and facile purification, which is critical when working with radionuclides and is similarly beneficial for general synthetic applications.

  13. TiO2/SiO2 prepared via facile sol-gel method as an ideal support for green synthesis of Ag nanoparticles using Oenothera biennis extract and their excellent catalytic performance in the reduction of 4-nitrophenol

    Directory of Open Access Journals (Sweden)

    Bahar Khodadadi

    2017-01-01

    Full Text Available In the present study, the extract of the plant of Oenothera biennis was used to green synthesis of silver nanoparticles (Ag NPs as an environmentally friendly, simple and low cost method. And Additionally, TiO2/SiO2 was prepared via facile sol-gel method using starch as an important, naturally abundant organic polymer as an ideal support. The Ag NPs/TiO2/SiO2 as an effective catalyst was prepared through reduction of Ag+ ions using Oenothera biennis extract as the reducing and stabilizing agent and Ag NPs immobilization on TiO2/SiO2 surface in the absence of any stabilizer or surfactant. Several techniques such as FT-IR spectroscopy, UV-Vis spectroscopy, X-ray Diffraction (XRD, sScanning eElectron mMicroscopy (FE-SEM, Eenergy dDispersive X-ray sSpectroscopy (EDS, and Ttransmission Eelectron Mmicroscopy (TEM were used to characterize TiO2/SiO2, silver nanoparticles (Ag NPs, and Ag NPs/TiO2/SiO2. Moreover, the catalytic activity of the Ag NPs/ TiO2/SiO2 was investigated in the reduction of 4-nitrophenol (4-NP at room temperature. On the basis of the results, the Ag NPs/TiO2/SiO2 was found to be high catalytic activity highly active catalyst according to the experimental results in this study. In addition, Ag NPs/TiO2/SiO2 can be recovered and reused several times in the reduction of 4-NP with no significant loss of catalytic activity.

  14. PRACTICAL PREPARATION OF RESVERATROL 3-O-β-D-GLUCURONIDE

    OpenAIRE

    Jungong, Christian S.; Novikov, Alexei V.

    2012-01-01

    A practical synthesis of resveratrol 3-O-β-D-glucuronide, suitable for preparation of large quantities, was developed using selective deacetylation of resveratrol triacetate with ammonium acetate. A simplified procedure for large scale preparation of resveratrol is also reported.

  15. Synthesis of hydrocarbons in the earth's crust

    Energy Technology Data Exchange (ETDEWEB)

    Vanderborgh, N.E.

    1981-11-01

    This report suggests an alternative theory for the generation and migration of petroleums. Considerable evidence supports the conclusion that life processes persist deep within terrestrial and marine environments. Such in vivo processes may survive in photon-free ecologies using mechanisms that both reduce carbon dioxide and oxidize sulfides. These in vivo conversions create petroleums.

  16. 40 CFR 52.1877 - Control strategy: Photochemical oxidants (hydrocarbons).

    Science.gov (United States)

    2010-07-01

    ... oxidants (hydrocarbons). 52.1877 Section 52.1877 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY....1877 Control strategy: Photochemical oxidants (hydrocarbons). (a) The requirements of Subpart G of this... national standard for photochemical oxidants (hydrocarbons) in the Metropolitan Cincinnati interstate...

  17. Synthesis, characterization and optical properties of ATiO{sub 3}–Pr thin films prepared by a photochemical method (where A = Ba and Ca)

    Energy Technology Data Exchange (ETDEWEB)

    Cabello, G., E-mail: gerardocabelloguzman@hotmail.com [Departamento de Ciencias Básicas, Facultad de Ciencias, Universidad del Bío-Bío, Chillán (Chile); Lillo, L.; Caro, C.; Seguel, M. [Departamento de Ciencias Básicas, Facultad de Ciencias, Universidad del Bío-Bío, Chillán (Chile); Buono-Core, G.E.; Huentupil, Y. [Instituto de Química, Pontificia Universidad Católica de Valparaíso, Valparaíso (Chile); Chornik, B. [Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago 8370415 (Chile); Carrasco, C.; Rodríguez, C.A. [Departamento de Ingeniería de Materiales, Facultad de Ingeniería, Universidad de Concepción, Edmundo Larenas 270, Concepción (Chile)

    2015-10-15

    Highlights: • A method of photochemical deposition has been used to the preparation of (Ba,Ca)TiO{sub 3} thin films doped Pr(III). • The (Ba,Ca)TiO{sub 3}/Pr(III) films under 375 nm excitation shows emissions attributable to {sup 1}D{sub 2} → {sup 3}H{sub 4} transition of Pr ion. • These PL signals decreased above 10 mol% of Pr(III). • Analysis suggests the presence of intermediate energy levels in the band gap influences in the PL processes. - Abstract: This article reports the characterization and optical properties of (Ba,Ca)TiO{sub 3} thin films doped with Pr at different proportions (0–15 mol%). The films were deposited on Si (1 0 0) and quartz substrates using a photochemical method and post-annealed at 900 °C. The evaluation of photo-reactivity of the precursor complexes was monitored by UV–vis and FT-IR spectroscopy. The obtained films were characterized by X-ray diffraction and X-ray photoelectron spectroscopy. The results indicate that Ba, Ca, Ti, O and Pr are present in the form of perovskite. Under UV light excitation (375 nm) the (Ba,Ca)TiO{sub 3}–Pr films show the characteristic emissions ascribed to {sup 1}D{sub 2} → {sup 3}H{sub 4} transition of Pr{sup 3+} ion. The optical measurements show the presence of intermediate energy levels in the band gap which influence the emission processes.

  18. Preparation and characterization of calcium oxide from crab shells (Portunus pelagicus and its application in biodiesel synthesis of waste cooking oil, palm and coconut oil

    Directory of Open Access Journals (Sweden)

    Minaria Minaria

    2016-10-01

    Full Text Available Preparation of calcium oxide from Portunus pelagicus through thermal decomposition for 3 hours at various temperature 700°C, 800°C,900°C,1000°C, and 1100°C. The calcium oxidefrom decomposition was carried out and characterized by X-Ray Diffractometer (XRD, FT-IR spectrophotometer and SEM-EDX analyses. The result of XRD show decomposition Portunus pelagicus at 1000°C have diffraction pattern agree with the CaO diffraction standard with 2θ value  32.4º, 37.5º, 64.3º, and 67,5º. The FT-IR spectrum show vibration of CaO at wavenumber 354.9 cm-1. SEM-EDX data indicated the surface morphology  calcium oxide of Portunus pelagicus more homogen than Portunus pelagicus before decomposition. The decomposition of CaO at 1000°C was applied in the syntesis of biodiesel from waste cooking oil, palm oil, and coconut oil. The biodiesel products  have density  0.8621, 0.8725, and 0.8688 g/cm3. Viscosity are 5.27, 3.71, and 2.45 mm2/s(cst. Acid values respectively are 0.3069, 0.2423 and 0.2100 mg/KOH and Iodine numbers 39.48, 36.12 and 9.24 g I2/100g. All characteristic of biodiesel from waste cooking oil, palm oil, and coconut oil are agree with SNI standard.  The best biodiesel product derived from coconut oil is agree to the parameter value of biodiesel standard.  Keywords: biodiesel. Portunus pelagicus. calcium oxide. catalyst.

  19. Synthesis and Photoluminescent Properties of Nanorod Bundle Ln4O(OH)9NO3:Eu(Ln = Y, Lu) Prepared by Hydrothermal Method.

    Science.gov (United States)

    Li, Ling; Noh, Hyeon Mi; Liu, Xiaoguang; Moon, Byung Kee; Choi, Byung Chun; Jeong, Jung Hyun

    2015-07-01

    Well-crystallized nanorod bundles Ln4O(OH)9NO3:1%Eu(Ln = Y, Lu) have been successfully prepared by hydrothermal method. The crystalline phase, size and optical properties were characterized using powder X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), infrared (IR) spectrograph and photoluminescent (PL) spectra. Site occupations of Eu3+ in crystals Ln4O(OH)9NO3:Eu(Ln = Y, Lu) were discussed based on excitation spectra and the empirical relationship formula between the charge transfer (CT) energy and the environmental factor. The emission spectra exhibited that the strongest emission peaks with an excitation wavelength of 395 nm were at 617 and 626 nm in crystal Lu4O(OH)9NO3:1%Eu and Y4O(OH)9NO3:1%Eu, respectively, both of which come from 5D0-7F2 transition of the Eu3+ ions. The broad excitation peaks at about 254 and 255 nm were found when monitored at 617 and 628 nm in crystal Lu4O(OH)9NO3:1%Eu and Y4O(OH)9NO3:1%Eu, respectively, which were due to O-Eu CT transition. Based on the dielectric theory of complex crystal, the CT bands at about 254 and 255 nm in Ln4O(OH)9NO3:1%Eu(Ln = Y, Lu) were assigned to the transition of O-Eu at Ln3(Ln = Y, Lu) site, from which we can conclude that Eu3+ ions occupied the site of Ln3(Ln = Y, Lu) in crystal Ln4O(OH)9NO3:1%Eu(Ln = Y, Lu). It put forward a new route to investigate site occupation of luminescent center ions in rare earth doped complex inorganic luminescence materials.

  20. Phenoxo bridged dinuclear Zn(II) Schiff base complex as new precursor for preparation zinc oxide nanoparticles: Synthesis, characterization, crystal structures and photoluminescence studies

    Energy Technology Data Exchange (ETDEWEB)

    Saeednia, S., E-mail: sami_saeednia@yahoo.com [Department of Chemistry, Faculty of Science, Vali-e-Asr University of Rafsanjan, Rafsanjan 77188-97111 (Iran, Islamic Republic of); Iranmanesh, P. [Department of physics, Faculty of Science, Vali-e-Asr University of Rafsanjan, Rafsanjan 77188-97111 (Iran, Islamic Republic of); Ardakani, M. Hatefi; Mohammadi, M.; Norouzi, Gh. [Department of Chemistry, Faculty of Science, Vali-e-Asr University of Rafsanjan, Rafsanjan 77188-97111 (Iran, Islamic Republic of)

    2016-06-15

    Highlights: • A novel nano-scale Zn(II) complex was synthesized by solvothermal method. • Chemical structure of the nanostructures was characterized as well as bulk complex. • The photoluminescence property of the complex was investigated at room temperature. • The thermogravimetry and differential thermal analysis were carried out. • Thermal decomposition of the nanostructures was prepared zinc oxide nanoparticles. - Abstract: Nanoparticles of a novel Zn(II) Schiff base complex, [Zn(HL)NO{sub 3}]{sub 2} (1), (H{sub 2}L = 2-[(2-hydroxy-propylimino) methyl] phenol), was synthesized by using solvothermal method. Shape, morphology and chemical structure of the synthesized nanoparticles were characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), Fourier Transform Infrared Spectoscopy (FT-IR) and UV–vis spectroscopy. Structural determination of compound 1 was determined by single-crystal X-ray diffraction. The results were revealed that the zinc complex is a centrosymmetric dimer in which deprotonated phenolates bridge the two five-coordinate metal atoms and link the two halves of the dimer. The thermal stability of compound 1 was analyzed by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The effect of the initial substrates concentration and reaction time on size and morphology of compound 1 nanostructure was investigated as well. Furthermore, the luminescent properties of the complex 1 were examined. ZnO nanoparticles with diameter between 15 and 20 nm were simply synthesized by solid-state transformation of compound 1 at 700 °C.

  1. Microstructures and mechanical properties of large-scale Al IIO 3/ZrO II(Y IIO 3) self-growing ceramic plates prepared by combustion synthesis under high gravity

    Science.gov (United States)

    Zhao, Zhongmin; Zhang, Long; Zhang, Shiyue; Pan, Chuanzeng; Zhang, Jing; Song, Yalin; Zhu, Hao

    2007-07-01

    By introducing ZrO II and Y IIO 3 mixed powder into the thermit, the large-scale Al IIO 3/ZrO II (Y IIO 3) self-growing ceramic plates were prepared from the melts through combustion synthesis under high gravity. The materials were mainly formed by randomly-orientated rod-shaped colonies with faceted structures consisting of a triangular dispersion of orderly nano-submicron ZrO II fibers in the Al IIO 3 matrix, surrounded by the boundary regions that contained the coarse irregular-shaped ZrO II and Al IIO 3 phases. The flexural strength of the self-growing ceramic plate was excellent (measured 1278MPa), and it was not only attributed to the small critical defect size caused by the fine eutectic microstructures, excellent bonding between the Al IIO 3/ZrO II phases and the thin inter-colony regions, but also more importantly dependent on high fracture toughness of 13.7 MPaÂ.m 1/2, which is controlled by residual compressive stress toughening in the colonies, transformation induced toughening and transformation induced microcrack toughening mechanisms in inter-colony regions during crack propagation.

  2. Preparation and Application of MnO2 Nanoparticles/Zeolite AgY Composite Catalyst by Confined Space Synthesis (CSS Method for the Desulfurization and Elimination of SP and OPP

    Directory of Open Access Journals (Sweden)

    M. Sadeghi

    2012-12-01

    Full Text Available In this work, zeolite NaY was prepared by hydrothermal method. Then, silver ions were replaced in the zeolite NaY with silver nitrate (AgNO3 solution via using ion exchange (IE method. The Manganese dioxide (MnO2 nanoparticles (9.3 and 15.8 wt % for guest were deposited in the zeolite AgY(host structure with Mn(NO32 aqueous and KMnO4 solutions by confined space synthesis (CSS method. Synthesized samples were studied and characterized via XRD, SEM/EDAX, FTIR, AAS and N2-BET techniques. The desulfurization  and  elimination  reaction of 2- chloroethyl phenyl sulfide (2-CEPS and DEPPT (O, S-diethyl phenyl phosphonothioate have been investigated by 15.8 wt% Nano MnO2/Zeolite AgY composite and MnO2  nanoparticles catalysts and via GC, GC-MS and 31 PNMR.

  3. Palladium-zinc catalysts on mesoporous titania prepared by colloid synthesis. II. Synthesis and characterization of PdZn/TiO2 coating on inner surface of fused silica capillary

    Science.gov (United States)

    Okhlopkova, Lyudmila B.; Kerzhentsev, Michail A.; Tuzikov, Fedor V.; Larichev, Yurii V.; Ismagilov, Zinfer R.

    2012-09-01

    Nanoparticle-doped mesoporous titania coating was synthesized by incorporation of PdZn nanoparticles into TiO2 sol followed by dip coating of the sol on inner surface of fused silica capillary. Monodispersed PdZn bimetallic colloidal particles with average particle diameters of approximately 2 nm have been prepared by an ethylene glycol reduction of ZnCl2 and Pd(CH3COO)2 in the presence of polyvinylpyrrolidone. The textural properties, surface structure, chemical composition, and morphology of the samples were investigated by means of N2 sorption measurements, TEM, and X-ray diffraction. PdZn/TiO2 coating has been further analyzed by quantitative analysis of the SAXS data in combination with the density contrast method, providing direct structural-dispersion information about the active component and support. Calcination conditions suitable for surfactant removal have been optimized to obtain PdZn/TiO2 coatings with required metal particle size and composition. The high dispersion and chemical composition of the nanoparticles embedded in mesoporous titania coating have been retained with no modification after thermal treatment in vacuum at 300 °C. Results suggest how porous structure of the PdZn coating may be fine-tuned to improve the accessibility of the pores to reactants. The control of the pore size in the range of 4.9-6.8 nm of the mesoporous titania was achieved by adding co-surfactants, such as n-butanol.

  4. Versatility of hydrocarbon production in cyanobacteria.

    Science.gov (United States)

    Xie, Min; Wang, Weihua; Zhang, Weiwen; Chen, Lei; Lu, Xuefeng

    2017-02-01

    Cyanobacteria are photosynthetic microorganisms using solar energy, H2O, and CO2 as the primary inputs. Compared to plants and eukaryotic microalgae, cyanobacteria are easier to be genetically engineered and possess higher growth rate. Extensive genomic information and well-established genetic platform make cyanobacteria good candidates to build efficient biosynthetic pathways for biofuels and chemicals by genetic engineering. Hydrocarbons are a family of compounds consisting entirely of hydrogen and carbon. Structural diversity of the hydrocarbon family is enabled by variation in chain length, degree of saturation, and rearrangements of the carbon skeleton. The diversified hydrocarbons can be used as valuable chemicals in the field of food, fuels, pharmaceuticals, nutrition, and cosmetics. Hydrocarbon biosynthesis is ubiquitous in bacteria, yeasts, fungi, plants, and insects. A wide variety of pathways for the hydrocarbon biosynthesis have been identified in recent years. Cyanobacteria may be superior chassis for hydrocabon production in a photosynthetic manner. A diversity of hydrocarbons including ethylene, alkanes, alkenes, and terpenes can be produced by cyanobacteria. Metabolic engineering and synthetic biology strategies can be employed to improve hydrocarbon production in cyanobacteria. This review mainly summarizes versatility and perspectives of hydrocarbon production in cyanobacteria.

  5. short communication aliphatic and polycyclic aromatic hydrocarbons ...

    African Journals Online (AJOL)

    Preferred Customer

    The compositional pattern of the photo-modified bitumen samples suggests that there was initial cracking of large molecular mass hydrocarbons in the bitumen, followed by recombination after long periods of exposure to sunlight. The polycyclic aromatic hydrocarbon profile of the Agbabu natural bitumen as a function of.

  6. Palynofacies characterization for hydrocarbon source rock ...

    Indian Academy of Sciences (India)

    This paper deals with the hydrocarbon source rock evaluation of the Subathu Formation exposed at Marhighat on Sarahan–Narag road in Sirmaur district of Himachal Pradesh. Hydrocarbon potential of these sediments is estimated on the basis of palynofacies analysis and thermal alteration index (TAI) values based on the ...

  7. Detection and quantification of hydrocarbons in sediments

    Science.gov (United States)

    Wynn, Jeff; Williamson, Mike; Frank, Jeff

    2016-01-01

    A new technology developed by the US Geological Survey now allows for fast, direct detection of hydrocarbon plumes both in rivers and drifting in the deep ocean. Recent experiments show that the method can also detect and quantify hydrocarbons buried in river sediments and estuaries. This approach uses a variant of induced polarization, a surface-sensitive physical property of certain polarizable materials immersed in an electrolyte that can accept and adsorb charge under an inducing voltage. Known polarizable materials include most sulfides, ilmenite (FeTiO3), metallic objects such as buried wrecks and pipelines, and now hydrocarbons. The hydrocarbon-in-water response to induced polarization is in fact nearly two orders of magnitude greater than the IP response of any of the hard minerals. The oil:water detection limit for hydrocarbons so far is down to 0.0002% in the laboratory.

  8. Synthesis, sintering and dissolution of thorium and uranium (IV) mixed oxide solid solutions: influence of the method of precursor preparation; Synthese, frittage et caracterisation de solutions solides d'oxydes mixtes de thorium et d'uranium (IV): influence de la methode de preparation du precurseur

    Energy Technology Data Exchange (ETDEWEB)

    Hingant, N

    2008-12-15

    Mixed actinide dioxides are currently considered as potential fuels for the third and fourth generations of nuclear reactors. In this context, thorium-uranium (IV) dioxide solid solutions were studied as model compounds to underline the influence of the method of preparation on their physico-chemical properties. Two methods of synthesis, both based on the initial precipitation of oxalate precursors have been developed. The first consisted in the direct precipitation ('open' system) while the second involved hydrothermal conditions ('closed' system). The second method led to a significant improvement in the crystallization of the samples especially in the field of the increase of the grain size. In these conditions, the formation of a complete solid solution Th{sub 1-x}U{sub x}(C{sub 2}O{sub 4}){sub 2}.2H{sub 2}O was prepared between both end-members. Its crystal structure was also resolved. Whatever the initial method considered, these compounds led to the final dioxides after heating above 400 C. The various steps associated to this transformation, involving the dehydration of precursors then the decomposition of oxalate groups have been clarified. Moreover, the use of wet chemistry methods allowed to reduce the sintering temperature of the final thorium-uranium (IV) dioxide solid solutions. Whatever the method of preparation considered, dense samples (95% to 97% of the calculated value) were obtained after only 3 hours of heating at 1500 C. Additionally, the use of hydrothermal conditions significantly increased the grain size, leading to the reduction of the occurrence of the grain boundaries and of the global residual porosity. The significant improvement in the homogeneity of cations distribution in the samples was also highlighted. Finally, the chemical durability of thorium-uranium (IV) dioxide solid solutions was evaluated through the development of leaching tests in nitric acid. The optimized homogeneity especially in terms of the

  9. GROUPS IN PEPTIDE SYNTHESIS

    African Journals Online (AJOL)

    carboxamide protecting group in peptide synthesis. RESULTS AND DISCUSSION l-Tetralinylamines used as precursors to prepare the carboxamide derivatives of asparagine and glutamine are shown in Table 1: Table 1. Summary of l-tetralinyl amines. Amines Aromatic ring NHZ. X Y Z Z. 1 H H H. 2 OCH; H H. 3 H OCH ...

  10. Study of hydrocarbon--shale interaction. Progress report No. 1, July 1, 1976--October 1, 1976

    Energy Technology Data Exchange (ETDEWEB)

    Schettler, P.D. Jr.

    1976-01-01

    Work on Hydrocarbon-Shale Interaction at Juniata College from June 1, 1976 through September 30, 1976 is summarized. Work was accomplished in the following areas: constrictive and geometric effects associated with gas production from shale wells, diffusion constants, hydrocarbon gas analysis, adsorption isotherms and powder x-ray diffraction. A bibliography on adsorption and diffusion in shale was prepared and is included. A detailed description of the procedures used in construction and calibration of the apparatus used for sorption measurements is included. All experimental work was done on cores from Well No. 20403 in Lincoln County, West Virginia.

  11. Nanoscale intimacy in bifunctional catalysts for selective conversion of hydrocarbons

    Science.gov (United States)

    Zecevic, Jovana; Vanbutsele, Gina; de Jong, Krijn P.; Martens, Johan A.

    2015-12-01

    The ability to control nanoscale features precisely is increasingly being exploited to develop and improve monofunctional catalysts. Striking effects might also be expected in the case of bifunctional catalysts, which are important in the hydrocracking of fossil and renewable hydrocarbon sources to provide high-quality diesel fuel. Such bifunctional hydrocracking catalysts contain metal sites and acid sites, and for more than 50 years the so-called intimacy criterion has dictated the maximum distance between the two types of site, beyond which catalytic activity decreases. A lack of synthesis and material-characterization methods with nanometre precision has long prevented in-depth exploration of the intimacy criterion, which has often been interpreted simply as ‘the closer the better’ for positioning metal and acid sites. Here we show for a bifunctional catalyst—comprising an intimate mixture of zeolite Y and alumina binder, and with platinum metal controllably deposited on either the zeolite or the binder—that closest proximity between metal and zeolite acid sites can be detrimental. Specifically, the selectivity when cracking large hydrocarbon feedstock molecules for high-quality diesel production is optimized with the catalyst that contains platinum on the binder, that is, with a nanoscale rather than closest intimacy of the metal and acid sites. Thus, cracking of the large and complex hydrocarbon molecules that are typically derived from alternative sources, such as gas-to-liquid technology, vegetable oil or algal oil, should benefit especially from bifunctional catalysts that avoid locating platinum on the zeolite (the traditionally assumed optimal location). More generally, we anticipate that the ability demonstrated here to spatially organize different active sites at the nanoscale will benefit the further development and optimization of the emerging generation of multifunctional catalysts.

  12. Photodynamic activity of polycyclic hydrocarbon

    Energy Technology Data Exchange (ETDEWEB)

    Epstein, S.S.

    1963-01-01

    Exposure of Paramecium caudatum to suspensions of 3,4-benzopyrene, followed by long wave ultraviolet irradiation, results in cell death at times related, inter alia, to carcinogen concentration. Prior to death, the cells exhibit progressive immobilization and blebbing. This photodynamic response is a sensitized photo-oxidation, as it is oxygen-dependent and inhibited by anti-oxidants, such as butylated hydroxy anisole and ..cap alpha..-tocopherol. Protection is also afforded by other agents, including Tweens, tryptophan and certain fractions of plasma proteins. No evidence was found for the involvement of peroxides or sulfhydryl groups. The correlations between photodynamic toxicity and carcinogenicity in a large series of polycyclic hydrocarbons is under investigation. Assays of air extracts for photodynamic toxicity are in progress. Significant toxicity has been found in oxygenated besides aromatic fractions.

  13. Pyrochlore-type catalysts for the reforming of hydrocarbon fuels

    Science.gov (United States)

    Berry, David A [Morgantown, WV; Shekhawat, Dushyant [Morgantown, WV; Haynes, Daniel [Morgantown, WV; Smith, Mark [Morgantown, WV; Spivey, James J [Baton Rouge, LA

    2012-03-13

    A method of catalytically reforming a reactant gas mixture using a pyrochlore catalyst material comprised of one or more pyrochlores having the composition A.sub.2-w-xA'.sub.wA''.sub.xB.sub.2-y-zB'.sub.yB''.sub.zO.sub.7-.DELTA.. Distribution of catalytically active metals throughout the structure at the B site creates an active and well dispersed metal locked into place in the crystal structure. This greatly reduces the metal sintering that typically occurs on supported catalysts used in reforming reactions, and reduces deactivation by sulfur and carbon. Further, oxygen mobility may also be enhanced by elemental exchange of promoters at sites in the pyrochlore. The pyrochlore catalyst material may be utilized in catalytic reforming reactions for the conversion of hydrocarbon fuels into synthesis gas (H.sub.2+CO) for fuel cells, among other uses.

  14. Flame Synthesis of Single- and Multi-Walled Carbon Nanotubes and Nanofibers

    Science.gov (United States)

    VanderWal, R. L.; Ticich, Thomas M.

    2001-01-01

    Metal-catalyzed carbon nanotubes are highly sought for a diverse range of applications that include nanoelectronics, battery electrode material, catalysis, hydrogen storage media and reinforcing agents in polymer composites. These latter applications will require vast quantities of nanotubes at competitive prices to be economically feasible. Moreover, reinforcing applications may not require ultrahigh purity nanotubes. Indeed, functionalization of nanotubes to facilitate interfacial bonding within composites will naturally introduce defects into the tube walls, lessening their tensile strength. Current methods of aerosol synthesis of carbon nanotubes include laser ablation of composite targets of carbon and catalyst metal within high temperature furnaces and decomposition of a organometallics in hydrocarbons mixtures within a tube furnace. Common to each approach is the generation of particles in the presence of the reactive hydrocarbon species at elevated temperatures. In the laser-ablation approach, the situation is even more dynamic in that particles and nanotubes are borne during the transient cooling phase of the laser-induced plasma for which the temperature far exceeds that of the surrounding hot gases within the furnace process tube. A shared limitation is that more efficient methods of nanoparticle synthesis are not readily incorporated into these approaches. In contrast, combustion can quite naturally create nanomaterials such as carbon black. Flame synthesis is well known for its commercial scalability and energy efficiency. However, flames do present a complex chemical environment with steep gradients in temperature and species concentrations. Moreover, reaction times are limited within buoyant driven flows to tens of milliseconds. Therein microgravity can greatly lessen temperature and spatial gradients while allowing independent control of flame residence times. In preparation for defining the microgravity experiments, the work presented here focuses

  15. Adsorption of volatile hydrocarbons in iron polysulfide chalcogels

    KAUST Repository

    Ahmed, Ejaz

    2014-11-01

    We report the synthesis, characterization and possible applications of three new metal-chalcogenide aerogels KFe3Co3S 21, KFe3Y3S22 and KFe 3Eu3S22. Metal acetates react with the alkali metal polychalcogenides in formamide/water mixture to form extended polymeric frameworks that exhibit gelation phenomena. Amorphous aerogels obtained after supercritical CO2 drying have BET surface area from 461 to 573 m 2/g. Electron microscopy images and nitrogen adsorption measurements showed that pore sizes are found in micro (below 2 nm), meso (2-50 nm), and macro (above 50 nm) porous regions. These chalcogels possess optical bandgaps in the range of 1.55-2.70 eV. These aerogels have been studied for the adsorption of volatile hydrocarbons and gases. A much higher adsorption of toluene in comparison with cyclohexane and cyclopentane vapors have been observed. The adsorption capacities of the three volatile hydrocarbons are found in the following order: toluene > cyclohexane > cyclopentane. It has been observed that high selectivity in adsorption is feasible with high-surface-area metal chalcogenides. Similarly, almost an eight to ten times increase in adsorption selectivity towards CO2 over H2/CH4 was observed in the aerogels. Moreover, reversible ion-exchange properties for K+/Cs+ ions have also been demonstrated. © 2014 Elsevier Inc. All rights reserved.

  16. A kinetically blocked 1,14:11,12-dibenzopentacene: A persistent triplet diradical of a non-Kekulé polycyclic benzenoid hydrocarbon

    KAUST Repository

    Li, Yuan

    2014-01-01

    The synthesis of high-spin polycyclic hydrocarbons is very challenging due to their extremely high reactivity. Herein, we report the synthesis and characterization of a kinetically blocked 1,14:11,12-dibenzopentacene, DP-Mes, which represents a rare persistent triplet diradical of a non-Kekulé polycyclic benzenoid hydrocarbon. In contrast to its structural isomer 1,14:7,8-dibenzopentacene (heptazethrene) with a singlet biradical ground state, DP-Mes is a triplet diradical as confirmed by ESR and ESTN measurements and density functional theory calculations. DP-Mes also displays intermolecular antiferromagnetic spin interactions in solution at low temperature. © 2014 the Partner Organisations.

  17. A modified microbial adhesion to hydrocarbons assay to account for the presence of hydrocarbon droplets.

    Science.gov (United States)

    Zoueki, Caroline Warne; Tufenkji, Nathalie; Ghoshal, Subhasis

    2010-04-15

    The microbial adhesion to hydrocarbons (MATH) assay has been used widely to characterize microbial cell hydrophobicity and/or the extent of cell adhesion to hydrophobic liquids. The classical MATH assay involves spectrophotometric absorbance measurements of the initial and final cell concentrations in an aqueous cell suspension that has been contacted with a hydrocarbon liquid. In this study, microscopic examination of the aqueous cell suspension after contact with hexadecane or a hexadecane/toluene mixture revealed the presence of hydrocarbon droplets. The hydrocarbon droplets contributed to the absorbance values during spectrophotometric measurements and caused erroneous estimates of cell concentrations and extents of microbial adhesion. A modified MATH assay that avoids such artefacts is proposed here. In this modified assay, microscopic examination of the aqueous suspension and direct cell counts provides cell concentrations that are free of interference from hydrocarbon droplets. The presence of hydrocarbon droplets was noted in MATH assays performed with three bacterial strains, and two different hydrocarbons, at ionic strengths of 0.2 mM and 20 mM and pH 6. In these experiments, the formation of quasi-stable hydrocarbon droplets cannot be attributed to the presence of biosurfactants, or stabilization by biocolloids. The presence of surface potential at the hydrocarbon-water interface that was characterized by electrophoretic mobility of up to -1 and -2 microm cm/Vs, likely caused the formation of the quasi-stable hydrocarbon droplets that provided erroneous results using the classical MATH assay. 2010 Elsevier Inc. All rights reserved.

  18. Exploring iron-based multifunctional catalysts for Fischer-Tropsch synthesis: a review.

    Science.gov (United States)

    Abelló, Sònia; Montané, Daniel

    2011-11-18

    The continuous increase in oil prices together with an increase in carbon dioxide concentration in the atmosphere has prompted an increased interest in the production of liquid fuels from non-petroleum sources to ensure the continuation of our worldwide demands while maximizing CO(2) utilization. In this sense, the Fischer-Tropsch (FT) technology provides a feasible option to render high value-added hydrocarbons. Alternative sources, such as biomass or coal, offer a real possibility to realize these purposes by making use of H(2)-deficient or CO(2)-rich syngas feeds. The management of such feeds ideally relies on the use of iron catalysts, which exhibit the unique ability to adjust the H(2)/CO molar ratio to an optimum value for hydrocarbon synthesis through the water-gas-shift reaction. Taking advantage of the emerging attention to hybrid FT-synthesis catalysts based on cobalt and their associated benefits, an overview of the current state of literature in the field of iron-based multifunctional catalysts is presented. Of particular interest is the use of zeolites in combination with a FT catalyst in a one-stage operation, herein named multifunctional, which offer key opportunities in the modification of desired product distributions and selectivity, to eventually overcome the quality limitations of the fuels prepared under intrinsic FT conditions. This review focuses on promising research activities addressing the conversion of syngas to liquid fuels mediated by iron-based multifunctional materials, highlights their preparation and properties, and discusses their implication and challenges in the area of carbon utilization through H(2)/CO(+CO(2)) mixtures. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Preparation of Silver Nanoparticles from Synthetic and Natural Sources: Remediation Model for PAHs

    Science.gov (United States)

    Abbasi, Maryam; Saeed, Fatima; Rafique, Uzaira

    2014-06-01

    The emergence of nanoscience and technology is gaining popularity with an increasing demand for metal nanoparticles applicability in various areas such as electronics, catalysis, chemistry, energy and medicine. Metallic nanoparticles are traditionally synthesized by wet chemical techniques, where the chemicals used are quite often toxic and flammable. In this work, an attempt is made to compare the efficiency of two different synthesis methods and application of each for the remediation of poly aromatic hydrocarbons (PAHs). In this regard, silver nanoparticles are prepared by green and wet chemical method using plant extract of garlic (Allium sativum). The extract is known to reduce the metal during synthesis and acts as stabilizing ligand. These synthesized silver nanoparticles (Agp) and (AgW) were applied as adsorbents in synthetic batch mode experiments at varying parameters of pH and temperature. A concentration of 0.01mg/L of Phenanthrene, Anthracene, and Pyrene were induced at fixed dosage of 1mg/Kg of adsorbent. Residual concentration of each PAH was analyzed on UV-Visible spectrophotometer. The results indicated that both adsorbents follow the sequence of Phenanthrene>Pyrene>Anthracene with optimal removal of higher than 85% in each case. A distinguishing privilege is attained by Agp adsorbent showing 3, 3 and 11 orders of magnitude higher efficiency than Agw. It may be attributed to more functional groups in the plant extract participating in binding of PAH to the surface. Each synthesized adsorbents was characterized by FTIR, SEM and EDX. The average particle size was determined to be of the order of 13-26 nm. The study concludes the use of alternate economical and green adsorbents for control of poly aromatic hydrocarbons (PAHs).

  20. Synergetic deoxy reforming of cellulose and fatty acid esters for liquid hydrocarbon-rich oils.

    Science.gov (United States)

    Wang, Chao; Sui, Jingjing; Lu, Weipeng; Li, Baopeng; Li, Guoxing; Ding, Yihong; Huang, Yong; Geng, Jianxin

    2015-11-01

    A series of liquid hydrocarbons (alkylbenzenes, alkanes, and alkenes) were obtained by a synergetic deoxy reforming (SDR) process of cellulose and linoleic acid methyl ester (LAME) at 350°C and 4-6MPa in a closed system without external source of hydrogen. The liquid product was obtained with a yield of 15wt% at a LAME/cellulose ratio of 0.2. In contrast, the direct deoxy reforming of cellulose produces oil that contains plenty of phenols and oxygen-containing compounds. Due to the insufficiency of water employed (30wt%), a radical reaction pathway was proposed. Quantum chemical calculations indicate that the radicals from LAME interfere with the reactions of the intermediate products from cellulose, being responsible for the removal of phenols and the formation of hydrocarbons. The SDR process offers an embryonic insight in an alternative technique for preparation of hydrocarbon fuels. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Hydrocarbonization process evaluation report. Volume II. Evaluation of process feasibility. [49 refs

    Energy Technology Data Exchange (ETDEWEB)

    Holmes, J.M.; Dyslin, D.A.; Edwards, M.S.; Joy, D.S.; Peterson, G.R.

    1977-07-01

    Volume II of a two-volume study concerning the preliminary design and economic evaluation of a Hydrocarbonization Facility includes: (1) a review of the current status of the major processing units, (2) an assessment of operating problems, (3) considerations of possible process alternatives, (4) an evaluation of the overall process feasibility, and (5) recommendations for future process development. Results of the study emphasize the need for testing the evaluated process, which is based on the Clean Coke Process, in a continuous pilot plant using a wide variety of highly caking bituminous coals as feed material. A program suggested for the pilot plant would encompass: (1) development of improved methods for the prevention of agglomeration of highly caking coals during hydrocarbonization, (2) optimization of the yields of coal liquids, (3) investigation of a single-stage high-temperature hydrocarbonizer optimized for char production, and (4) optimization of beneficiation ratios employed during coal preparation.

  2. Using supercritical fluids to refine hydrocarbons

    Science.gov (United States)

    Yarbro, Stephen Lee

    2015-06-09

    A system and method for reactively refining hydrocarbons, such as heavy oils with API gravities of less than 20 degrees and bitumen-like hydrocarbons with viscosities greater than 1000 cp at standard temperature and pressure, using a selected fluid at supercritical conditions. A reaction portion of the system and method delivers lightweight, volatile hydrocarbons to an associated contacting unit which operates in mixed subcritical/supercritical or supercritical modes. Using thermal diffusion, multiphase contact, or a momentum generating pressure gradient, the contacting unit separates the reaction products into portions that are viable for use or sale without further conventional refining and hydro-processing techniques.

  3. Waste Plastic Converting into Hydrocarbon Fuel Materials

    Energy Technology Data Exchange (ETDEWEB)

    Sarker, Moinuddin; Mamunor Rashid, Mohammad; Molla, Mohammad

    2010-09-15

    The increased demand and high prices for energy sources are driving efforts to convert organic compounds into useful hydrocarbon fuels. Although much of this work has focused on biomass, there are strong benefits to deriving fuels from waste plastic material. Natural State Research Inc. (NSR) has invented a simple and economically viable process to decompose the hydrocarbon polymers of waste plastic into the shorter chain hydrocarbon of liquid fuel (patent pending). The method and principle of the production / process will be discussed. Initial tests with several widely used polymers indicate a high potential for commercialization.

  4. Biodegradation of hydrocarbons from a refinery spill

    Energy Technology Data Exchange (ETDEWEB)

    Bergueiro-Lopez, J.R.; Serra-Socias, F.; Moreno-Garcia-Luengo, S.; Morales-Correas, N.; Dominguez-Laseca, F. [Universidad de las Islas Baleares (Spain)

    1996-09-01

    The biodegradation of several crude oil wastes from an oil refinery spill, was studied. Crude oil was spilled onto soil; with time, only the higher boiling point hydrocarbons remained as residue. Samples of this highly weathered hydrocarbon mixture were suspended in water to which Finasol OSR 51 dispersant was added in order to enhance dispersion. Also, certain microorganisms and a degradation accelerator, were both added to accelerate degradation. Each compound was identified by CG/FID. Daily records were kept of the concentration of hydrocarbons, and the percent degradation. Tables showing the degradation percentages achieved by each compound of the crude left over after several days, are included. 4 refs., tabs., 1 fig.

  5. Design and Testing of a Labview- Controlled Catalytic Packed- Bed Reactor System For Production of Hydrocarbon Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Street, J.; Yu, F.; Warnock, J.; Wooten, J.; Columbus, E.; White, M. G.

    2012-05-01

    Gasified woody biomass (producer gas) was converted over a Mo/H+ZSM-5 catalyst to produce gasolinerange hydrocarbons. The effect of contaminants in the producer gas showed that key retardants in the system included ammonia and oxygen. The production of gasoline-range hydrocarbons derived from producer gas was studied and compared with gasoline-range hydrocarbon production from two control syngas mixes. Certain mole ratios of syngas mixes were introduced into the system to evaluate whether or not the heat created from the exothermic reaction could be properly controlled. Contaminant-free syngas was used to determine hydrocarbon production with similar mole values of the producer gas from the gasifier. Contaminant-free syngas was also used to test an ideal contaminant-free synthesis gas situation to mimic our particular downdraft gasifier. Producer gas was used in this study to determine the feasibility of using producer gas to create gasoline-range hydrocarbons on an industrial scale using a specific Mo/H+ZSM-5 catalyst. It was determined that after removing the ammonia, other contaminants poisoned the catalyst and retarded the hydrocarbon production process as well.

  6. Composition, microstructures and properties of Al2O3/ZrO2 (Y2O3) self-growing ceramic composites prepared by combustion synthesis under high gravity

    Science.gov (United States)

    Zhao, Z. M.; Zhang, L.; Song, Y. G.; Wang, W. G.; Liu, H. B.

    2009-03-01

    By introducing ZrO2 (4Y) powder into the thermit, Al2O3/ZrO2 (4Y) composite ceramics were prepared through combustion synthesis under high gravity, and the correlations of composition, microstructures and mechanical properties of composite ceramics were investigated. The results of XRD, SEM and EDS showed that Al2O3/33%ZrO2 (4Y) were composed of random-orientated rod-shaped colonies consisting of a triangular dispersion of orderly submicron-nanometer t-ZrO2 fibers, surrounded by inter-colony regions consisting of spherically-shaped micronmeter t-ZrO2 grains; Al2O3/45%ZrO2 (4Y) were comprised of spherically-shaped micron-meter t-ZrO2 grains, surround by irregularly-shaped α-Al2O3 grains and a few colonies. Compared to the directionally solidified Al2O3/ZrO2 (Y2O3), the increase in hardness and flexural strength of Al2O3/33%ZrO2 (4Y) in the experiment was due to high densification, small-size defect and high fracture toughness induced by compressive residual stress toughening and transformation toughening mechanisms; meanwhile, in despite of the moderate decrease in hardness, high flexural strength of Al2O3/45%ZrO2 (4Y) was considered to be a result of small-size defect in spherically-shaped micronmeter t-ZrO2 grain matrix and high fracture toughness induced by transformation toughening and micro-crack toughening mechanisms.

  7. Composition, microstructures and properties of Al{sub 2}O{sub 3}/ZrO{sub 2} (Y{sub 2}O{sub 3}) self-growing ceramic composites prepared by combustion synthesis under high gravity

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Z M; Zhang, L [Institute of Advanced Materials, Shijiazhuang Mechanical Engineering College, Shijiazhuang, 050003 (China); Song, Y G; Wang, W G; Liu, H B [Science Research Department, Shijiazhuang Mechanical Engineering College, Shijiazhuang, 050003 (China)], E-mail: zhao_zhongmin@163.net

    2009-03-01

    By introducing ZrO{sub 2} (4Y) powder into the thermit, Al{sub 2}O{sub 3}/ZrO{sub 2} (4Y) composite ceramics were prepared through combustion synthesis under high gravity, and the correlations of composition, microstructures and mechanical properties of composite ceramics were investigated. The results of XRD, SEM and EDS showed that Al{sub 2}O{sub 3}/33%ZrO{sub 2} (4Y) were composed of random-orientated rod-shaped colonies consisting of a triangular dispersion of orderly submicron-nanometer t-ZrO{sub 2} fibers, surrounded by inter-colony regions consisting of spherically-shaped micronmeter t-ZrO{sub 2} grains; Al{sub 2}O{sub 3}/45%ZrO{sub 2} (4Y) were comprised of spherically-shaped micron-meter t-ZrO{sub 2} grains, surround by irregularly-shaped {alpha}-Al{sub 2}O{sub 3} grains and a few colonies. Compared to the directionally solidified Al{sub 2}O{sub 3}/ZrO{sub 2} (Y{sub 2}O{sub 3}), the increase in hardness and flexural strength of Al{sub 2}O{sub 3}/33%ZrO{sub 2} (4Y) in the experiment was due to high densification, small-size defect and high fracture toughness induced by compressive residual stress toughening and transformation toughening mechanisms; meanwhile, in despite of the moderate decrease in hardness, high flexural strength of Al{sub 2}O{sub 3}/45%ZrO{sub 2} (4Y) was considered to be a result of small-size defect in spherically-shaped micronmeter t-ZrO{sub 2} grain matrix and high fracture toughness induced by transformation toughening and micro-crack toughening mechanisms.

  8. 40 CFR 503.44 - Operational standard-total hydrocarbons.

    Science.gov (United States)

    2010-07-01

    ... hydrocarbons. 503.44 Section 503.44 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... standard—total hydrocarbons. (a) The total hydrocarbons concentration in the exit gas from a sewage sludge incinerator shall be corrected for zero percent moisture by multiplying the measured total hydrocarbons...

  9. 21 CFR 172.882 - Synthetic isoparaffinic petroleum hydrocarbons.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Synthetic isoparaffinic petroleum hydrocarbons. 172... hydrocarbons. Synthetic isoparaffinic petroleum hydrocarbons may be safely used in food, in accordance with the... liquid hydrocarbons meeting the following specifications: Boiling point 93-260 °C as determined by ASTM...

  10. 40 CFR 86.317-79 - Hydrocarbon analyzer specifications.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Hydrocarbon analyzer specifications....317-79 Hydrocarbon analyzer specifications. (a) Hydrocarbon measurements are to be made with a heated... measures hydrocarbon emissions on a dry basis is permitted for gasoline-fueled testing; Provided, That...

  11. Cuticular Hydrocarbons: Species and Population-Level Discrimination in Termites

    Science.gov (United States)

    Michael I. Haverty; Marion Page; Barbara L. Thorne; Pierre Escoubas

    1991-01-01

    Hydrocarbons in the cuticle of insects are essential in protecting them from desiccation. The vast variety of hydrocarbons synthesized by insects and the apparent species-specificity of cuticular hydrocarbon mixtures make them excellent taxonomic characters for separating species within termite genera. Hydrocarbon phenotypes of dampwood termites, Zootermopsis...

  12. High Temperature Chemistry of Aromatic Hydrocarbons. Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Scott, Lawrence T. [Boston College, Chestnut Hill, MA (United States). Merkert Chemistry Center, Dept. of Chemistry

    2017-05-15

    synthesis of C60 and other fullerenes depended critically on a knowledge of hydrocarbon reactions at high temperatures in the gas phase, and the research supported by this project enabled further advances in the realm of carbon-rich materials.

  13. Hydrocarbon phenotyping of algal species using pyrolysis-gas chromatography mass spectrometry

    Directory of Open Access Journals (Sweden)

    Kothari Shankar L

    2010-05-01

    Full Text Available Abstract Background Biofuels derived from algae biomass and algae lipids might reduce dependence on fossil fuels. Existing analytical techniques need to facilitate rapid characterization of algal species by phenotyping hydrocarbon-related constituents. Results In this study, we compared the hydrocarbon rich algae Botryococcus braunii against the photoautotrophic model algae Chlamydomonas reinhardtii using pyrolysis-gas chromatography quadrupole mass spectrometry (pyGC-MS. Sequences of up to 48 dried samples can be analyzed using pyGC-MS in an automated manner without any sample preparation. Chromatograms of 30-min run times are sufficient to profile pyrolysis products from C8 to C40 carbon chain length. The freely available software tools AMDIS and SpectConnect enables straightforward data processing. In Botryococcus samples, we identified fatty acids, vitamins, sterols and fatty acid esters and several long chain hydrocarbons. The algae species C. reinhardtii, B. braunii race A and B. braunii race B were readily discriminated using their hydrocarbon phenotypes. Substructure annotation and spectral clustering yielded network graphs of similar components for visual overviews of abundant and minor constituents. Conclusion Pyrolysis-GC-MS facilitates large scale screening of hydrocarbon phenotypes for comparisons of strain differences in algae or impact of altered growth and nutrient conditions.

  14. Hydrocarbon phenotyping of algal species using pyrolysis-gas chromatography mass spectrometry

    Science.gov (United States)

    2010-01-01

    Background Biofuels derived from algae biomass and algae lipids might reduce dependence on fossil fuels. Existing analytical techniques need to facilitate rapid characterization of algal species by phenotyping hydrocarbon-related constituents. Results In this study, we compared the hydrocarbon rich algae Botryococcus braunii against the photoautotrophic model algae Chlamydomonas reinhardtii using pyrolysis-gas chromatography quadrupole mass spectrometry (pyGC-MS). Sequences of up to 48 dried samples can be analyzed using pyGC-MS in an automated manner without any sample preparation. Chromatograms of 30-min run times are sufficient to profile pyrolysis products from C8 to C40 carbon chain length. The freely available software tools AMDIS and SpectConnect enables straightforward data processing. In Botryococcus samples, we identified fatty acids, vitamins, sterols and fatty acid esters and several long chain hydrocarbons. The algae species C. reinhardtii, B. braunii race A and B. braunii race B were readily discriminated using their hydrocarbon phenotypes. Substructure annotation and spectral clustering yielded network graphs of similar components for visual overviews of abundant and minor constituents. Conclusion Pyrolysis-GC-MS facilitates large scale screening of hydrocarbon phenotypes for comparisons of strain differences in algae or impact of altered growth and nutrient conditions. PMID:20492649

  15. Gravity observations for hydrocarbon reservoir monitoring

    NARCIS (Netherlands)

    Glegola, M.A.

    2013-01-01

    In this thesis the added value of gravity observations for hydrocarbon reservoir monitoring and characterization is investigated. Reservoir processes and reservoir types most suitable for gravimetric monitoring are identified. Major noise sources affecting time-lapse gravimetry are analyzed. The

  16. Using microorganisms to aid in hydrocarbon degradation

    Energy Technology Data Exchange (ETDEWEB)

    Black, W.; Zamora, J. (Middle Tennessee State Univ., Murfreesboro (United States))

    1993-04-01

    Aliphatic hydrocarbons are threatening the potable water supply and the aquatic ecosystem. Given the right microbial inhabitant(s), a large portion of these aliphatic hydrocarbons could be biodegraded before reaching the water supply. The authors' purpose is to isolate possible oil-degrading organisms. Soil samples were taken from hydrocarbon-laden soils at petroleum terminals, a petroleum refinery waste-treatment facility, a sewage-treatment plant grease collector, a site of previous bioremediation, and various other places. Some isolates known to be good degraders were obtained from culture collection services. These samples were plated on a 10w-30 multigrade motor oil solid medium to screen for aliphatic hydrocarbon degraders. The degrading organisms were isolated, identified, and tested (CO[sub 2] evolution, BOD, and COD) to determine the most efficient degrader(s). Thirty-seven organisms were tested, and the most efficient degraders were Serratia marcescens, Escherichia coli, and Enterobacter agglomerans.

  17. Photocatalyzed oxidation of hydrocarbons in zeolite cages

    Energy Technology Data Exchange (ETDEWEB)

    Frei, H.; Blatter, F.; Sun, H. [Lawrence Berkeley National Lab., CA (United States)

    1996-06-01

    Oxidation of hydrocarbons by molecular oxygen is a key process in chemical industry. But reactions that use O{sub 2} as the primary oxidant often produce large amounts of unwanted byproducts. One major reason that selectivities are low is that the desired products (such as alcohols or carbonyls) are more easily oxidized by O{sub 2} than the parent hydrocarbon. The authors recently discovered a simple method that gives partial oxidation of small alkenes, alkanes, and alkyl-substituted benzenes by O{sub 2} at unprecedented selectivity, even at high conversion of the hydrocarbon. The approach is based on visible light-induced chemistry of hydrocarbon-O{sub 2} collisional pairs in the cages of large-pore zeolites. Reactions are conducted at ambient temperature in the absence of solvent or photosensitizer. Here the authors describe the most interesting reactions established thus far and define issues that pertain to scale-up of the method.

  18. Determination of carcinogenic polycyclic aromatic hydrocarbons ...

    African Journals Online (AJOL)

    Determination of carcinogenic polycyclic aromatic hydrocarbons (pahs), anthracene in different variety of fish samples in the Bangsai river of Bangladesh. F Yeasmin, SMM Rahman, S Rana, KJ Fatema, MA Hossain ...

  19. Infrared Spectra of Polycyclic Aromatic Hydrocarbons (PAHs)

    Science.gov (United States)

    Bauschlicher, Charles W., Jr.; Bakes, E. L. O.

    2000-01-01

    We have computed the synthetic infrared spectra of some polycyclic aromatic hydrocarbons containing up to 54 carbon atoms. The species studied include ovalene, circumcoronene, dicoronylene, and hexabenzocoronene. We report spectra for anions, neutrals, cations, and multiply charged cations.

  20. Informative document halogenated hydrocarbon-containing waste

    NARCIS (Netherlands)

    Verhagen H

    1992-01-01

    This "Informative document halogenated hydrocarbon-containing waste" forms part of a series of "Informative documents waste materials". These documents are conducted by RIVM on the instructions of the Directorate General for the Environment, Waste Materials Directorate, in

  1. Nitrocarburizing in ammonia-hydrocarbon gas mixtures

    DEFF Research Database (Denmark)

    Pedersen, Hanne; Christiansen, Thomas; Somers, Marcel A. J.

    2011-01-01

    The present work investigates the possibility of nitrocarburising in ammonia-acetylene-hydrogen and ammonia-propene-hydrogen gas mixtures, where unsaturated hydrocarbon gas is the carbon source during nitrocarburising. Consequently, nitrocarburising is carried out in a reducing atmosphere...... microscopy and X-ray diffraction analysis. It is shown that the use of unsaturated hydrocarbon gas in nitrocarburising processes is a viable alternative to traditional nitrocarburising methods....

  2. Nitrocarburising in ammonia-hydrocarbon gas mixtures

    DEFF Research Database (Denmark)

    Pedersen, Hanne; Christiansen, Thomas; Somers, Marcel A. J.

    2010-01-01

    The present work investigates the possibility of nitrocarburising in ammonia-acetylene-hydrogen and ammoniapropene- hydrogen gas mixtures, where unsaturated hydrocarbon gas is the carbon source during nitrocarburising. Consequently, nitrocarburising is carried out in a reducing atmosphere...... microscopy and X-ray diffraction analysis. It is shown that the use of unsaturated hydrocarbon gas in nitrocarburising processes is a viable alternative to traditional nitrocarburising methods....

  3. Zeolitic catalytic conversion of alochols to hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Narula, Chaitanya K.; Davison, Brian H.; Keller, Martin

    2017-01-03

    A method for converting an alcohol to a hydrocarbon, the method comprising contacting said alcohol with a metal-loaded zeolite catalyst at a temperature of at least 100.degree. C. and up to 550.degree. C., wherein said alcohol can be produced by a fermentation process, said metal is a positively-charged metal ion, and said metal-loaded zeolite catalyst is catalytically active for converting said alcohol to said hydrocarbon.

  4. Process for Photochemical Chlorination of Hydrocarbons

    Science.gov (United States)

    Beanblossom, W S

    1951-08-28

    A process for chlorination of a major portion of the hydrogen atoms of paraffinic hydrocarbons of five or more carbon atoms may be replaced by subjecting the hydrocarbon to the action of chlorine under active light. The initial chlorination is begun at 25 to 30 deg C with the chlorine diluted with HCl. The later stages may be carried out with undiluted chlorine and the temperature gradually raised to about 129 deg C.

  5. The future of oil and hydrocarbon man

    CERN Document Server

    Campbell, Colin

    1999-01-01

    Man appeared on the planet about four million years ago, and by 1850 numbered about one billion Ten came Hydrocarbon man. World population has since increased six-fold. After the oil price shocks of the 1970s, people asked "when will production peak?". It is not easy to answer this question because of the very poor database. Reserves and the many different hydrocarbon categories are poorly defined, reporting practices are ambiguous, revisions are not backdated...

  6. Hydrocarbon oxidation at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Warnatz, J.

    1983-11-01

    In this review it is described how, by suitable separation and elimination of unimportant reactions, a mechanism is developed with the aid of the present kinetic data for the elementary reactions involved. This mechanism explains, without fitting, the currently available experimental results for laminar premixed flames of alkanes, alkenes and acetylene. These experimental results are simulated by the solution of the corresponding conservation equations with suitable models describing diffusion and heat conduction in the multicomponent mixture considered. In lean and moderately rich flames the hydrocarbon is attacked by O, H, and OH in the first step. These radicals are produced by the chain-branching steps of the oxyhydrogen reaction. The alkyl radicals formed in this way always decompose to smaller alkyl radicals by fast thermal elimination of alkenes. Only the relatively slow thermal decomposition of the smallest alkyl radicals (CH/sub 3/ and C/sub 2/H/sub 5/) competes with recombination and with oxidation reactions by O atoms and O/sub 2/. This part of the mechanism is rate-controlling in the combustion of alkanes and alkenes, and is therefore the reason for the similarity of all alkane and alkene flames.

  7. Hydrocarbon habitat of the west Netherlands basin

    Energy Technology Data Exchange (ETDEWEB)

    De Jager, J. (Nederlandse Aardolie Maatschappij, Assen (Netherlands)); Doyle, M. (Petroleum Development Oman, Muscat (Oman)); Grantham, P. (KSEPL/Shell Research, Rijswijk (Netherlands)); Mabillard, J. (Shell Nigeria, Port Harcourt (Nigeria))

    1993-09-01

    The complex West Netherlands Basin contains oil and gas in Triassic and Upper Jurassic to Cretaceous clastic reservoir sequences. The understanding has always been that the Carboniferous coal measures have generated only gas and the Jurassic marine Posidonia Shale only oil. However, detailed geochemical analyses show that both source rocks have generated oil and gas. Geochemical fingerprinting established a correlation of the hydrocarbons with the main source rocks. The occurrence of these different hydrocarbons is consistent with migration routes. Map-based charge modeling shows that the main phase of hydrocarbon generation occurred prior to the Late Cretaceous inversion of the West Netherlands Basin. However, along the southwest flank of the basin and in lows between the inversion highs, significant charge continued during the Tertiary. Biodegradation of oils in Jurassic and Cretaceous reservoirs occurred during the earliest Tertiary, but only in reservoirs that were at that time at temperatures of less then 70 to 80[degrees]C, where bacteria could survive. This study shows that also in a mature hydrocarbon province an integrated hydrocarbon habitat study with modern analyses and state-of-the-art technology can lead to a much improved understanding of the distribution of oil and gas in the subsurface. The results of this study will allow a better risk assessment for remaining prospects, and an improved prediction of the type of trapped hydrocarbons in terms of gas, oil, and biodegraded oil.

  8. 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.

  9. Fiscal 1996 international research cooperation project. Feasibility study of finding out the seeds of international joint research (technology for effective use of saturated hydrocarbon, technology for reducing excess of aromatic hydrocarbon, high-grade treatment technology of petroleum coke); 1996 nendo kokusai kenkyu kyoryoku jigyo. Kokusai kyodo kenkyu seeds hakkutsu no tame no FS chosa (howa tanka suiso no yuko riyo gijutsu, hokozoku tanka suiso no yojo taisaku gijutsu, sekiyu cokes no kodo shori gijutsu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    This project is aimed at internationally cooperating in the R and D of industrial technology and improving industrial technology of Japan. For it, the following three technologies were investigated: (1) technology for effective use of saturated hydrocarbon, (2) technology for reducing excess of aromatic hydrocarbon, (3) high-grade treatment technology of petroleum coke. In (1), surveys were conducted of technologies of effective use of natural gas and effective use of C4 saturated hydrocarbon. Surveyed were a method for producing synthesis gas from natural gas, a technology to liquefy natural gas into fuel following the synthesis gas production process, a technology to liquefy natural gas into fuel without the synthesis gas production process, and the trend of effective use of C4 saturated hydrocarbon. In (2), surveys were made of process to reduce production of aromatic hydrocarbon as much as possible, process to effectively separate aromatic hydrocarbon, and process to convert excess aromatic hydrocarbon into polymer, etc. In (3), surveys were conducted on petroleum coke and pitch in terms of production methods, the supply/demand situation, property characteristics, usability to new fields, etc. 170 refs., 114 figs., 65 tabs.

  10. On the Radiolysis of Ethylene Ices by Energetic Electrons and Implications to the Extraterrestrial Hydrocarbon Chemistry

    Science.gov (United States)

    Zhou, Li; Maity, Surajit; Abplanalp, Matt; Turner, Andrew; Kaiser, Ralf I.

    2014-07-01

    The chemical processing of ethylene ices (C2H4) by energetic electrons was investigated at 11 K to simulate the energy transfer processes and synthesis of new molecules induced by secondary electrons generated in the track of galactic cosmic ray particles. A combination of Fourier transform infrared spectrometry (solid state) and quadrupole mass spectrometry (gas phase) resulted in the identification of six hydrocarbon molecules: methane (CH4), the C2 species acetylene (C2H2), ethane (C2H6), the ethyl radical (C2H5), and—for the very first time in ethylene irradiation experiments—the C4 hydrocarbons 1-butene (C4H8) and n-butane (C4H10). By tracing the temporal evolution of the newly formed molecules spectroscopically online and in situ, we were also able to fit the kinetic profiles with a system of coupled differential equations, eventually providing mechanistic information, reaction pathways, and rate constants on the radiolysis of ethylene ices and the inherent formation of smaller (C1) and more complex (C2, C4) hydrocarbons involving carbon-hydrogen bond ruptures, atomic hydrogen addition processes, and radical-radical recombination pathways. We also discuss the implications of these results on the hydrocarbon chemistry on Titan's surface and on ice-coated, methane-bearing interstellar grains as present in cold molecular clouds such as TMC-1.

  11. Active Hydrocarbon Biosynthesis and Accumulation in a Green Alga, Botryococcus braunii (Race A)

    Science.gov (United States)

    Hirose, Mana; Mukaida, Fukiko; Okada, Sigeru

    2013-01-01

    Among oleaginous microalgae, the colonial green alga Botryococcus braunii accumulates especially large quantities of hydrocarbons. This accumulation may be achieved more by storage of lipids in the extracellular space rather than in the cytoplasm, as is the case for all other examined oleaginous microalgae. The stage of hydrocarbon synthesis during the cell cycle was determined by autoradiography. The cell cycle of B. braunii race A was synchronized by aminouracil treatment, and cells were taken at various stages in the cell cycle and cultured in a medium containing [14C]acetate. Incorporation of 14C into hydrocarbons was detected. The highest labeling occurred just after septum formation, when it was about 2.6 times the rate during interphase. Fluorescent and electron microscopy revealed that new lipid accumulation on the cell surface occurred during at least two different growth stages and sites of cells. Lipid bodies in the cytoplasm were not prominent in interphase cells. These lipid bodies then increased in number, size, and inclusions, reaching maximum values just before the first lipid accumulation on the cell surface at the cell apex. Most of them disappeared from the cytoplasm concomitant with the second new accumulation at the basolateral region, where extracellular lipids continuously accumulated. The rough endoplasmic reticulum near the plasma membrane is prominent in B. braunii, and the endoplasmic reticulum was often in contact with both a chloroplast and lipid bodies in cells with increasing numbers of lipid bodies. We discuss the transport pathway of precursors of extracellular hydrocarbons in race A. PMID:23794509

  12. I. Textural/Structural tuning and nanoparticle stabilization of copper-containing nanocomposite materials. II. Generation of reducing agents for automotive exhaust gas purification via the processing of hydrocarbons in a PACT (plasma and catalysis integrated technologies) reactor

    Science.gov (United States)

    Xing, Yu

    This research consists of two parts. The first part deals with the preparation and properties of copper-containing nanocomposite materials. For studies of textural tuning, structural tuning, or material sintering, copper/aluminum and copper/zinc nanocomposites were prepared via various inorganic synthesis methods including conventional coprecipitation methods and a novel urea-gelation/thermal-modification method that produces narrow distributions of pore sizes, high surface areas, and significantly higher specific metal loadings. Solid-solid reaction analysis and differential scanning calorimetry (DSC) analysis were developed for the determination of the mixing homogeneities of the copper/aluminum nanocomposites. A sintering experiment at 250-600°C for 350 h under methanol-steam reforming conditions was carried out to compare the stability of supported Cu0 nanoparticles. The mixing homogeneities of CuO/Al2O3 nanocomposites significantly affected the thermal stability of their reduced Cu0 crystallites. Creation of relatively narrow distributions of pore sizes with relatively small major pore diameters (e.g., 3.5 nm) can also be used for the stabilization of supported Cu0 nanoparticles. The supported nanoparticles with a relatively small initial size cannot ensure good thermal stability. A "hereditary" character on the homogeneity of copper/aluminum nanocomposites was revealed. Stepwise reduction and reoxidation were studied for the structural tuning and purification of Cu-Al-O spinels with isotropic and gradual unit-cell contractions. The second part of the research deals with the processing of hydrocarbons. Conversion of a model hydrocarbon (n-hexane or n-octane) in an AC discharge PACT (plasma and catalysis integrated technologies) reactor was verified to be an effective method to instantly produce reducing agents (e.g., hydrogen or/and light alkanes and alkenes), at room temperature and atmospheric pressure for automotive exhaust gas purification. Effects of

  13. Novel Aryne Chemistry in Organic Synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zhijian [Iowa State Univ., Ames, IA (United States)

    2006-12-12

    Arynes are among the most intensively studied systems in chemistry. However, many aspects of the chemistry of these reactive intermediates are not well understood yet and their use as reagents in synthetic organic chemistry has been somewhat limited, due to the harsh conditions needed to generate arynes and the often uncontrolled reactivity exhibited by these species. Recently, o-silylaryl triflates, which can generate the corresponding arynes under very mild reaction conditions, have been found very useful in organic synthesis. This thesis describes several novel and useful methodologies by employing arynes, which generate from o-silylaryl triflates, in organic synthesis. An efficient, reliable method for the N-arylation of amines, sulfonamides and carbamates, and the O-arylation of phenols and carboxylic acids is described in Chapter 1. Amines, sulfonamides, phenols, and carboxylic acids are good nucleophiles, which can react with arynes generated from a-silylaryl triflates to afford the corresponding N- and O-arylated products in very high yields. The regioselectivity of unsymmetrical arynes has also been studied. A lot of useful, functional groups can tolerate our reaction conditions. Carbazoles and dibenzofurans are important heteroaromatic compounds, which have a variety of biological activities. A variety of substituted carbazoles and dibenzofwans are readily prepared in good to excellent yields starting with the corresponding o-iodoanilines or o-iodophenols and o-silylaryl triflates by a treatment with CsF, followed by a Pd-catalyzed cyclization, which overall provides a one-pot, two-step process. By using this methodology, the carbazole alkaloid mukonine has been concisely synthesized in a very good yield. Insertion of an aryne into a σ-bond between a nucleophile and an electrophile (Nu-E) should potentially be a very beneficial process from the standpoint of organic synthesis. A variety of substituted ketones and sulfoxides have been synthesized in good

  14. Solution preparation

    Energy Technology Data Exchange (ETDEWEB)

    Seitz, M.G.

    1982-01-01

    Reviewed in this statement are methods of preparing solutions to be used in laboratory experiments to examine technical issues related to the safe disposal of nuclear waste from power generation. Each approach currently used to prepare solutions has advantages and any one approach may be preferred over the others in particular situations, depending upon the goals of the experimental program. These advantages are highlighted herein for three approaches to solution preparation that are currently used most in studies of nuclear waste disposal. Discussion of the disadvantages of each approach is presented to help a user select a preparation method for his particular studies. Also presented in this statement are general observations regarding solution preparation. These observations are used as examples of the types of concerns that need to be addressed regarding solution preparation. As shown by these examples, prior to experimentation or chemical analyses, laboratory techniques based on scientific knowledge of solutions can be applied to solutions, often resulting in great improvement in the usefulness of results.

  15. Method and apparatus for producing synthesis gas

    Science.gov (United States)

    Hemmings, John William; Bonnell, Leo; Robinson, Earl T.

    2010-03-03

    A method and apparatus for reacting a hydrocarbon containing feed stream by steam methane reforming reactions to form a synthesis gas. The hydrocarbon containing feed is reacted within a reactor having stages in which the final stage from which a synthesis gas is discharged incorporates expensive high temperature materials such as oxide dispersed strengthened metals while upstream stages operate at a lower temperature allowing the use of more conventional high temperature alloys. Each of the reactor stages incorporate reactor elements having one or more separation zones to separate oxygen from an oxygen containing feed to support combustion of a fuel within adjacent combustion zones, thereby to generate heat to support the endothermic steam methane reforming reactions.

  16. Determination of the aromatic hydrocarbon to total hydrocarbon ratio of mineral oil in commercial lubricants.

    Science.gov (United States)

    Uematsu, Yoko; Suzuki, Kumi; Ogimoto, Mami

    2016-01-01

    A method was developed to determine the aromatic hydrocarbon to total hydrocarbon ratio of mineral oil in commercial lubricants; a survey was also conducted of commercial lubricants. Hydrocarbons in lubricants were separated from the matrix components of lubricants using a silica gel solid phase extraction (SPE) column. Normal-phase liquid chromatography (NPLC) coupled with an evaporative light-scattering detector (ELSD) was used to determine the aromatic hydrocarbon to total hydrocarbon ratio. Size exclusion chromatography (SEC) coupled with a diode array detector (DAD) and a refractive index detector (RID) was used to estimate carbon numbers and the presence of aromatic hydrocarbons, which supplemented the results obtained by NPLC/ELSD. Aromatic hydrocarbons were not detected in 12 lubricants specified for use for incidental food contact, but were detected in 13 out of 22 lubricants non-specified for incidental food contact at a ratio up to 18%. They were also detected in 10 out of 12 lubricants collected at food factories at a ratio up to 13%. The centre carbon numbers of hydrocarbons in commercial lubricants were estimated to be between C16 and C50.

  17. Volatile hydrocarbons inhibit methanogenic crude oil degradation

    Directory of Open Access Journals (Sweden)

    Angela eSherry

    2014-04-01

    Full Text Available Methanogenic degradation of crude oil in subsurface sediments occurs slowly, but without the need for exogenous electron acceptors, is sustained for long periods and has enormous economic and environmental consequences. Here we show that volatile hydrocarbons are inhibitory to methanogenic oil biodegradation by comparing degradation of an artificially weathered crude oil with volatile hydrocarbons removed, with the same oil that was not weathered. Volatile hydrocarbons (nC5-nC10, methylcyclohexane, benzene, toluene and xylenes were quantified in the headspace of microcosms. Aliphatic (n-alkanes nC12-nC34 and aromatic hydrocarbons (4-methylbiphenyl, 3-methylbiphenyl, 2-methylnaphthalene, 1-methylnaphthalene were quantified in the total hydrocarbon fraction extracted from the microcosms. 16S rRNA genes from key microorganisms known to play an important role in methanogenic alkane degradation (Smithella and Methanomicrobiales were quantified by quantitative PCR. Methane production from degradation of weathered oil in microcosms was rapid (1.1 ± 0.1 µmol CH4/g sediment/day with stoichiometric yields consistent with degradation of heavier n-alkanes (nC12-nC34. For non-weathered oil, degradation rates in microcosms were significantly lower (0.4 ± 0.3 µmol CH4/g sediment/day. This indicated that volatile hydrocarbons present in the non-weathered oil inhibit, but do not completely halt, methanogenic alkane biodegradation. These findings are significant with respect to rates of biodegradation of crude oils with abundant volatile hydrocarbons in anoxic, sulphate-depleted subsurface environments, such as contaminated marine sediments which have been entrained below the sulfate-reduction zone, as well as crude oil biodegradation in petroleum reservoirs and contaminated aquifers.

  18. Fast synthesis of the polycrystalline materials on the base of Zn 3 V2 MoO11 and Zn 2.5 VMoO8

    Directory of Open Access Journals (Sweden)

    Maya Markova-Velichkova

    2009-12-01

    Full Text Available In our study we applied two different techniques for the preparation of Zn3V2MoO11 and Zn2.5VMoO8 polycrystalline materials - melt quenching method (up-bottom and mechanochemical synthesis (bottom- up. These compounds belong to the family of materials with general formula M2.5VMoO8 (M=Zn, Mg, Mn, Co. They are potential candidates as catalysts in processes of selective oxidation of hydrocarbons. Until now, these two compounds were obtained by conventional solid state reaction. Using infrared spectroscopy and X-ray diffraction we proved that the melt quenching technique is a quite appropriate method for the synthesis of bulk Zn3V2-MoO11 phase. Mechanochemical activation is more appropriated for the preparation of nonosized Zn2.5VMoO8 powder. It was established that the melt quenching technique and mechanochemical activation are faster in comparison with conventional ceramic methods for the given synthesis.

  19. 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

  20. Reactive organometallics from organotellurides: application in organic synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Princival, Jefferson L.; Santos, Alcindo A. dos; Comasseto, Joao V., E-mail: jvcomass@iq.usp.b [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Quimica

    2010-07-01

    In this paper the preparation of reactive organometallics starting from organotellurides is reviewed. The application of the reactive organometallics prepared in this way in the synthesis of bioactive compounds is commented. (author)