WorldWideScience

Sample records for characterizing effusive-flow properties

  1. Effusive-Flow of Pure Elemental Species in Tubular Transport Systems: Radioactive Ion Beam Applications

    International Nuclear Information System (INIS)

    Maximum practically achievable intensities are required for research with accelerated radioactive ion beams (RIBs). Time delays due to diffusion of radioactive species from solid or liquid target materials and their effusive-flow transport to the ion source can severely limit intensities of short-lived radioactive beams, and therefore, such delays must be minimized. An analytical formula has been developed that can be used to calculate characteristic effusive-flow times through tubular transport systems, independent of species, tube material, and operational temperature for ideal cases. Thus, the equation permits choice of materials of construction on a relative basis that minimize transport times of atoms or molecules moving through the system, independent of transport system geometry and size. In this report, we describe the formula and compare results derived by its use with those determined by use of Monte-Carlo techniques

  2. Simulation Studies of Diffusion-Release and Effusive-Flow of Short-Lived Radioactive Isotopes

    CERN Document Server

    Zhang, Yan; Kawai, Yoko

    2005-01-01

    Delay times associated with diffusion release from targets and effusive-flow transport of radioactive isotopes to ion sources are principal intensity limiters at ISOL-based radioactive ion beam facilities, and simulation studies with computer models are cost effective methods for designing targets and vapor transport systems with minimum delay times to avoid excessive decay losses of short lived ion species. A finite difference code, Diffuse II, was recently developed at the Oak Ridge National Laboratory to study diffusion-release of short-lived species from three principal target geometries. Simulation results are in close agreement with analytical solutions to Fick’s second equation. Complementary to the development of Diffuse II, the Monte-Carlo code, Effusion, was developed to address issues related to the design of fast vapor transport systems. Results, derived by using Effusion, are also found to closely agree with experimental measurements. In this presentation, the codes will be used in conc...

  3. Seismic characterization of fracture properties

    International Nuclear Information System (INIS)

    A critical component of site characterization and performance assessment involves the demonstration that any fluid flow which might reach the accessible environment is within acceptable limits. Various methods of analyzing flow in fractured rocks have been proposed, but choice of an appropriate method and its application to a specific site probably requires some knowledge of the spacing and length (or density) of fractures, their orientation and their hydraulic conductivity. Some of this information will undoubtedly come from geologic mapping on surface and in excavations, as well as from boreholes, cores and laboratory tests. However, it will be necessary to detect and characterize fractures in the rock mass between these direct observations. The remote detection and characterization of fractures by geophysical methods is, therefore, of considerable interest in connection with geologic repositories. The purpose of this paper is to show that there is a relationship, both empirical and theoretical, between the measured seismic response, the mechanical stiffness of fractures and their hydraulic conductivity. Laboratory measurements of the mechanical stiffness, hydraulic conductivity and seismic properties of natural fractures are summarized. A theoretical model for the amplitude and group time delay for compressional and shear waves transmitted across a single fracture is presented. Predictions based on this model are compared with laboratory measurements. Finally, the results for a single fracture are extended to multiple parallel fractures

  4. Accelerated Characterization of Polymer Properties

    Energy Technology Data Exchange (ETDEWEB)

    R. Wroczynski; l. Brewer; D. Buckley; M. Burrell; R. Potyrailo

    2003-07-30

    This report describes the efforts to develop a suite of microanalysis techniques that can rapidly measure a variety of polymer properties of industrial importance, including thermal, photo-oxidative, and color stability; as well as ductility, viscosity, and mechanical and antistatic properties. Additional goals of the project were to direct the development of these techniques toward simultaneous measurements of multiple polymer samples of small size in real time using non-destructive and/or parallel or rapid sequential measurements, to develop microcompounding techniques for preparing polymers with additives, and to demonstrate that samples prepared in the microcompounder could be analyzed directly or used in rapid off-line measurements. These enabling technologies are the crucial precursors to the development of high-throughput screening (HTS) methodologies for the polymer additives industry whereby the rate of development of new additives and polymer formulations can be greatly accelerated.

  5. Seismic characterization of fracture properties

    International Nuclear Information System (INIS)

    The purpose of this paper is to show that there is a relationship, both empirical and theoretical, between the measured seismic response, the mechanical stiffness (also referred to as specific stiffness) of fractures and their hydraulic conductivity. Laboratory measurements of the mechanical stiffness, hydraulic conductivity and seismic properties of natural fractures are summarized. A theoretical model for the amplitude and group time delay for compressional and shear waves transmitted across a single fracture is presented. Predictions based on this model are compared with laboratory measurements. Finally, the results for a single fracture are extended to multiple parallel fractures. 13 refs., 6 figs

  6. Characterization of transport properties of wasteform mixtures

    International Nuclear Information System (INIS)

    This study investigates the transport properties of different wasteform mixtures. The objective is to collect data to model the long-term service-life of a cement barrier/wasteform system and see how the wasteform affect the durability of the storage structure, which is expected to last many thousand years. Two different wasteform mixtures incorporating different slag and fly ash contents were tested. The materials were characterized using different experimental tests in order to estimate tortuosity, porosity, permeability and pore size distribution. The tests showed that despite a very high porosity, the wasteform mixtures exhibit very low transport properties values. Immersion tests in NaCl solution showed very slow chloride ingress in accordance with the transport properties. Furthermore, the two formulations showed a significant improvement in properties when slag content was increased. (authors)

  7. Graphene optoelectronics synthesis, characterization, properties, and applications

    CERN Document Server

    bin M Yusoff, Abdul Rashid

    2014-01-01

    This first book on emerging applications for this innovative material gives an up-to-date account of the many opportunities graphene offers high-end optoelectronics.The text focuses on potential as well as already realized applications, discussing metallic and passive components, such as transparent conductors and smart windows, as well as high-frequency devices, spintronics, photonics, and terahertz devices. Also included are sections on the fundamental properties, synthesis, and characterization of graphene. With its unique coverage, this book will be welcomed by materials scientists, solid-

  8. Structural characterization and pharmaceutical properties of porphyran

    Directory of Open Access Journals (Sweden)

    Saurabh Bhatia

    2015-01-01

    Full Text Available Marine polysaccharides remain an untapped reservoir for development of novel biomaterials. Algae derived sulfated polysaccharides (SPs have their interesting pharmaceutical and biological properties. Degree and pattern of sulfation of such biopolymers favors their binding property with tissues when compared with non-SPs. Due to the gel formation potential, hydrocolloids such as agar, carrageenan, fucoidan, and alginate are extensively studied food and nonfood applications. Degree of sulfation and favorable physical properties are essentially required for tissue engineering applications. Therefore, our investigation explores the structural and gelling properties of novel polysaccharide porphyran (POR isolated from Porphyra vietnamensis by alkali hydrolysis. Percentage yield of POR was found to be 19.7%. The sulfate content of the polysaccharide was 11.1% and the main sugars present were D-galactose (16.1%, 3, 6-anhydro galactose (3, 6-AG (10.1% and 6-O-methyl D-galactose (7.81%. After hydrolysis D-galactose was again confirmed by paper chromatography (Rf: 0.8 and phenol-sulfuric acid method. Gelling properties, including gelling strength (241 g/cm 2 , gelling temperature (35.8°C, melting temperature (70.7 ± 0.4 and apparent viscosity (56.2 η were also explored. Differential scanning calorimeter analysis showed purified fraction has gel melt between 70°C and 80°C and show glass transition between 35°C and 38°C. Viscometric analysis was examined to analyze the different behavior of SPs fraction under the influence of cationic and anionic salts and polysaccharides. Molecular mass of POR was determined (16,280. SPs were characterized by Fourier transform infrared and nuclear magnetic resonance spectroscopy, which showed the presence of linear backbone structure called as POR. The rheological behavior of POR exhibits a gel-like behavior close to the one observed in commercial agar.

  9. Synthesis, characterization and optical properties of nanoparticles

    Science.gov (United States)

    Li, Shoutian

    ZnO, Si, silica, Ge, Ga oxide, W oxide and Mo oxide nanoparticles have been synthesized and characterized, and their optical properties have been investigated. These particles were synthesized by a Laser Vaporization and Controlled Condensation (LVCC) technique in a modified diffusion cloud chamber. The particles deposited on smooth substrates reveal highly organized web-like structures with uniform micrometer size pores. The effect of solvents on the web-like structures was also investigated. ZnO nanoparticles were also prepared by wet chemical methods such as the reversed micelle and sol solutions technique. The photoluminescence quantum yield is enhanced 10 times once the surfaces of the ZnO nanoparticles are coated with a layer of stearate molecules. Many techniques have been used to characterize the nanoparticles. SEM gives information about particle size and morphology; X-ray diffraction and Raman spectroscopy determine the crystallinity and crystal structure; XPS and FTIR reveal the surface chemical composition; UV-vis spectroscopy and photoluminescence measurements characterize the optical properties of nanoparticles. Silica nanoparticles, prepared in an amorphous phase, show bright blue photoluminescence upon irradiation with UV light, but the luminescence has a very short lifetime (less than 20 ns). Si nanoparticles, with a diamond-like crystal phase, acquire oxidized-surfaces on exposure to air. The surface-oxidized Si nanocrystals show a short- lived blue emission characteristic of the SiO2 coating and a longer-lived red emission at room temperature. The lifetime of the red emission depends on the emission wavelength. Some substituted benzene molecules and tungsten oxide nanoparticles can quench the red photoluminescence of the Si nanocrystals. Tungsten oxide and molybdenum oxide nanoparticles show photochromic properties: they change color to blue when irradiated. The photons drive a transition from one chemical state to another. The color change of

  10. Novel metallomesogenic polyurethanes: Synthesis, characterization and properties

    International Nuclear Information System (INIS)

    A series of tetradentate Schiff base metallomesogenic diols were synthesized from two simple dihydroxy benzenes. The metallomesogenic diol was constructed from three ring containing mesogen linked through ester and azomethine with terminal hydroxy group. This upon complexation with copper(II) formed metallomesogenic diol with varying terminal chain length. A series of metallomesogenic polyurethanes were synthesized using these metallomesogenic diols as chain extenders for the prepolymers based on polytetramethylene glycol (PTMG) of varying molecular weight (Mn = 650, 2000) and 2,4-toluene diisocyanate (TDI), or 4,4′-methylene bis(phenyl isocyanate) (MDI). The molar ratio of metallomesogenic diol and PTMG were varied in the polyurethane to find their role in liquid crystalline and mechanical properties. Extensive characterization of all metallomesogenic compounds and intermediates were carried out by FT-IR, 1H and 13C NMR, EPR, VSM, Mass (EI and FAB) and UV–visible spectroscopy. Hot stage polarizing microscope and differential scanning calorimetry were used to ensure the phase characteristics such as nature of phase, melting and clearing temperatures and phase range. The appearance of enantiotropic smectic A phases indicated high molecular polarizability of the core due to the metal ion. - Highlights: ► Design and synthesis of metallomesogenic diols. ► Metallomesogenic polyurethanes were prepared using these diols as chain extenders. ► Liquid crystalline and mechanical properties were studied. ► A square pyramidal structure for the copper(II) complexes have been proposed. ► Polyurethanes exhibited enantiotropic smectic A phases.

  11. Novel metallomesogenic polyurethanes: Synthesis, characterization and properties

    Energy Technology Data Exchange (ETDEWEB)

    Senthilkumar, Natarajan, E-mail: nskumar77@yahoo.com [Production Technology Research Center, Samsung Cheil Industries, 62 Pyeongyeo-dong, Yeosu-si, JeonNam 555-210 (Korea, Republic of); Narasimhaswamy, Tanneru [Polymer Laboratory, Central Leather Research Institute, Chennai 600 020 (India); Kim, Il-Jin [Production Technology Research Center, Samsung Cheil Industries, 62 Pyeongyeo-dong, Yeosu-si, JeonNam 555-210 (Korea, Republic of)

    2012-12-01

    A series of tetradentate Schiff base metallomesogenic diols were synthesized from two simple dihydroxy benzenes. The metallomesogenic diol was constructed from three ring containing mesogen linked through ester and azomethine with terminal hydroxy group. This upon complexation with copper(II) formed metallomesogenic diol with varying terminal chain length. A series of metallomesogenic polyurethanes were synthesized using these metallomesogenic diols as chain extenders for the prepolymers based on polytetramethylene glycol (PTMG) of varying molecular weight (M{sub n} = 650, 2000) and 2,4-toluene diisocyanate (TDI), or 4,4 Prime -methylene bis(phenyl isocyanate) (MDI). The molar ratio of metallomesogenic diol and PTMG were varied in the polyurethane to find their role in liquid crystalline and mechanical properties. Extensive characterization of all metallomesogenic compounds and intermediates were carried out by FT-IR, {sup 1}H and {sup 13}C NMR, EPR, VSM, Mass (EI and FAB) and UV-visible spectroscopy. Hot stage polarizing microscope and differential scanning calorimetry were used to ensure the phase characteristics such as nature of phase, melting and clearing temperatures and phase range. The appearance of enantiotropic smectic A phases indicated high molecular polarizability of the core due to the metal ion. - Highlights: Black-Right-Pointing-Pointer Design and synthesis of metallomesogenic diols. Black-Right-Pointing-Pointer Metallomesogenic polyurethanes were prepared using these diols as chain extenders. Black-Right-Pointing-Pointer Liquid crystalline and mechanical properties were studied. Black-Right-Pointing-Pointer A square pyramidal structure for the copper(II) complexes have been proposed. Black-Right-Pointing-Pointer Polyurethanes exhibited enantiotropic smectic A phases.

  12. Characterizing Hilbert space frames with the subframe property

    OpenAIRE

    Casazza, Peter G.

    1998-01-01

    We characterize Riesz frames and frames with the subframe property and use this to answer most of the questions from the literature concerning these properties and their relationships to the projection methods etc.

  13. Characterization And Dissolution Properties Of Ruthenium Oxides

    Science.gov (United States)

    Ruthenium oxides (RuO2•1.10H2O and RuO2) have been synthesized by forced hydrolysis and oxidation of ruthenium chloride. The resulting materials were extensively characterized to determine the crystallinity, surface area, and ruthenium oxidation ...

  14. Possibilities and Limits of Texture Properties Characterization.

    Czech Academy of Sciences Publication Activity Database

    Šolcová, Olga; Matějová, Lenka; Schneider, Petr

    Kyiv : -, 2007. s. P12. [Sol-Gel Approaches to Materials for Pollution Control, Water Purification and Soil Remediation. 25.10.2007-27.10.2007, Kyiv] R&D Projects: GA AV ČR(CZ) KAN400720701 Institutional research plan: CEZ:AV0Z40720504 Keywords : physical adsorption * pore-size distribution * textural properties Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  15. Materials thermal and thermoradiative properties/characterization technology

    Science.gov (United States)

    Dewitt, D. P.; Ho, C. Y.

    1989-01-01

    Reliable properties data on well characterized materials are necessary for design of experiments and interpretation of experimental results. The activities of CINDAS to provide data bases and predict properties are discussed. An understanding of emissivity behavior is important in order to select appropriate methods for non-contact temperature determination. Related technical issues are identified and recommendations are offered.

  16. Fabrication, characterization, and thermal property evaluation of silver nanofluids

    OpenAIRE

    Noroozi, Monir; Radiman, Shahidan; Zakaria, Azmi; Soltaninejad, Sepideh

    2014-01-01

    Silver nanoparticles were successfully prepared in two different solvents using a microwave heating technique, with various irradiation times. The silver nanoparticles were dispersed in polar liquids (distilled water and ethylene glycol) without any other reducing agent, in the presence of the stabilizer polyvinylpyrrolidone (PVP). The optical properties, thermal properties, and morphology of the synthesized silver particles were characterized using ultraviolet-visible spectroscopy, photopyro...

  17. Characterization and nultivariate analysis of physical properties of processing peaches

    Science.gov (United States)

    Characterization of physical properties of fruits represents the first vital step to ensure optimal performance of fruit processing operations and is also a prerequisite in the development of new processing equipment. In this study, physical properties of engineering significance to processing of th...

  18. Properties Characterization of Chemically Modified Hemp Hurds

    OpenAIRE

    Nadezda Stevulova; Julia Cigasova; Adriana Estokova; Eva Terpakova; Anton Geffert; Frantisek Kacik; Eva Singovszka; Marian Holub

    2014-01-01

    The effect of chemical treatment of hemp hurds slices in three solutions (EDTA (Ethylenediaminetetraacetic acid), NaOH and Ca(OH)2) on the properties of natural material was discussed in this paper. Changes in the morphology, chemical composition and structure as well as thermal stability of hemp hurds before and after their modification were investigated by using FTIR (Fourier transform infrared spectroscopy), XRD (X-ray powder diffraction analysis) and TG (thermogravimetry)/DSC (differentia...

  19. Microstructural characterization and mechanical property evaluation of microalloyed steel

    OpenAIRE

    Om Prakash Tenduwe; Pawan Kumar Sahu

    2015-01-01

    Experimental evaluation of microstructural and mechanical property of any material is very important for knowing their serviceability, various properties and behavior in different operational conditions. These parametric properties can be used to predict their proper utilization, life prediction, service reliability and operational safety in various condition. The material used in this investigation is a micro alloyed steel. The micro structural characterizations have been done th...

  20. Characterization of Chemical and Mechanical Properties of Polymer Based Nanocomposites

    OpenAIRE

    Wafy, Tamer

    2013-01-01

    Characterization of Chemical and Mechanical Properties of Polymer Based NanocompositesThe University of ManchesterTamer Wafy Doctor of Philosophy17 January, 2013One of the most significant issues in nanocomposite performance is improving the dispersion of carbon nanotubes (CNTs) in thermosetting or thermoplastic polymers in order to gain good mechanical properties. Several studies have investigated the fabrication of nanocomposites based on carbon nanotubes and analysed properties, but there ...

  1. Properties Characterization of Chemically Modified Hemp Hurds

    Directory of Open Access Journals (Sweden)

    Nadezda Stevulova

    2014-12-01

    Full Text Available The effect of chemical treatment of hemp hurds slices in three solutions (EDTA (Ethylenediaminetetraacetic acid, NaOH and Ca(OH2 on the properties of natural material was discussed in this paper. Changes in the morphology, chemical composition and structure as well as thermal stability of hemp hurds before and after their modification were investigated by using FTIR (Fourier transform infrared spectroscopy, XRD (X-ray powder diffraction analysis and TG (thermogravimetry/DSC (differential scanning calorimetry. Size exclusion chromatography (SEC measurements were used for determination of degree of cellulose polymerization of hemp hurd samples. Chemical modification is related to the partial removal of non-cellulosic components of lignin, hemicellulose and pectin as well as waxes from the surface of hemp hurd slices. Another effect of the chemical treatment applied is connected with increasing the crystallinity index of cellulose determined by FTIR and XRD methods. Decrease in degree of cellulose polymerization and polydispersity index in chemically modified hemp hurds compared to the original sample was observed. Increase in thermal stability of treated hemp hurd was found. The most significant changes were observed in alkaline treated hemp hurds by NaOH.

  2. Characterization and dissolution properties of ruthenium oxides.

    Science.gov (United States)

    Luxton, Todd P; Eick, Matthew J; Scheckel, Kirk G

    2011-07-01

    Ruthenium oxides (RuO(2)·1·10H(2)O and RuO(2)) have been synthesized by forced hydrolysis and oxidation of ruthenium chloride. The resulting materials were extensively characterized to determine the crystallinity, surface area, and ruthenium oxidation state. Surface charging experiments indicate a large quantity of reactive functional groups for both materials and a decrease in the acidity of the surface functional groups with crystallization of the hydrous oxide. Dissolution studies conducted in acidic and basic pH environments indicate Ru-oxides are insoluble in 0.1 M HCl and slightly soluble in 0.1 M NaOH. Oxalate and ascorbate (5 mM) promoted dissolution of RuO(2)·1·10H(2)O demonstrated an increase in dissolution rates with decreasing pH and increasing ligand surface coverage. XPS analysis of the RuO(2)·1·10H(2)O surface after ligand promoted dissolution revealed the reduction of Ru(IV) to Ru(III) indicating that both ascorbate and oxalate reductively dissolve RuO(2)·1·10H(2)O. Dissolution experiments with RuO(2) resulted in dissolution only for 5 mM oxalate at pH 3. Dissolution rates calculated for RuO(2)·1·10H(2)O and RuO(2) are compared with previously published dissolution rates for iron oxides, demonstrating an order of magnitude decrease in the oxalate and ascorbate promoted dissolution. PMID:21511266

  3. Computational characterization and prediction of metal-organic framework properties

    OpenAIRE

    Coudert, François-Xavier; Fuchs, Alain H

    2015-01-01

    In this introductory review, we give an overview of the computational chemistry methods commonly used in the field of metal-organic frameworks (MOFs), to describe or predict the structures themselves and characterize their various properties, either at the quantum chemical level or through classical molecular simulation. We discuss the methods for the prediction of crystal structures, geometrical properties and large-scale screening of hypothetical MOFs, as well as their thermal and mechanica...

  4. Microstructural characterization and mechanical property evaluation of microalloyed steel

    Directory of Open Access Journals (Sweden)

    Om Prakash Tenduwe

    2015-04-01

    Full Text Available Experimental evaluation of microstructural and mechanical property of any material is very important for knowing their serviceability, various properties and behavior in different operational conditions. These parametric properties can be used to predict their proper utilization, life prediction, service reliability and operational safety in various condition. The material used in this investigation is a micro alloyed steel. The micro structural characterizations have been done through optical microscopy as well as SEM and various mechanical property evaluation were done through tensile test, hardness test and Charpy impact toughness tests in different orientations. The results have been used to predict the serviceability, and it is observed from this study that this steel contains good amount of ferrite-pearlite combination, and this material show the high tensile strength and better mechanical property for utilizing in the field of automotive and piping industry.

  5. Thermophysical property characterization of tris(hydroxymethyl)aminomethane

    Energy Technology Data Exchange (ETDEWEB)

    Soriano, Allan N. [R and D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan Christian University, Chung Li 32023, Taiwan (China); School of Chemical Engineering and Chemistry, Mapua Institute of Technology, Manila 1002 (Philippines); Cabahug, Denise Irene V. [School of Chemical Engineering and Chemistry, Mapua Institute of Technology, Manila 1002 (Philippines); Li Menghui, E-mail: mhli@cycu.edu.t [R and D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan Christian University, Chung Li 32023, Taiwan (China)

    2011-02-15

    In this present work, a thermophysical property characterization of aqueous solution of tris(hydroxymethyl)aminomethane (TRIS), a biological buffer, was done. The investigated properties were refractive index (n), density ({rho}), and electrolytic conductivity ({kappa}). These properties were measured for temperatures up to 353.15 K (at normal atmospheric condition) and for the entire composition range where TRIS is still soluble in water. The measured properties were reported as functions of temperature and composition. A modified form of the Vogel-Tamman-Fulcher equation which leads to an Arrhenius-type asymptotic exponential function was used to generally correlate the temperature and compositional dependence of the considered properties and satisfactory results were obtained.

  6. Comprehensive characterization of thermophysical properties in solids using thermal impedance

    Science.gov (United States)

    Martínez-Flores, J. J.; Licea-Jiménez, L.; Pérez García, S. A.; Rodríguez-Viejo, J.; Alvarez-Quintana, J.

    2012-11-01

    Thermal impedance Zth(iω) is a way of defining the thermophysical characteristics and behavior of thermal systems. Existing photoacoustic and photothermal approaches based on thermal impedance formalism merely allows a partial thermal characterization of the materials (generally, either thermal diffusivity or thermal effusivity). In this work, a new approach based on the thermal impedance concept in terms of its characteristic thermal time constant is developed from thermal quadrupoles formalism. The approach outlined in this contribution presents a set of analytical equations in which through a single measurement of thermal impedance is sufficient to obtain a comprehensive characterization of the thermophysical properties of solid materials in a simple way.

  7. Two-dimensional carbon fundamental properties, synthesis, characterization, and applications

    CERN Document Server

    Yihong, Wu; Ting, Yu

    2013-01-01

    After a brief introduction to the fundamental properties of graphene, this book focuses on synthesis, characterization and application of various types of two-dimensional (2D) nanocarbons ranging from single/few layer graphene to carbon nanowalls and graphene oxides. Three major synthesis techniques are covered: epitaxial growth of graphene on SiC, chemical synthesis of graphene on metal, and chemical vapor deposition of vertically aligned carbon nanosheets or nanowalls. One chapter is dedicated to characterization of 2D nanocarbon using Raman spectroscopy. It provides extensive coverage for a

  8. Synthesis, characterization and thermal properties of thiosalicylate ionic liquids

    Indian Academy of Sciences (India)

    Cecilia Devi Wilfred; Fadwa Babiker Mustafa

    2013-11-01

    In an attempt to produce new functionalized ionic liquids, a series of thiosalicylate ionic liquids based on imidazolium, ammonium, phosphonium, choline and pyrrolidinium cations were synthesized. The compounds were characterized by Infra Red (IR), Nuclear Magnetic Resonance (NMR) and mass spectra (ESI-MS). Their glass-transition temperatures, melting points and decomposition temperatures have been measured. Physicochemical properties of ionic liquids are influenced by alkyl chain length and nature of the cation of ionic liquids.

  9. Preparation, Characterization and Properties of Polymers Incorporating Spiro-centers

    OpenAIRE

    Shamsipour, Hosna

    2013-01-01

    This research aimed to develop new polymeric materials for use in membrane or adsorption processes for carbon dioxide capture. In particular, it explored the synthesis, characterization and properties of polymers incorporating a spiro-center. A dianhydride containing a spiro-center (An-1), suitable for use in the preparation of polyimides, was synthesized using a previously reported procedure. The spiro-center makes the structure of the resulting polymers (PIM-PIs) similar to polymers of intr...

  10. Synthesis, Properties Characterization and Applications of Various Organobismuth Compounds

    OpenAIRE

    Jingfei Luan; Zhitian Hu; Lingyan Zhang

    2011-01-01

    Organobismuth chemistry was emphasized in this review article due to the low price, low toxicity and low radioactivity characteristics of bismuth. As an environmentally-friendly class of organometallic compounds, different types of organobismuth compounds have been used in organic synthesis, catalysis, materials, etc. The synthesis and property characterization of many organobismuth compounds had been summarized. This review article also presented a survey of various applications of organobis...

  11. Robotic palpation and mechanical property characterization for abnormal tissue localization.

    Science.gov (United States)

    Ahn, Bummo; Kim, Yeongjin; Oh, Cheol Kyu; Kim, Jung

    2012-09-01

    Palpation is an intuitive examination procedure in which the kinesthetic and tactile sensations of the physician are used. Although it has been widely used to detect and localize diseased tissues in many clinical fields, the procedure is subjective and dependent on the experience of the individual physician. Palpation results and biomechanics-based mechanical property characterization are possible solutions that can enable the acquisition of objective and quantitative information on abnormal tissue localization during diagnosis and surgery. This paper presents an integrated approach for robotic palpation combined with biomechanical soft tissue characterization. In particular, we propose a new palpation method that is inspired by the actual finger motions that occur during palpation procedures. To validate the proposed method, robotic palpation experiments on silicone soft tissue phantoms with embedded hard inclusions were performed and the force responses of the phantoms were measured using a robotic palpation system. Furthermore, we carried out a numerical analysis, simulating the experiments and estimating the objective and quantitative properties of the tissues. The results indicate that the proposed approach can differentiate diseased tissue from normal tissue and can characterize the mechanical information of diseased tissue, which means that this method can be applied as a means of abnormality localization to diagnose prostate cancers. PMID:22772733

  12. Versatile magnetometer assembly for characterizing magnetic properties of nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, J. F. D. F.; Bruno, A. C.; Louro, S. R. W. [Department of Physics, Pontifícia Universidade Católica do Rio de Janeiro, Rio de Janeiro 22451-900 (Brazil)

    2015-10-15

    We constructed a versatile magnetometer assembly for characterizing iron oxide nanoparticles. The magnetometer can be operated at room temperature or inside a cryocooler at temperatures as low as 6 K. The magnetometer’s sensor can be easily exchanged and different detection electronics can be used. We tested the assembly with a non-cryogenic commercial Hall sensor and a benchtop multimeter in a four-wire resistance measurement scheme. A magnetic moment sensitivity of 8.5 × 10{sup −8} Am{sup 2} was obtained with this configuration. To illustrate the capability of the assembly, we synthesized iron oxide nanoparticles coated with different amounts of a triblock copolymer, Pluronic F-127, and characterized their magnetic properties. We determined that the polymer coating does not affect the magnetization of the particles at room temperature and demonstrates that it is possible to estimate the average size of coating layers from measurements of the magnetic field of the sample.

  13. Versatile magnetometer assembly for characterizing magnetic properties of nanoparticles

    International Nuclear Information System (INIS)

    We constructed a versatile magnetometer assembly for characterizing iron oxide nanoparticles. The magnetometer can be operated at room temperature or inside a cryocooler at temperatures as low as 6 K. The magnetometer’s sensor can be easily exchanged and different detection electronics can be used. We tested the assembly with a non-cryogenic commercial Hall sensor and a benchtop multimeter in a four-wire resistance measurement scheme. A magnetic moment sensitivity of 8.5 × 10−8 Am2 was obtained with this configuration. To illustrate the capability of the assembly, we synthesized iron oxide nanoparticles coated with different amounts of a triblock copolymer, Pluronic F-127, and characterized their magnetic properties. We determined that the polymer coating does not affect the magnetization of the particles at room temperature and demonstrates that it is possible to estimate the average size of coating layers from measurements of the magnetic field of the sample

  14. Synthesis, Characterization, and Electrochemical Properties of Polyaniline Thin Films

    Science.gov (United States)

    Rami, Soukaina

    Conjugated polymers have been used in various applications (battery, supercapacitor, electromagnetic shielding, chemical sensor, biosensor, nanocomposite, light-emitting-diode, electrochromic display etc.) due to their excellent conductivity, electrochemical and optical properties, and low cost. Polyaniline has attracted the researchers from all disciplines of science, engineering, and industry due to its redox properties, environmental stability, conductivity, and optical properties. Moreover, it is a polymer with fast electroactive switching and reversible properties displayed at low potential, which is an important feature in many applications. The thin oriented polyaniline films have been fabricated using self-assembly, Langmuir-Blodgett, in-situ self-assembly, layer-by-layer, and electrochemical technique. The focus of this thesis is to synthesize and characterize polyaniline thin films with and without dyes. Also, the purpose of this thesis is to find the fastest electroactive switching PANI electrode in different electrolytic medium by studying their electrochemical properties. These films were fabricated using two deposition techniques: in-situ self-assembly and electrochemical deposition. The characterization of these films was done using techniques such as Fourier Transform Infrared Spectroscopy (FTIR), UV-spectroscopy, Scanning Electron Microscope (SEM), and X-Ray Diffraction (XRD). FTIR and UV-spectroscopy showed similar results in the structure of the polyaniline films. However, for the dye incorporated films, since there was an addition in the synthesis of the material, peak locations shifted, and new peaks corresponding to these materials appeared. The 1 layer PANI showed compact film morphology, comparing to other PANI films, which displayed a fiber-like structure. Finally, the electrochemical properties of these thin films were studied using cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) in

  15. Synthesis, Properties Characterization and Applications of Various Organobismuth Compounds

    Directory of Open Access Journals (Sweden)

    Jingfei Luan

    2011-05-01

    Full Text Available Organobismuth chemistry was emphasized in this review article due to the low price, low toxicity and low radioactivity characteristics of bismuth. As an environmentally-friendly class of organometallic compounds, different types of organobismuth compounds have been used in organic synthesis, catalysis, materials, etc. The synthesis and property characterization of many organobismuth compounds had been summarized. This review article also presented a survey of various applications of organobismuth compounds in organic transformations, as reagents or catalysts. The reactivity, reaction pathways and mechanisms of reactions with organobismuths were discussed. Less common and limiting aspects of organobismuth compounds were also briefly mentioned.

  16. Characterization of electrical properties of resistance welding machines

    Institute of Scientific and Technical Information of China (English)

    Wu Pei; Shao Yingli; Wenqi Zhang; Niels Bay

    2008-01-01

    Due to the individual electrical and mechanical characteristics of resistance welding machines, choice of the right machine and welding parameters for an optimized production is often difficult. This is especially the case in projection welding of complex joints. In this paper, a new approach of characterizing the electrical properties of AC resistance welding machines is presented, involving testing and mathematical modelling of the weld current, the firing angle and the conduction angle of silicon controlled rectifiers with the aid of a series of proof resistances. The model predicts the weld current and the conduction angle (or heat setting) at each set current, when the workpiece resistance is given.

  17. Synthesis characterization, and properties of rubber lattices; a review

    International Nuclear Information System (INIS)

    Latex is a stable dispersion of polymeric material in an aqueous medium. Lattices are present in natural as well as in synthetic forms. The range of applications of latex is extensive in carpet underlay, fabric back-coating, paper and paints coatings, adhesive, binder, leather finish, floor polish, waterproof clothing, bounded fiber, pigment printing, latex thread, cement and asphalt, foam scraps binders, can closure, thickeners, box toes and shoes counters, sealant and mastics, modifiers, protein reduction, enzyme treatment and peroxide vulcanization. In this review we are presenting synthesis, characterization, properties, manufacturing and processing of latex. (author)

  18. CHARACTERIZATION AND PROPERTIES OF A LIGNOSULFONATE-BASED PHENOLIC FOAM

    Directory of Open Access Journals (Sweden)

    Lihong Hu,

    2011-11-01

    Full Text Available Phenolated lignosulfonate was introduced into the synthesis of phenolic resol with phenol and formaldehyde in an alkaline condition. The modified resol was successfully applied to prepare phenolic foam using appropriate combinations of flowing agents. N-pentane was found to be suitable as the foaming agent. Sulphuric acid (50% aqueous solution, w/w and Tween-80 were used as catalyst and surfactant, respectively. The obtained foams were characterized by thermogravimetric analysis (TGA, scanning electron microscopy (SEM, friability, and mechanical property tests. The experimental results showed the foam to have lower density, better toughness, and excellent thermal insulation compared to those of foams obtained from conventional resol resin. The properties of phenolated lignosulfonate modified phenolic foam can comply with the required specifications for its practical utilization.

  19. Characterization of an aluminum pillared montmorillonite with cation exchange properties

    International Nuclear Information System (INIS)

    The methods of PIGE and XRF were used to determine the elemental composition and the structural formulae of a specially tailored PILC material during the steps of its preparation. The CEC, a crucial property for the characterization of a cation exchanger, was monitored through all stages of preparation. In addition, the charge carried by the pillars, a critical quantity of the pillaring process, was estimated. Exchange isotherms of strontium and cesium were performed through the use of radiotracers' exchange isotherms of 137Cs and 85Sr with typical γ-ray spectroscopy. These isotherms were of the Langmuir type and PILCs adsorption capacity was determined. The latter property was compared with the CEC determined by the elemental analysis and was found equal to the amount of the exchangeable interlamellar sodium ions. (author)

  20. N-Methylmelamines: Synthesis, Characterization, and Physical Properties.

    Science.gov (United States)

    List, Manuela; Puchinger, Helmut; Gabriel, Herbert; Monkowius, Uwe; Schwarzinger, Clemens

    2016-05-20

    N-Methylmelamines have recently gained importance as valuable compounds for manufacturing modified melamine formaldehyde resins and other polymer building blocks. A great advantage of these polymers is the reduction of the carcinogenic formaldehyde. Selecting the polymerization processes (e.g., substance polymerization, polymerization in solution) and controlling the polymerization reaction and properties of these novel materials requires knowledge of the properties of the individual melamine derivatives used as new building blocks. All possible permutations of N-methylmelamines were prepared, and reaction progress was monitored by GC/MS. 2,4,6-Tris(dimethylamino)-1,3,5-triazine was prepared to complete the series; this is, however, also a possible byproduct in various synthesis routes. The reaction conditions were optimized to obtain high yields of each derivative with the highest possible purity. The substances were characterized by NMR and IR spectroscopy, mass spectrometry, elemental analysis, and single-crystal X-ray diffraction. In addition, physical properties, such as solubility, melting points, and pKb values, were determined. The number of amino-, methylamino-, and dimethylamino groups has a significant effect on these properties. In summary, we found that by increasing the number of amino- and methylamino groups, solubility and pKb increase. With increasing number of amino groups, the compounds tend to form hydrogen bonds, and thus, the melting point shifts to higher temperature ranges where they start to decompose. PMID:27100712

  1. Characterization of the electromechanical properties of EAP materials

    Science.gov (United States)

    Bar-Cohen, Yoseph; Sherrita, Stewart; Bhattachary, Kaushik; Lih, Shyh-Shiuh

    2001-01-01

    Electroactive polymers (EAP) are an emerging class of actuation materials. Their large electrically induced strains (longitudinal or bending), low density, mechanical flexibility, and ease of processing offer advantages over traditional electroactive materials. However, before the capability of these materials can be exploited, their electrical and mechanical behavior must be properly quantified. Two general types of EAP can be identified. The first type is ionic EAP, which requires relatively low voltages (materials requires large electric fields (>100MV/m) to achieve longitudinal deformations at the range from 4 - 360%. Some of the difficulties in characterizing EAP include: nonlinear properties, large compliance (large mismatch with metal electrodes), nonhomogeneity resulting from processing, etc. To support the need for reliable data, the authors are developing characterization techniques to quantify the electroactive responses and material properties of EAP materials. The emphasis of the current study is on addressing electromechanical issues related to the ion-exchange type EAP also known as IPMC. The analysis, experiments and test results are discussed in this paper.

  2. Analytical model for nanoscale viscoelastic properties characterization using dynamic nanoindentation

    Science.gov (United States)

    Yuya, Philip A.; Patel, Nimitt G.

    2014-08-01

    In the last few decades, nanoindentation has gained widespread acceptance as a technique for materials properties characterization at micron and submicron length scales. Accurate and precise characterization of material properties with a nanoindenter is critically dependent on the ability to correctly model the response of the test equipment in contact with the material. In dynamic nanoindention analysis, a simple Kelvin-Voigt model is commonly used to capture the viscoelastic response. However, this model oversimplifies the response of real viscoelastic materials such as polymers. A model is developed that captures the dynamic nanoindentation response of a viscoelastic material. Indenter tip-sample contact forces are modelled using a generalized Maxwell model. The results on a silicon elastomer were analysed using conventional two element Kelvin-Voigt model and contrasted to analysis done using the Maxwell model. The results show that conventional Kelvin-Voigt model overestimates the storage modulus of the silicone elastomer by ~30%. Maxwell model represents a significant improvement in capturing the viscoelastic material behaviour over the Voigt model.

  3. Electrical Property Characterization of Neural Stem Cells in Differentiation

    Science.gov (United States)

    Sun, He; Chen, Deyong; Li, Zhaohui; Fan, Beiyuan; George, Julian; Xue, Chengcheng; Cui, Zhanfeng; Wang, Junbo

    2016-01-01

    Electrical property characterization of stem cells could be utilized as a potential label-free biophysical approach to evaluate the differentiation process. However, there has been a lack of technology or tools that can quantify the intrinsic cellular electrical markers (e.g., specific membrane capacitance (Cspecific membrane) and cytoplasm conductivity (σcytoplasm)) for a large amount of stem cells or differentiated cells. In this paper, a microfluidic platform enabling the high-throughput quantification of Cspecific membrane and σcytoplasm from hundreds of single neural stem cells undergoing differentiation was developed to explore the feasibility to characterize the neural stem cell differentiation process without biochemical staining. Experimental quantification using biochemical markers (e.g., Nestin, Tubulin and GFAP) of neural stem cells confirmed the initiation of the differentiation process featured with gradual loss in cellular stemness and increased cell markers for neurons and glial cells. The recorded electrical properties of neural stem cells undergoing differentiation showed distinctive and unique patterns: 1) in the suspension culture before inducing differentiation, a large distribution and difference in σcytoplasm among individual neural stem cells was noticed, which indicated heterogeneity that may result from the nature of suspension culture of neurospheres; and 2) during the differentiation in adhering monolayer culture, significant changes and a large difference in Cspecific membrane were located indicating different expressions of membrane proteins during the differentiation process, and a small distribution difference in σcytoplasm was less significant that indicated the relatively consistent properties of cytoplasm during the culture. In summary, significant differences in Cspecific membrane and σcytoplasm were observed during the neural stem cell differentiation process, which may potentially be used as label-free biophysical markers

  4. Characterizing the nonlinear and dynamical properties of thermionic conversion

    Energy Technology Data Exchange (ETDEWEB)

    Irvin, A.D.; Tanner, P.; Fraser, D.; Dewson, T.

    1998-07-01

    The conversion process of thermal power to electrical power is represented as a mixed linear-nonlinear convolution form of the Onsager equations. A moment hierarchy method is presented that transforms the Volterra functional expansion into a linear algebraic form, which is trivial to invert. The method is nonparametric and can be used to estimate both the form and amplitude of the ascending order multivariate nonlinear response functions that characterize the conversion and transport processes from the discrete vector time data. A multi-channel input-output representation for causal thermal and electrical processes is discussed with reference to the physical significance of the estimated response function. This representation is then used to develop a multi-convolution percolation theory for coupled thermal electric processes in ceramic materials. In addition to the Volterra approach a numerical calculation procedure is being developed that can model the transport properties in both the electrodes and the inter-electrode plasma. The starting point for this is the plasma physics particle in a cell model KARAT. This simulation model is presently being validated against available empirical data and some provisional results are presented here. In order to design and understand the properties of ceramically coated electrodes that have thermodynamic forces acting to modify the generation and overall transport properties of the diode KARAT is being extended to include the nonlinear dynamic effects of combined temperature and species gradients in the electrode surface layers.

  5. BATMAN beam properties characterization by the beam emission spectroscopy diagnostic

    Science.gov (United States)

    Bonomo, F.; Ruf, B.; Barbisan, M.; Cristofaro, S.; Schiesko, L.; Fantz, U.; Franzen, P.; Pasqualotto, R.; Riedl, R.; Serianni, G.; Wünderlich, D.

    2015-04-01

    The ITER neutral beam heating systems are based on the production and acceleration of negative ions (H/D) up to 1 MV. The requirements for the beam properties are strict: a low core beam divergence (BATMAN (BAvarian Test MAchine for Negative ions) allows for deepening the knowledge of the determination of the beam properties. One of the diagnostics routinely used to this purpose is the Beam Emission Spectroscopy (BES): the Hα light emitted in the beam is detected and the corresponding spectra are evaluated to estimate the beam divergence and the stripping losses. The BES number of lines of sight in BATMAN has been recently increased: five horizontal lines of sight providing a vertical profile of the beam permit to characterize the negative ion beam properties in relation to the source parameters. Different methods of Hα spectra analysis are here taken into account and compared for the estimation of the beam divergence and the amount of stripping. In particular, to thoroughly study the effect of the space charge compensation on the beam divergence, an additional hydrogen injection line has been added in the tank, which allows for setting different background pressure values (one order of magnitude, from about 0.04 Pa up to the source pressure) in the beam drift region.

  6. Fabrication, characterization, and thermal property evaluation of silver nanofluids

    Science.gov (United States)

    Noroozi, Monir; Radiman, Shahidan; Zakaria, Azmi; Soltaninejad, Sepideh

    2014-11-01

    Silver nanoparticles were successfully prepared in two different solvents using a microwave heating technique, with various irradiation times. The silver nanoparticles were dispersed in polar liquids (distilled water and ethylene glycol) without any other reducing agent, in the presence of the stabilizer polyvinylpyrrolidone (PVP). The optical properties, thermal properties, and morphology of the synthesized silver particles were characterized using ultraviolet-visible spectroscopy, photopyroelectric technique, and transmission electron microscopy. It was found that for the both solvents, the effect of microwave irradiation was mainly on the particles distribution, rather than the size, which enabled to make stable and homogeneous silver nanofluids. The individual spherical nanostructure of self-assembled nanoparticles has been formed during microwave irradiation. Ethylene glycol solution, due to its special properties, such as high dielectric loss, high molecular weight, and high boiling point, can serve as a good solvent for microwave heating and is found to be a more suitable medium than the distilled water. A photopyroelectric technique was carried out to measure thermal diffusivity of the samples. The precision and accuracy of this technique was established by comparing the measured thermal diffusivity of the distilled water and ethylene glycol with values reported in the literature. The thermal diffusivity ratio of the silver nanofluids increased up to 1.15 and 1.25 for distilled water and ethylene glycol, respectively.

  7. BATMAN beam properties characterization by the beam emission spectroscopy diagnostic

    International Nuclear Information System (INIS)

    The ITER neutral beam heating systems are based on the production and acceleration of negative ions (H/D) up to 1 MV. The requirements for the beam properties are strict: a low core beam divergence (< 0.4 °) together with a low source pressure (≤ 0.3 Pa) would permit to reduce the ion losses along the beamline, keeping the stripping particle losses below 30%. However, the attainment of such beam properties is not straightforward. At IPP, the negative ion source testbed BATMAN (BAvarian Test MAchine for Negative ions) allows for deepening the knowledge of the determination of the beam properties. One of the diagnostics routinely used to this purpose is the Beam Emission Spectroscopy (BES): the Hα light emitted in the beam is detected and the corresponding spectra are evaluated to estimate the beam divergence and the stripping losses. The BES number of lines of sight in BATMAN has been recently increased: five horizontal lines of sight providing a vertical profile of the beam permit to characterize the negative ion beam properties in relation to the source parameters. Different methods of Hα spectra analysis are here taken into account and compared for the estimation of the beam divergence and the amount of stripping. In particular, to thoroughly study the effect of the space charge compensation on the beam divergence, an additional hydrogen injection line has been added in the tank, which allows for setting different background pressure values (one order of magnitude, from about 0.04 Pa up to the source pressure) in the beam drift region

  8. BATMAN beam properties characterization by the beam emission spectroscopy diagnostic

    Energy Technology Data Exchange (ETDEWEB)

    Bonomo, F., E-mail: federica.bonomo@igi.cnr.it [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy); Istituto Gas Ionizzati - CNR, Corso Stati Uniti 4, 35127 Padova (Italy); Ruf, B.; Schiesko, L.; Fantz, U.; Franzen, P.; Riedl, R.; Wünderlich, D. [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany); Barbisan, M.; Pasqualotto, R.; Serianni, G. [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy); Cristofaro, S. [Universitá degli Studi di Padova, Via 8 Febbraio 2, 35122 Padova (Italy)

    2015-04-08

    The ITER neutral beam heating systems are based on the production and acceleration of negative ions (H/D) up to 1 MV. The requirements for the beam properties are strict: a low core beam divergence (< 0.4 °) together with a low source pressure (≤ 0.3 Pa) would permit to reduce the ion losses along the beamline, keeping the stripping particle losses below 30%. However, the attainment of such beam properties is not straightforward. At IPP, the negative ion source testbed BATMAN (BAvarian Test MAchine for Negative ions) allows for deepening the knowledge of the determination of the beam properties. One of the diagnostics routinely used to this purpose is the Beam Emission Spectroscopy (BES): the H{sub α} light emitted in the beam is detected and the corresponding spectra are evaluated to estimate the beam divergence and the stripping losses. The BES number of lines of sight in BATMAN has been recently increased: five horizontal lines of sight providing a vertical profile of the beam permit to characterize the negative ion beam properties in relation to the source parameters. Different methods of H{sub α} spectra analysis are here taken into account and compared for the estimation of the beam divergence and the amount of stripping. In particular, to thoroughly study the effect of the space charge compensation on the beam divergence, an additional hydrogen injection line has been added in the tank, which allows for setting different background pressure values (one order of magnitude, from about 0.04 Pa up to the source pressure) in the beam drift region.

  9. Characterization of positronium properties in doped liquid scintillators

    Science.gov (United States)

    Consolati, G.; Franco, D.; Hans, S.; Jollet, C.; Meregaglia, A.; Perasso, S.; Tonazzo, A.; Yeh, M.

    2013-12-01

    Orthopositronium (o-Ps) formation and decay can replace the annihilation process, when a positron interacts in liquid scintillator media. The delay induced by the positronium decay represents either a potential signature for antineutrino detection, via inverse β decay, or to identify and suppress positron background, as recently demonstrated by the Borexino experiment. The formation probability and decay time of o-Ps depend strongly on the surrounding material. In this paper, we characterize the o-Ps properties in liquid scintillators as function of concentrations of gadolinium, lithium, neodymium, and tellurium dopers used by present and future neutrino experiments. In particular, gadolinium and lithium are high neutron cross section isotopes, widely used in reactor antineutrino experiments, while neodymium and tellurium are double β decay emitters, employed to investigates the Majorana neutrino nature. Future neutrino experiments may profit from the performed measurements to tune the preparation of the scintillator in order to maximize the o-Ps signature, and therefore the discrimination power.

  10. Characterization of positronium properties in doped liquid scintillators

    CERN Document Server

    Consolati, G; Hans, S; Jollet, C; Meregaglia, A; Perasso, S; Tonazzo, A; Yeh, M

    2013-01-01

    Ortho-positronium (o-Ps) formation and decay can replace the annihilation process, when positron interacts in liquid scintillator media. The delay induced by the positronium decay represents either a potential signature for anti-neutrino detection, via inverse beta decay, or to identify and suppress positron background, as recently demonstrated by the Borexino experiment. The formation probability and decay time of o-Ps depend strongly on the surrounding material. In this paper, we characterize the o-Ps properties in liquid scintillators as function of concentrations of gadolinium, lithium, neodymium, and tellurium, dopers used by present and future neutrino experiments. In particular, gadolinium and lithium are high neutron cross section isotopes, widely used in reactor anti-neutrino experiments, while neodymium and tellurium are double beta decay emitters, employed to investigates the Majorana neutrino nature. Future neutrino experiments may profit from the performed measurements to tune the preparation of ...

  11. Characterization of structure and thermophysical properties of three ESR slags

    Science.gov (United States)

    Plotkowski, A.; deBarbadillo, J.; Krane, Matthew J. M.

    2016-07-01

    The structure and properties of electroslag remelting (ESR) slags were characterized. Slags samples of three compositions were obtained from industrial remelting processes at Special Metals Corporation and from casting in a laboratory vacuum induction melter. The structure of the slag samples was observed using optical and electron microscopy, and phases were identified and their relative amounts quantified using X-ray diffraction. Laser flash thermal diffusivity, density, and differential scanning calorimetry measurements for specific heat were performed to determine the bulk thermal conductivity of the samples. Sample porosity was measured as a function of depth using a serial sectioning technique, and a onedimensional computational model was developed to estimate the thermal conductivity of the fully dense slags. These results are discussed in context with previous studies, and opportunities for future research are identified. AFRL Case Number: 88ABW-2015-1871.

  12. Characterizing Properties and Performance of 3D Printed Plastic Scintillators

    Science.gov (United States)

    McCormick, Jacob

    2015-10-01

    We are determining various characteristics of the performance of 3D printed scintillators. A scintillator luminesces when an energetic particle raises electrons to an excited state by depositing some of its energy in the atom. When these excited electrons fall back down to their stable states, they emit the excess energy as light. We have characterized the transmission spectrum, emission spectrum, and relative intensity of light produced by 3D printed scintillators. We are also determining mechanical properties such as tensile strength and compressibility, and the refractive index. The emission and transmission spectra were measured using a monochromator. By observing the transmission spectrum, we can see which optical wavelengths are absorbed by the scintillator. This is then used to correct the emission spectrum, since this absorption is present in the emission spectrum. Using photomultiplier tubes in conjunction with integration hardware (QDC) to measure the intensity of light emitted by 3D printed scintillators, we compare with commercial plastic scintillators. We are using the characterizations to determine if 3D printed scintillators are a viable alternative to commercial scintillators for use at Jefferson Lab in nuclear and accelerated physics detectors. I would like to thank Wouter Deconinck, as well as the Parity group at the College of William and Mary for all advice and assistance with my research.

  13. Characterization and Physicochemical Properties of Condensed Tannins from Acacia catechu.

    Science.gov (United States)

    Duval, Antoine; Avérous, Luc

    2016-03-01

    Condensed tannins from Acacia catechu were carefully studied to determine their chemical structure and physicochemical properties. The combined use of MALDI-TOF-MS and (13)C NMR revealed that catechin and epicatechin are the predominant monomers. Most of the compounds were dimers, as confirmed by size exclusion chromatography measurements. To evaluate their potential as aromatic building block in polymer synthesis, special care was given to the characterization and quantification of the different OH groups. A detailed (31)P NMR analysis showed the predominance of catechin, with a catechin/epicatechin ratio of 4.2:1. Two distinct (1)H NMR measurements confirmed the quantification. The thermal properties were also determined: the tannins showed a high temperature of degradation (ca. 190 °C) and a high glass transition temperature (ca. 140 °C), allowing for thermal processing or chemical reactions at relatively high temperature. A. catechu tannins thus present interesting features to be used as aromatic building blocks in polymer materials. PMID:26853705

  14. Preparation, Characterization and Antibacterial Property of Cerium Substituted Hydroxyapatite Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Lin Yingguang; Yang Zhuoru; Cheng Jiang

    2007-01-01

    Nanoparticles of hydroxyapatite (HAP) and cerium substituted hydroxyapatite (CeHAP) with the atomic ratio of Ce/[Ca+Ce] (xCe) from 0 to 0.2 were prepared by sol-gel-supercritical fluid drying (SCFD) method. The nanoparticles were characterized by TEM, XRD, and FT-IR, and the effects of cerium on crystal structure, crystallinity, and particle shape were discussed. With the tests of bacterial inhibition zone and antibacterial ratio, the antibacterial property of HAP and CeHAP nanoparticles on Escherichia coli, Staphylococcus aureus, Lactobacillus were researched. Results showed that the nanoparticles of HAP and CeHAP could be made by sol-gel-SCFD, cerium could partially substitute for calcium and enter the structure of HAP. After substitution, the crystallinity, the IR wavenumbers of bonds in CeHAP decreased gradually with increase of cerium substitution, and the morphology of the nanoparticles changed from the short rod-shaped HAP to the needle-shaped CeHAP. The nanoparticles of HAP and CeHAP with xCe below 0.08 had antibacterial property only forcibly contacting with the test bacteria at the test concentration of 0.1 g·ml-1, however, the CeHAP nanoparticles had antibacterial ability at that concentration no matter statically or dynamically contacting with the test bacteria when xCe was above 0.08, and the antibacterial ability gets better with the increase of xCe, indicating that the antibacterial property was improved after calcium was partially substituted by cerium. The improved antibacterial effects of CeHAP nanoparticle on Lactobacillus showed its potential ability to anticaries.

  15. Multiscale characterization of porous media properties for hydrocarbon reservoir simulation

    Science.gov (United States)

    Neeman, Henry; Lao, Hio-Wai; Simpson, Dale; Papavassiliou, Dimitrios V.

    2001-07-01

    Fluid flow through porous materials is critical for understanding and predicting the behavior of systems as diverse in function and scale as hydrocarbon reservoirs, aquifers, filters, membrane separators and even catalytic converters. Recently, there have been calls to incorporate more physics in oil reservoir simulations, as well as to enhance computational capability through the use of High Performance Computing (HPC), in order to improve reservoir management. Accurate prediction of reservoir behavior depends on the physical properties of not only the fluid but also the underlying rock formation. Contemporary approaches to solving these flows involve simulation of only a single physical scale. We are currently developing HiMuST (Hierarchical Multiscale Simulator Technology), an integrated multiscale simulation system for flow through heterogeneous porous materials. HiMuST uses a hierarchy of simulation codes to address the issue of rock property characterization at the pore scale and can self-adjust according to available input data. At the microscopic scale, HiMuST employs the Lattice Boltzmann Method, based on magnetic resonance digitizations of actual rock samples. At the mesoscopic scale, a stochastic model represents a pore network as a randomly generated skeleton of cylindrical pipes, based on physical characteristics determined by the microscopic simulation. We present computational and computer science issues involved in the HPC implementation of the codes and in integrating them into a seamless simulation system. Issues such as portability, scalability, efficiency and extensibility of the final product are also discussed, as well as the numerical methods implemented at each scale. Example simulation results are presented.

  16. The role of structure-to-property-relationships in materials characterization

    Energy Technology Data Exchange (ETDEWEB)

    Morgner, W.

    2000-07-01

    The paper deals with questions concerning the material characterization for steels in the field of engineering and metallurgy. Based on the structure-to-property-relationships, a procedure is proposed to strengthen the systematical development of methods for nondestructive characterization of materials. The state of the nondestructive characterization of metals is reviewed and applications are described in which adequate macroscopic physical properties are measured in order to characterize the materials state and properties nondestructively. The materials characterization of ball bearing steel and cast iron using multiparametrical approaches is discussed in detail.

  17. Transition metal borides. Synthesis, characterization and superconducting properties

    International Nuclear Information System (INIS)

    A systematic study was done on the synthesis and superconducting properties of metal rich transition metal borides. Five different binary systems were investigated including the boride systems of niobium, tantalum, molybdenum, tungsten and rhenium. High temperature solid state methods were used in order to synthesize samples of different transition metal borides of the composition M2B, MB, M3B2, MB2, and M2B4. The reactions were carried out in three different furnaces with different sample containers: the electric arc (copper crucible), the high frequency induction furnace (boron nitride, tantalum or glassy carbon crucibles), and the conventional tube furnace (sealed evacuated quartz ampoules). The products obtained were characterized with X-ray powder diffractometry, scanning electron microscopy and energy-dispersive X-ray spectroscopy. Phase analyses and crystal structure refinements using the Rietveld method and based on structure models known from literature were performed. A neutron diffraction measurement was done for W2B4 to allow for a complete crystal structure determination, because of the presence of a heavy element like tungsten and a light element like boron that made it difficult to determine the accurate determination of the boron atom positions and occupancies from X-ray data. A new structure model for W2B4 was proposed. Magnetic measurements in a SQUID magnetometer down to temperatures as low as 1.8 K were performed to several of the products in order to see if the transition metal borides become superconducting at low temperatures, and the results were compared with data from literature. Superconducting properties were found for the following compounds: NbB2 (TC = 3.5 K), β-MoB (TC = 2.4 K), β-WB (TC = 2.0 K), α-WB (TC = 4.3 K), W2B4 (TC = 5.4 K), Re7B3 (TC = 2.4 K). A relationship between the superconducting properties and the compositional and structural features was discussed for metal diborides. Also it was found that there is an influence

  18. Synthesis, characterization, and electrical properties studies of cadmium selenide nanoparticle

    Science.gov (United States)

    Seoudi, R.; Elokr, M. M.; Shabaka, A. A.; Sobhi, A.

    2008-01-01

    A new solvothermal route was used for the preparation of CdSe nanoparticles at 160 °C for 10 h using ethylenediamine as a solvent. X-ray powder diffraction and transmission electron microscope were employed to characterize the size, morphology, and crystalline structure of the as-prepared sample. The formation process was discussed and it revealed a uniform hexagonal shape of CdSe nanoparticle with good dispersion, with an average size of 35 nm. Fourier transform infrared and ultraviolet-visible spectroscopies were used to follow the reaction and to determine the optical band gap. DC and AC electrical conductivities were studied and the activation energies were determined as well as the conduction mechanism. The results indicated that CdSe behaves as a semiconducting material. The dielectric properties were measured as a function of temperature at different frequencies ranging from 100 Hz to 100 kHz. The increase of the dielectric constant with increasing temperature was discussed on the basis of increasing polarizability, while its decrease with increasing frequency is attributed to the dielectric dispersion.

  19. Synthesis, characterization, and electrical properties studies of cadmium selenide nanoparticle

    International Nuclear Information System (INIS)

    A new solvothermal route was used for the preparation of CdSe nanoparticles at 160 deg. C for 10 h using ethylenediamine as a solvent. X-ray powder diffraction and transmission electron microscope were employed to characterize the size, morphology, and crystalline structure of the as-prepared sample. The formation process was discussed and it revealed a uniform hexagonal shape of CdSe nanoparticle with good dispersion, with an average size of 35 nm. Fourier transform infrared and ultraviolet-visible spectroscopies were used to follow the reaction and to determine the optical band gap. DC and AC electrical conductivities were studied and the activation energies were determined as well as the conduction mechanism. The results indicated that CdSe behaves as a semiconducting material. The dielectric properties were measured as a function of temperature at different frequencies ranging from 100 Hz to 100 kHz. The increase of the dielectric constant with increasing temperature was discussed on the basis of increasing polarizability, while its decrease with increasing frequency is attributed to the dielectric dispersion

  20. Synthesis, characterization and gas sensing property of hydroxyapatite ceramic

    Indian Academy of Sciences (India)

    M P Mahabole; R C Aiyer; C V Ramakrishna; B Sreedhar; R S Khairnar

    2005-10-01

    Hydroxyapatite (HAp) biomaterial ceramic was synthesized by three different processing routes viz. wet chemical process, microwave irradiation process, and hydrothermal technique. The synthesized ceramic powders were characterized by SEM, XRD, FTIR and XPS techniques. The dielectric measurements were carried out as a function of frequency at room temperature and the preliminary study on CO gas sensing property of hydroxyapatite was investigated. The XRD pattern of the hydroxyapatite biomaterial revealed that hydroxyapatite ceramic has hexagonal structure. The average crystallite size was found to be in the range 31–54 nm. Absorption bands corresponding to phosphate and hydroxyl functional groups, which are characteristic of hydroxyapatite, were confirmed by FTIR. The dielectric constant was found to vary in the range 9–13 at room temperature. Hydroxyapatite can be used as CO gas sensor at an optimum temperature near 125°C. X-ray photoelectron spectroscopic studies showed the Ca/P ratio of 1.63 for the HAp sample prepared by chemical process. The microwave irradiation technique yielded calcium rich HAp whereas calcium deficient HAp was obtained by hydrothermal method.

  1. Physical property characterization of a damage zone in granitic rock - Implications for geothermal reservoir properties

    Science.gov (United States)

    Wenning, Quinn; Madonna, Claudio; Amann, Florian; Gischig, Valentin; Burg, Jean-Pierre

    2016-04-01

    Geothermal energy offers a viable alternative to mitigate greenhouse gas emitting energy production. A tradeoff between less expensive drilling costs and increased permeability at shallow depths versus increased heat production at deeper depths stipulates the economic energy potential of a given reservoir. From a geological perspective, successful retrieval of geothermal energy from the subsurface requires sufficient knowledge of the structural and stratigraphic relationship of the target formations, which govern the thermal conditions, physical properties, and fluid flow properties of reservoir rocks. In Switzerland, deep basement rocks (~5 km) with fluid conducting damage zones and enhanced fractured systems stimulated by hydraulic shearing are seen as a potential geothermal reservoir system. Damage zones, both natural and induced, provide permeability enhancement that is especially important for creating fluid conductivity where the matrix permeability is low. This study concentrates on characterizing the elastic and transport properties entering into a natural damage zone penetrated by a borehole at the Grimsel underground research laboratory. The borehole drilled from a cavern at 480 m below ground surface penetrates approximately 20 m of mostly intact Grimsel granodiorite before entering the first phyllosilicate-rich shear zone (~0.2 m thick). The borehole intersects a second shear zone at approximately 23.8m. Between the two shear zones the Grimsel granodiorite is heavily fractured. The minimum principle stress magnitude from in-situ measurements decreases along the borehole into the first shear zone. Two mutually perpendicular core samples of Grimsel granodiorite were taken every 0.1 m from 19.5 to 20.1 m to characterize the physical properties and anisotropy changes as a gradient away from the damage zone. Measurements of ultrasonic compressional (Vp) and shear (Vs) velocities at 1 MHz frequency are conducted at room temperature and hydrostatic pressures

  2. Vanadium oxide based materials: Synthesis, characterization and gas sensing properties

    Science.gov (United States)

    Ayesh, Samar I.

    In recent years, the demand for gas sensors based on safety and process control requirements has been expanding. The reason for such demand sterns from environmental and safety concerns since the toxic gases released from automobile exhausts and chemical plants can directly or indirectly pollute our environment and affect our health. Among the chemicals studied, nitrogen oxide (NOx) gases are among the most dangerous air pollutants. Transition metal oxide clusters (or polyoxometalates) provide an exciting opportunity for the design and synthesis of a new generation of materials for efficient NOx sensing. Polyoxometalates are an important and fast emerging class of compounds that exhibit many remarkable properties. Chapter 1 provides introduction and background of chemical sensors. It describes the need for gas sensors and the current status of research in the area of NOx gas sensors in particular. A description of polyoxmetalates and their relevance as potential novel gas sensor materials is also given. Chapter 2 describes the synthesis and characterization by FTIR spectroscopy, elemental analysis, thermogravimetric analysis, manganometric titration, bond valence sum calculation, temperature dependent magnetic properties studies, electron paramagnetic resonance, and complete single crystal X-ray diffraction analysis of newly prepared vanadium oxide based-systems that have been discovered during the course of this work. First, the system containing arrays of decavanadates networked by extensive hydrogen bonding with cyclic nitrogen bases are described. This is followed by the mixed-valence vanadium oxide cluster, [VV 13VIV3O42(Cl)]-7, containing a hitherto unknown vanadium oxide framework structure. Finally the synthesis of 3D-framework materials is described. These compounds have highly symmetrical closely related three-dimensional framework structures consisting vanadium oxide shells {V18O42(XO4)} linked via heterometallic atoms {M' = Cd, Zn} into three

  3. Optical characterization of OLED emitter properties by radiation pattern analyses

    Energy Technology Data Exchange (ETDEWEB)

    Flaemmich, Michael

    2011-09-08

    Researches in both, academia and industry are investigating optical loss channels in OLED layered systems by means of optical simulation tools in order to derive promising concepts for a further enhancement of the overall device performance. Besides other factors, the prospects of success of such optimization strategies rely severely on the credibility of the optical input data. The present thesis provides a guideline to measure the active optical properties of OLED emitter materials in situ by radiation pattern analyses. Reliable and widely applicable methods are introduced to determine the internal electroluminescence spectrum, the profile of the emission zone, the dipole emitter orientation, and the internal luminescence quantum efficiency of emissive materials from the optical far field emission of OLEDs in electrical operation. The proposed characterization procedures are applied to sets of OLEDs containing both, fluorescent polymeric materials as well as phosphorescent small-molecular emitters, respectively. On the one hand, quite expected results are obtained. On the other hand, several novel and truly surprising results are found. Most importantly, this thesis contains the first report of a non-isotropic, mainly parallel emitter orientation in a phosphorescent small-molecular guest-host system (Ir(MDQ)2(acac) in a-NPD). Due to the latter result, emitter orientation based optimization of phosphorescent OLEDs seems to be within reach. Since parallel dipoles emit preferably into air, the utilization of smart emissive materials with advantageous molecular orientation is capable to boost the efficiency of phosphorescent OLEDs by 50%. Materials design, the influence of the matrix material and the substrate, as well as film deposition conditions are just a few parameters that need to be studied further in order to exploit the huge potential of the dipole emitter orientation in phosphorescent OLEDs.

  4. Characterization and electrical properties of chitosan for waste water treatment

    Science.gov (United States)

    Saengkaew, Phannee; Chantanachai, Kanittha; Cheewajaroen, Kulthawat; Nimsiri, Woraporn

    2016-05-01

    Chitosan extracted from shrimp shell waste was characterized in order to use for the industrial wastewater treatment. By XRF technique, the qualitative and semi-quantitative analyses of pure chitosan were performed with the relative compositions of Ca, Mg, Si, Fe, Al, and Na of 0.321%, 0.738%, 0.713%, 0.363%, 0.338%, and 3.858%, respectively. In the case of two types of the contaminated chitosan from the wastewater treatment before and after a process of a primary H2O2-treatment, the relative compositions of Ca, Mg, Si and Fe were obtained with an increasing of 0.356%, 1.321%, 1.536%, 0.451% and 0.406%, 1.105%, 1.178%, 0.591%, respectively. This shows that the suspended materials in the wastewater were absorbed by chitosan. By I-V Measurements, the across-through voltage of the pure chitosan disc was 0.245V±0.053 at the applied voltage of 17V, and resistance of 53.9MΩ ±10.3 at the applied voltage of 590V. After the utilization for the wastewater treatment, the across voltage of chitosan discs from two cases were 0.133V±0.047 and 0.223V±0.063, and the resistance of 122.8MΩ ±16.1 and 24.8MΩ ±5.1. The used chitosan has a lower conductivity because of a decreasing in the chitosan's electrical dipoles by combining with the suspended ions in the wastewater. Moreover, the adsorption efficiencies of chitosan for formaldehyde in the wastewater of two cases were 31.08% and 25.40%. In summary, chitosan is efficiently utilized in the wastewater treatment by absorption of the suspended materials and formaldehyde due to its molecular structure providing a good electrical property.

  5. Characterization of Different Parts of Oil Palm Fronds (Elaeis Guineensis) and Its Properties

    OpenAIRE

    Noor Afeefah Nordin; Othman Sulaiman; Rokiah Hashim; Mohamad Haafiz Mohamad Kassim

    2016-01-01

    The study was conducted on characterizing the properties of oil palm fronds (Elaeis guineensis) from different parts. The fronds were cut to three parts which were the top, middle and bottom. The samples were chipped, dried in the oven of 50 °C and ground before they were characterized. The properties of the fronds were characterized using thermal gravimetric analyser (TGA), fourier transform infrared spectroscopy (FTIR) and x-ray diffraction (XRD). The results from TGA showed that the bottom...

  6. The Characterization of the Magnetic Properties of Soft Magnetic Materials

    DEFF Research Database (Denmark)

    Larsen, Raino Michael

    1996-01-01

    The hysteresis curve and magnetic properties such as permeability, saturation induction, residual induction, coercive force and hysteresis losses are presented. The design and construction of equipment making it possible to measure true DC-values as well as AC-properties of toroid rings and...

  7. Montmorillonite polyaniline nanocomposites: Preparation, characterization and investigation of mechanical properties

    International Nuclear Information System (INIS)

    The interest in clay polymer nanocomposites (CPN) materials, initially developed by researchers at Toyota, has grown dramatically over the last decade. They have attracted great interest, both in industry and in academia, because they often exhibit remarkable improvement in materials' properties when compared with virgin polymer or conventional micro- and macro-composites. These improvements can include high moduli, increased strength and heat resistance, decreased gas permeability and flammability, optical transparency and increased biodegradability of biodegradable polymers. Such enhancement in the properties of nanocomposites occurs mostly due to their unique phase morphology and improved interfacial properties. Because of these enhanced properties they find applications in the fields of electronics, automobile industry, packaging, and construction. This study aims at investigating the mechanical property enhancement of polyaniline (PANI) intercalated with montmorillonite (MMT) clay. The MMT-PANI nanocomposites displayed improved mechanical properties compared to the neat polymer or clay. The enhancement was achieved at low clay content probably due to its exfoliated structure. The increased interfacial areas and improved bond characteristics may attribute to the mechanical property enhancement

  8. Working with the NCL - Intellectual Property - Nanotechnology Characterization Laboratory

    Science.gov (United States)

    To share and safeguard Research Material, intellectual property and proprietary information, the NCL's interaction with extramural researchers and vendors will normally be conducted under a Material Transfer Agreement (MTA).

  9. Microstructure characterization and magnetic properties of nano structured materials

    Energy Technology Data Exchange (ETDEWEB)

    Sun, X.C

    2000-07-01

    The present thesis deals with the unique microstructural properties and their novel magnetic properties of core-shell Ni-Ce nano composite particles, carbon encapsulated Fe, Co, and Ni nanoparticles and the nano crystallization behavior of typical ferromagnetic Fe{sub 78}Si{sub 9}B{sub 13} ribbons. These properties have intensively been investigated by high resolution transmission electron microscopy (HREM), X-ray diffraction (XRD), scanning electron microscopy (Sem), X-ray energy dispersive spectroscopy [eds.]; selected area electron diffraction pattern (SAED), Ft-IR, differential scanning calorimeter (DSC). In addition, magnetic moments measurements at different temperatures and applied fields have been performed by transmission Moessbauer spectroscopy, superconducting quantum interference device magnetometer (SQUID), and vibrating sample magnetometer (VSM). The present studies may provide the insights for the better understanding of the correlation between the unique microstructure and novel magnetic properties for several magnetic nano structured materials. (Author)

  10. Microstructure characterization and magnetic properties of nano structured materials

    International Nuclear Information System (INIS)

    The present thesis deals with the unique microstructural properties and their novel magnetic properties of core-shell Ni-Ce nano composite particles, carbon encapsulated Fe, Co, and Ni nanoparticles and the nano crystallization behavior of typical ferromagnetic Fe78Si9B13 ribbons. These properties have intensively been investigated by high resolution transmission electron microscopy (HREM), X-ray diffraction (XRD), scanning electron microscopy (Sem), X-ray energy dispersive spectroscopy (Eds.); selected area electron diffraction pattern (SAED), Ft-IR, differential scanning calorimeter (DSC). In addition, magnetic moments measurements at different temperatures and applied fields have been performed by transmission Moessbauer spectroscopy, superconducting quantum interference device magnetometer (SQUID), and vibrating sample magnetometer (VSM). The present studies may provide the insights for the better understanding of the correlation between the unique microstructure and novel magnetic properties for several magnetic nano structured materials. (Author)

  11. Using geophysical techniques to characterize tillage effect on soil properties

    OpenAIRE

    Jonard, Francois; Mahmoudzadeh,; Roisin,; Weihermüller, Lutz; Andre, Frederic; Vereecken, Harry; S. Lambot

    2012-01-01

    Tillage practices influence physical, chemical, and biological soil properties, which also affect soil quality and consequently plant growth. In this study, the main objective was to evaluate the effect of different tillage systems on soil physical properties by using geophysical methods, namely, ground-penetrating radar (far-field and near-field GPR), capacitance probes (ThetaProbe and 5TE), electromagnetic induction (EMI) (Profiler and EM38), soil sampling, and by soil penetrometer. Since 2...

  12. Characterization of physicochemical properties of ivy nanoparticles for cosmetic application

    OpenAIRE

    Huang Yujian; Lenaghan Scott C; Xia Lijin; Burris Jason N; Stewart C Neal Jr; Zhang Mingjun

    2013-01-01

    Abstract Background Naturally occurring nanoparticles isolated from English ivy (Hedera helix) have previously been proposed as an alternative to metallic nanoparticles as sunscreen fillers due to their effective UV extinction property, low toxicity and potential biodegradability. Methods This study focused on analyzing the physicochemical properties of the ivy nanoparticles, specifically, those parameters which are crucial for use as sunscreen fillers, such as pH, temperature, and UV irradia...

  13. Characterization of adhesively bonded joints using bulk adhesive properties

    OpenAIRE

    Kon, Haruhiko

    1991-01-01

    Though using bulk adhesive properties to predict adhesively bonded joint response has yet to be proven infallible, based upon the success of previous works, this effort attempts to shed some light on the stresses present in a typical automotive bonded joint. Adhesive material properties obtained in previous works were used in a finite element analysis of a simulated automotive joint to predict the stresses in that joint. The automotive joint analyzed was a simplified repr...

  14. Synthesis, characterization and photophysical properties of ESIPT reactive triazine derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Kuplich, Marcelo D.; Grasel, Fabio S.; Campo, Leandra F.; Rodembusch, Fabiano S.; Stefani, Valter, E-mail: vstefani@iq.ufrgs.br [Laboratorio de Novos Materiais Organicos. Instituto de Quimica. Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil)

    2012-07-01

    Four new reactive fluorescent triazine derivatives were obtained from nucleophilic aromatic substitution of cyanuric chloride. The compounds were characterized by infrared spectroscopy (IR), nuclear magnetic resonance ({sup 13}C and {sup 1}H NMR) and high resolution mass spectrometry (HRMS MALDI). UV-Vis and steady-state fluorescence (in solution and in solid state) spectroscopies were also applied to characterize the photophysical behavior. The dyes are fluorescent by an intramolecular proton transfer mechanism (ESIPT) in the blue-orange region, with a large Stokes shift between 6365-10290 cm-1. The fluorescent cyanuric derivatives could successfully react with cellulose fibers to give new fluorescent cellulosic materials. (author)

  15. Synthesis, characterization and photophysical properties of ESIPT reactive triazine derivatives

    International Nuclear Information System (INIS)

    Four new reactive fluorescent triazine derivatives were obtained from nucleophilic aromatic substitution of cyanuric chloride. The compounds were characterized by infrared spectroscopy (IR), nuclear magnetic resonance (13C and 1H NMR) and high resolution mass spectrometry (HRMS MALDI). UV-Vis and steady-state fluorescence (in solution and in solid state) spectroscopies were also applied to characterize the photophysical behavior. The dyes are fluorescent by an intramolecular proton transfer mechanism (ESIPT) in the blue-orange region, with a large Stokes shift between 6365-10290 cm-1. The fluorescent cyanuric derivatives could successfully react with cellulose fibers to give new fluorescent cellulosic materials. (author)

  16. Classification of analysis methods for characterization of magnetic nanoparticle properties

    DEFF Research Database (Denmark)

    Posth, O.; Hansen, Mikkel Fougt; Steinhoff, U.;

    2015-01-01

    The aim of this paper is to provide a roadmap for the standardization of magnetic nanoparticle (MNP) characterization. We have assessed common MNP analysis techniques under various criteria in order to define the methods that can be used as either standard techniques for magnetic particle charact...

  17. Barium titanate inverted opals-synthesis, characterization, and optical properties

    Energy Technology Data Exchange (ETDEWEB)

    Soten, I.; Miguez, H.; Yang, S.M.; Petrov, S.; Coombs, N.; Tetreault, N.; Ozin, G.A. [Toronto Univ., ON (Canada). Dept. of Chemistry; Matsuura, N.; Ruda, H.E. [Toronto Univ., ON (Canada). Dept. of Metallurgy and Materials Science

    2002-01-01

    The engineering of cubic or tetragonal polymorphs of nanocrystalline barium titanate inverted opals has been achieved by thermally induced transformations. Optical characterization demonstrated photonic crystal behavior of the opals. The tuning of the ferroelectric-paraelectric transition around the Curie temperature is shown in this paper. (orig.)

  18. Physicochemical characterization of fish protein adlayers with bacteria repelling properties.

    Science.gov (United States)

    Meyer, R L; Arpanaei, A; Pillai, S; Bernbom, N; Enghild, J J; Ng, Y Y; Gram, L; Besenbacher, F; Kingshott, P

    2013-02-01

    Materials coated with aqueous fish protein extracts can reduce bacterial adhesion, but the mechanism behind the observed effect is not fully understood. In this study we explore the physicochemical properties of fish muscle protein adlayers on four substrates: gold, stainless steel, polystyrene and silicon dioxide. The aims were (i) to determine if the anti-adhesive effect is independent of the underlying substrate chemistry, (ii) to link the physicochemical properties of the adlayer to its ability to repel bacteria, and (iii) to elucidate the mechanism behind this effect. The main proteins on all surfaces were the muscle proteins troponin, tropomyosin, and myosin, and the lipid binding protein apolipoprotein. The quantity, viscoelasticity, and hydration of the protein adlayers varied greatly on the different substrates, but this variation did not affect the bacterial repelling properties. Our results imply that these proteins adsorb to all substrates and provide a steric barrier towards bacterial adhesion, potentially providing a universal antifouling solution. PMID:23104021

  19. Physicochemical characterization of fish protein adlayers with bacteria repelling properties

    DEFF Research Database (Denmark)

    Meyer, R. L.; Arpanaei, A.; Pillai, S.;

    2013-01-01

    and silicon dioxide. The aims were (i) to determine if the anti-adhesive effect is independent of the underlying substrate chemistry, (ii) to link the physicochemical properties of the adlayer to its ability to repel bacteria, and (iii) to elucidate the mechanism behind this effect. The main proteins on all...... surfaces were the muscle proteins troponin, tropomyosin, and myosin, and the lipid binding protein apolipoprotein. The quantity, viscoelasticity, and hydration of the protein adlayers varied greatly on the different substrates, but this variation did not affect the bacterial repelling properties. Our...

  20. Material Property Characterization of AS4/VRM-34 Textile Laminates

    Science.gov (United States)

    Grenoble, Ray W.; Johnston, William M

    2013-01-01

    Several material properties (modulus, strengths, and fracture toughness) of a textile composite have been evaluated to provide input data to analytical models of Pultruded Rod Stiffened Efficient Unitized Structure (PRSEUS). The material system is based on warp-knitted preforms of AS4 carbon fibers and VRM-34 epoxy resin, which have been processed via resin infusion and oven curing. Tensile, compressive, shear, and fracture toughness properties have been measured at ambient and elevated temperatures. All specimens were tested in as-fabricated (dry) condition. Specimens were tested with and without through-thickness stitching.

  1. Characterization of Viscoelastic Properties of Polymeric Materials Through Nanoindentation

    Science.gov (United States)

    Odegard, G. M.; Bandorawalla, T.; Herring, H. M.; Gates, T. S.

    2003-01-01

    Nanoindentation is used to determine the dynamic viscoelastic properties of six polymer materials. It is shown that varying the harmonic frequency of the nanoindentation does not have any significant effect on the measured storage and loss moduli of the polymers. Agreement is found between these results and data from DMA testing of the same materials. Varying the harmonic amplitude of the nanoindentation does not have a significant effect on the measured properties of the high performance resins, however, the storage modulus of the polyethylene decreases as the harmonic amplitude increases. Measured storage and loss moduli are also shown to depend on the density of the polyethylene.

  2. Characterization of High Temperature Mechanical Properties Using Laser Ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    David Hurley; Stephen Reese; Farhad Farzbod; Rory Kennedy

    2012-05-01

    Mechanical properties are controlled to a large degree by defect structures such as dislocations and grain boundaries. These microstructural features involve a perturbation of the perfect crystal lattice (i.e. strain fields). Viewed in this context, high frequency strain waves (i.e. ultrasound) provide a natural choice to study microstructure mediated mechanical properties. In this presentation we use laser ultrasound to probe mechanical properties of materials. This approach utilizes lasers to excite and detect ultrasonic waves, and as a consequence has unique advantages over other methods—it is noncontacting, requires no couplant or invasive sample preparation (other than that used in metallurgical analysis), and has the demonstrated capability to probe microstructure on a micron scale. Laser techniques are highly reproducible enabling sophisticated, microstructurally informed data analysis. Since light is being used for generation and detection of the ultrasonic wave, the specimen being examined is not mechanically coupled to the transducer. As a result, laser ultrasound can be carried out remotely, an especially attractive characteristic for in situ measurements in severe environments. Several examples involving laser ultrasound to measure mechanical properties in high temperature environments will be presented. Emphasis will be place on understanding the role of grain microstructure.

  3. Synthesis, characterization and properties of polyaniline/expanded vermiculite intercalated nanocomposite

    OpenAIRE

    Jianming Lin, Qunwei Tang, Jihuai Wu and Hui Sun

    2008-01-01

    The synthesis characterization and conductivities of polyaniline/expanded vermiculite intercalated nanocomposite are presented in this paper. The conductive emeraldine salt form of polyaniline is inserted into the interlayer of expanded vermiculite to produce the nanocomposite with high conductivity. The structures and properties are characterized by transmission electron microscopy x-ray diffraction spectroscopy fourier transform infrared spectroscopy thermogravimetry analysis and by the mea...

  4. Biodegradable Polycaprolactone-Titania Nanocomposites: Preparation, Characterization and Antimicrobial Properties

    OpenAIRE

    Alexandra Muñoz-Bonilla; Cerrada, María L.; Marta Fernández-García; Anna Kubacka; Manuel Ferrer; Marcos Fernández-García

    2013-01-01

    Nanocomposites obtained from the incorporation of synthesized TiO2 nanoparticles (≈10 nm average primary particle size) in different amounts, ranging from 0.5 to 5 wt.%, into a biodegradable polycaprolactone matrix are achieved via a straightforward and commercial melting processing. The resulting nanocomposites have been structurally and thermally characterized by transmission electron microscopy (TEM), wide/small angle X-ray diffraction (WAXS/SAXS, respectively) and differential scanning ca...

  5. CHARACTERIZATION AND PROPERTIES OF A LIGNOSULFONATE-BASED PHENOLIC FOAM

    OpenAIRE

    Lihong Hu; Yonghong Zhou; Meng Zhang; Ruijie Liu

    2011-01-01

    Phenolated lignosulfonate was introduced into the synthesis of phenolic resol with phenol and formaldehyde in an alkaline condition. The modified resol was successfully applied to prepare phenolic foam using appropriate combinations of flowing agents. N-pentane was found to be suitable as the foaming agent. Sulphuric acid (50% aqueous solution, w/w) and Tween-80 were used as catalyst and surfactant, respectively. The obtained foams were characterized by thermogravimetric analysis (TGA), scann...

  6. Characterization-Based Molecular Design of Bio-Fuel Additives Using Chemometric and Property Clustering Techniques

    OpenAIRE

    Subin eHada; Charles Conrad Solvason; Mario Richard Eden

    2014-01-01

    In this work, multivariate characterization data such as infrared spectroscopy was used as a source of descriptor data involving information on molecular architecture for designing structured molecules with tailored properties. Application of multivariate statistical techniques such as principal component analysis allowed capturing important features of the molecular architecture from enormous amount of complex data to build appropriate latent variable models. Combining the property clusterin...

  7. Characterization of the finite variation property for a class of stationary increment infinitely divisible processes

    DEFF Research Database (Denmark)

    Basse-O'Connor, Andreas; Rosiński, Jan

    2013-01-01

    We characterize the finite variation property for stationary increment mixed moving averages driven by infinitely divisible random measures. Such processes include fractional and moving average processes driven by Levy processes, and also their mixtures. We establish two types of zero-one laws for...... the finite variation property. We also consider some examples to illustrate our results....

  8. Tensile-property characterization of thermally aged cast stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Michaud, W.F.; Toben, P.T.; Soppet, W.K.; Chopra, O.K. [Argonne National Lab., IL (United States)

    1994-02-01

    The effect of thermal aging on tensile properties of cast stainless steels during service in light water reactors has been evaluated. Tensile data for several experimental and commercial heats of cast stainless steels are presented. Thermal aging increases the tensile strength of these steels. The high-C Mo-bearing CF-8M steels are more susceptible to thermal aging than the Mo-free CF-3 or CF-8 steels. A procedure and correlations are presented for predicting the change in tensile flow and yield stresses and engineering stress-vs.-strain curve of cast stainless steel as a function of time and temperature of service. The tensile properties of aged cast stainless steel are estimated from known material information, i.e., chemical composition and the initial tensile strength of the steel. The correlations described in this report may be used for assessing thermal embrittlement of cast stainless steel components.

  9. Preparation, characterization and functional properties of flax seed protein isolate.

    Science.gov (United States)

    Kaushik, Pratibha; Dowling, Kim; McKnight, Stafford; Barrow, Colin J; Wang, Bo; Adhikari, Benu

    2016-04-15

    Flaxseed protein isolate (FPI) was extracted from flaxseeds, and its amino acid composition and functional properties (solubility, thermal stability, emulsifying properties and electrostatic charge density, water holding and fat absorption capacities) were determined. The highest purity of FPI (90.6%) was achieved by extraction at 60°C. FPI had a low lysine to arginine ratio of 0.25, which is desired in heart-healthy foods and infant formulas. The denaturation temperature of FPI was 105°C. FPI had the highest emulsion activity index (375.51 m(2)/g), highest emulsion stability index (179.5 h) and zeta potential (-67.4 mV) when compared to those of other commonly used proteins, such as sodium caseinate (SC), whey protein isolate (WPI), gelatin (Gel) and soy protein isolate (SPI). The average emulsion droplet size of emulsions stabilized by these proteins was in the order SCproteins. PMID:26616943

  10. Tensile-property characterization of thermally aged cast stainless steels

    International Nuclear Information System (INIS)

    The effect of thermal aging on tensile properties of cast stainless steels during service in light water reactors has been evaluated. Tensile data for several experimental and commercial heats of cast stainless steels are presented. Thermal aging increases the tensile strength of these steels. The high-C Mo-bearing CF-8M steels are more susceptible to thermal aging than the Mo-free CF-3 or CF-8 steels. A procedure and correlations are presented for predicting the change in tensile flow and yield stresses and engineering stress-vs.-strain curve of cast stainless steel as a function of time and temperature of service. The tensile properties of aged cast stainless steel are estimated from known material information, i.e., chemical composition and the initial tensile strength of the steel. The correlations described in this report may be used for assessing thermal embrittlement of cast stainless steel components

  11. Characterization of the adherence properties of Streptococcus salivarius.

    OpenAIRE

    Weerkamp, A H; McBride, B C

    1980-01-01

    The adherence and aggregation properties of 46 human oral Streptococcus salivarius isolates were examined. A total of 41% of the isolates aggregated with whole human saliva, 50% aggregated with human erythrocytes, and 85% adhered to human buccal epithelial cells. Strains that aggregated with saliva and erythrocytes usually reacted with Streptococcus group K typing serum whereas the non-hemagglutinating strains did not. K+ strains also adhered more strongly to human buccal epithelial cells tha...

  12. Characterization of Mechanical Properties of Porcelain Tile Using Ultrasonics

    OpenAIRE

    KURAMA, Semra; Eren, Elif

    2012-01-01

    Ultrasound affords a very useful and versatile non-destructive method, using a large application area, for evaluating the microstructure and mechanical properties of materials. In this study, porcelain tiles were sintered at different temperatures to change their porosity. Following this, the time of flight of both longitudinal and shear waves was measured through the tile. The time of flight of ultrasonic waves was measured using a contact ultrasonic transducer operating on a pulse-echo mode...

  13. Synthesis, characterization, and properties of reduced europium molybdates and tungstates

    International Nuclear Information System (INIS)

    Single crystals of K0.094Eu0.906MoO4, K0.097Eu0.903WO4, EuWO4, and EuMoO4 were grown from molten chloride fluxes contained in vacuum-sealed fused silica and structurally characterized via single crystal X-ray diffraction. The in situ reduction of Eu3+ to Eu2+ was carried out using Mo, W, and Zn as metal reducing agents. All four compounds crystallize in the tetragonal space group of I41/a and adopt the scheelite (CaWO4) structure type. The magnetic susceptibility of the reported compounds shows paramagnetic behavior down to 2 K. 151Eu Mössbauer spectroscopy was used to analyze the relative Eu2+ and Eu3+ content of the samples. All the compounds were further characterized by EPR, and UV-vis spectroscopy. - Graphical abstract: TOC Caption Two new reduced europium containing quaternary oxides, K0.094Eu0.906MoO4 and K0.097Eu0.903WO4, and two previously reported ternary reduced oxides, EuWO4 and EuMoO4, were synthesized via an in situ reduction of Eu3+ to Eu2+ under flux method using Mo, W, and Zn as metal reducing agents. 151Eu Mössbauer spectroscopy was used to analyze the relative Eu2+ and Eu3+ content of the samples. - Highlights: • K0.094Eu0.906MoO4, K0.097Eu0.903WO4, EuWO4, and EuMoO4 have been synthesized and characterized. • The in situ reduction of Eu3+ to Eu2+ was carried out using Mo, W, and Zn as metal reducing agents. • Magnetic susceptibility data were collected. • 151Eu Mössbauer spectroscopy was used to analyze Eu2+ and Eu3+ content

  14. Synthesis and characterization of lamellar aragonite with hydrophobic property

    International Nuclear Information System (INIS)

    A novel and simple synthetic method for the preparation of hydrophobic lamellar aragonite has been developed. The crystallization of aragonite was conducted by the reaction of sodium carbonate with calcium chloride in the presence of sodium stearate. The resulting products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and the contact angle. The results revealed that sodium stearate plays an important role in determining the structure and morphology of the sample. Besides, we have succeeded in surface modification of particles in situ at the same time. The contact angle of the modified aragonite reached 108.59 deg.

  15. PtCo/Au nanocomposite: Synthesis, characterization, and magnetic properties

    Science.gov (United States)

    Dai, Jingtao; Du, Yukou; Wang, Fangwei; Yang, Ping

    2007-09-01

    Magnetic PtCo/Au nanocomposites with narrow size distribution were synthesized in a reverse micelle, followed by a post-synthesis handling of the stabilizer-exchange technique. The PtCo/Au nanocomposites were characterized by ultraviolet visible spectroscopy, X-ray diffraction and transmission electron microscopy, respectively. Superconducting quantum interference device studies revealed that the nanocomposites were superparamagnetic above the blocking temperature ( TB=69 K), while the samples were ferromagnetic with Hc (628 Oe) and Ms (2.97 emu /g) at 5 K.

  16. Characterization and properties of sepiolite/polyurethane nanocomposites

    International Nuclear Information System (INIS)

    In situ polymerization method is employed to prepare sepiolite/polyurethane nanocomposite. The morphology and the dispersion of sepiolite in polyurethane have been characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope and Fourier transform infrared spectroscopy. The results show the sepiolite is dispersed homogeneously in the polyurethane matrix at a nanometer scale. The tensile test shows that the tensile strength and elongation at break for the nanocomposites increase with the addition of sepiolite as compared to those of the pure polyurethane. The TGA analysis reveals that the addition of nanofillers results in the higher thermal stability

  17. Anomalies in quantum field theory: Properties and characterization

    OpenAIRE

    Kraus, Elisabeth

    2002-01-01

    We consider the Adler-Bardeen anomaly of the U(1) axial current in abelian and non-abelian gauge theories and present its algebraic characterization as well as an explicit evaluation proving regularization scheme independence of the anomaly. By extending the gauge coupling to an external space-time dependent field we get a unique definition for the quantum corrections of the topological term. It also implies a simple proof of the non-renormalization theorem of the Adler-Bardeen anomaly. We co...

  18. Characterization of optical polarization properties for liquid crystal-based retarders.

    Science.gov (United States)

    López-Téllez, Juan M; Bruce, Neil C; Rodríguez-Herrera, Oscar G

    2016-08-01

    We present the analysis and implementation of a set of experimental procedures to characterize optical polarization properties as a function of the applied voltage for liquid-crystal variable retarders (LCVRs) in the transmission mode. The studied properties are those involved in the operation of the LCVRs and, generally, are the most significant for optical applications: retardance, diattenuation, optical axes position, and output depolarization effects. The correct characterization of these polarization properties can be useful to improve results or estimate errors in applications using these devices. The results obtained show good accuracy and good agreement with the expected results. PMID:27505384

  19. Characterization and luminescent properties of thermally annealed olivines

    International Nuclear Information System (INIS)

    Olivine is an iron-magnesium solid solution silicate (Mg,Fe)2SiO4 and it is probably one of the most abundant mineral phase in the Solar System, it is present in the primitive carbonaceous meteorites (i.e Allende), and in ordinary chondritic meteorite, comets or terrestrial planets. The olivine grains in those bodies have been exposed to different radiation sources like UV, electrons, cosmic radiation, etc. Here, we explore the effect of ionizing and non ionizing radiation on the luminescence emission of the two well-characterised olivine samples from Mexico and Spain by means of cathodoluminescence and thermoluminescence. The analyses by X-ray dispersive energies in the scanning electron microscopy show differences between the samples in the amount of iron and magnesium and also show traces of rare elements. Olivine exhibits spectral cathodoluminescence emissions of low intensity, explained for the quenching of the luminescence of the iron, and sharp signals assigned as impurities. Cathodoluminescence and thermoluminescence glow curves of the natural, and UV induced olivine samples were obtained. Our results show that thermal treatments at 1100 °C change the mineral molecular structure and the luminescence properties of this mineral phase. These results confirm an active participation of physical factors influencing the luminescent properties of olivine. -- Highlights: ► Luminescent properties of two olivines samples (Mexican and Spanish) were explored. ► EDS show different iron and magnesium content and traces of rare elements on both. ► Olivine exhibits spectral CL emissions of low intensity due to the quenching of iron. ► Treatments at 1100 °C change the mineral structure and its response to UV radiation

  20. Characterization of Photon Statistical Properties with Normalized Mandel Parameter

    International Nuclear Information System (INIS)

    Normalized Mandel Parameter (Q) is introduced as a new measurement of photon statistics. Dependences of Mandel parameter Q and corresponding normalized Mandel parameter (Q) on photon-counting time interval are experimentally investigated for pseudo-thermal light. We demonstrate that (Q) is more appropriate than Q to measure the statistical deviation from Poisson distribution, because (Q) presents clearly both the intrinsic statistical properties and measuring effects. The advantages of (Q) in charactering nonclassical emissions are also discussed. (fundamental areas of phenomenology(including applications))

  1. Characterization, Microstructure, and Dielectric properties of cubic pyrochlore structural ceramics

    KAUST Repository

    Li, Yangyang

    2013-05-01

    The (BMN) bulk materials were sintered at 1050°C, 1100°C, 1150°C, 1200°C by the conventional ceramic process, and their microstructure and dielectric properties were investigated by Scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, Transmission electron microscopy (TEM) (including the X-ray energy dispersive spectrometry EDS and high resolution transmission electron microscopy HRTEM) and dielectric impedance analyzer. We systematically investigated the structure, dielectric properties and voltage tunable property of the ceramics prepared at different sintering temperatures. The XRD patterns demonstrated that the synthesized BMN solid solutions had cubic phase pyrochlore-type structure when sintered at 1050°C or higher, and the lattice parameter (a) of the unit cell in BMN solid solution was calculated to be about 10.56Å. The vibrational peaks observed in the Raman spectra of BMN solid solutions also confirmed the cubic phase pyrochlore-type structure of the synthesized BMN. According to the Scanning Electron Microscope (SEM) images, the grain size increased with increasing sintering temperature. Additionally, it was shown that the densities of the BMN ceramic tablets vary with sintering temperature. The calculated theoretical density for the BMN ceramic tablets sintered at different temperatures is about 6.7521 . The density of the respective measured tablets is usually amounting more than 91% and 5 approaching a maximum value of 96.5% for sintering temperature of 1150°C. The microstructure was investigated by using Scanning Transmission Electron Microscope (STEM), X-ray diffraction (XRD). Combined with the results obtained from the STEM and XRD, the impact of sintering temperature on the macroscopic and microscopic structure was discussed. The relative dielectric constant ( ) and dielectric loss ( ) of the BMN solid solutions were measured to be 161-200 and (at room temperature and 100Hz-1MHz), respectively. The BMN solid

  2. Synthesis, characterization, and properties of reduced europium molybdates and tungstates

    Energy Technology Data Exchange (ETDEWEB)

    Abeysinghe, Dileka [Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208 (United States); Gerke, Birgit [Institut für Anorganische und Analytische Chemie, Universität Münster , Corrensstrasse 30, Münster D-48149 (Germany); Morrison, Gregory; Hsieh, Chun H.; Smith, Mark D. [Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208 (United States); Pöttgen, Rainer [Institut für Anorganische und Analytische Chemie, Universität Münster , Corrensstrasse 30, Münster D-48149 (Germany); Makris, Thomas M. [Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208 (United States); Loye, Hans-Conrad zur, E-mail: zurloye@mailbox.sc.edu [Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208 (United States)

    2015-09-15

    Single crystals of K{sub 0.094}Eu{sub 0.906}MoO{sub 4}, K{sub 0.097}Eu{sub 0.903}WO{sub 4}, EuWO{sub 4}, and EuMoO{sub 4} were grown from molten chloride fluxes contained in vacuum-sealed fused silica and structurally characterized via single crystal X-ray diffraction. The in situ reduction of Eu{sup 3+} to Eu{sup 2+} was carried out using Mo, W, and Zn as metal reducing agents. All four compounds crystallize in the tetragonal space group of I4{sub 1}/a and adopt the scheelite (CaWO{sub 4}) structure type. The magnetic susceptibility of the reported compounds shows paramagnetic behavior down to 2 K. {sup 151}Eu Mössbauer spectroscopy was used to analyze the relative Eu{sup 2+} and Eu{sup 3+} content of the samples. All the compounds were further characterized by EPR, and UV-vis spectroscopy. - Graphical abstract: TOC Caption Two new reduced europium containing quaternary oxides, K{sub 0.094}Eu{sub 0.906}MoO{sub 4} and K{sub 0.097}Eu{sub 0.903}WO{sub 4}, and two previously reported ternary reduced oxides, EuWO{sub 4} and EuMoO{sub 4}, were synthesized via an in situ reduction of Eu{sup 3+} to Eu{sup 2+} under flux method using Mo, W, and Zn as metal reducing agents. {sup 151}Eu Mössbauer spectroscopy was used to analyze the relative Eu{sup 2+} and Eu{sup 3+} content of the samples. - Highlights: • K{sub 0.094}Eu{sub 0.906}MoO{sub 4}, K{sub 0.097}Eu{sub 0.903}WO{sub 4}, EuWO{sub 4}, and EuMoO{sub 4} have been synthesized and characterized. • The in situ reduction of Eu{sup 3+} to Eu{sup 2+} was carried out using Mo, W, and Zn as metal reducing agents. • Magnetic susceptibility data were collected. • {sup 151}Eu Mössbauer spectroscopy was used to analyze Eu{sup 2+} and Eu{sup 3+} content.

  3. Synthesis, characterization, and antimicrobial properties of copper nanoparticles

    Science.gov (United States)

    Usman, Muhammad Sani; Zowalaty, Mohamed Ezzat El; Shameli, Kamyar; Zainuddin, Norhazlin; Salama, Mohamed; Ibrahim, Nor Azowa

    2013-01-01

    Copper nanoparticle synthesis has been gaining attention due to its availability. However, factors such as agglomeration and rapid oxidation have made it a difficult research area. In the present work, pure copper nanoparticles were prepared in the presence of a chitosan stabilizer through chemical means. The purity of the nanoparticles was authenticated using different characterization techniques, including ultraviolet visible spectroscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and field emission scanning electron microscopy. The antibacterial as well as antifungal activity of the nanoparticles were investigated using several microorganisms of interest, including methicillin-resistant Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Salmonella choleraesuis, and Candida albicans. The effect of a chitosan medium on growth of the microorganism was studied, and this was found to influence growth rate. The size of the copper nanoparticles obtained was in the range of 2–350 nm, depending on the concentration of the chitosan stabilizer. PMID:24293998

  4. Synthesis, characterization and electrostatic properties of WS2 nanostructures

    Directory of Open Access Journals (Sweden)

    Yinping Fan

    2014-05-01

    Full Text Available We report the direct growth of atomically thin WS2 nanoplates and nanofilms on the SiO2/Si (300 nm substrate by vapor phase deposition method without any catalyst. The WS2 nanostructures were systematically characterized by optical microscopy, scanning electron microscopy, Raman microscopy and atomic force microscopy. We found that growth time and growth temperature play important roles in the morphology of WS2 nanostructures. Moreover, by using Kelvin probe force microscopy, we found that the WS2 nanoplates exhibit uniform surface and charge distributions less than 10 mV fluctuations. Our results may apply to the study of other transition metal dichalcogenides by vapor phase deposition method.

  5. Thermal property of biological tissues characterized by piezoelectric photoacoustic technique

    Institute of Scientific and Technical Information of China (English)

    GAO Chunming; ZHANG Shuyi; CHEN Yan; SHUI Xiuji; YANG Yuetao

    2004-01-01

    A photoacoustic piezoelectric method based on a simplified thermoelastic theory is employed to determine thermal diffusivities of biological tissues. The thermal diffusivities of porcine tissues with different preparation conditions, including fresh, dry and specially prepared conditions, are characterized. Comparing the experimental evaluated diffusivities of the tissues in three conditions with each other, it can be seen that the diffusivities of the fresh tissues are the biggest and the diffusivities of the specially prepared tissues are bigger than that of the dry ones generally. The results show that the piezoelectric photoacoustic method is especially effective for determining macro-effective (average) thermal diffusivities of biological materials with micro- inhomogeneity and easy to be performed, which can provide useful information for researching thermal characters of biological tissues.

  6. Synthesis, characterization and properties of hollow nickel phosphide nanospheres

    Energy Technology Data Exchange (ETDEWEB)

    Ni Yonghong; Tao Ali; Hu Guangzhi; Cao Xiaofeng; Wei Xianwen; Yang Zhousheng [College of Chemistry and Materials Science, Anhui Key Laboratory of Functional Molecular Solids, Anhui Normal University, Wuhu 241000 (China)

    2006-10-14

    Nickel phosphide (Ni{sub 12}P{sub 5}) hollow nanospheres with a mean diameter of 100 nm and a shell thickness of 15-20 nm have been successfully prepared by a hydrothermal-microemulsion route, using NaH{sub 2}PO{sub 2} as a phosphorus source. XRD, EDS (HR)TEM, SEM and the SAED pattern were used to characterize the final product. Experiments showed that the as-prepared nickel phosphide hollow nanospheres could selectively catalytically degrade some organic dyes such as methyl red and Safranine T under 254 nm UV light irradiation. At the same time, the nickel phosphide hollow nanospheres showed a stronger ability to promote electron transfer between the glass-carbon electrode and adrenalin than nickel phosphide honeycomb-like particles prepared by a simple hydrothermal route. A possible formation process for nickel phosphide hollow nanospheres was suggested based on the experimental results.

  7. Physical characterization of functionalized spider silk: electronic and sensing properties

    Energy Technology Data Exchange (ETDEWEB)

    Steven, Eden; Brooks, James S [Department of Physics and National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac, Tallahassee, FL 32310 (United States); Park, Jin Gyu [FAMU-FSU Department of Industrial and Manufacturing Engineering, High-Performance Materials Institute, Florida State University, 2005 Levy Ave., Tallahassee, FL 32310 (United States); Paravastu, Anant; Siegrist, Theo; Kaner, Papatya; Alamo, Rufina G [FAMU-FSU Department of Chemical and Biomedical Engineering and National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac, Tallahassee, FL 32310 (United States); Branco Lopes, Elsa [Departamento de Quimica, Instituto Tecnologico e Nuclear/CFMC-UL, P-2686-953 Sacavem (Portugal); Englander, Ongi, E-mail: esteven@magnet.fsu.edu [FAMU-FSU Department of Mechanical Engineering and National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac, Tallahassee, Florida 32310 (United States)

    2011-10-15

    This work explores functional, fundamental and applied aspects of naturally harvested spider silk fibers. Natural silk is a protein polymer where different amino acids control the physical properties of fibroin bundles, producing, for example, combinations of {beta}-sheet (crystalline) and amorphous (helical) structural regions. This complexity presents opportunities for functional modification to obtain new types of material properties. Electrical conductivity is the starting point of this investigation, where the insulating nature of neat silk under ambient conditions is described first. Modification of the conductivity by humidity, exposure to polar solvents, iodine doping, pyrolization and deposition of a thin metallic film are explored next. The conductivity increases exponentially with relative humidity and/or solvent, whereas only an incremental increase occurs after iodine doping. In contrast, iodine doping, optimal at 70 deg. C, has a strong effect on the morphology of silk bundles (increasing their size), on the process of pyrolization (suppressing mass loss rates) and on the resulting carbonized fiber structure (that becomes more robust against bending and strain). The effects of iodine doping and other functional parameters (vacuum and thin film coating) motivated an investigation with magic angle spinning nuclear magnetic resonance (MAS-NMR) to monitor doping-induced changes in the amino acid-protein backbone signature. MAS-NMR revealed a moderate effect of iodine on the helical and {beta}-sheet structures, and a lesser effect of gold sputtering. The effects of iodine doping were further probed by Fourier transform infrared (FTIR) spectroscopy, revealing a partial transformation of {beta}-sheet-to-amorphous constituency. A model is proposed, based on the findings from the MAS-NMR and FTIR, which involves iodine-induced changes in the silk fibroin bundle environment that can account for the altered physical properties. Finally, proof

  8. Physical characterization of functionalized spider silk: electronic and sensing properties

    International Nuclear Information System (INIS)

    This work explores functional, fundamental and applied aspects of naturally harvested spider silk fibers. Natural silk is a protein polymer where different amino acids control the physical properties of fibroin bundles, producing, for example, combinations of β-sheet (crystalline) and amorphous (helical) structural regions. This complexity presents opportunities for functional modification to obtain new types of material properties. Electrical conductivity is the starting point of this investigation, where the insulating nature of neat silk under ambient conditions is described first. Modification of the conductivity by humidity, exposure to polar solvents, iodine doping, pyrolization and deposition of a thin metallic film are explored next. The conductivity increases exponentially with relative humidity and/or solvent, whereas only an incremental increase occurs after iodine doping. In contrast, iodine doping, optimal at 70 deg. C, has a strong effect on the morphology of silk bundles (increasing their size), on the process of pyrolization (suppressing mass loss rates) and on the resulting carbonized fiber structure (that becomes more robust against bending and strain). The effects of iodine doping and other functional parameters (vacuum and thin film coating) motivated an investigation with magic angle spinning nuclear magnetic resonance (MAS-NMR) to monitor doping-induced changes in the amino acid-protein backbone signature. MAS-NMR revealed a moderate effect of iodine on the helical and β-sheet structures, and a lesser effect of gold sputtering. The effects of iodine doping were further probed by Fourier transform infrared (FTIR) spectroscopy, revealing a partial transformation of β-sheet-to-amorphous constituency. A model is proposed, based on the findings from the MAS-NMR and FTIR, which involves iodine-induced changes in the silk fibroin bundle environment that can account for the altered physical properties. Finally, proof-of-concept applications of

  9. Characterization of the adherence properties of Streptococcus salivarius.

    Science.gov (United States)

    Weerkamp, A H; McBride, B C

    1980-01-01

    The adherence and aggregation properties of 46 human oral Streptococcus salivarius isolates were examined. A total of 41% of the isolates aggregated with whole human saliva, 50% aggregated with human erythrocytes, and 85% adhered to human buccal epithelial cells. Strains that aggregated with saliva and erythrocytes usually reacted with Streptococcus group K typing serum whereas the non-hemagglutinating strains did not. K+ strains also adhered more strongly to human buccal epithelial cells than K- strains. All isolates coaggregated with Fusobacterium nucleatum LF and Bacteroides asaccharolyticus 2D, 91% coaggregated with Veillonella alcalescens V1, and 50% coaggregated with Veillonella parvula V4. S. salivarius HB aggregated with saliva from 15 different human donors and aggregated with human erythrocytes irrespective of the blood group. This strain only weakly aggregated with rat saliva or rat erythrocytes. We isolated mutants which concomitantly lost the ability to agglutinate erythrocytes, aggregate with saliva, and bind to buccal epithelial cells, but retained their interbacterial aggregation properties. A second class of mutants lost the ability to coaggregate with Veillonella, but these mutants retained all of the other aggregation properties. Treatment of S. salivarius HB cells with pronase or subtilisin destroyed their ability to aggregate with saliva and erythrocytes and to bind to buccal epithelial cells. The unique characteristics of the aggregation and adherence reactions were suggested by differences in the rate of loss of activity during protease treatment and in the response to chemical modification. The presence of saliva did not affect hemagglutination and adherence to buccal epithelial cells. Binding of the salivary aggregating factor to the bacteria could be distinguished from aggregation on the basis that the latter required divalent cations. The factor involved in coaggregation with F. nucleatum LF was physicochemically different from the other

  10. Physical characterization of functionalized spider silk: electronic and sensing properties

    Directory of Open Access Journals (Sweden)

    Eden Steven, Jin Gyu Park, Anant Paravastu, Elsa Branco Lopes, James S Brooks, Ongi Englander, Theo Siegrist, Papatya Kaner and Rufina G Alamo

    2011-01-01

    Full Text Available This work explores functional, fundamental and applied aspects of naturally harvested spider silk fibers. Natural silk is a protein polymer where different amino acids control the physical properties of fibroin bundles, producing, for example, combinations of β-sheet (crystalline and amorphous (helical structural regions. This complexity presents opportunities for functional modification to obtain new types of material properties. Electrical conductivity is the starting point of this investigation, where the insulating nature of neat silk under ambient conditions is described first. Modification of the conductivity by humidity, exposure to polar solvents, iodine doping, pyrolization and deposition of a thin metallic film are explored next. The conductivity increases exponentially with relative humidity and/or solvent, whereas only an incremental increase occurs after iodine doping. In contrast, iodine doping, optimal at 70 °C, has a strong effect on the morphology of silk bundles (increasing their size, on the process of pyrolization (suppressing mass loss rates and on the resulting carbonized fiber structure (that becomes more robust against bending and strain. The effects of iodine doping and other functional parameters (vacuum and thin film coating motivated an investigation with magic angle spinning nuclear magnetic resonance (MAS-NMR to monitor doping-induced changes in the amino acid-protein backbone signature. MAS-NMR revealed a moderate effect of iodine on the helical and β-sheet structures, and a lesser effect of gold sputtering. The effects of iodine doping were further probed by Fourier transform infrared (FTIR spectroscopy, revealing a partial transformation of β-sheet-to-amorphous constituency. A model is proposed, based on the findings from the MAS-NMR and FTIR, which involves iodine-induced changes in the silk fibroin bundle environment that can account for the altered physical properties. Finally, proof

  11. Preparation, Characterization and Properties of Graphene-silver Sulphide Hybrid

    Institute of Scientific and Technical Information of China (English)

    CHEN Guang-yi; WEI Zhi-yong; LIANG Ce; WANG De-jin; LIANG Ji-cai; ZHANG Wan-xi

    2012-01-01

    A facile and efficient strategy was reported for the preparation of graphene nanosheets-Ag2S hybrid by a simple hydrothermal process.First,Ag2S particles deposited on the surface of graphene oxide(GO) sheet.GO was then reduced by hydrazine hydrate to graphcne.The results of X-ray diffraction(XRD) and Fourier transform infrared(FTIR) demonstrated the efficient reduction of GO to graphene.Transmission electron microscopy(TEM) image of the sample reveals the morphology of the architecture of graphene-Ag2S hybrid.Ultraviolet-visible spectroscopy(UV-Vis) and photoluminescence(PL) measurement were further employed to study the optical properties of the obtained nanocomposite.This work can be extended to design other graphene-based hybrid nanomaterials,and the as-grown architectures may hold promise for many applications.

  12. Chrysanthemum-like bismuth sulfide microcrystals: Synthesis, characterization, and properties

    Science.gov (United States)

    Jiang, Jinghui; Gao, Guanhua; Yu, Runnan; Qiu, Guanzhou; Liu, Xiaohe

    2011-02-01

    Uniform chrysanthemum-like bismuth sulfide (Bi 2S 3) microcrystals assembled from nanosheet building blocks were successfully synthesized via a convenient hydrothermal synthetic route under mild conditions in which hydrated bismuth nitrate and L-cysteine were employed to supply Bi and S source and ethylenediaminetetraacetic acid disodium salt (EDTA-Na 2) was employed as chelating agent. The influences of reaction temperatures and time on the morphologies of final products were investigated. The phase structures, morphologies, and properties of as-prepared products were investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscope, and photoluminescence spectra. The possible growth mechanism for the formation of chrysanthemum-like Bi 2S 3 microcrystals was discussed on the basis of the experimental results.

  13. Characterization of electrical and optical properties of silicon based materials

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Guobin

    2009-12-04

    In this work, the electrical and luminescence properties of a series of silicon based materials used for photovoltaics, microelectronics and nanoelectronics have been investigated by means of electron beam induced current (EBIC), cathodoluminescence (CL), photoluminescence (PL) and electroluminescence (EL) methods. Photovoltaic materials produced by block casting have been investigated by EBIC on wafers sliced from different parts of the ingot. Various solar cell processings have been compared in parallel wafers by means of EBIC collection efficiency measurements and contrast-temperature C(T) behaviors of the extended defects, i. e. dislocations and grain boundaries (GBs). It was found that the solar cell processing with phosphorus diffusion gettering (PDG) followed with a SiN firing greatly reduces the recombination activity of extended defects at room temperature, and improves the bulk property simultaneously. A remaining activity of the dislocations indicates the limitation of the PDG at extended defects. Abnormal behavior of the dislocation activity after certain solar cell processes was also observed in the region with high dislocation density, the dislocations are activated after certain solar cell processings. In order to evaluate the properties of a thin polycrystalline silicon layer prepared by Al-induced layer exchange (Alile) technique, epitaxially layer grown on silicon substrate with different orientations was used as a model system to investigate the impact by the process temperature and the substrates. EBIC energy dependent collection efficiency measurements reveal an improvement of the epilayer quality with increasing substrate temperature during the growth from 450 C to 650 C, and a decrease of epilayer quality at 700 C. PL measurements on the epitaxially grown Si layer on silicon substrates revealed no characteristic dislocation-related luminescence (DRL) lines at room temperature and 77 K, while in the samples prepared by Alile process, intense

  14. Characterization of physicochemical properties of ivy nanoparticles for cosmetic application

    Directory of Open Access Journals (Sweden)

    Huang Yujian

    2013-02-01

    Full Text Available Abstract Background Naturally occurring nanoparticles isolated from English ivy (Hedera helix have previously been proposed as an alternative to metallic nanoparticles as sunscreen fillers due to their effective UV extinction property, low toxicity and potential biodegradability. Methods This study focused on analyzing the physicochemical properties of the ivy nanoparticles, specifically, those parameters which are crucial for use as sunscreen fillers, such as pH, temperature, and UV irradiation. The visual transparency and cytotoxicity of ivy nanoparticles were also investigated comparing them with other metal oxide nanoparticles. Results Results from this study demonstrated that, after treatment at 100°C, there was a clear increase in the UV extinction spectra of the ivy nanoparticles caused by the partial decomposition. In addition, the UVA extinction spectra of the ivy nanoparticles gradually reduced slightly with the decrease of pH values in solvents. Prolonged UV irradiation indicated that the influence of UV light on the stability of the ivy nanoparticle was limited and time-independent. Compared to TiO2 and ZnO nanoparticles, ivy nanoparticles showed better visual transparency. Methylthiazol tetrazolium assay demonstrated that ivy nanoparticles exhibited lower cytotoxicity than the other two types of nanoparticles. Results also suggested that protein played an important role in modulating the three-dimensional structure of the ivy nanoparticles. Conclusions Based on the results from this study it can be concluded that the ivy nanoparticles are able to maintain their UV protective capability at wide range of temperature and pH values, further demonstrating their potential as an alternative to replace currently available metal oxide nanoparticles in sunscreen applications.

  15. Quantitative microstructure characterization and elastic properties upscaling of carbonate rocks

    Science.gov (United States)

    Vialle, Stephanie; Lebedev, Maxim

    2016-04-01

    Most Rock Physics models commonly used to predict elastic properties rely on a very simplified representation of the pore and grains geometry. Initially developed for siliclastic rocks, they do not apply easily and/or with as much success, to rocks with more complicated microstructure such as carbonates, which exhibit complex relationships between geophysical attributes and rock properties, such as P-wave velocity versus porosity. Furthermore, until recently, most microstructure imaging techniques such as optical microscopy, SEM, X-ray micro-CT, etc., only give a qualitative description of the pore and grain arrangement. Nano-indentation technique is a method that gives quantitative information by mean of local (micrometer size) measurements of elastic moduli. We used this technique to obtain 300 μm * 300 μm maps of Young's moduli (around 1000 data points) of two microporous carbonates of same mineralogy but of two different microstructures. As the size of the indenter tip is much smaller than the characteristic length of the heterogeneities in microstructure, the distribution of the Young's moduli can be deconvolved into its component parts (i.e. phases). SEM imaging of the same areas than the ones mapped by nano-indentation shows correlations between type of micrite and phases of different mean Young's modulus: tight micrites exhibiting a higher Young's modulus (up to 64 GPa) than microporous micrites (as low as 9 GPa). We then investigate different ways to upscale the measurements in order to get the effective bulk and shear moduli, from simply using volume fractions of the different phases, classical Hashin-Shrikman bounds, and Hill average; to using micro-CT imaging and analysis combined with rock physics models. Though more work is still needed to render nano-indentation technique a robust method for rock physics, both on the theory behind and on the upscaling of the measurements, these results that use nano-indentation method in a statistical way are very

  16. Rock mass mechanical property estimations for the Yucca Mountain Site Characterization Project

    International Nuclear Information System (INIS)

    Rock mass mechanical properties are important in the design of drifts and ramps. These properties are used in evaluations of the impacts of thermomechanical loading of potential host rock within the Yucca Mountain Site Characterization Project. Representative intact rock and joint mechanical properties were selected for welded and nonwelded tuffs from the currently available data sources. Rock mass qualities were then estimated using both the Norwegian Geotechnical Institute (Q) and Geomechanics Rating (RMR) systems. Rock mass mechanical properties were developed based on estimates of rock mass quality, the current knowledge of intact properties, and fracture/joint characteristics. Empirical relationships developed to correlate the rock mass quality indices and the rock mass mechanical properties were then used to estimate the range of rock mass mechanical properties

  17. New polymer target-shell properties and characterizations

    International Nuclear Information System (INIS)

    A method for characterizing ICF target shells is presented, based on measurement of the gas released from a single shell into a small volume. It utilizes cryogenic permeation systems developed in connection with our work on ICF targets containing nuclear spin-polarized deuterium. Permeation rates for polystyrene and parylene-coated-polystyrene shells are measured at temperatures from 350K down to 180K. Burst or implosion pressure can be determined over a full temperature range down to 20K. Shell temperature is calculated from its gas leakage rate, calibrated by permeation measurements over the temperature range. Lag of shell temperature compared with sample-chamber temperature during warming of the latter is attributed to the weakness of the thermal link provided by both radiative heat transfer and free molecular conduction with small accommodation coefficients for helium and deuterium gas at the structure to which the shell is conductively linked, or at the surface of a conductively isolated shell. Quantification of this lag can provide a measure of atomic scale roughness of the shell outer surface. Also presented are reversible pre-rupture leakage phenomena for polystyrene and parylene-coated-polystyrene shells

  18. Synthesis, characterization, and antimicrobial properties of copper nanoparticles

    Directory of Open Access Journals (Sweden)

    Usman MS

    2013-11-01

    Full Text Available Muhammad Sani Usman,1 Mohamed Ezzat El Zowalaty,2,5 Kamyar Shameli,1,3 Norhazlin Zainuddin,1 Mohamed Salama,4 Nor Azowa Ibrahim1 1Department of Chemistry, Faculty of Science, 2Laboratory of Vaccines and Immunotherapeutics, Institute of Bioscience, Universiti Putra Malaysia, Selangor, Malaysia; 3Materials and Energy, Research Center, Karaj, Iran; 4Faculty of Pharmacy, UiTM, Puncak Alam, Selangor, Malaysia; 5Department of Environmental Health, Faculty of Public Health and Tropical Medicine, Jazan University, Jazan, Kingdom of Saudi Arabia Abstract: Copper nanoparticle synthesis has been gaining attention due to its availability. However, factors such as agglomeration and rapid oxidation have made it a difficult research area. In the present work, pure copper nanoparticles were prepared in the presence of a chitosan stabilizer through chemical means. The purity of the nanoparticles was authenticated using different characterization techniques, including ultraviolet visible spectroscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and field emission scanning electron microscopy. The antibacterial as well as antifungal activity of the nanoparticles were investigated using several microorganisms of interest, including methicillin-resistant Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Salmonella choleraesuis, and Candida albicans. The effect of a chitosan medium on growth of the microorganism was studied, and this was found to influence growth rate. The size of the copper nanoparticles obtained was in the range of 2–350 nm, depending on the concentration of the chitosan stabilizer. Keywords: chitosan, copper nanoparticles, antimicrobial activity, chemical synthesis, aqueous medium

  19. Advanced optical measurements for characterizing photophysical properties of single nanoparticles.

    Energy Technology Data Exchange (ETDEWEB)

    Polsky, Ronen; Davis, Ryan W.; Arango, Dulce C.; Brozik, Susan Marie; Wheeler, David Roger

    2009-09-01

    Formation of complex nanomaterials would ideally involve single-pot reaction conditions with one reactive site per nanoparticle, resulting in a high yield of incrementally modified or oriented structures. Many studies in nanoparticle functionalization have sought to generate highly uniform nanoparticles with tailorable surface chemistry necessary to produce such conjugates, with limited success. In order to overcome these limitations, we have modified commercially available nanoparticles with multiple potential reaction sites for conjugation with single ssDNAs, proteins, and small unilamellar vesicles. These approaches combined heterobifunctional and biochemical template chemistries with single molecule optical methods for improved control of nanomaterial functionalization. Several interesting analytical results have been achieved by leveraging techniques unique to SNL, and provide multiple paths for future improvements for multiplex nanoparticle synthesis and characterization. Hyperspectral imaging has proven especially useful for assaying substrate immobilized fluorescent particles. In dynamic environments, temporal correlation spectroscopies have been employed for tracking changes in diffusion/hydrodynamic radii, particle size distributions, and identifying mobile versus immobile sample fractions at unbounded dilution. Finally, Raman fingerprinting of biological conjugates has been enabled by resonant signal enhancement provided by intimate interactions with nanoparticles and composite nanoshells.

  20. Microwave Synthesis, Characterization, and Photoluminescence Properties of Nanocrystalline Zirconia

    Directory of Open Access Journals (Sweden)

    A. K. Singh

    2014-01-01

    Full Text Available We report synthesis of ZrO2 nanoparticles (NPs using microwave assisted chemical method at 80°C temperature. Synthesized ZrO2 NPs were calcinated at 400°C under air atmosphere and characterized using FTIR, XRD, SEM, TEM, BET, and EDS for their formation, structure, morphology, size, and elemental composition. XRD results revealed the formation of mixed phase monoclinic and tetragonal ZrO2 phases having crystallite size of the order 8.8 nm from most intense XRD peak as obtained using Scherrer formula. Electron microscope analysis shows that the NPs were less than 10 nm and highly uniform in size having spherical morphology. BET surface area of ZrO2 NPs was found to be 65.85 m2/g with corresponding particle size of 16 nm. The band gap of synthesized NPs was found to be 2.49 eV and PL spectra of ZrO2 synthesized NPs showed strong peak at 414 nm, which corresponds to near band edge emission (UV emission and a relatively weak peak at 475 and 562 nm.

  1. Characterization by spectroscopic Ellipsometry, the physical properties of silver nanoparticles.

    Science.gov (United States)

    Coanga, Jean-Maurice

    2013-04-01

    Physicists are able to change their minds through their experiments. I think it is time to go kick the curse and go further in research if we want a human future. I work in the Nano-Optics and Plasmonics research. I defined with ellipsomètrie the structure of new type of Nano particles of silver. It's same be act quickly to replace the old dirty leaded electronic-connexion chip and by the other hand to find a new way for the heath care of cancer disease by nanoparticles the next killers of bad cells. Silver nanoparticle layers are obtained by Spark Plasma Sintering are investigated as an alternative to lead alloy based material for solder joint in power mechatronics modules. These layers are characterized by mean of conventional techniques that is the dilatometry technique, the resistivity measurement through the van der Pauw method, and the flash laser technique. Furthermore, the nanoparticles of silver layer are deeply studied by UV-Visible spectroscopic ellipsometry. Spectroscopic angles parameters are determined in function of temperature and dielectric constants are deduced and analyzed through an optical model which takes into account a Drude and a Lorentz component within the Bruggeman effective medium approximation (EMA). The relaxation times and the electrical conductivity are plot in function of temperature. The obtained electrical conductivity give significant result in good agreement to those reported by four points electrical measurement method.

  2. Characterization of the variation of the material properties in a freestanding inhomogeneous thin film

    Energy Technology Data Exchange (ETDEWEB)

    Cao Xiaoshan [School of Mechanical Systems Engineering, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju 500-757 (Korea, Republic of); Jin Feng [MOE Key Laboratory for Strength and Vibration, School of Aerospace, Xi' an Jiaotong University, Xi' an 710049 (China); Jeon, Insu, E-mail: i_jeon@chonnam.ac.k [School of Mechanical Systems Engineering, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju 500-757 (Korea, Republic of)

    2010-12-01

    This Letter presents a new technique for measuring the variation of the material properties along the thickness in a freestanding inhomogeneous thin film. The analytical results reveal a simple relation between the material properties and the set of cut-off frequencies of Lamb waves. The influence of the graded properties on the variation of cut-off frequencies in three different kinds of models, including artificial FGM model, sub-surface damage model, and nano-porous thin film model, is discussed. These results provide theoretical guidance for characterizing the material property variations of MEMS/NEMS.

  3. Nanofluid optical property characterization: towards efficient direct absorption solar collectors

    Directory of Open Access Journals (Sweden)

    Otanicar Todd

    2011-01-01

    Full Text Available Abstract Suspensions of nanoparticles (i.e., particles with diameters < 100 nm in liquids, termed nanofluids, show remarkable thermal and optical property changes from the base liquid at low particle loadings. Recent studies also indicate that selected nanofluids may improve the efficiency of direct absorption solar thermal collectors. To determine the effectiveness of nanofluids in solar applications, their ability to convert light energy to thermal energy must be known. That is, their absorption of the solar spectrum must be established. Accordingly, this study compares model predictions to spectroscopic measurements of extinction coefficients over wavelengths that are important for solar energy (0.25 to 2.5 μm. A simple addition of the base fluid and nanoparticle extinction coefficients is applied as an approximation of the effective nanofluid extinction coefficient. Comparisons with measured extinction coefficients reveal that the approximation works well with water-based nanofluids containing graphite nanoparticles but less well with metallic nanoparticles and/or oil-based fluids. For the materials used in this study, over 95% of incoming sunlight can be absorbed (in a nanofluid thickness ≥10 cm with extremely low nanoparticle volume fractions - less than 1 × 10-5, or 10 parts per million. Thus, nanofluids could be used to absorb sunlight with a negligible amount of viscosity and/or density (read: pumping power increase.

  4. Characterization of Triaxial Braided Composite Material Properties for Impact Simulation

    Science.gov (United States)

    Roberts, Gary D.; Goldberg, Robert K.; Biniendak, Wieslaw K.; Arnold, William A.; Littell, Justin D.; Kohlman, Lee W.

    2009-01-01

    The reliability of impact simulations for aircraft components made with triaxial braided carbon fiber composites is currently limited by inadequate material property data and lack of validated material models for analysis. Improvements to standard quasi-static test methods are needed to account for the large unit cell size and localized damage within the unit cell. The deformation and damage of a triaxial braided composite material was examined using standard quasi-static in-plane tension, compression, and shear tests. Some modifications to standard test specimen geometries are suggested, and methods for measuring the local strain at the onset of failure within the braid unit cell are presented. Deformation and damage at higher strain rates is examined using ballistic impact tests on 61- by 61- by 3.2-mm (24- by 24- by 0.125-in.) composite panels. Digital image correlation techniques were used to examine full-field deformation and damage during both quasi-static and impact tests. An impact analysis method is presented that utilizes both local and global deformation and failure information from the quasi-static tests as input for impact simulations. Improvements that are needed in test and analysis methods for better predictive capability are examined.

  5. Synthesis, Characterization and Properties of Nanoparticles of Intermetallic Compounds

    Energy Technology Data Exchange (ETDEWEB)

    DiSalvo, Francis J. [Cornell Univ., Ithaca, NY (United States)

    2015-03-12

    The research program from 2010 to the end of the grant focused on understanding the factors important to the synthesis of single phase intermetallic nano-particles (NPs), their size, crystalline order, surface properties and electrochemical activity. The synthetic method developed is a co-reduction of mixtures of single metal precursors by strong, soluble reducing agents in a non-protic solvent, tetrahydrofuran (THF). With some exceptions, the particles obtained by room temperature reduction are random alloys that need to be annealed at modest temperatures (200 to 600 °C) in order to develop an ordered structure. To avoid significant particle size growth and agglomeration, the particles must be protected by surface coatings. We developed a novel method of coating the metal nanoparticles with KCl, a by-product of the reduction reaction if the proper reducing agents are employed. In that case, a composite product containing individual metal nanoparticles in a KCl matrix is obtained. The composite can be heated to at least 600 °C without significant agglomeration or growth in particle size. Washing the annealed product in the presence of catalyst supports in ethylene glycol removes the KCl and deposits the particles on the support. Six publications present the method and its application to producing and studying new catalyst/support combinations for fuel cell applications. Three publications concern the use of related methods to explore new lithium-sulfur battery concepts.

  6. Structural properties and hyperfine characterization of Sn-substituted goethites

    Energy Technology Data Exchange (ETDEWEB)

    Larralde, A.L. [INQUIMAE, Departamento de Quimica Inorganica, Analitica y Quimica Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (Argentina); Ramos, C.P. [Departamento de Fisica de la Materia Condensada, GIyA - CAC - CNEA, Av. Gral. Paz 1499 (1650), San Martin, Bs. As. (Argentina); Arcondo, B. [Departamento de Fisica, Facultad de Ingenieria, Universidad de Buenos Aires, Av. Paseo Colon 850 (C1063ACV), Bs. As. (Argentina); Tufo, A.E. [INQUIMAE, Departamento de Quimica Inorganica, Analitica y Quimica Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (Argentina); Saragovi, C. [Departamento de Fisica de la Materia Condensada, GIyA - CAC - CNEA, Av. Gral. Paz 1499 (1650), San Martin, Bs. As. (Argentina); Sileo, E.E., E-mail: sileo@qi.fcen.uba.ar [INQUIMAE, Departamento de Quimica Inorganica, Analitica y Quimica Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (Argentina)

    2012-04-16

    Highlights: Black-Right-Pointing-Pointer Pure and tin-doped goethites were synthesized from Sn(II) solutions at ambient pressure and 70 Degree-Sign C. Black-Right-Pointing-Pointer The Rietveld refinement of PXRD data indicated that Sn partially substituted the Fe(III) ions. Black-Right-Pointing-Pointer The substitution provoked unit cell expansion, and a distortion of the coordination polyhedron. Black-Right-Pointing-Pointer {sup 119}Sn Moessbauer spectroscopy revealed that Sn(II) is incorporated as Sn(IV). Black-Right-Pointing-Pointer {sup 57}Fe Moessbauer spectroscopy showed a lower magnetic coupling as tin concentration increased. - Abstract: Tin-doped goethites obtained by a simple method at ambient pressure and 70 Degree-Sign C were characterized by inductively coupled plasma atomic emission spectrometry, scanning electron microscopy, Rietveld refinement of powder X-ray diffraction data, and {sup 57}Fe and {sup 119}Sn Moessbauer spectroscopy. The particles size and the length to width ratios decreased with tin-doping. Sn partially substituted the Fe(III) ions provoking unit cell expansion and increasing the crystallinity of the particles with enlarged domains that grow in the perpendicular and parallel directions to the anisotropic broadening (1 1 1) axis. Intermetallic E, E Prime and DC distances also change although the variations are not monotonous, indicating different variations in the coordination polyhedron. In general, the Sn-substituted samples present larger intermetallic distances than pure goethite, and the greatest change is shown in the E Prime distance which coincides with the c-parameter. {sup 119}Sn Moessbauer spectroscopy revealed that Sn(II) is incorporated as Sn(IV) in the samples. On the other hand, Fe(II) presence was not detected by {sup 57}Fe Moessbauer spectroscopy, suggesting the existence of vacancies in the Sn-doped samples. A lower magnetic coupling is also evidenced from the average magnetic hyperfine field values obtained as tin

  7. Synthesis, characterization, and properties of low-dimensional nanostructured materials

    Science.gov (United States)

    Hu, Xianluo

    2007-05-01

    Nanometer scale structures represent an exciting and rapidly expanding area of research. Studies on new physical/chemical properties and applications of nanomaterials and nanostructures are possible only when nanostructured materials are made available with desired size, morphology, crystal and microstructure, and composition. Thus, controlled synthesis of nanomaterials is the essential aspect of nanotechnology. This thesis describes the development of simple and versatile solution-based approaches to synthesize low-dimensional nanostructures. The first major goal of this research is to design and fabricate morphology-controlled alpha-Fe 2O3 nanoarchitectures in aqueous solution through a programmed microwave-assisted hydrothermal route, taking advantage of microwave irradiation and hydrothermal effects. Free-standing alpha-Fe2O3 nanorings are prepared by hydrolysis of FeCl3 in the presence of phosphate ions. The as-formed architecture of alpha-Fe2O 3 nanorings is an exciting new member in the family of iron oxide nanostructures. Our preliminary results demonstrate that sensors made of the alpha-Fe 2O3 nanorings exhibit high sensitivity not only for bio-sensing of hydrogen peroxide in a physiological solution but also for gas-sensing of alcohol vapor at room temperature. Moreover, monodisperse alpha-Fe 2O3 nanocrystals with continuous aspect-ratio tuning and fine shape control are achieved by controlling the experimental conditions. The as-formed alpha-Fe2O3 exhibits shape-dependent infrared optical properties. The growth process of colloidal alpha-Fe 2O3 crystals in the presence of phosphate ions is discussed. In addition, through an efficient microwave-assisted hydrothermal process, self-assembled hierarchical alpha-Fe2O3 nanoarchitectures are synthesized on a large scale. The second major goal of this research is to develop convenient microwave-hydrothermal approaches for the fabrication of carbon-based nanocomposites: (1) A one-pot solution-phase route, namely

  8. Characterization of concrete properties from dielectric properties using ground penetrating radar

    International Nuclear Information System (INIS)

    This paper presents the experimental results of a study of the relationships between light-weight (LWAC) and normal aggregate concrete (NAC) properties, as well as radar wave properties that are derived by using ground penetrating radar (GPR). The former (LWAC) refers to compressive strength, apparent porosity and saturated density, while the latter (NAC) refers to real part of dielectric permittivity (ε' or real permittivity) and wave energy level (E). Throughout the test period of the newly cast concrete cured for 90 days, the above mentioned material properties gradually changed which can be attributed to the effects of cement hydration, different types of aggregates and initial water to binder ratios. A number of plots describing various properties of concrete such as dielectric, strength and porosity perspectives were established. From these plots, we compare the characteristics of how much and how fast free water was turned to absorbed water in LWAC and NAC. The underlying mechanisms and a mechanistic model are then developed.

  9. Role of the advanced microstructures characterization in modeling of mechanical properties of AHSS steels

    Energy Technology Data Exchange (ETDEWEB)

    Radwański, Krzysztof, E-mail: kradwanski@imz.pl; Wrożyna, Andrzej, E-mail: awrozyna@imz.pl; Kuziak, Roman, E-mail: rkuziak@imz.pl

    2015-07-15

    Detailed knowledge of the fraction, morphology and chemical composition of phase constituents and their effect on the mechanical properties play a crucial role in understanding of the mechanisms influencing the properties of Advanced High Strength Steels (AHSS). On the other hand, the most important microstructural features of these steels are characterized by different size, starting from the nano- and ending on the microscale. Therefore, a detailed characterization of the AHSS microstructure must involve many methods capable of tracing the microstructure at different scale levels. The paper presents selected capabilities of advanced analytical techniques, in combination with conventional light optical microscopy (LOM), for quantitative characterization of the microstructure developed in AHSS steels during thermomechanical processing or continuous annealing. The material used for the investigation comprised the samples of DP steel sheet produced at the industrial scale. Special emphasis was focused on the capabilities of the Field Emission Gun Scanning Electron Microscopy (FEG SEM) combined with EBSD of microstructural characterization. The significance of accurate microstructure characterization for the modeling of mechanical properties of AHSS steels was demonstrated for the case of numerical calculation of the stress–strain curve in the standard tensile test. The work results indicate that such an engineering approach is useful for prediction of material properties.

  10. On the elastic properties of carbon nanotube-based composites: modelling and characterization

    CERN Document Server

    Thostenson, E T

    2003-01-01

    The exceptional mechanical and physical properties observed for carbon nanotubes has stimulated the development of nanotube-based composite materials, but critical challenges exist before we can exploit these extraordinary nanoscale properties in a macroscopic composite. At the nanoscale, the structure of the carbon nanotube strongly influences the overall properties of the composite. The focus of this research is to develop a fundamental understanding of the structure/size influence of carbon nanotubes on the elastic properties of nanotube-based composites. Towards this end, the nanoscale structure and elastic properties of a model composite system of aligned multi-walled carbon nanotubes embedded in a polystyrene matrix were characterized, and a micromechanical approach for modelling of short fibre composites was modified to account for the structure of the nanotube reinforcement to predict the elastic modulus of the nanocomposite as a function of the constituent properties, reinforcement geometry and nanot...

  11. Characterizing Roughness and Connectivity Properties of Aquifer Conductivity Using the Method of Anchored Distributions (MAD)

    Science.gov (United States)

    Hesse, F.; Sege, J. E.; Murillo, C.; Attinger, S.; Rubin, Y.

    2014-12-01

    The conductivity of aquifers is usually hard to represent in a precise manner due to having a high degree of spatial variability combined with a scarcity of information. As a result, such conductivity fields are commonly modeled as a random field, defined by its expectation value and the variogram function. This variogram is usually parametrized by fitting a model functions to an experimental variogram derived from point measurements of said conductivity. In this study, we investigate properties of such conductivity fields, that are hard to detect using such classic characterization schemes. The first property is roughness, which can be modeled by the flexible Matern function. The second property is connectivity, which has a strong impact on flow and transport behavior. These two properties are hard to characterize from point measurements alone. As a result, it is necessary to use additional data. Therefore, we use the Method of Anchored Distributions (MAD), which is a novel Bayesian tool for the inverse characterization of random fields. MAD is versatile with respect to the used data and does not assume any formal relationship between the target variable, i.e. the log hydraulic conductivity, and the data used for the inversion process, e.g. head measurements, drawdown from pumping tests or break-through curves of a tracer. With respect to the characterization of the aforementioned properties, we investigate the impact of several factors on their identifiability, including alternative and complementary data types, the necessary amount of data, where to collect this data or how to assimilate it.

  12. Characterizing the Absorption Properties for Remote Sensing of Three Small Optically-Diverse South African Reservoirs

    OpenAIRE

    Mark William Matthews; Stewart Bernard

    2013-01-01

    Characterizing the specific inherent optical properties (SIOPs) of water constituents is fundamental to remote sensing applications. Therefore, this paper presents the absorption properties of phytoplankton, gelbstoff and tripton for three small, optically-diverse South African inland waters. The three reservoirs,  Hartbeespoort, Loskop and Theewaterskloof, are challenging for remote sensing, due to differences in phytoplankton assemblage and the considerable range of constituent concentratio...

  13. Characterization of the Radiation Shielding Properties of US and Russian EVA Suits

    OpenAIRE

    Benton, E.R.; Benton, E.V.; Frank, A L

    2001-01-01

    Reported herein are results from the Eril Research, Inc. (ERI) participationin the NASA Johnson Space Center sponsored study characterizing the radiation shielding properties of the two types of space suit that astronauts are wearing during the EVA on-orbit assembly of the International Space Station (ISS). Measurements using passive detectors were carried out to assess the shielding properties of the US EMU Suit and the Russian Orlan-M suit during irradiations of the suits and a tissue ...

  14. Properties Correlations and Characterization of Athabasca Oil Sands-derived Synthetic Crude Oil

    Institute of Scientific and Technical Information of China (English)

    Wang Jun; Zhao Suoqi; Xu Chunming; Chung Keng H.

    2007-01-01

    Narrow fractions of Athabasca oil sands-derived synthetic crude oil (SCO) from Canada were obtained by distillation at 20 ℃ to 500 ℃ and characterized. The yield and properties, such as density, refractive index, viscosity,freezing point, sulfur and nitrogen content and UOP K-index, were correlated as a function of boiling temperature (Tb).The properties of naphtha fractions, jet fuel and diesel fractions could be predicted accurately with the correlations, which are useful for process design considerations, such as optimizing operating conditions of refinery processing units. The other key properties and characteristics of naphtha fractions, jet fuel, diesel and vacuum gas oil were also determined.

  15. Thermo-Mechanical FE Simulation & Characterization of MoGr’s Elastic Properties

    CERN Document Server

    de Bras de Fer, Thibault

    2014-01-01

    This report summarizes a two-month’s internship within the EN-MME department, focusing on Finite Element simulations for the Collimation project and PSB H0/H- dump upgrade, and the progress done on the characterization of Molybdenum-Graphite elastic properties.

  16. Characterization of Different Parts of Oil Palm Fronds (Elaeis Guineensis and Its Properties

    Directory of Open Access Journals (Sweden)

    Noor Afeefah Nordin

    2016-01-01

    Full Text Available The study was conducted on characterizing the properties of oil palm fronds (Elaeis guineensis from different parts. The fronds were cut to three parts which were the top, middle and bottom. The samples were chipped, dried in the oven of 50 °C and ground before they were characterized. The properties of the fronds were characterized using thermal gravimetric analyser (TGA, fourier transform infrared spectroscopy (FTIR and x-ray diffraction (XRD. The results from TGA showed that the bottom part of the frond had the lowest percentage of residues which was 29.22 % and the degradation temperature was 194.17 °C. The FTIR spectra showed almost similar peaks for all samples. The bottom part of the frond had the highest crystallinity index which was 35.26 %. The study proved that different parts of the frond had different characteristics due to its chemical compositions.

  17. The Quest for A Characterization of Hom-Properties of Finite Character

    Directory of Open Access Journals (Sweden)

    Broere Izak

    2016-05-01

    Full Text Available A graph property is a set of (countable graphs. A homomorphism from a graph G to a graph H is an edge-preserving map from the vertex set of G into the vertex set of H; if such a map exists, we write G → H. Given any graph H, the hom-property →H is the set of H-colourable graphs, i.e., the set of all graphs G satisfying G → H. A graph property P is of finite character if, whenever we have that F ∈ P for every finite induced subgraph F of a graph G, then we have that G ∈ P too. We explore some of the relationships of the property attribute of being of finite character to other property attributes such as being finitely-induced-hereditary, being finitely determined, and being axiomatizable. We study the hom-properties of finite character, and prove some necessary and some sufficient conditions on H for →H to be of finite character. A notable (but known sufficient condition is that H is a finite graph, and our new model-theoretic proof of this compactness result extends from hom-properties to all axiomatizable properties. In our quest to find an intrinsic characterization of those H for which →H is of finite character, we find an example of an infinite connected graph with no finite core and chromatic number 3 but with hom-property not of finite character.

  18. Microscale characterization of the viscoelastic properties of hydrogel biomaterials using dual-mode ultrasound elastography.

    Science.gov (United States)

    Hong, Xiaowei; Stegemann, Jan P; Deng, Cheri X

    2016-05-01

    Characterization of the microscale mechanical properties of biomaterials is a key challenge in the field of mechanobiology. Dual-mode ultrasound elastography (DUE) uses high frequency focused ultrasound to induce compression in a sample, combined with interleaved ultrasound imaging to measure the resulting deformation. This technique can be used to non-invasively perform creep testing on hydrogel biomaterials to characterize their viscoelastic properties. DUE was applied to a range of hydrogel constructs consisting of either hydroxyapatite (HA)-doped agarose, HA-collagen, HA-fibrin, or preosteoblast-seeded collagen constructs. DUE provided spatial and temporal mapping of local and bulk displacements and strains at high resolution. Hydrogel materials exhibited characteristic creep behavior, and the maximum strain and residual strain were both material- and concentration-dependent. Burger's viscoelastic model was used to extract characteristic parameters describing material behavior. Increased protein concentration resulted in greater stiffness and viscosity, but did not affect the viscoelastic time constant of acellular constructs. Collagen constructs exhibited significantly higher modulus and viscosity than fibrin constructs. Cell-seeded collagen constructs became stiffer with altered mechanical behavior as they developed over time. Importantly, DUE also provides insight into the spatial variation of viscoelastic properties at sub-millimeter resolution, allowing interrogation of the interior of constructs. DUE presents a novel technique for non-invasively characterizing hydrogel materials at the microscale, and therefore may have unique utility in the study of mechanobiology and the characterization of hydrogel biomaterials. PMID:26928595

  19. Aerosol Characterization and New Instrumentation for Better Understanding Snow Radiative Properties

    Science.gov (United States)

    Beres, N. D.

    2015-12-01

    Snow albedo is determined by snowpack thickness and grain size, but also affected by contamination with light-absorbing, microscopic (e.g., mineral dust, combustion aerosols, bio-aerosols) and macroscopic (e.g., microalgae, plant debris, sand, organisms) compounds. Most currently available instruments for measuring snow albedo utilize the natural, downward flux of solar radiation and the reflected upward flux. This reliance on solar radiation (and, thus, large zenith angles and clear-sky conditions) leads to severe constraints, preventing characterization of detailed diurnal snow albedo cycles. Here, we describe instrumentation and methodologies to address these limitations with the development and deployment of new snow radiation sensors for measuring surface spectral and in-snow radiative properties. This novel instrumentation will be tested at the CRREL/UCSB Eastern Sierra (CUES) Snow Study Site at Mammoth Mountain, which is extensively instrumented for characterizing snow properties including snow albedo and surface morphology. However, it has been lacking instrumentation for the characterization of aerosols that can be deposited on the snow surface through dry and wet deposition. Currently, we are installing aerosol instrumentation at the CUES site, which are also described. This includes instruments for the multi-wavelength measurement of aerosol scattering and absorption coefficients and for the characterization of aerosol size distribution. Knowledge of aerosol concentration and physical and optical properties will allow for the study of aerosol deposition and modification of snow albedo and for establishing an aerosol climatology for the CUES site.

  20. Characterization and Design of Zeolite Catalysts Solid Acidity, Shape Selectivity and Loading Properties

    CERN Document Server

    Niwa, Miki; Okumura, Kazu

    2010-01-01

    Zeolites are microporous, aluminosilicate minerals commonly used as commercial adsorbents. Zeolite-based catalysts are used by industrial chemical companies in the interconversion of hydrocarbons and the alkylation of aromatic compounds. The current book deals with the characterization of specific properties of Zeolites and calculations for the design of catalysts. Measurements and utilization of solid acidity, shape selectivity, and loading properties, that are three prominent properties of a Zeolite catalyst, are treated in detail. These features concern chemical vapor deposition of silica, shape selectivity, loading properties, solid activity, Brønsted or Lewis character, ammonia temperature programmed desorption, control of the pore-opening size by chemical vapor deposition of silica and XAFS analysis of metals being highly dispersed inside and outside a framework.

  1. Synthesis, characterization and properties of polyaniline/expanded vermiculite intercalated nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Lin Jianming; Tang Qunwei; Wu Jihuai; Sun Hui [Key Laboratory of Functional Materials for Fujian Higher Education, Institute of Material Physical Chemistry, Huaqiao University, Quanzhou 362021 (China)], E-mail: jhwu@hqu.edu.cn

    2008-04-15

    The synthesis characterization and conductivities of polyaniline/expanded vermiculite intercalated nanocomposite are presented in this paper. The conductive emeraldine salt form of polyaniline is inserted into the interlayer of expanded vermiculite to produce the nanocomposite with high conductivity. The structures and properties are characterized by transmission electron microscopy x-ray diffraction spectroscopy fourier transform infrared spectroscopy thermogravimetry analysis and by the measurements of conductivity and stability. The results show that an intercalated nanocomposite with high conductivity and stability is obtained. The synthesis conditions are optimized to obtain the highest conductivity which is 6.80 S cm{sup -1}.

  2. Synthesis, characterization and properties of polyaniline/expanded vermiculite intercalated nanocomposite

    Directory of Open Access Journals (Sweden)

    Jianming Lin, Qunwei Tang, Jihuai Wu and Hui Sun

    2008-01-01

    Full Text Available The synthesis characterization and conductivities of polyaniline/expanded vermiculite intercalated nanocomposite are presented in this paper. The conductive emeraldine salt form of polyaniline is inserted into the interlayer of expanded vermiculite to produce the nanocomposite with high conductivity. The structures and properties are characterized by transmission electron microscopy x-ray diffraction spectroscopy fourier transform infrared spectroscopy thermogravimetry analysis and by the measurements of conductivity and stability. The results show that an intercalated nanocomposite with high conductivity and stability is obtained. The synthesis conditions are optimized to obtain the highest conductivity which is 6.80 S cm−1.

  3. TCNQ-embedded heptacene and nonacene: Synthesis, characterization and physical properties

    KAUST Repository

    Ye, Qun

    2013-01-01

    Incorporation of 7,7,8,8-tetracyanoquinodimethane (TCNQ) moieties into the acene backbone has been successfully achieved and two heptacene-TCNQ derivatives and one nonacene-TCNQ derivative have been synthesized and well characterized. Two TCNQ moieties have been embedded into heptacene and nonacene backbones for the first time. All the three compounds have good stability and solubility due to the presence of TCNQ moieties. Single crystal analysis revealed a bent butterfly-like conformation of these molecules. Their charge transport properties have been characterized using organic field effect transistors (OFETs). © 2013 The Royal Society of Chemistry.

  4. Development of Characterization Techniques of Thermodynamic and Physical Properties Applied to the CO2-DMSO Mixture

    OpenAIRE

    Calvignac, Brice; Rodier, Elisabeth; Letourneau, Jean-Jacques; Fages, Jacques

    2009-01-01

    International audience This work is focused on the development of new characterization techniques of physical and thermodynamic properties. These techniques have been validated using the binary system DMSO-CO2 for which several studies of characterization have been well documented. We focused on the DMSO-rich phase and we carried out measurements of volumetric expansion, density, viscosity and CO2 solubility at 298.15, 308.15 and 313.15 K and pressures up to 9 MPa. The experimental procedu...

  5. A Statistics-Based Material Property Analysis to Support TPS Characterization

    Science.gov (United States)

    Copeland, Sean R.; Cozmuta, Ioana; Alonso, Juan J.

    2012-01-01

    Accurate characterization of entry capsule heat shield material properties is a critical component in modeling and simulating Thermal Protection System (TPS) response in a prescribed aerothermal environment. The thermal decomposition of the TPS material during the pyrolysis and charring processes is poorly characterized and typically results in large uncertainties in material properties as inputs for ablation models. These material property uncertainties contribute to large design margins on flight systems and cloud re- construction efforts for data collected during flight and ground testing, making revision to existing models for entry systems more challenging. The analysis presented in this work quantifies how material property uncertainties propagate through an ablation model and guides an experimental test regimen aimed at reducing these uncertainties and characterizing the dependencies between properties in the virgin and charred states for a Phenolic Impregnated Carbon Ablator (PICA) based TPS. A sensitivity analysis identifies how the high-fidelity model behaves in the expected flight environment, while a Monte Carlo based uncertainty propagation strategy is used to quantify the expected spread in the in-depth temperature response of the TPS. An examination of how perturbations to the input probability density functions affect output temperature statistics is accomplished using a Kriging response surface of the high-fidelity model. Simulations are based on capsule configuration and aerothermal environments expected during the Mars Science Laboratory (MSL) entry sequence. We identify and rank primary sources of uncertainty from material properties in a flight-relevant environment, show the dependence on spatial orientation and in-depth location on those uncertainty contributors, and quantify how sensitive the expected results are.

  6. Novel polymeric potassium complex: Its synthesis, structural characterization, photoluminescence and electrochemical properties

    International Nuclear Information System (INIS)

    In this paper, we obtained a novel poly(vanillinato potassium) complex (PVP) as a single crystal and characterized by analytical and spectroscopic methods. A single crystal of the PVP was obtained from the acetone solution. X-ray structural data show that crystals contain polymeric K+ complex of vanillin. Each potassium ion in the polymeric structure is identical and seven-coordinate, bonded to two methoxy, two phenoxy and three aldehyde oxygen atoms from four vaniline molecules. Two aldehyde oxygen atoms are bridging between potassium ions. It crystallizes in the monoclinic system, space group P21/c, with lattice parameters a=9.6215(10) Å, b=17.4139(19) Å, c=9.6119(10) Å, β=100.457(2)° and Z=4. Thermal properties of the PVP were investigated by TGA, DTA and DSC methods. The electrochemical properties of the complex were studied in different solvents and at various scan rates. The luminescence properties of the complex in different solvents and at different pH values have been investigated. The results show that the complex exhibits more efficient luminescence property in CH3CN and n-butanol. - Highlights: ► Novel polymeric potassium complex was prepared and fully characterized. ► X-ray crystal structure of complex was reported. ► Electrochemical properties of compound were investigated. ► Thermal and DSC measurements of complex were examined.

  7. Novel polymeric potassium complex: Its synthesis, structural characterization, photoluminescence and electrochemical properties

    Energy Technology Data Exchange (ETDEWEB)

    Ceyhan, Goekhan [Chemistry Department, K.Maras Suetcue Imam University, 46100 K.Maras (Turkey); Tuemer, Mehmet, E-mail: mtumer@ksu.edu.tr [Chemistry Department, K.Maras Suetcue Imam University, 46100 K.Maras (Turkey); Koese, Muhammet; McKee, Vickie [Chemistry Department, Loughborough University, LE11 3TU Leicestershire (United Kingdom)

    2012-03-15

    In this paper, we obtained a novel poly(vanillinato potassium) complex (PVP) as a single crystal and characterized by analytical and spectroscopic methods. A single crystal of the PVP was obtained from the acetone solution. X-ray structural data show that crystals contain polymeric K{sup +} complex of vanillin. Each potassium ion in the polymeric structure is identical and seven-coordinate, bonded to two methoxy, two phenoxy and three aldehyde oxygen atoms from four vaniline molecules. Two aldehyde oxygen atoms are bridging between potassium ions. It crystallizes in the monoclinic system, space group P2{sub 1}/c, with lattice parameters a=9.6215(10) A, b=17.4139(19) A, c=9.6119(10) A, {beta}=100.457(2) Degree-Sign and Z=4. Thermal properties of the PVP were investigated by TGA, DTA and DSC methods. The electrochemical properties of the complex were studied in different solvents and at various scan rates. The luminescence properties of the complex in different solvents and at different pH values have been investigated. The results show that the complex exhibits more efficient luminescence property in CH{sub 3}CN and n-butanol. - Highlights: Black-Right-Pointing-Pointer Novel polymeric potassium complex was prepared and fully characterized. Black-Right-Pointing-Pointer X-ray crystal structure of complex was reported. Black-Right-Pointing-Pointer Electrochemical properties of compound were investigated. Black-Right-Pointing-Pointer Thermal and DSC measurements of complex were examined.

  8. Pi-Extended Diindole-Fused Azapentacenone: Synthesis, Characterization, and Photophysical and Lithium-Storage Properties.

    Science.gov (United States)

    Zhao, Jianfeng; Li, Renping; Ai, Wei; Dong, Dai; Li, Jiewei; Chen, Lin; Xie, Linghai; Yu, Ting; Huang, Wei

    2016-05-01

    Pi-extended polyaromatics tend to exhibit improved electronic properties with respect to the intrinsic structures. Herein, the rational design of a π-extended diindole-fused diazapentacenone (IP), with a nine-ring-fused core, obtained by applying an intramolecular Friedel-Crafts diacylation synthetic routine, is reported. The chemical structure, physical properties, and morphology of IP were fully characterized. Serving as an organic cathode material for a lithium-ion battery, the as-prepared nanorods of π-extended IP display higher conductivity and superior electrochemical performance than those of the naked diazapentacenone without diindole fusion. PMID:26717256

  9. Characterization of heterogeneity and nonlinearity in material properties of nuclear graphite using an inverse method

    International Nuclear Information System (INIS)

    A finite-element-based inverse method has been developed to allow the characterization of the heterogeneity and nonlinearity in material properties of isotropic nuclear graphite using a single experimental test. The method is implemented into the commercial finite element code ABAQUS using its User Material (UMAT) Subroutine for ease of application. The program has been verified using simulated examples with idealized distributions of elastic modulus and the results showed rapid convergence with good accuracy. Finally, the method was applied to actual mechanical testing of nuclear graphite for which the heterogeneous distribution and nonlinearity of material properties were evaluated

  10. An updated taxonomy for characterizing hackers according to their threat properties

    DEFF Research Database (Denmark)

    Hald, Sara Ligaard; Pedersen, Jens Myrup

    2012-01-01

    The objective of this paper is to give an up-to-date terminology for and categorization of hackers on the Internet, and to characterize each category of hackers by their threat properties. To be able to prioritize defense efforts, security experts need an accurate taxonomy of attackers for the...... production of detailed and precise threat assessments. We take an existing taxonomy for hackers and update it to correspond to the terminology used by hackers and security experts. Also, the categories of hackers are updated to reflect the threat properties demonstrated in recent attacks, and each category...

  11. An expert system to characterize the surface morphological properties according to their functionalities

    International Nuclear Information System (INIS)

    In this paper we propose a new methodology to characterize the morphological properties of a surface in relation with its functionality (tribological properties, surface coating adhesion, brightness, wettability...). We create a software based on experimental design and surface profile recording. Using an appropriate database structure, the roughness parameters are automatically computed at different scales. The surface files are saved in a hard disk directory and roughness parameters are computed at different scales. Finally, a statistical analysis system proposes the roughness parameter (or the pair of roughness parameters) that better describe(s) the functionality of the surface and the spatial scales at which the parameter(s) is (are) the more relevant.

  12. HEAT-RESISTANT PYRIDINE-BASED POLY(ETHER-ESTER)S: SYNTHESIS,CHARACTERIZATION AND PROPERTIES

    Institute of Scientific and Technical Information of China (English)

    Shahram Mehdipour-Ataei; Ali Mahmoodi

    2013-01-01

    A pyridine-based diacid was synthesized via nucleophilic substitution reaction of 4-hydroxy benzoic acid with 2,6-dichloropyridine in the presence of potassium carbonate.The diacid was characterized using FT-IR and 1H-NMR spectroscopic methods and also with elemental analysis.Polycondensation reaction of the diacid with different diols including 1,4-dihydroxy benzene,1,5-dihydroxy naphthalene,bis-phenol A and bis-phenol-P resulted in preparation of pyridine-based poly(ether-ester)s.The polymers were characterized and their physical and thermal properties including inherent viscosity,molecular weight,solubility,thermal stability,thermal behavior and crystallinity were studied.They revealed high heat-resistance and improved solubility in polar solvents.Structure-property relations for the prepared polyester were also studied.

  13. Characterization of thermochemical properties of Al nanoparticle and NiO nanowire composites

    OpenAIRE

    Wen, John Z.; Ringuette, Sophie; Bohlouli-Zanjani, Golnaz; Hu, Anming; Nguyen, Ngoc Ha; Persic, John; Petre, Catalin F; Zhou, Y. Norman

    2013-01-01

    Thermochemical properties and microstructures of the composite of Al nanoparticles and NiO nanowires were characterized. The nanowires were synthesized using a hydrothermal method and were mixed with these nanoparticles by sonication. Electron microscopic images of these composites showed dispersed NiO nanowires decorated with Al nanoparticles. Thermal analysis suggests the influence of NiO mass ratio was insignificant with regard to the onset temperature of the observed thermite reaction, al...

  14. Photoelectrochemical characterization and photocatalytic properties of mesoporous TiO2/ZrO2 films

    OpenAIRE

    Natalie Smirnova; Yuriy Gnatyuk; Anna Eremenko; Gennadiy Kolbasov; Vera Vorobetz; Irina Kolbasova; Olga Linyucheva

    2006-01-01

    Optically transparent, crack-free mesoporous titania and zirconia-doped titania thin film photocatalysts were fabricated by sol-gel technique, using nonionic amphiphilic block copolymer Pluronic P123 as template. The structural and optical properties of these films were characterized using SEM, low-angle XRD, and UV/Vis spectroscopy, hexane adsorption investigation. Band gap energy and the position of flatband potentials were estimated by photoelectrochemical measurements...

  15. Characterization of Anticancer, Antimicrobial, Antioxidant Properties and Chemical Compositions of Peperomia Pellucida Leaf Extract

    OpenAIRE

    Desy Fitrya Syamsumir; Julius Yong Fu Siong; Wendy Wee; Lee Seong Wei

    2011-01-01

    Peperomia pellucida leaf extract was characterized for its anticancer, antimicrobial, antioxidant activities, and chemical compositions. Anticancer activity of P. pellucida leaf extract was determined through Colorimetric MTT (tetrazolium) assay against human breast adenocarcinoma (MCF-7) cell line and the antimicrobial property of the plant extract was revealed by using two-fold broth micro-dilution method against 10 bacterial isolates. Antioxidant activity of the plant extract was then char...

  16. Characterization of Physical and Structural Properties of Brass Powder After Biofield Treatment

    OpenAIRE

    Trivedi, Mahendra; Nayak, Gopal

    2015-01-01

    Brass, a copper-zinc (Cu-Zn) alloy has gained extensive attention in industries due to its high corrosion resistance, machinability and strength to weight ratio. The aim of present study was to evaluate the effect of biofield treatment on structural and physical properties of brass powder. The brass powder sample was divided into two parts: control and treated. The treated part was subjected to Mr.Trivedi’s biofield treatment. Control and treated brass powder were characterized using particle...

  17. Characterization of Physical and Structural Properties of Brass Powder After Biofield Treatment

    OpenAIRE

    Trivedi, Mahendra Kumar

    2015-01-01

    Brass, a copper-zinc (Cu-Zn) alloy has gained extensive attention in industries due to its high corrosion resistance, machinability and strength to weight ratio. The aim of present study was to evaluate the effect of biofield treatment on structural and physical properties of brass powder. The brass powder sample was divided into two parts: control and treated. The treated part was subjected to Mr.Trivedi’s biofield treatment. Control and treated brass powder were characterized using pa...

  18. Characterization of Physical and Thermal Properties of Biofield Treated Neopentyl glycol

    OpenAIRE

    Mahendra Kumar Trivedi; Alice Branton; Dahryn Trivedi; Gopal Nayak

    2015-01-01

    Neopentyl glycol (NPG) has been extensively used as solid-solid phase change materials (PCMs) for thermal energy storage applications. The objective of the present study was to evaluate the impact of biofield treatment on physical, spectral and thermal properties of NPG. The study was performed in two groups (control and treated). The control group remained as untreated, and treatment group was subjected to Mr. Trivedi’s biofield treatment. The control and treated NPG were characterized...

  19. Synthesis, characterization and luminescent properties of lanthanide complexes with an unsymmetrical tripodal ligand

    International Nuclear Information System (INIS)

    Solid complexes of lanthanide nitrates with a new unsymmetrical tripodal ligand, bis[(2'-benzylaminoformyl)phenoxyl)ethyl](ethyl)amine (L) have been synthesized and characterized by elemental analysis, infrared spectra and molar conductivity measurements. At the same time, the luminescent properties of the Sm(III), Eu(III), Tb(III) and Dy(III) nitrate complexes in solid state were also investigated. Under the excitation of UV light, these complexes exhibited characteristic emission of central metal ions

  20. Contact lens physical properties and lipid deposition in a novel characterized artificial tear solution

    OpenAIRE

    Lorentz, Holly; Heynen, Miriam; Kay, Lise M.M.; Dominici, Claudia Yvette; Khan, Warda; Ng, Wendy W.S.; Jones, Lyndon

    2011-01-01

    Purpose To characterize various properties of a physiologically-relevant artificial tear solution (ATS) containing a range of tear film components within a complex salt solution, and to measure contact lens parameters and lipid deposition of a variety of contact lens materials after incubation in this ATS. Methods A complex ATS was developed that contains a range of salts, proteins, lipids, mucin, and other tear film constituents in tear-film relevant concentrations. This ATS was tested to co...

  1. Multi-property characterization chamber for geophysical-hydrological investigations of hydrate bearing sediments.

    Science.gov (United States)

    Seol, Yongkoo; Choi, Jeong-Hoon; Dai, Sheng

    2014-08-01

    With the increase in the interest of producing natural gas from methane hydrates as well as potential risks of massive hydrate dissociation in the context of global warming, studies have recently shifted from pure hydrate crystals to hydrates in sediments. Such a research focus shift requires a series of innovative laboratory devices that are capable of investigating various properties of hydrate-bearing sediments (HBS). This study introduces a newly developed high pressure testing chamber, i.e., multi-property characterization chamber (MPCC), that allows simultaneous investigation of a series of fundamental properties of HBS, including small-strain stiffness (i.e., P- and S-waves), shear strength, large-strain deformation, stress-volume responses, and permeability. The peripheral coolant circulation system of the MPCC permits stable and accurate temperature control, while the core holder body, made of aluminum, enables X-ray computer tomography scanning to be easily employed for structural and morphological characterization of specimens. Samples of hydrate-bearing sediments are held within a rubber sleeve inside the chamber. The thick sleeve is more durable and versatile than thin membranes while also being much softer than oedometer-type chambers that are incapable of enabling flow tests. Bias introduced by the rubber sleeve during large deformation tests are also calibrated both theoretically and experimentally. This system provides insight into full characterization of hydrate-bearing sediments in the laboratory, as well as pressure core technology in the field. PMID:25173288

  2. Multi-property characterization chamber for geophysical-hydrological investigations of hydrate bearing sediments

    International Nuclear Information System (INIS)

    With the increase in the interest of producing natural gas from methane hydrates as well as potential risks of massive hydrate dissociation in the context of global warming, studies have recently shifted from pure hydrate crystals to hydrates in sediments. Such a research focus shift requires a series of innovative laboratory devices that are capable of investigating various properties of hydrate-bearing sediments (HBS). This study introduces a newly developed high pressure testing chamber, i.e., multi-property characterization chamber (MPCC), that allows simultaneous investigation of a series of fundamental properties of HBS, including small-strain stiffness (i.e., P- and S-waves), shear strength, large-strain deformation, stress-volume responses, and permeability. The peripheral coolant circulation system of the MPCC permits stable and accurate temperature control, while the core holder body, made of aluminum, enables X-ray computer tomography scanning to be easily employed for structural and morphological characterization of specimens. Samples of hydrate-bearing sediments are held within a rubber sleeve inside the chamber. The thick sleeve is more durable and versatile than thin membranes while also being much softer than oedometer-type chambers that are incapable of enabling flow tests. Bias introduced by the rubber sleeve during large deformation tests are also calibrated both theoretically and experimentally. This system provides insight into full characterization of hydrate-bearing sediments in the laboratory, as well as pressure core technology in the field

  3. Innovative Field Methods for Characterizing the Hydraulic Properties of a Complex Fractured Rock Aquifer (Ploemeur, Brittany)

    Science.gov (United States)

    Bour, O.; Le Borgne, T.; Longuevergne, L.; Lavenant, N.; Jimenez-Martinez, J.; De Dreuzy, J. R.; Schuite, J.; Boudin, F.; Labasque, T.; Aquilina, L.

    2014-12-01

    Characterizing the hydraulic properties of heterogeneous and complex aquifers often requires field scale investigations at multiple space and time scales to better constrain hydraulic property estimates. Here, we present and discuss results from the site of Ploemeur (Brittany, France) where complementary hydrological and geophysical approaches have been combined to characterize the hydrogeological functioning of this highly fractured crystalline rock aquifer. In particular, we show how cross-borehole flowmeter tests, pumping tests and frequency domain analysis of groundwater levels allow quantifying the hydraulic properties of the aquifer at different scales. In complement, we used groundwater temperature as an excellent tracer for characterizing groundwater flow. At the site scale, measurements of ground surface deformation through long-base tiltmeters provide robust estimates of aquifer storage and allow identifying the active structures where groundwater pressure changes occur, including those acting during recharge process. Finally, a numerical model of the site that combines hydraulic data and groundwater ages confirms the geometry of this complex aquifer and the consistency of the different datasets. The Ploemeur site, which has been used for water supply at a rate of about 106 m3 per year since 1991, belongs to the French network of hydrogeological sites H+ and is currently used for monitoring groundwater changes and testing innovative field methods.

  4. Characterization of Mechanical Properties of Tissue Scaffolds by Phase Contrast Imaging and Finite Element Modeling.

    Science.gov (United States)

    Bawolin, Nahshon K; Dolovich, Allan T; Chen, Daniel X B; Zhang, Chris W J

    2015-08-01

    In tissue engineering, the cell and scaffold approach has shown promise as a treatment to regenerate diseased and/or damaged tissue. In this treatment, an artificial construct (scaffold) is seeded with cells, which organize and proliferate into new tissue. The scaffold itself biodegrades with time, leaving behind only newly formed tissue. The degradation qualities of the scaffold are critical during the treatment period, since the change in the mechanical properties of the scaffold with time can influence cell behavior. To observe in time the scaffold's mechanical properties, a straightforward method is to deform the scaffold and then characterize scaffold deflection accordingly. However, experimentally observing the scaffold deflection is challenging. This paper presents a novel study on characterization of mechanical properties of scaffolds by phase contrast imaging and finite element modeling, which specifically includes scaffold fabrication, scaffold imaging, image analysis, and finite elements (FEs) modeling of the scaffold mechanical properties. The innovation of the work rests on the use of in-line phase contrast X-ray imaging at 20 KeV to characterize tissue scaffold deformation caused by ultrasound radiation forces and the use of the Fourier transform to identify movement. Once deformation has been determined experimentally, it is then compared with the predictions given by the forward solution of a finite element model. A consideration of the number of separate loading conditions necessary to uniquely identify the material properties of transversely isotropic and fully orthotropic scaffolds is also presented, along with the use of an FE as a form of regularization. PMID:25902011

  5. Synthesis and Characterization of Imide Containing Hybrid Epoxy Resin with Improved Mechanical and Thermal Properties

    Directory of Open Access Journals (Sweden)

    U. G. Rane

    2014-01-01

    Full Text Available Phosphorous containing amine, tripropyldiamine phosphine oxide (TPDAP, and hybrid monomer 4-(N-phthalimidophenyl glycidylether (PPGE were synthesized and characterized by Fourier transform infrared (FTIR spectroscopy, nuclear magnetic resonance (NMR spectroscopy, and elemental analysis (EDX. PPGE was incorporated in bisphenol A epoxy resin (BPA in various concentrations (5% to 20%, based on a weight percentage of BPA resin. Curing was carried out with the stoichiometric amount of TPDAP and 1,3-propanediamine (PDA to result in cross-link network. Various mechanical, chemical, thermal, and flame retardant properties of modified and unmodified epoxy resin were studied. The coatings obtained with the addition of PPGE were found to have improved properties as compared with those of the unmodified resin. Coatings with 15% loading of PPGE showed improved flame retardant and mechanical properties with stable thermal behaviour.

  6. A probabilistic approach to rock mechanical property characterization for nuclear waste repository design

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kunsoo; Gao, Hang [Columbia Univ., New York, NY (United States)

    1996-04-01

    A probabilistic approach is proposed for the characterization of host rock mechanical properties at the Yucca Mountain site. This approach helps define the probability distribution of rock properties by utilizing extreme value statistics and Monte Carlo simulation. We analyze mechanical property data of tuff obtained by the NNWSI Project to assess the utility of the methodology. The analysis indicates that laboratory measured strength and deformation data of Calico Hills and Bullfrog tuffs follow an extremal. probability distribution (the third type asymptotic distribution of the smallest values). Monte Carlo simulation is carried out to estimate rock mass deformation moduli using a one-dimensional tuff model proposed by Zimmermann and Finley. We suggest that the results of these analyses be incorporated into the repository design.

  7. One-Dimensional Perovskite Manganite Oxide Nanostructures: Recent Developments in Synthesis, Characterization, Transport Properties, and Applications

    Science.gov (United States)

    Li, Lei; Liang, Lizhi; Wu, Heng; Zhu, Xinhua

    2016-03-01

    One-dimensional nanostructures, including nanowires, nanorods, nanotubes, nanofibers, and nanobelts, have promising applications in mesoscopic physics and nanoscale devices. In contrast to other nanostructures, one-dimensional nanostructures can provide unique advantages in investigating the size and dimensionality dependence of the materials' physical properties, such as electrical, thermal, and mechanical performances, and in constructing nanoscale electronic and optoelectronic devices. Among the one-dimensional nanostructures, one-dimensional perovskite manganite nanostructures have been received much attention due to their unusual electron transport and magnetic properties, which are indispensable for the applications in microelectronic, magnetic, and spintronic devices. In the past two decades, much effort has been made to synthesize and characterize one-dimensional perovskite manganite nanostructures in the forms of nanorods, nanowires, nanotubes, and nanobelts. Various physical and chemical deposition techniques and growth mechanisms are explored and developed to control the morphology, identical shape, uniform size, crystalline structure, defects, and homogenous stoichiometry of the one-dimensional perovskite manganite nanostructures. This article provides a comprehensive review of the state-of-the-art research activities that focus on the rational synthesis, structural characterization, fundamental properties, and unique applications of one-dimensional perovskite manganite nanostructures in nanotechnology. It begins with the rational synthesis of one-dimensional perovskite manganite nanostructures and then summarizes their structural characterizations. Fundamental physical properties of one-dimensional perovskite manganite nanostructures are also highlighted, and a range of unique applications in information storages, field-effect transistors, and spintronic devices are discussed. Finally, we conclude this review with some perspectives/outlook and future

  8. One-Dimensional Perovskite Manganite Oxide Nanostructures: Recent Developments in Synthesis, Characterization, Transport Properties, and Applications.

    Science.gov (United States)

    Li, Lei; Liang, Lizhi; Wu, Heng; Zhu, Xinhua

    2016-12-01

    One-dimensional nanostructures, including nanowires, nanorods, nanotubes, nanofibers, and nanobelts, have promising applications in mesoscopic physics and nanoscale devices. In contrast to other nanostructures, one-dimensional nanostructures can provide unique advantages in investigating the size and dimensionality dependence of the materials' physical properties, such as electrical, thermal, and mechanical performances, and in constructing nanoscale electronic and optoelectronic devices. Among the one-dimensional nanostructures, one-dimensional perovskite manganite nanostructures have been received much attention due to their unusual electron transport and magnetic properties, which are indispensable for the applications in microelectronic, magnetic, and spintronic devices. In the past two decades, much effort has been made to synthesize and characterize one-dimensional perovskite manganite nanostructures in the forms of nanorods, nanowires, nanotubes, and nanobelts. Various physical and chemical deposition techniques and growth mechanisms are explored and developed to control the morphology, identical shape, uniform size, crystalline structure, defects, and homogenous stoichiometry of the one-dimensional perovskite manganite nanostructures. This article provides a comprehensive review of the state-of-the-art research activities that focus on the rational synthesis, structural characterization, fundamental properties, and unique applications of one-dimensional perovskite manganite nanostructures in nanotechnology. It begins with the rational synthesis of one-dimensional perovskite manganite nanostructures and then summarizes their structural characterizations. Fundamental physical properties of one-dimensional perovskite manganite nanostructures are also highlighted, and a range of unique applications in information storages, field-effect transistors, and spintronic devices are discussed. Finally, we conclude this review with some perspectives/outlook and future

  9. Topological and metrical property characterization of radical subunits for ternary hard sphere crystals

    Science.gov (United States)

    Wang, Lin; An, Xizhong; Wang, Defeng; Qian, Quan

    2016-01-01

    Quantitative characterization on the topological and metrical properties of radical subunits (polyhedra) for two new ternary hard sphere crystals was studied. These two ideal crystalline structures are numerically constructed by filling small and medium spheres into interstices (corresponding to regular tetrahedral and octahedral pores) of perfect face centered cubic (FCC) and hexagonal close packed (HCP) crystals formed by the packing of large spheres. Topological properties such as face number, edge number, vertex number of each radical polyhedron (RP), edge number of each RP face and metrical properties such as volume, surface area, total perimeter and pore volume of each RP, area and perimeter of each RP face were analyzed and compared. The results show that even though the overall packing densities for FCC and HCP ternary crystals are the same, different characteristics of radical polyhedra for corresponding spheres in these two crystals can be identified. That is, in the former structure RPs are more symmetric than those in the latter; the orientations of corresponding RP in the latter are twice as many as that in the former. Moreover, RP topological and metrical properties in the HCP ternary crystal are much more complicated than those in the FCC ternary crystal. These differences imply the structure and property differences of these two ternary crystals. Analyses of RPs provide intensive understanding of pores in the structure.

  10. Topological and metrical property characterization of radical subunits for ternary hard sphere crystals

    Directory of Open Access Journals (Sweden)

    Lin Wang

    2016-01-01

    Full Text Available Quantitative characterization on the topological and metrical properties of radical subunits (polyhedra for two new ternary hard sphere crystals was studied. These two ideal crystalline structures are numerically constructed by filling small and medium spheres into interstices (corresponding to regular tetrahedral and octahedral pores of perfect face centered cubic (FCC and hexagonal close packed (HCP crystals formed by the packing of large spheres. Topological properties such as face number, edge number, vertex number of each radical polyhedron (RP, edge number of each RP face and metrical properties such as volume, surface area, total perimeter and pore volume of each RP, area and perimeter of each RP face were analyzed and compared. The results show that even though the overall packing densities for FCC and HCP ternary crystals are the same, different characteristics of radical polyhedra for corresponding spheres in these two crystals can be identified. That is, in the former structure RPs are more symmetric than those in the latter; the orientations of corresponding RP in the latter are twice as many as that in the former. Moreover, RP topological and metrical properties in the HCP ternary crystal are much more complicated than those in the FCC ternary crystal. These differences imply the structure and property differences of these two ternary crystals. Analyses of RPs provide intensive understanding of pores in the structure.

  11. Characterization of Skeletonema costatum Intracellular Organic Matter and Study of Nanomechanical Properties under Different Solution Conditions

    KAUST Repository

    Gutierrez, Leonardo

    2016-06-17

    In the current investigation, a rigorous characterization of the high molecular weight (HMW) compounds of Skeletonema costatum (SKC) intracellular organic matter (IOM), including nanomechanical properties, was conducted. HMW SKC-IOM was characterized as a mixture of polysaccharides, proteins, and lipids. Atomic force microscopy (AFM) provided crucial information of this isolate at a nanoscale resolution. HMW SKC-IOM showed highly responsive to solution chemistry: fully extended chains at low ionic strength, and compressing structures with increasing electrolyte concentration in solution. Interestingly, two regions of different nanomechanical properties were observed: (a) Region #1: located farther from the substrate and showing extended polymeric chains, and (b) Region #2: located <10 nm above the substrate and presenting compressed structures. The polymer length, polymer grafting density, and compressibility of these two regions were highly influenced by solution conditions. Results suggest that steric interactions originating from HMW SKC-IOM polymeric structure would be a dominant interacting mechanism with surfaces. The current investigation has successfully applied models of polymer physics to describe the complex HMW SKC-IOM structural conformation at different solution conditions. The detailed methodology presented provides a tool to characterize and understand biopolymers interactions with surfaces, including filtration membranes, and can be extended to other environmentally relevant organic compounds.

  12. Characterization of Local Mechanical Properties of Polymer Thin Films and Polymer Nanocomposites via AFM indentations

    Science.gov (United States)

    Cheng, Xu

    AFM indentation has become a tool with great potential in the characterization of nano-mechanical properties of materials. Thanks to the nanometer sized probes, AFM indentation is capable of capturing the changes of multiple properties within the range of tens of nanometers, such task would otherwise be difficult by using other experiment instruments. Despite the great potentials of AFM indentation, it operates based on a simple mechanism: driving the delicate AFM probe to indent the sample surface, and recording the force-displacement response. With limited information provided by AFM indentation, efforts are still required for any practice to successfully extract the desired nano-scale properties from specific materials. In this thesis, we focus on the mechanical properties of interphase between polymer and inorganic materials. It is known that in nanocomposites, a region of polymer exist around nanoparticles with altered molecular structures and improved properties, which is named as interphase polymer. The system with polymer thin films and inorganic material substrates is widely used to simulate the interphase effect in nanocomposites. In this thesis, we developed an efficient and reliable method to process film/substrate samples and characterize the changes of local mechanical properties inside the interphase region with ultra-high resolution AFM mechanical mapping technique. Applying this newly developed method, the interphase of several film/substrate pairs were examined and compared. The local mechanical properties on the other side of the polymer thin film, the free surface side, was also investigated using AFM indentation equipped with surface modified probes. In order to extract the full spectrum of local elastic modulus inside the surface region in the range of only tens of nanometers, the different contact mechanics models were studied and compared, and a Finite Element model was also established. Though the film/substrate system has been wide used as

  13. Characterization-Based Molecular Design of Biofuel Additives Using Chemometric and Property Clustering Techniques

    Directory of Open Access Journals (Sweden)

    Subin eHada

    2014-06-01

    Full Text Available In this work, multivariate characterization data such as infrared (IR spectroscopy was used as a source of descriptor data involving information on molecular architecture for designing structured molecules with tailored properties. Application of multivariate statistical techniques such as principal component analysis (PCA allowed capturing important features of the molecular architecture from complex data to build appropriate latent variable models. Combining the property clustering techniques and group contribution methods (GCM based on characterization data in a reverse problem formulation enabled identifying candidate components by combining or mixing molecular fragments until the resulting properties match the targets. The developed methodology is demonstrated using molecular design of biodiesel additive which when mixed with off-spec biodiesel produces biodiesel that meets the desired fuel specifications. The contribution of this work is that the complex structures and orientations of the molecule can be included in the design, thereby allowing enumeration of all feasible candidate molecules that matched the identified target but were not part of original training set of molecules.

  14. Fabrication, Characterization, Properties, and Applications of Low-Dimensional BiFeO3 Nanostructures

    Directory of Open Access Journals (Sweden)

    Heng Wu

    2014-01-01

    Full Text Available Low-dimensional BiFeO3 nanostructures (e.g., nanocrystals, nanowires, nanotubes, and nanoislands have received considerable attention due to their novel size-dependent properties and outstanding multiferroic properties at room temperature. In recent years, much progress has been made both in fabrications and (microstructural, electrical, and magnetic in characterizations of BiFeO3 low-dimensional nanostructures. An overview of the state of art in BiFeO3 low-dimensional nanostructures is presented. First, we review the fabrications of high-quality BiFeO3 low-dimensional nanostructures via a variety of techniques, and then the structural characterizations and physical properties of the BiFeO3 low-dimensional nanostructures are summarized. Their potential applications in the next-generation magnetoelectric random access memories and photovoltaic devices are also discussed. Finally, we conclude this review by providing our perspectives to the future researches of BiFeO3 low-dimensional nanostructures and some key problems are also outlined.

  15. V2O5 xerogel-poly(ethylene oxide) hybrid material: Synthesis, characterization, and electrochemical properties

    International Nuclear Information System (INIS)

    In this work, we report the synthesis, characterization, and electrochemical properties of vanadium pentoxide xerogel-poly(ethylene oxide) (PEO) hybrid materials obtained by varying the average molecular weight of the organic component as well as the components' ratios. The materials were characterized by X-ray diffraction, ultraviolet/visible and infrared spectroscopies, thermogravimetric analysis, scanning electron microscopy, electron paramagnetic resonance, and cyclic voltammetry. Despite the presence of broad and low intensity peaks, the X-ray diffractograms indicate that the lamellar structure of the vanadium pentoxide xerogel is preserved, with increase in the interplanar spacing, giving evidence of a low-crystalline structure. We found that the electrochemical behaviour of the hybrid materials is quite similar to that found for the V2O5 xerogel alone, and we verified that PEO leads to stabilization and reproducibility of the Li+ electrochemical insertion/de-insertion into the V2O5 xerogel structure, which makes these materials potential components of lithium ion batteries. - Graphical abstract: The synthesis, structural and electrochemical properties of vanadium pentoxide xerogel-poly(ethylene oxide) hybrid materials have been described. Despite the presence of broad and low intensity peaks, the X-ray diffractograms indicate that the lamellar structure of the vanadium pentoxide xerogel is preserved. The cyclic voltammetry technique demonstrated that PEO intercalation provides an improvement in the electrochemical properties, mainly with respect to the lithium electroinsertion process into the oxide matrix

  16. Characterization and property evaluation of U-15 wt%Pu alloy for fast reactor

    Science.gov (United States)

    Kaity, Santu; Banerjee, Joydipta; Ravi, K.; Keswani, R.; Kutty, T. R. G.; Kumar, Arun; Prasad, G. J.

    2013-02-01

    The characterization and high temperature behaviour of U-15 wt%Pu alloy has been investigated in this study for the first time. U-15 wt%Pu alloy sample for this study was prepared by following melting and casting route. Microstructural characterization of the alloy was carried out by XRD and optical microscopy. The thermophysical properties like phase transition temperatures, coefficient of thermal expansion and hot hardness of the above alloy were determined. Eutectic temperature between T91 and U-15 wt%Pu was established. Apart from that, the fuel-cladding chemical compatibility of U-15 wt%Pu alloy with T91 grade steel was studied by diffusion couple experiment.

  17. AFM characterization and electrochemical property of Ag nanowires by modified AAO template method

    International Nuclear Information System (INIS)

    Ag nanowires as electrode materials were prepared from modified anodic aluminum oxide (AAO) template method by using dextrose as reductive, and the process of Ag nanowires growth was monitored by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The structure and electrochemical properties of Ag nanowires were characterized by X-ray diffraction (XRD), UV-vis absorption spectra and cyclic voltammograms (CV) measurements. The results show that Ag nanowires prepared from AAO possessed typical face centered cubic structure with average diameter of 60 nm. Furthermore, the CV characterization reveals that Ag nanowires featured a pair of asymmetrical redox peaks with the position near 0.5 V and the microstructure was maintained in electrochemical reaction

  18. Microstructural characterization and properties of dissimilar joints used in coupling of PWR control rod driving

    International Nuclear Information System (INIS)

    The chemical, mechanical and microstructural characterizations of a dissimilar joint between SA336F347 austenitic and SA479Tp414 martensitic stainless steels were done, welded by TIG process, defining as a result of this characterization that the ER Ni Cr-3 Ni consumable seems to be the best applicable consumable compared to the ER309L consumable; The main variables of the process control were also evaluated, its weldability and properties for a future qualification of a welding procedure, besides to simulate possible situations to be found in this type of joint, such as, its weldability by the LASER process, welded joint without filler metal and without shielding gas, obtaining in this way enough data for the production of products that contains this type of joint. (author)

  19. Characterizing Economic and Social Properties of Trust and Reputation Systems in P2P Environment

    Institute of Scientific and Technical Information of China (English)

    Yu-Feng Wang; Yoshiaki Hori; Kouichi Sakurai

    2008-01-01

    Considering the fact that P2P (Peer-to-Peer) systems are self-organized and autonomous, social-control mechanism (like trust and reputation) is essential to evaluate the trustworthiness of participating peers and to combat the selfish, dishonest and malicious peer behaviors. So, naturally, we advocate that P2P systems that gradually act as an important information infrastructure should be multi-disciplinary research topic, and reflect certain features of our society. So, from economic and social perspective, this paper designs the incentive-compatible reputation feedback scheme based on well-known economic model, and characterizes the social features of trust network in terms of efficiency and cost. Specifically, our framework has two distinctive purposes: first, from high-level perspective, we argue trust system is a special kind of social network, and an accurate characterization of the structural properties of the network can be of fundamental importance to understand the dynamics of the system. Thus, inspired by the concept of weighted small-world, this paper proposes new measurements to characterize the social properties of trust system, that is, highg lobal and local efficiency, and low cost; then, from relative low-level perspective, we argue that reputation feedback is a special kind of information, and it is not free. So, based on economic model, VCG (Vickrey-Clarke-Grove)-like reputation remuneration mechanism is proposed to stimulate rational peers not only to provide reputation feedback, but truthfully offer feedback. Furthermore, considering that trust and reputation is subjective, we classify the trust into functional trust and referral trust, and extend the referral trust to include two factors: similarity and truthfulness, which can efficiently reduce the trust inference error. The preliminary simulation results show the benefits of our proposal and the emergence of certain social properties in trust network.

  20. Invertase immobilized on macroporous p,lystyrene: properties and kinetic characterization

    Energy Technology Data Exchange (ETDEWEB)

    Mansfeld, J.; Schellenberger, A.

    1987-01-01

    Invertase from baker's yeast (Saccharomyces cerevisiae) was covalently bound via benzoquinone and glutaraldehyde to a macroporous polystyrene anion exchanger. The behavior of the invertase-polystyrene complexes in batch and packed-bed reactors was characterized kinetically. In addition to kinetic studies on sucrose hydrolysis at low initial substrate concentrations, the dependence of conversion degree on flow rate at high, industrially used substrate concentrations was determined. The described invertase-polystyrene complexes are suitable for technical application in the production of glucose-fructose mixtures because of their high specific and relative activities, as well as the good hydrodynamical and mechanical properties of the polystyrene matrix. 25 references.

  1. CdTe Quantum Dots Embedded in Multidentate Biopolymer Based on Salep: Characterization and Optical Properties

    OpenAIRE

    Ghasem Rezanejade Bardajee; Zari Hooshyar

    2013-01-01

    This paper describes a novel method for surface modification of water soluble CdTe quantum dots (QDs) by using poly(acrylic acid) grafted onto salep (salep-g-PAA) as a biopolymer. As-prepared CdTe-salep-g-PAA QDs were characterized by Fourier transform infrared (FT-IR) spectrum, thermogravimetric (TG) analysis, and transmission electron microscopy (TEM). The absorption and fluorescence emission spectra were measured to investigate the effect of salep-g-PAA biopolymer on the optical propertie...

  2. Characterization of Physical, Thermal and Spectral Properties of Biofield Treated 2,6-Dichlorophenol

    OpenAIRE

    Trivedi, Mahendra Kumar

    2015-01-01

    2,6-Dichlorophenol (2,6-DCP) is a compound used for the synthesis of chemicals and pharmaceutical agents. The present work is intended to evaluate the impact of Mr. Trivedi’s biofield energy treatment on physical, thermal and spectral properties of the 2,6-DCP. The control and treated 2,6-DCP were characterized by various analytical techniques such as X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) sp...

  3. Synthesis, characterization and catalytic properties of CuO nanocrystals with various shapes

    International Nuclear Information System (INIS)

    CuO nanocrystals with different shapes, i.e. irregular nanoparticles, nanobelts and nanoplatelets, have been synthesized by controlling a few critical synthesis parameters to explore their catalytic properties. It was found that the rate of CO oxidation on the nanoplatelets is over six times higher than that on the nanoparticles and about three times higher than that on the nanobelts at 110 deg. C. Based on combined characterizations, such as BET, XRD, TEM, HRTEM and CO temperature-programmed reduction, the relationship between the catalytic reactivity and the shape as well as the predominantly exposed crystal planes of the CuO nanocrystals has been discussed

  4. Zinc oxide nanoparticle-coated films: fabrication, characterization, and antibacterial properties

    OpenAIRE

    Jiang, Y.(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China; Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui, China; Department of Physics, Nanjing University, Nanjing, Jiangsu, China; School of Physics, Shandong University, Jinan, Shandong, China; Physics Department, Shanghai Jiao Tong University, Shanghai, China); O'Neill, AJ; Ding, Y.

    2015-01-01

    In this article, novel antibacterial PVC-based films coated with ZnO nanoparticles (NPs) were fabricated, characterized, and studied for their antibacterial properties. It was shown that the ZnO NPs were coated on the surface of the PVC films uniformly and that the coating process did not affect the size and shape of the NPs on the surface of PVC films. Films coated with concentrations of either 0.2 or 0.075 g/L of ZnO NPs exhibited antibacterial activity against both Gram-positive (Staphyloc...

  5. The WO3/WS2 nanostructures: Preparation, characterization and optical absorption properties

    Science.gov (United States)

    Cao, Shixiu; Zhao, Cong; Han, Tao; Peng, Lingling

    2016-07-01

    The WO3/WS2 nanostructures were successfully prepared using a two-step hydrothermal/gas phase method. The physical properties of the nanostructures were characterized using XRD, SEM, TEM, UV-visible spectroscopy. The WO3/WS2 nanostructures obtained were coexistence of WO3 and WS2 in the same particle. The WO3/WS2 nanostructures contained a wide and intensive absorption in the UV-visible light region of 245-750 nm, which showed that the WO3/WS2 nanostructures may have a potential application as an UV-visible photocatalyst.

  6. Laboratory Characterization of Chemico-osmotic, Hydraulic and Diffusion Properties of Rocks: Apparatus Development

    International Nuclear Information System (INIS)

    Excess fluid pressures induced by chemical osmosis in natural formations may have a significant influence on groundwater systems in a geological time scale. Examinations of the possibility and duration times require characterization of the chemico-osmotic, hydraulic and diffusion properties of representative formation media under field conditions. To develop a laboratory apparatus for chemical osmosis experiments that simulates in-situ conditions, typical litho-static and background pore pressures, a fundamental concept of the chemical osmosis experiment using a closed fluid circuit system (referred to as a closed system hereafter) was revisited. Coupled processes in the experiment were examined numerically. In preliminary experiments at atmospheric pressure a chemical osmosis experiment using the closed system was demonstrated. An approximation method for determining the chemico-osmotic property was attempted. Based on preliminary examinations, an experimental system capable of loading the confining and pore pressures on the sample was thus developed. (authors)

  7. Barium hexaferrite/graphene oxide: controlled synthesis and characterization and investigation of its magnetic properties

    Science.gov (United States)

    Maddahfar, Mahnaz; Ramezani, Majid; Mostafa Hosseinpour-Mashkani, S.

    2016-08-01

    In the present study, barium hexaferrite nanocrystals (BaFe12O19) were successfully synthesized through the two-step sol-gel method in an aqueous solution in the presence of barium nitrate and iron (III) nitrate. Besides, the effect of the molar ratio of graphene oxide on the particle size and magnetic properties of final product was investigated. In this research, glucose plays a role as capping and chelating agent in the synthesis of BaFe12O19/graphene oxide. Moreover, it was found that the size, morphology, and magnetic properties of the final products could be greatly influenced by the molar ratio of graphene oxide. BaFe12O19/graphene oxide was characterized by using X-ray diffraction, scanning electron microscope, Fourier transform infrared spectroscopy, vibrating sample magnetometer, and energy-dispersive spectrometry.

  8. Synthesis, Characterization, Electrical Conductivity and Fluorescence Properties of Polyimine Bearing Phenylacetylene Units.

    Science.gov (United States)

    Şenol, Dilek; Kolcu, Feyza; Kaya, İsmet

    2016-09-01

    In this study, a Schiff base was synthesized by the condensation reaction of 4-bromobenzaldehyde and 4-aminophenol. Then, phenylacetylene substituted Schiff base monomer (IPA) was obtained by HBr elimination reaction of IPA with phenylacetylene through Sonogashira reaction. IPA was polymerized via chemical oxidative polycondensation reaction. FT-IR and NMR measurements were used for the structural analyses of the synthesized substances. Fluorescence and UV-Vis analyses were carried out for optical characterization. Electrochemical characteristics, electrical conductivities and thermal properties were determined using cyclic voltammetry (CV), four-point probe conductometer, TG-DTA and DSC methods. The main purpose of the present study was to investigate the effects of phenylacetylene bearing units on the properties of conjugated aromatic polyimines. The spectral analysis signified a green light emission behavior when irradiated at different wavelengths. Combined with fluorescent behavior and good thermal stability, the electrical conductivity was found to be very crucial for π-conjugated polymer. PMID:27338948

  9. A simple method to characterize the electrical and mechanical properties of micro-fibers

    CERN Document Server

    Castellanos-Gomez, Andres

    2013-01-01

    A procedure to characterize the electrical and mechanical properties of micro-fibers is presented here. As the required equipment can be found in many teaching laboratories, it can be carried out by physics and mechanical/electrical engineering students. The electrical resistivity, mass density and Young's modulus of carbon micro-fibers have been determined using this procedure, obtaining values in very good agreement with the reference values. The Young's modulus has been obtained by measuring the resonance frequency of carbon fiber based cantilevers. In this way, one can avoid common approaches based on tensile or bending tests which are difficult to implement for microscale materials. Despite the simplicity of the experiments proposed here, they can be used to trigger in the students interest on the electrical and mechanical properties of microscale materials.

  10. Characterization of Microstructure and Mechanical Properties of Resistance Spot Welded DP600 Steel

    Directory of Open Access Journals (Sweden)

    Ali Ramazani

    2015-09-01

    Full Text Available Resistance spot welding (RSW as a predominant welding technique used for joining steels in automotive applications needs to be studied carefully in order to improve the mechanical properties of the spot welds. The objectives of the present work are to characterize the resistance spot weldment of DP600 sheet steels. The mechanical properties of the welded joints were evaluated using tensile-shear and cross-tensile tests. The time-temperature evolution during the welding cycle was measured. The microstructures observed in different sites of the welds were correlated to thermal history recorded by thermocouples in the corresponding areas. It was found that cracks initiated in the periphery region of weld nuggets with a martensitic microstructure and a pull-out failure mode was observed. It was also concluded that tempering during RSW was the main reason for hardness decrease in HAZ.

  11. Magnetic refrigeration cycle analysis using selected thermodynamic property characterizations for gadolinium gallium garnet

    International Nuclear Information System (INIS)

    Magneto-thermodynamic property characterizations were selected, adapted, and compared to material property data for gadolinium gallium garnet in the temperature range 4--40 K and magnetic field range 0--6 T. The most appropriate formulations were incorporated into a model in which methods similar to those previously developed for other materials and temperature ranges were used to make limitation and relative performance assessments of Carnot, ideal regenerative, and pseudo-constant field regenerative cycles. Analysis showed that although Carnot cycle limitations on available temperature lift for gadolinium gallium garnet are not as severe as those for materials previously examined, substantial improvements in cooling capacity/temperature lift combinations can be achieved using regenerative cycles within specified fields limits if significant loss mechanisms are mitigated

  12. Synthesis, characterization and luminescent properties of Tb(III) doped Eu(III) complex nanoparticles

    International Nuclear Information System (INIS)

    In recent years, considerable effort has been devoted to the development of transition metal complexes as novel luminescent materials that have potential application in the fluorescent labels for chemistry or biology. Among them, the nanostructured lanthanide complexes have been receiving much attention because of their excellent luminescence properties, which are attributed to the intramolecular energy transfer between the ligands and chelated lanthanide ions and their high solubility in water. This paper presents some results of the synthesis and characterization of the nanoparticles of Eu(III) and Tb(III) complexes with naphthoyl trifluoroacetone and tri-n-octylphosphineoxide. In addition, the influence of the dopant Tb(III) on the photophysical properties of the system of lanthanide complexes of Eu(III) and Tb(III) is also studied

  13. Polythiophenes based on pyrene as pendant group: Synthesis, structural characterization and luminescent properties

    Science.gov (United States)

    González-Juárez, E.; Güizado-Rodríguez, M.; Barba, V.; Melgoza-Ramírez, M.; Rodríguez, M.; Ramos-Ortíz, G.; Maldonado, J. L.

    2016-01-01

    Novel polythiophenes (PTs) derived from 3-alkylthiophenes (R = hexyl, octyl) and a thiophene functionalized with pyrene chromophore were synthesized. A homopolymer and copolymers were obtained by using different stoichiometric ratios, and their photophysical properties were investigated. Physicochemically characterized by FT-IR, 1H NMR, UV-vis, DSC-TGA and GPC as well as fluorescence spectroscopy, the new PTs reached moderate molecular weight distributions, exhibited good thermal properties and were easily processable for depositing films of satisfactory optical quality with third-order nonlinear optical susceptibilities of approximately 10-12 esu. The new PTs showed absorption and emission bands ranging from 346 to 430 nm, and from 450 to 570 nm, respectively, with quantum yields between 0.07 and 0.25. In addition, nanoparticles were obtained from the PTs by using the mini-emulsion technique. Their spectroscopic characteristics and morphology were determined by means of UV-vis spectroscopy and SEM analysis.

  14. Characterization of the mechanical properties of HL-1 cardiomyocytes with high throughput magnetic tweezers

    International Nuclear Information System (INIS)

    We characterized the mechanical properties of cardiomyocyte-like HL-1 cells using our recently developed multi-pole magnetic tweezers. With the optimized design, both high force and high throughput are achieved at the same time. Force up to 100 pN can be applied on a 1 μm diameter superparamagnetic bead in a workspace with 60 μm radius, which is encircled symmetrically by 3 sharp magnetic tips. By adjusting the coil currents, both the strength and direction of force can be controlled. The result shows that both viscosity and shear elastic modulus of HL-1 cells exhibit an approximately log-normal distribution. The cells became stiffer as they matured, consistent with a transition from proliferating cells to contractile muscle tissue. Moreover, the mechanical properties of HL-1 cells show high heterogeneity, which agrees well with their physiological structure

  15. Structural characterization and properties of konjac glucomannan/curdlan blend films.

    Science.gov (United States)

    Wu, Chunhua; Peng, Shuhui; Wen, Chengrong; Wang, Xiumei; Fan, Linlin; Deng, Ronghua; Pang, Jie

    2012-06-20

    A series of novel edible blend films of konjac glucomannan (KGM) and curdlan were prepared by a solvent-casting technique with different blending ratios of the two polymers. The Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), etc. were used to characterize the change of structure and properties of blend films. The results showed that the strong intermolecular hydrogen bonds took place between KGM and curdlan. And the interaction of the blend film was much greater than that of the others when the KGM content in the blend films was around 70 wt% (KC7), resulting in excellent miscibility. The conclusion of the electron tensile testing analysis indicated that the blend film KC7 showed the maximum tensile strength (42.93±1.92 MPa). In addition, the blend films displayed excellent moisture barrier properties, which had a potential application in the food field. PMID:24750750

  16. CdTe Quantum Dots Embedded in Multidentate Biopolymer Based on Salep: Characterization and Optical Properties

    Directory of Open Access Journals (Sweden)

    Ghasem Rezanejade Bardajee

    2013-01-01

    Full Text Available This paper describes a novel method for surface modification of water soluble CdTe quantum dots (QDs by using poly(acrylic acid grafted onto salep (salep-g-PAA as a biopolymer. As-prepared CdTe-salep-g-PAA QDs were characterized by Fourier transform infrared (FT-IR spectrum, thermogravimetric (TG analysis, and transmission electron microscopy (TEM. The absorption and fluorescence emission spectra were measured to investigate the effect of salep-g-PAA biopolymer on the optical properties of CdTe QDs. The results showed that the optical properties of CdTe QDs were significantly enhanced by using salep-g-PAA-based biopolymer.

  17. Quantitative characterization of the microstructure and properties of nanocrystalline WC–Co bulk

    International Nuclear Information System (INIS)

    Graphical abstract: Microstructure of the nanocrystalline WC–Co cermet bulk was quantitatively described by transmission electron microscopy based precession electron diffraction technology. It is discovered that the fraction of the Σ2 grain boundaries increases with the decrease of WC grain size. The effect of microstructure on mechanical properties depends on Co distribution, Σ2 boundaries fraction and WC grain contiguity. -- Nanocrystalline WC–Co bulk was prepared using a novel route that combined in situ reactions and subsequent spark plasma sintering. The microstructure was characterized by transmission electron microscopy-based precession electron diffraction technology. The nanocrystalline microstructure has a high WC grain contiguity. The fraction of Σ2 boundaries increases with a decrease in WC grain size. The effect of microstructure on the mechanical properties was analyzed in terms of the correlations between Co distribution, Σ2 boundary fraction and WC grain contiguity.

  18. Physicochemical characterization and dissolution properties of nimesulide-cyclodextrin binary systems.

    Science.gov (United States)

    Nalluri, Buchi N; Chowdary, K P R; Murthy, K V R; Hayman, A R; Becket, G

    2003-01-01

    The objective of this work is physicochemical characterization of nimesulide-cyclodextrin binary systems both in solution and solid state and to improve the dissolution properties of nimesulide (N) via complexation with alpha-, beta, and gamma-cyclodextrins (CDs). Detection of inclusion complexation was done in solution by means of phase solubility analysis, mass spectrometry, and 1H nuclear magnetic resonance (1H-NMR) spectroscopic studies, and in solid state using differential scanning calorimetry (DSC), powder x-ray diffractometry (X-RD), scanning electron microscopy (SEM), and in vitro dissolution studies. Phase solubility, mass spectrometry and 1H-NMR studies in solution revealed 1:1 M complexation of N with all CDs. A true inclusion of N with beta-CD at 1:2 M in solid state was confirmed by DSC, powder X-RD and SEM studies. Dissolution properties of N-CD binary systems were superior when compared to pure N. PMID:12916912

  19. Physicochemical characterization and dissolution properties of meloxicam-cyclodextrin binary systems.

    Science.gov (United States)

    Naidu, N Buchi; Chowdary, K P R; Murthy, K V R; Satyanarayana, V; Hayman, A R; Becket, G

    2004-04-01

    The objective of the work is physicochemical characterization of meloxicam (ME)-cyclodextrin (CD) binary systems both in solution and solid states and to improve the dissolution properties of meloxicam via complexation with alpha-, beta- and gamma-cyclodextrins. Detection of inclusion complexation was done in solution state by means of phase solubility analysis, mass spectrometry and 1H nuclear magnetic resonance (NMR) studies, and in solid state using differential scanning calorimetry (DSC), powder X-ray diffractometry, and in vitro dissolution studies. Phase solubility, mass spectrometry and 1H NMR studies in solution state revealed 1:1M complexation of meloxicam with all CDs. A true inclusion of ME with gamma-CD at 1:1 and 1:2M in solid state was confirmed by DSC, powder XRD and scanning electron microscopy (SEM) studies. Dissolution properties of ME-CDs binary systems were superior when compared to pure ME. PMID:15030882

  20. A comparative study of constant-order and variable-order fractional models in characterizing memory property of systems

    Science.gov (United States)

    Sun, H. G.; Chen, W.; Wei, H.; Chen, Y. Q.

    2011-03-01

    How to characterize the memory property of systems is a challenging issue in the modeling and analysis of complex systems. This study makes a comparative investigation of integer-order derivative, constant-order fractional derivative and two types of variable-order fractional derivatives in characterizing the memory property of systems. The advantages and potential applications of two variable-order derivative definitions are highlighted through a comparative analysis of anomalous relaxation process.

  1. Characterizing petrophysical properties of carbonate rocks using nuclear magnetic resonance and spectral induced polarization

    Science.gov (United States)

    Zhang, Fan; Zhang, Chi; Rankey, Eugene

    2016-04-01

    Unlike sandstones, with well-characterized correlations between porosity and permeability, carbonate rocks are well known for their highly complex petrophysical behaviors due to their intrinsically heterogeneous pore shape, pore size, and pore distributions and connectivity. The characterization of petrophysical properties of carbonate rocks, including rock properties and rock-fluid interactions, remains big challenges. This laboratory study focuses on integrating two geophysical methods: nuclear magnetic resonance (NMR) and spectral induced polarization (SIP) to determine porosity, pore size distribution, and permeability of carbonate rocks. NMR measures the relaxation of hydrogen nuclei at pore scale. Samples with different pore structures saturated by fluids have molecular relaxation responses to the external magnetic field which could generate various NMR signals. Permeability estimation from NMR in siliciclastic rocks is routine, however, is problematic in carbonates. SIP determines complex resistivity of a sample across a wide range of frequency and is sensitive to variations in the properties of solid-fluid and fluid-fluid interfaces in porous media. Previous studies investigated the relationships between permeability and parameters derived from SIP data, but are restricted to narrow lithology range. Our study used carbonate core samples from three depositional environments: tidal zone, shallow marine, and platform/reef margin of an atoll. Samples were fully saturated by water for T2 relaxation measurements and complex conductivity measurements at low frequencies. We compare the pore volume to surface area ratio measured from NMR and SIP and assess the applicability of established petrophysical models to estimate permeability from NMR and SIP data. We hope to build a relationship between NMR signals, SIP responses and petrophysical properties in carbonate rocks. The results could also provide new data and help further understand the unique and complex pore

  2. Characterization of sorption properties of selected soils from Lublin region by using water vapour adsorption method

    Science.gov (United States)

    Skic, Kamil; Boguta, Patrycja; Sokołowska, Zofia

    2016-04-01

    *The studies were carried out within the framework of a research project. The project was financed from funds of National Science Center on the base of decision number DEC-2013/11/D/NZ9/02545 Among many methods proposed to study sorption properties of soils an analysis of adsorption/ desorption isotherm is probably the easiest and most convenient one. It characterizes both quantity and quality of mineral and organic components and also their physical and physicochemical properties. The main aim of this study is comparison of sorption properties of selected Polish soils by using water vapour adsorption method. Samples were taken from the depth of 0-20 cm, from the Lublin region, eastern Poland. Soils were selected on the basis of their different physicochemical properties and were classified as: Haplic Fluvisol, Haplic Chernozem, Mollic Gleysol, Rendzic Phaeozem, Stagnic Luvisol, Haplic Cambisol (WG WRB 2006). Data taken from experimental adsorption isotherms were used to determine parameters of monolayer capacity, specific surface area and the total amount of vapour adsorbed at relative pressure of 0.974. Obtained adsorption and desorption isotherms reviled that adsorbate molecules interacted with the soil particles in different extent. Similar monolayer capacity was observed for Haplic Fluvisol, Haplic Chernozem and Stagnic Luvisol, while for Mollic Gleysol was more than 4 times higher. Mollic Gleysol was also characterized by highest values of specific surface area as well as quantity of adsorbed vapour at relative pressure of 0.974. Higher sorption was caused by presence of soil colloids which contains functional groups of a polar nature (mainly hydroxyls, phenolic and carboxyls). These groups similarly to silicates, oxides, hydratable cations as well as electric charge form adsorption centres for water vapour molecules.

  3. Synthesis, characterization and magnetic properties of monodisperse Ni, Zn-ferrite nanocrystals

    International Nuclear Information System (INIS)

    Synthesization of monodisperse Ni, Zn-ferrite (Ni1−xZnxFe2O4, x=1, 0.8, 0.6, 0.5, 0.4, 0.2, 0.0) nanocrystals has been achieved by the inverse microemulsion method using CTAB as surfactant and kerosene as an oil phase. The detailed characterization of the synthesized nanocrystals and measurement of the magnetic properties has been done by techniques like X-ray diffraction (XRD), field emission transmission electron microscopy (FETEM), Fourier transform infrared spectroscopy (FITR) and Vibrating Sample Magnetometer (VSM) respectively. The relationship between the structure and composition of the nanocrystals with magnetic properties has been investigated. The nanocrystals size is found to be in the range 1–5 nm. The effect of Zn substitution on size and magnetic properties has been studied. It has been observed that magnetism changed from ferromagnetic at X= 0 to super paramagnetic to paramagnetic at X=1 as Zn concentration increased. The Curie temperature is found to decrease with an increase in Zn concentration. - Highlights: • Reverse microemulsion route is very facile route for synthesis of Ni1−xZnxFe2O4 ferrite. • Presence of Zn changes the structural and magnetic properties of the Zn substituted NiFe2O4. • The lattice constant increases with the increase in Zn substitution. • The curie temperature decreases with Zn concentration appreciably. • Magnetic behavior varies from ferromagnetic at x=0 to superparamagnetic to paramagnetic at x=1

  4. Graphene oxide-modified ZnO particles: synthesis, characterization, and antibacterial properties

    Directory of Open Access Journals (Sweden)

    Zhong LL

    2015-08-01

    Full Text Available Linlin Zhong, Kyusik Yun Department of Bionanotechnology, Gachon University, Gyeonggi-do, Republic of Korea Abstract: Nanosized ZnO particles with diameters of 15 nm were prepared with a solution precipitation method at low cost and high yield. The synthesis of the particles was functionalized by the organic solvent dimethylformamide, and the particles were covalently bonded to the surface of graphene oxide. The morphology of the graphene oxide sheets and ZnO particles was confirmed with field emission scanning electron microscopy and biological atomic force microscopy. Fourier transform infrared spectroscopy and X-ray diffraction were used to analyze the physical and chemical properties of the ZnO/graphene oxide composites that differed from those of the individual components. Enhanced electrochemical properties were detected with cyclic voltammetry, with a redox peak of the composites at 0.025 mV. Excellent antibacterial activity of ZnO/graphene oxide composites was observed with a microdilution method in which minimum inhibitory concentrations of 6.25 µg/mL for Escherichia coli and Salmonella typhimurium, 12.5 µg/mL for Bacillus subtilis, and 25 µg/mL for Enterococcus faecalis. After further study of the antibacterial mechanism, we concluded that a vast number of reactive oxygen species formed on the surface of composites, improving antibacterial properties. Keywords: graphene oxide, ZnO, characterization, antibacterial property

  5. Production, characterization, and mechanical properties of starch modified by Ophiostoma spp.

    Directory of Open Access Journals (Sweden)

    Saville, B. A.

    2006-11-01

    Full Text Available Microbial modification of starch with Ophiostoma spp. was investigated, with the purpose of developing a novel packaging material for the food or pharmaceutical industries. Various starch sources, such as tapioca, potato, corn, rice and amylopectin were tested as raw materials. The initial screening demonstrated that tapioca and potato starch had better performance for biopolymer production. The yield was about 85%. Preliminary characterization of the modified biopolymer was also conducted. Following microbial conversion, the percentage of molecules with molecular weight (abbreviated Mw more than 10M (abbreviations of million Daltons increased from 25% to 89% after 3 days, confirming that the modification increased the weight of the starch polymer. Fourier Transform Infrared (FT-IR revealed changes in the chemical structure of the starch after the modification. Both pure starches and the modified biopolymers were cast into films and tested for mechanical properties. The tensile tests showed that after treatment with the fungus, the peak stress and modulus of the films increased about 10 and 40 times, respectively. Also, the water barrier property was improved. Therefore, microbial modification positively impacted proper-ties relevant to the proposed application. Although the role of the fungus in the modification and the function-property relationship of the biopolymer are not yet completely clear, the results of this study show promise for development of a novel biopolymer that competes with existing packaging materials.

  6. DOE capabilities for in-situ characterization and monitoring of formation properties in the vadose zone

    International Nuclear Information System (INIS)

    The DOE Environmental Restoration (ER) Program faces the difficult task of characterizing the properties of the subsurface and identifying and mapping a large number of contaminants at landfills, surface disposal areas, spill sites, nuclear waste tanks, and subsurface contaminant plumes throughout the complex of DOE facilities. Geophysical borehole logs can measure formation properties such as bulk density, water content, and lithology, and can quantitatively analyze for radionuclides and such elements as chlorine and heavy metals. Since these measurements can be replaced as desired, they can be used for both initial characterization and monitoring of changes in contaminant concentration and water content (sometimes linked to contaminant migration), at a fraction of the cost of conventional sampling. The techniques develop at several DOE laboratories, and the experience that the authors have gained in making in-situ measurements in the vadose zone, are applicable to problems at many other DOE sites. Moreover, they can capitalize on existing inventories of boreholes. By building on this experience workers involved in ER projects at those sites should be able to obtain high-quality data at substantial reductions in cost and time

  7. Formulation development and characterization of cellulose acetate nitrate based propellants for improved insensitive munitions properties

    Institute of Scientific and Technical Information of China (English)

    Thelma MANNING; Keith LUHMANN; Steve VELARDE; Christine KNOTT; Stephanie M.PIRAINO; Kevin BOYD; Jeffrey WYCKOFF; Carlton ADAM; Eugene ROZUMOV; Kenneth KLINGAMAN; Viral PANCHAL; Joseph LAQUIDARA; Mike FAIR; John BOLOGNINI

    2014-01-01

    Cellulose acetate nitrate (CAN) was used as an insensitive energetic binder to improve the insensitive munitions (IM) properties of gun propellants to replace the M1 propellant used in 105 mm artillery charges. CAN contains the energetic nitro groups found in nitrocellulose (NC), but also acetyl functionalities, which lowered the polymer's sensitivity to heat and shock, and therefore improved its IM properties relative to NC. The formulation, development and small-scale characterization testing of several CAN-based propellants were done. The formulations, using insensitive energetic solid fillers and high-nitrogen modifiers in place of nitramine were completed. The small scale characterization testing, such as closed bomb testing, small scale sensitivity, thermal stability, and chemical compatibility were done. The mechanical response of the pro-pellants under high-rate uni-axial compression at, hot, cold, and ambient temperatures were also completed. Critical diameter testing, hot fragment conductive ignition (HFCI) tests were done to evaluate the propellants' responses to thermal and shock stimuli. Utilizing the propellant chemical composition, theoretical predictions of erosivity were completed. All the small scale test results were utilized to down-select the promising CAN based formulations for large scale demonstration testing such as the ballistic performance and fragment impact testing in the 105 mm M67 artillery charge configurations. The test results completed in the small and large scale testing are discussed.

  8. Formulation development and characterization of cellulose acetate nitrate based propellants for improved insensitive munitions properties

    Directory of Open Access Journals (Sweden)

    Thelma Manning

    2014-06-01

    Full Text Available Cellulose acetate nitrate (CAN was used as an insensitive energetic binder to improve the insensitive munitions (IM properties of gun propellants to replace the M1 propellant used in 105 mm artillery charges. CAN contains the energetic nitro groups found in nitrocellulose (NC, but also acetyl functionalities, which lowered the polymer's sensitivity to heat and shock, and therefore improved its IM properties relative to NC. The formulation, development and small-scale characterization testing of several CAN-based propellants were done. The formulations, using insensitive energetic solid fillers and high-nitrogen modifiers in place of nitramine were completed. The small scale characterization testing, such as closed bomb testing, small scale sensitivity, thermal stability, and chemical compatibility were done. The mechanical response of the propellants under high-rate uni-axial compression at, hot, cold, and ambient temperatures were also completed. Critical diameter testing, hot fragment conductive ignition (HFCI tests were done to evaluate the propellants' responses to thermal and shock stimuli. Utilizing the propellant chemical composition, theoretical predictions of erosivity were completed. All the small scale test results were utilized to down-select the promising CAN based formulations for large scale demonstration testing such as the ballistic performance and fragment impact testing in the 105 mm M67 artillery charge configurations. The test results completed in the small and large scale testing are discussed.

  9. Synthesis, characterization and DFT calculations of electronic and optical properties of YbPO4

    International Nuclear Information System (INIS)

    Highlights: • Single crystals of YbPO4 were synthesized and characterized. • Electronic structure and optical properties were investigated by DFT method. • The DFT method is based on a combination of the GGA and the LDA + U approaches. • The calculated values were compared to the phosphate experimental data. - Abstract: YbPO4 crystals were synthesized by solid-state reaction and characterized by X-ray diffraction, infrared and Raman spectroscopies. The electronic structure and optical properties of YbPO4 such as the energy band structures, density of states and chemical bonds were calculated with the Density Functional Theory (DFT) for the first time. We present a combination of the GGA and the LDA + U approaches in order to obtain appropriate results due to the strong Coulomb repulsion between the highly localized 4f electrons of rare earth atoms. The linear photon-energy-dependent dielectric functions, conductivity and some optical constants such as refractive index, reflectivity and absorption coefficients were determined. The calculated total and partial densities of states indicate that the top of valance band is built upon O-2p states with P-3p states via σ (P–O) interactions, and the conduction bands mostly originate from Yb-5d states

  10. Characterization of the surface properties of nitrogen-enriched carbons by inverse gas chromatography methods

    Energy Technology Data Exchange (ETDEWEB)

    Vagner, C.; Finqueneisel, G.; Zimny, T.; Burg, P.; Grzyb, B.; Machnikowski, J.; Weber, J.V. [University of Metz, St. Avold (France)

    2003-07-01

    The characterization of the surface properties of carbonaceous materials by inverse gas chromatography (IGC) techniques is described. The cokes investigated were produced by the co-pyrolysis of a coal-tar pitch (CTP) with different amounts of polyacrylonitrile (PAN) as a possible method to synthesize carbonaceous materials enriched in nitrogen. IGC at infinite dilution and LSER (linear solvation energy relationship) techniques were used to determine the physical and chemical surface properties of the cokes. In general, the surface free energy of adsorption is due to both dispersive and specific interactions. The dispersive component of the surface free energy was determined using n-alkane probes. For the specific component, which is primarily due to acid-base interactions, different polar probes were used. The LSER method was applied to improve our understanding of the adsorption process in terms of molecular interactions. We show that, to characterize dispersive interactions using n-alkanes, the LSER and IGC methods are equivalent. On the other hand, with both methods we find that all the samples present acidic and basic characteristics. However, the sensitivity of the LSER method does not allow one to discriminate between the three samples in terms of specific interactions.

  11. Characterization and luminescent properties of Eu3+ doped Gd2Zr2O7 nanopowders

    International Nuclear Information System (INIS)

    Highlights: • Nanopowders Gd2Zr2O7 doped by europium ions (Eu3+) have been synthesized. • Their luminescence properties have been measured at room temperature. • The temporal evolution of laser induced phenomena are presented using time-resolved technique. • Lifetime analysis for luminescence bands in emission spectra has been done. - Abstract: Nanopowders based on gadolinium zirconium oxide (Gd2Zr2O7) doped by europium ions (Eu3+) were successfully prepared using a flame combustion method. This material is suitable for various optical devices. The structure of prepared materials has been confirmed and characterized using X-ray powder diffraction (XRD), scanning electron microscope (SEM) and photoluminescence (PL) techniques. The luminescence properties of synthesized nanopowders were characterized by emission spectra and luminescence lifetimes by using the streak camera system. PL spectra were obtained at three different excitation wavelengths (Optical Parametric Oscilator (OPO) at 360 nm, laser diode at 365 nm and Ar laser line at 514.5 nm). The strong emission lines at 611 nm and 630 nm corresponding to the 5D0 → 7F2 long lived transition could be used as a new red light source in optical devices

  12. Preliminary Characterization of the Probiotic Properties of Candida Famata and Geobacillus Thermoleovorans

    Directory of Open Access Journals (Sweden)

    A Bakhrouf

    2011-12-01

    Full Text Available Background and Objective: Probiotics are live microbial feed supplements which beneficially affect the host animal by improving its intestinal microbial balance, producing metabolites which inhibit the colonization or growth of other microorganisms or by competing with them for resources such as nutrients or space. The aim of this study was to investigate the probiotic properties of Candida famata and Geobacillus thermoleovorans.Material and Methods: In this study, yeast and bacterial strains isolated from pure oil waste were identified using Api 50 CHB and Api Candida Systems and their probiotic properties were studied through antimicrobial activity, biofilm production, adherence assay and enzymatic characterization.Results and Conclusion: According to biochemical analyses, these strains corresponded to Geobacillus thermoleovorans and Candida famata. Antagonism assay results showed that the tested strains have an inhibitory effect against tested pathogenic bacteria. The yeast Candida famata was unable to produce biofilm on Congo Red Agar (CRA, while the bacterial strain was a slime producer. Adherence assays to abiotic surfaces revealed that the investigated strains were fairly adhesive to polystyrene with values ranging from 0.18 to 0.34 at 595 nm. The enzymatic characterization revealed that the tested strains expressed enzymes such as phosphatase alkaline, esterase lipase (C8, amylase, lipase, lecitenase and caseinase. The obtained results may allow the isolated strains to be considered as having the potential to be candidate probiotics.

  13. Synthesis, characterization and DFT calculations of electronic and optical properties of YbPO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Khadraoui, Z.; Horchani-Naifer, K.; Ferhi, M., E-mail: ferhi.mounir@gmail.com; Ferid, M.

    2015-08-18

    Highlights: • Single crystals of YbPO{sub 4} were synthesized and characterized. • Electronic structure and optical properties were investigated by DFT method. • The DFT method is based on a combination of the GGA and the LDA + U approaches. • The calculated values were compared to the phosphate experimental data. - Abstract: YbPO{sub 4} crystals were synthesized by solid-state reaction and characterized by X-ray diffraction, infrared and Raman spectroscopies. The electronic structure and optical properties of YbPO{sub 4} such as the energy band structures, density of states and chemical bonds were calculated with the Density Functional Theory (DFT) for the first time. We present a combination of the GGA and the LDA + U approaches in order to obtain appropriate results due to the strong Coulomb repulsion between the highly localized 4f electrons of rare earth atoms. The linear photon-energy-dependent dielectric functions, conductivity and some optical constants such as refractive index, reflectivity and absorption coefficients were determined. The calculated total and partial densities of states indicate that the top of valance band is built upon O-2p states with P-3p states via σ (P–O) interactions, and the conduction bands mostly originate from Yb-5d states.

  14. Characterizing optical properties and spatial heterogeneity of human ovarian tissue using spatial frequency domain imaging.

    Science.gov (United States)

    Nandy, Sreyankar; Mostafa, Atahar; Kumavor, Patrick D; Sanders, Melinda; Brewer, Molly; Zhu, Quing

    2016-10-01

    A spatial frequency domain imaging (SFDI) system was developed for characterizing ex vivo human ovarian tissue using wide-field absorption and scattering properties and their spatial heterogeneities. Based on the observed differences between absorption and scattering images of different ovarian tissue groups, six parameters were quantitatively extracted. These are the mean absorption and scattering, spatial heterogeneities of both absorption and scattering maps measured by a standard deviation, and a fitting error of a Gaussian model fitted to normalized mean Radon transform of the absorption and scattering maps. A logistic regression model was used for classification of malignant and normal ovarian tissues. A sensitivity of 95%, specificity of 100%, and area under the curve of 0.98 were obtained using six parameters extracted from the SFDI images. The preliminary results demonstrate the diagnostic potential of the SFDI method for quantitative characterization of wide-field optical properties and the spatial distribution heterogeneity of human ovarian tissue. SFDI could be an extremely robust and valuable tool for evaluation of the ovary and detection of neoplastic changes of ovarian cancer. PMID:26822943

  15. Quantitative characterization of the microstructure and transport properties of biopolymer networks

    International Nuclear Information System (INIS)

    Biopolymer networks are of fundamental importance to many biological processes in normal and tumorous tissues. In this paper, we employ the panoply of theoretical and simulation techniques developed for characterizing heterogeneous materials to quantify the microstructure and effective diffusive transport properties (diffusion coefficient De and mean survival time τ) of collagen type I networks at various collagen concentrations. In particular, we compute the pore-size probability density function P(δ) for the networks and present a variety of analytical estimates of the effective diffusion coefficient De for finite-sized diffusing particles, including the low-density approximation, the Ogston approximation and the Torquato approximation. The Hashin–Strikman upper bound on the effective diffusion coefficient De and the pore-size lower bound on the mean survival time τ are used as benchmarks to test our analytical approximations and numerical results. Moreover, we generalize the efficient first-passage-time techniques for Brownian-motion simulations in suspensions of spheres to the case of fiber networks and compute the associated effective diffusion coefficient De as well as the mean survival time τ, which is related to nuclear magnetic resonance relaxation times. Our numerical results for De are in excellent agreement with analytical results for simple network microstructures, such as periodic arrays of parallel cylinders. Specifically, the Torquato approximation provides the most accurate estimates of De for all collagen concentrations among all of the analytical approximations we consider. We formulate a universal curve for τ for the networks at different collagen concentrations, extending the work of Torquato and Yeong (1997 J. Chem. Phys. 106 8814). We apply rigorous cross-property relations to estimate the effective bulk modulus of collagen networks from a knowledge of the effective diffusion coefficient computed here. The use of cross-property

  16. Novel Methodology for Characterizing Regional Variations in the Material Properties of Murine Aortas.

    Science.gov (United States)

    Bersi, Matthew R; Bellini, Chiara; Di Achille, Paolo; Humphrey, Jay D; Genovese, Katia; Avril, Stéphane

    2016-07-01

    Many vascular disorders, including aortic aneurysms and dissections, are characterized by localized changes in wall composition and structure. Notwithstanding the importance of histopathologic changes that occur at the microstructural level, macroscopic manifestations ultimately dictate the mechanical functionality and structural integrity of the aortic wall. Understanding structure-function relationships locally is thus critical for gaining increased insight into conditions that render a vessel susceptible to disease or failure. Given the scarcity of human data, mouse models are increasingly useful in this regard. In this paper, we present a novel inverse characterization of regional, nonlinear, anisotropic properties of the murine aorta. Full-field biaxial data are collected using a panoramic-digital image correlation (p-DIC) system. An inverse method, based on the principle of virtual power (PVP), is used to estimate values of material parameters regionally for a microstructurally motivated constitutive relation. We validate our experimental-computational approach by comparing results to those from standard biaxial testing. The results for the nondiseased suprarenal abdominal aorta from apolipoprotein-E null mice reveal material heterogeneities, with significant differences between dorsal and ventral as well as between proximal and distal locations, which may arise in part due to differential perivascular support and localized branches. Overall results were validated for both a membrane and a thick-wall model that delineated medial and adventitial properties. Whereas full-field characterization can be useful in the study of normal arteries, we submit that it will be particularly useful for studying complex lesions such as aneurysms, which can now be pursued with confidence given the present validation. PMID:27210500

  17. Characterization of mechanical and geometrical properties of a tube with axial and circumferential guided waves.

    Science.gov (United States)

    Yeh, Cheng-Hung; Yang, Che-Hua

    2011-05-01

    Guided waves propagating in cylindrical tubes are frequently applied for the characterization of material or geometrical properties of tubes. In a tube, guided waves can propagate in the axial direction and called axial guided waves, or in the circumferential direction called circumferential guided waves. Dispersion spectra for the axial and circumferential guided waves share some common behaviors and however exhibit some particular behaviors of their own. This study provides an investigation with theoretical modeling, experimental measurements, and a simplex-based inversion procedure to explore the similarity and difference between the axial guided waves and circumferential guided waves, aiming at providing useful information while axial and circumferential guided waves are applied in the area of material characterization. The sensitivity to the radius curvature for the circumferential guided waves dispersion spectra is a major point that makes circumferential guided waves different from axial guided waves. For the purpose of material characterization, both axial and circumferential guided waves are able to extract an elastic moduli and wall-thickness information from the dispersion spectra, however, radius information can only be extracted from the circumferential guided waves spectra. PMID:21211810

  18. Hydrophilic olive cake extracts: Characterization by physicochemical properties and Cu(II) complexation

    International Nuclear Information System (INIS)

    Disposed olive cake generates hydrophilic components that can be mobilized in the aquatic environment. This paper deals with the characterization of such components, isolated by alkaline extraction. It is shown that these substances possess properties very much resembling humic acid, including a substantial inventory of proton exchanging groups. Extraction and purification of the hydrophilic components from the disposed olive cake was performed by the standard approach for isolation of humic acids from solid sources, i.e. alternating alkaline dissolution and acid flocculation, leaving the purified extract in the protonated form. The purified sample was characterized by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), Fourier Transform Infra Red Spectroscopy (FTIR), UV-vis, Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) and Asymmetrical Flow Field-Flow Fractionation (AFFFF). The complex formation properties were investigated by potentiometry using Cu(II) ion selective electrode under atmospheric conditions at I = 0.1 M NaClO4 (aqueous solution) and pH 6. The formation constant for the CuHA complex is found to be log β = 5.3 ± 0.4 which is close to the corresponding value (log β = 5.2 ± 0.4) obtained from similar investigations with the commercially available Aldrich humic acid (this study) and corresponding published values for various humic acids. Both, structural properties and complex formation data show that the olive cake extract has considerable similarities with humic acids from different sources, pointing towards potential similarities in environmental behavior and impact.

  19. Manganese ferrite prepared using reverse micelle process: Structural and magnetic properties characterization

    Energy Technology Data Exchange (ETDEWEB)

    Hashim, Mohd, E-mail: md.hashim09@gmail.com [Department of Physics, Aligarh Muslim University, Aligarh 202002 (India); Shirsath, Sagar E. [Spin Device Technology Centre, Department of Engineering, Shinshu University, Nagano 380-8553 (Japan); Meena, S.S. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Mane, M.L. [Department of Physics, S.G.R.G. Shinde Mahavidyalaya, Paranda 413502, MS (India); Kumar, Shalendra [School of Materials Science and Engineering, Changwon National University, Changwon, Gyeongnam 641-773 (Korea, Republic of); Bhatt, Pramod [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kumar, Ravi [Centre for Material Science Engineering, National Institute of Technology, Hamirpur, HP (India); Prasad, N.K.; Alla, S.K. [Deptartment of Metallurgical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005 (India); Shah, Jyoti; Kotnala, R.K. [National Physical Laboratory (CSIR), Dr. K.S. Krishnan Road, New Delhi 110012 (India); Mohammed, K.A. [Department of Mathematics & Physics Sciences, College of Arts and Sciences, University of Nizwa, Nizwa (Oman); Şentürk, Erdoğan [Department of Physics, Sakarya University, Esentepe, 54187 Sakarya (Turkey); Alimuddin [Department of Physics, Aligarh Muslim University, Aligarh 202002 (India)

    2015-09-05

    Highlights: • Preparation of Mn{sup 3+} substituted MnFe{sub 2}O{sub 4} ferrite by Reverse microemulsion process. • Characterization by XRD, SEM, VSM, Mössbauer spectroscopy and dielectric measurements techniques. • Magnetic properties of MnFe{sub 2}O{sub 4} enhanced after Mn{sup 3+} substitution. • The dielectric constant and ac conductivity increased with Mn{sup 3+} substitution. - Abstract: Reverse microemulsion process was employed to prepare of nanocrystalline Mn{sup 3+} substituted MnFe{sub 2−x}Mn{sub x}O{sub 4} ferrites. The structural, magnetic and dielectric properties were studied for different concentrations of Mn{sup 3+}. The structural and microstructural properties were analyzed using X-ray diffraction technique (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy techniques. The phase identification of the materials was studied by Rietveld refined XRD patterns which reveals single phase with cubic symmetry for the samples. The lattice parameters were ranged in between 8.369 and 8.379 Å and do not show any significant change with the substitution of Mn{sup 3+}. The average particles size was found to be around 11 ± 3 nm. Magnetization results obtained from the vibrating sample magnetometer (VSM) confirm that the substitution of Mn{sup 3+} in MnFe{sub 2}O{sub 4} ferrite caused an increase in the saturation magnetization and coercivity. The dependence of Mössbauer parameters on Mn{sup 3+} substitution has been analyzed. Magnetic behavior of the samples were also studied at field cooled (FC) and zero field cooled (ZFC) mode. The dependence of Mössbauer parameters on Mn{sup 3+} substitution was also analyzed. All the magnetic characterization shows that Mn{sup 3+} substitution enhance the magnetic behavior of MnFe{sub 2}O{sub 4} ferrite nanoparticles.

  20. Synthesis, characterization and properties of yellow-light-emitting polyethers containing bis(styryl)anthracene units

    Energy Technology Data Exchange (ETDEWEB)

    Gioti, M., E-mail: mgiot@physics.auth.gr; Pitsalidis, C., E-mail: mgiot@physics.auth.gr; Tzounis, L.; Logothetidis, S., E-mail: logot@auth.gr [Laboratory for Thin Films-Nanosystems and Nanometrology (LTFN), Physics Department, Aristotle University of Thessaloniki, GR-54124 Thessaloniki (Greece); Andreopoulou, A. K.; Kallitsis, J. K. [Department of Chemistry, University of Patras, University Campus, Rio-Patras GR26504, Greece and Foundation for Research and Technology Hellas, Institute of Chemical Engineering Sciences (FORTH/ICE-HT), Platani Str., Patras GR26504 (Greece); Mparmpoutsis, E. [Department of Chemistry, University of Patras, University Campus, Rio-Patras GR26504 (Greece)

    2015-02-17

    Aromatic aliphatic polyethers containing bis(styryl)anthracene units in the main chain separated by flexible spacer of 11 (AND52) or 12 (AND53) methylene units, were synthesized and characterized aiming to be applied as emitting materials in polymer light emitting diode (PLED) devices. The polymers are soluble in common organic solvents and have average molecular weight of about 15kDa. Differentiations owing to an odd-even number of methylene units (χ=11 vs χ=12) are observed in their optical properties in solid state. Thin films as well as PLED devices were fabricated via conventional spin-coating process. Initially, various parameters have been investigated concerning the solubility of the polymers, the effect of film thickness on the electrical properties, and their thermal stability. The optical properties of the two polymers were investigated by NIR-Vis-far UV spectroscopic ellipsometry (SE). The accurate determination of the thickness and the optical constants (refractive index and dielectric function as a function of wavelength) were derived. These provide substantial insights into the final design of the optimum final multi-layer structure of the PLEDs, if we take into account that the external quantum efficiency (EQE) of electroluminescence (EL) strongly depends on the optical interference of the beams of emitted light that have been multiply reflected from the layer interfaces. The morphological characterization of the AND52 and AND53 polymeric thin films was carried out using atomic force microscopy (AFM), while current density-voltage (J-V) characteristics of the devices were studied by electrical measurements. The single PLED devices were switched on at relatively low operation voltages, showing the potential as backplanes for active matrix PLED applications. In this perspective, it can be assumed that further studies of the presented materials will enable the development of flexible PLEDs with the possibility to scale up their dimensions for bigger

  1. Synthesis, characterization and properties of yellow-light-emitting polyethers containing bis(styryl)anthracene units

    International Nuclear Information System (INIS)

    Aromatic aliphatic polyethers containing bis(styryl)anthracene units in the main chain separated by flexible spacer of 11 (AND52) or 12 (AND53) methylene units, were synthesized and characterized aiming to be applied as emitting materials in polymer light emitting diode (PLED) devices. The polymers are soluble in common organic solvents and have average molecular weight of about 15kDa. Differentiations owing to an odd-even number of methylene units (χ=11 vs χ=12) are observed in their optical properties in solid state. Thin films as well as PLED devices were fabricated via conventional spin-coating process. Initially, various parameters have been investigated concerning the solubility of the polymers, the effect of film thickness on the electrical properties, and their thermal stability. The optical properties of the two polymers were investigated by NIR-Vis-far UV spectroscopic ellipsometry (SE). The accurate determination of the thickness and the optical constants (refractive index and dielectric function as a function of wavelength) were derived. These provide substantial insights into the final design of the optimum final multi-layer structure of the PLEDs, if we take into account that the external quantum efficiency (EQE) of electroluminescence (EL) strongly depends on the optical interference of the beams of emitted light that have been multiply reflected from the layer interfaces. The morphological characterization of the AND52 and AND53 polymeric thin films was carried out using atomic force microscopy (AFM), while current density-voltage (J-V) characteristics of the devices were studied by electrical measurements. The single PLED devices were switched on at relatively low operation voltages, showing the potential as backplanes for active matrix PLED applications. In this perspective, it can be assumed that further studies of the presented materials will enable the development of flexible PLEDs with the possibility to scale up their dimensions for bigger

  2. Characterization of hydraulic fractures and reservoir properties of shale using natural tracers

    Science.gov (United States)

    Heath, J. E.; Gardner, P.; Kuhlman, K. L.; Malama, B.

    2013-12-01

    Hydraulic fracturing plays a major role in the economic production of hydrocarbon from shale. Current fracture characterization techniques are limited in diagnosing the transport properties of the fractures on the near wellbore scale to that of the entire stimulated reservoir volume. Microseismic reveals information on fracture geometries, but not transport properties. Production analysis (e.g., rate transient analysis using produced fluids) estimates fracture and reservoir flow characteristics, but often relies on simplified models in terms of fracture geometries and fluid storage and transport. We present the approach and potential benefits of incorporating natural tracers with production data analysis for fracture and reservoir characterization. Hydraulic fracturing releases omnipresent natural tracers that accumulate in low permeability rocks over geologic time (e.g., radiogenic 4He and 40Ar). Key reservoir characteristics govern the tracer release, which include: the number, connectivity, and geometry of fractures; the distribution of fracture-surface-area to matrix-block-volume; and the nature of hydrocarbon phases within the reservoir (e.g., methane dissolved in groundwater or present as a separate gas phase). We explore natural tracer systematics using numerical techniques under relevant shale-reservoir conditions. We evaluate the impact on natural tracer transport due to a variety of conceptual models of reservoir-transport properties and boundary conditions. Favorable attributes for analysis of natural tracers include the following: tracer concentrations start with a well-defined initial condition (i.e., equilibrium between matrix and any natural fractures); there is a large suite of tracers that cover a range of at least 7x in diffusion coefficients; and diffusive mass-transfer out of the matrix into hydraulic fractures will cause elemental and isotopic fractionation. Sandia National Laboratories is a multi-program laboratory managed and operated by

  3. Manganese ferrite prepared using reverse micelle process: Structural and magnetic properties characterization

    International Nuclear Information System (INIS)

    Highlights: • Preparation of Mn3+ substituted MnFe2O4 ferrite by Reverse microemulsion process. • Characterization by XRD, SEM, VSM, Mössbauer spectroscopy and dielectric measurements techniques. • Magnetic properties of MnFe2O4 enhanced after Mn3+ substitution. • The dielectric constant and ac conductivity increased with Mn3+ substitution. - Abstract: Reverse microemulsion process was employed to prepare of nanocrystalline Mn3+ substituted MnFe2−xMnxO4 ferrites. The structural, magnetic and dielectric properties were studied for different concentrations of Mn3+. The structural and microstructural properties were analyzed using X-ray diffraction technique (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy techniques. The phase identification of the materials was studied by Rietveld refined XRD patterns which reveals single phase with cubic symmetry for the samples. The lattice parameters were ranged in between 8.369 and 8.379 Å and do not show any significant change with the substitution of Mn3+. The average particles size was found to be around 11 ± 3 nm. Magnetization results obtained from the vibrating sample magnetometer (VSM) confirm that the substitution of Mn3+ in MnFe2O4 ferrite caused an increase in the saturation magnetization and coercivity. The dependence of Mössbauer parameters on Mn3+ substitution has been analyzed. Magnetic behavior of the samples were also studied at field cooled (FC) and zero field cooled (ZFC) mode. The dependence of Mössbauer parameters on Mn3+ substitution was also analyzed. All the magnetic characterization shows that Mn3+ substitution enhance the magnetic behavior of MnFe2O4 ferrite nanoparticles

  4. Regional Characterization of Soil Properties via a Combination of Methods from Remote Sensing, Geophysics and Geopedology

    Science.gov (United States)

    Meyer, Uwe; Fries, Elke; Frei, Michaela

    2016-04-01

    Soil is one of the most precious resources on Earth. Preserving, using and enriching soils are most complex processes that fundamentally need a sound regional data base. Many countries lack this sort of extensive data or the existing data must be urgently updated when land use recently changed in major patterns. The project "RECHARBO" (Regional Characterization of Soil Properties) aims at the combination of methods from remote sensing, geophysics and geopedology in order to develop a new system to map soils on a regional scale in a quick and efficient manner. First tests will be performed on existing soil monitoring districts, using newly available sensing systems as well as established techniques. Especially hyperspectral and infrared data measured from satellites or airborne platforms shall be combined. Moreover, a systematic correlation between hyperspectral imagery and gamma-ray spectroscopy shall be established. These recordings will be compared and correlated to measurements upon ground and on soil samples to get hold of properties such as soil moisture, soil density, specific resistance plus analytic properties like clay content, anorganic background, organic matter etc. The goal is to generate a system that enables users to map soil patterns on a regional scale using airborne or satellite data and to fix their characteristics with only a limited number of soil samples.

  5. Studies on solid phase synthesis,characterization and fluorescent property of the new rare earth complexes

    Directory of Open Access Journals (Sweden)

    Jianwei SHI

    2015-04-01

    Full Text Available Rare earth-β-diketone ligand complex luminescent material has stable chemical properties and excellent luminous property. Using europium oxide and (γ-NTA as raw materials, novel rare earth-β-dione complexes are synthesized by solid state coordination chemistry. The synthesis temperature and milling time are discussed for optimization. Experimental results show that the suitable reaction situation is at 50 ℃ and 20 h for solid-phase synthesis. The compositions and structures of the complexes are characterized by means of elemental analysis, UV-Vis and FTIR methods, and the phase stability of the complex is determined by using TG-DTA technique. It is proved that preparation of waterless binary rare earth complexes by the solid phase reaction method results in a higher product yield. The fluorescence spectra show that between Eu (Ⅲ and γ-NTA, there exists efficient energy transfer, and the rare earth complexes synthesis is an excellent red bright light-emitting material with excellent UV excited luminescence properties.

  6. Elastic property characterization of oxidized Si nanowires by contact-resonance atomic force microscopy

    Science.gov (United States)

    Stan, Gheorghe; Cook, Robert

    2010-03-01

    The synthesis and processing of materials into nanostructures opens new avenues for advancement and diversification of current electronic, optoelectronic, and sensor applications. Among these structures, Si NWs are distinctly remarkable as they bring the previous decades knowledge of silicon technology into nanoscale applications. From this perspective, the characterization and understanding of the mechanical properties of nonplanar Si-SiO2 interfaces are of significant utility in developing Si nanostructures for Si-based integrated circuits. To investigate the elastic properties of as-grown and oxidized Si NWs we have extended and specifically tailored the applicability of contact-resonance atomic force microscopy (CR- AFM). From such CR-AFM measurements, the effect of the compressive stress at the Si-SiO2 interface was revealed in a diameter dependence of the elastic modulus of oxidized Si NWs. A modified core-shell model that includes the interface stress developed during oxidation captures the observed dependence. The values of strain and stress as well as the width of the stressed transition region at the Si-SiO2 interface agree with those reported from simulations and other experiments. This novel approach advances CR-AFM applicability in investigating structure-mechanical property relationships at the nanoscale.

  7. Characterization of Regolith Volatile Transport and Storage Properties by The MECA MSP 2001 Lander Payload

    Science.gov (United States)

    Clifford, S. M.; Marshall, J.

    1999-01-01

    The diffusive and adsorptive properties of the Martian regolith influence the exchange of volatiles between the atmosphere and subsurface. Our quantitative knowledge of these properties is extremely poor -introducing substantial uncertainties in efforts to model long-term evolution of ground ice and diurnal, seasonal, and climatic cycles of CO2 and H20. This situation should significantly improve upon arrival of the 2001 Mars Surveyor Lander in 2002. In support of the Human Exploration and Development of Space (HEDS) enterprise, the 2001 mission will include a suite of instruments to characterize the nature of the Martian environment and assess whether it contains hazards that may threaten future human exploration. A major element of this effort is the Mars Environmental Compatibility Assessment (MECA) payload, which consists an optical microscopy system incorporating electrostatic, magnetic, and scratch-hardness materials testing palets, an atomic force microscope with imaging capabilities comparable to an SEM, a wet chemistry laboratory with four independent test cells, an electrometer on the robotic arm, material test patches, a camera also mounted on the arm, and a soil scoop for excavating down to about 50 cm into the soil. Although conceived to address the needs of HEDS, MECA payload is a sophisticated soil science laboratory that should provide a wealth of new data relevant to the volatile transport and storage properties of the regolith. Additional information os contained in the original.

  8. Synthesis, characterization and magnetic properties of Fe3O4 doped chitosan polymer

    International Nuclear Information System (INIS)

    Fe3O4 nanoparticles doped into chitosan films were prepared by the solution casting technique. Various samples were synthesized in atmospheric medium and in vacuum. The morphological properties of the samples were characterized by high resolution transmission electron microscopy (HR-TEM) and Scanning Electron Microscopy (SEM). The structural, magnetic, and microwave absorption properties of magnetic chitosan films have been carried out using the Vibrating Sample Magnetometer (VSM) and Ferromagnetic Resonance (FMR). It is shown that the composite polymer behaves like a superparamagnetic material with high blocking temperature. The effective magnetization shows gradual increments with the concentration of dopant Fe3O4 nanoparticles. The microwave absorption characteristic of superparamagnetic composite polymer shows low reflection loss. - Highlights: • Chitosan polymers doped with Fe3O4 are prepared by the solution casting technique. • The structural, magnetic, and microwave absorption properties of the samples are analyzed. • The polymer behaves like a superparamagnetic material with high blocking temperature. • The effective magnetization shows gradual increments with the concentration of Fe3O4. • The microwave absorption characteristic shows low reflection loss

  9. An experimental characterization of damping properties of thermal barrier coatings at elevated temperatures

    Science.gov (United States)

    Easterday, Oliver T.

    Modern gas turbine engines have routinely utilized thermal barrier coatings for the past three decades to coax greater thermodynamic efficiency out of jet engines. In service, it has been noted that these ceramic materials are also effective at suppressing high cycle fatigue in the engine components, increasing their respective fatigue life. Recent efforts have been made to mechanically characterize these materials; this has been a challenge as they are thin coatings, prone to history effects, and are materially nonlinear. Refinement of the apparatus have occurred and it is now desired to characterize them across a range of likely service temperatures. A free-free beam apparatus has been adapted to accomplish this. Important to achieving viable results is the design, analysis, and experimental validation of the chamber in regards to the free-free specimen being heat-able, modally detuned and free-hanging, and the preservation of a non-contacting excitation method. Critical to success is ensuring a near-isothermal heated beam specimen. After successful validation and calibration of the chamber, a common thermal barrier coating, 8-YSZ, was tested, primarily using the free-decay, logarithmic decrement method, using the chamber from 70-900degF. Materially non-linear behavior was observed and findings of material storage modulus and loss coefficient that are consistent with previous studies were obtained. The chamber was also used to characterize the bare metal beam blanks and bond-coat only specimens. The apparatus was found to be sensitive when determining the storage modulus and damping, more so than the baseline configuration. This was due to changes in design to proof it against high temperature. Resulting, it clearly characterized the anisotropic modulus of titanium and determined that bond coating had a negligible contribution to the beam system. Design life criteria with the properties of the coating could now be adopted across a range of temperatures.

  10. Synthesis, characterization and magnetic properties of monodisperse Ni, Zn-ferrite nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Sanjeev, E-mail: sanjeevkumar.dubey2@gmail.com [University of Petroleum and Energy Studies, Dehradun, Uttarakhand (India); Kumar, Pankaj [University of Petroleum and Energy Studies, Dehradun, Uttarakhand (India); Singh, Vaishali [University School of Basic and Applied Science (India); Kumar Mandal, Uttam [University of Chemical Technology, GGS Indraprastha University, Sector 16, Dwarka, Delhi 110403 (India); Kumar Kotnala, Ravinder [National Physical laboratory, New Delhi 110012 (India)

    2015-04-01

    Synthesization of monodisperse Ni, Zn-ferrite (Ni{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4}, x=1, 0.8, 0.6, 0.5, 0.4, 0.2, 0.0) nanocrystals has been achieved by the inverse microemulsion method using CTAB as surfactant and kerosene as an oil phase. The detailed characterization of the synthesized nanocrystals and measurement of the magnetic properties has been done by techniques like X-ray diffraction (XRD), field emission transmission electron microscopy (FETEM), Fourier transform infrared spectroscopy (FITR) and Vibrating Sample Magnetometer (VSM) respectively. The relationship between the structure and composition of the nanocrystals with magnetic properties has been investigated. The nanocrystals size is found to be in the range 1–5 nm. The effect of Zn substitution on size and magnetic properties has been studied. It has been observed that magnetism changed from ferromagnetic at X= 0 to super paramagnetic to paramagnetic at X=1 as Zn concentration increased. The Curie temperature is found to decrease with an increase in Zn concentration. - Highlights: • Reverse microemulsion route is very facile route for synthesis of Ni{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4} ferrite. • Presence of Zn changes the structural and magnetic properties of the Zn substituted NiFe{sub 2}O{sub 4.} • The lattice constant increases with the increase in Zn substitution. • The curie temperature decreases with Zn concentration appreciably. • Magnetic behavior varies from ferromagnetic at x=0 to superparamagnetic to paramagnetic at x=1.

  11. Characterization of Cirrus Cloud Properties by Airborne Differential Absorption and High Spectral Resolution Lidar Measurements

    Science.gov (United States)

    Ehret, G.; Gross, S.; Schäfler, A.; Wirth, M.; Fix, A.; Kiemle, C.

    2014-12-01

    Despite the large impact of cirrus clouds on the Earth's climate system, their effects are still only poorly understood. Our knowledge of the climate effect of cirrus clouds is mainly based on theoretical simulations using idealized cloud structure and microphysics, as well as radiative transfer approximations. To improve the representation of cirrus clouds in idealized simulations and circulation models, we need a better understanding of the micro- and macrophysical properties of cirrus clouds. Airborne lidar measurements provide two-dimensional information of the atmospheric structure, and are thus a suitable tool to study the fine-structure of cirrus clouds, as well as their macrophysical properties. Aerosol and water vapor was measured with the airborne high spectral resolution lidar (HSRL) and differential absorption lidar (DIAL) system WALES of the German Aerospace Center (DLR), Oberpfaffenhofen. The system was operated onboard the German high altitude and long range research aircraft HALO during the Next-generation remote sensing for validation studies campaign (NARVAL) in December 2013 over the tropical North-Atlantic and in January 2014 out of Iceland, and during the ML-Cirrus campaign in March/April 2014 over Central and Southern Europe. During NARVAL 18 flights with more than 110 flight hours were performed providing a large number of cirrus cloud overpasses with combined lidar and radar instrumentation. In the framework of the ML-Cirrus campaign 17 flights with more than 80 flight hours were performed to characterize cirrus cloud properties in different environmental conditions using a combination of remote sensing (e.g. lidar) and in-situ observations. In our presentation we will give a general overview of the campaigns and of the WALES measurements. We will show first results from the aerosol and water vapor lidar measurements with focus on the structure of cirrus clouds, the humidity distribution within and outside the cloud and on the impact of the

  12. Preparation, characterization and optoelectronic properties of nanodiamonds doped zinc oxide nanomaterials by a ball milling technique

    Science.gov (United States)

    Ullah, Hameed; Sohail, Muhammad; Malik, Uzma; Ali, Naveed; Bangash, Masroor Ahmad; Nawaz, Mohsan

    2016-07-01

    Zinc oxide (ZnO) is one of the very important metal oxides (MOs) for applications in optoelectronic devices which work in the blue and UV regions. However, to meet the challenges of obtaining ZnO nanomaterials suitable for practical applications, various modifications in physico-chemical properties are highly desirable. One of the ways adopted for altering the properties is to synthesize composite(s) of ZnO with various reinforcements. Here we report on the tuning of optoelectronic properties of ZnO upon doping by nanodiamonds (NDs) using the ball milling technique. A varying weight percent (wt.%) of NDs were ball milled for 2 h with ZnO nanoparticles prepared by a simple precipitation method. The effects of different parameters, the calcination temperature of ZnO, wt.% of NDs and mechanical milling upon the optoelectronic properties of the resulting ZnO–NDs nanocomposites have been investigated. The ZnO–NDs nanocomposites were characterized by IR spectroscopy, powder x-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDX). The UV-vis spectroscopy revealed the alteration in the bandgap energy (Eg ) of ZnO as a function of the calcination temperature of ZnO, changing the concentration of NDs, and mechanical milling of the resulting nanocomposites. The photoluminescence (PL) spectroscopy showed a decrease in the deep level emission (DLE) peaks and an increase in near-band-edge transition peaks as a result of the increasing concentration of NDs. The decrease in DLE and increase in band to band transition peaks were due to the strong interaction between the NDs and the Zn+; consequently, the Zn+ concentration decreased on the interstitial sites.

  13. Syntheses, characterization and properties of silver, copper and palladium complexes from bis(oxazoline)-containing ligands

    International Nuclear Information System (INIS)

    The reactions of 2,6-di(2-oxazolyl)pyridine (L1) and 2,6-bis[(S)-4-phenyl-2-oxazolyl]pyridine (L2) with silver, copper and palladium salts to yield six new complexes: ([Ag5(L1)5](BF4)5)n (1), ([Ag(L1)](SbF6))n (2), [Cu4I4(L1)2] (3), [Cu6I6(L1)2] (4), [Pd(L′1)(OAc)] (5), [Pd(L′2)Cl] (6), which were fully characterized by single-crystal and powder X-ray diffraction, IR, elemental and thermogravimetric analyses. 1 and 2 are a pair of Ag-oxazoline helical chain structure complexes. The spiral directions of chains are opposite in 1, while identical in 2; the measurement of CD spectra can further confirm their meso and chiral structures. Complexes 3 and 4 show eight-nuclear and twelve-nuclear iodine–cuprous cluster structure. Their structural diversity is induced by different molar ratios of CuI:L1. Complexes 5 and 6 are discrete mononuclear palladium complexes. In situ oxazolyl-ring-opening reactions take place in the syntheses of them and the L1 and the L2 were transformed to their oxazolyl-ring opened derivatives L′1 and L′2. Moreover, fluorescence, non-linear optical properties, and ferroelectric properties have been investigated. - Graphical abstract: 2,6-di(2-oxazolyl)pyridine (L1) reacts with silver and copper salts to yield helical and cluster structure complexes. - Highlights: • Helical and cluster structure complexes. • In situ oxazolyl-ring-opening reactions. • Fluorescence, non-linear optical properties, and ferroelectric properties

  14. Mechanical and structural characterization of the poroviscoelastic properties of natural and synthetic biocomposites

    Science.gov (United States)

    Hayot, Celine M.

    Rubber-like insect cuticle is a light fibrous composite which exhibits great deformability and long range elasticity due to the presence of a large amount of the elastomeric protein resilin. The presence of resilin in specific locations in the insect body leads to the assumption that its main function is loss-free storage of energy. The composition of the cuticle reveals the presence of a resilin matrix in which chitin fibers are embedded. Nanoindentation testing was used to study the differences in the mechanical properties of the structure between genders and wing morphs of the sand field cricket, Gryllus firmus. The results provide insight into the structure-function relations associated with the properties of insect rubber-like cuticle from different morphs and genders. An understanding of this relationship is of great importance if synthetic bio-inspired loss-free composites are to be manufactured. Inspired by the rubber-like cuticle, a synthetic composite was made of the elastomeric protein elastin in which polycaprolactone fibers were embedded. Nanoindentation testing was used to investigate the differences in the mechanical properties of the synthetic rubber-like composite between materials crosslinked for different time periods (2, 4, and 6 hours). Furthermore, the characterization of the viscoelastic properties of the synthetic composite by nanoindentation reveals the composite crosslinked for 4 hours as an optimized strain energy storage material when employed at low frequency load cycles. Also, investigating the microstructure of the synthetic composite shows the presence of pores which, under deformation, are responsible for the generation of a simultaneous mechanical response to viscoelasticity which is known as poroelasticity. Thus in this dissertation a methodology is developed to decouple the viscoelastic and the poroelastic behavior by combining the nanoindentation technique with finite element simulations. With this approach, it is possible to

  15. A novel pH-sensitive polymeric fluorescent probe: Synthesis, characterization and optical properties

    International Nuclear Information System (INIS)

    A novel initiator containing proflavine derivative moiety, 3,6-dibromo-isobutyramide acridine (DIA), was synthesized and initiated the atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA). A water-soluble monomer, N,N-dimethylacrylamide (DMAA) was also initiated by DIA for comparison. The obtained fluorescent polymers, PMMA-DIA and PDMAA-DIA, were characterized by 1H NMR, GPC and TGA. The emission spectra of the fluorescent polymers exhibit obvious changes in color and fluorescence intensity along with pH varied in range of 3.0-9.0. In addition, the obtained polymers present good film-forming capacity and the films also have a high quantum yield and pH response. Both oil-soluble PMMA-DIA and water-soluble PDMAA-DIA have steady optical and chemical properties by containing proflavine moiety in the main chain.

  16. Surface modification, characterization and adsorptive properties of a coconut activated carbon

    Science.gov (United States)

    Lu, Xincheng; Jiang, Jianchun; Sun, Kang; Xie, Xinping; Hu, Yiming

    2012-08-01

    A coconut activated carbon was modified using chemical methods. Different concentration of nitric acid oxidation of the conventional sample produced samples with weakly acidic functional groups. The oxidized samples were characterized by scanning electron micrograph, nitrogen absorption-desorption, Fourier transform infra red spectroscopy, Bothem method, pH titration, adsorption capacity of sodium and formaldehyde, and the adsorption mechanism of activated carbons was investigated. The results showed that BET surface area and pore volume of activated carbons were decreased after oxidization process, while acidic functional groups were increased. The surface morphology of oxidized carbons looked clean and eroded which was caused by oxidization of nitric acid. The oxidized carbons showed high adsorption capacity of sodium and formaldehyde, and chemical properties of activated carbon played an important role in adsorption of metal ions and organic pollutants.

  17. Synthesis, Characterization, Absorbance, Fluorescence and Non Linear Optical Properties of Some Donor Acceptor Chromophores

    Energy Technology Data Exchange (ETDEWEB)

    Asiri, Abdullah M.; Khan, Salman A.; Alamry, Kalid A. [King Abdulaziz University, Jeddah (Saudi Arabia); Al-Amoudi, Muhammed S. [Taif University, Taif (Saudi Arabia)

    2012-06-15

    Three carbazole chromophores featuring dicyano, cyano, ethyl acetate and dimethyl acetate groups as an acceptor moiety with a {pi}-conjugated spacer and N-methyl dibenzo[b]pyrole as donor were synthesized by Knovenagel condensation and characterized by IR, {sup 1}HNMR, {sup 13}CNMR, UV-vis, fluorescence spectroscopy, electrochemistry and theoretical B3LYP/6-311G* level whilst NLO properties and spectroscopic quantities were calculated. Calculations showed remarkable trend with HOMO located on the donor moiety and LUMO on the acceptors dicyano methylene, cyano, ethyl acetate methylene and dimethyl acetate methylene. In agreement with the calculations, solvatochromic, behavior intramolecular charge transfer band was observed in the visible region

  18. Hydrothermal Synthesis, Characterization, and Optical Properties of Ce Doped Bi2MoO6 Nanoplates

    Directory of Open Access Journals (Sweden)

    Anukorn Phuruangrat

    2014-01-01

    Full Text Available Undoped and Ce doped Bi2MoO6 samples were synthesized by hydrothermal reaction at 180°C for 20 h. Phase, morphology, atomic vibration, and optical properties were characterized by X-ray powder diffraction (XRD, X-ray photoelectron spectroscopy (XPS, Raman spectrophotometry, Fourier transform infrared (FTIR spectroscopy, scanning electron microscopy (SEM, transmission electron microscopy (TEM, selected area electron diffraction (SAED, and UV-visible spectroscopy. In this research, the products were orthorhombic Bi2MoO6 nanoplates with the growth direction along the [0b0], including the asymmetric and symmetric stretching and bending modes of Bi–O and Mo–O. Undoped and Ce doped Bi2MoO6 samples show a strong absorption in the UV region.

  19. Characterization of thermochemical properties of Al nanoparticle and NiO nanowire composites

    Science.gov (United States)

    Wen, John Z.; Ringuette, Sophie; Bohlouli-Zanjani, Golnaz; Hu, Anming; Nguyen, Ngoc Ha; Persic, John; Petre, Catalin F.; Zhou, Y. Norman

    2013-04-01

    Thermochemical properties and microstructures of the composite of Al nanoparticles and NiO nanowires were characterized. The nanowires were synthesized using a hydrothermal method and were mixed with these nanoparticles by sonication. Electron microscopic images of these composites showed dispersed NiO nanowires decorated with Al nanoparticles. Thermal analysis suggests the influence of NiO mass ratio was insignificant with regard to the onset temperature of the observed thermite reaction, although energy release values changed dramatically with varying NiO ratios. Reaction products from the fuel-rich composites were found to include elemental Al and Ni, Al2O3, and AlNi. The production of the AlNi phase, confirmed by an ab initio molecular dynamics simulation, was associated with the formation of some metallic liquid spheres from the thermite reaction.

  20. Preparation, characterization, photocatalytic properties of titania hollow sphere doped with cerium

    International Nuclear Information System (INIS)

    Ce-doped titania hollow spheres were prepared using carbon spheres as template and Ce-doped titania nanoparticles as building blocks. The Ce-doped titania nanoparticles were synthesized at low temperature. The prepared hollow spheres were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse reflectance spectrum (DRS). The effect of Ce content on the physical structure and photocatalytic properties of doped titania hollow sphere samples was investigated. Results showed that there was an optimal Ce-doped content (4%) for the photocatalytic activity of X-3B degradation. The apparent rate constant of the best one was almost 31 times as that of P25 titania. The mechanism of photocatalytic degradation of dyes under visible light irradiation was also discussed.

  1. Photoelectrochemical characterization and photocatalytic properties of mesoporous TiO 2 / ZrO 2 films

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available Optically transparent, crack-free mesoporous titania and zirconia-doped titania thin film photocatalysts were fabricated by sol-gel technique, using nonionic amphiphilic block copolymer Pluronic P123 as template. The structural and optical properties of these films were characterized using SEM, low-angle XRD, and UV/Vis spectroscopy, hexane adsorption investigation. Band gap energy and the position of flatband potentials were estimated by photoelectrochemical measurements. Enhancing of photocatalytic activity of zirconia-doped films relative to pure TiO 2 originates from an anodic shift of the valence band edge potential. Catalytic activity of mesoporous TiO 2 and TiO 2 / ZrO 2 ( 5 –50% of ZrO 2 films in the processes of Cr VI to Cr III photoreduction and 2,4-dinitroaniline photooxidation correlates with crystalline size and growth with increasing of specific surface area of the samples.

  2. -pyrrole substituted porphyrin-pyrene dyads using vinylene spacer: Synthesis, characterization and photophysical properties

    Indian Academy of Sciences (India)

    P Silviya Reeta; Ravi Kumar Kanaparthi; L Giribabu

    2013-03-01

    We have designed and synthesized donor-acceptor conjugates having donor pyrene at the pyrrole- position of either free-base porphyrin or Zn(II) porphyrin using vinylene spacer. Both the dyads have been completely characterized by elemental analysis,MALDI-MS, UV-Vis., and fluorescence (steady state and timeresolved) spectroscopies as well as cyclic voltammetry. The absorption maxima of both dyads are red-shifted by 8-12 nm. The ground state properties showed that there exist minimum - interaction between the aromatic subunits of these D-A systems. Quenched emission was observed in both the dyads when excited at 290 nm. The quenched emission explained in terms of intramolecular excitation energy transfer competes with the photo-induced electron transfer reaction in these D-A system.

  3. Thermoelectric Characterization of Electronic Properties of GaMnAs Nanowires

    Directory of Open Access Journals (Sweden)

    Phillip M. Wu

    2012-01-01

    Full Text Available Nanowires with magnetic doping centers are an exciting candidate for the study of spin physics and proof-of-principle spintronics devices. The required heavy doping can be expected to have a significant impact on the nanowires' electron transport properties. Here, we use thermopower and conductance measurements for transport characterization of Ga0.95Mn0.05As nanowires over a broad temperature range. We determine the carrier type (holes and concentration and find a sharp increase of the thermopower below temperatures of 120 K that can be qualitatively described by a hopping conduction model. However, the unusually large thermopower suggests that additional mechanisms must be considered as well.

  4. Synthesis, Characterization and Catalytic Properties of Perovskite LaFeO3 Nanoparticles

    Science.gov (United States)

    Afifah, Nur; Saleh, Rosari

    2016-04-01

    Orthorhombic structure of rare earth perovskite-type oxide LaFeO3 nanoparticles with light absorption properties in the visible range was prepared by co-precipitation method. The prepared nanoparticles was characterized by several measurements such as X-ray diffraction, energy dispersive X-ray, field emission scanning electron microscope, diffuse reflectance spectroscopy, vibrating sample magnetometer and electron spin resonance spectroscopy. Methylene blue was taken as the model pollutant to evaluate its photocatalytic, sonocatalytic, photosonocatalytic degradation in the presence of LaFeO3 nanoparticles. The degradation of methylene blue followed the pseudo-first order model in all three processes. The observed rate constants indicate that the photosonocatalytic was faster than the respective individual. Radical scavenger experiments revealed that holes were the predominant oxidative species involved in all three processes.

  5. Fabrication and characterization of multi-scale microlens arrays with anti-reflection and diffusion properties

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yung-Pin; Lee, Chih-Hsien; Wang, Lon A, E-mail: lon@ntu.edu.tw [Photonics and Nano-Structure Laboratory, Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan (China)

    2011-05-27

    In this paper, an effective method for fabricating artificial compound-eye structures is demonstrated. The fabrication of high fill factor microlens arrays (MLAs) with sub-wavelength structures (SWSs) on a polycarbonate (PC) substrate involves nanoimprint and thermo-extrusion techniques by using two different scales of nano/micromolds. In addition, the MLAs with SWSs on the PC substrate would be replicated on a polymethylmethacrylate (PMMA) millimeter concave surface by hot-embossing, forming three-level compound-eye structures. The optical properties of these samples are characterized. The transmittances of two-level PC and three-level PMMA compound structures are increased by 2.5% and 2%, and the uniformities are enhanced by 18% and 24%, respectively.

  6. Template synthesis, characterization and magnetic property of Fe nanowires-filled amorphous carbon nanotubes array

    International Nuclear Information System (INIS)

    A Fe nanowires-filled amorphous carbon nanotubes (FeNW-filled a-CNTs) array was synthesized by sequential growth of electrodeposited Fe nanowires and subsequent chemical vapour deposition of amorphous CNTs in the nanochannels of alumina template. Structural characterizations of as-prepared FeNW-filled a-CNTs were carried out via field emission scanning electron microscope (FE-SEM), x-ray diffraction (XRD), elemental mapping, high-resolution transmission electron microscope (HRTEM) and Raman scattering. The formation mechanism of such Fe/C nanoheterostructure was proposed according to the detailed HRTEM analyses. Furthermore, the room temperature magnetic property of the as-prepared FeNW-filled a-CNTs array was also investigated, and obvious anisotropic behaviour in magnetization was observed

  7. Characterization of anisotropy in viscoelastic properties of intra-abdominal soft tissues.

    Science.gov (United States)

    Deo, Dhanannjay; Singh, Tejinder Paul; Dunnican, Ward; De, Suvranu

    2009-01-01

    A portable instrumentation rig is presented for characterizing nonlinear viscoelastic anisotropic response of intra-abdominal organ-tissues. Two linearly independent in-situ experiments are performed at each indentation site on the intra-abdominal organ, by subjecting the organ to 1) normal and 2) tangential displacement stimuli using the above robotic device. For normal indentation experiments, the indenter is ramped into the tissue and held for 10 seconds before sinusoidal indentation stimuli are applied. For tangential (shear) loading, the indenter tip is rigidly glued to the soft tissue surface. Sinusoidal displacement stimuli are then applied laterally in the tangential plane and the force response is recorded. Tangential loading is repeated along orthogonal directions to measure in-plane mechanical properties. Combined analysis of both experiments leads to assessment of anisotropy. In situ experiments on fresh human cadavers are currently under way at the Albany Medical College. PMID:19377118

  8. Zinc oxide nanoparticle-coated films: fabrication, characterization, and antibacterial properties

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Yunhong, E-mail: y.jiang@leeds.ac.uk [University of Leeds, Institute of Particle Science and Engineering (United Kingdom); O’Neill, Alex J. [University of Leeds, School of Molecular and Cellular Biology (United Kingdom); Ding, Yulong [University of Leeds, Institute of Particle Science and Engineering (United Kingdom)

    2015-04-15

    In this article, novel antibacterial PVC-based films coated with ZnO nanoparticles (NPs) were fabricated, characterized, and studied for their antibacterial properties. It was shown that the ZnO NPs were coated on the surface of the PVC films uniformly and that the coating process did not affect the size and shape of the NPs on the surface of PVC films. Films coated with concentrations of either 0.2 or 0.075 g/L of ZnO NPs exhibited antibacterial activity against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria, but exhibited no antifungal activity against Aspergillus flavus and Penicillium citrinum. Smaller particles (100 nm) exhibited more potent antibacterial activity than larger particles (1000 nm). All ZnO-coated films maintained antibacterial activity after 30 days in water.

  9. Preparation and property characterization of PAA/Fe3O4 nanocomposite

    Institute of Scientific and Technical Information of China (English)

    WEI Shanshan; ZHANG Yi; XU Jiarui

    2007-01-01

    PAA/Fe3O4 nanocomposites were prepared by mixing nano-Fe3O4 and polyacrylic acid(PAA)ethanol solution and then evaporating the solvent.The materials were characterized by transmission electron microscope(TEM),Fourier transform infrared spectroscope(FTIR),thermogravimetry analysis (TGA),dynamic ultra-micro hardness tester (DUMHT)and superconducting quantum interference device (SQUID)magnetometer.Results showed that PAA coordinated with nano-Fe3O4 to form a cross-linking structure.The presence of nano-Fe3O4 enhanced the thermal stability of the nanocomposite.The elasticity and hardness of the nanocomposite increased,and the indentation depth reduced with the increase of Fe3O4 content in the composites.The nanocomposites showed superparamagnetic properties at 300K.

  10. Preparation,characterization and properties studies of quinine-imprinted polymer in the aqueous phase

    Institute of Scientific and Technical Information of China (English)

    He Jianfeng; Liu Lan; Yang Guilan; Deng Qinying

    2006-01-01

    The uniform-sized spherical molecularly imprinted polymers were successfully prepared through molecular imprinting technology by two-step seed swelling and mini-emulsion polymerization in the aqueous condition using quinine as template molecules and methacrylic acid (MAA)as functional monomer.The polymers were characterized by IR spectra,thermal-weight analysis,scanning electron microscope and laser particle size analysis.The properties of imprinted polymers were investigated in different organic phases and aqueous media.In the organic media,results suggested that polar interactions(hydrogen bonding,ionic interactions)between acidic monomer/polymer and template molecules are mainly responsible for the binding and recognition;whereas in the aqueous medium,a considerable recognition effect was also obtained where the ionic(electrostatic)interaction and hydrophobic interaction play an important role.The experiments of binding different substrates indicated that the MIPs possessed an excellent rebinding ability and inherent selectivity to quinine.

  11. Characterization of Compressive Properties of Polymer Foam Materials Using DIC and a Modified Arcan Fixture

    DEFF Research Database (Denmark)

    Taher, Siavash Talebi; Thomsen, Ole Thybo; Dulieu-Barton, J. M.

    2013-01-01

    A modified Arcan fixture (MAF) has been developed to characterize polymer foam materials with respect to their tensile, compressive, shear and bidirectional mechanical properties at room and at elevated temperatures. The MAF enables the realization of pure compression or high compression to shear...... bidirectional loading conditions that are not possible with conventional Arcan fixtures. The MAF is attached to a standard universal test machine, equiped with an environmental chamber, using specially designed grips that do not constrain the specimen wrt. rotations, and hence reduces paristic effects due to...... misalignment. The objective is to use digital image correlation (DIC) to obtain the unidirectional and bidirectional elastic coefficients and the stress-strain response to failure of polymer foam materials at elevated tempreature. To account for nonhomogeneity of the strain field in the specimen cross sections...

  12. Improved production, characterization and flocculation properties of poly (-glutamic acid produced from Bacillus Subtilis

    Directory of Open Access Journals (Sweden)

    Bhunia B

    2012-04-01

    Full Text Available Bacillus subtilis 2063 produced extracellular biopolymer whichshowed excellent flocculation activity. The biopolymer wasconfirmed as poly (γ-glutamic acid (PGA by using productcharacterization. HPLC profile showed that molecular weight ofPGA was found to be 5.8×106 Da. Improved production,Characterization and flocculation properties of PGA produced byBacillus species were studied. PGA produced by B. subtilis wasdevoid of any polysaccharides. The flocculating activity wasmarkedly stimulated by the addition of cations. The pH of reaction mixture also influenced the flocculating activity. Glycerol and ammonium chloride were found to be most useful carbon and nitrogen sources. An overall 4.24-fold increase in protease production was achieved in the design medium composed with Glycerol and ammonium chloride as a carbon and nitrogen sources as compared with basal media. PGA production increased significantly with optimized medium (21.42 gl-1 when compared with basal medium (5.06 gl-1.

  13. Surface modification, characterization and adsorptive properties of a coconut activated carbon

    International Nuclear Information System (INIS)

    A coconut activated carbon was modified using chemical methods. Different concentration of nitric acid oxidation of the conventional sample produced samples with weakly acidic functional groups. The oxidized samples were characterized by scanning electron micrograph, nitrogen absorption-desorption, Fourier transform infra red spectroscopy, Bothem method, pH titration, adsorption capacity of sodium and formaldehyde, and the adsorption mechanism of activated carbons was investigated. The results showed that BET surface area and pore volume of activated carbons were decreased after oxidization process, while acidic functional groups were increased. The surface morphology of oxidized carbons looked clean and eroded which was caused by oxidization of nitric acid. The oxidized carbons showed high adsorption capacity of sodium and formaldehyde, and chemical properties of activated carbon played an important role in adsorption of metal ions and organic pollutants.

  14. Cationization of kappa- and iota-carrageenan--Characterization and properties of amphoteric polysaccharides.

    Science.gov (United States)

    Barahona, Tamara; Prado, Héctor J; Bonelli, Pablo R; Cukierman, Ana L; Fissore, Eliana L; Gerschenson, Lia N; Matulewicz, María C

    2015-08-01

    Commercial kappa- and iota carrageenans were cationized with 3-chloro-2-hydroxypropyltrimethylammonium chloride in aqueous sodium hydroxide solution. For kappa-carrageenan three derivatives with different degrees of substitution were obtained. Native and amphoteric kappa-carrageenans were characterized by NMR and infrared spectroscopy, scanning electron and atomic force microscopy; methanolysis products were studied by electrospray ionization mass spectrometry. Young moduli and the strain at break of films, differential scanning calorimetry, rheological and flocculation behavior were also evaluated; the native and the amphoteric derivatives showed different and interesting properties. Cationization of iota-carrageenan was more difficult, indicating as it was previously observed for agarose, that substitution starts preferentially on the 2-position of 3,6-anhydrogalactose residues; in iota-carrageenan this latter unit is sulfated. PMID:25933524

  15. Synthesis, Characterization, Optical and Electrochemical Properties of Fulleropyrrolidines Containing Trifluoromethyl Group

    Institute of Scientific and Technical Information of China (English)

    李祥子; 余锐; 方舒; 魏先文

    2012-01-01

    Four novel [60]fullerene pyrrolidines containing trifluoromethyl (--CF3) group have been synthesized via 1,3-dipolar cycloaddition reaction, which have been characterized by UV-Vis spectroscopy, fourier transform in- frared spectroscopy, matrix-assisted laser desorption ionization-time of flight mass spectroscopy, and IH, 13C, 19F nuclear magnetic resonance spectrometer (IH NMR, 13C NMR, 19F NMR). Their optical and electrochemical prop- erties have been studied, and the results show that those fulleropyrrolidines containing --CF3 group have good fluo- rescence and electrochemical properties. Compared with C60, they have negative shifts in varying degrees for half-wave potentials, and may have potential applications for photovoltaic conversion materials since their lowest unoccupied molecular orbital (LUMO) levels are close to that of [6,6]-phenyl-C6:butyric acid methyl ester.

  16. Novel axially carborane-cage substituted silicon phthalocyanine photosensitizer; synthesis, characterization and photophysicochemical properties

    Science.gov (United States)

    Atmaca, Göknur Yaşa; Dizman, Cemil; Eren, Tarık; Erdoğmuş, Ali

    2015-02-01

    The novel axially dicarborane substituted silicon (IV) (SiPc-DC) phthalocyanine was synthesized by treating silicon phthalocyanine dichloride SiPc(Cl)2 (SiPc) with o-Carborane monool. The compound was characterized by mass spectrometry, UV-Vis, FT-IR, 1H and 11B Nuclear Magnetic Resonance Spectroscopy (NMR). Spectral, photophysical (fluorescence quantum yield) and photochemical (singlet oxygen (ΦΔ) and photodegradation quantum yield (Φd)) properties of the complex were reported in different solutions (Dimethyl sulfoxide (DMSO), Dimethylformamide (DMF) and Toluene). The results of spectral measurements showed that both SiPc and carborane cage can have potential to be used as sensitizers in photodynamic therapy (PDT) and boron neutron capture therapy (BNCT) by their singlet oxygen efficiencies (ΦΔ = 0.41, 0.39).

  17. Synthesis, characterization and luminescent properties of lanthanide complexes with a novel multipodal ligand

    Science.gov (United States)

    Yan, Zhen-Zhong; Hou, Na; Wang, Cong-Min

    2015-02-01

    Solid complexes of lanthanide nitrates with an novel multipodal ligand, 1,2,4,5-tetramethyl-3,6-bis{N,N-bis[((2‧-furfurylaminoformyl)phenoxyl)ethyl]-aminomethyl}-benzene (L) have been synthesized and characterized by elemental analysis, infrared spectra and molar conductivity measurements. At the same time, the luminescent properties of the Sm(III), Eu(III), Tb(III) and Dy(III) nitrate complexes in solid state were investigated. Under the excitation of UV light, these complexes exhibited characteristic emission of central metal ions. The lowest triplet state energy level of the ligand indicates that the triplet state energy level (T1) of the ligand matches better the resonance level of Tb(III) than other lanthanide ions.

  18. Quantitative Characterization of the Microstructure and Transport Properties of Biopolymer Networks

    CERN Document Server

    Jiao, Yang

    2012-01-01

    Biopolymer networks are of fundamental importance to many biological processes in normal and tumorous tissues. In this paper, we employ the panoply of theoretical and simulation techniques developed for characterizing heterogeneous materials to quantify the microstructure and effective diffusive transport properties (diffusion coefficient $D_e$ and mean survival time $\\tau$) of collagen type I networks at various collagen concentrations. In particular, we compute the pore-size probability density function $P(\\delta)$ for the networks and present a variety of analytical estimates of the effective diffusion coefficient $D_e$ for finite-sized diffusing particles. The Hashin-Strikman upper bound on the effective diffusion coefficient $D_e$ and the pore-size lower bound on the mean survival time $\\tau$ are used as benchmarks to test our analytical approximations and numerical results. Moreover, we generalize the efficient first-passage-time techniques for Brownian-motion simulations in suspensions of spheres to th...

  19. Novel axially carborane-cage substituted silicon phthalocyanine photosensitizer; synthesis, characterization and photophysicochemical properties.

    Science.gov (United States)

    Atmaca, Göknur Yaşa; Dizman, Cemil; Eren, Tarık; Erdoğmuş, Ali

    2015-02-25

    The novel axially dicarborane substituted silicon (IV) (SiPc-DC) phthalocyanine was synthesized by treating silicon phthalocyanine dichloride SiPc(Cl)2 (SiPc) with o-Carborane monool. The compound was characterized by mass spectrometry, UV-Vis, FT-IR, (1)H and (11)B Nuclear Magnetic Resonance Spectroscopy (NMR). Spectral, photophysical (fluorescence quantum yield) and photochemical (singlet oxygen (ΦΔ) and photodegradation quantum yield (Φd)) properties of the complex were reported in different solutions (Dimethyl sulfoxide (DMSO), Dimethylformamide (DMF) and Toluene). The results of spectral measurements showed that both SiPc and carborane cage can have potential to be used as sensitizers in photodynamic therapy (PDT) and boron neutron capture therapy (BNCT) by their singlet oxygen efficiencies (ΦΔ=0.41, 0.39). PMID:25222320

  20. Zinc oxide nanoparticle-coated films: fabrication, characterization, and antibacterial properties

    International Nuclear Information System (INIS)

    In this article, novel antibacterial PVC-based films coated with ZnO nanoparticles (NPs) were fabricated, characterized, and studied for their antibacterial properties. It was shown that the ZnO NPs were coated on the surface of the PVC films uniformly and that the coating process did not affect the size and shape of the NPs on the surface of PVC films. Films coated with concentrations of either 0.2 or 0.075 g/L of ZnO NPs exhibited antibacterial activity against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria, but exhibited no antifungal activity against Aspergillus flavus and Penicillium citrinum. Smaller particles (100 nm) exhibited more potent antibacterial activity than larger particles (1000 nm). All ZnO-coated films maintained antibacterial activity after 30 days in water

  1. Electrostatic Properties and Characterization of Textile Materials Affected by Ion Flux

    Directory of Open Access Journals (Sweden)

    Pranas Juozas ŽILINSKAS

    2013-03-01

    Full Text Available This work analyzes the opportunities of wider characterization of textile materials, fabrics, upholstery fabrics, fibers, yarns or others, which may accumulate electric charge. A non-contact way for electrostatic properties measurement based on affecting those materials by ions with positive or negative charge is described. The method allows to measure simultaneously the time dependences of the surface voltage and the electric charge during the charging process and the time dependences of the surface voltage during the discharging process. From the measured dependencies the following set of parameters was measured or calculated: the surface voltage limiting value, the surface voltage semi-decay time, the maximum deposited charge, the layer capacitance, the energy of the accumulated charge and others. The surface voltage distribution measurement method when the investigated textile material is affected by ion flux was also described. To verify the applicability of the proposed methods for characterization of textile materials in order to determine the above-mentioned parameters of cotton, linen, wool, viscose, acetate, polyester, polyester coated with polytetrafluoroethylene, a series of experiments were performed. The surface voltage distribution measurement method based on affecting textile materials by ions with positive charge was described and a surface voltage distribution of a polyester-cotton upholstery fabric produced by a Jacquard mechanism was presented. The performed experiments demonstrate the possibilities of method application for comparison of the electrostatic properties of different textile materials used for the same tasks or the same materials produced by different technological processes.DOI: http://dx.doi.org/10.5755/j01.ms.19.1.3828

  2. Physicochemical characterization and evaluation of suspending properties of arabinoxylan from Ispaghula (Plantago ovata) husk.

    Science.gov (United States)

    Bashir, Sajid; Erum, Alia; Saghir, Shazia; Tulain, Umme Ruqia; Rashid, Ayesha

    2014-11-01

    The purpose of this study is to evaluate the use of arabinoxylan as potential suspending agent, an effective alternative to commercially used excipients for the preparation of pharmaceutical suspensions. Alkali extraction was done to separate arabinoxylan from ispaghula (Plantago ovata) seed husk by alkali extraction its physicochemical characterization was done and the suspending properties of arabinoxylan isolated were evaluated comparatively with those of bentonite at different concentration ranges of 0.125,0.25,0.5 and 1% in Zinc oxide suspension. The parameters employed for evaluation were sedimentation volume, degree of flocculation, flow rate, density, pH, redispersibility, microbiological evaluation and particle size analysis. Physicochemical characterization of arabinoxylan indicates its suitability as excipient as it has fair flow properties, low moisture content and almost neutral pH. Arabinoxylan at low conc. 0.125% showed sedimentation volume comparable to commercially used suspending agents such as bentonite 1% while suspensions containing higher concentrations such as 0.25% (sedimentation volume 92%), 0.5% (sedimentation volume 94%) and 1% conc. (sedimentation volume 98%) of arabinoxylan remained almost completely suspended during study period of 7 days. Formulations containing 0.125% and 0.25% arabinoxylan as suspending agents are easily redispersible as compared to bentonite containing formulation while formulation containing 0.5% arabinoxylan are moderately redispersible while formulation containing 1% suspending agent gel upon storage and was not redispersible. Furthermore arabinoxylan produces stable, highly flocculated suspension, which fulfilled microbiological, and particle size specifications, however the formulations containing higher arabinoxylan 1% concentration gel upon storage. So it is concluded that arabinoxylan could be used as effective suspending agent at low concentrations in Zinc oxide suspension. PMID:25362588

  3. Ultrasonic Characterization of Fiber-Matrix Interphasial Properties and Damage in High-Temperature Composites

    Science.gov (United States)

    Chu, Ya-Cherng

    This study addresses ultrasonic characterization of fiber-matrix interphasial properties and damage in high -temperature composites. To accomplish this, experimental techniques for measurements of ultrasonic phase velocities and methodology for calculation of composite elastic moduli from velocity data are first developed and applied to unidirectional ceramic and intermetallic matrix composites. It is shown that computational error in the composite moduli is comparable to experimental error in the velocity data. For cross -ply composites, a novel method for determination of lamina elastic moduli from measurements on a (0/90) _ {s} composite is developed and validated experimentally. Second, a method to determine the elastic moduli of interphasial layers in high-temperature composites from the measured composite moduli is developed and applied to characterization of 3-μm thick carbon interphasial layers in ceramic and intermetallic matrix composites. Third, the techniques developed are used for assessment of oxidation and fatigue damage in ceramic and metal matrix composites. It is shown that ultrasonic phase velocities are very sensitive to damage and can effectively quantify damage severity. Appropriate models are applied to describe the effect of damage on the measured ultrasonic data, and they show reasonable agreement with experiments.

  4. Exchange coupled L10-FePt/fcc-FePt nanomagnets: Synthesis, characterization and magnetic properties

    Science.gov (United States)

    Srivastava, Sachchidanand; Gajbhiye, Namdeo S.

    2016-03-01

    We report synthesis, characterization and magnetic properties of exchange-coupled L10-FePt/fcc-FePt nanomagnets. Structural and morphological characterization of exchange-coupled L10-FePt/fcc-FePt was carried out by powder X-ray diffraction, Mössbauer spectroscopy and transmission electron microscopy. Rietveld refinement of powder X-ray diffraction pattern has been used to quantify L10-FePt and fcc-FePt phases present in samples. Room temperature Mössbauer spectroscopy showed sextets of both L10-FePt and fcc-FePt phases with their respective hyperfine interaction parameters. Transmission electron microscopic (TEM and HRTEM) images confirmed nanocrystalline nature of exchange-coupled nanomagnets with particle size ranges from 15 nm to 50 nm after annealing for different time at 700 °C. Room temperature magnetic studies showed ferromagnetic nature of nanomagnets and maximum energy product (BH)max~10.92 MGOe was obtained for sample containing 89.0% volume fraction of L10-FePt phase.

  5. Optically active substituted polyacetylene@carbon nanotube hybrids: Preparation, characterization and infrared emissivity property study

    Energy Technology Data Exchange (ETDEWEB)

    Bu, Xiaohai; Zhou, Yuming, E-mail: ymzhou@seu.edu.cn; Zhang, Tao; Wang, Yongjuan; Zhang, Zewu; He, Man

    2014-08-15

    Optically active substituted polyacetylene@multiwalled carbon nanotubes (SPA@MWCNTs) nanohybrids were fabricated by wrapping helical SPA copolymers onto the surface of modified nanotubes through ester bonding linkage. SPA copolymer based on chiral phenylalanine and serine was pre-polymerized by a rhodium zwitterion catalyst in THF, and evidently proved to possess strong optical activity and adopt a predominately one-handed helical conformation. Various characterizations including Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and transmission electron microscopy (TEM) demonstrated that the SPA had been covalently grafted onto the nanotubes without destroying their original graphite structure. The wrapped SPA was found to exhibit an enhancement in thermal stability and still maintained considerable optical activity after grafting. The infrared emissivity property of the nanohybrids at 8–14 μm was investigated in addition. The results indicated that the SPA@MWCNTs hybrid matrix could possess a much lower infrared emissivity value (ε=0.707) than raw MWCNTs, which might be due to synergistic effect of the unique helical conformation of optically active SPA and strengthened interfacial interaction between the organic polymers and inorganic nanoparticles. - Graphical abstract: Optically active SPA@MWCNTs nanohybrids with low infrared emissivity. - Highlights: • Synthesis of optically active SPA copolymer derived from serine and phenylalanine. • Preparation and characterization of optically active SPA@MWCNTs nanohybrids. • Application study of the SPA@MWCNTs nanohybrids (ε=0.707) in lowering the infrared emissivity.

  6. Optically active substituted polyacetylene@carbon nanotube hybrids: Preparation, characterization and infrared emissivity property study

    International Nuclear Information System (INIS)

    Optically active substituted polyacetylene@multiwalled carbon nanotubes (SPA@MWCNTs) nanohybrids were fabricated by wrapping helical SPA copolymers onto the surface of modified nanotubes through ester bonding linkage. SPA copolymer based on chiral phenylalanine and serine was pre-polymerized by a rhodium zwitterion catalyst in THF, and evidently proved to possess strong optical activity and adopt a predominately one-handed helical conformation. Various characterizations including Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and transmission electron microscopy (TEM) demonstrated that the SPA had been covalently grafted onto the nanotubes without destroying their original graphite structure. The wrapped SPA was found to exhibit an enhancement in thermal stability and still maintained considerable optical activity after grafting. The infrared emissivity property of the nanohybrids at 8–14 μm was investigated in addition. The results indicated that the SPA@MWCNTs hybrid matrix could possess a much lower infrared emissivity value (ε=0.707) than raw MWCNTs, which might be due to synergistic effect of the unique helical conformation of optically active SPA and strengthened interfacial interaction between the organic polymers and inorganic nanoparticles. - Graphical abstract: Optically active SPA@MWCNTs nanohybrids with low infrared emissivity. - Highlights: • Synthesis of optically active SPA copolymer derived from serine and phenylalanine. • Preparation and characterization of optically active SPA@MWCNTs nanohybrids. • Application study of the SPA@MWCNTs nanohybrids (ε=0.707) in lowering the infrared emissivity

  7. Structure Characterization and Properties of Metal-Surfactant Complexes Dispersed in Organic Solvents.

    Science.gov (United States)

    de la Iglesia, Pablo; Jaeger, Vance W; Xi, Yuyin; Pfaendtner, Jim; Pozzo, Lilo D

    2015-08-25

    This work describes the synthesis and characterization of metal-surfactant complexes. Dioctyl sulfosuccinate and dodecylbenzenesulfonate are associated with multivalent aluminum, iron, and vanadium ions using an ion exchange reaction. The metal complexes are dispersible in various organic solvents. In solvents with low polarity, the complexes form "inverse" macromolecular structures with multiple metal ions. In contrast, in alcohols, the complex size is reduced, showing a more disperse conformation. The metal and surfactant ions are still strongly bonded to each other in all the solvents probed. Small-angle X-ray and neutron scattering (SAXS and SANS) are used to characterize the structures. Simultaneous fitting of neutron and X-ray scattering spectra is performed in order to obtain an accurate description of the system. Scattering results are also validated by performing molecular dynamics (MD) simulations. The conductive and electrochemical properties of the complexes in solution are also evaluated. The dispersion of metal-organic complexes significantly increases electric conductivity, and some metal ions in the core of the complexes are shown to be electrochemically active in apolar solvents. PMID:26212253

  8. Characterization and luminescence properties of Sr3Gd): Sm3+ orange-red phosphor

    Science.gov (United States)

    Yang, Zaifa; Xu, Denghui; Sun, Jiayue; Sun, Yumei; Du, Haiyan

    2015-10-01

    Reddish-orange emitting phosphors, Sr3Gd): Sm3+, were successfully synthesized by a conventional solid-state reaction. The crystal structure of the phosphors was characterized by x-ray diffraction. The excitation spectra and emission spectra were utilized to characterize the luminescence properties of the as-prepared phosphors. The results show that the phosphor consisted of some sharp emission peaks of Sm3+ ions centered at 564, 600, 647, and 707 nm, respectively. The critical distance of Sr3Gd0.93): 0.07Sm3+ was calculated to be 19.18 Å and the lifetime value of the sample was 1.63 ms. The band gap of Sr3Gd) was estimated to be about 2.74 eV from the diffuse reflection spectrum. The optimum doping concentration is 7 mol. % and the quenching occurs via dipole-dipole interaction according to Dexter's theory. The Commission Internationale de L'Eclairage value of Sr3Gd): Sm3+ phosphors presented that it has high color purity. These results indicated that the Sr3Gd): Sm3+ may be a promising reddish-orange emitting phosphor for cost-effective near ultraviolet white light-emitting diodes.

  9. Regional characterization of hydraulic properties of rock using well test data

    International Nuclear Information System (INIS)

    This study was aimed at investigating the possible use of data from the SGU well archive for characterization of the hydraulic properties of the crystalline basement of Sweden at a regional scale. Two areas studied as possible candidates for a radioactive waste repository were selected. The SGU well data and the hydraulic conductivity data evaluated from packer tests in boreholes at the sites were characterized statistically also considering possible spatial dependence. The two types of data were compared and the correlation between the data sets was investigated. This part of the study considered the uppermost 100 m of the packer test data, which is the approximate depth range covered by the SGU data. In a second part of the work the packer test data from the two study areas were analyzed in terms of possible depth trends. The exploratory statistical analyses suggested that the SGU data are useful for estimations of hydrogeological parameters for areas of different geologic settings. The geostatistical analysis provided further understanding of the spatial behaviour of the studied parameters. The analysis of depth dependence indicates that at both sites there is a layer of higher hydraulic conductivity close to the surface. Within these layers, about 200 and 280 m thick, resp., the conductivity decreases with increasing depth. At larger depths however, the decrease with depth is very slow or negligible. It was found that the scatter in the measured hydraulic conductivity data is very large compared to differences between the depth functions tested

  10. TDR-EC: A Rapid Subsurface Characterization of Particle Size & Hydrologic Properties

    Science.gov (United States)

    Jones, C. A.; Schaap, M. G.

    2011-12-01

    Time-domain reflectometry (TDR) is a geophysical tool used in the field and laboratory to determine soil moisture, bulk soil electric conductivity (EC). We employ this tool in many ways to understand temporal and spatial soil dynamics in a small catchment. Several hundred sites within this catchment, located in the Valles Caldera National Preserve, were surveyed using TDR with the intention of characterizing the spatial distribution of soil properties. Data was collected a few weeks after the snowmelt, when we assumed the soil to be at field capacity and therefore, the relationship between soil texture and moisture content is strongest. Laser diffraction particle size analyses of the soils sampled in this survey demonstrated that bulk soil EC correlates very strongly to clay and sand fractions. This relationship provides us with an estimate of soil texture once the difference between estimated clay and sand is calculated. A pedo-transfer function, Rosetta, is used to approximate saturated hydraulic conductivity, Ksat. In order to test the effectiveness of estimating Ksat using this method, ring infiltrometers were used at numerous sample locations. To further investigate the relationship between bulk soil EC and clay, the same type of survey in two catchments of different parent material was completed earlier this year Temporal characterization is achieved with the use of data from soil pits instrumented at several depths with sensors recording, water content, EC, temperature, and matric potential at 10 minute intervals. Preliminary results from HYDRUS 1-D will guide us in determining whether or not a 2 or 3-D model is necessary to characterize subsurface dynamics.

  11. Synthesis, characterization and magnetic properties of polyaniline/-Fe2O3 composites

    Indian Academy of Sciences (India)

    Syed Khasim; S C Raghavendra; M Revanasiddappa; K C Sajjan; Mohana Lakshmi; Muhammad Faisal

    2011-12-01

    Conducting polyaniline/-Fe2O3 (PANI/FE) composites have been synthesized using an in situ deposition technique by placing fine-graded -Fe2O3 in a polymerization mixture of aniline. The composites are characterized by using scanning electron microscopy (SEM), X-ray diffraction (XRD) and infrared (IR) spectroscopy. The electrical properties such as d.c. and a.c. conductivities are studied by sandwitching the pellets of these composites between the silver electrodes. It is observed that the conductivity increases up to a composition of 20 wt.% of -Fe2O3 in polyaniline and decreases thereafter. The initial increase in conductivity is attributed to the extended chain length of polyaniline, where polarons possess sufficient energy to hop between favourable sites. Beyond 20 wt.% of -Fe2O3 in polyaniline, the blocking of charge carrier hop occurs, reducing conductivity values. The magnetic properties such as hysteresis characteristics and normalized a.c. susceptibility are also measured, which show a strong dependence on content of -Fe2O3 in polyaniline. Because of superparamagnetic behaviour of these composites, they may find extensive technological applications, especially for absorbing and shielding applications in microwave frequencies.

  12. Preparation, Characterization, and Enhanced Thermal and Mechanical Properties of Epoxy-Titania Composites

    Directory of Open Access Journals (Sweden)

    Zakya Rubab

    2014-01-01

    Full Text Available This paper presents the synthesis and thermal and mechanical properties of epoxy-titania composites. First, submicron titania particles are prepared via surfactant-free sol-gel method using TiCl4 as precursor. These particles are subsequently used as inorganic fillers (or reinforcement for thermally cured epoxy polymers. Epoxy-titania composites are prepared via mechanical mixing of titania particles with liquid epoxy resin and subsequently curing the mixture with an aliphatic diamine. The amount of titania particles integrated into epoxy matrix is varied between 2.5 and 10.0 wt.% to investigate the effect of sub-micron titania particles on thermal and mechanical properties of epoxy-titania composites. These composites are characterized by X-ray photoelectron (XPS spectroscopy, scanning electron microscopy (SEM, differential scanning calorimetry (DSC, thermogravimetric (TG, and mechanical analyses. It is found that sub-micron titania particles significantly enhance the glass transition temperature (>6.7%, thermal oxidative stability (>12.0%, tensile strength (>21.8%, and Young’s modulus (>16.8% of epoxy polymers. Epoxy-titania composites with 5.0 wt.% sub-micron titania particles perform best at elevated temperatures as well as under high stress.

  13. Growth, Characterization, and Electrochemical Properties of Doped n-type KTaO3 Photoanodes

    Energy Technology Data Exchange (ETDEWEB)

    Paulauskas, Irene E [ORNL; Katz, J. E. [Beckman Institute and Kavli Nanoscience Institute, Division of Chemistry and Che; Lewis, N. [California Institute of Technology, Pasadena; Boatner, Lynn A [ORNL; Brown, G. M. [Oak Ridge National Laboratory (ORNL)

    2009-01-01

    The effects of compositionally induced changes on the semiconducting properties, optical response, chemical stability, and overall performance of KTaO3 photo-anodes in photoelectrochemical cells have been investigated. Single crystals of n-type Ca- and Ba-doped KTaO3 with carrier concentrations ranging from 0.45 - 11.5 x 1019 cm-3 were grown and characterized as photoanodes for hydrogen production in basic aqueous electrolytes. The photoelectrochemical properties of the crystals, including the photocurrent, photovoltage, and flat-band potential in contact with 8.5 M NaOH(aq) were relatively independent of whether Ca or Ba was used to produce the semiconducting form of KTaO3. All of the Ca- or Ba- doped KTaO3 single crystal photoanodes were chemically stable in the electrolyte; and based on the open-circuit potential and the band-edge positions, they were capable of unassisted photochemical H2 and O2 evolution from H2O. The minority carrier diffusion lengths values were small and comparable to the depletion region width. Photoanodic currents were only observed for photo-anode illumination with light above the band gap (i.e., < 340 nm). The maximum external quantum yield occurred at = 1 nm (4.85 eV), and the depletion width plus the minority carrier diffusion length ranged from 20 to 65 nm for the various KTaO3-based photoanode materials.

  14. New bithiophene-containing electroluminescent polymer: Synthesis, characterization, optical and electrical properties

    Science.gov (United States)

    Jaballah, Nejmeddine; Chemli, Mejed; Fave, Jean-Louis; Majdoub, Mustapha

    2015-12-01

    A semi-conducting polymer, P-DSBT, based on distyryl-bithiophene π-conjugated sequences has been synthesized and characterized. The macromolecular material was soluble in volatile solvents and showed a good film quality; it exhibited an amorphous morphology with relatively high glass transition temperature. The absorption and photoluminescence properties of the polymer were studied in solution and as thin solid film, which showed an optical gap of 2.6 eV. The HOMO/LUMO energy levels were evaluated by cyclic voltammetry measurements and indicate a p-type semi-conducting material. The electrical properties of P-DSBT were investigated by the current-tension characteristic and modeled by the current space-charge-limited (SCLC) mechanism; charge carrier mobility higher than 10-6 cm2 V-1 s-1 was evaluated. A yellow-green electroluminescence was evidenced in a multilayer organic light-emitting diode with an [ITO/PEDOT:PPS/P-DSBT/BCP/Al] configuration.

  15. Characterization and electrocatalytic properties of sonochemical synthesized PdAg nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Godinez-Garcia, Andres, E-mail: agodinez@qro.cinvestav.mx [Depto. Materiales, Centro de Investigacion y de Estudios Avanzados del IPN, Libramiento norponiente 2000, Fracc. Real de Juriquilla, C.P. 76230 Santiago de Queretaro, Qro. (Mexico); Perez-Robles, Juan Francisco [Depto. Materiales, Centro de Investigacion y de Estudios Avanzados del IPN, Libramiento norponiente 2000, Fracc. Real de Juriquilla, C.P. 76230 Santiago de Queretaro, Qro. (Mexico); Martinez-Tejada, Hader Vladimir [Grupo de Energia y Termodinamica, Universidad Pontificia Bolivariana, Medellin, Antioquia C.P. 050031 (Colombia); Solorza-Feria, Omar [Depto. Quimica, CINVESTAV-IPN, Av. IPN 2508, A. P. 14-740, 07360 D.F. Mexico (Mexico)

    2012-06-15

    High intensity ultrasound was used in the synthesis of PdAg nanoparticles. PdAg nanoparticles were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS), scanning transmission electron microscopy (STEM) and high-resolution transmission electron microscopy (HRTEM). Catalytic properties for oxygen reduction reaction (ORR) were determined by electrochemical techniques of cyclic voltammetry (CV) and thin-film rotating disk electrode (TF-RDE). Finally the electrocatalyst was tested as a cathode in a single polymer electrolyte membrane fuel cell (PEMFC). Sonochemical synthesis (SS) decreased the overpotential required for the ORR and increased the double-layer capacitance (DLC) respect to the sodium borohydride reduction method due to a better distribution on vulcan carbon support. The electrocatalytic activity of the nanometric bimetallic electrocatalyst for the ORR in acid media showed a favorable multielectron charge transfer process (n = 4e{sup -}) to water formation. The performance of the membrane electrode assembly (MEA) prepared with dispersed PdAg/C as a cathode catalyst in a single PEMFC is lower in comparison to platinum. - Highlights: Black-Right-Pointing-Pointer Sonochemical synthesized PdAg nanoparticles supported on carbon were produced. Black-Right-Pointing-Pointer The material showed catalytic properties for the oxygen reduction reaction (ORR). Black-Right-Pointing-Pointer The ORR favored the pathway to water formation.

  16. Characterization and electrocatalytic properties of sonochemical synthesized PdAg nanoparticles

    International Nuclear Information System (INIS)

    High intensity ultrasound was used in the synthesis of PdAg nanoparticles. PdAg nanoparticles were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS), scanning transmission electron microscopy (STEM) and high-resolution transmission electron microscopy (HRTEM). Catalytic properties for oxygen reduction reaction (ORR) were determined by electrochemical techniques of cyclic voltammetry (CV) and thin-film rotating disk electrode (TF-RDE). Finally the electrocatalyst was tested as a cathode in a single polymer electrolyte membrane fuel cell (PEMFC). Sonochemical synthesis (SS) decreased the overpotential required for the ORR and increased the double-layer capacitance (DLC) respect to the sodium borohydride reduction method due to a better distribution on vulcan carbon support. The electrocatalytic activity of the nanometric bimetallic electrocatalyst for the ORR in acid media showed a favorable multielectron charge transfer process (n = 4e−) to water formation. The performance of the membrane electrode assembly (MEA) prepared with dispersed PdAg/C as a cathode catalyst in a single PEMFC is lower in comparison to platinum. - Highlights: ► Sonochemical synthesized PdAg nanoparticles supported on carbon were produced. ► The material showed catalytic properties for the oxygen reduction reaction (ORR). ► The ORR favored the pathway to water formation.

  17. Charge Variants of an Avastin Biosimilar Isolation, Characterization, In Vitro Properties and Pharmacokinetics in Rat.

    Directory of Open Access Journals (Sweden)

    Yan-Yan Zhao

    Full Text Available The similarity between a proposed biosimilar product and the reference product can be affected by many factors. This study is designed to examine whether any subtle difference in the distribution of the charge variants of an Avastin biosimilar can affect its in vitro potency and in vivo PK. Here, the acidic, basic and main peak fractions of a biosimilar product were isolated using high-performance cation-exchange chromatography and were subjected to various studies to compare their in vitro properties and in vivo PK profile. A serial of analytical methods, including size exclusion chromatography (SEC, imaged capillary isoelectric focusing (icIEF capillary zone electrophoresis (CZE and cation-exchange chromatography (CEX-HPLC were also used to characterize the isolated charge variants. The kinetics constant was measured using a Biacore X100 system. The study indicates the biosimilar product has a high similarity with avastin in physicochemical properties. The potency in vitro and PK profile in rat of charge variants and biosimilar product are consistent with avastin.

  18. Characterization of biomechanical properties of aged human and ovine mitral valve chordae tendineae.

    Science.gov (United States)

    Zuo, Keping; Pham, Thuy; Li, Kewei; Martin, Caitlin; He, Zhaoming; Sun, Wei

    2016-09-01

    The mitral valve (MV) is a highly complex cardiac valve consisting of an annulus, anterior and posterior leaflets, chordae tendineae (chords) and two papillary muscles. The chordae tendineae mechanics play a pivotal role in proper MV function: the chords help maintain proper leaflet coaptation and rupture of the chordae tendineae due to disease or aging can lead to mitral valve insufficiency. Therefore, the aim of this study was to characterize the mechanical properties of aged human and ovine mitral chordae tendineae. The human and ovine chordal specimens were categorized by insertion location (i.e., marginal, basal and strut) and leaflet type (i.e., anterior and posterior). The results show that human and ovine chords of differing types vary largely in size but do not have significantly different elastic and failure properties. The excess fibrous tissue layers surrounding the central core of human chords added thickness to the chords but did not contribute to the overall strength of the chords. In general, the thinner marginal chords were stiffer than the thicker basal and strut chords, and the anterior chords were stiffer and weaker than the posterior chords. The human chords of all types were significantly stiffer than the corresponding ovine chords and exhibited much lower failure strains. These findings can be explained by the diminished crimp pattern of collagen fibers of the human mitral chords observed histologically. Moreover, the mechanical testing data was modeled with the nonlinear hyperelastic Ogden strain energy function to facilitate accurate computational modeling of the human MV. PMID:27315372

  19. Synthesis and characterization of vegetable oil derived esters: evaluation for their diesel additive properties.

    Science.gov (United States)

    Dmytryshyn, S L; Dalai, A K; Chaudhari, S T; Mishra, H K; Reaney, M J

    2004-03-01

    Trans-esterification of four vegetable oils; canola oil, greenseed canola oil from heat-damaged seeds, processed waste fryer grease and unprocessed waste fryer grease, was carried out using methanol, and KOH as catalyst. The methyl esters of the corresponding oils were separated from the crude glycerol, purified, and characterized by various methods to evaluate their densities, viscosities, iodine values, acid numbers, cloud points, pour points and gross heat of combustion, fatty acid and lipid compositions, lubricity properties, and thermal properties. The fatty acid composition suggests that 80-85% of the ester was from unsaturated acids. Substantial decrease in density and viscosity of the methyl esters compared to their corresponding oils suggested that the oils were in their mono or di glyceride form. The lubricity of the methyl esters, when blended at 1 vol% treat rate with ISOPAR M reference fuel, showed that the canola methyl ester enhanced the fuel's lubricity number. From the analyses performed, it was determined that the ester with the most potential for being an additive or a substitute for diesel fuel is the canola methyl ester, whose physical and chemical characteristics are similar to diesel fuel. PMID:14643986

  20. Synthesis, Characterization, and Microwave-Absorbing Properties of Polypyrrole/MnFe2O4 Nanocomposite

    Directory of Open Access Journals (Sweden)

    Seyed Hossein Hosseini

    2012-01-01

    Full Text Available Conductive polypyrrole (PPy-manganese ferrite (MnFe2O4 nanocomposites with core-shell structure were synthesized by in situ polymerization in the presence of dodecyl benzene sulfonic acid (DBSA as the surfactant and dopant and iron chloride (FeCl3 as the oxidant. The structure and magnetic properties of manganese ferrite nanoparticles were measured by using powder X-ray diffraction (XRD and vibrating sample magnetometer (VSM, respectively. Its morphology, microstructure, and DC conductivity of the nanocomposite were characterized by scanning electron microscopy (SEM, Fourier transform infrared spectroscopy (FTIR, and four-wire technique, respectively. The microwave-absorbing properties of the nanocomposite powders dispersing in resin acrylic coating with the coating thickness of 1.5 mm were investigated by using vector network analyzers in the frequency range of 8–12 GHz. A minimum reflection loss of −12 dB was observed at 11.3 GHz.

  1. Thermal property characterization of fine fibers by the 3-omega technique

    International Nuclear Information System (INIS)

    The 3 omega method is one of few reliable measurement techniques for thermal characterization of micro to nanoscale suspended wires or fibers and has been applied for measurements of carbon nanotubes and silicon nanowires. However, the models described in the past were either complicated for analysis or simplified from a more complete solution. In addition, the past models cannot be implemented directly when using a more reliable measurement configuration with a Wheatstone bridge. In this work, a simpler, explicit model, is developed to describe the heat transfer process through a suspended wire for measurement of its thermal properties. Generic trends and values of the 3ω harmonic voltage amplitude and phase responses clearly indicate the frequency limits for thermal conductivity and heat capacity determination and ideal conditions for thermal diffusivity estimation. Based on a sensitivity analysis, these limits are confirmed and appropriate frequency ranges for thermal conductivity and diffusivity are recommended. Radiation influence on the measurement results is quantified and correlated to a dimensionless radiation parameter. Two methods are presented to determine sample thermal properties independent of lateral heat losses and validated by numerical experiments using COMSOL. Uncertainty analysis was also derived by Taylor series expansion with calculated parameter sensitivities. - Highlights: • An improved model for suspended wire 3 omega measurement. • Quantification on the radiation induced measurement error. • Numerical simulation validating the improved model. • Sensitivity analysis to find measurement range minimizing uncertainty

  2. Charge Variants of an Avastin Biosimilar Isolation, Characterization, In Vitro Properties and Pharmacokinetics in Rat.

    Science.gov (United States)

    Zhao, Yan-Yan; Wang, Ning; Liu, Wan-Hui; Tao, Wen-Jie; Liu, Li-Li; Shen, Zhen-Duo

    2016-01-01

    The similarity between a proposed biosimilar product and the reference product can be affected by many factors. This study is designed to examine whether any subtle difference in the distribution of the charge variants of an Avastin biosimilar can affect its in vitro potency and in vivo PK. Here, the acidic, basic and main peak fractions of a biosimilar product were isolated using high-performance cation-exchange chromatography and were subjected to various studies to compare their in vitro properties and in vivo PK profile. A serial of analytical methods, including size exclusion chromatography (SEC), imaged capillary isoelectric focusing (icIEF) capillary zone electrophoresis (CZE) and cation-exchange chromatography (CEX-HPLC) were also used to characterize the isolated charge variants. The kinetics constant was measured using a Biacore X100 system. The study indicates the biosimilar product has a high similarity with avastin in physicochemical properties. The potency in vitro and PK profile in rat of charge variants and biosimilar product are consistent with avastin. PMID:26987122

  3. Characterization of macroscopic properties and crystalline defects in neutron-irradiated silicon carbide

    International Nuclear Information System (INIS)

    Length change, mechanical properties, helium release behavior, ESR observation and microstructure of neutron-irradiated silicon carbide (SiC) were investigated. Changes in those properties due to annealing were also measured to clarify the relationship between crystalline defects induced by neutron irradiation and macroscopic properties. The effects of external stress on defect annihilation and bubble swelling during annealing of neutron-irradiated specimens were investigated. From those experiments, it is clarified that the decrease in length by annealing below 1300 degC was not affected by the external stress. However, annealing above 1300 degC led to an increase in length in B-containing SiC, and the compressive stress retarded the expansion along the loading direction. The helium release behavior of neutron-irradiated SiC containing B was observed and it was clarified that the helium release rate of ceramic and its powder was different from each other. Defects characterization was carried out by ESR measurement and high-resolution electron microscopy. It was indicated that the vacancies with unpaired electron detected by ESR selectively disappear at lower temperature than those detected by a macroscopic length measurement. High-resolution electron microscopy revealed that very small interstitial type Flank loops lying on {111}, having a Burgers vector b=1/3, were formed in β-SiC heavily-neutron-irradiated in a fast reactor. Defect nuclei, a few nanometer in diameter, in hexagonal α-SiC were induced by lower doses in a thermal reactor. They are on the (0001) basal plane and have a Burgers vector b=1/6 [0001]. (J.P.N.)

  4. Characterization of differential properties of rabbit tendon stem cells and tenocytes

    Directory of Open Access Journals (Sweden)

    Wang James

    2010-01-01

    Full Text Available Abstract Background Tendons are traditionally thought to consist of tenocytes only, the resident cells of tendons; however, a recent study has demonstrated that human and mouse tendons also contain stem cells, referred to as tendon stem/progenitor cells (TSCs. However, the differential properties of TSCs and tenocytes remain largely undefined. This study aims to characterize the properties of these tendon cells derived from rabbits. Methods TSCs and tenocytes were isolated from patellar and Achilles tendons of rabbits. The differentiation potential and cell marker expression of the two types of cells were examined using histochemical, immunohistochemical, and qRT-PCR analysis as well as in vivo implantation. In addition, morphology, colony formation, and proliferation of TSCs and tenocytes were also compared. Results It was found that TSCs were able to differentiate into adipocytes, chondrocytes, and osteocytes in vitro, and form tendon-like, cartilage-like, and bone-like tissues in vivo. In contrast, tenocytes had little such differentiation potential. Moreover, TSCs expressed the stem cell markers Oct-4, SSEA-4, and nucleostemin, whereas tenocytes expressed none of these markers. Morphologically, TSCs possessed smaller cell bodies and larger nuclei than ordinary tenocytes and had cobblestone-like morphology in confluent culture whereas tenocytes were highly elongated. TSCs also proliferated more quickly than tenocytes in culture. Additionally, TSCs from patellar tendons formed more numerous and larger colonies and proliferated more rapidly than TSCs from Achilles tendons. Conclusions TSCs exhibit distinct properties compared to tenocytes, including differences in cell marker expression, proliferative and differentiation potential, and cell morphology in culture. Future research should investigate the mechanobiology of TSCs and explore the possibility of using TSCs to more effectively repair or regenerate injured tendons.

  5. Synthesis, characterization, growth mechanism, photoluminescence and field emission properties of novel dandelion-like gallium nitride

    International Nuclear Information System (INIS)

    Dandelion-like gallium nitride (GaN) microstructures were successfully synthesized via Ni catalyst assisted chemical vapor deposition method at 1200 deg. C under NH3 atmosphere by pre-treating precursors with aqueous ammonia. The as-synthesized product was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). X-ray diffraction analysis revealed that as-synthesized dandelion-like GaN was pure and has hexagonal wurtzite structure. SEM results showed that the size of the dandelion-like GaN structure was in the range of 30-60 μm. Dandelion-like GaN microstructures exhibited reasonable field emission properties with the turn-on field of 9.65 V μm-1 (0.01 mA cm-2) and threshold field of 11.35 V μm-1 (1 mA cm-2) which is sufficient for applications of electron emission devices, field emission displays and vacuum micro electronic devices. Optical properties were studied at room temperature by using fluorescence spectrophotometer. Photoluminescence (PL) measurements of dandelion-like GaN showed a strong near-band-edge emission at 370.2 nm (3.35 eV) with blue band emission at 450.4 nm (2.75 eV) and 465.2 nm (2.66 eV) but with out yellow band emission. The room-temperature photoluminescence properties showed that it has also potential application in light-emitting devices. The tentative growth mechanism for the growth of dandelion-like GaN was also described.

  6. Synthesis, characterization, growth mechanism, photoluminescence and field emission properties of novel dandelion-like gallium nitride

    Science.gov (United States)

    Nabi, Ghulam; Cao, Chuanbao; Khan, Waheed S.; Hussain, Sajad; Usman, Zahid; Safdar, Muhammad; Shah, Sajjad Hussain; Khattak, Noor Abass Din

    2011-09-01

    Dandelion-like gallium nitride (GaN) microstructures were successfully synthesized via Ni catalyst assisted chemical vapor deposition method at 1200 °C under NH3 atmosphere by pre-treating precursors with aqueous ammonia. The as-synthesized product was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). X-ray diffraction analysis revealed that as-synthesized dandelion-like GaN was pure and has hexagonal wurtzite structure. SEM results showed that the size of the dandelion-like GaN structure was in the range of 30-60 μm. Dandelion-like GaN microstructures exhibited reasonable field emission properties with the turn-on field of 9.65 V μm-1 (0.01 mA cm-2) and threshold field of 11.35 V μm-1 (1 mA cm-2) which is sufficient for applications of electron emission devices, field emission displays and vacuum micro electronic devices. Optical properties were studied at room temperature by using fluorescence spectrophotometer. Photoluminescence (PL) measurements of dandelion-like GaN showed a strong near-band-edge emission at 370.2 nm (3.35 eV) with blue band emission at 450.4 nm (2.75 eV) and 465.2 nm (2.66 eV) but with out yellow band emission. The room-temperature photoluminescence properties showed that it has also potential application in light-emitting devices. The tentative growth mechanism for the growth of dandelion-like GaN was also described.

  7. Material properties of hollow clay tile and existing mortar characterization study

    International Nuclear Information System (INIS)

    Several Buildings at the Department of Energy (DOE) Oak Ridge Y-12 Plant were constructed (circa 1950) using unreinforced hollow clay tile masonry walls, which act as shear walls to resist lateral forces. A comprehensive test program, managed by the Center for Natural Phenomena Engineering (CNPE) of Martin Marietta Energy Systems, Inc. (MMES), is under way to determine material properties of existing hollow clay tile walls that will be used to help determine the structural strength of those buildings. This paper presents the results of several types of material property tests of 4-in.- and 8-in.-thick hollow clay tiles. These tests include determination of weight, size, void area, net area and gross area, initial rate of absorption, absorption, modulus of rupture, splitting tensile strength, and compressive strength. The tests were performed on old, reclaimed tiles and new tiles. A total of 336 tiles were tested. The stress-strain relationship for 40 specimens was also obtained. All testing was performed in accordance with ASTM standards and procedures developed by CNPE. This paper also presents the results of an investigation of mortar removed from the existing walls. The mortar characterization study was performed by Testwell Craig Materials Consultants under subcontract to MMES. Petrographic and chemical investigations were conducted on 18 mortar samples removed from four buildings at the plant. The primary purpose of the investigations was to evaluate the properties of existing mortar and provide a similar specification for the mortar to be used for construction of test specimens and test walls for the test program. The study showed variability in the mortars among buildings and among different locations within a building; however, it was concluded that an average mortar mix conforming to ASTM type N proportioned by volume of Portland cement, hydrated lime, and Tennessee river sand would be used to conduct further laboratory studies of masonry assemblages

  8. Synthesis, characterization, growth mechanism, photoluminescence and field emission properties of novel dandelion-like gallium nitride

    Energy Technology Data Exchange (ETDEWEB)

    Nabi, Ghulam [Research Centre of Materials Science, School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Cao Chuanbao, E-mail: cbcao@bit.edu.cn [Research Centre of Materials Science, School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Khan, Waheed S.; Hussain, Sajad; Usman, Zahid; Safdar, Muhammad [Research Centre of Materials Science, School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Shah, Sajjad Hussain [Department of Physics, School of Science, BIT, Beijing 100081 (China); Khattak, Noor Abass Din [Department of Physics, Gomal University, D.I. Khan, NWFP (Pakistan)

    2011-09-15

    Dandelion-like gallium nitride (GaN) microstructures were successfully synthesized via Ni catalyst assisted chemical vapor deposition method at 1200 deg. C under NH{sub 3} atmosphere by pre-treating precursors with aqueous ammonia. The as-synthesized product was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). X-ray diffraction analysis revealed that as-synthesized dandelion-like GaN was pure and has hexagonal wurtzite structure. SEM results showed that the size of the dandelion-like GaN structure was in the range of 30-60 {mu}m. Dandelion-like GaN microstructures exhibited reasonable field emission properties with the turn-on field of 9.65 V {mu}m{sup -1} (0.01 mA cm{sup -2}) and threshold field of 11.35 V {mu}m{sup -1} (1 mA cm{sup -2}) which is sufficient for applications of electron emission devices, field emission displays and vacuum micro electronic devices. Optical properties were studied at room temperature by using fluorescence spectrophotometer. Photoluminescence (PL) measurements of dandelion-like GaN showed a strong near-band-edge emission at 370.2 nm (3.35 eV) with blue band emission at 450.4 nm (2.75 eV) and 465.2 nm (2.66 eV) but with out yellow band emission. The room-temperature photoluminescence properties showed that it has also potential application in light-emitting devices. The tentative growth mechanism for the growth of dandelion-like GaN was also described.

  9. Preparation, characterization and electrochemical properties of a graphene-like carbon nano-fragment material

    International Nuclear Information System (INIS)

    Highlights: • The spent graphite material is utilized to prepare carbon nano-fragments (CNFs). • The preparation procedure is based on chemical oxidation and ultrasonic crushing. • The as-prepared graphene-like CNFs are systemically characterized. • The CNFs exhibit high electrocatalytic and electrochemical energy-storage properties. - Abstract: A graphene-like nanomaterial, carbon nano-fragments (CNFs), is obtained using the graphite anodes of spent lithium-ion batteries (LIBs) as carbon source, and its morphology, structure, functional groups, and reactivity are characterized to evaluate the properties and potential applications. The interlayer space increase, layer distortion, and remnant lithium of the waste lithium-intercalated graphite are utilized to prepare the oxidized CNFs (ox-CNFs) through a chemical oxidation and ultrasonic crushing process. These ox-CNFs exhibit a size distribution of 15 nm to 2 μm and excellent hydrophilicity, and disperse well in an aqueous suspension. Under the hydrothermal condition at 180 °C for 12 h, the ox-CNFs are converted into a suspension of reduced CNFs (re-CNFs), or a cylindrical aggregate when the concentration exceeds 2 mg·mL−1. The spectroscopic results demonstrate that there are abundant edges, defects, and functional groups existing on the CNFs, which affect their reactive, electronic, and electrochemical properties. Thereinto, the vacuum-dried ox-CNFs film can be converted from an insulator to a conductor after a chemical reduction by hydroiodic acid. And the re-CNFs modified glass carbon electrode (re-CNFs/GCE) exhibits enhanced electrocatalytic activity of about 8 times than the GCE to the oxidation reaction of dopamine. Furthermore, with the addition of the carboxylic ox-CNFs in aniline, the CNFs/polyaniline composite discharges a capacitance of 356.4 F·g−1 at 2 mV·s−1, an increase of 80.5% compared to the polyaniline. This preparation entails not only novel carbon nanomaterials but also an

  10. Size-dependent characterization of embedded Ge nanocrystals: Structural and thermal properties

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, L.L.; Giulian, R.; Sprouster, D.J.; Schnohr, C.S.; Llewellyn, D.J.; Kluth, P.; Cookson, D.J.; Foran, G.J.; Ridgway, M.C. (ASRP); (ANSTO); (ANU)

    2009-03-11

    A combination of conventional and synchrotron-based techniques has been used to characterize the size-dependent structural and thermal properties of Ge nanocrystals (NCs) embedded in a silica (a-SiO{sub 2}) matrix. Ge NC size distributions with four different diameters ranging from 4.0 to 9.0 nm were produced by ion implantation and thermal annealing as characterized with small-angle x-ray scattering and transmission electron microscopy. The NCs were well represented by the superposition of bulklike crystalline and amorphous environments, suggesting the formation of an amorphous layer separating the crystalline NC core and the a-SiO{sub 2} matrix. The amorphous fraction was quantified with x-ray-absorption near-edge spectroscopy and increased as the NC diameter decreased, consistent with the increase in surface-to-volume ratio. The structural parameters of the first three nearest-neighbor shells were determined with extended x-ray-absorption fine-structure (EXAFS) spectroscopy and evolved linearly with inverse NC diameter. Specifically, increases in total disorder, interatomic distance, and the asymmetry in the distribution of distances were observed as the NC size decreased, demonstrating that finite-size effects govern the structural properties of embedded Ge NCs. Temperature-dependent EXAFS measurements in the range of 15-300 K were employed to probe the mean vibrational frequency and the variation of the interatomic distance distribution (mean value, variance, and asymmetry) with temperature for all NC distributions. A clear trend of increased stiffness (higher vibrational frequency) and decreased thermal expansion with decreasing NC size was evident, confirming the close relationship between the variation of structural and thermal/vibrational properties with size for embedded Ge NCs. The increase in surface-to-volume ratio and the presence of an amorphous Ge layer separating the matrix and crystalline NC core are identified as the main factors responsible for

  11. Characterizing the Material Properties of Polymer-Based Microelectrode Arrays for Retinal Prosthesis

    Energy Technology Data Exchange (ETDEWEB)

    Park, C S; Maghribi, M

    2003-05-10

    The Retinal Prosthesis project is a three year project conducted in part at the Lawrence Livermore National Laboratory and funded by the Department of Energy to create an epiretinal microelectrode array for stimulating retinal cells. The implant must be flexible to conform to the retina, robust to sustain handling during fabrication and implantation, and biocompatible to withstand physiological conditions within the eye. Using poly(dimethyl siloxane) (PDMS), LLNL aims to use microfabrication techniques to increase the number of electrodes and integrate electronics. After the initial designs were fabricated and tested in acute implantation, it became obvious that there was a need to characterize and understand the mechanical and electrical properties of these new structures. This knowledge would be imperative in gaining credibility for polymer microfabrication and optimizing the designs. Thin composite microfabricated devices are challenging to characterize because they are difficult to handle, and exhibit non-linear, viscoelastic, and anisotropic properties. The objective of this research is to device experiments and protocols, develop an analytical model to represent the composite behavior, design and fabricate test structures, and conduct experimental testing to determine the mechanical and electrical properties of PDMS-metal composites. Previous uniaxial stretch tests show an average of 7% strain before failure on resistive heaters of similar dimensions deposited on PDMS. Lack of background information and questionable human accuracy demands a more sophisticated and thorough testing method. An Instron tensile testing machine was set up to interface with a digital multiplexor and computer interface to simultaneously record and graph position, load, and resistance across devices. With a compliant load cell for testing polymers and electrical interconnect grips designed and fabricated to interface the sample to the electronics, real-time resistance measurements

  12. Predicting fatigue properties of cast aluminum by characterizing small-crack propagation behavior

    Science.gov (United States)

    Caton, Michael John

    2001-07-01

    The increased use of cast aluminum in structural components requires a deeper understanding of the mechanisms controlling fatigue properties in order to enable improved predictive capabilities. Of particular interest is the ability to model the influence of processing variables on the fatigue performance of alloys used in automotive applications such as engine blocks and cylinder heads. This thesis describes the results of a study conducted on cast W319 aluminum, a commercial Al-Si-Cu alloy used in automotive engine components, and presents a model that effectively predicts fatigue properties in this alloy as a function of material condition. The very high cycle fatigue regime (˜109 cycles) was examined using ultrasonic testing equipment (20 kHz) and distinct endurance limits were observed. The initiation and propagation of small fatigue cracks (˜5 mum to 2 mm) were monitored by a standard replication technique. It was observed that cracks initiate almost exclusively from microshrinkage pores and that the initiation life is negligible even at stresses below the endurance limit. The endurance limits result from the arrest of small cracks. Small crack growth rates were determined for a variety of material conditions where the influence of solidification time, heat treatment, and grain refinement were investigated. In addition, the influences of applied stress amplitude, stress ratio, and loading frequency on small crack growth were examined. A significant small crack effect was identified in this alloy and standard correlating parameters such as DeltaK and DeltaJ do not adequately characterize small crack growth. A correlating parameter written as [(epsilonmax sigmaa/sigma yield)s a] is proposed and shown to effectively characterize small crack growth for a wide range of stresses and a wide range of solidification conditions. In this parameter, epsilonmax is the total strain corresponding to the maximum applied stress, sigmaa is the stress amplitude, sigma yield is

  13. Use and utility of combined solute and heat tracer tests for characterizing hydrogeothermal properties of an alluvial aquifer

    OpenAIRE

    Klepikova, Maria; Wildemeersch, Samuel; Jamin, Pierre; Orban, Philippe; Hermans, Thomas; Nguyen, Frédéric; Brouyère, Serge; Dassargues, Alain

    2015-01-01

    Using heat as a tracer together with a solute tracer is interesting for characterizing hydrogeothermal properties of the underground. These properties are particularly needed to dimension any low temperature geothermal project using an open doublet system (pumping-reinjection) in a shallow aquifer. The tracing experiment, conducted in the alluvial aquifer of the River Meuse (Hermalle near Liège), consisted in injecting simultaneously heated water at 40°C and a dye tracer in a piezometer and m...

  14. A study on the medicinal mushroom Cordyceps militaris (L.) link: chemical characterization, antioxidant, antimicrobial and antiproliferative properties

    OpenAIRE

    Reis, Filipa S.; Stojković, Dejan; Glamočlija, Jasmina; Ćirić, Ana; Van Griensven, Leo J. L. D.; Soković, Marina; Isabel C. F. R. Ferreira

    2013-01-01

    The Cordyceps genus is well known for its medicinal properties. A number of bioactive constituents from Cordyceps species have been reported such as antibacterial, antifungal, immunopotentiating or antitumor agents [1]. The anti-inflammatory and anti-angiogenic properties of Cordyceps militaris (L.) Link have been reported as also the antioxidant activity of its cultured mycelium [2]. In this work, the chemical characterization of C. militaris was performed, includingbioactive ...

  15. Dual energy CT-based characterization of x-ray attenuation properties of breast equivalent material plates

    OpenAIRE

    N. Geeraert; Klaus, R.; Guidici, Philippe; Muller, S; Cockmartin, Lesley; Bosmans, H.

    2012-01-01

    Breast density is more and more considered as an important risk factor for breast cancer and several quantitative breast density evaluation methods have been proposed. The reference material for simulation of the breast attenuation proper-ties of glandular and adipose breast tissues is manufactured by a single provider. In order to characterize the attenuation properties of these materials, measurements in Hounsfield Units (HU) have been performed using a CT-scanner. Breast-equivalent plates ...

  16. An experimental test plan for the characterization of molten salt thermochemical properties in heat transport systems

    Energy Technology Data Exchange (ETDEWEB)

    Pattrick Calderoni

    2010-09-01

    Molten salts are considered within the Very High Temperature Reactor program as heat transfer media because of their intrinsically favorable thermo-physical properties at temperatures starting from 300 C and extending up to 1200 C. In this context two main applications of molten salt are considered, both involving fluoride-based materials: as primary coolants for a heterogeneous fuel reactor core and as secondary heat transport medium to a helium power cycle for electricity generation or other processing plants, such as hydrogen production. The reference design concept here considered is the Advanced High Temperature Reactor (AHTR), which is a large passively safe reactor that uses solid graphite-matrix coated-particle fuel (similar to that used in gas-cooled reactors) and a molten salt primary and secondary coolant with peak temperatures between 700 and 1000 C, depending upon the application. However, the considerations included in this report apply to any high temperature system employing fluoride salts as heat transfer fluid, including intermediate heat exchangers for gas-cooled reactor concepts and homogenous molten salt concepts, and extending also to fast reactors, accelerator-driven systems and fusion energy systems. The purpose of this report is to identify the technical issues related to the thermo-physical and thermo-chemical properties of the molten salts that would require experimental characterization in order to proceed with a credible design of heat transfer systems and their subsequent safety evaluation and licensing. In particular, the report outlines an experimental R&D test plan that would have to be incorporated as part of the design and operation of an engineering scaled facility aimed at validating molten salt heat transfer components, such as Intermediate Heat Exchangers. This report builds on a previous review of thermo-physical properties and thermo-chemical characteristics of candidate molten salt coolants that was generated as part of the

  17. Characterizing Aerosol Distributions and Optical Properties Using the NASA Langley High Spectral Resolution Lidar

    Energy Technology Data Exchange (ETDEWEB)

    Hostetler, Chris; Ferrare, Richard

    2013-02-14

    The objective of this project was to provide vertically and horizontally resolved data on aerosol optical properties to assess and ultimately improve how models represent these aerosol properties and their impacts on atmospheric radiation. The approach was to deploy the NASA Langley Airborne High Spectral Resolution Lidar (HSRL) and other synergistic remote sensors on DOE Atmospheric Science Research (ASR) sponsored airborne field campaigns and synergistic field campaigns sponsored by other agencies to remotely measure aerosol backscattering, extinction, and optical thickness profiles. Synergistic sensors included a nadir-viewing digital camera for context imagery, and, later in the project, the NASA Goddard Institute for Space Studies (GISS) Research Scanning Polarimeter (RSP). The information from the remote sensing instruments was used to map the horizontal and vertical distribution of aerosol properties and type. The retrieved lidar parameters include profiles of aerosol extinction, backscatter, depolarization, and optical depth. Products produced in subsequent analyses included aerosol mixed layer height, aerosol type, and the partition of aerosol optical depth by type. The lidar products provided vertical context for in situ and remote sensing measurements from other airborne and ground-based platforms employed in the field campaigns and was used to assess the predictions of transport models. Also, the measurements provide a data base for future evaluation of techniques to combine active (lidar) and passive (polarimeter) measurements in advanced retrieval schemes to remotely characterize aerosol microphysical properties. The project was initiated as a 3-year project starting 1 January 2005. It was later awarded continuation funding for another 3 years (i.e., through 31 December 2010) followed by a 1-year no-cost extension (through 31 December 2011). This project supported logistical and flight costs of the NASA sensors on a dedicated aircraft, the subsequent

  18. Fabricating and Characterizing Physical Properties of Electrospun Polypeptide-based Nanofibers

    Science.gov (United States)

    Khadka, Dhan Bahadur

    This dissertation has aimed to fabricate polypeptide based biomaterial and characterize physical properties. Electrospinning is used as a tool for the sample fabrication. Project focused on determining the feasibility of electrospinning of certain synthetic polypeptides and certain elastin-like peptides from aqueous feedstocks and to characterize physical properties of polymer aqueous solution, cast film and spun fibers and fiber mats. The research involves peptide design, polymer electrospinning, fibers crosslinking, determining the extent of crosslinking, fibers protease degradation study, fibers stability and self-organization analysis, structure and composition determination by various spectroscopy and microscopy techniques and characterization of mechanical properties of individual suspended fibers. Fiber mats of a synthetic cationic polypeptide poly(L-ornithine) (PLO) and an anionic co-polypeptide of L-glutamic acid and L-tyrosine (PLEY) of defined composition have been produced by electrospinning. Fibers were obtained from polymer aqueous solution at concentrations of 20-45% (w/v) in PLO and at concentrations of 20-60% (w/v) in PLEY. Applied voltage and spinneret-collector distance were also found to influence polymer spinnability and fibers morphology. Oriented fibers were obtained by parallel electrodes geometry. Fiber diameter and morphology was analyzed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). PLO fibers exposed on glutaraldehyde (GTA) vapor rendered fiber mats water-insoluble. A common chemical reagent, carbodiimide was used to crosslink PLEY fibers. Fiber solubility in aqueous solution varied as a function of crosslinking time and crosslinker concentration. Crosslink density has been quantified by a visible-wavelength dye-based method. Degradation of crosslinked fibers by different proteases has been demonstrated. Investigation of crosslinked PLEY fibers has provided insight into the mechanisms of stability at different

  19. Characterization of functional properties of Enterococcus faecium strains isolated from human gut.

    Science.gov (United States)

    İspirli, Hümeyra; Demirbaş, Fatmanur; Dertli, Enes

    2015-11-01

    The aim of this work was to characterize the functional properties of Enterococcus faecium strains identified after isolation from human faeces. Of these isolates, strain R13 showed the best resistance to low pH, bile salts, and survival in the simulated in vitro digestion assay, and demonstrated an important level of adhesion to hexadecane as a potential probiotic candidate. Analysis of the antibiotic resistance of E. faecium strains indicated that in general these isolates were sensitive to the tested antibiotics and no strain appeared to be resistant to vancomycin. Examination of the virulence determinants for E. faecium strains demonstrated that all strains contained the virulence genes common in gut- and food-originated enterococci, and strain R13 harboured the lowest number of virulence genes. Additionally, no strain contained the genes related to cytolysin metabolism and showed hemolytic activity. The antimicrobial role of E. faecium strains was tested against several pathogens, in which different levels of inhibitory effects were observed, and strain R13 was inhibitory to all tested pathogens. PCR screening of genes encoding enterocin A and B indicated the presence of these genes in E. faecium strains. Preliminary characterization of bacteriocins revealed that their activity was lost after proteolytic enzyme treatments, but no alteration in antimicrobial activity was observed at different pHs (3.5 to 9.5) and after heat treatments. In conclusion, this study revealed the functional characteristics of E. faecium R13 as a gut isolate, and this strain could be developed as a new probiotic after further tests. PMID:26485327

  20. Characterization of Anticancer, Antimicrobial, Antioxidant Properties and Chemical Compositions of Peperomia Pellucida Leaf Extract

    Directory of Open Access Journals (Sweden)

    Desy Fitrya Syamsumir

    2011-10-01

    Full Text Available Peperomia pellucida leaf extract was characterized for its anticancer, antimicrobial, antioxidant activities, and chemical compositions. Anticancer activity of P. pellucida leaf extract was determined through Colorimetric MTT (tetrazolium assay against human breast adenocarcinoma (MCF-7 cell line and the antimicrobial property of the plant extract was revealed by using two-fold broth micro-dilution method against 10 bacterial isolates. Antioxidant activity of the plant extract was then characterized using α, α-diphenyl-β-picrylhydrazyl (DPPH radical scavenging method and the chemical compositions were screened and identified using gas chromatography-mass spectrometry (GC-MS. The results of present study indicated that P. pellucida leaf extract possessed anticancer activities with half maximal inhibitory concentration (IC50 of 10.4±0.06 µg/ml. The minimum inhibitory concentration (MIC values were ranged from 31.25 to 125 mg/l in which the plant extract was found to inhibit the growth of Edwardsiella tarda, Escherichia coli, Flavobacterium sp., Pseudomonas aeruginosa and Vibrio cholerae at 31.25 mg/l; Klebsiella sp., Aeromonas hydrophila and Vibrio alginolyticus at 62.5 mg/l; and it was able to control the growth of Salmonella sp. and Vibrio parahaemolyticus at 125 mg/l. At the concentration of 0.625 ppt, the plant extract was found to inhibit 30% of DPPH, free radical. Phytol (37.88% was the major compound in the plant extract followed by 2-Naphthalenol, decahydro- (26.20%, Hexadecanoic acid, methyl ester (18.31% and 9,12-Octadecadienoic acid (Z,Z-, methyl ester (17.61%. Findings from this study indicated that methanol extract of P. pellucida leaf possessed vast potential as medicinal drug especially in breast cancer treatment.

  1. Characterization and modeling of structural properties of SiGe/Si superlattices upon annealing

    Science.gov (United States)

    Py, M.; Barnes, J. P.; Rivallin, P.; Pakfar, A.; Denneulin, T.; Cooper, D.; Hartmann, J. M.

    2011-08-01

    Stacked multichannel or nanowire CMOS transistors are foreseen as viable options in future technology nodes. Superior electric performances and a relative immunity to short channel effects have already been demonstrated in such devices. They rely on (i) the epitaxy of SiGe/Si superlattices, (ii) the anisotropic etching of the source and drain (S/D) blocks and the channels, and (iii) the high degree of selectivity that can be achieved when laterally etching the SiGe sacrificial layers. The voids left by the removal of SiGe are then conformally filled by HfO2/TiN/poly-Si gates, leading to the formation of multichannel devices. Doping elements can be included in situ in the SiGe layers during the epitaxial step in order to achieve a proper S/D doping after annealing. Precise knowledge of the diffusion behavior of all species is then crucial to understand and tailor final device performance. In this work, we investigated the properties of intrinsic or in situ doped (with B, C, or P) SiGe/Si superlattices upon annealing, using several characterization techniques, such as x-ray diffraction, x-ray reflectivity, time-of-flight-secondary ion mass spectrometry, and dark-field electron holography; as well as diffusion simulation tools such as S-Process. The combined analysis and simulation approaches allowed a complete characterization of the studied structures upon annealing. In the first step, the diffusion of both germanium and dopants was observed experimentally and quantified with simulation. Their diffusion mechanisms were also studied. In the second step, the evolution of the strain distribution upon annealing was experimentally monitored and simulated to quantify the strain relaxation in such structures.

  2. Characterizing riverbed sediment using high-frequency acoustics 1: spectral properties of scattering

    Science.gov (United States)

    Buscombe, Daniel D.; Grams, Paul E.; Kaplinski, Matt A.

    2014-01-01

    Bed-sediment classification using high-frequency hydro-acoustic instruments is challenging when sediments are spatially heterogeneous, which is often the case in rivers. The use of acoustic backscatter to classify sediments is an attractive alternative to analysis of topography because it is potentially sensitive to grain-scale roughness. Here, a new method is presented which uses high-frequency acoustic backscatter from multibeam sonar to classify heterogeneous riverbed sediments by type (sand, gravel,rock) continuously in space and at small spatial resolution. In this, the first of a pair of papers that examine the scattering signatures from a heterogeneous riverbed, methods are presented to construct spatially explicit maps of spectral properties from geo-referenced point clouds of geometrically and radiometrically corrected echoes. Backscatter power spectra are computed to produce scale and amplitude metrics that collectively characterize the length scales of stochastic measures of riverbed scattering, termed ‘stochastic geometries’. Backscatter aggregated over small spatial scales have spectra that obey a power-law. This apparently self-affine behavior could instead arise from morphological- and grain-scale roughnesses over multiple overlapping scales, or riverbed scattering being transitional between Rayleigh and geometric regimes. Relationships exist between stochastic geometries of backscatter and areas of rough and smooth sediments. However, no one parameter can uniquely characterize a particular substrate, nor definitively separate the relative contributions of roughness and acoustic impedance (hardness). Combinations of spectral quantities do, however, have the potential to delineate riverbed sediment patchiness, in a data-driven approach comparing backscatter with bed-sediment observations (which is the subject of part two of this manuscript).

  3. Synthesis, characterization, magnetic and electrochemical properties of a new 3D hexa-copper-substituted germanotungstate

    International Nuclear Information System (INIS)

    An inorganic–organic hybrid hexa-copper-substituted germanotungstate Na2[Cu(dap)2]2[Cu(dap)2] ([Cu6(H2O)2(dap)2][B-α-GeW9O34]2)·4H2O (1) (dap=1,2-diaminopropane) has been hydrothermally prepared and characterized by elemental analyses, inductively coupled plasma atomic emission spectrometry (ICP–AES) analyses, IR spectra, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA) and single-crystal X-ray diffraction. 1 displays the six-connected 3D network with the long topological (O′Keefe) vertex symbol is 4·4·64·4·4·4·4·64·4·4·4·64·4·4·4 and the short vertex (Schläfli) symbol of 41263. Magnetic measurements indicate that there are the overall ferromagnetic exchange interactions in the belt-like hexa-CuII cluster in 1. Furthermore, the electrochemical behavior and electrocatalysis of 1 modified carbon paste electrode (1-CPE) have been studied. The reductions of nitrite, bromate and hydrogen peroxide are principally mediated by the WVI-based wave. - Graphical abstract: A hexa-CuII sandwiched germanotungstate has been synthesized and structurally characterized. The magnetic, solid-state electrochemical and electrocatalytic properties have been investigated. Display Omitted - Highlights: • Transition-metal substituted polyoxometalates. • Hexa-copper-substituted germanotungstate. • Six-connected 3D network. • Electrocatalytic reduction of nitrite, bromate and hydrogen peroxide

  4. Characterization of signal properties in atherosclerotic plaque components by intravascular MRI.

    Science.gov (United States)

    Rogers, W J; Prichard, J W; Hu, Y L; Olson, P R; Benckart, D H; Kramer, C M; Vido, D A; Reichek, N

    2000-07-01

    Magnetic resonance imaging (MRI) is capable of distinguishing between atherosclerotic plaque components solely on the basis of biochemical differences. However, to date, the majority of plaque characterization has been performed by using high-field strength units or special coils, which are not clinically applicable. Thus, the purpose of the present study was to evaluate MRI properties in histologically verified plaque components in excised human carotid endarterectomy specimens with the use of a 5F catheter-based imaging coil, standard acquisition software, and a clinical scanner operating at 0.5 T. Human carotid endarterectomy specimens from 17 patients were imaged at 37 degrees C by use of an opposed solenoid intravascular radiofrequency coil integrated into a 5F double-lumen catheter interfaced to a 0.5-T General Electric interventional scanner. Cross-sectional intravascular MRI (156x250 microm in-plane resolution) that used different imaging parameters permitted the calculation of absolute T1and T2, the magnetization transfer contrast ratio, the magnitude of regional signal loss associated with an inversion recovery sequence (inversion ratio), and regional signal loss in gradient echo (gradient echo-to-spin echo ratio) in plaque components. Histological staining included hematoxylin and eosin, Masson's trichrome, Kossa, oil red O, and Gomori's iron stain. X-ray micrographs were also used to identify regions of calcium. Seven plaque components were evaluated: fibrous cap, smooth muscle cells, organizing thrombus, fresh thrombus, lipid, edema, and calcium. The magnetization transfer contrast ratio was significantly less in the fibrous cap (0.62+/-13) than in all other components (Psmooth muscle cells) were not significantly different between groups. In vitro intravascular MRI with catheter-based coils and standard software permits sufficient spatial resolution to visualize major plaque components. Pulse sequences that take advantage of differences in biochemical

  5. γ-MnS nano and micro architectures: Synthesis, characterization and optical properties

    International Nuclear Information System (INIS)

    Highlights: → In this article we have reported the formation of γ-MnS nano/microcrystalline material by a novel proposed route. Na2[Mn(HL)2(H2O)2]; 1:2 (M:L) chelate complex was synthesized in the first step by our previously reported method. The chelate complex precursor was subsequently decomposed by alkaline solution of thiocarbamide, resulting formation of γ-MnS crystals in situ. → The effect of reaction time and surfactant have been observed and discussed. The materials were characterized for crystallanity and morphology by SEM, TEM, XRD, UV-Vis, PL spectra and the results are thoroughly discussed. → γ-MnS crystals were formed when metal complex was used as metal source whereas Mn3O4 was the dominant product when MnSO4.H2O was used as metal source. → We have also proposed a plausible formation mechanism based on experimental evidence, analyses and previous reports. → Optical property of the material has also been discussed in the present article. -- Abstract: γ-MnS nanocrystalline materials have been prepared by reaction of Na2[Mn(HL)2(H2O)2]; 1:2 (M:L) chelate complex with alkaline solution of thiocarbamide in aqueous solution phase. Effect of metal chelate complex, reaction time and surfactant sodium dodecyl sulfate; SDS on phase, morphology and size of the products have been investigated. The metal chelate complex was synthesized by reacting Mn(II) ions with eriochrome black T (NaH2L) in alkaline medium. γ-MnS crystals were formed when metal complex was used as metal source whereas Mn3O4 was the dominant product when MnSO4.H2O was used as metal source. Materials thus formed having various morphologies were characterized by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM) to determine the crystallinity, phase, structure and morphology. The optical properties of the thus prepared samples were determined by UV-vis absorption spectra and photoluminescence spectra. A possible formation mechanism of

  6. Characterization and antibacterial properties of stable silver substituted hydroxyapatite nanoparticles synthesized through surfactant assisted microwave process

    International Nuclear Information System (INIS)

    Highlights: • Stable nano sized silver substitute hydroxyapatite is prepared under surfactant assisted microwave process at 600 W power for 7 min. • The nanoparticles are in the size range of 58–72 nm and exert uniform elongated spheroid morphology. • Increase in silver concentration resulted in better dielectric properties. • Good antibacterial activity and silver release. - Abstract: The present study reports a relatively simple method for the synthesis of stable silver substituted hydroxyapatite nanoparticles with controlled morphology and particle size. In order to achieve this, CTAB is included as a surfactant in the microwave refluxing process (600 W for 7 min). The nanoparticles produced with different silver ion concentrations (0.05, 0.1 and 0.2 wt%) were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscope (FESEM), energy dispersive X-ray (EDX) and Brunauer–Emmett–Teller (BET) analysis. XRD and FTIR analyses reveal that the Ag-HA nanoparticles were phase pure at 1000 °C. FESEM images showed that the produced nanoparticles are in the size range of 58–72 nm and exert uniform elongated spheroid morphology. The dielectric properties suggest that the increase in dielectric constant (ε′) and dissipation factor (D) values with increasing Ag concentrations. Antibacterial performance of the Ag-HA samples elucidated using disk diffusion technique (DDT) and minimum inhibitory concentration (MIC) demonstrates anti-bacterial activity against Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa and Escherichia coli. This effect was dose dependent and was more pronounced against Gram-negative bacteria than Gram-positive organisms

  7. Structural- and optical-property characterization of three-dimensional branched ZnO nanospikes

    International Nuclear Information System (INIS)

    Current study reports the synthesis of three-dimensional (3-D) ZnO nanospikes with anomalous optical property, where zinc stearate is adopted as a safe, common and low-cost precursor that undergoes thermal pyrolysis under non-hydrolytic approach. High resolution transmission electron microscope (HRTEM) and scanning electron microscope (SEM) result show that the as-synthesized 3-D ZnO nanospikes are constructed by bundle of nanorods that sprout radially outwards in random orientation. The possible growth mechanism is discussed by referring to the microscopy results. X-ray diffraction (XRD) pattern confirms that the nanospikes are highly crystalline, which existed in hexagonal wurtzite crystal structure. Optical absorption characterization shows that the onset absorption for the nanospikes is slightly red-shifted if compared to commercial ZnO and the corresponding bandgap energy is estimated to be 3.1 eV. The photoluminescene (PL) result of ZnO nanospikes indicate that its optical emission exhibits weak UV emission but very intense visible-light emission that ranged from green- up to red-region. The factors that contributed to the intriguing PL characteristic are discussed. Current finding would offer a versatile synthesis scheme in engineering advanced nanostructures with new design that exhibit congruent optical property. - Graphical abstract: Display Omitted - Highlights: • Pyrolysis of zinc stearate in synthesizing 3-D ZnO nanospikes • ZnO nanospikes possess bundle of nanorods that sprout out from the hexagonal stump • Growth mechanism is deduced to elucidate the morphological evolution from nanobullet to nanospike with branching topology • PL spectrum indicate that the nanospike exhibit prominent visible-light emission that ranged from green- to red-region

  8. Characterization of porous glass fiber-reinforced composite (FRC) implant structures: porosity and mechanical properties.

    Science.gov (United States)

    Ylä-Soininmäki, Anne; Moritz, Niko; Lassila, Lippo V J; Peltola, Matti; Aro, Hannu T; Vallittu, Pekka K

    2013-12-01

    The aim of this study was to characterize the microstructure and mechanical properties of porous fiber-reinforced composites (FRC). Implants made of the FRC structures are intended for cranial applications. The FRC specimens were prepared by impregnating E-glass fiber sheet with non-resorbable bifunctional bis-phenyl glycidyl dimethacrylate and triethylene glycol dimethacrylate resin matrix. Four groups of porous FRC specimens were prepared with a different amount of resin matrix. Control group contained specimens of fibers, which were bound together with sizing only. Microstructure of the specimens was analyzed using a micro computed tomography (micro-CT) based method. Mechanical properties of the specimens were measured with a tensile test. The amount of resin matrix in the specimens had an effect on the microstructure. Total porosity was 59.5 % (median) in the group with the lowest resin content and 11.2 % (median) in the group with the highest resin content. In control group, total porosity was 94.2 % (median). Correlations with resin content were obtained for all micro-CT based parameters except TbPf. The tensile strength of the composites was 21.3 MPa (median) in the group with the highest resin content and 43.4 MPa (median) in the group with the highest resin content. The tensile strength in control group was 18.9 MPa (median). There were strong correlations between the tensile strength of the specimens and most of the micro-CT based parameters. This experiment suggests that porous FRC structures may have the potential for use in implants for cranial bone reconstructions, provided further relevant in vitro and in vivo tests are performed. PMID:23929214

  9. Cassava Peels for Alternative Fibre in Pulp and Paper Industry: Chemical Properties and Morphology Characterization

    Directory of Open Access Journals (Sweden)

    Ashuvila Mohd Aripin

    2013-11-01

    Full Text Available Without a proper waste management, the organic wastes such as cassava peels could result in increased amount of solid waste dump into landfill. This study aims to use non-wood organic wastes as pulp for paper making industries; promoting the concept of ‘from waste to wealth and recyclable material’. The objective  of this study is to determine the potential of casssava peel as alternative fibre in pulp and paper based on its chemical properties and surface morphology characteristic. Quantified parameters involved are holocellulose, cellulose, hemicellulose, lignin, one percent of sodium hydroxide, hot water solubility and ash content. The chemical characterization was in accordance with relevant TAPPI Test, Kurscher-Hoffner and Chlorite methods. Scanning electron microscopy (SEM was used to observe and determine the morphological characteristic of untreated cassava peels fibre. In order to propose the suitability of the studied plant as an alternative fibre resource in pulp and paper making, the obtained results are compared to other published literatures especially from wood sources. Results indicated that the amount of holocellulose contents in cassava peels (66% is the lowest than of wood (70 - 80.5% and canola straw (77.5%; however this value is still within the limit suitability to produce paper. The lignin content (7.52% is the lowest than those of all wood species (19.9-26.22%. Finally, the SEM images showed that untreated cassava peel contains abundance fibre such as hemicellulose and cellulose that is hold by the lignin in it. In conclusion, chemical properties and morphological characteristics of cassava peel indicated that it is suitable to be used as an alternative fibre sources for pulp and paper making industry, especially in countries with limited wood resources

  10. Characterization and antibacterial properties of stable silver substituted hydroxyapatite nanoparticles synthesized through surfactant assisted microwave process

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, Nida [Medical Implant Technology Group (MEDITEG), Faculty of Bioscience and Medical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor Darul Takzim (Malaysia); Abdul Kadir, Mohammed Rafiq, E-mail: rafiq@biomedical.utm.my [Medical Implant Technology Group (MEDITEG), Faculty of Bioscience and Medical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor Darul Takzim (Malaysia); Nik Malek, Nik Ahmad Nazim [Faculty of Bioscience and Medical Engineering (FBME), Universiti Teknologi Malaysia, 81310 Skudai, Johor Darul Takzim (Malaysia); Mahmood, Nasrul Humaimi Bin [Medical Implant Technology Group (MEDITEG), Faculty of Bioscience and Medical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor Darul Takzim (Malaysia); Murali, Malliga Raman; Kamarul, T. [Tissue Engineering Group, NOCERAL, Department of Orthopaedic Surgery, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2013-09-01

    Highlights: • Stable nano sized silver substitute hydroxyapatite is prepared under surfactant assisted microwave process at 600 W power for 7 min. • The nanoparticles are in the size range of 58–72 nm and exert uniform elongated spheroid morphology. • Increase in silver concentration resulted in better dielectric properties. • Good antibacterial activity and silver release. - Abstract: The present study reports a relatively simple method for the synthesis of stable silver substituted hydroxyapatite nanoparticles with controlled morphology and particle size. In order to achieve this, CTAB is included as a surfactant in the microwave refluxing process (600 W for 7 min). The nanoparticles produced with different silver ion concentrations (0.05, 0.1 and 0.2 wt%) were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscope (FESEM), energy dispersive X-ray (EDX) and Brunauer–Emmett–Teller (BET) analysis. XRD and FTIR analyses reveal that the Ag-HA nanoparticles were phase pure at 1000 °C. FESEM images showed that the produced nanoparticles are in the size range of 58–72 nm and exert uniform elongated spheroid morphology. The dielectric properties suggest that the increase in dielectric constant (ε′) and dissipation factor (D) values with increasing Ag concentrations. Antibacterial performance of the Ag-HA samples elucidated using disk diffusion technique (DDT) and minimum inhibitory concentration (MIC) demonstrates anti-bacterial activity against Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa and Escherichia coli. This effect was dose dependent and was more pronounced against Gram-negative bacteria than Gram-positive organisms.

  11. Structural- and optical-property characterization of three-dimensional branched ZnO nanospikes

    Energy Technology Data Exchange (ETDEWEB)

    Chia, M.Y. [Low Dimensional Materials Research Centre, Department of Physics, Faculty of Science, University Malaya, 50603, Lembah Pantai, Kuala Lumpur (Malaysia); Chiu, W.S., E-mail: w.s.chiu@um.edu.my [Low Dimensional Materials Research Centre, Department of Physics, Faculty of Science, University Malaya, 50603, Lembah Pantai, Kuala Lumpur (Malaysia); Daud, S.N.H. [Low Dimensional Materials Research Centre, Department of Physics, Faculty of Science, University Malaya, 50603, Lembah Pantai, Kuala Lumpur (Malaysia); Khiew, P.S. [Faculty of Engineering, University of Nottingham Malaysia Campus, 43500 Semenyih, Selangor (Malaysia); Radiman, S.; Abd-Shukor, R.; Hamid, M.A.A. [School of Applied Physics, Faculty of Science & Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2015-08-15

    Current study reports the synthesis of three-dimensional (3-D) ZnO nanospikes with anomalous optical property, where zinc stearate is adopted as a safe, common and low-cost precursor that undergoes thermal pyrolysis under non-hydrolytic approach. High resolution transmission electron microscope (HRTEM) and scanning electron microscope (SEM) result show that the as-synthesized 3-D ZnO nanospikes are constructed by bundle of nanorods that sprout radially outwards in random orientation. The possible growth mechanism is discussed by referring to the microscopy results. X-ray diffraction (XRD) pattern confirms that the nanospikes are highly crystalline, which existed in hexagonal wurtzite crystal structure. Optical absorption characterization shows that the onset absorption for the nanospikes is slightly red-shifted if compared to commercial ZnO and the corresponding bandgap energy is estimated to be 3.1 eV. The photoluminescene (PL) result of ZnO nanospikes indicate that its optical emission exhibits weak UV emission but very intense visible-light emission that ranged from green- up to red-region. The factors that contributed to the intriguing PL characteristic are discussed. Current finding would offer a versatile synthesis scheme in engineering advanced nanostructures with new design that exhibit congruent optical property. - Graphical abstract: Display Omitted - Highlights: • Pyrolysis of zinc stearate in synthesizing 3-D ZnO nanospikes • ZnO nanospikes possess bundle of nanorods that sprout out from the hexagonal stump • Growth mechanism is deduced to elucidate the morphological evolution from nanobullet to nanospike with branching topology • PL spectrum indicate that the nanospike exhibit prominent visible-light emission that ranged from green- to red-region.

  12. Fabrication, characterization, and mechanical properties of spark plasma sintered Al–BN nanoparticle composites

    Energy Technology Data Exchange (ETDEWEB)

    Firestein, Konstantin L., E-mail: kosty@firestein.ru [National University of Science and Technology “MISIS”, Leninsky prospect 4, Moscow 119049 (Russian Federation); Steinman, Alexander E.; Golovin, Igor S. [National University of Science and Technology “MISIS”, Leninsky prospect 4, Moscow 119049 (Russian Federation); Cifre, Joan [Universitat de les Illes Balears, Ctra. de Valldemossa, km. 7.5, E-07122 Palma de Mallorca (Spain); Obraztsova, Ekaterina A.; Matveev, Andrei T.; Kovalskii, Andrey M. [National University of Science and Technology “MISIS”, Leninsky prospect 4, Moscow 119049 (Russian Federation); Lebedev, Oleg I. [CRISMAT, UMR 6508, CNRS-ENSICAEN, 6Bd Marechal Juin, 14050 Caen (France); Shtansky, Dmitry V., E-mail: shtansky@shs.misis.ru [National University of Science and Technology “MISIS”, Leninsky prospect 4, Moscow 119049 (Russian Federation); Golberg, Dmitri, E-mail: golberg.dmitri@nims.go.jp [World Premier International Center for Materials Nanoarchitectonics (WPI-MANA) National Institute for Materials Science (NIMS), Namiki 1, Tsukuba, Ibaraki 3050044 (Japan)

    2015-08-26

    Fabrication of high strength yet light and low cost composite materials with good mechanical properties at room and elevated temperatures is a challenge that metallurgy and materials science communities are facing for many years, and no “dream material” has been developed so far. The primary goal of this study was to fabricate, characterize, and to carry out tensile tests on Al-based composite materials strengthened with commercially-available BN nanoparticles (BNNPs). The composites were fabricated by spark plasma sintering (SPS) technique. The structures of powder mixtures and composite materials, as well as their fracture surfaces, were studied by scanning and transmission electron microscopy. The influence of BNNPs content (0.5, 1.5, 3, 4.5, 6, and 7.5 wt%) and holding times (5, 60, and 300 min) at 600 °C during SPS on the tensile strength was investigated. A maximum increase in strength was observed for Al-based composites with 4.5 wt% of BNNPs. The sample demonstrated a 50% increase in tensile strength compared with pristine Al. Although the tensile tests performed at 300 °C revealed that the tensile strength became 20% lower than the strength at room temperature, it was, however, still 75% higher compared with that of the pure Al at 300 °C. In addition, at 300 °C the Al–BNNPs composites demonstrated a much higher value of yield stress, about 115 MPa, which is 190% higher than that of pure Al at the same temperature. The damping properties of Al–BNNPs composites were evaluated by temperature dependent internal friction (TDIF) measurements. The obtained results are discussed based on structural analysis and the TDIF data.

  13. Fabrication, characterization, and mechanical properties of spark plasma sintered Al–BN nanoparticle composites

    International Nuclear Information System (INIS)

    Fabrication of high strength yet light and low cost composite materials with good mechanical properties at room and elevated temperatures is a challenge that metallurgy and materials science communities are facing for many years, and no “dream material” has been developed so far. The primary goal of this study was to fabricate, characterize, and to carry out tensile tests on Al-based composite materials strengthened with commercially-available BN nanoparticles (BNNPs). The composites were fabricated by spark plasma sintering (SPS) technique. The structures of powder mixtures and composite materials, as well as their fracture surfaces, were studied by scanning and transmission electron microscopy. The influence of BNNPs content (0.5, 1.5, 3, 4.5, 6, and 7.5 wt%) and holding times (5, 60, and 300 min) at 600 °C during SPS on the tensile strength was investigated. A maximum increase in strength was observed for Al-based composites with 4.5 wt% of BNNPs. The sample demonstrated a 50% increase in tensile strength compared with pristine Al. Although the tensile tests performed at 300 °C revealed that the tensile strength became 20% lower than the strength at room temperature, it was, however, still 75% higher compared with that of the pure Al at 300 °C. In addition, at 300 °C the Al–BNNPs composites demonstrated a much higher value of yield stress, about 115 MPa, which is 190% higher than that of pure Al at the same temperature. The damping properties of Al–BNNPs composites were evaluated by temperature dependent internal friction (TDIF) measurements. The obtained results are discussed based on structural analysis and the TDIF data

  14. Characterization of the regenerated cellulose films in ionic liquids and rheological properties of the solutions

    Energy Technology Data Exchange (ETDEWEB)

    Liu Zhen; Wang Hui [Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Li Zengxi, E-mail: zxli@home.ipe.ac.cn [Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Lu Xingmei; Zhang Xiangping [State Key Laboratory of Multiphase Complex System, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Zhang Suojiang, E-mail: sjzhang@home.ipe.ac.cn [State Key Laboratory of Multiphase Complex System, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Zhou Kebin [Graduate University of Chinese Academy of Sciences, Beijing 100049 (China)

    2011-07-15

    Highlights: {yields} The solubility can reach 13 wt% at 90 deg. C in ionic liquid of [bmim]Cl. {yields} Additive N-methylimidazole can minimize DP loss of the regenerated films. {yields} A mechanism of the dissolution of cellulose in [bmim]Cl was proposed. {yields} The ionic liquid of [bmim]Cl could be recycled. - Abstract: Dissolution and regeneration of cotton pulp using ionic liquids as solvent was investigated. The physicochemical properties of the regenerated cellulose films have been characterized by scanning electron microscopy, X-ray diffractometer, infrared spectrometric analyzer, differential scanning calorimeter, and thermogravimetric analysis instrument. The rheological properties of cotton pulp dissolved in ionic liquids have been investigated by steady shear and oscillatory shear measurements. The influences of experimental parameters, such as the reaction temperature, additives on the solubility and degree of polymerization (DP) of regenerated cellulose were also studied. The results show that 1-butyl-3-methylimidazolium chloride ([bmim]Cl) was a good solvent to dissolve cotton pulp and the solubility can reach 13 wt% at 90 deg. C, but the DP remarkably decreased from 510 to 180 within 7 h. It was found that additive N-methylimidazole can effectively minimize DP loss of the regenerated cellulose, which can attribute to the fact that in the mixture of [bmim]Cl and NMI solution, the {beta}-1,4-glycosidic bond of the cellulose chains cannot be broken because of the relative low concentration of Cl{sup -}. In the steady shear measurement, all the solutions show a shear thinning behavior at high shear rates. In addition, a mechanism of the dissolution of cellulose in [bmim]Cl was proposed.

  15. Characterization of the regenerated cellulose films in ionic liquids and rheological properties of the solutions

    International Nuclear Information System (INIS)

    Highlights: → The solubility can reach 13 wt% at 90 deg. C in ionic liquid of [bmim]Cl. → Additive N-methylimidazole can minimize DP loss of the regenerated films. → A mechanism of the dissolution of cellulose in [bmim]Cl was proposed. → The ionic liquid of [bmim]Cl could be recycled. - Abstract: Dissolution and regeneration of cotton pulp using ionic liquids as solvent was investigated. The physicochemical properties of the regenerated cellulose films have been characterized by scanning electron microscopy, X-ray diffractometer, infrared spectrometric analyzer, differential scanning calorimeter, and thermogravimetric analysis instrument. The rheological properties of cotton pulp dissolved in ionic liquids have been investigated by steady shear and oscillatory shear measurements. The influences of experimental parameters, such as the reaction temperature, additives on the solubility and degree of polymerization (DP) of regenerated cellulose were also studied. The results show that 1-butyl-3-methylimidazolium chloride ([bmim]Cl) was a good solvent to dissolve cotton pulp and the solubility can reach 13 wt% at 90 deg. C, but the DP remarkably decreased from 510 to 180 within 7 h. It was found that additive N-methylimidazole can effectively minimize DP loss of the regenerated cellulose, which can attribute to the fact that in the mixture of [bmim]Cl and NMI solution, the β-1,4-glycosidic bond of the cellulose chains cannot be broken because of the relative low concentration of Cl-. In the steady shear measurement, all the solutions show a shear thinning behavior at high shear rates. In addition, a mechanism of the dissolution of cellulose in [bmim]Cl was proposed.

  16. Synthesis, characterization, thermal and electrical properties of composite of polyaniline with cobaltmonoethanolamine complex

    Indian Academy of Sciences (India)

    Rehana Rasool; Kowsar Majid

    2014-08-01

    The present paper involves the synthesis of polyaniline (PANI) composite with cobaltmonoethanolamine [Co(mea)2(H2O)2Cl2] complex via in situ oxidative polymerization by ammonium persulphate. The complex has been synthesized by refluxing method. The composite has been subjected to UV–Visible spectra, FT–IR, X-ray diffraction, SEM and electrical conductivity characterization techniques. Thermal analysis has been done by using TG and DSC techniques. FT–IR absorption peaks confirm the insertion of complex in the backbone of PANI. SEM of the composite also supports its successful synthesis. The XRD of composite also shows crystalline structure hence, proving the successful synthesis of PANI. Thermal analysis shows enhanced thermal stability of polyaniline. In the present composite system, the polymerization of PANI with [Co(mea)2(H2O)2Cl2] complex causes strong interfacial interactions between PANI and [Co(mea)2(H2O)2Cl2] complex crystallites, also suggested by the FT–IR and XRD studies, thereby changing the molecular conformation of PANI from compact coil structure to an expanded coil-like structure. As a consequence, there is an enhancement in the conductivity of composite of PANI up to certain dopant concentration. The anticorrosive property of a coating of PANI/[Co(mea)2(H2O)2Cl2] composite on mild steel coupon in 3 M HNO3 was evaluated using weight loss measurement and compared with pure polyaniline coating. The said composite has shown anticorrosive property and can thus, act as a potent dopant for enhancing corrosion resistance of PANI coatings.

  17. Characterization of the Radiation Shielding Properties of US and Russian EVA Suits

    International Nuclear Information System (INIS)

    Reported herein are results from the Eril Research, Inc. (ERI) participation in the NASA Johnson Space Center sponsored study characterizing the radiation shielding properties of the two types of space suit that astronauts are wearing during the EVA on-orbit assembly of the International Space Station (ISS). Measurements using passive detectors were carried out to assess the shielding properties of the USEMU Suit and the Russian Orlan-M suit during irradiations of the suits and a tissue equivalent phantom to monoenergetic proton and electron beams at the Loma Linda University Medical Center (LLUMC). During irradiations of 6 MeV electrons and 60 MeV protons, absorbed dose as a function of depth was measured using TLDs exposed behind swatches of the two suit materials and inside the two EVA helmets. Considerable reduction in electron dose was measured behind all suit materials in exposures to 6MeV electrons. Slowing of the proton beam in the suit materials led to an increase in dose measured in exposures to 60 MeV protons. During 232 MeV proton irradiations, measurements were made with TLDs and CR-39 PNTDs at five organ locations inside a tissue equivalent phantom, exposed both with and without the two EVA suits. The EVA helmets produce a 13 to 27 percent reduction in total dose and a 0 to 25 percent reduction in dose equivalent when compared to measurements made in the phantom head alone. Differences in dose and dose equivalent between the suit and non-suit irradiations for the lower portions of the two EVA suits tended to be smaller. Proton-induced target fragmentation was found to be a significant source of increased dose equivalent, especially within the two EVA helmets, and average quality factor inside the EMU and Orlan-M helmets was 2 to 14 percent greater than that measured in the bare phantom head

  18. Monodisperse Co, Zn-Ferrite nanocrystals: Controlled synthesis, characterization and magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Sanjeev, E-mail: sanjeevkumar.dubey2@gmail.com [University of Petroleum and Energy Studies, Dehradun 248007 (India); Singh, Vaishali; Aggarwal, Saroj [School of Basic and Applied Sciences (India); Mandal, Uttam Kumar [University School of Chemical Technology, GGS Indraprastha University, Kashmere Gate, Delhi 110403 (India); Kotnala, R.K. [National Physical laboratory, New Delhi 110012 (India)

    2012-11-15

    Co{sub x}Zn{sub y}Fe{sub 3-x-y}O{sub 4} ferrite (x=1 to 0; y=0 to1) nanocrystals have been synthesized by reverse microemulsion method. The nanocrystals are then comprehensively characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Field emission transmission electron microscopy (FETEM), and magnetic properties were measured by using Vibrating sample magnetometer. X-ray analysis showed that all the crystals were cubic spinel. The lattice constant increased with the increase in Zn substitution. FETEM reveals that particle size varies in the range from 3 to 6 nm. As the concentration of Zn increases the magnetic behavior varies from ferromagnetic at y=0 and 0.2 to superparamagnetic to paramagnetic at y=1. The Curie temperature decreases with increasing concentration of Zn. - Highlights: Black-Right-Pointing-Pointer Reverse microemulsion route is a very facile route for synthesis of Co{sub x}Zn{sub y}Fe{sub 3-x-y}O{sub 4} ferrite and all particles synthesized by reverse microemulsion is in the range of 3-6 nm. Black-Right-Pointing-Pointer Presence of Zn changes the structural and magnetic properties of the Zn substituted CoFe{sub 2}O{sub 4}. Black-Right-Pointing-Pointer The lattice constant increases with the increase in Zn substitution. Black-Right-Pointing-Pointer The curie temperature decreases with Zn concentration appreciably. Black-Right-Pointing-Pointer Magnetic behavior varies from ferromagnetic at y=0, 0.2 to superparamagnetic to paramagnetic at y=1.

  19. Use of photoacoustic mid-infrared spectroscopy to characterize soil properties and soil organic matter stability

    Science.gov (United States)

    Peltre, Clement; Bruun, Sander; Du, Changwen; Stoumann Jensen, Lars

    2014-05-01

    The persistence of soil organic matter (SOM) is recognized as a major ecosystem property due to its key role in earth carbon cycling, soil quality and ecosystem services. SOM stability is typically studied using biological methods such as measuring CO2-C evolution from microbial decomposition of SOM during laboratory incubation or by physical or chemical fractionation methods, allowing the separation of a labile fraction of SOM. However these methods are time consuming and there is still a need for developing reliable techniques to characterize SOM stability, providing both quantitative measurements and qualitative information, in order to improve our understanding of the mechanisms controlling SOM persistence. Several spectroscopic techniques have been used to characterize and predict SOM stability, such as near infrared reflectance spectroscopy (NIRS) and diffuse reflectance mid-infrared spectroscopy (DRIFT). The latter allows a proper identification of spectral regions corresponding to vibrations of specific molecular or functional groups associated with SOM lability. However, reflectance spectroscopy for soil analyses raises some difficulties related to the low reflectance of soils, and to the high influence of particle size. In the last three decades, the progresses in microphone sensitivity dramatically increased the performance of photoacoustic Fourier transform mid-infrared spectroscopy (FTIR-PAS). This technique offers benefits over reflectance spectroscopy techniques, because particle size and the level of sample reflectance have little effect of on the PAS signal, since FTIR-PAS is a direct absorption technique. Despite its high potential for soil analysis, only a limited number of studies have so far applied FTIR-PAS for soil characterization and its potential for determining SOM degradability still needs to be investigated. The objective of this study was to assess the potential of FTIR-PAS for the characterization of SOM decomposability during

  20. Construction of Ru(II) Polypyridyl Based Macrocycles: Synthesis, Characterization, Electrochemical, Li+ Binding, Antitumour and Anti-HIV properties

    OpenAIRE

    Mishra, Lallan; Sinha, Ragini; Pandey, P. C.

    2001-01-01

    Some ruthenium (II) polypyridyl complexes with a bis-chalcone (obtained by the condensation of 3-methyl-thiophene-2-carboxaldehyde and 4-acetyl pyridine) have been synthesized and characterized spectroscopically (IR, NMR, UV/Vis), conductimetric, elemental analysis and FAB mass data. Their luminescent, redox and Li+ binding properties have been studied. The anti-HIV and antitumour activities have also been reported.

  1. Characterizing the Absorption Properties for Remote Sensing of Three Small Optically-Diverse South African Reservoirs

    Directory of Open Access Journals (Sweden)

    Mark William Matthews

    2013-09-01

    Full Text Available Characterizing the specific inherent optical properties (SIOPs of water constituents is fundamental to remote sensing applications. Therefore, this paper presents the absorption properties of phytoplankton, gelbstoff and tripton for three small, optically-diverse South African inland waters. The three reservoirs,  Hartbeespoort, Loskop and Theewaterskloof, are challenging for remote sensing, due to differences in phytoplankton assemblage and the considerable range of constituent concentrations. Relationships between the absorption properties and biogeophysical parameters, chlorophyll-a (chl-a, TChl (chl-a plus  phaeopigments,  seston,  minerals  and  tripton, are established. The value determined for the mass-specific tripton absorption coefficient at 442 nm, a∗ (442, ranges from 0.024 to 0.263 m2·g−1. The value of the TChl-specific phytoplankton absorption coefficient (a∗ was strongly influenced by phytoplankton species, size, accessory pigmentation and biomass. a∗ (440 ranged from 0.056 to 0.018 m2·mg−1 in oligotrophic to hypertrophic waters. The positive relationship between cell size and trophic state observed in open ocean waters was violated by significant small cyanobacterial populations. The phycocyanin-specific phytoplankton  absorption  at  620  nm,  a∗ (620, was determined as 0.007 m2·g−1 in a M. aeruginosa bloom. Chl-a was a better indicator of phytoplankton biomass than phycocyanin (PC in surface scums, due to reduced accessory pigment production. Absorption budgets demonstrate that monospecific blooms of M. aeruginosa and C. hirundinella may be treated as “cultures”, removing some complexities for remote sensing applications.   These results contribute toward a better understanding of IOPs and remote sensing applications in hypertrophic inland waters. However, the majority of the water is optically complex, requiring the usage of all the SIOPs derived here for remote sensing applications. The

  2. Characterization and pharmacological properties of a novel multifunctional Kunitz inhibitor from Erythrina velutina seeds.

    Directory of Open Access Journals (Sweden)

    Richele J A Machado

    Full Text Available Inhibitors of peptidases isolated from leguminous seeds have been studied for their pharmacological properties. The present study focused on purification, biochemical characterization and anti-inflammatory and anticoagulant evaluation of a novel Kunitz trypsin inhibitor from Erythrina velutina seeds (EvTI. Trypsin inhibitors were purified by ammonium sulfate (30-60%, fractionation followed by Trypsin-Sepharose affinity chromatography and reversed-phase high performance liquid chromatography. The purified inhibitor showed molecular mass of 19,210.48 Da. Furthermore, a second isoform with 19,228.16 Da was also observed. The inhibitor that showed highest trypsin specificity and enhanced recovery yield was named EvTI (P2 and was selected for further analysis. The EvTI peptide fragments, generated by trypsin and pepsin digestion, were further analyzed by MALDI-ToF-ToF mass spectrometry, allowing a partial primary structure elucidation. EvTI exhibited inhibitory activity against trypsin with IC50 of 2.2×10(-8 mol.L(-1 and constant inhibition (Ki of 1.0×10(-8 mol.L(-1, by a non-competitive mechanism. In addition to inhibit the activity of trypsin, EvTI also inhibited factor Xa and neutrophil elastase, but do not inhibit thrombin, chymotrypsin or peptidase 3. EvTI was investigated for its anti-inflammatory and anti-coagulant properties. Firstly, EvTI showed no cytotoxic effect on human peripheral blood cells. Nevertheless, the inhibitor was able to prolong the clotting time in a dose-dependent manner by using in vitro and in vivo models. Due to anti-inflammatory and anticoagulant EvTI properties, two sepsis models were here challenged. EvTI inhibited leukocyte migration and specifically acted by inhibiting TNF-α release and stimulating IFN-α and IL-12 synthesis. The data presented clearly contribute to a better understanding of the use of Kunitz inhibitors in sepsis as a bioactive agent capable of interfering in blood coagulation and inflammation.

  3. Synthesis, characterization and metal ion-sensing properties of two Schiff base derivatives.

    Science.gov (United States)

    Xu, Huihua; Tao, Xian; Li, Yueqin; Shen, Yingzhong; Wei, Yanhong

    2012-06-01

    Two new Schiff base derivatives {2,2'-diphenyl-N,N'-bis(2-pyridylmethylene)biphenyl-4,4'-diamine} (1) and {2,2'-diphenyl-N,N'-bis(salicylidene)biphenyl-4,4'-diamine} (2) were synthesized and characterized by means of elemental analysis, (1)H NMR, FT-IR, and standard spectroscopy techniques. The molecular structure of 2 has been determined by X-ray single crystal analysis. The analyses of fluorescence properties of the compounds revealed that 1 and 2 are both poorly fluorescent and display sensitive fluorescence responses to a panel of 24 monovalent, divalent, and trivalent metal ions in CH(3)CN-DMSO (9:1, v/v). Results with imine 1 showed that Fe(3+), Cu(2+), Zn(2+), Cd(2+), Mn(2+), Zr(4+), Hg(2+), Cr(2+), Pb(2+), Sn(2+), Bi(2+), Al(3+), Ce(3+), La(3+), Sm(3+), Gd(3+), Nd(3+), Eu(3+) and Dy(3+) yields red shifts in emission and increases in intensity. And the greatest spectral changes for imine 2 include enhancements in emission intensity coupled with red shifts (Zr(4+), Sn(2+), Al(3+) and Zn(2+)) and strong quenching (Fe(3+)). The fluorescence enhancement mechanism of 1 and 2 for metal ions is based on: (i) CN isomerization; (ii) chelation-enhanced fluorescence (CHEF) effect; and (iii) excited-state intra/intermolecular proton transfer (ESPT). PMID:22387686

  4. Elastin-like recombinamer catalyst-free click gels: characterization of poroelastic and intrinsic viscoelastic properties.

    Science.gov (United States)

    González de Torre, Israel; Santos, Mercedes; Quintanilla, Luis; Testera, Ana; Alonso, Matilde; Rodríguez Cabello, José Carlos

    2014-06-01

    Elastin-like recombinamer catalyst-free click gels (ELR-CFCGs) have been prepared and characterized by modifying both a structural ELR (VKVx24) and a biofunctionalized ELR-bearing RGD cell-adhesion sequence (HRGD6) to bear the reactive groups needed to form hydrogels via a click reaction. Prior to formation of the ELR-CFCGs, azide-bearing and cyclooctyne-modified ELRs were also synthesized. Subsequent covalent crosslinking was based on the reaction between these azide and cyclooctyne groups, which takes place under physiological conditions and without the need for a catalyst. The correlation among SEM micrographs, porosity, swelling ratio, and rheological measurements have been carried out. The storage and loss moduli at 1Hz are in the range 1-10kPa and 100-1000Pa, respectively. The linear dependence of |G∗| on f(½) and the peak value of tan δ were considered to be consistent with a poroelastic mechanism dominating the frequency range 0.3-70Hz. The discrete relaxation spectrum was obtained from stress relaxation measurements (t>5s). The good fit of the relaxation modulus to decrease exponential functions suggests that an intrinsic viscoelastic mechanism dominates the transients. Several recombinamer concentrations and temperatures were tested to obtain gels with fully tuneable properties that could find applications in the biomedical field. PMID:24530853

  5. Dissimilar friction welding of 6061-T6 aluminum and AISI 1018 steel: Properties and microstructural characterization

    International Nuclear Information System (INIS)

    Joining of dissimilar materials is of increasing interest for a wide range of industrial applications. The automotive industry, in particular, views dissimilar materials joining as a gateway for the implementation of lightweight materials. Specifically, the introduction of aluminum alloy parts into a steel car body requires the development of reliable, efficient and economic joining processes. Since aluminum and steel demonstrate different physical, mechanical and metallurgical properties, identification of proper welding processes and practices can be problematic. In this work, inertia friction welding has been used to create joints between a 6061-T6 aluminum alloy and a AISI 1018 steel using various parameters. The joints were evaluated by mechanical testing and metallurgical analysis. Microstructural analyses were done using metallography, microhardness testing, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray elemental mapping, focused ion beam (FIB) with ultra high resolution SEM and transmission electron microscopy (TEM) in TEM and STEM modes. Results of these analysis first suggested that joint strengths on the order of 250 MPa could be achieved. In addition, failures were seen in the plasticized layer on the aluminum side of the joint. Further, bond lines were characterized by a thin layer of formed Al-Fe intermetallic. This intermetallic layer averaged roughly 250 nm thick and compositionally appears related to the FeAl and Fe2Al5 phases.

  6. MnWO{sub 4} nanocapsules: Synthesis, characterization and its electrochemical sensing property

    Energy Technology Data Exchange (ETDEWEB)

    Muthamizh, Selvamani; Suresh, Ranganathan; Giribabu, Krishnamoorthy; Manigandan, Ramadoss; Praveen Kumar, Sivakumar; Munusamy, Settu; Narayanan, Vengidusamy, E-mail: vnnara@yahoo.co.in

    2015-01-15

    Highlights: • Synthesis of MnWO{sub 4} nanocapsules without use of any other external reagent. • High crystalline MnWO{sub 4} was obtained with phase purity. • Electrochemical sensing platform based on MnWO{sub 4} for sensing quercetin. • Micromolar detection ability of MnWO{sub 4} modified GCE. - Abstract: Manganese tungstate (MnWO{sub 4}) was synthesized by surfactant free precipitation method. MnWO{sub 4} was characterized by using various spectroscopic techniques. The phase, crystalline nature and the morphological analysis were carried out using XRD, scanning electron microscopy (SEM), and high resolution transmission electron microscopy (HR-TEM). Further, FT-IR, Raman, and DRS-UV–Vis spectral analysis were carried out in order to ascertain the optical property and the presence of functional groups. From the analysis, the morphology of the MnWO{sub 4} was observed to be in capsules with breadth and thickness were in nm range. The oxidation state of tungsten (W), and manganese (Mn) were investigated using X-ray photo electron spectroscopy (XPS) and electron paramagnetic resonance spectroscopy (EPR). The synthesized MnWO{sub 4} nanocapsules were used to modify glassy carbon electrode (GCE) to detect quercetin.

  7. Synthesis of an amphiphilic rhodamine derivative and characterization of its solution and thin film properties

    International Nuclear Information System (INIS)

    Here we present characterization of solution and thin film properties of Lissamine rhodamine B sulfonyl didodecyl amine (LRSD), an amphiphilic derivative of rhodamine. LRSD was synthesized by functionalizing Lissamine rhodamine B sulfonyl chloride (LRSC) with didodecylamine via a straightforward sulfonylation reaction. LRSD's long alkane chains make it highly soluble in chloroform, with a marked increase in brightness compared to the starting material. LRSD is shown to form well-defined robust micelles in water, without the addition of a co-surfactant and stable monolayers at the air–water interface. The greater lipophilicity of LRSD also enables doping into non-polar polymeric host matrices such as polystyrene with less aggregation and hence higher fluorescence quantum yield than LRSC or even rhodamine B. The monolayers of LRSD were prepared via Langmuir–Blodgett deposition and showed shifts in the photoluminescence peak from 575 nm to 595 nm, as the surface pressure is varied from 3 mN/m to 11 mN/m. - Highlights: • Lissamine rhodamine B sulfonyl didodecyl amine (LRSD) is soluble in chloroform. • LRSD shows robust quantum yield in solution and as a dopant in thin film. • LRSD is an amphiphilic rhodamine dye that forms compact fluorescent micelles. • LRSD forms a stable isotherm when spread at the air–water interface

  8. Synthesis, characterization and electrical properties of visible-light-driven Pt-ZnO/CNT

    Indian Academy of Sciences (India)

    M Mujahid

    2015-08-01

    This paper deals with synthesis of ZnO doped with different concentrations of platinum (Pt) and its deposition on the surface of multi-walled carbon nanotube (MWCNT). The synthesized nanocomposite material was characterized by standard analytical techniques like X-ray diffraction (XRD), UV–vis spectroscopy, scanning electron microscopy, transmission electron microscopy and energy-dispersive spectroscopy. The XRD analysis confirms two things; first, synthesized nanocomposite shows no impurity peaks indicating products being crystalline in nature, second, the phase structure of composite remains unchanged during doping of Pt into ZnO crystal. Results indicate that the incorporation of dopant into ZnO coated on the surface of MWCNT was found to shift the fundamental absorption edge towards the longer wavelength side. The impedance analysis was carried out to distinguish between the grain and grain boundary contributions to the system. The dielectric property was strongly affected by increasing the dopant concentration. The dielectric constant () and dielectric loss (tan ) factors decrease with the increase in frequency only upto a certain limit. The a.c. conductivity also increases with the increase in frequency.

  9. Structural characterization and emulsifying properties of polysaccharides of Acacia mearnsii de Wild gum.

    Science.gov (United States)

    Grein, Aline; da Silva, Bruno C; Wendel, Cinthia F; Tischer, Cesar A; Sierakowski, Maria Rita; Moura, Angela B Dewes; Iacomini, Marcello; Gorin, Philip A J; Simas-Tosin, Fernanda F; Riegel-Vidotti, Izabel C

    2013-01-30

    Polysaccharides (GNF) from Acacia mearnsii de Wild gum exudates, collected from trees growing in the south of Brazil, were characterized ((13)C and HSQC NMR, GC-MS, colorimetric assays). A commercial gum arabic (GAC) was analyzed similarly and compared with GNF. There were differences, consistent with distinct behavior in tensiometry tests and as emulsion stabilizer. GNF had a higher protein content than GAC, with small differences in the monosaccharide composition, the greater one being the lower uronic acid content of GNF (4%), compared with GAC (17%). GNF had a much broader molecular mass distribution, M(w)/M(n), and a lower M(w). GNF was more efficient in lowering the surface tension of water and saline solutions and was more efficient in emulsifying castor oil droplets. Results were discussed taking into account structural and molecular differences between the studied gums. It was concluded that polysaccharides from A. mearnsii de Wild are candidates as substitutes of currently commercialized arabic gums (Acacia senegal and Acacia seyal) having, depending on their application, improved properties. PMID:23218300

  10. Synthesis, Characterization and Properties of CeO2-doped TiO2 Composite Nanocrystals

    Directory of Open Access Journals (Sweden)

    Oman ZUAS

    2013-12-01

    Full Text Available Pure TiO2 and CeO2-doped TiO2 (3 % CeO2-97 %TiO2 composite nanocrystals were synthesized via co-precipitation method and characterized using TGA, XRD, FTIR, DR-UV-vis and TEM. The XRD data revealed that the phase structure of the synthesized samples was mainly in pure anatase having crystallite size in the range of 7 nm – 11 nm. Spherical shapes with moderate aggregation of the crystal particles were observed under the TEM observation. The presence of the CeO2 at TiO2 site has not only affected morphologically but also induced the electronic property of the TiO2 by lowering the band gap energy from 3.29 eV (Eg-Ti to 3.15 eV (Eg-CeTi. Performance evaluation of the synthesized samples showed that both samples have a strong adsorption capacity toward Congo red (CR dye in aqueous solution at room temperature experiment, where  the capacity of the CeTi was higher than the Ti sample. Based on DR-UV data, the synthesized samples obtained in this study may also become promising catalysts for photo-assisted removal of synthetic dye in aqueous solution. DOI: http://dx.doi.org/10.5755/j01.ms.19.4.2732

  11. Characterization and Catalytic Properties of a Rapidly Quenched Ni-RE-P-AL Catalyst

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A Ni-RE-P-AL catalyst prepared by alkaline extraction of a rapidly quenched Ni-RE-P-AL alloy was characterized by means of ICP,BET,XRD,ZPS and TEM.The results show that the rapidly quenched Ni-RE-P-AL alloy contained less crystalline AL3Ni than AL-Ni alloy.After alkaline extraction,most of Al in the Ni-RE-P-AL alloy was leached out and the resulted Ni-RE-P-AL catalyst presented a spone structure similar to Raney Ni.Although Crystalline Ni is the major phase in the Ni-RE-P-AL catalyst and Raney Ni,amorphous Ni-P phase has been detected in the Ni-RE-P-AL catalyst.Studies on catalytic hydrogenation of toluene,phenyl ethylene,acetylene benzene,nitrobenzene,cyclohexanone and adiponitrile in liquid phase showed that the activity and selectivity of this Ni-RE-P-AL catalyst are superior to those of Raney Ni,especially at low temperatures.The amorphous phase is considered to be responsible for its superior catalytic properties.

  12. The chemical properties and microbial community characterization of the thermophilic microaerobic pretreatment process.

    Science.gov (United States)

    Fu, Shan-Fei; He, Shuai; Shi, Xiao-Shuang; Katukuri, Naveen Reddy; Dai, Meng; Guo, Rong-Bo

    2015-12-01

    Thermophilic microaerobic pretreatment (TMP) was recently reported as an efficient pretreatment method of anaerobic digestion (AD). In this study, the chemical properties and microbial community were characterized to reveal how TMP working. Compared with thermophilic treatment under anaerobic condition (TMP0), cellulase activity obviously improved under microaerobic condition (TMP1), which was 10.9-49.0% higher than that of TMP0. Reducing sugar, SCOD and VFAs concentrations of TMP1 were 2.6-8.9%, 1.8-4.8% and 13.8-24% higher than those of TMP0, respectively. TMP gave obvious rise to phylum Firmicutes, which associated with extracellular enzymes production. The proportion of class Bacilli (belongs to phylum Firmicutes and mainly acts during hydrolysis) in TMP1 was 124.89% higher than that of TMP0, which reflected the greater hydrolytic ability under microaerobic condition. The improved abundance of phylum Firmicutes (especially class Bacilli, order Bacillales) under microaerobic condition could be the fundamental reason for the improved AD performance of thermophilic microaerobic pretreated corn straw. PMID:26433149

  13. Montmorillonite/graphene oxide/chitosan composite: Synthesis, characterization and properties.

    Science.gov (United States)

    Yadav, Mithilesh; Ahmad, Sharif

    2015-08-01

    The present work reports the successful preparation, thermal and mechanical characterization of high performance films of Na(+) montmorillonite (MMT)/graphene oxide (GO)/chitosan (CS) composite using simple solution mixing evaporation method. The formations of films were verified by Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman spectroscopy. The thermal stability and mechanical properties of these films were investigated by thermogravimetric analysis (TGA) and mechanical testing (Instron 8871). The results obtained from these studies revealed that the composites of chitosan, MMT, and graphene oxide were homogeneous in nature. A synergistic effect of MMT and GO reinforcing on chitosan matrix was observed for the first time, in case of 5 wt.% MMT and 1 wt.% GO. The tensile strength of (5 wt.%) MMT/(1 wt.%) GO/CS composite was formed 9±0.23% and 27±0.25% higher than that of the (1 wt.%) GO/CS composite and chitosan, respectively. PMID:26047900

  14. Controllable assembly, characterization and catalytic properties of a new Strandberg-type organophosphotungstate.

    Science.gov (United States)

    Ma, Hong-Xin; Du, Jing; Zhu, Zai-Ming; Lu, Ting; Su, Fang; Zhang, Lan-Cui

    2016-01-28

    Using phenylphosphonic acid, simple tungstate and copper(ii) compounds as starting materials, an organic-inorganic hybrid Strandberg-type organophosphotungstate, {[(Cu(H2O)(μ-bipy))2(C6H5PO3)2W5O15]}n (bipy = 4,4'-bipyridyl) (1), was assembled successfully under hydrothermal conditions and characterized by physico-chemical and spectroscopic methods. Compound 1 represents the first example of a transition metal complex modified organophosphotungstate cluster. In the crystal structure of compound 1, the polymeric 1-D {Cu-bipy}n chains are interconnected by [(C6H5PO3)2W5O15](4-) (abbreviated as {(C6H5P)2W5}) units into a 3-D framework. A hollow Keggin isopolytungstate [H2W12O40](6-) ({W12})-Cu(ii) coordination polymer, {[Cu(bipy)2((μ-bipy)Cu(bipy))2(H2W12O40)]·12H2O}n (2), was obtained at different molar ratios of the starting materials and pH. The two Cu(ii) coordination polymers exhibit good acid-catalytic activity for the synthesis of cyclohexanone ethylene ketal. Their fluorescence properties were studied. PMID:26690720

  15. Synthesis, characterization and antibacterial properties of dihydroxy quaternary ammonium salts with long chain alkyl bromides.

    Science.gov (United States)

    Liu, Wen-Shuai; Wang, Chun-Hua; Sun, Ju-Feng; Hou, Gui-Ge; Wang, Yu-Peng; Qu, Rong-Jun

    2015-01-01

    Five N-methyl-N-R-N,N-bis(2-hydroxyethyl) ammonium bromides (R = -benzyl (chloride, BNQAS), -dodecyl (C12QAS), -tetradecyl (C14QAS), -hexadecyl (C16QAS), -octadecyl (C18QAS)) were prepared based on N-methyldiethanolamine (MDEA) and halohydrocarbon. Five QAS were characterized by FTIR, NMR, and MS. BNQAS, C12QAS, C14QAS, and C16QAS were confirmed by X-ray single-crystal diffraction. Their antibacterial properties indicated good antibacterial abilities against E. coli, S. aureus, B. subtilis, especially C12QAS with the best antibacterial ability (100% to E. coli, 95.65% to S. aureus, and 91.41% to B. subtilis). In addition, C12QAS also displayed the best antifungal activities than BNQAS and C18QAS against Cytospora mandshurica, Botryosphaeria ribis, Physalospora piricola, and Glomerella cingulata with the ratio of full marks. The strategy provides a facile way to design and develop new types of antibacterial drugs for application in preventing the fruit rot, especially apple. PMID:25215430

  16. Microstructure characterization and tensile properties of 18Cr–4Al-oxide dispersion strengthened ferritic steel

    Energy Technology Data Exchange (ETDEWEB)

    Li, Shaofu; Zhou, Zhangjian, E-mail: zhouzhj@mater.ustb.edu.cn; Li, Ming; Wang, Man; Zhang, Guangming

    2015-11-05

    A microstructural characterization was performed on an 18Cr–4Al oxide dispersion strengthened (ODS) ferritic steel using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found that the secondary phases in the 18Cr–4Al-ODS ferritic steel can be roughly divided into three categories according to their size-level: (1) micron-sized intermetallic σ and YAl phases; (2) submicron-sized precipitates consisting of TiN and AlN precipitates; (3) nano-sized Al{sub 2}O{sub 3} and Y–Ti–O/Y–Al–O complex oxide particles with diameters in a broad size range from several to dozens of nanometers. In addition, tensile testing results revealed that the 18Cr–4Al-ODS sample exhibited better tensile strength and ductility as compared with another commercial ODS steel with similar composition. - Graphical abstract: TEM BF micrographs of carbon extraction replicas of the as-heat treated 18Cr–4Al-ODS sample. - Highlights: • Various types of secondary phase precipitates were identified. • Two kinds of nano-sized particles (Y–Ti–O/Y–Al–O) were found in matrix. • Nano-sized oxide particles uniformly dispersed in matrix. • Correlation between secondary phases and tensile properties was discussed.

  17. Characterization of Water Extractable Arabinoxylans from a Spring Wheat Flour: Rheological Properties and Microstructure

    Directory of Open Access Journals (Sweden)

    Alma Campa-Mada

    2013-07-01

    Full Text Available In the present study water extractable arabinoxylans (WEAX from a Mexican spring wheat flour (cv. Tacupeto F2001 were isolated, characterized and gelled and the gel rheological properties and microstructure were investigated. These WEAX presented an arabinose to xylose ratio of 0.66, a ferulic acid and diferulic acid content of 0.526 and 0.036 µg/mg WEAX, respectively and a Fourier Transform Infra-Red (FT-IR spectrum typical of arabinoxylans. The intrinsic viscosity and viscosimetric molecular weight values for WEAX were 3.5 dL/g and 504 kDa, respectively. WEAX solution at 2% (w/v formed gels induced by a laccase as cross-linking agent. Cured WEAX gels registered storage (G’ and loss (G’’ modulus values of 31 and 5 Pa, respectively and a diferulic acid content of 0.12 µg/mg WEAX, only traces of triferulic acid were detected. Scanning electron microscopy analysis of the lyophilized WEAX gels showed that this material resembles that of an imperfect honeycomb.

  18. Structure/property (constitutive and dynamic strength/damage) characterization of additively manufactured 316L SS

    Science.gov (United States)

    Gray, G. T., III; Livescu, V.; Rigg, P. A.; Trujillo, C. P.; Cady, C. M.; Chen, S. R.; Carpenter, J. S.; Lienert, T. J.; Fensin, S.

    2015-09-01

    For additive manufacturing (AM), the certification and qualification paradigm needs to evolve as there exists no "ASTM-type" additive manufacturing certified process or AM-material produced specifications. Accordingly, utilization of AM materials to meet engineering applications requires quantification of the constitutive properties of these evolving materials in comparison to conventionally-manufactured metals and alloys. Cylinders of 316L SS were produced using a LENS MR-7 laser additive manufacturing system from Optomec (Albuquerque, NM) equipped with a 1kW Yb-fiber laser. The microstructure of the AM-316L SS is detailed in both the as-built condition and following heat-treatments designed to obtain full recrystallization. The constitutive behavior as a function of strain rate and temperature is presented and compared to that of nominal annealed wrought 316L SS plate. The dynamic damage evolution and failure response of all three materials was probed using flyer-plate impact driven spallation experiments at a peak stress of 4.5 GPa to examine incipient spallation response. The spall strength of AM-produced 316L SS was found to be very similar for the peak shock stress studied to that of annealed wrought or AM-316L SS following recrystallization. The damage evolution as a function of microstructure was characterized using optical metallography.

  19. Chemical characterization, antioxidant, anti-inflammatory and cytotoxic properties of bee venom collected in Northeast Portugal.

    Science.gov (United States)

    Sobral, Filipa; Sampaio, Andreia; Falcão, Soraia; Queiroz, Maria João R P; Calhelha, Ricardo C; Vilas-Boas, Miguel; Ferreira, Isabel C F R

    2016-08-01

    Bee venom (BV) or apitoxin is a complex mixture of substances with reported biological activity. In the present work, five bee venom samples obtained from Apis mellifera iberiensis from the Northeast Portugal (two different apiaries) were chemically characterized and evaluated for their antioxidant, anti-inflammatory and cytotoxic properties. The LC/DAD/ESI-MS(n) analysis of the samples showed that melittin was the most abundant compound, followed by phospholipase A2 and apamin. All the samples revealed antioxidant and anti-inflammatory activity but without a direct relation with any of the individual chemical components identified. The results highlight that there are specific concentrations (present in BV5) in which these compounds are more active. The BV samples showed similar cytotoxicity for all the tested tumour cell lines (MCF-7, NCI-H460, HeLa and HepG2), being MCF-7 and HeLa the most susceptible ones. Nevertheless, the studied samples seem to be suitable to treat breast, hepatocellular and cervical carcinoma because at the active concentrations, the samples were not toxic for non-tumour cells (PLP2). Regarding the non-small cell lung carcinoma, BV should be used under the toxic concentration for non-tumour cells. Overall, the present study corroborates the enormous bioactive potential of BV being the first report on samples from Portugal. PMID:27288930

  20. Tungstocobaltate-pillared layered double hydroxides: Preparation, characterization, magnetic and catalytic properties

    International Nuclear Information System (INIS)

    A new polyoxometalate anion-pillared layered double hydroxide (LDH) was prepared by aqueous ion exchange of a Mg-Al LDH precursor in nitrate form with the tungstocobaltate anions [CoW12O40]5-. The physicochemical properties of the product were characterized by the methods of powder X-ray diffraction, elemental analysis, infrared spectroscopy, thermogravimetric analysis and cyclic voltammetry. It was confirmed that [CoW12O40]5- was intercalated between the brucite-type layers of the LDHs without a change in the structure. Magnetic measurement shows the occurrence of antiferromagnetic interactions between the magnetic centers. The investigation of catalytic performance for this sample exhibits high activity for the oxidation of benzaldehyde by hydrogen peroxide. - Graphical abstract: A tungstocobaltate anion [CoW12O40]5- pillared layered double hydroxide (LDH) was prepared by aqueous ion exchange with a Mg-Al LDH precursor in nitrate form, demonstrating that [CoW12O40]5- was intercalated between the brucite-type layers of the LDHs without change in structure. Magnetic measurement shows the occurrence of antiferromagnetic interactions between the magnetic centers. The investigation of catalytic performance for this sample exhibits high activity for the oxidation of benzaldehyde by hydrogen peroxide

  1. Characterization of the mechanical properties of backpacks and their influence on the energetics of walking.

    Science.gov (United States)

    Foissac, Matthieu; Millet, Guillaume Y; Geyssant, André; Freychat, Philippe; Belli, Alain

    2009-01-19

    The objectives of the experiment were (i) to characterize the mechanical properties of backpacks and (ii) to study the influence of a flexible backpack on the energetics and kinematics of walking. Twelve subjects walked at different speeds on a treadmill with each of two backpacks loaded with 25% bodyweight, with either a rigid or a flexible link between the body attachment and the suspended loads. A single degree of freedom linear model of the link between the pack and the trunk was used to calculate the stiffness and damping coefficient of the two backpacks. The oxygen consumption (VO2) and the vertical acceleration of both the backpack and trunk were measured. The vertical excursion of the pack given by the model was significantly correlated with that actually measured (R=0.87, pbackpack can provide energetic benefits when its oscillations are nearly in phase with those of the trunk. However, any resonance effect can lead to a modified walking pattern and an increased metabolic cost. PMID:19062021

  2. Synthesis, characterization and optical properties of hybrid PVA–ZnO nanocomposite: A composition dependent study

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • ZnO nanoparticles were prepared by solution combustion method. • PVA–ZnO nanocomposites were synthesized by solution casting method. • Doped and undoped films were characterized using different techniques. • Red shift in optical band gap was observed in Nanocomposite films with respect to nano ZnO. • Photoluminescence intensity was found to be optimum for PVA–10 mol% ZnO nanocomposite film. - Abstract: Nanocomposites of poly vinyl alcohol (PVA) and ZnO have been synthesized using the solution casting technique for different concentrations of nano ZnO powder prepared by low temperature solution combustion method. The formation of polymer nanocomposite and changes in the structural and micro structural properties of the materials were investigated by X-ray diffraction, Energy dispersive X ray spectroscopy and optical microscopy techniques (FTIR and UV–Visible). The surface morphology of PVA–ZnO nanocomposite films were elucidated using Scanning Electron Microscopy. The optical absorption spectrum of nano ZnO shows blue shift in the optical band gap energy with respect to characteristic bulk ZnO at room temperature, whereas PVA–ZnO hybrid films show red shift with respect to nano ZnO. The photoluminescence studies show that the intensity of the blue emission (470 nm) varies with change in concentration of ZnO with an optimum intensity observed at 10 mol% of ZnO

  3. Optical properties and electrochromic characterization of sol-gel deposited ceria films

    Energy Technology Data Exchange (ETDEWEB)

    Oezer, N. [Department of Materials Science and Mineral Engineering, University of California, 94720-1760 Berkeley, CA (United States)

    2001-06-01

    Ceria (CeO{sub 2}) films were deposited by the sol-gel spin coating process and optical and electrochromic properties have been investigated. Ceria coating solutions were prepared using cerium ammonium nitrate and ethanol. The films were characterized by X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), UV-visible (UV-Vis) spectroscopy and cyclic voltammetry. XRD analysis of the films showed that they had a cerianite structure for heat treatment temperatures at or above 450C. XPS examinations show that the film stoichiometry was CeO{sub 2}. The SEM examinations showed that the surface texture was very uniform and homogeneous. Optical constants of the films were calculated from transmittance (T) spectra using optical spectrometer in the wavelength range of 300-900nm. The refractive index (n), and extinction coefficient (k) values were n=1.82{+-}0.01 and k=0.02{+-}0.002 at 550nm, respectively. The optical bandgap (E{sub g}) of crystalline cerium oxide film was 3.1{+-}0.003eV. The electrochemical behavior investigated in 0.5M LiClO{sub 4} propylene carbonate (PC) electrolyte. Cyclic voltammetry showed a reversible electrochemical insertion or extraction of the Li{sup +} ions maintaining a high optical transmissivity. Spectroelectrochemistry showed that these films could be used as optically passive counter-electrode in transmissive electrochromic devices.

  4. Synthesis, Characterization and Properties of CeO2-doped TiO2 Composite Nanocrystals

    Directory of Open Access Journals (Sweden)

    Oman ZUAS

    2013-12-01

    Full Text Available Pure TiO2 and CeO2-doped TiO2 (3 % CeO2-97 %TiO2 composite nanocrystals were synthesized via co-precipitation method and characterized using TGA, XRD, FTIR, DR-UV-vis and TEM. The XRD data revealed that the phase structure of the synthesized samples was mainly in pure anatase having crystallite size in the range of 7 nm – 11 nm. Spherical shapes with moderate aggregation of the crystal particles were observed under the TEM observation. The presence of the CeO2 at TiO2 site has not only affected morphologically but also induced the electronic property of the TiO2 by lowering the band gap energy from 3.29 eV (Eg-Ti to 3.15 eV (Eg-CeTi. Performance evaluation of the synthesized samples showed that both samples have a strong adsorption capacity toward Congo red (CR dye in aqueous solution at room temperature experiment, where the capacity of the CeTi was higher than the Ti sample. Based on DR-UV data, the synthesized samples obtained in this study may also become promising catalysts for photo-assisted removal of synthetic dye in aqueous solution. DOI: http://dx.doi.org/10.5755/j01.ms.19.4.2732

  5. Characterization of starch morphology, composition, physicochemi-cal properties and gene expressions in oat

    Institute of Scientific and Technical Information of China (English)

    Zheng Ke; Zheng You-liang; Jiang Qian-tao; Wei Long; Zhang Xiao-wei; Ma Jian; Chen guo-yue; Wei Yu-ming; Mitchell Fetch Jennifer; Lu Zhen-xiang

    2015-01-01

    abstract Starch is the major carbohydrate in oat (Avena sativaL.) and starch formation requires the coordinated actions of several synthesis enzymes. In this study, the granule morphology, composition and physicochemical properties of oat starch, as wel as the expressions of starch synthesis genes were investigated during oat endosperm development. Under the scanning electron microscopy (SEM), we observed that the unique compound granules were developed in oat endosperms at 10 days post anthesis (DPA) and then fragmented into irregular or polygonal simple granules from 12 DPA until seed maturity. The amylose content, branch chain length of degree of polymerization (DP=13–24), gelatinization temperature and percentage of retrogradation were gradualy increased during the endosperm development; whereas the distribution of short chains (DP=6–12) were gradualy decreased. The relative expressions of 4 classes of 13 starch synthesis genes characterized in this study indicated that three expression pattern groups were signiifcantly different among gene classes as wel as among varied isoforms, in which the ifrst group of starch synthesis genes may play a key role on the initiation of starch synthesis in oat endosperms.

  6. Characterization and Properties of Micro-arc Composite Ceramic Coatings on Magnesium Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Long; Jiang, Bailing; Ge, Yanfeng; Nyberg, Eric A.; Liu, Ming

    2013-05-21

    Magnesium alloys are of growing interest for many industrial applications due to their favorable strength-to-weight ratio and excellent cast ability. However, one of the limiting factors in the use of magnesium on production vehicles is its poor corrosion resistance. Micro-arc Composite Ceramic (MCC) coatings on AZ91D magnesium alloys were prepared in combination with Micro-arc Oxidation (MAO) and electrophoresis technologies. The microstructure, corrosion resistance, abrasion resistance, stone impact resistance, thermal shock resistance and adhesion of MCC coating were studied, respectively. The surface and cross-section morphologies of MAO and MCC coating showed that the outer organic coating filled the holes on the surface of the MAO coating. It acted as a shelter on the MAO coating surface when the MCC coatings were exposed to corrosive environments. The corrosion resistance of the MCC coating was characterized by a copper-accelerated acetic acid salt spray test. The testing results showed that the creep back from scribe lines was less than 1mm and completely fit the evaluation standard. The composite structure of the MCC coating vastly improved the corrosion resistance of Mg alloys. According to testing standards, the resistance to abrasion, stone impact resistance, thermal shock resistance and adhesion of MCC coatings completely met the evaluation standard requirements. The MCC coated AZ91D magnesium alloys possessed excellent properties; this is a promising corrosion and wear resistance surface treatment technology on magnesium alloys for production vehicles.

  7. Preliminary studies on the chemical characterization and antioxidant properties of acidic polysaccharides from Sargassum fusiforme

    Institute of Scientific and Technical Information of China (English)

    Jing ZHOU; Nan HU; Ya-lin WU; Yuan-jiang PAN; Cui-rong SUN

    2008-01-01

    In order to investigate the antioxidant properties of the polysaccharides from the brown alga Sargassum fusiforme, the crude polysaccharides from S.fusiforme (SFPS) were extracted in hot water, and the lipid peroxidation inhibition assay exhibited that SFPS possessed a potential antioxidant activity. Hence, two purely polymeric fractions, SFPS-1 and SFPS-2 were isolated by the column of DEAE (2-diethylaminoethanol)-Sepharose Fast Flow, with their molecular weights of 51.4 and 30.3 kDa determined by high performance gel permeation chromatography (HPGPC). They were preliminarily characterized using chemical analysis in combination of infrared (IR) and nuclear magnetic resonance (NMR) spectroscopies and found to contain large amounts of uronic acids and β-glycosidical linkages. The antioxidant activities of these two SFPS fractions were evaluated using superoxide and hydroxyl radical-scavenging assays. The results show that the antioxidant ability of SFPS-2 was higher than that of SFPS-1, probably correlating with the molecular weight and uronic acid content.

  8. Structure/property (constitutive and dynamic strength/damage characterization of additively manufactured 316L SS

    Directory of Open Access Journals (Sweden)

    Gray III G.T.

    2015-01-01

    Full Text Available For additive manufacturing (AM, the certification and qualification paradigm needs to evolve as there exists no “ASTM-type” additive manufacturing certified process or AM-material produced specifications. Accordingly, utilization of AM materials to meet engineering applications requires quantification of the constitutive properties of these evolving materials in comparison to conventionally-manufactured metals and alloys. Cylinders of 316L SS were produced using a LENS MR-7 laser additive manufacturing system from Optomec (Albuquerque, NM equipped with a 1kW Yb-fiber laser. The microstructure of the AM-316L SS is detailed in both the as-built condition and following heat-treatments designed to obtain full recrystallization. The constitutive behavior as a function of strain rate and temperature is presented and compared to that of nominal annealed wrought 316L SS plate. The dynamic damage evolution and failure response of all three materials was probed using flyer-plate impact driven spallation experiments at a peak stress of 4.5 GPa to examine incipient spallation response. The spall strength of AM-produced 316L SS was found to be very similar for the peak shock stress studied to that of annealed wrought or AM-316L SS following recrystallization. The damage evolution as a function of microstructure was characterized using optical metallography.

  9. Structural Characterization and Property Study on the Activated Alumina-activated Carbon Composite Material

    Institute of Scientific and Technical Information of China (English)

    CHEN Yan-Qing; WU Ren-Ping; YE Xian-Feng

    2012-01-01

    AlCl3,NH3·H2O,HNO3 and activated carbon were used as raw materials to prepare one new type of activated alumina-activated carbon composite material.The influence of heat treatment conditions on the structure and property of this material was discussed;The microstructures of the composite material were characterized by XRD,SEM,BET techniques;and its formaldehyde adsorption characteristic was also tested.The results showed that the optimal heat treatment temperature of the activated alumina-activated carbon composite material was 450 ℃,iodine adsorption value was 441.40 mg/g,compressive strength was 44 N,specific surface area was 360.07 m2/g,average pore size was 2.91 nm,and pore volume was 0.26 m3/g.According to the BET pore size distribution diagram,the composite material has dual-pore size distribution structure,the micro-pore distributes in the range of 0.6-1.7 nm,and the meso-pore in the range of 3.0-8.0 nm.The formaldehyde adsorption effect of the activated alumina-activated carbon composite material was excellent,much better than that of the pure activated carbon or activated alumina,and its saturated adsorption capacity was 284.19 mg/g.

  10. Characterization and antimicrobial properties of cotton fabric loaded with green synthesized silver nanoparticles.

    Science.gov (United States)

    Ibrahim, Haytham M M; Hassan, Mahmoud S

    2016-10-20

    In the present study, antimicrobial formulations, based on silver nanoparticles (AgNPs) and butyl acrylate binder, were prepared and applied to a cotton fabric, followed by gamma-radiation or thermal curing, to protect it against the undesirable microbial effects. AgNPs were prepared by a biological method, using the biomass filtrate of fungus Alternaria alternata. Nanoparticles were characterized by UV-vis spectroscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, and dynamic light scattering. Besides, the thermal stability, surface morphology, color strength, and mechanical properties of treated fabric were investigated. Treated cotton fabric showed good quantitative and qualitative antimicrobial activity; the bacterial reduction efficiency reached ∼100% for Escherichia coli and Staphylococcus aureus. They revealed excellent resistance to biodegradation caused by soil microflora. Moreover, they exhibited high durability of the attained antimicrobial activities, even after 20 washing cycles; where they achieved 99.1% and 98.7% reduction of E. coli and S. aureus bacterial counts, respectively. PMID:27474632

  11. Preparation, characterization and magnetic properties of the BaFe12O19 @ chitosan composites

    Science.gov (United States)

    Li, Lei; Zhang, Zunju; Xie, Yu; Zhao, Jie

    2016-07-01

    The BaFe12O19 @ chitosan composites are synthesized by the crosslinking reaction through chitosan and glutaraldehyde onto the surface of BaFe12O19. The structures of the samples were characterized by Fourier transform infrared spectroscopy and X-ray diffraction. The shape and size were observed by scanning electron microscopy and transmission electron microscopy. These results showed that chitosan has been decorated onto the surface of BaFe12O19, and the chitosan-glutaraldehyde Schiff-base composites have also been formed within the chitosan layers. Then, the magnetic properties of the samples were tested with the vibrating sample magnetometer. The magnetic saturation (MS), residual magnetization (Mr) and coercive force (Hc) values of the BaFe12O19 @ chitosan Schiff-base composite have achieved 44.94 emu/g, 27.82 emu/g and 3580.7 Oe, respectively. Compared with single BaFe12O19, the MS, and Mr of the BaFe12O19 @ chitosan composites decreases 12.31 emu/g and 8.58 emu/g, respectively. Finally, based on the experimental results, the probable formation mechanism of this composite has been investigated.

  12. Growth, characterization and electrochemical properties of hierarchical CuO nanostructures for supercapacitor applications

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Hierarchical CuO nanostructures were grown on Cu foil. • Monoclinic phase of CuO was grown. • XPS analysis revealed the presence of Cu(2p3/2) and Cu(2p1/2) on the surfaces. • Specific capacitance of 94 F/g was achieved for the CuO using cyclic voltammetry. • Impedance spectra show their pseudo capacitor applications. - Abstract: In this paper, we have investigated the electrochemical properties of hierarchical CuO nanostructures for pseudo-supercapacitor device applications. Moreover, the CuO nanostructures were formed on Cu substrate by in situ crystallization process. The as-grown CuO nanostructures were characterized using X-ray diffraction (XRD), Fourier transform-infra red spectroscopy (FT-IR), X-ray photoelectron spectroscopy and field emission-scanning electron microscope (FE-SEM) analysis. The XRD and FT-IR analysis confirm the formation of monoclinic CuO nanostructures. FE-SEM analysis shows the formation of leave like hierarchical structures of CuO with high uniformity and controlled density. The electrochemical analysis such as cyclic voltammetry and electrochemical impedance spectroscopy studies confirms the pseudo-capacitive behavior of the CuO nanostructures. Our experimental results suggest that CuO nanostructures will create promising applications of CuO toward pseudo-supercapacitors

  13. Highly crystalline manganese selenide nanorods: Synthesis, characterization, and microwave absorption properties

    International Nuclear Information System (INIS)

    Highlights: ► High-quality MnSe2 nanorods via facile solvothermal method. ► MnSe2 nanorods with different aspect radio can be prepared with different amount of PVP. ► MnSe2 nanorods have great potential application as microwave absorber. - Abstract: Highly crystalline manganese diselenide (MnSe2) nanorods were synthesized via a facile solvothermal reaction with polyvinylpyrrolidone as a capping agent. The size, morphology, structure as well as phase purity were characterized by scanning electron microscopy, transmission electron microscopy, electron energy loss spectroscopy, powder X-ray diffraction, and energy-dispersive X-ray spectroscopy. All the results demonstrated that the as-synthesized MnSe2 nanorods grow along [2 0 0] axis and have high crystallization degree. Moreover, the aspect ratio of the MnSe2 nanorods ranging from ∼15 to ∼70 can be tuned by simply changing the amount of polyvinylpyrrolidone. Besides, the volume ratio of N,N-dimethylformamide to deionized water has critical influence on the morphology and composition of the products. Moreover, the microwave absorption properties of the MnSe2 nanorods were investigated. All the studies indicate that the MnSe2 nanorods might have potential applications as promising microwave absorbing materials.

  14. The inclined impact test, an efficient method to characterize coatings' cohesion and adhesion properties

    International Nuclear Information System (INIS)

    The impact test, supported by its finite elements method (FEM) simulation, has been successfully used to characterize the fatigue performance of coatings. In this test, the load is exercised perpendicularly to the coated surface by a cemented carbides ball. In the inclined impact test, the successive impacts are applied on an inclined surface. In this way, the coated surfaces are loaded vertically and tangentially simultaneously. The coating fatigue failure modes were classified by means of scanning electron microscopy (SEM) observations and energy dispersive X-ray spectroscopy microanalyses. The experimental method is supported by a developed FEM simulation, which considers the mechanical elastic-plastic properties of the coating and of the substrate, as well as of the ball indenter during the impact test, thus enabling the elucidation of the coating failure modes. In this way, critical equivalent stresses were determined and the coating cohesive and adhesive impact performance was systematically investigated. The inclined impact test implies a new reference to the prediction of the coatings' cohesive and adhesive failure, managing to approach loading directions for a variety of coated surfaces in different applications. Examples for an efficient use of this test are presented and a characteristic magnitude, the coating impact adhesion (CIA), is introduced

  15. Synthesis and characterization of Ag nanoparticles decorated mesoporous sintered activated carbon with antibacterial and adsorptive properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wenxia; Xiao, Kaijun, E-mail: fekjxiao@scut.edu.cn; He, Tinglin; Zhu, Liang, E-mail: zhuliang@scut.edu.cn

    2015-10-25

    In this study, the sliver nanoparticles (AgNPs) immobilized on the sintered activated carbon (Ag/SAC) were synthesized by the ultrasonic-assisted impregnation method and were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD) and nitrogen adsorption. SEM showed that the AgNPs were well embedded in the SAC and immersion time had an important influence on final morphologies of AgNPs. Longer immersing duration caused significant aggregation of the AgNPs. The XRD data revealed that the successful synthesis of AgNPs on the SAC and immobilizing AgNPs on sintered active carbon did not change the crystalline degree of SAC. Texture characteristics were determined by analysis of the N{sub 2}/77 K isotherms. The minimum inhibitory concentration (MIC) of Ag/SAC against Escherichia coli (DH5α) and Staphyloccocus aureus (ATCC 29213) was evaluated by a broth dilution method. MICs such as 5 mg/L (against E. coli) and 10 mg/L (against S. aureus) suggest that Ag/SAC have predominant antibacterial activity compared to active carbon. - Highlights: • Sintered active carbon (SAC) was coated with Ag via a facile approach. • The Ag/SAC exhibit good adsorption properties and excellent antibacterial effects. • The Ag/SAC was durable and stable in the application of water purification.

  16. Synthesis, structure characterization, and ion exchange properties of a novel open-framework ecomaterial silicotitanate

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A novel open-framework ecomaterial silicotitanate (Na4Ti4Si3O10) was synthesized by a combination of solgel and hydrothermal methods. The investigation on ion exchange properties shows that Na4Ti4Si3O10 exhibits high adsorption for cesium, i.e., Kd is as high as 60 000 mL/g in neutral solution. The crystal structure of Na4Ti4Si3O10 was characterized by X-ray diffraction (XRD), scanning electronic microscope (SEM), transmission electron microscope (TEM),Raman spectrum, differential thermal and thermogravimetric analysis (DTA/TGA), inductively coupled plasma (ICP),and X fluorescence analysis. The compound is tetragonal, P42, a = b = 0.781 10 nm, c = 1.196 45 nm, a =β = γ = 90°, Z= 4, and Ra = 0.041; Na4Ti4Si3O10 has a three dimensional framework consisting of Ti-O octahedral clusters and Si-O tetrahedra. The results show that Na4Ti4Si3O10 has good chemical stability, thermal stability, and high cesium ion exchange capacity in the whole pH range.

  17. Obtention of graft copolymers by ionizing radiation, characterization and study of hemo-compatible properties

    International Nuclear Information System (INIS)

    The present work had as objectives the obtention and characterization of grafting copolymers by radiation induced polymerization and the study of its hemo compatible properties. The relationship between grafting conditions and anti-trombogenicity was examined for the purpose of clearing the necessity of controlling grafting conditions to enhance the copolymers blood compatibility. Two methods were chosen to accomplish the irradiation: mutual and pre-irradiation (peroxidation) of the films in 6O Co source and electron beam accelerator. Primarily grafting parameters were studied in the systems of the monomers N, N-dimethyl acrylamide (DMAA) and acrylic acid (AA) with the polymeric films: poly (tetrafluoroethylene) (PTFE), poly (ethylene-co-tetrafluoroethylene) (PETFE), low density polyethylene (LDPE) and poly (vinyl chloride) (PVC). The simultaneous irradiation was effective in the polymerization of all the substrates above mentioned, although the peroxidation method has given better results for PETFE-DMAA, LDPE-g-DMAA, LDPE-g-AA and PVC-g-AA. In the system AA/LDPE and AA/PVC the homo polymerization was controlled by the addition of the comonomer N, N-dimethyl acrylic acid (DMA). As for the grafting parameters, low dose rate and low irradiation dose, showed to be very effective for the graftability of DMAA and AA on the substrates. (author). 129 refs, 51 figs, 7 tabs

  18. ZnCr2O4 Nanoparticles: Facile Synthesis, Characterization, and Photocatalytic Properties

    Science.gov (United States)

    Mousavi, Zahra; Soofivand, Faezeh; Esmaeili-Zare, Mahdiyeh; Salavati-Niasari, Masoud; Bagheri, Samira

    2016-02-01

    In this work, zinc chromite (ZnCr2O4) nanostructures have been synthesized through co-precipitation method. The effect of various parameters such as alkaline agent, pH value, and capping agent type was investigated on purity, particle size and morphology of samples. It was found that particle size and morphology of the products could be greatly influenced via these parameters. The synthesized products were characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), fourier transform infrared (FT-IR) spectra, X-ray energy dispersive spectroscopy (EDS), photoluminescence (PL) spectroscopy, diffuse reflectance spectroscopy (DRS) and vibrating sample magnetometry (VSM). The superhydrophilicity of the calcined oxides was investigated by wetting experiments and a sessile drop technique which carried out at room temperature in air to determine the surface and interfacial interactions. Furthermore, the photocatalytic activity of ZnCr2O4 nanoparticles was confirmed by degradation of anionic dyes such as Eosin-Y and phenol red under UV light irradiation. The obtained ZnCr2O4 nanoparticles exhibit a paramagnetic behavior although bulk ZnCr2O4 is antiferromagnetic, this change in magnetic property can be ascribed to finite size effects.

  19. A novel Characterization Method for electric Properties of single Silver-coated Polymer Spheres

    OpenAIRE

    Stokkeland, August Emil Tobiesen

    2015-01-01

    The electrical properties of isotropic conductive adhesives (ICAs) are dependent on the filler concentration and electrical properties of the conductive additives. ICAs with metal-coated polymer spheres (MPS) are an efficient way of reducing the amount of precious metals in the adhesive without compromising the condcuting properties. Today little is known about the electrical properties of a single MPS and how the thickness of the metal coating relates to the electrical properties, because no...

  20. Structure-Property Characterization of the Crinkle-Leaf Peach Wood Phenotype: A Future Model System for Wood Properties Research?

    Science.gov (United States)

    Wiedenhoeft, Alex C.; Arévalo, Rafael; Ledbetter, Craig; Jakes, Joseph E.

    2016-08-01

    Nearly 400 million years of evolution and field-testing by the natural world has given humans thousands of wood types, each with unique structure-property relationships to study, exploit, and ideally, to manipulate, but the slow growth of trees makes them a recalcitrant experimental system. Variations in wood features of two genotypes of peach (Prunus persica L.) trees, wild-type and crinkle-leaf, were examined to elucidate the nature of weak wood in crinkle-leaf trees. Crinkle-leaf is a naturally-occurring mutation in which wood strength is altered in conjunction with an easily observed `crinkling' of the leaves' surface. Trees from three vigor classes (low growth rate, average growth rate, and high growth rate) of each genotype were sampled. No meaningful tendency of dissimilarities among the different vigor classes was found, nor any pattern in features in a genotype-by-vigor analysis. Wild-type trees exhibited longer vessels and fibers, wider rays, and slightly higher specific gravity. Neither cell wall mechanical properties measured with nanoindentation nor cell wall histochemical properties were statistically or observably different between crinkle-leaf and wild-type wood. The crinkle-leaf mutant has the potential to be a useful model system for wood properties investigation and manipulation if it can serve as a field-observable vegetative marker for altered wood properties.

  1. Structural characterization and optical properties of perovskite ZnZrO 3 nanoparticles

    KAUST Repository

    Zhu, Xinhua

    2014-03-17

    Perovskite ZnZrO3 nanoparticles were synthesized by hydrothermal method, and their microstructures and optical properties were characterized. The crystallinity, phase formation, morphology and composition of the as-synthesized nanoparticles were characterized by X-ray diffraction (XRD), selected area electron diffraction (SAED), high-resolutiontransmission electron microscopy (HRTEM), and energy-dispersive X-ray (EDX) spectroscopy analysis, respectively. TEM images demonstrated that the average particle size of the ZnZrO3 powders was increased with increasing the Zn/Zr molar ratios in the precursors, and more large ZnZrO3 particles with cubic morphology were observed at high Zn/Zr molar ratios. In addition, the phase structures of the ZnZrO3 particles were also evolved from a cubic to tetragonal perovskite phase, as revealed by XRD and SAED patterns. HRTEM images demonstrate that surface structures of the ZnZrO3 powders synthesized at high Zn/Zr molar ratios, are composed of corners bound by the {100} mini-facets, and the surface steps lying on the {100} planes are frequently observed, whereas the (101) facet isoccasionally observed. The formation of such a rough surface structure is understood from the periodic bond chain theory. Quantitative EDX analyses demonstrated that the atomic concentrations (at.%) of Zn:Zr:O in the particles were 20.70:21.07:58.23, as close to the composition of ZnZrO3. In the optical spectra, a significant red shift of the absorption edges (for the ZnZrO3 nanopowders) from UV to visible region (from 394 to 417 nm) was observed as increasing the Zn/Zr molar ratios in the precursors, which corresponds to that the band gap energies of the ZnZrO3 nanopowders can be continuously tuned from 3.15 to 2.97 eV. This opens an easy way to tune the band gap energies of the ZnZrO3 nanopowders. © 2014 The American Ceramic Society.

  2. Characterization of engineered alumina nanofibers and their colloidal properties in water

    International Nuclear Information System (INIS)

    Aluminum oxide nanofibers having different fiber diameters were characterized to determine if and how the fiber diameter affects their colloidal behavior and solubility in water. The measurements provide initial data on the behavior of alumina nanofibers in aqueous systems. Three different aluminum oxide materials with average fiber diameters ranging from a few nanometers to a few hundred nanometers were acquired from ANF Technology (Nafen™), MemPro Materials, and Pardam Nanotechnology. The morphology, dimensions, chemical composition, and surface properties of each material were measured using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, thermogravimetric analysis, and N2-BET surface area analysis. Properties measured for aqueous suspensions of the fibers included electrophoretic mobility, point of zero charge, apparent hydrodynamic radius via dynamic light scattering, and solubility. TEM images were used to determine the size distribution of the fiber diameter, and the smooth, non-porous, non-tubular structure of the materials. Fiber diameters were 5–10 nm for Nafen™, 90–175 nm for MemPro, and 150–600 nm for Pardam. SEM showed that samples of the dry materials consisted of long (micron sized) fibers having these diameters. Specific surface area ranged from 2.7 m2/g for the largest diameter Pardam fibers to 136 m2/g for the smallest diameter Nafen™ fibers. The pH of the point of zero charge for the three materials ranged from 5.0 for Pardam to 8.5 for Nafen™ in 10 mM NaCl. Dynamic light scattering revealed that the fibers readily aggregate in both deionized water and solutions of high ionic strength. Fiber solubility ranged from a dissolved aluminum concentration of 23–83 μg/L for pH from 6.67 to 8.23. The observed solubilities were similar to those calculated from thermodynamic data for corundum (α-Al2O3) and boehmite (γ-AlO(OH)), phases that were observed by XRD in the aged materials

  3. Characterizing the physical properties of solidified PEG, an analog for basaltic lava crust

    Science.gov (United States)

    Soule, S. A.; Cashman, K.; Rust, A.

    2001-12-01

    The crust of a basaltic lava flow provides significant resistance to flow and is an important indicator of lava flow dynamics. Analog studies using polyethylene glycol (PEG), such as those by Fink and Griffiths (1990) and Griffiths and Fink (1992), are a useful means to determine the conditions under which different crustal morphologies are produced. To accurately apply the results of these studies to natural systems, we must understand how to scale between basaltic lava and its analog, PEG. The long-term goal of our study is to characterize the physical properties of both materials for the purpose of developing scaling relationships. We have designed a set of experiments to determine the strength and viscosity of solidified PEG. We measure the ductile deformation and failure of PEG under tension and in simple shear. Experiments are conducted with either constant stress or constant strain rate and at a range of temperatures (5 to 25 \\deg C). Tension experiments are conducted on hourglass-shaped PEG casts with failure occurring at the midpoint of the hourglass. Tension is produced by hanging weight (constant stress) or by pulling with a DC servo motor (constant strain rate). Simple shear experiments are conducted by turning a gear frozen into a sheet of PEG. A thinned ring of crust centered around the gear controls the failure location. From constant stress experiments, we measure pre-failure ductile deformation of the PEG to determine its viscosity. Constant strain rate experiments allow us to determine the dependence of PEG strength on strain rate. To determine the physical properties of basaltic crust we are building a furnace capable of melting large quantities of basalt and conducting experiments at high temperature. The experiments conducted on PEG will aid in the design of similar experiments on lava. The results of this study will have applications beyond scaling between analog models and natural systems. The presence or absence of a continuous flow crust

  4. Characterization of engineered alumina nanofibers and their colloidal properties in water

    Energy Technology Data Exchange (ETDEWEB)

    Saunders, Zenille; Noack, Clinton W.; Dzombak, David A.; Lowry, Gregory V., E-mail: glowry@cmu.edu [Carnegie Mellon University, Civil & Environmental Engineering (United States)

    2015-03-15

    Aluminum oxide nanofibers having different fiber diameters were characterized to determine if and how the fiber diameter affects their colloidal behavior and solubility in water. The measurements provide initial data on the behavior of alumina nanofibers in aqueous systems. Three different aluminum oxide materials with average fiber diameters ranging from a few nanometers to a few hundred nanometers were acquired from ANF Technology (Nafen™), MemPro Materials, and Pardam Nanotechnology. The morphology, dimensions, chemical composition, and surface properties of each material were measured using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, thermogravimetric analysis, and N{sub 2}-BET surface area analysis. Properties measured for aqueous suspensions of the fibers included electrophoretic mobility, point of zero charge, apparent hydrodynamic radius via dynamic light scattering, and solubility. TEM images were used to determine the size distribution of the fiber diameter, and the smooth, non-porous, non-tubular structure of the materials. Fiber diameters were 5–10 nm for Nafen™, 90–175 nm for MemPro, and 150–600 nm for Pardam. SEM showed that samples of the dry materials consisted of long (micron sized) fibers having these diameters. Specific surface area ranged from 2.7 m{sup 2}/g for the largest diameter Pardam fibers to 136 m{sup 2}/g for the smallest diameter Nafen™ fibers. The pH of the point of zero charge for the three materials ranged from 5.0 for Pardam to 8.5 for Nafen™ in 10 mM NaCl. Dynamic light scattering revealed that the fibers readily aggregate in both deionized water and solutions of high ionic strength. Fiber solubility ranged from a dissolved aluminum concentration of 23–83 μg/L for pH from 6.67 to 8.23. The observed solubilities were similar to those calculated from thermodynamic data for corundum (α-Al{sub 2}O{sub 3}) and boehmite (γ-AlO(OH)), phases that were observed by XRD in the

  5. Design, synthesis, and characterization of new phosphazene related materials, and study the structure property correlations

    Science.gov (United States)

    Tian, Zhicheng

    The work described in this thesis is divided into three major parts, and all of which involve the exploration of the chemistry of polyphosphazenes. The first part (chapters 2 and 3) of my research is synthesis and study polyphoshazenes for biomedical applications, including polymer drug conjugates and injectable hydrogels for drug or biomolecule delivery. The second part (chapters 4 and 5) focuses on the synthesis of several organic/inorganic hybrid polymeric structures, such as diblock, star, brush and palm tree copolymers using living cationic polymerization and atom transfer radical polymerization techniques. The last part (chapters 6 and 7) is about exploratory synthesis of new polymeric structures with fluorinated side groups or cycloaliphatic side groups, and the study of new structure property relationships. Chapter 1 is an outline of the fundamental concepts for polymeric materials, as such the history, important definitions, and some introductory material for to polymer chemistry and physics. The chemistry and applications of phopshazenes is also briefly described. Chapter 2 is a description of the design, synthesis, and characterization of development of a new class of polymer drug conjugate materials based on biodegradable polyphosphazenes and antibiotics. Poly(dichlorophosphazene), synthesized by a thermal ring opening polymerization, was reacted with up to 25 mol% of ciprofloxacin or norfloxacin and three different amino acid esters (glycine, alanine, or phenylalanine) as cosubstituents via macromolecular substitutions. Nano/microfibers of several selected polymers were prepared by an electrospinning technique. Chapter 3 is concerned with the development of a class of injectable and biodegradable hydrogels based on water-soluble poly(organophosphazenes) containing oligo(ethylene glycol) methyl ethers and glycine ethyl esters. The hydrogels can be obtained by mixing alpha-cyclodextrin aqueous solution and poly(organophosphazenes) aqueous solution in

  6. Characterizations and Catalytic Properties of Transition Metal Ions Incorporated in Mesoporous Materials

    Institute of Scientific and Technical Information of China (English)

    WANG Ye

    2004-01-01

    Mesoporous materials typified by MCM-41 possess well-ordered mesoporous channels with controllable pore sizes from 2-30 nm, and are expected as desirable materials for catalysis.However, silicious mesoporous materials generally do not have sufficient intrinsic catalytic activities.Thus many studies have focused on introducing catalytically active sites. It is expected that different synthetic methods would result in different coordination structures of metal cations introduced in MCM-41, and thus different catalytic properties in catalytic reactions. The author's group has used two methods, i.e., direct hydrothermal synthesis (DHT) and template-ion exchange (TIE), for the syntheses of V-, Fe-, and Cr-MCM-41 and applied them as catalysts to selective oxidations of hydrocarbons. This paper highlights the characterizations of the coordination structures of these metal cations introduced into MCM-41 by the DHT and the TIE methods, and the structural-property relationships of these metal ion-containing MCM-41 materials in selective oxidation reactions.MCM-41 was prepared by hydrothermal synthesis using hexadecyltrimethylammonium bromide and sodium silicate as the sources of template and silicon, respectively. In the DHT method, metal cations were directly added into the synthesis gel before hydrothermal synthesis, while the exchanging of metal ions in ethanolic solutions with the template cations contained in the uncalcined MCM-41 was performed in the TIE method. XRD and N2-adsorption measurements showed that the mesoporous regularity was not destroyed with both synthetic methods for all the metal ion-containing MCM-41 with appropriate contents of metal cations.For V-MCM-41, the characterizations with mainly EXAFS suggested that V5+ cations were in tetrahedral coordination and mainly incorporated inside the framework of MCM-41 to substitute Si4+in the samples by the DHT method. Tetrahedrally coordinated Vanadyl species were also obtained by the TIE method, but the VO4

  7. Cr-Doped ZnO Nanoparticles: Synthesis, Characterization, Adsorption Property, and Recyclability.

    Science.gov (United States)

    Meng, Alan; Xing, Jing; Li, Zhenjiang; Li, Qingdang

    2015-12-16

    In this paper, a mild solvothermal method has been employed to successfully synthesize a series of Cr-doped ZnO nanoparticles (NPs) with different Cr(3+) contents, which is a kind of novel and high-efficiency absorbent for the removal of acid dye methyl orange (MO) from aqueous solution. The as-prepared products were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), Brunauer, Emmet, and Teller (BET), and Zeta potential measurements. In accordance with the adsorption capacity of the products, the obtained optimal Cr/Zn molar ratio is 6%. The adsorption process of MO on Cr-doped ZnO was investigated by kinetics, thermodynamics, and isotherm technologies, which, respectively, indicated that the adsorption was fast (adsorption reached equilibrium in 2 h) and followed a pseudo-second-order model, that the adsorption process was spontaneous and endothermic, and that it agreed well with the Langmuir isotherm with a maximum adsorption capacity of 310.56 mg g(-1). Moreover, a reasonable mechanism was proposed to elucidate the reasons for their adsorption behavior. In addition, a simple and low-cost chemical method was developed to separate and recycle ZnO and MO from the used adsorbent, effectively avoiding the secondary pollution. This work can not only describe efficient experimental approaches for obtaining novel adsorbents and recycling them but also offer valuable clues for the preparation and property study of other semiconductor adsorbents. PMID:26600320

  8. Synthesis, characterization and multifunctional properties of plasmonic Ag-TiO2 nanocomposites.

    Science.gov (United States)

    Prakash, Jai; Kumar, Promod; Harris, R A; Swart, Chantel; Neethling, J H; van Vuuren, A Janse; Swart, H C

    2016-09-01

    We report on the synthesis of multifunctional Ag-TiO2 nanocomposites and their optical, physio-chemical, surface enhanced Raman scattering (SERS) and antibacterial properties. A series of Ag-TiO2 nanocomposites were synthesized by sol-gel technique and characterized by x-ray diffraction, scanning and transmission electron microscopy, energy-dispersed x-ray analysis, photoluminescence, UV-vis, x-ray photoelectron and Raman spectroscopy and Brunauer-Emmett-Teller method. The Ag nanoparticles (NPs) (7-20 nm) were found to be uniformly distributed around and strongly attached to TiO2 NPs. The novel optical responses of the nanocomposites are due to the strong electric field from the localized surface plasmon (LSP) excitation of the Ag NPs and decreased recombination of photo-induced electrons and holes at Ag-TiO2 interface providing potential materials for photocatalysis. The nanocomposites show enhancement in the SERS signals of methyl orange (MO) molecules with increasing Ag content attributed to the long-range electromagnetic enhancement from the excited LSP of the Ag NPs. To further understand the SERS activity, molecular mechanics and molecular dynamics simulations were used to study the geometries and SERS enhancement of MO adsorbed onto Ag-TiO2 respectively. Simulation results indicate that number of ligands (MO) that adsorb onto the Ag NPs as well as binding energy per ligand increases with increasing NP density and molecule-to-surface orientation is mainly flat resulting in strong bond strength between MO and Ag NP surface and enhanced SERS signals. The antimicrobial activity of the Ag-TiO2 nanocomposites was tested against the bacterium Staphylococcus aureus and enhanced antibacterial effect was observed with increasing Ag content explained by contact killing action mechanism. These results foresee promising applications of the plasmonic metal-semiconductor based nano-biocomposites for both chemical and biological samples. PMID:27456278

  9. Functional properties and structural characterization of rice δ1-pyrroline-5-carboxylate reductase

    Science.gov (United States)

    Forlani, Giuseppe; Bertazzini, Michele; Zarattini, Marco; Funck, Dietmar; Ruszkowski, Milosz; Nocek, Bogusław

    2015-01-01

    The majority of plant species accumulate high intracellular levels of proline to cope with hyperosmotic stress conditions. Proline synthesis from glutamate is tightly regulated at both the transcriptional and the translational levels, yet little is known about the mechanisms for post-translational regulation of the enzymatic activities involved. The gene coding in rice (Oryza sativa L.) for δ1-pyrroline-5-carboxylate (P5C) reductase, the enzyme that catalyzes the second and final step in this pathway, was isolated and expressed in Escherichia coli. The structural and functional properties of the affinity-purified protein were characterized. As for most species, rice P5C reductase was able to use in vitro either NADH or NADPH as the electron donor. However, strikingly different effects of cations and anions were found depending on the pyridine nucleotide used, namely inhibition of NADH-dependent activity and stimulation of NADPH-dependent activity. Moreover, physiological concentrations of proline and NADP+ were strongly inhibitory for the NADH-dependent reaction, whereas the NADPH-dependent activity was mildly affected. Our results suggest that only NADPH may be used in vivo and that stress-dependent variations in ion homeostasis and NADPH/NADP+ ratio could modulate enzyme activity, being functional in promoting proline accumulation and potentially also adjusting NADPH consumption during the defense against hyperosmotic stress. The apparent molecular weight of the native protein observed in size exclusion chromatography indicated a high oligomerization state. We also report the first crystal structure of a plant P5C reductase at 3.40-Å resolution, showing a decameric quaternary assembly. Based on the structure, it was possible to identify dynamic structural differences among rice, human, and bacterial enzymes. PMID:26284087

  10. Functional properties and structural characterization of rice δ(1)-pyrroline-5-carboxylate reductase.

    Science.gov (United States)

    Forlani, Giuseppe; Bertazzini, Michele; Zarattini, Marco; Funck, Dietmar; Ruszkowski, Milosz; Nocek, Bogusław

    2015-01-01

    The majority of plant species accumulate high intracellular levels of proline to cope with hyperosmotic stress conditions. Proline synthesis from glutamate is tightly regulated at both the transcriptional and the translational levels, yet little is known about the mechanisms for post-translational regulation of the enzymatic activities involved. The gene coding in rice (Oryza sativa L.) for δ(1)-pyrroline-5-carboxylate (P5C) reductase, the enzyme that catalyzes the second and final step in this pathway, was isolated and expressed in Escherichia coli. The structural and functional properties of the affinity-purified protein were characterized. As for most species, rice P5C reductase was able to use in vitro either NADH or NADPH as the electron donor. However, strikingly different effects of cations and anions were found depending on the pyridine nucleotide used, namely inhibition of NADH-dependent activity and stimulation of NADPH-dependent activity. Moreover, physiological concentrations of proline and NADP(+) were strongly inhibitory for the NADH-dependent reaction, whereas the NADPH-dependent activity was mildly affected. Our results suggest that only NADPH may be used in vivo and that stress-dependent variations in ion homeostasis and NADPH/NADP(+) ratio could modulate enzyme activity, being functional in promoting proline accumulation and potentially also adjusting NADPH consumption during the defense against hyperosmotic stress. The apparent molecular weight of the native protein observed in size exclusion chromatography indicated a high oligomerization state. We also report the first crystal structure of a plant P5C reductase at 3.40-Å resolution, showing a decameric quaternary assembly. Based on the structure, it was possible to identify dynamic structural differences among rice, human, and bacterial enzymes. PMID:26284087

  11. Synthesis, structural characterization and photoluminescence properties of a novel La(III) complex

    Science.gov (United States)

    Köse, Muhammet; Ceyhan, Gökhan; Atcı, Emine; McKee, Vickie; Tümer, Mehmet

    2015-05-01

    In this study, a novel La(III) complex [La(H2L)2(NO3)3(MeOH)] of a Schiff base ligand was synthesized and characterized by spectroscopic and analytical methods. Single crystals of the complex suitable for X-ray diffraction study were obtained by slow diffusion of diethyl ether into a MeOH solution of the complex which was found to crystallise as [La(H2L)2(NO3)3(MeOH)]ṡ2MeOHṡH2O. The structure was solved in monoclinic crystal system, P21/n space group with unit cell parameters a = 10.5641(11), b = 12.6661(16), c = 16.0022(17) Å, α = 67.364(2), β = 83.794(2)°, γ = 70.541(2)°, V = 1862.9(4) Å3 and Z = 2 with R final value of 0.526. In the complex, the La(III) ion is ten-coordinated by O atoms, five of which come from three nitrate ions, four from the two Schiff base ligands and one from MeOH oxygen atom. The Schiff base ligands in the structure are in a zwitter ion form with the phenolic H transferred to the imine N atom. Thermal properties of the La(III) complex were examined by thermogravimetric analysis and the complex was found to be thermally stable up to 310 °C. The Schiff base ligand and its La(II) complex were screened for their in vitro antimicrobial activity against Bacillus megaterium, Staphylococcus aureus, Bacillus subtilis, Micrococcus luteus (Gram positive bacteria), Klebsiella pneumonia, Escherichia coli, Enterobacter aerogenes, Pseudomonas aeruginosa (Gram negative bacteria), Candida albicans,Yarrowia lipolytica (fungus) and Saccharomyces cerevisiae (yeast). The complex shows more antimicrobial activity than the free ligand.

  12. Silver chromate and silver dichromate nanostructures: Sonochemical synthesis, characterization, and photocatalytic properties

    International Nuclear Information System (INIS)

    Graphical abstract: In this work, Ag2CrO4 and Ag2Cr2O7 nanostructures have been sonochemically prepared using silver salicylate. The effect of preparation parameters on the morphology of the products was investigated by SEM images. Highlights: ► Herein, Ag2CrO4 and Ag2Cr2O7 nanostructures have been sonochemically prepared. ► The effect of preparation parameters on the morphology of the products was investigated. ► The photocatalytic activity of the as-prepared Ag2CrO4 nanoparticles was tested. ► XPS spectra indicated the high purity of Ag2Cr2O7 nanostructures obtained. - Abstract: In this work, Ag2CrO4 and Ag2Cr2O7 nanostructures have been produced via a sonochemical method using silver salicylate as precursor. Besides silver salicylate, Na2CrO4 and (NH4)2Cr2O7 as starting reagents were applied. To investigate the effect of preparation parameters on the morphology and particle size of Ag2CrO4 and Ag2Cr2O7, sonication time, type of surfactant and its concentration were changed. The as-produced nanostructures were characterized by techniques like powder X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. The scanning electron micrographs showed that particle-like and rod-like nanostructures of Ag2CrO4 and Ag2Cr2O7 were produced using different surfactants. To investigate the catalytic properties of Ag2CrO4 nanoparticles, photooxidation of methyl orange (MO) was performed. According to the obtained results, it was found that the methyl orange degradation was about 87.3% after 280 min irradiation of visible light

  13. Isolation, characterization and formulation properties of a new plant gum obtained from Cissus refescence

    Directory of Open Access Journals (Sweden)

    Emeje Martins

    2009-01-01

    Full Text Available This study elucidated the physical, thermal, sorption and functional properties of a gum obtained from the stem of Cissus refescence (CRG. Scanning electron microscopy (SEM, Particle size analysis, X-ray powder diffraction (XPRD, Thermo gravimetric analysis (TGA, Differential scanning colorimetry (DSC, Fourier transmittance infra red (FTIR, and Elemental analysis were used to characterize the gum sample. Tablets were prepared by incorporating an anti asthmatic drug; theophylline. In vitro drug release was carried out in simulated gastric and intestinal conditions. Effect of gum concentration on release kinetics was evaluated. CRG had a glass transition (Tg and melting peak of 233.5 and 270 o C respectively. This material showed a 10.59 % loss in weight at 195 o C. The sample had very strong peaks at approximately 14 o , 15 o , 23 o , 24 o , and 29 o 2θ degrees of 2-theta (θ in the X-Ray Powder Diffraction pattern. Elemental analysis showed that CRG contains 44.1, 7.1, 48.5, and 0.3% Carbon, Hydrogen, Oxygen and Nitrogen respectively. Release of theophylline under simulated biologic conditions varied between 2 to 12 hours depending on the concentration of the gum used in formulation. Drug release was found to be erosion-controlled initially (i.e. in SGF, but at later stage, it became swelling -controlled (i.e. in SIF. The results obtained in this study establish the fundamental characteristics of CRG. The matrices were pH sensitive and can potentially be used for intestinal drug delivery.

  14. Rapid characterization of the biomechanical properties of drug-treated cells in a microfluidic device

    International Nuclear Information System (INIS)

    Cell mechanics is closely related to many cell functions. Recent studies have suggested that the deformability of cells can be an effective biomarker to indicate the onset and progression of diseases. In this paper, a microfluidic chip is designed for rapid characterization of the mechanics of drug-treated cells through stretching with dielectrophoresis (DEP) force. This chip was fabricated using PDMS and micro-electrodes were integrated and patterned on the ITO layer of the chip. Leukemia NB4 cells were considered and the effect of all-trans retinoic acid (ATRA) drug on NB4 cells were examined via the microfluidic chip. To induce a DEP force onto the cell, a relatively weak ac voltage was utilized to immobilize a cell at one side of the electrodes. The applied voltage was then increased to 3.5 V pp and the cell started to be stretched along the applied electric field lines. The elongation of the cell was observed using an optical microscope and the results showed that both types of cells were deformed by the induced DEP force. The strain of the NB4 cell without the drug treatment was recorded to be about 0.08 (time t = 180 s) and the drug-treated NB4 cell was about 0.21 (time t = 180 s), indicating a decrease in the stiffness after drug treatment. The elastic modulus of the cell was also evaluated and the modulus changed from 140 Pa to 41 Pa after drug treatment. This microfluidic chip can provide a simple and rapid platform for measuring the change in the biomechanical properties of cells and can potentially be used as the tool to determine the biomechanical effects of different drug treatments for drug discovery and development applications. (paper)

  15. Synthesis, characterization and multifunctional properties of plasmonic Ag–TiO2 nanocomposites

    Science.gov (United States)

    Prakash, Jai; Kumar, Promod; Harris, R. A.; Swart, Chantel; Neethling, J. H.; Janse van Vuuren, A.; Swart, H. C.

    2016-09-01

    We report on the synthesis of multifunctional Ag–TiO2 nanocomposites and their optical, physio-chemical, surface enhanced Raman scattering (SERS) and antibacterial properties. A series of Ag–TiO2 nanocomposites were synthesized by sol–gel technique and characterized by x-ray diffraction, scanning and transmission electron microscopy, energy-dispersed x-ray analysis, photoluminescence, UV–vis, x-ray photoelectron and Raman spectroscopy and Brunauer–Emmett–Teller method. The Ag nanoparticles (NPs) (7–20 nm) were found to be uniformly distributed around and strongly attached to TiO2 NPs. The novel optical responses of the nanocomposites are due to the strong electric field from the localized surface plasmon (LSP) excitation of the Ag NPs and decreased recombination of photo-induced electrons and holes at Ag–TiO2 interface providing potential materials for photocatalysis. The nanocomposites show enhancement in the SERS signals of methyl orange (MO) molecules with increasing Ag content attributed to the long-range electromagnetic enhancement from the excited LSP of the Ag NPs. To further understand the SERS activity, molecular mechanics and molecular dynamics simulations were used to study the geometries and SERS enhancement of MO adsorbed onto Ag–TiO2 respectively. Simulation results indicate that number of ligands (MO) that adsorb onto the Ag NPs as well as binding energy per ligand increases with increasing NP density and molecule-to-surface orientation is mainly flat resulting in strong bond strength between MO and Ag NP surface and enhanced SERS signals. The antimicrobial activity of the Ag–TiO2 nanocomposites was tested against the bacterium Staphylococcus aureus and enhanced antibacterial effect was observed with increasing Ag content explained by contact killing action mechanism. These results foresee promising applications of the plasmonic metal‑semiconductor based nano-biocomposites for both chemical and biological samples.

  16. Synthesis, characterization and optical properties of sheet-like ZnO

    International Nuclear Information System (INIS)

    Highlights: → Sheet-like ZnO with regular hexagon shape was synthesized with a two-step method. → Sheet-like ZnO predecessor was synthesized at low temperature in open system. → The diameter and thickness of ZnO sheet can be controlled conveniently. → This low-cost and environmentally benign approach is controllable and reproducible. → Sheet-like ZnO may have potential application in optical and electrical devices. -- Abstract: Sheet-like ZnO with regular hexagon shape and uniform diameter has been successfully synthesized through a two-step method without any metal catalyst. First, the sheet-like ZnO precursor was synthesized in a weak alkaline carbamide environment with stirring in a constant temperature water-bath by the homogeneous precipitation method, then sheet-like ZnO was obtained by calcining at 600 oC for 2 h. The structures and optical properties of sheet-like ZnO have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), photoluminescence (PL) and UV-vis-NIR spectrophotometer. The results reveal that the product is highly crystalline with hexagonal wurtzite phase and has appearance of hexagon at (0 0 0 1) plane. The HRTEM images confirm that the individual sheet-like ZnO is single crystal. The PL spectrum exhibits a narrow ultraviolet emission at 397 nm and a broad visible emission centering at 502 nm. The band gap of sheet-like ZnO is about 3.15 eV.

  17. Biferroic LuCrO{sub 3}: Structural characterization, magnetic and dielectric properties

    Energy Technology Data Exchange (ETDEWEB)

    Durán, A., E-mail: dural@cnyn.unam.mx [Universidad Nacional Autónoma de México, Centro de Nanociencias y Nanotecnología, Km. 107 Carretera Tijuana-Ensenada, Apartado Postal 14, C.P. 22800 Ensenada, BC (Mexico); Meza F, C.; Morán, E.; Alario-Franco, M.A. [Departamento de Química Inorgánica y Laboratorio Complutense de Altas Presiones, Facultad de Química, Universidad Complutense de Madrid, EU, 28040 Madrid (Spain); Ostos, C., E-mail: ceostoso@gmail.com [Instituto de Química, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia)

    2014-02-14

    Multiferroic LuCrO{sub 3} perovskite-type structure (Pbnm) obtained via auto-ignition synthesis was characterized by a combination of X-ray diffraction (XRD) and thermogravimetric (TG) techniques, and through magnetization and permittivity measurements. Results showed that amorphous combustion powders were fully transformed to orthorhombic LuCrO{sub 3} structure at 1200 K after the first LuCrO{sub 4} crystallization at 700 K. The magnetic response displays thermal irreversibility between zero-field-cooling and field-cooling condition which is due to spin canted AF switching at 116 K. Accordingly, a hysteresis loop in the M(H) data confirms weak ferromagnetism in LuCrO{sub 3}. On the other hand, the permittivity measurement shows a broad peak transition typical of relaxor-type ferroelectrics transition at ∼450 K. Electrical conductivity increases as temperature increases showing an anomaly around the diffuse phase transition. The diffuse phase transition and the formation of the charge carriers are discussed in terms of a local distortion around the Lu Site. - Highlights: • Multiferroic LuCrO{sub 3} was successfully obtained via auto-ignition synthesis. • Amorphous powder is transformed first to LuCrO{sub 4} (700 K) and next to LuCrO{sub 3} (1100 K). • The CrO{sub 6} octahedra are tilted away and rotates from the ideal octahedral shape. • LuCrO{sub 3} exhibits a canted AFM transition (116 K) and a relaxor ferroelectric behavior. • Tilting and rotation of CrO{sub 6} octahedra influenced transport properties on LuCrO{sub 3}.

  18. Lidar-radar synergy for characterizing properties of ultragiant volcanic aerosol

    Science.gov (United States)

    Madonna, F.; Amodeo, A.; D'Amico, G.; Giunta, A.; Mona, L.; Pappalardo, G.

    2011-12-01

    , but from Central Europe where many lidar observations confirm the presence of volcanic aerosol in the previous days. Therefore, both CIAO lidar observations and the backtrajectory analysis suggests a volcanic origin of the ultragiant aerosol observed by the radar, revealing that these particles might have travelled for more than 4000 km after their injection into the atmosphere. The reported observation fostered a study, reported in this work, about the performances of multi-wavelength Raman lidars in the identification and the characterization of ultragiant aerosols layers in the troposphere. Results from simulations using Mie, T-Matrix and ray-tracing codes will be presented and compared with the observations performed in April-May 2010 during the Eyjafjallajökull eruption. Sensitivity ranges in detection of aerosol layer are pointed out in terms of experimental limits of both lidar and radar techniques and of aerosol optical depth. Moreover, recommendations for use of a combined lidar-radar approach for the aerosol typing and for the retrieval of their microphysical properties are reported.

  19. Characterization of Lactobacillus from Algerian goat's milk based on phenotypic, 16S rDNA sequencing and their technological properties

    Directory of Open Access Journals (Sweden)

    Ahmed Marroki

    2011-03-01

    Full Text Available Nineteen strains of Lactobacillus isolated from goat's milk from farms in north-west of Algeria were characterized. Isolates were identified by phenotypic, physiological and genotypic methods and some of their important technological properties were studied. Phenotypic characterization was carried out by studying physiological, morphological characteristics and carbohydrate fermentation patterns using API 50 CHL system. Isolates were also characterized by partial 16S rDNA sequencing. Results obtained with phenotypic methods were correlated with the genotypic characterization and 13 isolates were identified as L. plantarum, two isolates as L. rhamnosus and one isolate as L. fermentum. Three isolates identified as L. plantarum by phenotypic characterization were found to be L. pentosus by the genotypic method. A large diversity in technological properties (acid production in skim milk, exopolysaccharide production, aminopeptidase activity, antibacterial activity and antibiotic susceptibility was observed. Based on these results, two strains of L. plantarum (LbMS16 and LbMS21 and one strain of L. rhamnosus (LbMF25 have been tentatively selected for use as starter cultures in the manufacture of artisanal fermented dairy products in Algeria.

  20. Characterization of physical properties of Al2O3 and ZrO2 nanofluids for heat transfer applications

    International Nuclear Information System (INIS)

    Studies demonstrate that nanofluids based on metal oxide nanoparticles have physical properties that characterize them as promising fluids, mainly, in industrial systems in which high heat flux takes place. Water based nanofluids of Al2O3 and ZrO2 were characterized regarding its promising use in heat transfer applications. Three different concentrations of dispersed solutions of cited nanofluids were prepared (0.01% vol., 0.05% vol., and 0.1% vol.) from commercial nanofluids. Experimental measurements were carried out at different temperatures. Thermal conductivity, viscosity and density of the prepared nanofluids were measured. (author)

  1. Recommended Best Practices for the Characterization of Storage Properties of Hydrogen Storage Materials

    Energy Technology Data Exchange (ETDEWEB)

    None

    2010-03-01

    This is a reference guide to common methodologies and protocols for measuring critical performance properties of advanced hydrogen storage materials. It helps users to communicate clearly the relevant performance properties of new materials as they are discovered and tested.

  2. Structural characterizations and optical properties of new Li–Sr–Nb-phosphate glasses

    International Nuclear Information System (INIS)

    A new Li2O–SrO–Nb2O5–P2O5 glass system was prepared by a high-temperature alumina crucible, and structural characterization and optical properties were investigated. Proper content of Li2O and Nb2O5 was employed to replace partial SrO and P2O5 to improve the optical properties. It was observed that the enhancement of the refractive index from 1.75 to 1.85 is mainly due to the Nb2O5 content. An addition of Li2O significantly increases the optical transmittance; optical transparency can be enhanced from 60% to higher than 85% in the UV–visible region with addition of 20–40 mol% Li2O species. However, optical transmittance is monotonically decreased from about 90% to 80% under 10–30 mol% Nb2O5 addition. The 40P2O5–20Nb2O5–20SrO–20Li2O glasses demonstrate the optimum refractive index (n > 1.75) and high optical transparency (>80%) in the UV–visible region. Furthermore, the effect of Nb2O5 on the structural transition was focused on the (60 − y)P2O5–yNb2O5–20SrO–20Li2O vitreous system since the transition of FTIR spectra reveals that the Nb2O5 has more pronounced effect than Li2O in the glass network due to the higher covalent extent and electronegativity. Addition of Nb2O5 generates Nb–O bonds by dissociating P–O chains and results in the decrease in the intensity of the (PO2), (POP), and (PO3) absorption bands. The O1s-XPS analysis shows that Nb2O5 addition dissociates symmetric bridging oxygens in P–O–P bonding and forms asymmetric bridging oxygens in P–O–Nb and non-bridging Nb–O- bonds, in which octahedral [NbO6] unit is eventually substituted by [NbO4] tetrahedral unit in the Li–Sr–Nb phosphate glasses. - Highlights: • The prepared glasses demonstrate great optical properties (n = 1.65–1.85 and T > 80%). • The deconvoluted O1s XPS are presented to reveal oxygen bonding in the network. • Coloring effect in Sr–Nb phosphate glasses is eliminated by incorporation of Li2O. • The optical band gap is

  3. Characterization methods for silicon photodiode and silicon sub-surface properties

    OpenAIRE

    Haapalinna, Atte

    2004-01-01

    This thesis considers the characterization of silicon photodiode and the applications of silicon photodiodes in precision metrology, and some aspects of the silicon material characterizations. Such material characterizations are required in the process of semiconductor device manufacturing, one example of which is the silicon photodiode manufacturing. The motivation for the research on radiometry reported in this thesis has been the development of optical metrology at the Helsinki Univers...

  4. Characterization of the elastic properties of alloys used in the nuclear industry using non-destructive ultrasonic goniometry

    International Nuclear Information System (INIS)

    Ultrasonic goniometry is a powerful method for acoustic-elastic characterization of materials based on critical angle reflectivity measurements. Instrumental improvements and software refinements achieved over more than 10 years led the INR-Ultra-acoustic R and D Laboratory to the development of an automatic high resolution goniometer having an angular resolution of the order of 0.001o and a sensitivity of the phase velocity measurements (dV/V) of the order of 10-4. This apparatus is destined to systematic investigations of the acoustic-elastic properties of the metallic materials used in the nuclear industry. The paper presents experimental data concerning the characterization of elastic properties of zircaloy-4 thin wall tubes. (Author) 19 Refs

  5. Novel ion-exchange nanocomposite membrane containing in-situ formed FeOOH nanoparticles: Synthesis, characterization and transport properties

    Energy Technology Data Exchange (ETDEWEB)

    Heidary, Farhad; Kharat, Ali Nemati [University of Tehran, Tehran (Iran, Islamic Republic of); Khodabakhshi, Ali Reza [Faculty of Science, Arak University, Arak (Iran, Islamic Republic of)

    2016-04-15

    A new type of cation-exchange nanocomposite membrane was prepared via in-situ formation of FeOOH nanoparticles in a blend containing sulfonated poly (2,6-dimethyl-1,4-phenylene oxide) and sulfonated polyvinylchloride by a simple one-step chemical method. Prepared nanocomposite membranes were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray diffraction. The SEM images showed uniform dispersion of FeOOH nanoparticles throughout the polymeric matrices. The effect of additive loading on physicochemical and electrochemical properties of prepared cation-exchange nanocomposite membranes was studied. Various characterizations showed that the incorporation of different amounts of FeOOH nanoparticles into the basic membrane structure had a significant influence on the membrane performance and could improve the electrochemical properties.

  6. Synthesis and characterization of NiO nanoparticles by thermal decomposition of nickel linoleate and their optical properties

    Energy Technology Data Exchange (ETDEWEB)

    Kalam, Abul, E-mail: abul_k33@yahoo.com [Department of Chemistry, Faculty of Science, King Khalid University, Abha 61413, P.O. Box 9004 (Saudi Arabia); Al-Sehemi, Abdullah G.; Al-Shihri, Ayed S. [Department of Chemistry, Faculty of Science, King Khalid University, Abha 61413, P.O. Box 9004 (Saudi Arabia); Du Gaohui [Zhejiang Key Laboratory for Reactive Chemistry on Solid Surfaces, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004 (China); Ahmad, Tokeer [Nanochemistry Laboratory, Department of Chemistry, Jamia Millia Islamia, New Delhi 110025 (India)

    2012-06-15

    Well dispersed nickel oxide nanoparticles have been synthesized successfully by direct calcination of nickel linoleate. The structure, morphology and properties of the nanoparticles were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy and ultraviolet-visible spectroscopy. Transmission electron microscopic studies show that nickel oxide nanoparticles are uniform with an average size of 14-20 nm. The optical band gap of 3.8 eV is obtained using UV-Visible spectroscopy which exhibits the red shift compared with the bulk counterpart. - Highlights: Black-Right-Pointing-Pointer Synthesis of metal oxide nanoparticles by using metal complexes as precursors. Black-Right-Pointing-Pointer Characterization of isolated nanoparticles using XRD, FTIR, SEM, TEM and HRTEM data. Black-Right-Pointing-Pointer The expected optical properties of these nanoparticles are clarified.

  7. Solid-State Characterization and Dissolution Properties of Meloxicam–Moringa Coagulant–PVP Ternary Solid Dispersions

    OpenAIRE

    Noolkar, Suhail B.; Namdeo R Jadhav; Bhende, Santosh A.; Killedar, Suresh G.

    2013-01-01

    The effect of ternary solid dispersions of poor water-soluble NSAID meloxicam with moringa coagulant (obtained by salt extraction of moringa seeds) and polyvinylpyrrolidone on the in vitro dissolution properties has been investigated. Binary (meloxicam–moringa and meloxicam–polyvinylpyrrolidone (PVP)) and ternary (meloxicam–moringa–PVP) systems were prepared by physical kneading and ball milling and characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, a...

  8. Chemical characterization and bioactive properties of Prunus avium L.: The widely studied fruits and the unexplored stems

    OpenAIRE

    Bastos, Claudete; Barros, Lillian; Dueñas, Montserrat; Ricardo C. Calhelha; Queiroz, Maria João R. P.; Santos-Buelga, Celestino; Ferreira, Isabel C.F.R.

    2015-01-01

    The aim of this study was to characterize sweet cherry regarding nutritional composition of the fruits, and individual phytochemicals and bioactive properties of fruits and stems. The chromatographic profiles in sugars, organic acids, fatty acids, tocopherols and phenolic compounds were established. All the preparations (extracts, infusions and decoctions) obtained using stems revealed higher antioxidant potential than the fruits extract, which is certainly related with its hig...

  9. Antibacterial properties and chemical characterization of the essential oils from summer savory extracted by microwave-assisted hydrodistillation

    OpenAIRE

    Shila Rezvanpanah; Karamatollah Rezaei; Mohammad-Taghi Golmakani; Seyyed Hadi Razavi

    2011-01-01

    Antibacterial properties and chemical characterization of the essential oils from summer savory (Satureja hortensis) extracted by microwave-assisted hydrodistillation (MAHD) were compared with those of the essential oils extracted using the traditional hydrodistillation (HD) method. While MAHD at 660 W required half as much time as HD needed, similar antibacterial efficacies were found from the essential oils obtained by the two extraction methods on two food pathogens (Staphylococcus aureus,...

  10. MgO:Dy{sup 3+} nanophosphor: Self ignition route, characterization and its photoluminescence properties

    Energy Technology Data Exchange (ETDEWEB)

    Devaraja, P.B. [Prof. C.N.R. Rao Centre for Advanced Materials, Tumkur University, Tumkur 572 103 (India); Department of Physics, C.M.R.T.U, RV College of Engineering, Bangalore 560 059 (India); Department of Physics, Acharya Institute of graduate studies, Bangalore 560 090 (India); Avadhani, D.N. [Department of Physics, C.M.R.T.U, RV College of Engineering, Bangalore 560 059 (India); Nagabhushana, H., E-mail: bhushanvlc@gmail.com [Prof. C.N.R. Rao Centre for Advanced Materials, Tumkur University, Tumkur 572 103 (India); Prashantha, S.C., E-mail: scphysics@gmail.com [Research Center, Department of Science, East West Institute of Technology, Bangalore 560 091 (India); Sharma, S.C. [Chattisgarh Swamy Vivekananda Technological University, Bhilai, CG 493441 (India); Nagabhushana, B.M. [Department of Chemistry, M.S. Ramaiah Institute of Technology, Bangalore 560 054 (India); Nagaswarupa, H.P. [Research Center, Department of Science, East West Institute of Technology, Bangalore 560 091 (India); Daruka Prasad, B. [Department of Physics, B.M.S. Institute of Technology, Yelahanka, Bangalore 560 064 (India)

    2014-11-15

    For the first time series of MgO phosphors doped with different concentrations of Dy{sup 3+} (1–9 mol%) were prepared by solution combustion method using glycine as a fuel. The final products were well characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy. The powder X-ray diffraction patterns of the as-formed product show single cubic phase. The crystallite size estimated using Scherrer's method was found to be in the range 5–15 nm and the same was confirmed by transmission electron microscopy result. Photoluminescence properties of Dy{sup 3+} (1–9 mol%) doped MgO for near ultra violet excitation (325 nm) was studied in order to investigate the possibility of its use in white light emitting diode applications. The emission spectra consists of intra 4f transitions of Dy{sup 3+}, namely {sup 4}F{sub 9/2} → {sup 6}H{sub 15/2} (483 nm), and {sup 4}F{sub 9/2} → {sup 6}H{sub 13/2} (573 nm). Further, the emission at 573 nm shows strong yellow emission and can be applied to the yellow emission of phosphor for the application for near ultraviolet excitation. The intensity of yellow emission was attributed to intrinsic defects, especially oxygen-vacancies, which could assist the energy transfer from the MgO host to the Dy{sup 3+} ions. The Commission International De I-Eclairage chromaticity co-ordinates were calculated from emission spectra, the values (x,y) were very close to the National Television System Committee standard value of white emission. Therefore, the present phosphor was highly useful for display applications. - Graphical Abstract: PL emission spectra and CIE diagram of MgO:Dy{sup 3+} nanophosphor. - Highlights: • MgO:Dy{sup 3+} prepared by simple and low cost LCS method at low temperature (400 °C). • Characteristic emission peaks of Dy{sup 3+} ion at ∼ 483 and 573 nm are recorded. • CIE co-ordinate values located in the white region.

  11. Modification process optimization, characterization and adsorption property of granular fir-based activated carbon

    International Nuclear Information System (INIS)

    Highlights: • Granular fir-based activated carbon (GFAC) was modified with H2O2. • Orthogonal array design method was used to optimize the modification process. • Optimized parameters were: aqueous H2O2 concentration 1.0 mol l−1, modification temperature and time 30.0 °C and 4.0 h. • Adsorption capacity of the modified GFAC increased by 500.0% (caramel), 59.7% (methylene blue), 32.5% (phenol), and 15.1% (I2). • The pore structure parameters and surface oxygen groups changed in the modified GFAC. - Abstract: Granular fir-based activated carbon (GFAC) was modified with H2O2, and orthogonal array experimental design method was used to optimize the process. The properties of the original and modified GFAC were characterized by N2 adsorption–desorption isotherms, Brunauer–Emmett–Teller (BET) equation, Barett–Joyner–Halenda (BJH) equation, field emission scanning electron microscopy (FESEM), and Fourier transform infrared spectroscopy (FT-IR) analysis, etc. When 10.00 g of GFAC with particle size of 0.25–0.85 mm was modified by 150.0 ml of aqueous H2O2 solution, the optimized conditions were found to be as follows: aqueous H2O2 solution concentration 1.0 mol·l−1, modification temperature 30.0 °C, modification time 4.0 h. Modified under the optimized conditions, decolonization of caramel, methylene blue adsorption, phenol adsorption and iodine number of the modified GFAC increased by 500.0%, 59.7%, 32.5%, and 15.1%, respectively. The original and optimally modified GFAC exhibited adsorption isotherms of hybrid Type I–IV isotherms with H4 hysteresis. BET surface area, micropore area, total pore volume, micropore volume, and microporosity of the modified GFAC increased by 7.33%, 11.25%, 3.89%, 14.23%, 9.91%, respectively. Whereas the average pore width decreased by 3.16%. In addition, the amount of surface oxygen groups (such as carbonyl or carboxyl) increased in the modified GFAC

  12. Synthesis, characterization and sensing properties of ZnO-modified BN–FeB49

    International Nuclear Information System (INIS)

    Graphical abstract: ZnO-modified BN–FeB49 composite has been prepared though a facile route. The ZnO nanoparticles (8–10 nm) are embedded on the surface of the BN-coated nanorod successfully. The ZnO-modified BN–FeB49 composite has a higher sensitivity of 27.28% at 97 ppm and rapider response/recovery of less than 20 s to NOx at the room temperature. - Highlights: • The ZnO-modified BN–FeB49 composite has been prepared though a facile route. • The modified sample exhibits excellent gas-sensing properties to NOx. • The sample’s structure provides channels for capturing and migrating of electrons. - Abstract: A novel ZnO-modified BN–FeB49 composite has been synthesized by the reaction of BN–FeB49 nanorods and Zn(NO3)2 via a CVD process, and further characterized by XRD, IR and TEM. The results showed that the synthesized composite had more defects and sulfate radical, where the ZnO nanoparticles had been successfully embedded on the BN–FeB49 rods with the good dispersion size of 8–10 nm. It has been found that the unique structure of the composite provided more active sites for the adsorption of gaseous molecules. This was attributable to the chemical functionalization on the surface of the BN-coated nanorods and the increased surface-to-volume ratio of the samples. Compared with the bare BN-coated nanorods and the ZnO, our ZnO-modified BN–FeB49 composite showed preferential sensing activity of NOx at room temperature. It exhibited higher sensitivity of 27.28% at 97 ppm and rapider response/recovery of less than 20 s. Its structure provided effective and fast channels for fast capturing and migrating electrons. Thus ZnO-modified BN–FeB49 composite was expected to be applied for gas sensing

  13. MgO:Dy3+ nanophosphor: Self ignition route, characterization and its photoluminescence properties

    International Nuclear Information System (INIS)

    For the first time series of MgO phosphors doped with different concentrations of Dy3+ (1–9 mol%) were prepared by solution combustion method using glycine as a fuel. The final products were well characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy. The powder X-ray diffraction patterns of the as-formed product show single cubic phase. The crystallite size estimated using Scherrer's method was found to be in the range 5–15 nm and the same was confirmed by transmission electron microscopy result. Photoluminescence properties of Dy3+ (1–9 mol%) doped MgO for near ultra violet excitation (325 nm) was studied in order to investigate the possibility of its use in white light emitting diode applications. The emission spectra consists of intra 4f transitions of Dy3+, namely 4F9/2 → 6H15/2 (483 nm), and 4F9/2 → 6H13/2 (573 nm). Further, the emission at 573 nm shows strong yellow emission and can be applied to the yellow emission of phosphor for the application for near ultraviolet excitation. The intensity of yellow emission was attributed to intrinsic defects, especially oxygen-vacancies, which could assist the energy transfer from the MgO host to the Dy3+ ions. The Commission International De I-Eclairage chromaticity co-ordinates were calculated from emission spectra, the values (x,y) were very close to the National Television System Committee standard value of white emission. Therefore, the present phosphor was highly useful for display applications. - Graphical Abstract: PL emission spectra and CIE diagram of MgO:Dy3+ nanophosphor. - Highlights: • MgO:Dy3+ prepared by simple and low cost LCS method at low temperature (400 °C). • Characteristic emission peaks of Dy3+ ion at ∼ 483 and 573 nm are recorded. • CIE co-ordinate values located in the white region. • Present phosphor was quite useful for display applications

  14. Synthesis, characterization and luminescence properties of Eu3+-doped hydroxyapatite nanocrystal and the thermal treatment effects

    Science.gov (United States)

    Silva, Flávia R. O.; de Lima, Nelson B.; Bressiani, Ana Helena A.; Courrol, Lilia C.; Gomes, Laércio

    2015-09-01

    In this work, we present the synthesis, characterization and the luminescence properties of Ca10(PO4)6(OH)2 (hydroxyapatite/HAp) nanocrystals doped with europium trivalent ions. The most important processes that lead to europium emissions in the visible region were identified. Eu:HAp nanopowder excited at 394 nm (or 460 nm) exhibits several emissions: (i) weak emissions at 579 nm, 592 nm and 616 nm due to the 5D0 → 7F0, 5D0 → 7F1 and 5D0 → 7F2 transitions, respectively, with europium ion occupying site I in hydroxyapatite structure and (ii) strong emissions due to the 5D0 → 7F0 (574 nm), 5D0 → 7F1 (602 nm) and 5D0 → 7F2 (610-630 nm) transitions, when Eu3+ is occupying site II. The emission spectrum and the time-resolved luminescence analysis showed that the HAp nanocrystals (nanopowder) thermally treated at temperature (T) between 500 and 800 °C have a change in the initial Eu3+ site distribution of 100 % of Eu3+ at site I to a more stable one where the majority of europium ions are at site II: 30% remains at site I and 70% migrates to site II. In addition, an enhancement of the Eu3+ emission intensity is observed due to the increasing crystallite size. A time-resolved luminescence investigation using a short pulse laser excitation at 460 nm was employed to measure the luminescence decays and to determine the most important mechanisms involved in the deexcitation process of 5D0 excited state of Eu3+, where it is seen a fast (2.9 μs) energy transfer from Eu3+- site I (donor) to Eu3+- site II (acceptor) in the thermally treated nanopowders with T > 500 °C. The initial presence of 100% of Eu3+ at site I in the synthesized nanocrystals is gradually modified by the thermal treatments with temperatures above 500 °C by thermal activation of Ca2+ vacancy (the charge compensator) diffusion through the HAp lattice, which propitiates the Ca2+- vacancies and Eu3+ ions to exchange positions in the lattice. By this thermal activated mechanism, Eu3+ ion migrates

  15. Silver chromate and silver dichromate nanostructures: Sonochemical synthesis, characterization, and photocatalytic properties

    Energy Technology Data Exchange (ETDEWEB)

    Soofivand, Faezeh [Institute of Nano Science and Nano Technology, University of Kashan, Kashan, P.O. Box 87317-51167, Islamic Republic of Iran (Iran, Islamic Republic of); Mohandes, Fatemeh [Department of Inorganic Chemistry, Faculty of Chemistry, University of Kashan, Kashan, P.O. Box 87317-51167, Islamic Republic of Iran (Iran, Islamic Republic of); Salavati-Niasari, Masoud, E-mail: salavati@kashanu.ac.ir [Institute of Nano Science and Nano Technology, University of Kashan, Kashan, P.O. Box 87317-51167, Islamic Republic of Iran (Iran, Islamic Republic of); Department of Inorganic Chemistry, Faculty of Chemistry, University of Kashan, Kashan, P.O. Box 87317-51167, Islamic Republic of Iran (Iran, Islamic Republic of)

    2013-06-01

    Graphical abstract: In this work, Ag{sub 2}CrO{sub 4} and Ag{sub 2}Cr{sub 2}O{sub 7} nanostructures have been sonochemically prepared using silver salicylate. The effect of preparation parameters on the morphology of the products was investigated by SEM images. Highlights: ► Herein, Ag{sub 2}CrO{sub 4} and Ag{sub 2}Cr{sub 2}O{sub 7} nanostructures have been sonochemically prepared. ► The effect of preparation parameters on the morphology of the products was investigated. ► The photocatalytic activity of the as-prepared Ag{sub 2}CrO{sub 4} nanoparticles was tested. ► XPS spectra indicated the high purity of Ag{sub 2}Cr{sub 2}O{sub 7} nanostructures obtained. - Abstract: In this work, Ag{sub 2}CrO{sub 4} and Ag{sub 2}Cr{sub 2}O{sub 7} nanostructures have been produced via a sonochemical method using silver salicylate as precursor. Besides silver salicylate, Na{sub 2}CrO{sub 4} and (NH{sub 4}){sub 2}Cr{sub 2}O{sub 7} as starting reagents were applied. To investigate the effect of preparation parameters on the morphology and particle size of Ag{sub 2}CrO{sub 4} and Ag{sub 2}Cr{sub 2}O{sub 7}, sonication time, type of surfactant and its concentration were changed. The as-produced nanostructures were characterized by techniques like powder X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. The scanning electron micrographs showed that particle-like and rod-like nanostructures of Ag{sub 2}CrO{sub 4} and Ag{sub 2}Cr{sub 2}O{sub 7} were produced using different surfactants. To investigate the catalytic properties of Ag{sub 2}CrO{sub 4} nanoparticles, photooxidation of methyl orange (MO) was performed. According to the obtained results, it was found that the methyl orange degradation was about 87.3% after 280 min irradiation of visible light.

  16. Materials Characterization at Utah State University: Facilities and Knowledge-base of Electronic Properties of Materials Applicable to Spacecraft Charging

    Science.gov (United States)

    Dennison, J. R.; Thomson, C. D.; Kite, J.; Zavyalov, V.; Corbridge, Jodie

    2004-01-01

    In an effort to improve the reliability and versatility of spacecraft charging models designed to assist spacecraft designers in accommodating and mitigating the harmful effects of charging on spacecraft, the NASA Space Environments and Effects (SEE) Program has funded development of facilities at Utah State University for the measurement of the electronic properties of both conducting and insulating spacecraft materials. We present here an overview of our instrumentation and capabilities, which are particularly well suited to study electron emission as related to spacecraft charging. These measurements include electron-induced secondary and backscattered yields, spectra, and angular resolved measurements as a function of incident energy, species and angle, plus investigations of ion-induced electron yields, photoelectron yields, sample charging and dielectric breakdown. Extensive surface science characterization capabilities are also available to fully characterize the samples in situ. Our measurements for a wide array of conducting and insulating spacecraft materials have been incorporated into the SEE Charge Collector Knowledge-base as a Database of Electronic Properties of Materials Applicable to Spacecraft Charging. This Database provides an extensive compilation of electronic properties, together with parameterization of these properties in a format that can be easily used with existing spacecraft charging engineering tools and with next generation plasma, charging, and radiation models. Tabulated properties in the Database include: electron-induced secondary electron yield, backscattered yield and emitted electron spectra; He, Ar and Xe ion-induced electron yields and emitted electron spectra; photoyield and solar emittance spectra; and materials characterization including reflectivity, dielectric constant, resistivity, arcing, optical microscopy images, scanning electron micrographs, scanning tunneling microscopy images, and Auger electron spectra. Further

  17. Characterization of mechanical properties and microstructure of highly irradiated SS 316

    Science.gov (United States)

    Karthik, V.; Kumar, RanVijay; Vijayaragavan, A.; Venkiteswaran, C. N.; Anandaraj, V.; Parameswaran, P.; Saroja, S.; Muralidharan, N. G.; Joseph, Jojo; Kasiviswanathan, K. V.; Jayakumar, T.; Raj, Baldev

    2013-08-01

    Cold worked austenitic stainless steel type AISI 316 is used as the material for fuel cladding and wrapper of the Fast Breeder Test Reactor (FBTR), India. The evaluation of mechanical properties of these core structurals is very essential to assess its integrity and ensure safe and productive operation of FBTR to very high burn-ups. The changes in the mechanical properties of these core structurals are associated with microstructural changes caused by high fluence neutron irradiation and temperatures of 673-823 K. Remote tensile testing has been used for evaluating the tensile properties of irradiated clad tubes and shear punch test using small disk specimens for evaluating the properties of irradiated hexagonal wrapper. This paper will highlight the methods employed for evaluating the mechanical properties of the irradiated cladding and wrapper and discuss the trends in properties as a function of dpa (displacement per atom) and irradiation temperature.

  18. On the Characterization of Dredged Marine Soils from Malaysian Waters: Physical Properties

    OpenAIRE

    Zarina Shahri; Chee-Ming Chan

    2015-01-01

    Every year, large volumes of dredged marine soils (DMS) are removed from Malaysian water. Dredging activity is needed to maintain and enlarge water bodies. DMS properties are varies depending to space, time and land uses in the watershed. DMS were also reported to be contaminated with chemical and biological contaminants, making the materials risky for reuse. Information on DMS properties, e.g. physical, chemical and biological properties is essential to the selection of a suitable reuse opti...

  19. Template preparation of strontium hexaferrite (SrFe12O19) micro/nanostructures: Characterization, synthesis mechanism and magnetic properties

    International Nuclear Information System (INIS)

    Using electrospun thermoplastic ester elastomer (TPEE) micro/nanofibers as the template, strontium hexaferrite micro/nanostructures with different morphologies were prepared successfully by a combination process composed of sol-gel precursor coating technique and subsequent calcination. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM) were used to characterize the morphology, crystalloid structure and the magnetic properties of samples. The relation between the fabricated structure morphologies and TPEE micro/nanofibers properties was studied. It was believed that the hydrogen bond effect competition between TPEE/precursors and precursors/precursors played an important role on the formation of the obtained structures. In addition, the influence of annealing time and annealing rate on the magnetic properties of the samples obtained was investigated. The structures thus fabricated can be potential materials in many fields, drug delivery and photocatalysts for example.

  20. Synthesis, microstructural characterization and optical properties of CuO nanorods and nanowires obtained by aerosol assisted CVD

    Energy Technology Data Exchange (ETDEWEB)

    Lugo-Ruelas, M. [Centro de Investigación en Materiales Avanzados S.C., Laboratorio Nacional de Nanotecnología, Miguel de Cervantes No. 120, Chihuahua, Chih. C.P. 31109 (Mexico); Universidad Autónoma de Chihuahua, Facultad de Ingeniería, Circuito No. 1, Nuevo Campus Universitario, Apdo. Postal 1552, Chihuahua, Chih. C.P. 31240 (Mexico); Amézaga-Madrid, P. [Centro de Investigación en Materiales Avanzados S.C., Laboratorio Nacional de Nanotecnología, Miguel de Cervantes No. 120, Chihuahua, Chih. C.P. 31109 (Mexico); Esquivel-Pereyra, O. [Centro de Investigación en Materiales Avanzados S.C., Laboratorio Nacional de Nanotecnología, Miguel de Cervantes No. 120, Chihuahua, Chih. C.P. 31109 (Mexico); Universidad Autónoma de Chihuahua, Facultad de Ingeniería, Circuito No. 1, Nuevo Campus Universitario, Apdo. Postal 1552, Chihuahua, Chih. C.P. 31240 (Mexico); Antúnez-Flores, W.; Pizá-Ruiz, P.; Ornelas-Gutiérrez, C. [Centro de Investigación en Materiales Avanzados S.C., Laboratorio Nacional de Nanotecnología, Miguel de Cervantes No. 120, Chihuahua, Chih. C.P. 31109 (Mexico); Miki-Yoshida, M., E-mail: mario.miki@cimav.edu.mx [Centro de Investigación en Materiales Avanzados S.C., Laboratorio Nacional de Nanotecnología, Miguel de Cervantes No. 120, Chihuahua, Chih. C.P. 31109 (Mexico)

    2015-09-15

    Highlights: • Nanorods and nanowires of CuO were successfully synthesized by AACVD technique. • The carrier gas velocity was a determinant factor for the growth of nanorods or nanowires. • The increase of deposition time generates the reduction in the evenness and distribution density. • The crystalline phase of nanorods and nanowires was monoclinic tenorite. - Abstract: Copper oxide is a particularly interesting material because it presents photovoltaic, electrochemical and catalytic properties. Its unique properties are very important in the area of nanotechnology and may be an advantage because these nanomaterials can be applied in the design and manufacture of nanosensors, photocatalysis area, nanolasers switches and transistors. Nowadays one-dimensional nanostructures as nanorods, nanowires, etc., have generated a great importance and have received considerable attention and study due to their unique physical and chemical properties. In this work we report the synthesis, microstructural characterization and optical properties of CuO nanorods and nanowires grown by aerosol assisted chemical vapor deposition onto a CuO, ZnO and TiO{sub 2} thin film covered and bare borosilicate glass substrate. Concentration of the precursor solution and carrier gas flux were previously optimized and fixed at 0.1 mol dm{sup −3} and 5 L min{sup −1}, respectively. Other deposition parameters such as substrate temperature, as well the carrier gas velocity and deposition time were varied from 623 to 973 K, 0.88 to 1.77 m s{sup −1} and 11 to 16 min, respectively. Their influence on the morphology, microstructure and optical properties of the nanorods and nanowires were analyzed. The crystalline structure of the materials was characterized by grazing incidence X-ray diffraction; results indicate the presence of the tenorite phase. Surface morphology and microstructure were studied by field emission scanning electron microscopy, and high resolution transmission electron

  1. Synthesis, microstructural characterization and optical properties of CuO nanorods and nanowires obtained by aerosol assisted CVD

    International Nuclear Information System (INIS)

    Highlights: • Nanorods and nanowires of CuO were successfully synthesized by AACVD technique. • The carrier gas velocity was a determinant factor for the growth of nanorods or nanowires. • The increase of deposition time generates the reduction in the evenness and distribution density. • The crystalline phase of nanorods and nanowires was monoclinic tenorite. - Abstract: Copper oxide is a particularly interesting material because it presents photovoltaic, electrochemical and catalytic properties. Its unique properties are very important in the area of nanotechnology and may be an advantage because these nanomaterials can be applied in the design and manufacture of nanosensors, photocatalysis area, nanolasers switches and transistors. Nowadays one-dimensional nanostructures as nanorods, nanowires, etc., have generated a great importance and have received considerable attention and study due to their unique physical and chemical properties. In this work we report the synthesis, microstructural characterization and optical properties of CuO nanorods and nanowires grown by aerosol assisted chemical vapor deposition onto a CuO, ZnO and TiO2 thin film covered and bare borosilicate glass substrate. Concentration of the precursor solution and carrier gas flux were previously optimized and fixed at 0.1 mol dm−3 and 5 L min−1, respectively. Other deposition parameters such as substrate temperature, as well the carrier gas velocity and deposition time were varied from 623 to 973 K, 0.88 to 1.77 m s−1 and 11 to 16 min, respectively. Their influence on the morphology, microstructure and optical properties of the nanorods and nanowires were analyzed. The crystalline structure of the materials was characterized by grazing incidence X-ray diffraction; results indicate the presence of the tenorite phase. Surface morphology and microstructure were studied by field emission scanning electron microscopy, and high resolution transmission electron microscopy. Optical

  2. Operator Characterizations and Some Properties of g-Frames on Hilbert Spaces

    OpenAIRE

    Guo, Xunxiang

    2013-01-01

    Given the g-orthonormal basis for Hilbert space H, we characterize the g-frames, normalized tight g-frames, and g-Riesz bases in terms of the g-preframe operators. Then we consider the transformations of g-frames, normalized tight g-frames, and g-Riesz bases, which are induced by operators and characterize them in terms of the operators. Finally, we discuss the sums and g-dual frames of g-frames by applying the results of characterizations.

  3. Characterization of Oligomeric and Kinetic Properties of Tomato Thymidine Kinase 1

    DEFF Research Database (Denmark)

    Mutahir, Zeeshan; Larsen, Nicolai Balle; Andersson, Karl-Magnus;

    2011-01-01

    AZT can easily penetrate the blood–brain barrier and toTK1 can efficiently phosphorylate AZT and also AZT-monophosphate. In a pursuit to further understand the properties of toTK1, we examined the oligomerization properties of recombinant toTK1 and its effect on enzyme kinetics. Previously, it has...

  4. Characterization of Birefringence and Dispersion Properties in an Arrayed Waveguide Grating

    Institute of Scientific and Technical Information of China (English)

    Jeong Hwan Song; Oh Dal Kwon; Dong-Su Kim; Sun Tae Jung; Kyung Shik Lee

    2003-01-01

    We have characterized polarization dependent loss(PDL), differential group delay(DGD), and chromatic dispersion of an AWG and a simple method was proposed to estimate the chromatic dispersion from the measured DGD of the device.

  5. Thermal Properties of Materials Characterized by Scanning Electron-Acoustic Microscopy

    Institute of Scientific and Technical Information of China (English)

    GAO Chun-Ming; ZHANG Shu-Yi; ZHANG Zhong-Ning; SHUI Xiu-Ji; JIANG Tao

    2005-01-01

    @@ A modified technique of scanning electron-acoustic microscopy is employed to determine thermal diffusivity of materials. Using the dependence of the electron-acoustic signal on modulation frequency of the electron beam,the thermal diffusivity of materials is characterized based on a simplified thermoelastic theory. The thermal diffusivities of several metals characterized by the modified scanning electron-acoustic microscopy are in good agreement with the referential values of the corresponding materials, which proves that the scanning electronacoustic microscopy can be used to characterize the thermal diffusivity of materials effectively. In addition, for micro-inhomogeneous materials, such as biological tissues, the macro-effective (average) thermal diffusivities are characterized by the technique.

  6. Characterizing adsorptive properties and DOC concentrations in soils of Northern European Russian tundra and taiga.

    Science.gov (United States)

    Oosterwoud, Marieke; Temminghoff, Erwin; van der Zee, Sjoerd

    2010-05-01

    Subarctic river basins have an enormous potential to mobilize and transport terrestrial OC to the Arctic Ocean, because 23-48% of the worlds soils organic carbon (SOC) is stored in the high latitude region. Currently the Arctic drainage basin (~24 x 106 km2) processes about 11% of the global dissolved organic carbon (DOC), which is exported to the ocean. About 10-25% of annual C input to the organic surface layer with litter is leached from the organic surface layers. As climate changes, the amount and chemical composition of DOC exported from these basins are expected to change. Adsorption of DOC on mineral phases is the key geochemical process for the release and removal of DOC from this potentially soluble carbon pool. Most DOC leached from organic horizons is adsorbed and retained in the subsoils. The adsorption depends much on the content of sesquioxides and amount of carbon previously accumulated in soils. Besides adsorption, polyvalent metal ions in solution, such as Al and Ca, can cause precipitation of DOC. Along with the decrease of DOC concentrations on its passage through mineral soil, there are major biochemical alterations of DOC composition. Hydrophobic compounds (humic and fulvic acids) of high molecular weight that are rich in acidic functional groups and aromatic compounds adsorb most strongly. Hydrophilic compounds can contribute to DOC adsorption but are also easily desorbed because of the weaker bonding strength. The aim of this study was to characterize the DOC concentrations and their chemical composition as well as the DOC adsorptive properties of soils found in a tundra and taiga catchment of Northern Russia. We sampled soil and soil solution from two catchments in the Komi Republic of European Northern Russia: a tundra (67N/62E) and a taiga (62N/50E). The soil samples were analysed for total organic carbon (Ct) and the content of sequioxides. By extracting soil samples with water we got an impression of the potentially extractable organic

  7. An experimental comparison of laboratory techniques in determining bulk properties of tuffaceous rocks; Yucca Mountain Site Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, P.J.; Martin, R.J. III [New England Research, Inc., White River Junction, VT (United States); Price, R.H. [Sandia National Labs., Albuquerque, NM (United States). YMP Performance Assessment Applications Dept.

    1994-04-01

    Samples of tuffaceous rock were studied as part of the site characterization for a potential nuclear waste repository at Yucca Mountain in southern Nevada. These efforts were scoping in nature, and their results, along with those of other investigations, are being used to develop suitable procedures for determining bulk properties of tuffaceous rock in support of thermal and mechanical properties evaluations. Comparisons were made between various sample preparation, handling, and measurement techniques for both zeolitized and nonzeolitized tuff in order to assess their effects on bulk property determinations. Laboratory tests included extensive drying regimes to evaluate dehydration behavior, the acquisition of data derived from both gas and water pycnometers to compare their suitability in determining grain densities, a comparison of particle size effects, and a set of experiments to evaluate whole core saturation methods. The results affirm the added complexity of these types of measurements where there is a zeolite component in the sample mineralogy. Absolute values for the bulk properties of zeolitized tuff are immeasurable due to the complex nature of their dehydration behavior. However, the results of the techniques that were investigated provide a basis for the development of preferred, consistent methods for determining the grain density, dry and saturated bulk densities, and porosity of tuffaceous rock, including zeolitic tuff in support of thermal and mechanical properties evaluations.

  8. SELECTION AND MEASUREMENT OF PHYSICAL PROPERTIES FOR CHARACTERIZATION OF CHEMICAL PROTECTIVE CLOTHING MATERIALS

    Science.gov (United States)

    Chemical protective clothing (CPC) must possess certain physical properties if it is to function as an effective barrier to chemicals. he physical characteristics of CPC materials has gone largely unstudied; most attention has been focussecd on chemical resistance. hysical proper...

  9. Advanced methods for structural characterization and structure-property correlation for functional materials of layered compounds

    OpenAIRE

    Dürrschnabel, Michael Thomas

    2014-01-01

    A large number of functional materials have layered structures yielding anisotropic physical properties and an exciting physics of extended defects. For the understanding of both phenomena extensive computational methods are necessary for calculating anisotropic physical properties in an ab-initio approach. Calculating high-energy electron scattering is essential to yield quantitative results on defect structures by electron microscopy and spectroscopy. In this thesis superconducting ReBa2Cu3...

  10. Characterization and Mechanical Properties of WC-Co Based Scratch Tips

    OpenAIRE

    ERDOĞAN, Muzaffer; EROL, Ayhan; Yönetken, Ahmet

    2013-01-01

    Tungsten carbide is known to have excellent high hardness and wear resistance carbide ceramics feature. Thanks to its superior properties and wear resistance carbide cutting-plotter teams, if desired, the industry has a wide application area. In this study, the WC-based material, ceramic material Co. To produce composite samples. In other words, ceramic and metal powders, with powder metallurgy technique, of mechanical properties and composite materials to produce the survey covers. WC powder...

  11. Synthesis, characterization and properties of novel amide derivatives based open-chain crown ether and their Tb (III) complexes

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yanhong; He, Wei [School of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); Yang, Zehui [School of Chemical Engineering, Ningbo University of Technology, Ningbo 315016 (China); Chen, Yanwen [Hunan Labour Protection Institute of Nonferrous Metals, Changsha 410014 (China); Wang, Xinwei [School of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); Guo, Dongcai, E-mail: dcguo2001@hnu.edu.cn [School of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China)

    2015-04-15

    Six amide-based open-chain crown ether and their solid complexes with terbium nitrates were synthesized. The target complexes were characterized by elemental analysis, mass spectra, EDTA titrimetric analysis, thermal analysis, molar conductivity, infrared spectra and UV–vis spectra. Luminescence properties of the ligands and the corresponding complexes in solid were studied. The results showed that the introduction of electron-donating group to the ligand enhanced the luminescence intensity of the corresponding complex, but electron-withdrawing group conversely. Meanwhile, among all complexes, the luminescence quantum yield of the complex Tb(NO{sub 3}){sub 3}Y{sup 1} was highest up to 0.76. Electrochemical properties were also investigated, and the results showed that the introduction of electron-donating group to the ligand enhanced the highest occupied molecular orbit (HOMO) and the lowest unoccupied molecular orbit (LUMO) energy level, but electron-withdrawing group conversely. And these target complexes may possibly be useful for studying in organic light-emitting devices field. - Highlights: • Novel amide derivatives based open-chain crown ether and their Tb (III) complexes were prepared and characterized. • The target complexes presented high thermodynamic stability. • Influence of the substituent on luminescence intensity and electrochemical property were discussed.

  12. Synthesis, characterization and properties of novel amide derivatives based open-chain crown ether and their Tb (III) complexes

    International Nuclear Information System (INIS)

    Six amide-based open-chain crown ether and their solid complexes with terbium nitrates were synthesized. The target complexes were characterized by elemental analysis, mass spectra, EDTA titrimetric analysis, thermal analysis, molar conductivity, infrared spectra and UV–vis spectra. Luminescence properties of the ligands and the corresponding complexes in solid were studied. The results showed that the introduction of electron-donating group to the ligand enhanced the luminescence intensity of the corresponding complex, but electron-withdrawing group conversely. Meanwhile, among all complexes, the luminescence quantum yield of the complex Tb(NO3)3Y1 was highest up to 0.76. Electrochemical properties were also investigated, and the results showed that the introduction of electron-donating group to the ligand enhanced the highest occupied molecular orbit (HOMO) and the lowest unoccupied molecular orbit (LUMO) energy level, but electron-withdrawing group conversely. And these target complexes may possibly be useful for studying in organic light-emitting devices field. - Highlights: • Novel amide derivatives based open-chain crown ether and their Tb (III) complexes were prepared and characterized. • The target complexes presented high thermodynamic stability. • Influence of the substituent on luminescence intensity and electrochemical property were discussed

  13. Structural characterization, antioxidant and anticancer properties of gold nanoparticles synthesized from leaf extract(decoction)of Antigonon leptopus Hook. &Arn.

    Science.gov (United States)

    Balasubramani, Govindasamy; Ramkumar, Rajendiran; Krishnaveni, Narayanaswamy; Pazhanimuthu, Annamalai; Natarajan, Thillainathan; Sowmiya, Rajamani; Perumal, Pachiappan

    2015-04-01

    Tea is an aromatic beverage prepared by pouring boiling water over alleviated leaves of the tea plant. Tea prepared from the aerial parts of Antigonon leptopus has been traditionally used as remedy for cold, diabetes and pain in many countries. The gold nanoparticles (Au NPs) synthesized from powdered leaf extract (decoction) of A. leptopus were characterized by UV–visible spectroscopy (UV–vis), X-ray diffraction (XRD), Fourier transform-infrared (FT-IR), high resolution transmission electron microscopy (HR-TEM), selected area electron diffraction (SAED) pattern and energy dispersive X-ray (EDX) analyses to define the formation of Au NPs. Further, the synthesized Au NPs were well characterized based on their strong surface plasmon resonance (SPR), crystalline nature, functional groups, size and dispersed shapes, purity and Bragg's reflections of face centered cubic (fcc) structure of metallic gold. The Au NPs showed higher free radical scavenging property when compared to the effect of leaf extract. Cytotoxicity study of synthesized Au NPs exhibited the growth inhibitory property at the concentration (GI50) of 257.8 μg/mL in human adenocarcinoma breast cancer (MCF-7) cells after 48 h. Thus, the Au NPs synthesized from the Mexican creeper, A. leptopus revealed the important biological properties: as a free radical as well as anticancer agent. We conclude that the A. leptopus derived biological materials have promising potential as a source for the development of anticancer drug in future. PMID:25432487

  14. Characterization of temperature-dependent optical material properties of polymer powders

    International Nuclear Information System (INIS)

    In former works, the optical material properties of different polymer powders used for Laser Beam Melting (LBM) at room temperature have been analyzed. With a measurement setup using two integration spheres, it was shown that the optical material properties of polymer powders differ significantly due to multiple reflections within the powder compared to solid bodies of the same material. Additionally, the absorption behavior of the single particles shows an important influence on the overall optical material properties, especially the reflectance of the powder bed. Now the setup is modified to allow measurements at higher temperatures. Because crystalline areas of semi-crystalline thermoplastics are mainly responsible for the absorption of the laser radiation, the influence of the temperature increase on the overall optical material properties is analyzed. As material, conventional polyamide 12 and polypropylene as new polymer powder material, is used. By comparing results at room temperature and at higher temperatures towards the melting point, the temperature-dependent optical material properties and their influence on the beam-matter interaction during the process are discussed. It is shown that the phase transition during melting leads to significant changes of the optical material properties of the analyzed powders

  15. Simplified method to characterize municipal solid waste properties under seismic conditions.

    Science.gov (United States)

    Choudhury, Deepankar; Savoikar, Purnanand

    2009-02-01

    The response of municipal solid waste landfills during earthquakes is gaining worldwide attention due to the devastating nature of earthquakes on landfills. Safety code provisions and regulations of various countries require the incorporation of safety measures against seismic hazards in the design of new landfills, as well as for extensions of existing landfills in seismic zones. Determination of dynamic properties is the first step for the analysis of municipal solid waste materials under seismic conditions. Landfill composition and properties, like unit weight, shear wave velocity, shear strength, normalized shear modulus, and material damping, are the most important dynamic properties that have direct impact on the seismic behaviour of landfills, and need to be evaluated carefully. In the present study, based on the extensive data provided by various researchers, the dynamic properties of landfill materials are analyzed using curve-fitting techniques, and simple mathematical equations are proposed. The resulting profiles are compared with laboratory and field data wherever possible. These properties are difficult to generalize and may vary from landfill to landfill. Hence, the proposed simple mathematical models for these landfill properties can be used to design municipal solid waste landfills in the absence of landfill-specific field data under seismic conditions. PMID:18682319

  16. Simplified method to characterize municipal solid waste properties under seismic conditions

    International Nuclear Information System (INIS)

    The response of municipal solid waste landfills during earthquakes is gaining worldwide attention due to the devastating nature of earthquakes on landfills. Safety code provisions and regulations of various countries require the incorporation of safety measures against seismic hazards in the design of new landfills, as well as for extensions of existing landfills in seismic zones. Determination of dynamic properties is the first step for the analysis of municipal solid waste materials under seismic conditions. Landfill composition and properties, like unit weight, shear wave velocity, shear strength, normalized shear modulus, and material damping, are the most important dynamic properties that have direct impact on the seismic behaviour of landfills, and need to be evaluated carefully. In the present study, based on the extensive data provided by various researchers, the dynamic properties of landfill materials are analyzed using curve-fitting techniques, and simple mathematical equations are proposed. The resulting profiles are compared with laboratory and field data wherever possible. These properties are difficult to generalize and may vary from landfill to landfill. Hence, the proposed simple mathematical models for these landfill properties can be used to design municipal solid waste landfills in the absence of landfill-specific field data under seismic conditions

  17. Improved characterization of cartilage mechanical properties using a combination of stress relaxation and creep.

    Science.gov (United States)

    Chin, Hooi Chuan; Khayat, Ghazaleh; Quinn, Thomas M

    2011-01-01

    Mechanical characterization of cartilage, other soft tissues and gels has become a ubiquitous and essential aspect of biomechanics and biomaterials research. Current progress in theoretical modeling and tools for data analysis often exceed what is required for routine mechanical characterization assays in experimental studies, making selection of methodologies difficult for the nonspecialist. We have therefore developed an approach for measurement of confined compression modulus and hydraulic permeability based on simple poroelasticity theory and requiring only linear regression tools for data analysis. This technique involves a new application of an early-time solution for creep combined with stress relaxation measurements to characterize soft tissue mechanical parameters as a function of compressive strain or water content. This combined methodology allows measurement of hydraulic permeability by two different techniques with only a modest increase in experimental duration, providing a more precise assessment of permeability and associated measurement error. PMID:20869717

  18. Characterization of scale-free properties of human electrocorticography in awake and slow wave sleep states

    Directory of Open Access Journals (Sweden)

    John M Zempel

    2012-06-01

    Full Text Available Like many complex dynamic systems, the brain exhibits scale-free dynamics that follow power law scaling. Broadband power spectral density (PSD of brain electrical activity exhibits state-dependent power law scaling with a log frequency exponent that varies across frequency ranges. Widely divergent naturally occurring neural states, awake and slow wave sleep (SWS periods, were used evaluate the nature of changes in scale-free indices. We demonstrate two analytic approaches to characterizing electrocorticographic (ECoG data obtained during Awake and SWS states. A data driven approach was used, characterizing all available frequency ranges. Using an Equal Error State Discriminator (EESD, a single frequency range did not best characterize state across data from all six subjects, though the ability to distinguish awake and SWS states in individual subjects was excellent. Multisegment piecewise linear fits were used to characterize scale-free slopes across the entire frequency range (0.2-200 Hz. These scale-free slopes differed between Awake and SWS states across subjects, particularly at frequencies below 10 Hz and showed little difference at frequencies above 70 Hz. A Multivariate Maximum Likelihood Analysis (MMLA method using the multisegment slope indices successfully categorized ECoG data in most subjects, though individual variation was seen. The ECoG spectrum is not well characterized by a single linear fit across a defined set of frequencies, but is best described by a set of discrete linear fits across the full range of available frequencies. With increasing computational tractability, the use of scale-free slope values to characterize EEG data will have practical value in clinical and research EEG studies.

  19. Structural characterization and properties of superconducting thin films produced by pulsed laser deposition

    International Nuclear Information System (INIS)

    This work deals with the production and characterization of superconducting Bi-Sr-Ca-Cu-O thin films realized by using the pulsed laser deposition technique. The effect of annealing parameters on the structure and quality of the as-deposited and annealed thin films of Bi-Sr-Ca-Cu-O are reported and discussed, as well as of the sintered pellets used as targets. Scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction have been utilized to characterize both the sintered pellets and the thin film. (orig.)

  20. Gelatinized and nongelatinized corn starch/ poly(epsilon-caprolactone blends: characterization by rheological, mechanical and morphological properties

    Directory of Open Access Journals (Sweden)

    Derval S. Rosa

    2004-09-01

    Full Text Available Poly(epsilon-caprolactone/corn starch blends containing 25, 50 and 75 wt.% starch were prepared by mechanical processing and characterized by the melt flow index (MFI, tensile test and scanning electron microscopy (SEM. For comparison, starch was used in gelatinized and nongelatinized forms and was also characterized by viscography. The addition of starch to poly(epsilon-caprolactone reduced the MFI values, the tensile strength and the elongation at break, whereas the modulus increased. The reductions in the MFI and tensile properties were most evident when gelatinized starch was used. Viscography and SEM showed that starch was well gelatinized by the gelatinization process. Blends containing nongelatinized starch showed a good dispersion of starch but poor interfacial interactions.

  1. Nanomechanical characterization of thermo-mechanical properties of irradiated zirconium with consideration of temperature and microstructure

    Science.gov (United States)

    Marsh, Jonathan T.

    Zirconium (Zr) and zirconium-alloys have been utilized in the nuclear industry for decades, most commonly in nuclear fuel cladding. The characteristics which make Zr ideal for these applications include: low density, high hardness, high ductility, and high corrosion resistance. Efforts have been made to further enhance these properties through the use of Zr-alloys, such as Zircaloy-2 and Zircaloy-4, which are made up 95-99% Zr by weight, with the remaining weight percentage being made of other metals (tin, niobium, nickel, iron, chromium). The performance of these materials directly influences the efficiency of the nuclear reactor and are thus of primary concern. While the properties of these materials alone have been studied extensively, the nuclear reactor environment itself serves to degrade or enhance these properties, depending on the situation. The coupled effect of irradiation, high temperature, and microstructure is not understood. Each of these aspects uniquely influence the thermo-mechanical properties of these Zr-based materials and a better understanding of these coupled phenomena is necessary to effectively and efficiently design these nuclear reactor components. The aim of the following work is to experimentally investigate the effect of these coupled phenomena on the thermo-mechanical properties and viscoplastic response of Zr.

  2. Microstructural characterizations and mechanical properties in underwater friction stir welding of aluminum and magnesium dissimilar alloys

    International Nuclear Information System (INIS)

    Highlights: • Aluminum and magnesium alloys were joined by underwater friction stir welding. • Underwater FSW was conducted to improve properties of joint with lower heat input. • Microstructures and mechanical properties of dissimilar joint were investigated. • Intermetallic compounds developed in the fracture interface were analyzed. • Fracture features of the tensile samples were analyzed. - Abstract: Formation of intermetallic compounds in the stir zone of dissimilar welds affects the mechanical properties of the joints significantly. In order to reduce heat input and control the amount and morphological characteristics of brittle intermetallic compounds underwater friction stir welding of 6013 Al alloy and AZ31 Mg alloy was carried out. Microstructures, mechanical properties, elements distribution, and the fracture surface of the joints were analyzed by optical microscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy, etc. The result shows that sound dissimilar joint with good mechanical properties can be obtained by underwater friction stir welding. Al and Mg alloys were stirred together and undergone the process of recrystallization, forming complex intercalated flow patterns in the stir zone. Tensile strength of the dissimilar joint was up to 152.3 MPa. Maximum hardness (142HV) appeared in the middle of the centerline of the specimen. Intermetallic compounds layer consisting of Al3Mg2 and Mg17Al12 formed in the Al/Mg interface and resulted in the fracture of the joint

  3. Purification, Characterization and Analysis of the Allergenic Properties of Myosin Light Chain in Procambarus clarkia.

    Science.gov (United States)

    Myosin light chain (MLC) plays a vital role in cell and muscle functions and has been identified as an allergen in close species. In this study, MLC with the molecular mass of 18kDa was purified from crayfish (Procambarus clarkii) muscle fibrils. Its physicochemical characterization showed that the...

  4. Synthesis, Characterization and Evaluation of Physical Properties of Biodegradable Composites from Corn Starch

    OpenAIRE

    Sanjay Kumar; Deepak Prashar

    2012-01-01

    This research paper deals with the synthesis and characterization of corn starch based composites using resorcinol-formaldehyde as cross linker. Acid, base and moisture resistance studies of the composites were also done. Moreover, biodegradation studies of the composites were also done using composting method and the different stages of the biodegradation were evaluated using scanning electron microscopy.

  5. Clay Characterization as Engineered Barrier to Contaminants Migration: Thermal, Hydraulic and Mechanical Properties

    International Nuclear Information System (INIS)

    In this work we characterize the structure of a clay, concretely bentonite. Our main aim is to stress the important role that plays the heterogeneity of the medium structure in transport processes. Randomness of pore sizes produces an anomalous transport of contaminants. We analyze mercuric porosimetry data with simulations finding that pore size distribution has a power-law behaviour. (Author) 6 refs

  6. Characterization of chemical, biological and antiproliferative properties of fermented black carrot juice, shalgam

    Science.gov (United States)

    Shalgam juice is a dark red-colored and sour fermented beverage produced and consumed in Turkey. The main ingredient of shalgam juice is black carrot, which is rich in anthocyanins. In this study, commercially available shalgam juice was characterized by determining its chemical composition and anti...

  7. Characterization of the mechanical properties and structural integrity of T-welded connections repaired by grinding and wet welding

    International Nuclear Information System (INIS)

    This paper presents an experimental methodology to characterize the structural integrity and mechanical properties of repaired T-welded connections using in fixed offshore structures. Grinding is employed to remove localized damage like cracking and corrosion and subsequent wet welding can be used to fill the grinded material. But it is important to define the grinding depth and profile in order to maintain structural integrity during the repair. Therefore, in this work different grinding depths were performed, for damage material removal, at the weld toe of the T-welded connections. The grinding was filled by wet welding in a hyperbaric chamber, simulating three different water depths: 50 m, 70 m and 100 m. The electrodes were coated with vinilic varnish, which is cheap and easy to apply. The characterization of the mechanical properties of the T-welded connections was done with standard tensile, hardness and Charpy tests; microstructure and porosity analysis were also performed. The samples were obtained from the welded connections in regions of the wet weld beads. The test results were compared with the mechanical properties of the T-welded connections welded in air conditions performed by other authors. The results showed that the wet welding technique performed in this work produced good mechanical properties of the repaired T-welded connection. The mechanical properties, measured in wet conditions, for 6 mm grinding depth, were similar for the 3 different water depths measured in air conditions. But for 10 mm grinding depth, the values of the mechanical properties measured in wet conditions were quite lower than that for air conditions for the 3 water depths. However a porosity analysis, performed with a Scanning Electronic Microscopy (SEM), showed that the level of porosity in the resulted wet weld beads is in the range of that published in the literature and some samples revealed lower level of porosity. The main resulting microstructure was polygonal

  8. Characterization of the mechanical properties and structural integrity of T-welded connections repaired by grinding and wet welding

    Energy Technology Data Exchange (ETDEWEB)

    Terán, G., E-mail: gteran@imp.mx [Instituto Mexicano del Petróleo, Eje central Lázaro Cárdenas 152, Col. San Bartolo Atepehuacan, México D.F. CP 07730, México (Mexico); Cuamatzi-Meléndez, R., E-mail: rcuamatzi@imp.mx [Instituto Mexicano del Petróleo, Eje central Lázaro Cárdenas 152, Col. San Bartolo Atepehuacan, México D.F. CP 07730, México (Mexico); Albiter, A., E-mail: aalbiter@imp.mx [Instituto Mexicano del Petróleo, Eje central Lázaro Cárdenas 152, Col. San Bartolo Atepehuacan, México D.F. CP 07730, México (Mexico); Maldonado, C., E-mail: cmzepeda@umich.mx [Instituto de Investigaciones Metalúrgicas, UMSNH, PO Box 52-B, 58000, México (Mexico); Bracarense, A.Q., E-mail: bracarense@ufmg.br [UFMG Departamento de Engeharia Mecánica Belo Horizonte, MG (Brazil)

    2014-04-01

    This paper presents an experimental methodology to characterize the structural integrity and mechanical properties of repaired T-welded connections using in fixed offshore structures. Grinding is employed to remove localized damage like cracking and corrosion and subsequent wet welding can be used to fill the grinded material. But it is important to define the grinding depth and profile in order to maintain structural integrity during the repair. Therefore, in this work different grinding depths were performed, for damage material removal, at the weld toe of the T-welded connections. The grinding was filled by wet welding in a hyperbaric chamber, simulating three different water depths: 50 m, 70 m and 100 m. The electrodes were coated with vinilic varnish, which is cheap and easy to apply. The characterization of the mechanical properties of the T-welded connections was done with standard tensile, hardness and Charpy tests; microstructure and porosity analysis were also performed. The samples were obtained from the welded connections in regions of the wet weld beads. The test results were compared with the mechanical properties of the T-welded connections welded in air conditions performed by other authors. The results showed that the wet welding technique performed in this work produced good mechanical properties of the repaired T-welded connection. The mechanical properties, measured in wet conditions, for 6 mm grinding depth, were similar for the 3 different water depths measured in air conditions. But for 10 mm grinding depth, the values of the mechanical properties measured in wet conditions were quite lower than that for air conditions for the 3 water depths. However a porosity analysis, performed with a Scanning Electronic Microscopy (SEM), showed that the level of porosity in the resulted wet weld beads is in the range of that published in the literature and some samples revealed lower level of porosity. The main resulting microstructure was polygonal

  9. Synthesis, characterization, photo and physicochemical properties of 11-mercaptoundecanoic acid and tetraaniline capped CdS quantum dots

    International Nuclear Information System (INIS)

    Surface modification of quantum dots (QDs) for improved photo and physicochemical properties is a topic of potential technological interest. Herein, we report on the synthesis of aggregation free 11-mercaptoundecanoic acid and tetraaniline (TA) capped CdS QDs with narrow size distribution (∼2.3 nm diameter), which are further characterized using UV-visible spectroscopy, photoluminescence spectroscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. The TA capped CdS QDs show improved photoluminescence and photostability, which is attributed to the effective grafting of TA on CdS QDs through N-atoms, changing the surface chemical environment and facilitating charge transfer.

  10. Synthesis, characterization, photo and physicochemical properties of 11-mercaptoundecanoic acid and tetraaniline capped CdS quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wen-Yin [Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Ghule, Anil Vithal, E-mail: anighule@gmail.com [Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Chang, Jia-Yaw; Chen, Bo-Jung; Liu, Jen-Yu; Tzing, Shin-Hwa [Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Ling, Yong-Chien, E-mail: ycling@mx.nthu.edu.tw [Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

    2010-10-01

    Surface modification of quantum dots (QDs) for improved photo and physicochemical properties is a topic of potential technological interest. Herein, we report on the synthesis of aggregation free 11-mercaptoundecanoic acid and tetraaniline (TA) capped CdS QDs with narrow size distribution ({approx}2.3 nm diameter), which are further characterized using UV-visible spectroscopy, photoluminescence spectroscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. The TA capped CdS QDs show improved photoluminescence and photostability, which is attributed to the effective grafting of TA on CdS QDs through N-atoms, changing the surface chemical environment and facilitating charge transfer.

  11. Spin glass: thermal properties and characterization of the ± J Sherrington-Kirkpatrick model partition function zeros

    International Nuclear Information System (INIS)

    A detailed study of the S-K model through the analysis of the zeros of the partition function in the complex temperature plane is performed. By the exact way, the notable thermodynamical properties of the system to a variety of the length (N=5→25 spins) are calculated, using only standards concepts (without the use of tricks like that of replicas). Dilute models had been also considered. The principal result of this work is the characterization of the zeros of the partition function of the S-K model. (author)

  12. Characterization of biological and antigenic properties of raccoon dog and blue fox parvoviruses: a monoclonal antibody study.

    Science.gov (United States)

    Veijalainen, P

    1988-03-01

    Parvovirus isolates from blue foxes and raccoon dogs were characterized by studying their haemagglutination properties, host range in vitro and antigenic structure. In all 3 characters, raccoon dog parvovirus resembled canine parvovirus (CPV), while blue fox parvovirus was similar to mink enteritis virus (MEV). Monoclonal antibodies (MAbs) were prepared against both viruses. Raccoon dog parvovirus, while resembling CPV, had a unique antigenic site which could be specified by MAbs. The pattern of MAbs prepared against blue fox parvovirus indicated that it is a member of Type 2 MEV. PMID:2836994

  13. Preparation and characterization of electrospun poly(phthalazinone ether nitrile ketone) membrane with novel thermally stable properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Gang; Zhang, Hao; Qian, Bingqing [Carbon Research Laboratory, Liaoning Key Lab for Energy Materials and Chemical Engineering, State Key Lab of Fine Chemicals, Dalian University of Technology, Dalian 116024 (China); Wang, Jinyan, E-mail: wangjinyan@dlut.edu.cn [Department of Polymer Science and Materials, Dalian University of Technology, Dalian 116024 (China); Jian, Xigao [Department of Polymer Science and Materials, Dalian University of Technology, Dalian 116024 (China); Qiu, Jieshan, E-mail: jqiu@dlut.edu.cn [Carbon Research Laboratory, Liaoning Key Lab for Energy Materials and Chemical Engineering, State Key Lab of Fine Chemicals, Dalian University of Technology, Dalian 116024 (China)

    2015-10-01

    Highlights: • Poly (phthalazinone ether nitrile ketone) (PPENK) was used to successfully prepare nanofiber membranes by electrospinning. • Electrospun membrane exhibits a good thermostability. • Electrospun membrane. - Abstract: Electrospun nanofibrous membranes have several applications because of their excellent properties, such as high porosity, small fiber diameter, and large surface area. However, high-temperature resistant electrospun membranes remain a challenge because of the absence of precursors that offer spinnability, scalability, and superior thermal stability. In this study, poly(phthalazinone ether nitrile ketone) (PPENK) was used to successfully prepare nanofiber membranes by electrospinning. Electrospun PPENK membranes were characterized by scanning electron microscopy, differential scanning calorimetry, Fourier transform infrared spectroscopy, and tensile stress–strain tests. Results indicated that the prepared electrospun membranes had a very high glass transition temperature, superior chemical resistance, and excellent mechanical strength. These desirable properties broaden their potential application in membranes and treatment of various hot fluid streams without strict temperature control.

  14. Fracture Toughness, Mechanical Property, And Chemical Characterization Of A Critical Modification To The NASA SLS Solid Booster Internal Material System

    Science.gov (United States)

    Pancoast, Justin; Garrett, William; Moe, Gulia

    2015-01-01

    A modified propellant-liner-insulation (PLI) bondline in the Space Launch System (SLS) solid rocket booster required characterization for flight certification. The chemical changes to the PLI bondline and the required additional processing have been correlated to mechanical responses of the materials across the bondline. Mechanical properties testing and analyses included fracture toughness, tensile, and shear tests. Chemical properties testing and analyses included Fourier transform infrared (FTIR) spectroscopy, cross-link density, high-performance liquid chromatography (HPLC), gas chromatography (GC), gel permeation chromatography (GPC), and wave dispersion X-ray fluorescence (WDXRF). The testing identified the presence of the expected new materials and found the functional bondline performance of the new PLI system was not significantly changed from the old system.

  15. Synthesis, characterization and gas sensing properties of flowerlike In{sub 2}O{sub 3} composed of microrods

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Xifeng [State Key Lab of Crystal Materials, Shandong University, Jinan (China); Lunan Institute of Coal Chemical Engineering, Jining (China); State Quality inspection Center of Coal and Coal Chemical Product, Jining (China); Yu, Qinqin; Wang, Kang; Wang, Lei [State Key Lab of Crystal Materials, Shandong University, Jinan (China); Shi, Luchuan; Liu, Xing; Qiu, Aiguo [Lunan Institute of Coal Chemical Engineering, Jining (China); State Quality inspection Center of Coal and Coal Chemical Product, Jining (China); Cui, Deliang

    2010-05-15

    Flowerlike structured In{sub 2}O{sub 3} were successfully synthesized via a hydrothermal process and the subsequent calcinations. The obtained sample consists of microrods with an average diameter of 0.5-1{mu}m and a length of 1-3{mu}m. Structure and property of the sample were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The sensing properties towards trimethylamine (TMA) were examined at 200-400 C, which showed high sensitivity, better selectivity, and prompt response/recovery merits. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Characterization of mechanical properties of hybrid contrast agents by combining atomic force microscopy with acoustic/optic assessments.

    Science.gov (United States)

    Guo, Gepu; Tu, Juan; Guo, Xiasheng; Huang, Pintong; Wu, Junru; Zhang, Dong

    2016-02-01

    Multi-parameter fitting algorithms, which are currently used for the characterization of coated-bubbles, inevitably introduce uncertainty into the results. Therefore, a better technique that can accurately determine the microbubbles׳ mechanical properties is urgently needed. A comprehensive technology combining atomic force microscopy, optical, and acoustic measurements with simulations of coated-bubble dynamics was developed. Using this technique, the mechanical parameters (size distribution, shell thickness, elasticity, and viscosity) of hybrid (ultrasound/magnetic-resonance-imaging) contrast microbubbles and their structure-property relationship were determined. The measurements indicate that when more superparamagnetic iron oxide nanoparticles are embedded in the microbubbles׳ shells, their mean diameter and effective viscosity increase, and their elastic modulus decreases. This reduces the microbubbles׳ resonance frequency and thus enhances acoustic scattering and attenuation effects. PMID:26726783

  17. Preparation and characterization of electrospun poly(phthalazinone ether nitrile ketone) membrane with novel thermally stable properties

    International Nuclear Information System (INIS)

    Highlights: • Poly (phthalazinone ether nitrile ketone) (PPENK) was used to successfully prepare nanofiber membranes by electrospinning. • Electrospun membrane exhibits a good thermostability. • Electrospun membrane. - Abstract: Electrospun nanofibrous membranes have several applications because of their excellent properties, such as high porosity, small fiber diameter, and large surface area. However, high-temperature resistant electrospun membranes remain a challenge because of the absence of precursors that offer spinnability, scalability, and superior thermal stability. In this study, poly(phthalazinone ether nitrile ketone) (PPENK) was used to successfully prepare nanofiber membranes by electrospinning. Electrospun PPENK membranes were characterized by scanning electron microscopy, differential scanning calorimetry, Fourier transform infrared spectroscopy, and tensile stress–strain tests. Results indicated that the prepared electrospun membranes had a very high glass transition temperature, superior chemical resistance, and excellent mechanical strength. These desirable properties broaden their potential application in membranes and treatment of various hot fluid streams without strict temperature control

  18. Chromatographic Retention Times of Polychlorinated Biphenyls: from Structural Information to Property Characterization

    Directory of Open Access Journals (Sweden)

    Mircea V. Diudea

    2006-11-01

    Full Text Available The paper presents a unitary approach of the use of a Molecular DescriptorsFamily in structure-property/activity relationships, particularly in modelling thechromatographic retention times of polychlorinated biphenyls. Starting from molecularstructure, viewed as a graph, and considering the bonds and bond types, atom types andoften the 3D geometry of the molecule, a huge family of molecular descriptors called MDFwas calculated. A preliminary selection of MDF members was done by simple linearregression (LR against the measured property. The best fitted MDF subset is thensubmitted to multivariate linear regression (MLR analysis in order to find the best pairs ofMDF members that produce a reliable QSPR (Quantitative Structure-PropertyRelationship model. The predictive capability was finally tested by randomly splitting ofdata into training and test sets. The best obtained models are presented and the results arediscussed.

  19. Characterization of structural and functional properties of fish protein hydrolysates from surimi processing by-products.

    Science.gov (United States)

    Liu, Yongle; Li, Xianghong; Chen, Zhijun; Yu, Jian; Wang, Faxiang; Wang, Jianhui

    2014-05-15

    Structural and functional properties of fish protein hydrolysates with different degrees of hydrolysis (DH) from surimi processing by-products, prepared by Protamex and Alcalase, were evaluated. As the DH increased, the zeta potentials of the hydrolysates increased (p>0.05). The surface hydrophobicity of the hydrolysates was significantly affected by DH (phydrolysate with DH 10%, prepared by Protamex, contained more large protein molecules than did the others. Hydrolysis by both enzymes increased solubility to more than 65% over a wide pH range (pH 2-10). The interfacial activities of hydrolysates decreased with increasing DH (phydrolysate with DH 10%, prepared by Protamex, exhibited the best interfacial properties among all of the samples. Thermal properties were also affected by the hydrolysis. The results reveal that structures and functionalities of the hydrolysates were determined both by DH and enzyme type employed. PMID:24423557

  20. Excited State Properties of Fluorine-Substituted Hexabenzocoronene: A Quantum-Chemical Characterization

    Institute of Scientific and Technical Information of China (English)

    LI Yuan-Zuo; SUN Yu; LI Yong-Qing; MA Feng-Cai

    2006-01-01

    The first fluorine-substituted hexabenzocoronene has been synthesized and its electronic structure and optical properties have been reported [Q. Zhang, et al., Org. Lett.7 (2005) 5019]. In this letter, the electronic structure and excited state properties of the fluorine-substituted hexabenzocoronene are studied with quantum chemistry method as well as the transition and the charge difference densities. The transition densities show the orientations and strength of the dipole moments and the charge difference densities reveal the orientation and results of the intramolecular charge transfer. The calculated transition energies and oscillator strengths are consistent with the experimental data, and the theoretical results of transition and charge difference densities are valuable to understanding the excited state properties of the fluorine-substituted hexabenzocoronene.

  1. Nanoscale characterization of the biomechanical properties of collagen fibrils in the sclera

    Energy Technology Data Exchange (ETDEWEB)

    Papi, M. [Institute of Physics, Università Cattolica del Sacro Cuore, Largo F.Vito 1, 00168 Rome (Italy); Paoletti, P. [Centre for Engineering Dynamics, School of Engineering, Brownlow Hill, Liverpool, L69 3GH (United Kingdom); Geraghty, B.; Akhtar, R. [Centre for Materials and Structures, School of Engineering, Brownlow Hill, Liverpool, L69 3GH (United Kingdom)

    2014-03-10

    We apply the PeakForce Quantitative Nanomechanical Property Mapping (PFQNM) atomic force microscopy mode for the investigation of regional variations in the nanomechanical properties of porcine sclera. We examine variations in the collagen fibril diameter, adhesion, elastic modulus and dissipation in the posterior, equatorial and anterior regions of the sclera. The mean fibril diameter, elastic modulus and dissipation increased from the posterior to the anterior region. Collagen fibril diameter correlated linearly with elastic modulus. Our data matches the known macroscopic mechanical behavior of the sclera. We propose that PFQNM has significant potential in ocular biomechanics and biophysics research.

  2. Characterization of Physical, Thermal and Structural Properties of Chromium (VI) Oxide Powder: Impact of Biofield Treatment

    OpenAIRE

    Trivedi, Mahendra; Branton, Alice; Trivedi, Dahryn; Nayak, Gopal

    2015-01-01

    Chromium (VI) oxide (CrO3) has gained extensive attention due to its versatile physical and chemical properties. The objective of the present study was to evaluate the impact of biofield treatment on physical, thermal and structural properties of CrO3 powder. In this study, CrO3 powder was divided into two parts i.e. control and treatment. Control part was remained as untreated and treated part received Mr. Trivedi’s biofield treatment. Subsequently, control and treated CrO3 samples were char...

  3. Measured and theoretical characterization of the RF properties of stacked, high-gradient insulator material

    Energy Technology Data Exchange (ETDEWEB)

    Houck, T. L., LLNL

    1997-05-09

    Recent high-voltage breakdown experiments of periodic metallic-dielectric insulating structures have suggested several interesting high-gradient applications. One such area is the employment of high-gradient insulators in high-current, electron-beam, accelerating induction modules. For this application, the understanding of the rf characteristics of the insulator plays an important role in estimating beam-cavity interactions. In this paper, we examine the rf properties of the insulator comparing simulation results with experiment. Different insulator designs are examined to determine their rf transmission properties in gap geometries.

  4. Chemical characterization and bioactive properties of Geranium molle L.: from the plant to the most active extract and its phytochemicals.

    Science.gov (United States)

    Graça, V C; Barros, Lillian; Calhelha, Ricardo C; Dias, Maria Inês; Carvalho, Ana Maria; Santos-Buelga, Celestino; Ferreira, Isabel C F R; Santos, P F

    2016-05-18

    After a period of indifference, in which synthetic compounds were favored, there is an increasing interest in the study of the biological properties of plants and the active principles responsible for their therapeutic properties. Geranium molle L. has been used in the Portuguese folk medicine for the treatment of various ailments including cancer but, unlike many of the species from the Geranium genus, its phytochemical characterization and biological activity are virtually unexplored. In this study a G. molle sample from Trás-os-Montes, north-eastern Portugal, was chemically characterized regarding nutritional value, free sugars, organic acids, fatty acids and tocopherols, and several aqueous (decoction, infusion) and organic (n-hexane, dichloromethane, ethyl acetate, acetone, methanol) extracts of the plant were assessed for their bioactive properties. The antioxidant activity was evaluated by means of the free radicals scavenging activity, reducing power and inhibition of lipid peroxidation. The cytotoxicity of the different extracts was assessed in vitro against several human cancer cell lines (breast, lung, cervical and hepatocellular carcinomas) and, additionally, their hepatotoxicity was evaluated using a porcine liver primary cell culture. G. molle was shown to be rich in carbohydrates and proteins, providing tocopherols and essential fatty acids. Amongst the various extracts, the acetone extract was found to have the highest content of phenolic compounds (mainly ellagitannins, but also some flavone and flavonol glycosides) as well as the highest antioxidant and cytotoxic activities. To the best of our knowledge, this is the first report on the chemical composition and bioactive properties of G. molle. PMID:27094513

  5. Preparation, characterization and latent heat thermal energy storage properties of micro-nanoencapsulated fatty acids by polystyrene shell

    International Nuclear Information System (INIS)

    This work deals with the synthesis, physico-chemical characterization and latent heat thermal energy storage (LHTES) properties of micro-nanoencapsulated capric, lauric and myristic acids with polystyrene (PS) by using emulsion polymerization method. In synthesized micro-nanocapsules, the fatty acid has a function of phase change material (PCM) while PS acts as a shell material. The micro-nanoencapsulated PCMs (M-NEPCMs) were characterized chemically and morphologically by using Fourier transform infrared (FT-IR) spectroscopy, particle size distribution (PSD), and polarized optical microscopy (POM) and scanning electron microscopy (SEM) analyses methods. Differential scanning calorimeter (DSC) analysis showed that the fabricated M-NEPCMs melt and freeze in the temperature range of 22–48 °C and 19–49 °C as they storage and release a latent heat in range of 87–98 J/g and (−84) J/g–(−96) J/g. The M-NEPCMs were subjected to a thermal cycling test consisted with 5000 heating/cooling processes and the results revealed that their LHTES properties were changed slightly. The M-NEPCMs had good thermal durability and reasonable thermal conductivity values. These advantageous properties make them potential LHTES materials for thermal regulating, solar heat pumps and solar space heating–cooling applications in buildings. - Graphical abstract: This work is focused on the synthesis, physico-chemical characterization and determination of latent heat thermal energy storage (LHTES) properties of micro-nanoencapsulated some fatty acids (capric, lauric and myristic acids) with polystyrene (PS) by using emulsion polymerization method. The obtained all results that the prepared M-NEPCMs have high potential for different thermal energy storage systems due to their good LHTES and morphological properties, thermal and chemical stability. - Highlights: • The chemical structures of the M-NEPCMs were verified using FTIR spectroscopy. • The prepared spherical capsules

  6. Property-based design: optimization and characterization of polyvinyl alcohol (PVA) hydrogel and PVA-matrix composite for artificial cornea.

    Science.gov (United States)

    Jiang, Hong; Zuo, Yi; Zhang, Li; Li, Jidong; Zhang, Aiming; Li, Yubao; Yang, Xiaochao

    2014-03-01

    Each approach for artificial cornea design is toward the same goal: to develop a material that best mimics the important properties of natural cornea. Accordingly, the selection and optimization of corneal substitute should be based on their physicochemical properties. In this study, three types of polyvinyl alcohol (PVA) hydrogels with different polymerization degree (PVA1799, PVA2499 and PVA2699) were prepared by freeze-thawing techniques. After characterization in terms of transparency, water content, water contact angle, mechanical property, root-mean-square roughness and protein adsorption behavior, the optimized PVA2499 hydrogel with similar properties of natural cornea was selected as a matrix material for artificial cornea. Based on this, a biomimetic artificial cornea was fabricated with core-and-skirt structure: a transparent PVA hydrogel core, surrounding by a ringed PVA-matrix composite skirt that composed of graphite, Fe-doped nano hydroxyapatite (n-Fe-HA) and PVA hydrogel. Different ratio of graphite/n-Fe-HA can tune the skirt color from dark brown to light brown, which well simulates the iris color of Oriental eyes. Moreover, morphologic and mechanical examination showed that an integrated core-and-skirt artificial cornea was formed from an interpenetrating polymer network, no phase separation appeared on the interface between the core and the skirt. PMID:24464723

  7. Spatial characterization of soil properties and influence in soil formation in oak-grassland of Sierra Morena, S Spain

    Science.gov (United States)

    Román-Sánchez, Andrea; Cáceres, Francisco; Pédèches, Remi; Giráldez Cervera, Juan Vicente; Vanwalleghem, Tom

    2016-04-01

    The Mediterranean oak-grassland ecosystem is very important for the rural economy and for the biodiversity of south-western European countries like Spain and Portugal. Nevertheless these ecosystems are not well characterized especially their soils. In this report soil carbon has been evaluated and related to other properties. The principal factors controlling the structure, productivity and evolution of forest ecosystems are bedrock, climate, relief, vegetation and time. Soil carbon has an important influence in the soil and ecosystem structures. The purpose of this study is to determine the relationship between relief, soil properties, spatial distribution of soil carbon and their influence in soil formation and geomorphology. This work is part of another study which aims to elucidate the processes involved in the soil formation and to examine their behaviour on long-term with a modelling. In our study area, located in oak-grassland of Sierra Morena, in Cordoba, S Spain, have been studied 67 points at 6 depths in 262 hectares in order to determine carbon content varying between 0-6%, soil properties such as soil depth between 0-4 m, horizon depth and the rocks amount in surface. The relationship between the soil carbon, soil properties and the relief characteristic like slope, aspect, curvature can shed light the processes that affect the mechanisms of bedrock weathering and their interrelationship with geomorphological processes.

  8. Thermophysical properties and corrosion characterization of low cost lithium containing nitrate salts produced in northern Chile for thermal energy storage

    Science.gov (United States)

    Fernández, Ángel G.; Gomez, Judith C.; Galleguillos, Hector; Fuentealba, Edward

    2016-05-01

    In recent years, lithium containing salts have been studied for thermal energy storage (TES) systems applications, because of their optimal thermophysical properties. In solar power plants, lithium is seen as a way to improve the properties of molten salts used today. Lithium nitrate is a good candidate for sensible heat storage, due to its ability to increase the salt mixture's working temperature range. In the present research, thermophysical properties characterization of lithium nitrate containing salts, produced in Chile, have been carried out. Corrosion evaluations of carbon and low chromium steels were performed at 390°C for 1000 hours. Thermophysical properties of the salt mixtures, such as thermal stability and heat capacity, were measured before and after corrosion tests. Chemical composition of the salts was also determined and an estimation of Chilean production costs is reported. Results showed that purity, thermal stability and heat capacity of the salts were reduced, caused by partial thermal decomposition and incorporation of corrosion products from the steel.

  9. Thermophysical Properties and Corrosion Characterization of Low Cost Lithium Containing Nitrate Salts Produced in Northern Chile for Thermal Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, Angel G.; Gomez, Judith C.; Galleguillos, Hector; Fuentealba, Edward

    2016-05-31

    In recent years, lithium containing salts have been studied for thermal energy storage (TES) systems applications, because of their optimal thermophysical properties. In solar power plants, lithium is seen as a way to improve the properties of molten salts used today. Lithium nitrate is a good candidate for sensible heat storage, due to its ability to increase the salt mixture's working temperature range. In the present research, thermophysical properties characterization of lithium nitrate containing salts, produced in Chile, have been carried out. Corrosion evaluations of carbon and low chromium steels were performed at 390 degrees C for 1000 hours. Thermophysical properties of the salt mixtures, such as thermal stability and heat capacity, were measured before and after corrosion tests. Chemical composition of the salts was also determined and an estimation of Chilean production costs is reported. Results showed that purity, thermal stability and heat capacity of the salts were reduced, caused by partial thermal decomposition and incorporation of corrosion products from the steel.

  10. One step forward toward characterization: some important material properties to distinguish biochars.

    Science.gov (United States)

    Schimmelpfennig, Sonja; Glaser, Bruno

    2012-01-01

    Terra Preta research gave evidence for the positive influence of charred organic material (biochar) on infertile tropical soils. Facing global challenges such as land degradation, fossil energy decline, water shortage, and climate change, the use of biochar as a soil amendment embedded into regional matter cycles seems to provide an all-round solution. However, little is known about biochar effects on individual ecosystem processes. Besides, the term is used for a variety of charred products. Therefore, the aim of this study was to investigate principal material properties of different chars to establish a minimum set of analytical properties and thresholds for biochar identification. For this purpose, chars from different production processes (traditional charcoal stack, rotary kiln, Pyreg reactor, wood gasifier, and hydrothermal carbonization) were analyzed for physical and chemical properties such as surface area, black carbon, polycyclic aromatic hydrocarbons, and elemental composition. Our results showed a significant influence of production processes on biochar properties. Based on our results, to identify biochar suitable for soil amendment and carbon sequestration, we recommend using variables with the following thresholds: O/C ratio 15% C, polyaromatic hydrocarbons lower than soil background values, and a surface area >100 m g. PMID:22751042

  11. Impact of carbonation on the durability of cementitious materials: water transport properties characterization

    Directory of Open Access Journals (Sweden)

    Le Bescop P.

    2013-07-01

    Full Text Available Within the context of long-lived intermediate level radioactive waste geological disposal, reinforced concrete would be used. In service life conditions, the concrete structures would be subjected to drying and carbonation. Carbonation relates to the reaction between carbon dioxide (CO2 and the main hydrates of the cement paste (portlandite and C-S-H. Beyond the fall of the pore solution pH, indicative of steel depassivation, carbonation induces mineralogical and microstructural changes (due to portlandite and C-S-H dissolution and calcium carbonate precipitation. This results in the modification of the transport properties, which can impact the structure durability. Because concrete durability depends on water transport, this study focuses on the influence of carbonation on water transport properties. In fact, the transport properties of sound materials are known but they still remain to be assessed for carbonated ones. An experimental program has been designed to investigate the transport properties in carbonated materials. Four hardened cement pastes, differing in mineralogy, are carbonated in an accelerated carbonation device (in controlled environmental conditions at CO2 partial pressure of about 3%. Once fully carbonated, all the data needed to describe water transport, using a simplified approach, will be evaluated.

  12. Impact of carbonation on the durability of cementitious materials: water transport properties characterization

    Science.gov (United States)

    Auroy, M.; Poyet, S.; Le Bescop, P.; Torrenti, J.-M.

    2013-07-01

    Within the context of long-lived intermediate level radioactive waste geological disposal, reinforced concrete would be used. In service life conditions, the concrete structures would be subjected to drying and carbonation. Carbonation relates to the reaction between carbon dioxide (CO2) and the main hydrates of the cement paste (portlandite and C-S-H). Beyond the fall of the pore solution pH, indicative of steel depassivation, carbonation induces mineralogical and microstructural changes (due to portlandite and C-S-H dissolution and calcium carbonate precipitation). This results in the modification of the transport properties, which can impact the structure durability. Because concrete durability depends on water transport, this study focuses on the influence of carbonation on water transport properties. In fact, the transport properties of sound materials are known but they still remain to be assessed for carbonated ones. An experimental program has been designed to investigate the transport properties in carbonated materials. Four hardened cement pastes, differing in mineralogy, are carbonated in an accelerated carbonation device (in controlled environmental conditions) at CO2 partial pressure of about 3%. Once fully carbonated, all the data needed to describe water transport, using a simplified approach, will be evaluated.

  13. Synthesis and characterization of biodegradable lignin nanoparticles with tunable surface properties

    NARCIS (Netherlands)

    Richter, Alexander P.; Bharti, Bhuvnesh; Armstrong, Hinton B.; Brown, Joseph S.; Plemmons, Dayne; Paunov, Vesselin N.; Stoyanov, Simeon D.; Velev, Orlin D.

    2016-01-01

    Lignin nanoparticles can serve as biodegradable carriers of biocidal actives with minimal environmental footprint. Here we describe the colloidal synthesis and interfacial design of nanoparticles with tunable surface properties using two different lignin precursors, Kraft (Indulin AT) lignin and

  14. Synthesis and Characterization of Biodegradable Lignin Nanoparticles with Tunable Surface Properties.

    Science.gov (United States)

    Richter, Alexander P; Bharti, Bhuvnesh; Armstrong, Hinton B; Brown, Joseph S; Plemmons, Dayne; Paunov, Vesselin N; Stoyanov, Simeon D; Velev, Orlin D

    2016-06-28

    Lignin nanoparticles can serve as biodegradable carriers of biocidal actives with minimal environmental footprint. Here we describe the colloidal synthesis and interfacial design of nanoparticles with tunable surface properties using two different lignin precursors, Kraft (Indulin AT) lignin and Organosolv (high-purity lignin). The green synthesis process is based on flash precipitation of dissolved lignin polymer, which enabled the formation of nanoparticles in the size range of 45-250 nm. The size evolution of the two types of lignin particles is fitted on the basis of modified diffusive growth kinetics and mass balance dependencies. The surface properties of the nanoparticles are fine-tuned by coating them with a cationic polyelectrolyte, poly(diallyldimethylammonium chloride). We analyze how the colloidal stability and dispersion properties of these two types of nanoparticles vary as a function of pH and salinities. The data show that the properties of the nanoparticles are governed by the type of lignin used and the presence of polyelectrolyte surface coating. The coating allows the control of the nanoparticles' surface charge and the extension of their stability into strongly basic regimes, facilitating their potential application at extreme pH conditions. PMID:27268077

  15. Isolation, Characterization, and Surfactant Properties of the Major Triterpenoid Glycosides from Unripe Tomato Fruits

    NARCIS (Netherlands)

    Yamanaka, T.; Vincken, J.P.; Waard, de P.; Sanders, M.G.; Takada, N.; Gruppen, H.

    2008-01-01

    Various triterpenoid glycosides were extracted from whole unripe tomato fruits (Lycopersicon esculentum cv. Cedrico), using aqueous 70% (v/v) ethanol to study their surfactant properties. Cation-exchange chromatography using a Source 15S column and subsequent semipreparative HPLC using an XTerra RP1

  16. Characterization of real gas properties for space shuttle main engine fuel turbine and performance calculations

    Science.gov (United States)

    Harloff, G. J.

    1986-01-01

    Real thermodynamic and transport properties of hydrogen, steam, the SSME mixture, and air are developed. The SSME mixture properties are needed for the analysis of the space shuttle main engine fuel turbine. The mixture conditions for the gases, except air, are presented graphically over a temperature range from 800 to 1200 K, and a pressure range from 1 to 500 atm. Air properties are given over a temperature range of 320 to 500 K, which are within the bounds of the thermodynamics programs used, in order to provide mixture data which is more easily checked (than H2/H2O). The real gas property variation of the SSME mixture is quantified. Polynomial expressions, needed for future computer analysis, for viscosity, Prandtl number, and thermal conductivity are given for the H2/H2O SSME fuel turbine mixture at a pressure of 305 atm over a range of temperatures from 950 to 1140 K. These conditions are representative of the SSME turbine operation. Performance calculations are presented for the space shuttle main engine (SSME) fuel turbine. The calculations use the air equivalent concept. Progress towards obtaining the capability to evaluate the performance of the SSME fuel turbine, with the H2/H2O mixture, is described.

  17. Impact of carbonation on the durability of cementitious materials: Water transport properties characterization

    International Nuclear Information System (INIS)

    Within the context of long-lived intermediate level radioactive waste geological disposal, reinforced concrete would be used. In service life conditions, the concrete structures would be subjected to drying and carbonation. Carbonation relates to the reaction between carbon dioxide (CO2) and the main hydrates of the cement paste (portlandite and C-S-H). Beyond the fall of the pore solution pH, indicative of steel depassivation, carbonation induces mineralogical and microstructural changes (due to portlandite and C-S-H dissolution and calcium carbonate precipitation). This results in the modification of the transport properties, which can impact the structure durability. Because concrete durability depends on water transport, this study focuses on the influence of carbonation on water transport properties. In fact, the transport properties of sound materials are known but they still remain to be assessed for carbonated ones. An experimental program has been designed to investigate the transport properties in carbonated materials. Four hardened cement pastes, differing in mineralogy, are carbonated in an accelerated carbonation device (in controlled environmental conditions) at CO2 partial pressure of about 3%. Once fully carbonated, all the data needed to describe water transport, using a simplified approach, will be evaluated. (authors)

  18. Synthesis, Characterization, and Microwave Absorption Properties of Reduced Graphene Oxide/Strontium Ferrite/Polyaniline Nanocomposites.

    Science.gov (United States)

    Luo, Juhua; Shen, Pan; Yao, Wei; Jiang, Cuifeng; Xu, Jianguang

    2016-12-01

    Strontium ferrite nanoparticles were prepared by a coprecipitation method, and reduced graphene oxide/strontium ferrite/polyaniline (R-GO/SF/PANI) ternary nanocomposites were prepared by in situ polymerization method. The morphology, structure, and magnetic properties of the ternary nanocomposites were investigated by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), TEM, Raman, and VSM. The microwave-absorbing properties of the composites were measured by a vector network analyzer. The XRD patterns show the single phase of strontium hexaferrite without other intermediate phases. TEM photographs reveal that strontium ferrite nanoparticles are uniformly dispersed on the surfaces of R-GO sheets. The R-GO/SF/PANI nanocomposite exhibited the best absorption property with the optimum matching thickness of 1.5 mm in the frequency of 2-18 GHz. The value of the maximum RL was -45.00 dB at 16.08 GHz with the 5.48-GHz bandwidth. The excellent absorption properties of R-GO/SF/PANI nanocomposites indicated their great potential as microwave-absorbing materials. PMID:26969594

  19. Characterization of in Vitro Pharmacokinetic Properties of Hoodigogenin A from Hoodia gordonii

    Science.gov (United States)

    This study was aimed to determine ADME properties of Hoodigogenin A, which is aglycone of oxypregnane steroidal glycoside P57AS3 (P57) isolated from Hoodia gordonii. A series of in vitro assays were used to predict its gastric, intestinal and metabolic stability, intestinal and blood brain barrier (...

  20. Characterization of thickness dependent optical properties of zinc phthalocyanine thin film

    Czech Academy of Sciences Publication Activity Database

    Marešová, Eva; Bulíř, Jiří; Lančok, Ján; Pokorný, Petr; Novotný, Michal; Fekete, Ladislav; Fitl, Přemysl; Vrňata, M.

    Lille: European Materials Research Society, 2014 - (Lippert, T.). DD-16-DD-16 [E- MRS 2014 Spring Meeting. 26.05.2014-30.05.2014, Lille] R&D Projects: GA ČR(CZ) GAP108/11/1298 Institutional support: RVO:68378271 Keywords : zinc phthalocyanine * organic thin layers * optical properties Subject RIV: BM - Solid Matter Physics ; Magnetism

  1. Synthesis, Characterization, and Microwave Absorption Properties of Reduced Graphene Oxide/Strontium Ferrite/Polyaniline Nanocomposites

    Science.gov (United States)

    Luo, Juhua; Shen, Pan; Yao, Wei; Jiang, Cuifeng; Xu, Jianguang

    2016-03-01

    Strontium ferrite nanoparticles were prepared by a coprecipitation method, and reduced graphene oxide/strontium ferrite/polyaniline (R-GO/SF/PANI) ternary nanocomposites were prepared by in situ polymerization method. The morphology, structure, and magnetic properties of the ternary nanocomposites were investigated by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), TEM, Raman, and VSM. The microwave-absorbing properties of the composites were measured by a vector network analyzer. The XRD patterns show the single phase of strontium hexaferrite without other intermediate phases. TEM photographs reveal that strontium ferrite nanoparticles are uniformly dispersed on the surfaces of R-GO sheets. The R-GO/SF/PANI nanocomposite exhibited the best absorption property with the optimum matching thickness of 1.5 mm in the frequency of 2-18 GHz. The value of the maximum RL was -45.00 dB at 16.08 GHz with the 5.48-GHz bandwidth. The excellent absorption properties of R-GO/SF/PANI nanocomposites indicated their great potential as microwave-absorbing materials.

  2. Synthesis, characterization, and catalytic properties of stable mesoporous molecular sieve MCM-41 prepared from zeolite mordenite

    International Nuclear Information System (INIS)

    Mesoporous molecular sieves (denoted as M-MCM-41) with ordered hexagonal structure have been successfully synthesized from the assembly of precursors from preformed zeolite Mordenite with CTAB surfactant micelle in alkaline media. The samples were characterized by XRD, N2 adsorption, IR and DTG. The materials exhibit highly hydrothermal stability, as compared with conventional MCM-41. Characterization results indicate that the mesoporous walls of M-MCM-41 contain the secondary building units similar to those in microporous crystal of zeolite Mordenite. In catalytic dealkylation of C10+ aromatic hydrocarbon, M-MCM-41 shows higher activities in comparison with Mordenite and MCM-41, which would be ascribed to the combination of advantages of both MCM-41 (large pores) and Mordenite (strong acidity). Furthermore, this synthesis strategy could be used as a new general method for the preparation of hydrothermally stable mesoporous aluminosilicate materials under alkaline conditions

  3. Synthesis, Characterization, Topographical Modification, and Surface Properties of Copoly(Imide Siloxane)s

    Science.gov (United States)

    Wohl, Christopher J.; Atkins, Brad M.; Belcher, Marcus A.; Connell, John W.

    2012-01-01

    Novel copoly(imide siloxane)s were synthesized from commercially available aminopropyl terminated siloxane oligomers, aromatic dianhydrides, and diamines. This synthetic approach produced copolymers with well-defined siloxane blocks linked with imide units in a random fashion. The copoly(amide acid)s were characterized by solution viscosity and subsequently used to cast thin films followed by thermal imidization in an inert atmosphere. Thin films were characterized using contact angle goniometry, attenuated total reflection Fourier transform infrared spectroscopy, confocal and optical microscopy, and tensile testing. Adhesion of micronsized particles was determined quantitatively using a sonication device. The polydimethylsiloxane (PDMS) moieties lowered the copolymer surface energy due to migration of siloxane moieties to the film s surface, resulting in a notable reduction in particle adhesion. A further reduction in particle adhesion was achieved by introducing topographical features on a scale of several to tens of microns by a laser ablation technique.

  4. Synthesis and Characterization of Imide Containing Hybrid Epoxy Resin with Improved Mechanical and Thermal Properties

    OpenAIRE

    Rane, U. G.; Sabnis, A. A.; Shertukde, V. V.

    2014-01-01

    Phosphorous containing amine, tripropyldiamine phosphine oxide (TPDAP), and hybrid monomer 4-(N-phthalimidophenyl) glycidylether (PPGE) were synthesized and characterized by Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and elemental analysis (EDX). PPGE was incorporated in bisphenol A epoxy resin (BPA) in various concentrations (5% to 20%), based on a weight percentage of BPA resin. Curing was carried out with the stoichiometric amount of TPDA...

  5. Preparation, Characterization, and Photocatalytic Property of C u O - T i O Nanocomposites

    OpenAIRE

    Li, Longfeng; Zhang, Maolin

    2012-01-01

    The Cu2O-TiO2 nanocomposites were successfully synthesized by the homogeneous hydrolysation, followed by the solvothermal crystallization and ethylene glycol-thermal reduction process, respectively. The obtained products were characterized by means of X-ray diffraction(XRD), Uv-vis diffuse reflectance spectroscopy, laser particle size analysis, and scanning electron microscopy (SEM), respectively. The photocatalytic performance of Cu2O-TiO2 nanocomposites was evaluated by the degradation of m...

  6. Preparation, Characterization, and Photocatalytic Property of CuO-TiO Nanocomposites

    OpenAIRE

    Longfeng Li; Maolin Zhang

    2012-01-01

    The Cu2O-TiO2 nanocomposites were successfully synthesized by the homogeneous hydrolysation, followed by the solvothermal crystallization and ethylene glycol-thermal reduction process, respectively. The obtained products were characterized by means of X-ray diffraction(XRD), Uv-vis diffuse reflectance spectroscopy, laser particle size analysis, and scanning electron microscopy (SEM), respectively. The photocatalytic performance of Cu2O-TiO2 nanocomposites was evaluated by the degrad...

  7. Solid state electrochemical characterization of thermodynamic properties of sodium-metal-oxygen systems

    OpenAIRE

    Amin, Md Ruhul

    2005-01-01

    Sodium-metal-oxygen systems (Na-Me-O) being potential electrode materials for potentiometric solid state galvanic cells having very low sodium activities, are usually characterized electrochemically. In this technique the thermodynamic stability data might be erroneous due to the electronic transference through the solid electrolyte especially sodium ion conductors, if the cell is operated under extreme conditions and coexistence of phase mixture can not be checked in situ. In order to solve...

  8. SYNTHESIS, CHARACTERIZATION AND CHELATING PROPERTIES OF PYRIMIDINE-QUINOLINE COMBINED MOLECULE WITH TRANSITION METALS

    Directory of Open Access Journals (Sweden)

    Purvesh J. Shah

    2013-09-01

    Full Text Available The treatment of ethyl-6-methyl-2-oxo-4-phenyl-1,2-dihydropyrimidone-5-carboxylate with 5-amino-8-hydroxyquinoline afford a N-(4-hydroxyquinolin-5-yl-6-methyl-2-oxo-4-phenyl-1,2-dihydro pyrimidine-5-carboxamide(PDHQ. The transition metal complexes of Cu2+,Co2+ ,Ni2+, Mn2+ and Zn2+ of PDHQ have been prepared and characterized by elemental analysis, spectral studies, magnetic moment determination, molar conductivity measurement and microbicidal activity.

  9. Characterization of phenolic compounds and antioxidant properties of Glycyrrhiza glabra L. rhizomes and roots

    OpenAIRE

    Martins, Natália; Barros, Lillian; Dueñas, Montserrat; Santos-Buelga, Celestino; Ferreira, Isabel C.F.R.

    2015-01-01

    The present work aims to characterize and quantify the phenolic composition and to evaluate the antioxidant activity of Glycyrrhiza glabra L. (commonly known as licorice) rhizomes and roots. The antioxidant potential of its methanol/water extract could be related with flavones (mainly apigenin derivatives), flavanones (mainly liquirintin derivatives), a methylated isoflavone and a chalcone, identified in the extract. Lipid peroxidation inhibition was the most pronounced antioxidant effect (EC...

  10. Characterizations of gamma-AG^{**}-groupoids by the properties their gamma-ideals

    OpenAIRE

    Khan, Madad; Ahmad, Naveed; Rehman, Inayatur

    2010-01-01

    In this paper we have discusses {\\Gamma}-left, {\\Gamma}-right, {\\Gamma}-bi-, {\\Gamma}-quasi-, {\\Gamma}-interior and {\\Gamma}-ideals in {\\Gamma}-AG^{**}-groupoids and regular {\\Gamma}-AG^{**}-groupoids. Moreover we have proved that the set of {\\Gamma}-ideals in a regular {\\Gamma}-AG^{**}-groupoid form a semilattice structure. Also we have characterized a regular {\\Gamma}-AG^{**}-groupoid in terms of left ideals.

  11. Characterization and Emulsification Properties of Rhamnolipid and Sophorolipid Biosurfactants and Their Applications

    OpenAIRE

    Nguyen, Thu T.; Sabatini, David A.

    2011-01-01

    Due to their non-toxic nature, biodegradability and production from renewable resources, research has shown an increasing interest in the use of biosurfactants in a wide variety of applications. This paper reviews the characterization of rhamnolipid and sophorolipid biosurfactants based on their hydrophilicity/hydrophobicity and their ability to form microemulsions with a range of oils without additives. The use of the biosurfactants in applications such as detergency and vegetable oil extrac...

  12. Airborne in situ characterization of dry aerosol optical properties in a multisource influenced marine region

    OpenAIRE

    Targino, Admir C.; Noone, Kevin J.; Öström, Elisabeth

    2011-01-01

    In situ data from the 2nd Aerosol Characterization Experiment (ACE-2) were used to describe the aerosol opticalproperties in a marine environment perturbed by continental sources, such as the outflow of European aerosol and dustoutbreaks from North Africa. The data consist of airborne measurements made with an integrating nephelometer andabsorption photometer.The cases investigated in theACE-2 experiment included vertical profiles flown in dusty, polluted and clean airmasses.While it was poss...

  13. Preparation and Characterization of UV-Curable Cyclohexanone-Formaldehyde Resin and Its Cured Film Properties

    OpenAIRE

    2014-01-01

    UV-curable cyclohexanone-formaldehyde (UVCF) resin was prepared with cyclohexanone-formaldehyde (CF) resin, isophorone diisocyanate (IPDI), and pentaerythritol triacrylate (PETA) as base substance, bridging agent, and functional monomer, respectively. The structure of UVCF was characterized by Fourier transform infrared spectroscopy (FT-IR), 1H-nuclear magnetic resonance spectroscopy (1H-NMR), and gel permeation chromatography (GPC). The viscosity and photopolymerization behavior of the UV-cu...

  14. Adsorption properties and advanced textural characterization of novel micro/mesoporous zeolites

    Czech Academy of Sciences Publication Activity Database

    Rathouský, Jiří; Thommes, M.

    Amsterdam : Elsevier B.V./Ltd, 2007 - (Xu, R.; Gao, Z.; Chen, J.; Yan, W.), s. 1042-1047 ISBN 978-0-444-53068-4. - (Studies in surface science and catalysis. Vol. 170) R&D Projects: GA MŠk 1M0577 Institutional research plan: CEZ:AV0Z40400503 Keywords : micro/mesoporous zeolites * adsorption * textural characterization Subject RIV: CF - Physical ; Theoretical Chemistry

  15. Synthesis and Characterization of Novel Chiral Ionic Liquids and Investigation of their Enantiomeric Recognition Properties

    OpenAIRE

    Bwambok, David K.; Hadi M Marwani; Fernand, Vivian E.; FAKAYODE, SAYO O.; Lowry, Mark; Negulescu, Ioan; Robert M Strongin; Warner, Isiah M.

    2008-01-01

    We report the synthesis and characterization of amino acid ester based chiral ionic liquids, derived from L- and D-alanine tert butyl ester chloride. The synthesis was accomplished via an anion metathesis reaction between commercially available L-and D-alanine tert butyl ester chloride using a variety of counterions such as lithium bis (trifluoromethane) sulfonimide, silver nitrate, silver lactate, and silver tetrafluoroborate. Both enantiomeric forms were obtained as confirmed by bands of op...

  16. Reactor modeling and physicochemical properties characterization for a polyethylene fluidized bed reactor

    OpenAIRE

    F. A. N. Fernandes; L. M. F. LONA BATISTA

    1999-01-01

    A new steady state model for the fluidized bed reactor and a physicochemical characterization model were developed for the simulation of polyethylene production using gas-phase technology. The association of these models was done in order to predict the characteristics of the polymer produced in the fluidized bed reactor (molecular weight, polydispersity, melt index, and other characteristics) throughout the reactor and also to predict the growth of the polymer particle.

  17. Reactor modeling and physicochemical properties characterization for a polyethylene fluidized bed reactor

    Directory of Open Access Journals (Sweden)

    FERNANDES F. A. N.

    1999-01-01

    Full Text Available A new steady state model for the fluidized bed reactor and a physicochemical characterization model were developed for the simulation of polyethylene production using gas-phase technology. The association of these models was done in order to predict the characteristics of the polymer produced in the fluidized bed reactor (molecular weight, polydispersity, melt index, and other characteristics throughout the reactor and also to predict the growth of the polymer particle.

  18. Production, characterization, and mechanical properties of starch modified by Ophiostoma spp.

    OpenAIRE

    Saville, B. A.; Sain, M.; Jeng, R.; Huang, C. B.; Hubbes, M.

    2006-01-01

    Microbial modification of starch with Ophiostoma spp. was investigated, with the purpose of developing a novel packaging material for the food or pharmaceutical industries. Various starch sources, such as tapioca, potato, corn, rice and amylopectin were tested as raw materials. The initial screening demonstrated that tapioca and potato starch had better performance for biopolymer production. The yield was about 85%. Preliminary characterization of the modified biopolymer was also conducted. F...

  19. Synthesis, Characterization and Chelating Properties of Benzimidazole-Salicylic Acid Combined Molecule

    OpenAIRE

    Kamlesh V. Patel; Singh, Arun

    2009-01-01

    Aminomethylation (i.e. Mannich reaction) of benzimidazole was carried out by treating benzimidalzole with formaldehyde and 4-aminosalicylic acid. The resultant compound was designated as 1-(4-carboxy-3-hydroxyphenyl aminomethyl) benzimidazole (BI-SA). The transition metal complexes of Cu2+, Co2+, Ni2+, Mn2+, Zn2+ and Fe3+ of BI-SA have been prepared and characterized by elemental analyses, spectral studies, magnetic moment determination, molar conductivity measurement and microbicidal activity.

  20. Microstructural characterization of the chemomechanical behavior of asphalt in terms of aging and fatigue performance properties

    Science.gov (United States)

    Allen, Robert Grover

    The study of asphalt chemo-mechanics requires a basic understanding of the physical properties and chemical composition of asphalt and how these properties are linked to changes in performance induced by chemical modifications. This work uniquely implements the framework of chemo-mechanics by investigating two types of chemical modification processes, natural (oxidative aging) and synthetic (chemical doping) as they relate not only to macro-scale properties of asphalt binder but also to the asphalt microstructure and nanorheology. Furthermore, this study demonstrates the application of atomic force microscopy (AFM) imaging and the extraction of nano-scale engineering properties, i.e. elastic modulus, relaxation modulus, and surface energy, as a method to predict performance related to the fatigue characteristics of asphalt binders by modeling intrinsic material flaws present amongst phase interfaces. It was revealed that oxidative aging induces substantial microstructural changes in asphalt, including variations in phase structure, phase properties, and phase distribution. It has also been shown that certain asphalt chemical parameters have a consistent and measureable effect on the asphalt microstructure that is observed with AFM. In fact, particular phases that emerged via chemical doping revealed a surprising correlation between oxidative aging and the saturates chemical parameter of asphalt in terms of how they explicitly impact durability and performance of asphalt. By implementing a crack initiation model---which requires measureable microstructural characteristics as an input parameter---it was found that microstructural flaws (depending on the extremity) can have a more profound impact on asphalt performance than the properties of the material located between the flaws. It was also discovered by comparing the findings to performance data in the Strategic Highway Research Program's (SHRP's) Materials Reference Library (MRL), that the crack initiation model

  1. Characterization of the Microstructure, Fracture, and Mechanical Properties of Aluminum Alloys 7085-O and 7175-T7452 Hollow Cylinder Extrusions

    Science.gov (United States)

    Benoit, Samuel G.; Chalivendra, Vijaya B.; Rice, Matthew A.; Doleski, Robert F.

    2016-06-01

    Microstructural, tensile, and fracture characterizations of cylindrically forged forms of aluminum alloys AA7085-O and AA7175-T7452 were performed. Mechanical and fracture properties were investigated along radial, circumferential, and longitudinal directions to determine directional dependency. American Society for Testing and Materials (ASTM) test methods (ASTM E8-04 and ASTM E1820) were employed for both the tensile and fracture characterizations, respectively. The tensile and fracture properties were related to microstructure in each direction. The strength, elongation at break, and ultimate tensile strength of AA7085-O were higher than those of AA7175-T7452. AA7175-T7452 alloy failed in a brittle manner during fracture studies. AA7085-O outperformed AA7175-T7452 on fracture energy in all of the orientations studied. Smaller grain sizes on the planes normal to circumferential and longitudinal directions showed improvement in both elongation at break and fracture energy values compared to those of radial direction. Scanning electron microscopy images demonstrated cleavage fracture in AA7175-T7452 and transgranular fracture in AA7085-O.

  2. High color purity orange-emitting KBaBP2O8:Eu3+ phosphor: Synthesis, characterization and photoluminescence properties

    International Nuclear Information System (INIS)

    A series of orange-emitting KBaBP2O8:Eu3+ phosphors with high color purity were synthesized by using a solid-state reaction technique at high-temperature. The phase purity, surface morphology, compositional and elemental analysis as well as photoluminescence properties were investigated by various characterization methods including X-ray diffraction (XRD), scanning electron microscopic (SEM), energy dispersive X-ray spectra (EDS), Fourier transform infrared (FT-IR), and fluorescence spectroscopy (FS) measurements. The luminescence characteristics including excitation and emission spectrum, decay curves, chromaticity coordinates and color purity were discussed and calculated. The influence of the doping concentration of Eu3+ and charge compensator (alkali metal ion) on the relative emission intensity of Eu3+ was investigated. The as-prepared phosphor can be effectively excited with a 394 nm light, and exhibit orange emission with high color purity belonging to the prevailing 5D0→7F1 magnetic dipole transition (594 nm) of Eu3+. The above work indicates this phosphor could be a potential candidate as orange phosphor for application in white light-emitting diodes (w-LEDs). - Highlights: • A series of KBaBP2O8:Eu3+ phosphors were prepared by a solid-state reaction. • Its structure, luminescent properties are well characterized and studied. • The concentration quenching mechanism of Eu3+ was determined. • KBaBP2O8:Eu3+ shows orange emissions under UV excitation

  3. Characterization of the anomalous luminescence properties from self-ordered porous anodic alumina with oxalic acid electrolytes

    International Nuclear Information System (INIS)

    The pore height and diameter of the nanoscale structure of porous anodic alumina (PAA) film produced by the anodization technique are controllable. The structures can be applied for the fabrication of visible spectral range optical devices. In this study we characterized the luminescence properties of self-ordered PAA films evaporated onto silicon substrates. Anomalous luminescence properties produced by carrier confinement were observed in PAA films fabricated with the introduction of oxalic acid electrolytes during the anodization process. The recombination mechanisms were characterized by measuring the temperature-dependent photoluminescence (PL) spectra. The PL spectra of PAA films show an asymmetrical luminescence profile in the blue emission region. The Gaussian function divides these into two subbands. The subbands originate from two different kinds of oxygen-deficient defect centers, namely, F+ (oxygen vacancy with only one electron) and F (oxygen vacancy with two electrons) centers. The F centers are densest at the surface but show a gradual decrease with an increase in the pore wall depth and electrolyte concentration. However, the reverse trend is observed for the F+ centers. In strong contrast to the commonly expected trend of a uniform reduction in non-radiative recombination with decreasing lattice temperature, we observed an anomalous low-temperature PL growth and decline between the F and F+ centers. Theoretical models corroborate the anomalous temperature behavior. All the calculations are in agreement with the experimental observations.

  4. Purification of cress seed (Lepidium sativum) gum: Physicochemical characterization and functional properties

    DEFF Research Database (Denmark)

    Razmkhah, Somayeh; Mohammadifar, Mohammad Amin; Razavi, Seyed Mohammad Ali;

    2016-01-01

    purification methods reduced ash and protein content and molecular weight of cress seed gum. The main decomposition of the purified samples started above 200º C and initial decomposition temperature of the crude gum was 190.21º C. DSC thermograms of the purified gums showed two exothermic events at 257......The aim of the present study was to investigate the effects of different purification methods (ethanol, isopropanol and ethanol-isopropanol) on the physicochemical and functional characteristics of cress seed gum. Sugar composition and molecular weight of the samples varied significantly. All the...... emulsifying properties of cress seed gum and there was no significant difference among the purified samples. Crude gum showed the lowest foaming properties, while samples I and E (purified using ethanol) showed the highest foaming capacity and foam stability, respectively. (C) 2015 Elsevier Ltd. All rights...

  5. Hydrothermal synthesis, characterization and luminescent properties of lanthanide-doped NaLaF$_4$ nanoparticles

    Indian Academy of Sciences (India)

    JIGMET LADOL; HEENA KHAJURIA; SONIKA KHAJURIA; HAQ NAWAZ SHEIKH

    2016-08-01

    Nanoparticles of sodium lanthanum (III) fluoride-doped and co-doped with Eu$^{3+}/Tb$^{3+}$ were prepared by the hydrothermal method using citric acid as structure-directing agent. Structural aspects and optical properties of synthesized nanoparticles were studied by powder X-ray diffraction (XRPD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), energy-dispersive X-ray spectra (EDS), particle size by dynamic light scattering (DLS), Fourier transform infrared (FTIR) spectrum and photoluminescence (PL) techniques. Nanoparticles consist of well-crystallized hexagonal phase and the average crystallite size for undoped and doped-NaLaF$_4$ nanoparticles are in the range of 20–22 nm. TEM images show that nanoparticles have cylindrical shape and crystalline nature of nanoparticles was confirmed by SAED patterns. Downconversion(DC) luminescent properties of doped NaLaF4 were also investigated and impact of co-doping has been explored.

  6. Characterization of the mechanical properties of tough biopolymer fibres from the mussel byssus of Aulacomya ater.

    Science.gov (United States)

    Troncoso, O P; Torres, F G; Grande, C J

    2008-07-01

    Byssus fibres are tough biopolymer fibres produced by mussels to attach themselves to rocks. In this communication, we present the mechanical properties of the byssus from the South American mussel Aulacomya ater which have not been previously reported in the literature. The mechanical properties of the whole threads were assessed by uniaxial tensile tests of dry and hydrated specimens. Elastoplastic and elastomeric stress-strain curves were found for byssal threads from A. ater in the dry and hydrated state, respectively. The results obtained from mechanical tests were modelled using linear, power-law-type and Mooney-Rivlin relationships. These methods for dealing with tensile measurements of mussel byssus have the potential to be used with other stretchy biomaterials. PMID:18321800

  7. Maillard Reaction in Natural Rubber Latex: Characterization and Physical Properties of Solid Natural Rubber

    Directory of Open Access Journals (Sweden)

    S. Montha

    2016-01-01

    Full Text Available Maillard reaction in Natural Rubber (NR latex was investigated by treating fresh NR latex with glutaraldehyde (C5H8O2 in amounts of 0, 50, 100, and 200 mmol/kg of latex. Protein cross-linking in fresh NR latex and solid NR was confirmed by using sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE and attenuated total reflection infrared (ATR-IR spectroscopy, respectively. It was found that degree of protein cross-linking in NR increased with increasing C5H8O2 concentration. Physical properties of untreated and treated NR substances in terms of gel content, initial Wallace plasticity (P0, plasticity retention index (PRI, Mooney viscosity, and tensile strength were carefully explored. Results clearly showed that the Maillard cross-linking of proteins had remarkable effect on bulk NR properties, that is, solvent resistance, hardness, resistance to oxidation, rheological behavior, and resistance to stretching out.

  8. Structure and Properties Characterization of Ceramic Coatings Produced on Steel Using a Combined Technique

    Institute of Scientific and Technical Information of China (English)

    SHENDe-jiu; WANGYu-lin; GUWei-chao; XINGGuang-zhong

    2004-01-01

    Metallurgically bonded ceramic coatings were prepared on a steel surface with a combined method of arc spraying and micro-arc oxidation for the first time. Coatings were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Point and line distribution of elements of the ceramic coatings were determined using energy dispersive spectroscopy (EDS). Coatings abrasive wear resistance, corrosion resistance and hot impact property were assessed respectively. The property test results show that metallurgically bonded ceramic coatings were formed on aluminum coatings and the ceramic coatings is mainly composed of α-Al2O3, γ-Al2O3, θ-Al2O3 and a little amorphous. The coatings possess excellent abrasive wear, corrosion and hot shock resistance, which can in part be attributed to the gradual distribution of different phases from surface to the substrate.

  9. Characterization of the properties of thermoplastic elastomers containing waste rubber tire powder

    International Nuclear Information System (INIS)

    The aim of this research was to recycle waste rubber tires by using powdering technology and treating the waste rubber tire powder with bitumen. It has been proven that the elongation at break, thermal stability and processing flowability of composites of polypropylene (PP), waste rubber tire powder (WRT) and bitumen composites are better than those of PP/WRT composite. A comparative study has been made to evaluate the influence of bitumen content and different compatibilizers on the properties of PP/WRT/bitumen composites, using a universal testing machine (UTM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and a capillary rheometer. The results suggested that the properties of PP/WRT/bitumen composites were dependent on the bitumen content and the kind of compatibilizer used

  10. Structures and Properties Characterization of Acrylonitrile-butadiene-styrene/Organo-palygorskite Clay Composites

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhe; CHANG Ying; XU Jian; WU Zhancui; MA Hengchang; LEI Ziqiang

    2012-01-01

    Palygorskite (PGS) and vinyl tris-(2-methoxyethoxy) silane (KH-172) modified palygorskite (OPGS) were used to prepare acrylonitrile-butadiene-styrene (ABS)/clay composites.Thermal stability of the composites was evaluated by using thermogravimetric analysis (TGA).The morphology of the fractured surface and the degree of dispersion of the clay in the ABS matrix were observed by scanning electron microscopy (SEM).X-ray diffraction (XRD) analysis results showed the variation of the crystal structure.Measurements of the tensile properties of the ABS/clay composites proved that the ABS/OPGS composited material represented the most excellent tensile property,because of good compatibility and dispersion of ABS with OPGS.

  11. Structure and Properties Characterization of Ceramic Coatings Produced on Steel Using a Combined Technique

    Institute of Scientific and Technical Information of China (English)

    SHEN De-jiu; WANG Yu-lin; GU Wei-chao; XING Guang-zhong

    2004-01-01

    Metallurgically bonded ceramic coatings were prepared on a steel surface with a combined method of arc spraying and micro-arc oxidation for the first time. Coatings were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Point and line distribution of elements of the ceramic coatings were determined using energy dispersive spectroscopy (EDS). Coatings abrasive wear resistance, corrosion resistance and hot impact property were assessed respectively. The property test results show that metallurgically bonded ceramic coatings were formed on aluminum coatings and the ceramic coatings is mainly composed of α-Al2O3、γ-Al2O3、θ-Al2O3 and a little amorphous. The coatings possess excellent abrasive wear, corrosion and hot shock resistance, which can in part be attributed to the gradual distribution of different phases from surface to the substrate.

  12. Optimization and characterization of adhesion properties of DLC coatings on different substrates

    International Nuclear Information System (INIS)

    The Diamond Like Carbon coatings (DLC) are gaining prime importance in the field of surface engineering especially cutting tools technology. The self lubricating property of these coatings makes them unique among other coatings like TiN, TiAlN, CrN etc. Unlike other coatings, DLC coatings give better surface finish and their self lubrication reduces the wear of a part to large extent. In present work, different substrates were selected to study the wear and adhesion behavior of DLC coatings. The coating was produced by physical Vapor Deposition (PVD) technique and the adhesive properties of DLC coatings were analyzed under ambient conditions using nano Scratch testing. Scanning electron microscope (SEM) was used to observe the scratches and their mechanisms. (author)

  13. Optimization and characterization of adhesion properties of DLC coatings on different substrates

    International Nuclear Information System (INIS)

    The Diamond Like Carbon coatings (DLC) are gaining prime importance in the field of surface engineering especially cutting tools technology. The self lubricating property of these coatings makes them unique among other coatings like TiN, TiAlN, CrN etc. Unlike other coatings, DLC coatings give better surface finish and their self lubrication reduces the wear of a part to large extent. In present work, different substrates were selected to study the wear and adhesion behavior of DLC coatings. The coating was produced by physical Vapor Deposition (PVD) technique and the adhesive properties of DLC coatings were analyzed under ambient conditions using nano Scratch testing. Scanning electron microscope (SEM) was used to observe the scratches and their mechanisms

  14. Development of a dielectric ceramic based on diatomite-titania part two: dielectric properties characterization

    OpenAIRE

    Medeiros Jamilson Pinto; Tavares Elcio Correia de Souza; Gomes Uilame Umbelino; Acchar Wilson

    1998-01-01

    Dielectric properties of sintered diatomite-titania ceramics are presented. Specific capacitance, dissipation factor, quality factor and dielectric constant were determined as a function of sintering temperature, titania content and frequency; the temperature coefficient of capacitance was measured as a function of frequency. Besides leakage current, the dependence of the insulation resistance and the dielectric strength on the applied dc voltage were studied. The results show that diatomite-...

  15. Characterization and biological properties of Citrus industrial derivatives and waste products for the formulation of nutraceuticals

    OpenAIRE

    Pagano, Francesco

    2015-01-01

    2013 - 2014 Polyphenols are natural chemical compounds, common in higher plants as and particularly known and appreciated for their health properties. We focused attention on Citrus bergamia, Citrus sinensis, Mela annurca and Vitis Vinifera. Citrus is one of larges species among plant; it consists of 40 species which are distributed in all continents and its fruits. We have developed a fast HPLC with ion-trap TOF-MS method for the analysis of flavonoids in these juices. With respect to the...

  16. Characterization of fracture properties of thin aluminum inclusions embedded in anisotropic laminate composites

    OpenAIRE

    Gabriella Bolzon; Vladimir Buljak; Emanuele Zappa

    2012-01-01

    The fracture properties of thin aluminum inclusions embedded in anisotropic paperboard composites, of interest for food and beverage packaging industry, can be determined by performing tensile tests on non-conventional heterogeneous specimens. The region of interest of the investigated material samples is monitored all along the experiment by digital image correlation techniques, which allow to recover qualitative and quantitative information about the metal deformation and about the evoluti...

  17. Radiation effect on characterization and physical properties of polymer nano composites

    International Nuclear Information System (INIS)

    Polymeric materials are of interest in scientific and technological research, because they can be tailored to meet specific requirement for a verity of applications, this is mainly due to their light weight, good mechanical strength, and optical properties.From which, Poly Vinyl Alcohol (PVA) is one of the most important polymeric materials, because it has many applications in industry and is of relatively low cost in manufacture. It is well documented that electrical and optical properties of polymers can be improved to a desired limit through suitable doping. In this concern, and since Ag+ is a fast conducting ion in a number of crystalline and amorphous materials, its incorporation within a polymeric system may be expected to enhance its electrical and optical properties. In the present study the PVA/Ag nano composite with different contents of inorganic phase of (2, 3, 4, 5, 6, 7, and 8) wt % were prepared by reduction of Ag+ ions in PVA solution using gamma irradiation with different dose of (15, 25, 50, 75, 100) kGy. The Ag particle size was found to be around 14.0 nm based on the UV-Vis spectroscopy and Dynamic Light Scattering (DLS) measurements. Also, the structural studies of the synthesized PVA/Ag nano composites have been carried out through FTIR, and XRD studies. Further, the dependence of the optical and electrical properties of PVA on the concentration of the embedded nano-Ag was reported. As well, the effects of γ- irradiation have been studied applying UV-Vis spectroscopy and electrical characteristics measurements, respectively.

  18. Characterization and cartography of topsoil hydraulic properties in a French mountainous peri-urban catchment

    OpenAIRE

    Gonzalez-Sosa, E.; Braud, I.; J. Dehotin; Branger, F.; Lagouy, M.

    2009-01-01

    International audience Due to the increase of urbanization and modification of agricultural practices, peri-urban areas experiment a quick change in land use. The impact of such change on the catchment hydrological cycle must be quantified. To achieve this goal, distributed hydrological models offer the ability to take into account land use change, and more specifically its effect on surface infiltration capacity. A distributed assessment of infiltration properties and their variability at...

  19. Preparation, Characterization, and Enhanced Thermal and Mechanical Properties of Epoxy-Titania Composites

    OpenAIRE

    Zakya Rubab; Adeel Afzal; Siddiqi, Humaira M.; Shaukat Saeed

    2014-01-01

    This paper presents the synthesis and thermal and mechanical properties of epoxy-titania composites. First, submicron titania particles are prepared via surfactant-free sol-gel method using TiCl4 as precursor. These particles are subsequently used as inorganic fillers (or reinforcement) for thermally cured epoxy polymers. Epoxy-titania composites are prepared via mechanical mixing of titania particles with liquid epoxy resin and subsequently curing the mixture with an aliphatic diamine. The a...

  20. Characterizing the shape and material properties of hidden targets from magnetic induction data

    OpenAIRE

    Paul D Ledger, William R.B. Lionheart

    2015-01-01

    The aim of this paper is to show that, for the eddy current model, the leading order term for the perturbation in the magnetic field, due to the presence of a small conducting magnetic inclusion, can be expressed in terms of a symmetric rank 2 polarization tensor. This tensor contains information about the shape and material properties of the object and is independent of position. We apply a recently derived asymptotic formula for the perturbed magnetic field, due to the presence ...