WorldWideScience

Sample records for chemical preparation

  1. PROBIOTIC CLEANING PREPARATIONS VERSUS CHEMICAL DISINFECTANTS

    Directory of Open Access Journals (Sweden)

    W. Luepcke

    2017-12-01

    Full Text Available Probiotic detergents are increasingly used and are a real alternative for limiting the use of chemical cleaners, chemical disinfectants and antibiotics. They therefore have a great future because they contribute to animal health, to the hygienic production of food products of animal origin and to their harmlessness and to consumer health and environmental protection where they even have a beneficial effect on the microflora apart from chemical disinfectants that have a negative impact and destroy the beneficial microflora.

  2. [Responsibilities of enterprises introducing new dangerous chemical substances and preparations].

    Science.gov (United States)

    Cieśla, Jacek; Majka, Jerzy

    2004-01-01

    The paper reviews the responsibilities of producers, importers and distributors set in a new Act of January 2001 on chemical substances and preparations (Off. J. 2001, No. 11, item 84, with subsequent amendments). This Act together with executive provisions is aimed at harmonizing Polish legislation with EU requirements. The Act sets conditions, restriction and bans of production placing on the market and use of chemical substances and preparations in order to protect human health and environment against their harmful effects. The Act together with a number of executive provisions render those who introduce dangerous chemicals and chemical preparations, including distributors responsible for: classification and labelling of dangerous chemical substances and preparations; possessing, making available and up-dating safety data sheets; supplying packages containing certain dangerous substances with child-proof fastenings; notifying the Inspector for Chemical Substances and Preparations about placing a dangerous preparation on the market; notifying the Inspector about a new substance and conducting required studies; being properly qualified to handle dangerous substances. The Act strictly defines the term "placing a substance or a preparation on the market"--it means making a substance or a preparation available to third parties on the territory of The Republic of Poland, territories of the Member States of the European Union or the territory of Iceland, Liechtenstein and Norway, unless the Act provides otherwise; it also means introduction of a substance or a preparation from outside of the territory referred to above on the customs territory of The Republic of Poland, or that of the member states of the European Union and other states listed above. In addition, some of the responsibilities defined by the provisions of the law on chemical substances and preparations are also applicable to handling of biocidals, which are classified as dangerous substances. The Act

  3. Physical, sensory and chemical properties of bread prepared from ...

    African Journals Online (AJOL)

    Physical, sensory and chemical properties of bread prepared from wheat and ... Different levels (0, 1, 2 and 3% w/w) of cissus gum powder was added to ... flours for bread making where 100% wheat bread without cissus gum served as control. ... serve as a gluten substitute in preparing acceptable wheat bread substituted ...

  4. Chemical Preparation Laboratory IND Candidate Compounds.

    Science.gov (United States)

    1986-01-21

    and final products unreported in the chemical literature were fully characterized by elemental and spectral analyses. 3 V% TABLE OF CONTENTS Page I...resulting crystalline material was filtered and washed with water to yield 2.0 g. An additional 0.2 g of the product was recovered from the above filtrate... mercaptopurine (Tri-C- acetvlthioinosine) (3): To a well stirred mixture of 2 (93.0 g, 0.236 mol) and pyridine (3570 mL), phosphorus pentasulfide (220.0 g, 0.49

  5. Characteristics of nanosized zirconia prepared by plasma and chemical technique

    International Nuclear Information System (INIS)

    Kuznetsova, L.; Grabis, J.; Heidemane, G.

    2003-01-01

    The studied preparation method of zirconia using the plasma technique, azeotropic distillation and glycine routes ensure obtaining of nano sized powders with close average particle size but different crystallite size and phase composition. The sinterability of nano sized zirconia particles prepared by plasma technique or wet-chemical methods is similar and depends on the green density of pressed powders, improvement of with can be achieved by using of granulated precursors. (authors)

  6. Compaction of Chemically Prepared Amorphous Fe-B nanoparticles

    DEFF Research Database (Denmark)

    Hendriksen, P.V.; Bødker, Franz; Mørup, Steen

    1997-01-01

    We report on attempts to compact chemically prepared amorphous iron-boron particles. The praticles have a size of about 100 nm and are pyrophoric. We have made a special die for uniaxial pressing in which the compaction can be performed at elevated temperature without exposing the powder to air...

  7. Chemical flowsheet conditions for preparing urania spheres by internal gelation

    International Nuclear Information System (INIS)

    Haas, P.A.; Begovich, J.M.; Ryon, A.D.; Vavruska, J.S.

    1979-01-01

    Small, ceramic urania spheres can be prepared for use as nuclear fuel by internal chemical gelation of uranyl nitrate solution droplets. Decomposition of hexamethylenetetramine (HMTA) dissolved in the uranyl nitrate solution releases ammonia to precipitate hydrated UO 3 . Previously established flowsheet conditions have been improved and modified at ORNL and have been applied to prepare dense UO 2 spheres with average diameters of 1200, 300, and 30 μm. Acid-deficient uranyl nitrate (ADUN) solutions up to 3.4 M in uranium with NO 3 - /U mole ratios of 1.5 to 1.7 are prepared by dissolution of U 3 O 8 or UO 3 . Continuous mixing of metered, cooled ADUN containing urea and HMTA solutions provides a smooth, regulated flow of the temperature-sensitive feed solution. The gelation times for solution drops in organic liquids at 45 to 95 0 C depend on both the chemical reaction rates and the rates of heat transfer. The gel properties vary with temperature and other gelation variables. Gelation conditions were determined which allow easy washing, drying, firing, and sintering to produce dense UO 2 spheres of all three sizes. The 1200- and 300-μm UO 2 spheres were pepared by gelation in trichloroethylene at 50 to 65 0 C; 2-ethyl-l-hexanol was used as the gelation medium to prepare 30-μm UO 2 spheres. Washing and drying requirements were determined. The gel dried to 225 0 C contains about 95% UO 3 ; the remaining components are H 2 O, NH 3 - , which are volatilized during firing to UO 2

  8. A roadmap to high quality chemically prepared graphene

    Energy Technology Data Exchange (ETDEWEB)

    Gengler, Regis Y N; Spyrou, Konstantinos; Rudolf, Petra, E-mail: r.gengler@rug.n, E-mail: p.rudolf@rug.n [Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG Groningen (Netherlands)

    2010-09-22

    Graphene was discovered half a decade ago and proved the existence of a two-dimensional system which becomes stable as a result of 3D corrugation. It appeared very quickly that this exceptional material had truly outstanding electronic, mechanical, thermal and optical properties. Consequently a broad range of applications appeared, as the graphene science speedily moved forward. Since then, a lot of effort has been devoted not only to the study of graphene but also to its fabrication. Here we review the chemical approaches to graphene production, their advantages as well as their downsides. Our aim is to draw a roadmap of today's most reliable path to high quality graphene via chemical preparation.

  9. A roadmap to high quality chemically prepared graphene

    International Nuclear Information System (INIS)

    Gengler, Regis Y N; Spyrou, Konstantinos; Rudolf, Petra

    2010-01-01

    Graphene was discovered half a decade ago and proved the existence of a two-dimensional system which becomes stable as a result of 3D corrugation. It appeared very quickly that this exceptional material had truly outstanding electronic, mechanical, thermal and optical properties. Consequently a broad range of applications appeared, as the graphene science speedily moved forward. Since then, a lot of effort has been devoted not only to the study of graphene but also to its fabrication. Here we review the chemical approaches to graphene production, their advantages as well as their downsides. Our aim is to draw a roadmap of today's most reliable path to high quality graphene via chemical preparation.

  10. Radiation chemical route for preparation of metal nanoparticles

    International Nuclear Information System (INIS)

    Kapoor, S.; Mukherjee, T.

    2006-01-01

    Nanoparticles show properties that are neither seen in the bulk or at atomic level. The unusual properties are governed by quantum size effect. Due to this various methodologies have been endeavored to control the size of the particles. In the present work we show the use of two complimentary techniques (radiation and photo) to synthesize and control the size of the metal particles. In-situ synthesis of fine silver, thallium and cadmium particles has been carried out by gamma-irradiation and electron pulse irradiation at room temperature in the pre-organized gel of polyacrylamide or cyclodextrin cavity. The role of generation of nuclei in high concentrations in stabilization of metal nanoparticles in hydrophobic cavity is shown. Similarly the importance of entrapment of metal ions in the polymer matrix during its formation is highlighted. The work is further extended to exploit the microemulsion droplets for stabilization of Cd nanoparticles. Utility of pulse radiolysis in probing the mechanism of the formation of metal nanoparticles is also shown. Ultrafast laser pulses were employed to control the morphology of the pre-prepared Pt nanoparticles. The changes in reduction of shape and size are considered to occur through melting and vaporization of the nanoparticles. Pt nanoparticles were coated on the inner walls of the tubular pyrex reactor and tested for their catalytic activity for oxidation of CO. It was observed that Pt nanoparticles prepared in the presence of a stabilizer (gelatin) showed a higher tendency to adhere to the inner walls of the pyrex reactor as compared to that prepared in the presence of silica nanoparticles. The catalyst was found to be active at ≥150 degree C giving CO 2 . Chemically reduced Pt nanoparticles stabilized on silica nanoparticles gave ∼7% CO conversion per hr. However, radiolytically prepared Pt nanoaprticles stabilized by gelatin gave ∼10% conversion per hr. The data indicates that catalytic oxidation of CO takes place

  11. [Our medicinal preparations in the mid-19th century. Part I--Introduction and chemical preparations].

    Science.gov (United States)

    Drábek, Pavel

    2012-08-01

    The paper deals with the development of the first editions of the Austrian Pharmacopoeia, Pharmacopoea Austriaca, since its origin in the year 1812. It demonstrates its gradual retardation in the period when nearly all medicinal substances had to be prepared only in pharmacies. The conception was changed as late as 1855 in the Fifth Edition, when it was allowed to buy many medicinal substances from producers or wholesalers. At the same time, requirements for organoleptic properties and chemical purity began to be introduced. The present communication also deals with the chemical drugs used in the mid-19th century and is based on a comparison of the pharmacopoeias of 1836 and 1855. It presents some typical examples, such as alkaloids and metal compounds.

  12. Indium tin oxide films prepared via wet chemical route

    International Nuclear Information System (INIS)

    Legnani, C.; Lima, S.A.M.; Oliveira, H.H.S.; Quirino, W.G.; Machado, R.; Santos, R.M.B.; Davolos, M.R.; Achete, C.A.; Cremona, M.

    2007-01-01

    In this work, indium tin oxide (ITO) films were prepared using a wet chemical route, the Pechini method. This consists of a polyesterification reaction between an α-hydroxicarboxylate complex (indium citrate and tin citrate) with a polyalcohol (ethylene glycol) followed by a post annealing at 500 deg. C. A 10 at.% of doping of Sn 4+ ions into an In 2 O 3 matrix was successfully achieved through this method. In order to characterize the structure, the morphology as well as the optical and electrical properties of the produced ITO films, they were analyzed using different experimental techniques. The obtained films are highly transparent, exhibiting transmittance of about 85% at 550 nm. They are crystalline with a preferred orientation of [222]. Microscopy discloses that the films are composed of grains of 30 nm average size and 0.63 nm RMS roughness. The films' measured resistivity, mobility and charge carrier concentration were 5.8 x 10 -3 Ω cm, 2.9 cm 2 /V s and - 3.5 x 10 20 /cm 3 , respectively. While the low mobility value can be related to the small grain size, the charge carrier concentration value can be explained in terms of the high oxygen concentration level resulting from the thermal treatment process performed in air. The experimental conditions are being refined to improve the electrical characteristics of the films while good optical, chemical, structural and morphological qualities already achieved are maintained

  13. Bioactive carbon-PEEK composites prepared by chemical surface treatment.

    Science.gov (United States)

    Miyazaki, Toshiki; Matsunami, Chisato; Shirosaki, Yuki

    2017-01-01

    Polyetheretherketone (PEEK) has attracted much attention as an artificial intervertebral spacer for spinal reconstruction. Furthermore, PEEK plastic reinforced with carbon fiber has twice the bending strength of pure PEEK. However, the PEEK-based materials do not show ability for direct bone bonding, i.e., bioactivity. Although several trials have been conducted for enabling PEEK with bioactivity, few studies have reported on bioactive surface modification of carbon-PEEK composites. In the present study, we attempted the preparation of bioactive carbon-PEEK composites by chemical treatments with H 2 SO 4 and CaCl 2 . Bioactivity was evaluated by in vitro apatite formation in simulated body fluid (SBF). The apatite formation on the carbon-PEEK composite was compared with that of pure PEEK. Both pure PEEK and carbon-PEEK composite formed the apatite in SBF when they were treated with H 2 SO 4 and CaCl 2 ; the latter showed higher apatite-forming ability than the former. It is conjectured that many functional groups able to induce the apatite nucleation, such as sulfo and carboxyl groups, are incorporated into the dispersed carbon phase in the carbon-PEEK composites. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Radiation-chemical preparation of poly(vinyl alcohol) hydrogels

    International Nuclear Information System (INIS)

    Duflot, Anastasia V.; Kitaeva, Natalia K.; Duflot, Vladimir R.

    2015-01-01

    This work reports the usage of method of radiation-chemical synthesis to prepare cross-linked hydrogels from poly(vinyl alcohol) modified with glycidyl methacrylate. Synthesis kinetics of modified poly(vinyl alcohol) and properties of hydrogels were studied. The gel fraction, swelling, mechanical properties, and water content of the hydrogels were measured. It was found that gel fraction increases with increasing radiation dose, concentration of modified poly(vinyl alcohol), and reaches 60%. It was established by differential scanning calorimetry that a fraction of the “bound” water in hydrogels is 50–70% and independent of gel fraction content. In addition to “bound” and “free” states, water in hydrogels is also present in the intermediate state. - Highlights: • The synthesis and the properties of poly(vinyl alcohol) hydrogels were studied. • PVA was modified by glycidyl methacrylate before gamma cross-linking. • The modification results in decreasing of PVA cross-linking dose by 3 orders lower. • The gel fraction and water content of the hydrogels were measured. • A fraction of the “bound” water in hydrogels is independent of gel fraction content

  15. Audit Report. Johnston Atoll Chemical Agent Disposal System Preparation for Year 2000

    National Research Council Canada - National Science Library

    1998-01-01

    .... The overall audit objective was to determine whether the Johnston Atoll Chemical Agent Disposal System was adequately preparing its information technology systems to resolve date-processing issues...

  16. Chemical preparation of graphene-based nanomaterials and their applications in chemical and biological sensors.

    Science.gov (United States)

    Jiang, Hongji

    2011-09-05

    Graphene is a flat monolayer of carbon atoms packed tightly into a 2D honeycomb lattice that shows many intriguing properties meeting the key requirements for the implementation of highly excellent sensors, and all kinds of proof-of-concept sensors have been devised. To realize the potential sensor applications, the key is to synthesize graphene in a controlled way to achieve enhanced solution-processing capabilities, and at the same time to maintain or even improve the intrinsic properties of graphene. Several production techniques for graphene-based nanomaterials have been developed, ranging from the mechanical cleavage and chemical exfoliation of high-quality graphene to direct growth onto different substrates and the chemical routes using graphite oxide as a precusor to the newly developed bottom-up approach at the molecular level. The current review critically explores the recent progress on the chemical preparation of graphene-based nanomaterials and their applications in sensors. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Electrical properties of chemically prepared nonstoichiometric CuIn ...

    Indian Academy of Sciences (India)

    TECS

    2; thin films; chemical bath deposition technique; d.c. conductivity; thermoelectric .... In a semiconductor, temperature gradient yields the thermo- ... to form the metal complex (Chavan and Sharma 2005) .... Thesis, University of Rajasthan, Jaipur.

  18. Calcium phosphate bioceramics prepared from wet chemically precipitated powders

    Directory of Open Access Journals (Sweden)

    Kristine Salma

    2010-03-01

    Full Text Available In this work calcium phosphates were synthesized by modified wet chemical precipitation route. Contrary to the conventional chemical precipitation route calcium hydroxide was homogenized with planetary mill. Milling calcium oxide and water in planetary ball mill as a first step of synthesis provides a highly dispersed calcium hydroxide suspension. The aim of this work was to study the influence of main processing parameters of wet chemical precipitation synthesis product and to control the morphology, phase and functional group composition and, consequently, thermal stability and microstructure of calcium phosphate bioceramics after thermal treatment. The results showed that it is possible to obtain calcium phosphates with different and reproducible phase compositions after thermal processing (hydroxyapatite [HAp], β-tricalcium phosphate [β-TCP] and HAp/β-TCP by modified wet-chemical precipitation route. The β-TCP phase content in sintered bioceramics samples is found to be highly dependent on the changes in technological parameters and it can be controlled with ending pH, synthesis temperature and thermal treatment. Pure, crystalline and highly thermally stable (up to 1300°C HAp bioceramics with homogenous grainy microstructure, grain size up to 200–250 nm and high open porosity can be successfully obtained by powder synthesized at elevated synthesis temperature of 70°C and stabilizing ending pH at 9.

  19. PREPARATION OF CHEMICALLY WELL-DEFINED CARBOHYDRATE DENDRIMER CONJUGATES

    DEFF Research Database (Denmark)

    2004-01-01

    A method for the synthesis of dendrimer conjugates having a well-defined chemical structure, comprising one or more carbohydrate moieties and one or more immunomodulating substances coupled to a dendrimer, is presented. First, the carbohydrate is bound to the dendrimer in a chemoselective manner...... conjugates and their use in vaccination, production of antibodies, high throughput screening, diagnostic assays and libraries....

  20. Sample Preparation and Identification of Biological, Chemical and Mid-Spectrum Agents

    National Research Council Canada - National Science Library

    Hancock, J. R; Dragon, D. C

    2005-01-01

    A general survey of sample preparation and identification techniques for biological, chemical and mid-spectrum agents was conducted as part of Canada's contribution to a joint NATO Allied Engineering Publication (AEP) handbook...

  1. Oriented Y-typehexagonal ferrite thin films prepared by chemical

    Czech Academy of Sciences Publication Activity Database

    Buršík, Josef; Kužel, R.; Knížek, Karel; Drbohlav, Ivo

    2013-01-01

    Roč. 203, JULY (2013), s. 100-105 ISSN 0022-4596 R&D Projects: GA ČR GA13-03708S Institutional support: RVO:61388980 ; RVO:68378271 Keywords : Y-type hexagonal ferrites * chemical solution deposition * thin films * epitaxial growth Subject RIV: CA - Inorganic Chemistry; BM - Solid Matter Physics ; Magnetism (FZU-D) Impact factor: 2.200, year: 2013

  2. High index of refraction films for dielectric mirrors prepared by metal-organic chemical vapor deposition

    International Nuclear Information System (INIS)

    Brusasco, R.M.

    1989-01-01

    A wide variety of metal oxides with high index of refraction can be prepared by Metal-Organic Chemical Vapor Deposition. We present some recent optical and laser damage results on oxide films prepared by MOCVD which could be used in a multilayer structure for highly reflecting (HR) dielectric mirror applications. The method of preparation affects both optical properties and laser damage threshold. 10 refs., 8 figs., 4 tabs

  3. Sample preparation for combined chemical analysis and bioassay application in water quality assessment

    NARCIS (Netherlands)

    Kolkman, A.; Schriks, M.; Brand, W; Bäuerlein, P.S.; van der Kooi, M.M.E.; van Doorn, R.H.; Emke, E.; Reus, A.; van der Linden, S.; de Voogt, P.; Heringa, M.B.

    2013-01-01

    The combination of in vitro bioassays and chemical screening can provide a powerful toolbox to determine biologically relevant compounds in water extracts. In this study, a sample preparation method is evaluated for the suitability for both chemical analysis and in vitro bioassays. A set of 39

  4. 1.3. Chemical and mineral additives of concretes and water used for concrete mix preparation

    International Nuclear Information System (INIS)

    Saidov, D.Kh.

    2011-01-01

    It is known that chemical and mineral additives increase physicochemical properties of concretes, thus, chemical and mineral additives, including super plasticizer and organo mineral additives are examined in this work. It was noted that along with salt water fresh water can also be used for concrete mix preparation.

  5. Preparation and characterization of a chemically sulfated cashew gum polysaccharide

    Energy Technology Data Exchange (ETDEWEB)

    Moura Neto, Erico de; Maciel, Jeanny da S.; Cunha, Pablyana L. R.; Paula, Regina Celia M. de; Feitosa, Judith P.A., E-mail: judith@dqoi.ufc.br [Departamento de Quimica Organica e Inorganica, Universidade Federal do Ceara, Fortaleza (Brazil)

    2011-09-15

    Cashew gum (CG) was sulfated in pyridine:formamide using chlorosulfonic acid as the reagent. Confirmation of sulfation was obtained by Fourier transform infrared (FTIR) spectroscopy through the presence of an asymmetrical S=O stretching vibration at 1259 cm{sup -1}. The degrees of substitution were 0.02, 0.24 and 0.88 determined from the sulfur percentage. 1D and 2D nuclear magnetic resonance (NMR) data showed that the sulfation occurred at primary carbons. An increase of at least 4% of the solution viscosity was observed due to sulfation. The thermal gravimetric curves (TGA) indicate that the derivatives are stable up to ca. 200 deg C. The sulfated CG is compared to carboxymethylated CG in order to verify the possibility of the use of the former in the preparation of polyelectrolyte complexes; the latter is already being used for this application. (author)

  6. Preparation of hafnium carbide by chemical vapor deposition

    International Nuclear Information System (INIS)

    Hertz, Dominique.

    1974-01-01

    Hard, adhesive coatings of single-phase hafnium carbide were obtained by chemical vapor reaction in an atmosphere containing hafnium tetrachloride, methane and a large excess of hydrogen. By varying the gas phase composition and temperature the zones of formation of the different solid phases were studied and the growth of elementary hafnium and carbon deposits evaluated separately. The results show that the mechanism of hafnium carbide deposition does not hardly involve phenomene of homogeneous-phase methane decomposition or tetrachloride reduction by hydrogen unless the atmosphere is very rich or very poor in methane with respect to tetrachloride. However, hydrogen acting inversely on these two reactions, affects the stoichiometry of the substance deposited. The methane decomposition reaction is fairly slow, the reaction leading to hafnium carbide deposition is faster and that of tetrachloride reduction by hydrogen is quite fast [fr

  7. [Preparation of the database and the Internet (WWW) homepage for regulations on chemicals in Japan].

    Science.gov (United States)

    Yamamoto, M; Morita, M; Kaminuma, T

    1999-01-01

    We prepared a database on chemical regulations in Japan. The regulations consist of "The Law concerning the Examination and Regulation of Manufacture, etc., of Chemical Substances", "Poisonous and Deleterious Substances", Control Law", "Waterworks Law", "Law for the Control of Household Products containing Harmful Substances", and Pesticide Residues in Food Sanitation Law". We also set up a World Wide Web (WWW) homepage containing an explanation of the law as well as chemical names, CAS registry numbers, and standards. The WWW pages contain lists of chemicals and the retrieval page for the database.

  8. Testing Dust Control Preparation with Respect to Mine Employee Exposure to Inhalling Chemical Agents

    Directory of Open Access Journals (Sweden)

    Eugeniusz Orszulik

    2013-01-01

    Full Text Available This paper presents the results of tests used in dust hazard prevention for air-water spraying devices in collieries. The purpose of the tests was to evaluate mine employees’ exposure to inhalling chemical agents when the ZWILKOP ZW-10 preparation is used. The paper presents the results of the measurements of concentration, in a mine atmosphere, of the following chemical agents: hazardous substances 2-(2-butoxyethoxyethanol and 2-ethylhexan-1-ol, constituting ingredients of the preparation at mine employees’ workstations. The tests were performed during work related to the mining of coal in inclined drift C31, seam 415/1-2 on the premises of “Borynia-Zofiówka-Jastrzębie” Hard Coal Mine, Jastrzębie-Zdrój, Poland, using the TELESTO mist systems. Using aqueous solutions for the preparation at concentrations of 15 and 20‰ causes no exceedance of the allowable mine air concentrations for the chemical agents tested.

  9. Preparation of polymeric biomaterials with the aid of radiation-chemical methods

    International Nuclear Information System (INIS)

    Kabanov, Vitalii Ya

    1998-01-01

    The results of the application of radiation-chemical methods for the preparation of polymeric biomaterials are surveyed and treated systematically. The characteristic features of these methods and their advantages and disadvantages are indicated. The properties of polymeric biomaterials prepared using ionising radiation are examined. Particular attention is devoted to studies carried out during the last 10-15 years. The bibliography includes 492 references.

  10. Textural and chemical properties of zinc chloride activated carbons prepared from pistachio-nut shells

    International Nuclear Information System (INIS)

    Yang Ting; Lua, Aik Chong

    2006-01-01

    The effects of activation temperature on the textural and chemical properties of the activated carbons prepared from pistachio-nut shells using zinc chloride activation under both inert nitrogen gas atmosphere and vacuum condition were studied. Relatively low temperature of 400 deg. C was beneficial for the development of pore structures. Too high an activation temperature would lead to sintering of volatiles and shrinkage of the carbon structure. The microstructures and microcrystallinity of the activated carbons prepared were examined by scanning electron microscope and powder X-ray diffraction techniques, respectively, while Fourier transform infrared spectra determined the changes in the surface functional groups at the various stages of preparation

  11. Textural and chemical properties of zinc chloride activated carbons prepared from pistachio-nut shells

    Energy Technology Data Exchange (ETDEWEB)

    Ting, Yang [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Lua, Aik Chong [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)

    2006-12-10

    The effects of activation temperature on the textural and chemical properties of the activated carbons prepared from pistachio-nut shells using zinc chloride activation under both inert nitrogen gas atmosphere and vacuum condition were studied. Relatively low temperature of 400 deg. C was beneficial for the development of pore structures. Too high an activation temperature would lead to sintering of volatiles and shrinkage of the carbon structure. The microstructures and microcrystallinity of the activated carbons prepared were examined by scanning electron microscope and powder X-ray diffraction techniques, respectively, while Fourier transform infrared spectra determined the changes in the surface functional groups at the various stages of preparation.

  12. [Preparation of the database and the homepage on chemical accidents relating to health hazard].

    Science.gov (United States)

    Yamamoto, M; Morita, M; Kaminuma, T

    1998-01-01

    We collected the data on accidents due to chemicals occurred in Japan, and prepared the database. We also set up the World Wide Web homepage containing the explanation on accidents due to chemicals and the retrieval page for the database. We designed the retrieval page so that users can search the data from keywords such as chemicals (e.g. chlorine gas, hydrogen sulfide, pesticides), places (e.g. home, factory, vehicles, tank), causes (e.g. reaction, leakage, exhaust gas) and others (e.g. cleaning, painting, transportation).

  13. Epitaxial ternary nitride thin films prepared by a chemical solution method

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Hongmei [Los Alamos National Laboratory; Feldmann, David M [Los Alamos National Laboratory; Wang, Haiyan [TEXAS A& M; Bi, Zhenxing [TEXAS A& M

    2008-01-01

    It is indispensable to use thin films for many technological applications. This is the first report of epitaxial growth of ternary nitride AMN2 films. Epitaxial tetragonal SrTiN2 films have been successfully prepared by a chemical solution approach, polymer-assisted deposition. The structural, electrical, and optical properties of the films are also investigated.

  14. Zirconia thin film preparation by wet chemical methods at low temperature

    NARCIS (Netherlands)

    Popovici, M.; Graaf, de J.; Verschuuren, M.A.; Graat, P.C.J.; Verheijen, M.A.

    2010-01-01

    In this study the preparation of zirconia thin films with a high refractive index at low temperature is aimed for. Two non-hydrolytic type approaches of wet chemical synthesis are presented. Both by sol–gel and colloid chemistry, highly transmissive, smooth thin films of zirconia cubic and/or

  15. Dielectric behaviour of MgFe2O4 prepared from chemically ...

    Indian Academy of Sciences (India)

    Unknown

    dielectric loss factor. 1. Introduction ... such production of ferrites in year 2005 would be of about. 10,50,000 MTPY. ... factors such as method of preparation, chemical compo- sition, and ..... (VII) Low content of polarizable Fe2+ ions on the octa-.

  16. Concatenation of electrochemical grafting with chemical or electrochemical modification for preparing electrodes with specific surface functionality

    International Nuclear Information System (INIS)

    Verma, Pallavi; Maire, Pascal; Novak, Petr

    2011-01-01

    Surface modified electrodes are used in electro-analysis, electro-catalysis, sensors, biomedical applications, etc. and could also be used in batteries. The properties of modified electrodes are determined by the surface functionality. Therefore, the steps involved in the surface modification of the electrodes to obtain specific functionality are of prime importance. We illustrate here bridging of two routes of surface modifications namely electrochemical grafting, and chemical or electrochemical reduction. First, by electrochemical grafting an organic moiety is covalently immobilized on the surface. Then, either by chemical or by electrochemical route the terminal functional group of the grafted moiety is transformed. Using the former route we prepared lithium alkyl carbonate (-O(CH 2 ) 3 OCO 2 Li) modified carbon with potential applications in batteries, and employing the latter we prepared phenyl hydroxyl amine (-C 6 H 4 NHOH) modified carbon which may find application in biosensors. Benzyl alcohol (-C 6 H 4 CH 2 OH) modified carbon was prepared by both chemical as well as electrochemical route. We report combinations of conjugating the two steps of surface modifications and show how the optimal route of terminal functional group modification depends on the chemical nature of the moiety attached to the surface in the electrochemical grafting step.

  17. Concatenation of electrochemical grafting with chemical or electrochemical modification for preparing electrodes with specific surface functionality

    Energy Technology Data Exchange (ETDEWEB)

    Verma, Pallavi; Maire, Pascal [Paul Scherrer Institut, Electrochemistry Laboratory, Section Electrochemical Energy Storage, CH-5232 Villigen PSI (Switzerland); Novak, Petr, E-mail: petr.novak@psi.c [Paul Scherrer Institut, Electrochemistry Laboratory, Section Electrochemical Energy Storage, CH-5232 Villigen PSI (Switzerland)

    2011-04-01

    Surface modified electrodes are used in electro-analysis, electro-catalysis, sensors, biomedical applications, etc. and could also be used in batteries. The properties of modified electrodes are determined by the surface functionality. Therefore, the steps involved in the surface modification of the electrodes to obtain specific functionality are of prime importance. We illustrate here bridging of two routes of surface modifications namely electrochemical grafting, and chemical or electrochemical reduction. First, by electrochemical grafting an organic moiety is covalently immobilized on the surface. Then, either by chemical or by electrochemical route the terminal functional group of the grafted moiety is transformed. Using the former route we prepared lithium alkyl carbonate (-O(CH{sub 2}){sub 3}OCO{sub 2}Li) modified carbon with potential applications in batteries, and employing the latter we prepared phenyl hydroxyl amine (-C{sub 6}H{sub 4}NHOH) modified carbon which may find application in biosensors. Benzyl alcohol (-C{sub 6}H{sub 4}CH{sub 2}OH) modified carbon was prepared by both chemical as well as electrochemical route. We report combinations of conjugating the two steps of surface modifications and show how the optimal route of terminal functional group modification depends on the chemical nature of the moiety attached to the surface in the electrochemical grafting step.

  18. Effect of biological and chemical preparations on peroxidase activity in leaves of tomato plants

    Directory of Open Access Journals (Sweden)

    Yulia Kolomiets

    2016-10-01

    Full Text Available In terms of treating tomato variety Chaika with chemical preparations with active substances if aluminum phosphate, 570 g/l + phosphorous acid 80 g/,l and mankotseb in concentration of 640 g/kg, the maximum increase in peroxidase activity in leaves of plants was observed in12 hours. In terms of use of biological preparations based on living cells Bacillus subtilis and Azotobacter chroococcum its activity was maximum in 24 hours and ranged from 77.7 to 112.7 un.mg-1•s-1

  19. Young Investigator Proposal, Research Area 7.4 Reactive Chemical Systems: Multifunctional, Bimetallic Nanomaterials Prepared by Atomic Layer Electroless Deposition

    Science.gov (United States)

    2017-09-30

    Report: Young Investigator Proposal, Research Area 7.4 Reactive Chemical Systems: Multifunctional, Bimetallic Nanomaterials Prepared by Atomic Layer ...Chemical Systems: Multifunctional, Bimetallic Nanomaterials Prepared by Atomic Layer Electroless Deposition Report Term: 0-Other Email: pcappillino... Layer Electroless Deposition (ALED, Figure 1) is the ability to tune growth mechanism, hence growth morphology, by altering conditions. In this

  20. Production of radionuclides and preparation of labelled compounds. Nuclear chemical technology

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    A general review is presented of methods of producing radionuclide preparations and labelled compounds, such as their production from natural raw materials, from a nuclear reactor, a particle accelerator, and using radioisotope generators. Also described are the fundamental kinetic relations of nuclear reactions. Basic methods are surveyed of obtaining labelled compounds by chemical synthesis, biosynthesis, exchange reactions, recoil reactions, by the Wilzbach method and the Szillard-Chalmers reaction. (L.K.)

  1. The Electrochemical Characteristics of Hybrid Capacitor Prepared by Chemical Activation of NaOH

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jeong Eun; Bae, Ga Yeong; Yang, Jeong Min; Lee, Jong Dae [Chungbuk National Univ., Chungju (Korea, Republic of)

    2013-06-15

    Active carbons with high specific surface area and micro pore structure were prepared from the coconut shell char using the chemical activation method of NaOH. The preparation process has been optimized through the analysis of experimental variables such as activating chemical agents to char ratio and the flow rate of gas during carbonization. The active carbons with the surface area (2,481m{sup 2}/g) and mean pore size (2.32 nm) were obtained by chemical activation with NaOH. The electrochemical performances of hybrid capacitor were investigated using LiMn{sub 2}O{sub 4}, LiCoO{sub 2} as the positive electrode and prepared active carbon as the negative electrode. The electrochemical behaviors of hybrid capacitor using organic electrolytes (LiPF{sub 6}, TEABF{sub 4}) were characterized by constant current charge/discharge, cyclic voltammetry, cycle and leakage tests. The hybrid capacitor using LiMn{sub 2}O{sub 4}/AC electrodes had better capacitance than other hybrid systems and was able to deliver a specific energy as high as 131 Wh/kg at a specific power of 1,448 W/kg.

  2. The Electrochemical Characteristics of Hybrid Capacitor Prepared by Chemical Activation of NaOH

    International Nuclear Information System (INIS)

    Choi, Jeong Eun; Bae, Ga Yeong; Yang, Jeong Min; Lee, Jong Dae

    2013-01-01

    Active carbons with high specific surface area and micro pore structure were prepared from the coconut shell char using the chemical activation method of NaOH. The preparation process has been optimized through the analysis of experimental variables such as activating chemical agents to char ratio and the flow rate of gas during carbonization. The active carbons with the surface area (2,481m 2 /g) and mean pore size (2.32 nm) were obtained by chemical activation with NaOH. The electrochemical performances of hybrid capacitor were investigated using LiMn 2 O 4 , LiCoO 2 as the positive electrode and prepared active carbon as the negative electrode. The electrochemical behaviors of hybrid capacitor using organic electrolytes (LiPF 6 , TEABF 4 ) were characterized by constant current charge/discharge, cyclic voltammetry, cycle and leakage tests. The hybrid capacitor using LiMn 2 O 4 /AC electrodes had better capacitance than other hybrid systems and was able to deliver a specific energy as high as 131 Wh/kg at a specific power of 1,448 W/kg

  3. Antimony sulfide thin films prepared by laser assisted chemical bath deposition

    International Nuclear Information System (INIS)

    Shaji, S.; Garcia, L.V.; Loredo, S.L.; Krishnan, B.

    2017-01-01

    Highlights: • Antimony sulfide thin films were prepared by normal CBD and laser assisted CBD. • Characterized these films using XRD, XPS, AFM, optical and electrical measurements. • Accelerated growth was observed in the laser assisted CBD process. • These films were photoconductive. - Abstract: Antimony sulfide (Sb_2S_3) thin films were prepared by laser assisted chemical bath deposition (LACBD) technique. These thin films were deposited on glass substrates from a chemical bath containing antimony chloride, acetone and sodium thiosulfate under various conditions of normal chemical bath deposition (CBD) as well as in-situ irradiation of the chemical bath using a continuous laser of 532 nm wavelength. Structure, composition, morphology, optical and electrical properties of the Sb_2S_3 thin films produced by normal CBD and LACBD were analyzed by X-Ray diffraction (XRD), Raman Spectroscopy, Atomic force microscopy (AFM), X-Ray photoelectron spectroscopy (XPS), UV–vis spectroscopy and Photoconductivity. The results showed that LACBD is an effective synthesis technique to obtain Sb_2S_3 thin films for optoelectronic applications.

  4. Antimony sulfide thin films prepared by laser assisted chemical bath deposition

    Energy Technology Data Exchange (ETDEWEB)

    Shaji, S., E-mail: sshajis@yahoo.com [Facultad de Ingeniería Mecánica y Eléctrica, Universidad Autónoma de Nuevo León, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolás de los Garza, Nuevo León, 66455 (Mexico); CIIDIT—Universidad Autónoma de Nuevo León, Apodaca, Nuevo León (Mexico); Garcia, L.V. [Facultad de Ingeniería Mecánica y Eléctrica, Universidad Autónoma de Nuevo León, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolás de los Garza, Nuevo León, 66455 (Mexico); Loredo, S.L. [Centro de Investigación en Materiales Avanzados (CIMAV), Unidad Monterrey, PIIT, Apodaca, Nuevo León (Mexico); Krishnan, B. [Facultad de Ingeniería Mecánica y Eléctrica, Universidad Autónoma de Nuevo León, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolás de los Garza, Nuevo León, 66455 (Mexico); CIIDIT—Universidad Autónoma de Nuevo León, Apodaca, Nuevo León (Mexico); and others

    2017-01-30

    Highlights: • Antimony sulfide thin films were prepared by normal CBD and laser assisted CBD. • Characterized these films using XRD, XPS, AFM, optical and electrical measurements. • Accelerated growth was observed in the laser assisted CBD process. • These films were photoconductive. - Abstract: Antimony sulfide (Sb{sub 2}S{sub 3}) thin films were prepared by laser assisted chemical bath deposition (LACBD) technique. These thin films were deposited on glass substrates from a chemical bath containing antimony chloride, acetone and sodium thiosulfate under various conditions of normal chemical bath deposition (CBD) as well as in-situ irradiation of the chemical bath using a continuous laser of 532 nm wavelength. Structure, composition, morphology, optical and electrical properties of the Sb{sub 2}S{sub 3} thin films produced by normal CBD and LACBD were analyzed by X-Ray diffraction (XRD), Raman Spectroscopy, Atomic force microscopy (AFM), X-Ray photoelectron spectroscopy (XPS), UV–vis spectroscopy and Photoconductivity. The results showed that LACBD is an effective synthesis technique to obtain Sb{sub 2}S{sub 3} thin films for optoelectronic applications.

  5. Characterization and photo-chemical applications of nano-ZnO prepared by wet chemical and thermal decomposition methods

    International Nuclear Information System (INIS)

    Mousa, M.A.; Bayoumy, W.A.A.; Khairy, M.

    2013-01-01

    Graphical abstract: - Highlights: • Nano-ZnO particles were synthesized by soft-wet precipitation and dry methods. • ZnO nanoparticle with different morphologies was obtained. • Nano ZnO samples showed a high photocatalytic activity. • ZnO nanoparticle showed strong ultraviolet emission at room temperature. • The samples showed high biological activity depending on their synthetic method. - Abstract: Nano-crystalline ZnO particles were synthesized using two different routes: soft-wet and dry methods. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to identify the particles structures and morphologies, while X-ray diffraction (XRD) was used for verifying the particles crystal structure. The thermal stabilities of the particles were examined through thermal gravimetric analysis technique and their surface areas were calculated using BET method. Moreover, the photocatalytic activities were evaluated using UV–vis spectroscopy and photoluminescence (PL) characterization. The results showed that all the prepared ZnO samples possess a hexagonal wurtzite structure with high purity. Different particle sizes and morphologies of spheres, rods and wires were obtained depending on the preparation method used. Particle sizes obtained by the dry method are smaller than that found by the wet chemical method. The effects of both particle size and morphology on each of surface as well as optical properties, photocatalytic activity, dye/ZnO solar cell efficiency and biological activity have been studied and discussed

  6. Preparation of activated Carbons from extracted waste biomass by chemical activation

    International Nuclear Information System (INIS)

    Toteva, V.; Nickolov, R.

    2013-01-01

    Full text: Novel biomass precursors for the production of activated carbons (ACs) were studied. ACs were prepared from extracted coffee husks and extracted spent ground coffee - separately or as mixtures with 10, 20 and 30 mass % Bulgarian lignite coal. Activation by potassium hydroxide was employed for all samples. The results obtained show that the surface and porous parameters of the ACs depend on the nature of the initial materials used. The specific surface areas (BET) and the microporosities of ACs obtained from extracted spent ground coffee mixed with 20 mass % Bulgarian lignite coals, are greater than those of the ACs from extracted coffee husks. It is likely that the reason for this result is the chemical composition of the precursors. The coffee husks have less lignin and more holocellulose. The latter undergoes more significant destructive changes in the process of chemical activation. On the contrary, waste ground coffee precursors contain more lignin and less holocellulose. As a result, after the chemical activation, the carbons prepared from extracted spent ground coffee exhibit better porous parameters and higher specific surface areas. key words: activated carbons, extraction, waste biomass

  7. Co3O4 protective coatings prepared by Pulsed Injection Metal Organic Chemical Vapour Deposition

    DEFF Research Database (Denmark)

    Burriel, M.; Garcia, G.; Santiso, J.

    2005-01-01

    of deposition temperature. Pure Co3O4 spinel structure was found for deposition temperatures ranging from 360 to 540 degreesC. The optimum experimental parameters to prepare dense layers with a high growth rate were determined and used to prepare corrosion protective coatings for Fe-22Cr metallic interconnects......Cobalt oxide films were grown by Pulsed Injection Metal Organic Chemical Vapour Deposition (PI-MOCVD) using Co(acac)(3) (acac=acetylacetonate) precursor dissolved in toluene. The structure, morphology and growth rate of the layers deposited on silicon substrates were studied as a function......, to be used in Intermediate Temperature Solid Oxide Fuel Cells. (C) 2004 Elsevier B.V. All rights reserved....

  8. Metal oxide nanostructures: preparation, characterization and functional applications as chemical sensors.

    Science.gov (United States)

    Zappa, Dario; Bertuna, Angela; Comini, Elisabetta; Kaur, Navpreet; Poli, Nicola; Sberveglieri, Veronica; Sberveglieri, Giorgio

    2017-01-01

    Preparation and characterization of different metal oxide (NiO, WO 3 , ZnO, SnO 2 and Nb 2 O 5 ) nanostructures for chemical sensing are presented. p-Type (NiO) and n-type (WO 3 , SnO 2 , ZnO and Nb 2 O 5 ) metal oxide nanostructures were grown on alumina substrates using evaporation-condensation, thermal oxidation and hydrothermal techniques. Surface morphologies and crystal structures were investigated through scanning electron microscopy and Raman spectroscopy. Furthermore, different batches of sensors have been prepared, and their sensing performances towards carbon monoxide and nitrogen dioxide have been explored. Moreover, metal oxide nanowires have been integrated into an electronic nose and successfully applied to discriminate between drinking and contaminated water.

  9. Assessment of activated carbon prepared from corncob by chemical activation with phosphoric acid

    Directory of Open Access Journals (Sweden)

    Gamal O. El-Sayed

    2014-09-01

    Full Text Available Corncob, which is the main waste from corn agricultures in Egypt, has been used as a raw material for the preparation of different activated carbons. Activated carbons (ACs were prepared by chemical activation with concentrated H3PO4 acid; followed by pyrolysis at 400, 500 and 600 °C. Different ACs have been used for the removal of methylene blue (MB dye from aqueous solutions. Batch adsorption experiments were performed as a function of initial dye concentration, contact time, adsorbent dose and pH. Adsorption data were modeled using the Langmuir and Freundlich adsorption isotherms. Adsorption of MB on AC1 (R2=0.9868 and AC2 (R2=0.9810 followed Langmuir model with maximum monolayer sorption capacity of 28.65 and 17.57 mg/g, respectively. Adsorption onto AC3 was better fitted to Freundlich isotherm model (R2=0.9823.

  10. Preparation of carbon nanotubes with different morphology by microwave plasma enhanced chemical vapour deposition

    Energy Technology Data Exchange (ETDEWEB)

    Duraia, El-Shazly M. [Suez Canal University, Faculty of Science, Physics Department, Ismailia (Egypt); Al-Farabi Kazakh National University, 71 Al-Farabi av., 050038 Almaty (Kazakhstan); Institute of Physics and Technology, Ibragimov Street 11, 050032 Almaty (Kazakhstan); Mansurov, Zulkhair [Al-Farabi Kazakh National University, 71 Al-Farabi av., 050038 Almaty (Kazakhstan); Tokmoldin, S.Zh. [Institute of Physics and Technology, Ibragimov Street 11, 050032 Almaty (Kazakhstan)

    2010-04-15

    In this work we present a part of our results about the preparation of carbon nanotube with different morphologies by using microwave plasma enhanced chemical vapour deposition MPECVD. Well aligned, curly, carbon nanosheets, coiled carbon sheets and carbon microcoils have been prepared. We have investigated the effect of the different growth condition parameters such as the growth temperature, pressure and the hydrogen to methane flow rate ratio on the morphology of the carbon nanotubes. The results showed that there is a great dependence of the morphology of carbon nanotubes on these parameters. The yield of the carbon microcoils was high when the growth temperature was 700 C. There is a linear relation between the growth rate and the methane to hydrogen ratio. The effect of the gas pressure on the CNTs was also studied. Our samples were investigated by scanning electron microscope and Raman spectroscopy (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. Protocols for the analytical characterization of therapeutic monoclonal antibodies. II - Enzymatic and chemical sample preparation.

    Science.gov (United States)

    Bobaly, Balazs; D'Atri, Valentina; Goyon, Alexandre; Colas, Olivier; Beck, Alain; Fekete, Szabolcs; Guillarme, Davy

    2017-08-15

    The analytical characterization of therapeutic monoclonal antibodies and related proteins usually incorporates various sample preparation methodologies. Indeed, quantitative and qualitative information can be enhanced by simplifying the sample, thanks to the removal of sources of heterogeneity (e.g. N-glycans) and/or by decreasing the molecular size of the tested protein by enzymatic or chemical fragmentation. These approaches make the sample more suitable for chromatographic and mass spectrometric analysis. Structural elucidation and quality control (QC) analysis of biopharmaceutics are usually performed at intact, subunit and peptide levels. In this paper, general sample preparation approaches used to attain peptide, subunit and glycan level analysis are overviewed. Protocols are described to perform tryptic proteolysis, IdeS and papain digestion, reduction as well as deglycosylation by PNGase F and EndoS2 enzymes. Both historical and modern sample preparation methods were compared and evaluated using rituximab and trastuzumab, two reference therapeutic mAb products approved by Food and Drug Administration (FDA) and European Medicines Agency (EMA). The described protocols may help analysts to develop sample preparation methods in the field of therapeutic protein analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Characteristics of Barium Hexaferrite Nanoparticles Prepared by Temperature-Controlled Chemical Coprecipitation

    International Nuclear Information System (INIS)

    Kwak, Jun Young; Lee, Choong Sub; Kim, Don; Kim, Yeong Il

    2012-01-01

    Ba-ferrite (BaFe 12 O 19 ) nanoparticles were synthesized by chemical coprecipitation method in an aqueous solution. The particle size and the crystallization temperature of the Ba-ferrite nanoparticles were controlled varying the precipitation temperature. The precipitate that was prepared at 0 .deg. C showed the crystal structure of Ba-ferrite in X-ray diffraction when it was calcined at the temperature above 580 .deg. C, whereas what was prepared at 50 .deg. C showed the crystallinity when it was calcined at the temperature higher than about 700 .deg. C. The particle sizes of the synthesized Ba-ferrite were in a range of about 20-30 nm when it was prepared by being precipitated at 0 .deg. C and calcined at 650 .deg. C. When the precipitation temperature increased, the particle size also increased even at the same calcination temperature. The magnetic properties of the Ba-ferrite nanoparticles were also controlled by the synthetic condition of precipitation and calcination temperature. The coercive force could be appreciably lowered without a loss of saturation magnetization when the Ba-ferrite nanoparticles were prepared by precipitation and calcination both at low temperatures

  13. Process for the preparation of fiber-reinforced ceramic composites by chemical vapor deposition

    Science.gov (United States)

    Lackey, Jr., Walter J.; Caputo, Anthony J.

    1986-01-01

    A chemical vapor deposition (CVD) process for preparing fiber-reinforced ceramic composites. A specially designed apparatus provides a steep thermal gradient across the thickness of a fibrous preform. A flow of gaseous ceramic matrix material is directed into the fibrous preform at the cold surface. The deposition of the matrix occurs progressively from the hot surface of the fibrous preform toward the cold surface. Such deposition prevents the surface of the fibrous preform from becoming plugged. As a result thereof, the flow of reactant matrix gases into the uninfiltrated (undeposited) portion of the fibrous preform occurs throughout the deposition process. The progressive and continuous deposition of ceramic matrix within the fibrous preform provides for a significant reduction in process time over known chemical vapor deposition processes.

  14. Effect of borohydride addition rate on chemically prepared amorphous Fe-B particles

    International Nuclear Information System (INIS)

    Koch, C.B.; Morup, S.; Linderoth, S.

    1991-01-01

    Amorphous Fe-B alloys can be prepared by reacting aqueous solutions of Fe salts and NaBH 4 . In this paper the effect of the addition rate of the NaBH 4 solution to the FeSO 4 solution on the precipitate is investigated. The chemical composition of the amorphous alloys formed varies between Fe 79 B 21 and Fe 68 B 32 . The hyperfine parameters of the alloys, derived from Mossbauer spectra, show a decrease from 29 to 25 T of the magnetic hyperfine field and an increase from 0.19 to 0.28 mms -1 of the isomer shift with increasing NaBH 4 addition rate. The results suggest that alloys with different structures but identical composition may be produced by chemical reduction

  15. Preparation, chemical composition and storage studies of quamachil (Pithecellobium dulce L.) aril powder

    OpenAIRE

    Rao, Galla Narsing; Nagender, Allani; Satyanarayana, Akula; Rao, Dubasi Govardhana

    2010-01-01

    Quamachil aril powder samples were prepared and evaluated for chemical composition and sensory quality by packing in two packaging systems during storage for six months. The protein contents were 12.4 and 15.0% in white and pink aril powders respectively. The titrable acidity of white and pink aril powders were 2.4 and 4.8% respectively. Ca and Fe contents in white aril powder samples were 60 and 12 mg/100 g where as in pink aril powder 62 and 16 mg/100 g, respectively. The anthocyanin conten...

  16. Chemical separation of plutonium from air filters and preparation of filaments for resonance ionization mass spectroscopy

    International Nuclear Information System (INIS)

    Eberhardt, K.; Erdmann, N.; Funk, H.; Herrmann, G.; Naehler, A.; Passler, G.; Trautmann, N.; Urban, F.

    1995-01-01

    Resonance ionization mass spectroscopy (RIMS) is used for the determination of plutonium in environmental samples. A chemical procedure based on an ion-exchange technique for the separation of plutonium from a polycarbonate filter is described. The overall yield is about 60% as determined by α-particle spectroscopy. A technique for the subsequent preparation of samples for RIMS measurements is developed. Plutonium is electrode-posited as hydroxide and covered with a thin metallic layer. While heating such a sandwich filament the plutonium hydroxide is reduced to the metal and an atomic beam is evaporated from the surface, as required for RIMS. copyright American Institute of Physics 1995

  17. Preparation and Characterization of Chemical Plugs Based on Selected Hanford Waste Simulants

    International Nuclear Information System (INIS)

    Mattigod, Shas V.; Wellman, Dawn M.; Parker, Kent E.; Cordova, Elsa A.; Gunderson, Katie M.; Baum, Steven R.; Crum, Jarrod V.; Poloski, Adam P.

    2008-01-01

    This report presents the results of preparation and characterization of chemical plugs based on selected Hanford Site waste simulants. Included are the results of chemical plug bench testing conducted in support of the M1/M6 Flow Loop Chemical Plugging/Unplugging Test (TP-RPP-WTP-495 Rev A). These results support the proposed plug simulants for the chemical plugging/ unplugging tests. Based on the available simulant data, a set of simulants was identified that would likely result in chemical plugs. The three types of chemical plugs that were generated and tested in this task consisted of: 1. Aluminum hydroxide (NAH), 2. Sodium aluminosilicate (NAS), and 3. Sodium aluminum phosphate (NAP). While both solvents, namely 2 molar (2 M) nitric acid (HNO3) and 2 M sodium hydroxide (NaOH) at 60 C, used in these tests were effective in dissolving the chemical plugs, the 2 M nitric acid was significantly more effective in dissolving the NAH and NAS plugs. The caustic was only slightly more effecting at dissolving the NAP plug. In the bench-scale dissolution tests, hot (60 C) 2 M nitric acid was the most effective solvent in that it completely dissolved both NAH and NAS chemical plugs much faster (1.5 - 2 x) than 2 M sodium hydroxide. So unless there are operational benefits for the use of caustic verses nitric acid, 2 M nitric acid heated to 60 C should be the solvent of choice for dissolving these chemical plugs. Flow-loop testing was planned to identify a combination of parameters such as pressure, flush solution, composition, and temperature that would effectively dissolve and flush each type of chemical plug from preformed chemical plugs in 3-inch-diameter and 4-feet-long pipe sections. However, based on a review of the results of the bench-top tests and technical discussions, the Waste Treatment Plant (WTP) Research and Technology (R and T), Engineering and Mechanical Systems (EMS), and Operations concluded that flow-loop testing of the chemically plugged pipe sections

  18. CdS thin films prepared by laser assisted chemical bath deposition

    International Nuclear Information System (INIS)

    Garcia, L.V.; Mendivil, M.I.; Garcia Guillen, G.; Aguilar Martinez, J.A.; Krishnan, B.; Avellaneda, D.; Castillo, G.A.; Das Roy, T.K.; Shaji, S.

    2015-01-01

    Highlights: • CdS thin films by conventional CBD and laser assisted CBD. • Characterized these films using XRD, XPS, AFM, optical and electrical measurements. • Accelerated growth was observed in the laser assisted CBD process. • Improved dark conductivity and good photocurrent response for the LACBD CdS. - Abstract: In this work, we report the preparation and characterization of CdS thin films by laser assisted chemical bath deposition (LACBD). CdS thin films were prepared from a chemical bath containing cadmium chloride, triethanolamine, ammonium hydroxide and thiourea under various deposition conditions. The thin films were deposited by in situ irradiation of the bath using a continuous laser of wavelength 532 nm, varying the power density. The thin films obtained during deposition of 10, 20 and 30 min were analyzed. The changes in morphology, structure, composition, optical and electrical properties of the CdS thin films due to in situ irradiation of the bath were analyzed by atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV–vis spectroscopy. The thin films obtained by LACBD were nanocrystalline, photoconductive and presented interesting morphologies. The results showed that LACBD is an effective synthesis technique to obtain nanocrystalline CdS thin films having good optoelectronic properties

  19. CdS thin films prepared by laser assisted chemical bath deposition

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, L.V.; Mendivil, M.I.; Garcia Guillen, G.; Aguilar Martinez, J.A. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); Krishnan, B. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); CIIDIT – Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico); Avellaneda, D.; Castillo, G.A.; Das Roy, T.K. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); Shaji, S., E-mail: sshajis@yahoo.com [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); CIIDIT – Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico)

    2015-05-01

    Highlights: • CdS thin films by conventional CBD and laser assisted CBD. • Characterized these films using XRD, XPS, AFM, optical and electrical measurements. • Accelerated growth was observed in the laser assisted CBD process. • Improved dark conductivity and good photocurrent response for the LACBD CdS. - Abstract: In this work, we report the preparation and characterization of CdS thin films by laser assisted chemical bath deposition (LACBD). CdS thin films were prepared from a chemical bath containing cadmium chloride, triethanolamine, ammonium hydroxide and thiourea under various deposition conditions. The thin films were deposited by in situ irradiation of the bath using a continuous laser of wavelength 532 nm, varying the power density. The thin films obtained during deposition of 10, 20 and 30 min were analyzed. The changes in morphology, structure, composition, optical and electrical properties of the CdS thin films due to in situ irradiation of the bath were analyzed by atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV–vis spectroscopy. The thin films obtained by LACBD were nanocrystalline, photoconductive and presented interesting morphologies. The results showed that LACBD is an effective synthesis technique to obtain nanocrystalline CdS thin films having good optoelectronic properties.

  20. Characterization of Korean Red Ginseng (Panax ginseng Meyer: History, preparation method, and chemical composition

    Directory of Open Access Journals (Sweden)

    Sang Myung Lee

    2015-10-01

    Full Text Available It has been reported that Korean Red Ginseng has been manufactured for 1,123 y as described in the GoRyeoDoGyeong record. The Korean Red Ginseng manufactured by the traditional preparation method has its own chemical component characteristics. The ginsenoside content of the red ginseng is shown as Rg1: 3.3 mg/g, Re: 2.0 mg/g, Rb1: 5.8 mg/g, Rc:1.7 mg/g, Rb2: 2.3 mg/g, and Rd: 0.4 mg/g, respectively. It is known that Korean ginseng generally consists of the main root and the lateral or fine roots at a ratio of about 75:25. Therefore, the red ginseng extract is prepared by using this same ratio of the main root and lateral or fine roots and processed by the historical traditional medicine prescription. The red ginseng extract is prepared through a water extraction (90°C for 14–16 h and concentration process (until its final concentration is 70–73 Brix at 50–60°C. The ginsenoside contents of the red ginseng extract are shown as Rg1: 1.3 mg/g, Re: 1.3 mg/g, Rb1: 6.4 mg/g, Rc:2.5 mg/g, Rb2: 2.3 mg/g, and Rd: 0.9 mg/g, respectively. Arginine-fructose-glucose (AFG is a specific amino-sugar that can be produced by chemical reaction of the process when the fresh ginseng is converted to red ginseng. The content of AFG is 1.0–1.5% in red ginseng. Acidic polysaccharide, which has been known as an immune activator, is at levels of 4.5–7.5% in red ginseng. Therefore, we recommended that the chemical profiles of Korean Red Ginseng made through the defined traditional method should be well preserved and it has had its own chemical characteristics since its traditional development.

  1. Preparation and properties of the magnetic absorbent polymer via the chemical transformation process

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Shengyu, E-mail: liusytyut@sina.com [Department of Mineral Processing, College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Key Laboratory of In-situ Property-improving Mining of Ministry of Education, Taiyuan University of Technology, Taiyuan 030024 (China); Zhang, Suhong, E-mail: zhangsh04@sina.com [Department of Mineral Processing, College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Guo, Jianying; Wen, Jing; Qiao, Yan [Department of Mineral Processing, College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024 (China)

    2017-01-15

    Magnetic polyacrylic acid sodium polymer (MPAAS) was prepared by chemical transformation method. Key parameters were investigated in the synthesis process of the magnetic polymer and an optimum preparation condition was gained. The structure of the magnetic polymer was characterized by X-ray diffraction (XRD), Fourier transform infrared spectrosocopy (FTIR) and scanning electron microscope (SEM). Magnetic property of the magnetic polymer was measured by the magnet and superconducting quantum interference device (SQUID). Both the swelling ratio and kinetics and the water retention ratio and kinetics were investigated. Based on the results, it can be gained that both swelling rate and equilibrium swelling rate were lowered after magnetization while the water retention ability of the magnetic polymer is stronger than that of the polymer. - Highlights: • The preparation mechanism of the magnetic polymer was proposed. • The magnetic property of the magnetic polymer was related to reaction conditions. • Swelling ratio and kinetics of polymer and magnetic polymer were studied. • Water retention ratio and kinetics of polymer and magnetic polymer were studied.

  2. Preparation and properties of the magnetic absorbent polymer via the chemical transformation process

    International Nuclear Information System (INIS)

    Liu, Shengyu; Zhang, Suhong; Guo, Jianying; Wen, Jing; Qiao, Yan

    2017-01-01

    Magnetic polyacrylic acid sodium polymer (MPAAS) was prepared by chemical transformation method. Key parameters were investigated in the synthesis process of the magnetic polymer and an optimum preparation condition was gained. The structure of the magnetic polymer was characterized by X-ray diffraction (XRD), Fourier transform infrared spectrosocopy (FTIR) and scanning electron microscope (SEM). Magnetic property of the magnetic polymer was measured by the magnet and superconducting quantum interference device (SQUID). Both the swelling ratio and kinetics and the water retention ratio and kinetics were investigated. Based on the results, it can be gained that both swelling rate and equilibrium swelling rate were lowered after magnetization while the water retention ability of the magnetic polymer is stronger than that of the polymer. - Highlights: • The preparation mechanism of the magnetic polymer was proposed. • The magnetic property of the magnetic polymer was related to reaction conditions. • Swelling ratio and kinetics of polymer and magnetic polymer were studied. • Water retention ratio and kinetics of polymer and magnetic polymer were studied.

  3. High quality antireflective ZnS thin films prepared by chemical bath deposition

    International Nuclear Information System (INIS)

    Tec-Yam, S.; Rojas, J.; Rejón, V.; Oliva, A.I.

    2012-01-01

    Zinc sulfide (ZnS) thin films for antireflective applications were deposited on glass substrates by chemical bath deposition (CBD). Chemical analysis of the soluble species permits to predict the optimal pH conditions to obtain high quality ZnS films. For the CBD, the ZnCl 2 , NH 4 NO 3 , and CS(NH 2 ) 2 were fixed components, whereas the KOH concentration was varied from 0.8 to 1.4 M. Groups of samples with deposition times from 60 to 120 min were prepared in a bath with magnetic agitation and heated at 90 °C. ZnS films obtained from optimal KOH concentrations of 0.9 M and 1.0 M exhibited high transparency, homogeneity, adherence, and crystalline. The ZnS films presented a band gap energy of 3.84 eV, an atomic Zn:S stoichiometry ratio of 49:51, a transmittance above 85% in the 300–800 nm wavelength range, and a reflectance below 25% in the UV–Vis range. X-ray diffraction analysis revealed a cubic structure in the (111) orientation for the films. The thickness of the films was tuned between 60 nm and 135 nm by controlling the deposition time and KOH concentration. The incorporation of the CBD-ZnS films into ITO/ZnS/CdS/CdTe and glass/Mo/ZnS heterostructures as antireflective layer confirms their high optical quality. -- Highlights: ► High quality ZnS thin films were prepared by chemical bath deposition (CBD). ► Better CBD-ZnS films were achieved by using 0.9 M-KOH concentration. ► Reduction in the reflectance was obtained for ZnS films used as buffer layers.

  4. A comparison of the microstructures and electrochemical capacitive properties of 2 graphenes prepared by arc discharge method and chemical method

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, H.; Yang, Y. [Research Inst. of Chemical Defense, Beijing (China); Univ. of Science and Technology, Beijing (China); Cao, G.; Xu, B. [Research Inst. of Chemical Defense, Beijing (China)

    2010-07-01

    In this study, 2 kinds of graphene materials were prepared using both arc discharge and chemical methods. The pore structures and electrochemical capacitive properties of the materials were investigated. A mesopore structure was obtained for the graphene prepared using the arc discharge method, with a capacitance of 12.9 F/g and a high rate capability when used in electrochemical applications. The graphene prepared with the chemical method demonstrated a more highly developed micropore structure and capacitances greater than 70 F/g. However, rate performance for the graphene was normal. 2 figs.

  5. Electrical properties of the n-ZnO/c-Si heterojunction prepared by chemical spray pyrolysis

    International Nuclear Information System (INIS)

    Romero, R.; Lopez, M.C.; Leinen, D.; Martin, F.; Ramos-Barrado, J.R.

    2004-01-01

    Electrical, structural and compositional properties of n-ZnO/c-Si heterojunctions prepared by chemical spray pyrolysis on single-crystal n-type and p-type monocrystalline silicon(1 0 0) substrates are examined with the C-V method and admittance spectroscopy at temperature ranges between 223 and 373 K. The n-ZnO/c-Si heterojunctions show a height barrier consistent with the difference in energy of the work functions of Si and ZnO; however, the n-ZnO:Al/c-Si heterojunctions present a more complex behavior due to the defects at or near the n-ZnO:Al/c-Si interface, causing a Fermi energy pinning

  6. Zinc Sulfide Buffer Layer for CIGS Solar Cells Prepared by Chemical Bath Deposition

    Directory of Open Access Journals (Sweden)

    Rui-Wei You

    2016-11-01

    Full Text Available In this study, ZnS thin films were successfully synthesized by chemical bath deposition (CBD with starting materials of NH2-NH2, SC(NH22, and ZnSO4‧7H2O. ZnS thin films were deposited with different time on glass substrates by CBD at 80oC and pH=9. Based on X-ray diffraction (XRD patterns, it is found that the ZnS thin films exhibit cubic polycrystalline phase. It was found that the optimum deposition time is 90 min for preparing ZnS thin film that is suitable as buffer layer for CuIn1-xGaxSe2 solar cells. The thin film deposited for 90 min has high transmittance up to 80% in the spectra range from 350 nm to 800 nm, and the optical band gap is about 3.59 eV.

  7. Highly sensitive methanol chemical sensor based on undoped silver oxide nanoparticles prepared by a solution method

    International Nuclear Information System (INIS)

    Rahman, M.M.; Khan, S.B.; Asiri, A.M.; Jamal, A.; Faisal, M.

    2012-01-01

    We have prepared silver oxide nanoparticles (NPs) by a simple solution method using reducing agents in alkaline medium. The resulting NPs were characterized by UV-vis and FT-IR spectroscopy, X-ray powder diffraction, and field-emission scanning electron microscopy. They were deposited on a glassy carbon electrode to give a sensor with a fast response towards methanol in liquid phase. The sensor also displays good sensitivity and long-term stability, and enhanced electrochemical response. The calibration plot is linear (r 2 = 0.8294) over the 0.12 mM to 0.12 M methanol concentration range. The sensitivity is ∼ 2.65 μAcm -2 mM -1 , and the detection limit is 36.0 μM (at a SNR of 3). We also discuss possible future prospective uses of this metal oxide semiconductor nanomaterial in terms of chemical sensing. (author)

  8. Preparation of functional composite materials based on chemically derived graphene using solution process

    International Nuclear Information System (INIS)

    Kim, M; Hyun, W J; Mun, S C; Park, O O

    2015-01-01

    Chemically derived graphenes were assembled into functional composite materials using solution process from stable solvent dispersion. We have developed foldable electronic circuits on paper substrates using vacuum filtration of graphene nanoplates dispersion and a selective transfer process without need for special equipment. The electronic circuits on paper substrates revealed only a small change in conductance under various folding angles and maintained an electronic path after repetitive folding and unfolding. We also prepared flexible. binder-free graphene paper-like materials by addition of graphene oxide as a film stabilizer. This graphene papers showed outstanding electrical conductivity up to 26,000 S/m and high charge capacity as an anode in lithium-ion battery without any post-treatments. For last case, multi-functional thin film structures of graphene nanoplates were fabricated by using layer-by-layer assembly technique, showing optical transparency, electrical conductivity and enhanced gas barrier property. (paper)

  9. Preparation of nanocrystalline ZnS by a new chemical bath deposition route

    Energy Technology Data Exchange (ETDEWEB)

    Sartale, S.D. [Department of Heterogeneous Material Systems (SE2), Hahn-Meitner-Institut, Glienicker Strasse 100, D-14109, Berlin (Germany); Sankapal, B.R. [Department of Heterogeneous Material Systems (SE2), Hahn-Meitner-Institut, Glienicker Strasse 100, D-14109, Berlin (Germany); Lux-Steiner, M. [Department of Heterogeneous Material Systems (SE2), Hahn-Meitner-Institut, Glienicker Strasse 100, D-14109, Berlin (Germany); Ennaoui, A. [Department of Heterogeneous Material Systems (SE2), Hahn-Meitner-Institut, Glienicker Strasse 100, D-14109, Berlin (Germany)]. E-mail: ennaoui@hmi.de

    2005-06-01

    We report a new chemical bath deposition route for the preparation of dense, compact and uniform nanocrystalline ZnS thin films, where thiourea acts as a complexing agent as well as a source of sulfide ions. The structural and morphological characterizations suggest that the film and the residual powder in the bath are formed by the aggregation of clusters of ZnS, namely cluster-by-cluster growth mechanism. X-ray diffraction (XRD) and HRTEM analyses indicate that the film and powder formed in the bath have cubic zinkblende structure. The films have high transmittance of about 75% in the visible region. Post-deposition annealing in Ar slightly improves the crystallinity and decreases the optical bandgap with increasing the annealing temperature.

  10. Preparation of nanocrystalline ZnS by a new chemical bath deposition route

    International Nuclear Information System (INIS)

    Sartale, S.D.; Sankapal, B.R.; Lux-Steiner, M.; Ennaoui, A.

    2005-01-01

    We report a new chemical bath deposition route for the preparation of dense, compact and uniform nanocrystalline ZnS thin films, where thiourea acts as a complexing agent as well as a source of sulfide ions. The structural and morphological characterizations suggest that the film and the residual powder in the bath are formed by the aggregation of clusters of ZnS, namely cluster-by-cluster growth mechanism. X-ray diffraction (XRD) and HRTEM analyses indicate that the film and powder formed in the bath have cubic zinkblende structure. The films have high transmittance of about 75% in the visible region. Post-deposition annealing in Ar slightly improves the crystallinity and decreases the optical bandgap with increasing the annealing temperature

  11. Synthesis and spectroscopic characterization of gold nanobipyramids prepared by a chemical reduction method

    International Nuclear Information System (INIS)

    Ngo, Vo Ke Thanh; Huynh, Trong Phat; Nguyen, Dang Giang; Nguyen, Hoang Phuong Uyen; Lam, Quang Vinh; Huynh, Thanh Dat

    2015-01-01

    Gold nanobipyramids (NBPs) have attracted much attention because they have potential for applications in smart sensing devices, such as medical diagnostic equippments. This is due to the fact that they show more advantageous plasmonic properties than other gold nanostructures. We describe a chemical reduction method for synthesizing NBPs using conventional heating with ascorbic acid reduction and cetyltrimethylamonium bromide (CTAB) + AgNO_3 as capping agents. The product was characterized by ultraviolet–visible spectroscopy (UV–vis), Fourier transmission infrared spectroscopy (FTIR), transmission electron microscopy (TEM), x-ray powder diffraction (XRD). The results showed that gold nanoparticles were formed with bipyramid shape (tip-to-tip distance of 88.4 ± 9.4 nm and base length of 29.9 ± 3.2 nm) and face-centered-cubic crystalline structure. Optimum parameters for preparation of NBPs are also found. (paper)

  12. Synthesis and spectroscopic characterization of gold nanobipyramids prepared by a chemical reduction method

    Science.gov (United States)

    Thanh Ngo, Vo Ke; Phat Huynh, Trong; Giang Nguyen, Dang; Phuong Uyen Nguyen, Hoang; Lam, Quang Vinh; Dat Huynh, Thanh

    2015-12-01

    Gold nanobipyramids (NBPs) have attracted much attention because they have potential for applications in smart sensing devices, such as medical diagnostic equippments. This is due to the fact that they show more advantageous plasmonic properties than other gold nanostructures. We describe a chemical reduction method for synthesizing NBPs using conventional heating with ascorbic acid reduction and cetyltrimethylamonium bromide (CTAB) + AgNO3 as capping agents. The product was characterized by ultraviolet-visible spectroscopy (UV-vis), Fourier transmission infrared spectroscopy (FTIR), transmission electron microscopy (TEM), x-ray powder diffraction (XRD). The results showed that gold nanoparticles were formed with bipyramid shape (tip-to-tip distance of 88.4 ± 9.4 nm and base length of 29.9 ± 3.2 nm) and face-centered-cubic crystalline structure. Optimum parameters for preparation of NBPs are also found.

  13. Fabrication and Characterization of Zinc Sulfide Nanoparticles and Nanocomposites Prepared via a Simple Chemical Precipitation Method

    Directory of Open Access Journals (Sweden)

    Kambiz Hedayati

    2016-07-01

    Full Text Available In this research zinc sulfide (ZnS nanoparticles and nanocomposites powders were prepared by chemical precipitation method using zinc acetate and various sulfur sources. The ZnS nanoparticles were characterized by X-ray diffraction, scanning electron microscopy, ultraviolet-visible and fourier transform infra-red. The structure of nanoparticles was studied using X-ray diffraction pattern. The crystallite size of ZnS nanoparticles was calculated by Debye–Scherrer formula. Morphology of nano-crystals was observed and investigated using the scanning electron microscopy. The grain size of zinc sulfide nanoparticles were in suitable agreement with the crystalline size calculated by X-ray diffraction results. The optical properties of particles were studied with ultraviolet-visible absorption spectrum.

  14. Effect of Organic Solvents in Preparation of Silica-Based Chemical Gel Decontaminates for Decontamination of Nuclear Facilities

    International Nuclear Information System (INIS)

    Yoon, Suk Bon; Jung, Chong Hun; Kim, Chang Ki; Choi, Byung Seon; Lee, Kune Woo; Moon, Jei Kwon

    2011-01-01

    Decontamination of nuclear facilities is necessary to reduce the radiation field during normal operations and decommissioning of complex equipment such as stainless steel components, other iron-based steel and alloys, metal surfaces, structural materials and so on. Chemical decontamination technology in particular is a highly effective method to remove the radioactive contamination through a chemical dissolution or a redox reaction. However, this method has the serious drawback due to the generation of large amounts of the radioactive liquid wastes. Recently, a few literatures have been reported for the preparation of the chemical gel decontaminants to reduce the amount of the radioactive liquid wastes and to enhance the decontamination efficiency through increasing the contact time between the gels and the radioactive contaminants. In the preparation of the chemical gels, the control of the viscosity highly depends on the amount of a coviscosifier used among the components of the chemical gels consisted of a viscosifier, a coviscosifier, and a chemical decontaminant. In this works, a new effective method for the preparation of the chemical gel was investigated by introducing the organic solvents. The mixture solution of the coviscosifier and organic solvent was more effective in the control of the viscosity compared with that of the coviscosifier only in gels. Furthermore, the decontamination efficiency of the chemical gels measured by using the multi-channel analyzer (MCA) showed the high decontamination factor for Co-60 and Cs-137 contaminated on the surface of the stainless steel 304

  15. Occurrence of two-photon absorption saturation in Ag nanocolloids, prepared by chemical reduction method

    Energy Technology Data Exchange (ETDEWEB)

    Rahulan, K. Mani, E-mail: krahul.au@gmail.com [Department of Physics, Anna University, Chennai (India); Ganesan, S. [Department of Physics, Anna University, Chennai (India); Aruna, P., E-mail: aruna@annauniv.edu [Department of Physics, Anna University, Chennai (India)

    2012-09-01

    Highlights: Black-Right-Pointing-Pointer Ag nanocolloids were synthesized via chemical reduction method. Black-Right-Pointing-Pointer The molecules of PVP play an important role in growth and agglomeration of silver nanocolloids. Black-Right-Pointing-Pointer Saturation behaviour followed by two photon absorption was responsible for good optical limiting characteristics in these nanocolloids. Black-Right-Pointing-Pointer The nonlinear optical parameters calculated from the data showed that these materials could be used as efficient optical limiters. - Abstract: Silver nanocolloids stabilized with polyvinyl pyrrolidone (PVP) have been prepared from (AgNO{sub 3}) by a chemical reduction method, involving the intermediate preparation of (Ag{sub 2}O) colloidal dispersions in the presence of sodium dodecycle sulfate as a surfactant and formaldehyde as reducing agent. The molecules of PVP play an important role in growth and agglomeration of silver nanocolloids. The formation of Ag nanocolloids was studied from the UV-vis absorption characteristics. An energy dispersive X-ray (EDX) spectrum and X-ray diffraction peak of the nanoparticles showed the highly crystalline nature of silver structure. The particle size was found to be 40 nm as analyzed from Field emission scanning electron microscopy (FESEM). The nonlinear optical and optical limiting properties of these nanoparticle dispersions were studied by using the Z-scan technique at 532 nm. Experimental results show that the Ag nanocolloids possess strong optical limiting effect, originated from absorption saturation followed by two-photon mechanism. The data show that Ag nanocolloids have great potential for nonlinear optical devices.

  16. Morphology of CdSe films prepared by chemical bath deposition: The role of substrate

    International Nuclear Information System (INIS)

    Simurda, M.; Nemec, P.; Formanek, P.; Nemec, I.; Nemcova, Y.; Maly, P.

    2006-01-01

    We combine optical spectroscopy and transmission electron microscopy to study the growth and the structural morphology of CdSe films prepared by chemical bath deposition (CBD) on two considerably different substrates. The films grown on glass are compact and strongly adherent to the substrate. On the contrary, the films deposited on carbon-coated glass (with approx. 20 nm thick amorphous carbon layer) are only loosely adherent to the substrate. Using transmission electron microscopy we revealed that even though the films grown on both substrates are assembled from closely spaced nanocrystals with diameter of about 5 nm, the films morphology on the sub-micrometer scale is considerably different in the two cases. While the films deposited on glass are rather compact, the films prepared on carbon layer have high porosity and are formed by interconnected spheres which size is dependent on the duration of deposition (e.g. 155 nm for 6 h and 350 nm for 24 h). This shows that the choice of the substrate for CBD has a stronger influence on the sub-micrometer film morphology than on the properties of individual nanocrystals forming the film

  17. Alloy composition dependence of formation of porous Ni prepared by rapid solidification and chemical dealloying

    Energy Technology Data Exchange (ETDEWEB)

    Qi Zhen [Key Laboratory of Liquid Structure and Heredity of Materials, Shandong University, Jingshi Road 73, Jinan 250061 (China); Zhang Zhonghua [Key Laboratory of Liquid Structure and Heredity of Materials, Shandong University, Jingshi Road 73, Jinan 250061 (China)], E-mail: zh_zhang@sdu.edu.cn; Jia Haoling [Key Laboratory of Liquid Structure and Heredity of Materials, Shandong University, Jingshi Road 73, Jinan 250061 (China); Qu Yingjie [Shandong Labor Occupational Technology College, Jingshi Road 388, Jinan 250022 (China); Liu Guodong; Bian Xiufang [Key Laboratory of Liquid Structure and Heredity of Materials, Shandong University, Jingshi Road 73, Jinan 250061 (China)

    2009-03-20

    In this paper, the effect of alloy composition on the formation of porous Ni catalysts prepared by chemical dealloying of rapidly solidified Al-Ni alloys has been investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis and N{sub 2} adsorption experiments. The experimental results show that rapid solidification and alloy composition have a significant effect on the phase constituent and microstructure of Al-Ni alloys. The melt spun Al-20 at.% Ni alloy consists of {alpha}-Al, NiAl{sub 3} and Ni{sub 2}Al{sub 3}, while the melt spun Al-25 and 31.5 at.% Ni alloys comprise NiAl{sub 3} and Ni{sub 2}Al{sub 3}. Moreover, the formation and microstructure of the porous Ni catalysts are dependent upon the composition of the melt spun Al-Ni alloys. The morphology and size of Ni particles in the Ni catalysts inherit from those of grains in the melt spun Al-Ni alloys. Rapid solidification can extend the alloy composition of Al-Ni alloys suitable for preparation of the Ni catalysts, and obviously accelerate the dealloying process of the Al-Ni alloys.

  18. Preparation of Ti species coating hydrotalcite by chemical vapor deposition for photodegradation of azo dye.

    Science.gov (United States)

    Xiao, Gaofei; Zeng, HongYan; Xu, Sheng; Chen, ChaoRong; Zhao, Quan; Liu, XiaoJun

    2017-10-01

    TiO 2 in anatase crystal phase is a very effective catalyst in the photocatalytic oxidation of organic compounds in water. To improve its photocatalytic activity, the Ti-coating MgAl hydrotalcite (Ti-MgAl-LDH) was prepared by chemical vapor deposition (CVD) method. Response surface method (RSM) was employed to evaluate the effect of Ti species coating parameters on the photocatalytic activity, which was found to be affected by the furnace temperature, N 2 flow rate and influx time of precursor gas. Application of RSM successfully increased the photocatalytic efficiency of the Ti-MgAl-LDH in methylene blue photodegradation under UV irradiation, leading to improved economy of the process. According to the results from X-ray diffraction, scanning electron microscopy, Brunner-Emmet-Teller and Barrett-Joyner-Hallender, thermogravimetric and differential thermal analysis, UV-vis diffuse reflectance spectra analyses, the Ti species (TiO 2 or/and Ti 4+ ) were successfully coated on the MgAl-LDH matrix. The Ti species on the surface of the Ti-MgAl-LDH lead to a higher photocatalytic performance than commercial TiO 2 -P25. The results suggested that CVD method provided a new approach for the industrial preparation of Ti-coating MgAl-LDH material with good photocatalytic performances. Copyright © 2017. Published by Elsevier B.V.

  19. Preparation of Al2O3/Mo nanocomposite powder via chemical route and spray drying

    International Nuclear Information System (INIS)

    Lo, M.; Cheng, F.; Wei, W.J.

    1996-01-01

    A route to prepare nanometer-sized Mo particulates in Al 2 O 3 was attempted by a combination of solution reactions in molecular scale and forcing precipitation by a spray-drying technique. MoO 3 was first dissolved in ammonia water and then added in the slurry with high purity, submicrometer Al 2 O 3 powder. Mixed suspension was spray-dried, and then the dried granules were reduced by hydrogen gas and further hot-pressing to a bulky composite at various temperatures. Dissolution of Mo oxide, adsorption reactions on alumina surface, and surface potential of alumina particles in homogeneous ammonia suspension were studied. Characterization of the granules, including compactability, flowing properties, surface morphology, grain growth of Mo and Al 2 O 3 , and mixing homogeneity, were examined. Homogeneity of the spray-dried granules was determined by the calculation of mixing index and the observation of the microstructure of sintered body. The existence of intergranular, intragranular, and nanosized Mo particulates within Al 2 O 3 grains was observed by transmission electron microscopy (TEM). All the evidences revealed that homogeneous composites with nanometer-sized Mo had been successfully prepared by this attempt with the proposed chemical route and following spray-drying process. copyright 1996 Materials Research Society

  20. Faraday effect of polycrystalline bismuth iron garnet thin film prepared by mist chemical vapor deposition method

    International Nuclear Information System (INIS)

    Yao, Situ; Kamakura, Ryosuke; Murai, Shunsuke; Fujita, Koji; Tanaka, Katsuhisa

    2017-01-01

    We have synthesized polycrystalline thin film composed of a single phase of metastable bismuth iron garnet, Bi_3Fe_5O_1_2, on a fused silica substrate, one of the most widely utilized substrates in the solid-state electronics, by using mist chemical vapor deposition (mist CVD) method. The phase purity and stoichiometry are confirmed by X-ray diffraction and Rutherford backscattering spectrometry. The resultant thin film shows a small surface roughness of 3.251 nm. The saturation magnetization at room temperature is 1200 G, and the Faraday rotation angle at 633 nm reaches −5.2 deg/μm. Both the magnetization and the Faraday rotation angles are somewhat higher than those of polycrystalline BIG thin films prepared by other methods. - Highlights: • Thin film of polycrystalline Bi_3Fe_5O_1_2 was prepared by the mist CVD method. • Optimized conditions were found for the synthesis of single phase of Bi_3Fe_5O_1_2. • The Faraday rotation angle at 633 nm is –5.2 deg/μm at room temperature. • The Faraday rotation is interpreted by the electronic transitions of Fe"3"+ ions.

  1. Faraday effect of polycrystalline bismuth iron garnet thin film prepared by mist chemical vapor deposition method

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Situ; Kamakura, Ryosuke; Murai, Shunsuke; Fujita, Koji; Tanaka, Katsuhisa, E-mail: tanaka@dipole7.kuic.kyoto-u.ac.jp

    2017-01-15

    We have synthesized polycrystalline thin film composed of a single phase of metastable bismuth iron garnet, Bi{sub 3}Fe{sub 5}O{sub 12}, on a fused silica substrate, one of the most widely utilized substrates in the solid-state electronics, by using mist chemical vapor deposition (mist CVD) method. The phase purity and stoichiometry are confirmed by X-ray diffraction and Rutherford backscattering spectrometry. The resultant thin film shows a small surface roughness of 3.251 nm. The saturation magnetization at room temperature is 1200 G, and the Faraday rotation angle at 633 nm reaches −5.2 deg/μm. Both the magnetization and the Faraday rotation angles are somewhat higher than those of polycrystalline BIG thin films prepared by other methods. - Highlights: • Thin film of polycrystalline Bi{sub 3}Fe{sub 5}O{sub 12} was prepared by the mist CVD method. • Optimized conditions were found for the synthesis of single phase of Bi{sub 3}Fe{sub 5}O{sub 12}. • The Faraday rotation angle at 633 nm is –5.2 deg/μm at room temperature. • The Faraday rotation is interpreted by the electronic transitions of Fe{sup 3+} ions.

  2. Characterization of mesoporous carbon prepared from date stems by H3PO4 chemical activation

    International Nuclear Information System (INIS)

    Hadoun, H.; Sadaoui, Z.; Souami, N.; Sahel, D.; Toumert, I.

    2013-01-01

    The present work was focused on the determination of texture, morphology, crystanillity and oxygenated surface groups characteristics of an activated carbon prepared from date stems. Chemical activation of this precursor at different temperatures (450, 550 and 650 °C) was adopted using phosphoric acid as dehydrating agent at (2/1) impregnation ratio. Fourier transform infrared spectroscopy study was carried out to identify surface groups in date stems activated carbons. The microscopic structure was examined by nitrogen adsorption at 77 K. The interlayer spacing (d 200 and d 100 ), stack height (L c ), stack width (L a ) and effective dimension L of the turbostratic crystallites (microcrystallite) in the date stems activated carbons were estimated from X-ray diffraction data (XRD). Results yielded a surface area, S BET , and total pore volume of 682, 1455, 1319 m 2 /g and 0,343, 1,045 and 0.735 cm 3 /g, for the carbon prepared at 450, 550 and 650 °C, respectively. Scanning electron microscopy exhibits a highly developed porosity which is in good agreement with the porous texture derived from gas adsorption data and these results confirm that the activated carbon is dominated by network of slit-shaped mesopores morphology and in some cases by varied micropores morphologies.

  3. Structure and composition of chemically prepared and vacuum annealed InSb(0 0 1) surfaces

    International Nuclear Information System (INIS)

    Tereshchenko, O.E.

    2006-01-01

    The InSb(0 0 1) surfaces chemically treated in HCl-isopropanol solution and annealed in vacuum were studied by means of X-ray photoelectron spectroscopy (XPS), low energy electron diffraction (LEED) and electron energy-loss spectroscopy (EELS). The HCl-isopropanol treatment removes indium and antimony oxides and leaves on the surface about 3 ML of physisorbed overlayer, containing indium chlorides and small amounts of antimony, which can be thermally desorbed at 230 deg. C. The residual carbon contaminations were around 0.2-0.4 ML and consisted of the hydrocarbon molecules. These hydrocarbon contaminations were removed from the surface together with the indium chlorides and antimony overlayer. With increased annealing temperature, a sequence of reconstructions were identified by LEED: (1 x 1), (1 x 3), (4 x 3), and (4 x 1)/c(8 x 2), in the order of decreasing Sb/In ratio. The structural properties of chemically prepared InSb(0 0 1) surface were found to be similar to those obtained by decapping of Sb-capped epitaxial layers

  4. FragIt: a tool to prepare input files for fragment based quantum chemical calculations.

    Directory of Open Access Journals (Sweden)

    Casper Steinmann

    Full Text Available Near linear scaling fragment based quantum chemical calculations are becoming increasingly popular for treating large systems with high accuracy and is an active field of research. However, it remains difficult to set up these calculations without expert knowledge. To facilitate the use of such methods, software tools need to be available to support these methods and help to set up reasonable input files which will lower the barrier of entry for usage by non-experts. Previous tools relies on specific annotations in structure files for automatic and successful fragmentation such as residues in PDB files. We present a general fragmentation methodology and accompanying tools called FragIt to help setup these calculations. FragIt uses the SMARTS language to locate chemically appropriate fragments in large structures and is applicable to fragmentation of any molecular system given suitable SMARTS patterns. We present SMARTS patterns of fragmentation for proteins, DNA and polysaccharides, specifically for D-galactopyranose for use in cyclodextrins. FragIt is used to prepare input files for the Fragment Molecular Orbital method in the GAMESS program package, but can be extended to other computational methods easily.

  5. Comparison of Three Sample Preparation Methods for Analysis of Chemical Warfare Agent Stimulants in Water

    International Nuclear Information System (INIS)

    Alessandro Sassolini

    2015-01-01

    Analytical chemistry in CBRNe (Chemical Biological Radiological Nuclear explosive) context requires not only high quality data; quickness, ruggedness and robustness are also mandatory. In this work, three samples preparation methods were compared using several organophosphorus pesticides as test compounds, used as stimulants of nerve CWA (Chemical Warfare Agents) to choose the one with best characteristics. Result was obtained better with the Dispersive Liquid-Liquid Micro Extraction (DLLME), relatively new in CBRNe field, obtaining uncertainty for different simulants between 8 and 15 % while a quantification limit between 0.01 and 0.08 μg/ l. To optimize this extraction method, different organo chlorinated solvents also tested but not relevant difference in these tests was obtained. In this work, all samples were analyzed by using a gas chromatography coupled with mass spectrometer (GC-MS) and also with Gas Chromatograph coupled with Nitrogen Phosphorous Detector (NPD) for DLLME samples to evaluate a low cost and rugged instrument adapt to field analytical methods with good performance in terms of uncertainty and sensibility even if poorer respect to the mass spectrometry. (author)

  6. Preparation and chemical stability of iron-nitride-coated iron microparticles

    International Nuclear Information System (INIS)

    Luo Xin; Liu Shixiong

    2007-01-01

    Iron-nitride-coated iron microparticles were prepared by nitridation of the surface of iron microparticles with ammonia gas at a temperature of 510 deg. C. The phases, composition, morphology, magnetic properties, and chemical stability of the particles were studied. The phases were α-Fe, ε-Fe 3 N, and γ-Fe 4 N. The composition varied from the core to the surface, with 99.8 wt% Fe in the core, and 93.8 wt% Fe and 6 wt% N in the iron-nitride coating. The thickness of the iron-nitride coating was about 0.28 μm. The chemical stability of the microparticles was greatly improved, especially the corrosion resistance in corrosive aqueous media. The saturation magnetization and the coercive force were 17.1x10 3 and 68 kA/m, respectively. It can be concluded that iron-nitride-coated iron microparticles will be very useful in many fields, such as water-based magnetorheological fluids and polishing fluids

  7. Preparation of micro/nano-fibrous brushite coating on titanium via chemical conversion for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Bing [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Ji’nan 250061 (China); School of Materials Science and Engineering, Shandong University, Ji’nan, 250061 (China); Suzhou Institute, Shandong University, Suzhou, 215123 (China); Guo, Yong-yuan [Orthopedic Department, Qilu Hospital of Shandong University, Ji’nan, 250012 (China); Xiao, Gui-yong [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Ji’nan 250061 (China); School of Materials Science and Engineering, Shandong University, Ji’nan, 250061 (China); Suzhou Institute, Shandong University, Suzhou, 215123 (China); Lu, Yu-peng, E-mail: biosdu@sdu.edu.cn [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Ji’nan 250061 (China); School of Materials Science and Engineering, Shandong University, Ji’nan, 250061 (China); Suzhou Institute, Shandong University, Suzhou, 215123 (China)

    2017-03-31

    Highlights: • A chemical conversion brushite coating was prepared on titanium. • The coating exhibits fibrous morphology in micro/nano-scale. • The surface of the coating shows high hydrophilicity and corrosion resistance in the simulated body fluid. • An improvement of cell response was observed on the surface of coated Ti compared to that of the uncoated. - Abstract: Calcium phosphate coatings have been applied on the surface of Ti implants to realize better osseointegration. The formation of dicalcium phosphate dihydrate (CaHPO{sub 4}·2H{sub 2}O), mineralogically named brushite on pure Ti substrate has been investigated via chemical conversion method. Coating composition and microstructure have been investigated by X-ray diffractometer, Fourier transform infrared spectrometer and field emission scanning electron microscope. The results reveal that the coatings are composed of high crystalline brushite with minor scholzite (CaZn{sub 2}(PO{sub 4}){sub 2}·2H{sub 2}O). A micro/nano-scaled fibrous morphology can be produced in the acidic chemical conversion bath with pH 5.00. The surface of the fibrous brushite coating exhibits high hydrophilicity and corrosion resistance in the simulated body fluid. The osteoblast cells grow and spread actively on the coated samples and the proliferation numbers and alkaline phosphate activities of the cells improve significantly compared to the uncoated Ti. It is suggested that the micro/nano-fibrous brushite coating can be a potential approach to improve the osteoinductivity and osteoconductivity of Ti implant, due to its similarity in morphology and dimension to inorganic components of biological hard tissues, and favorable responses to the osteoblasts.

  8. Adsorption studies of methylene blue and phenol onto vetiver roots activated carbon prepared by chemical activation.

    Science.gov (United States)

    Altenor, Sandro; Carene, Betty; Emmanuel, Evens; Lambert, Jacques; Ehrhardt, Jean-Jacques; Gaspard, Sarra

    2009-06-15

    Vetiver roots have been utilized for the preparation of activated carbon (AC) by chemical activation with different impregnation ratios of phosphoric acid, X(P) (gH(3)PO(4)/g precursor): 0.5:1; 1:1 and 1.5:1. Textural characterization, determined by nitrogen adsorption at 77K shows that mixed microporous and mesoporous structures activated carbons (ACs) with high surface area (>1000 m(2)/g) and high pore volume (up to 1.19 cm(3)/g) can be obtained. The surface chemical properties of these ACs were investigated by X-ray photoelectron spectroscopy (XPS) and Boehm titration. Their textural and chemical characteristics were compared to those of an AC sample obtained by steam activation of vetiver roots. Classical molecules used for characterizing liquid phase adsorption, phenol and methylene blue (MB), were used. Adsorption kinetics of MB and phenol have been studied using commonly used kinetic models, i.e., the pseudo-first-order model, the pseudo-second-order model, the intraparticle diffusion model and as well the fractal, BWS (Brouers, Weron and Sotolongo) kinetic equation. The correlation coefficients (R(2)) and the normalized standard deviation Deltaq (%) were determined showing globally, that the recently derived fractal kinetic equation could best describe the adsorption kinetics for the adsorbates tested here, indicating a complex adsorption mechanism. The experimental adsorption isotherms of these molecules on the activated carbon were as well analysed using four isotherms: the classical Freundlich, Langmuir, Redlich-Peterson equations, but as well the newly published deformed Weibull Brouers-Sotolongo isotherm. The results obtained from the application of the equations show that the best fits were achieved with the Brouers-Sotolongo equation and with the Redlich-Peterson equation. Influence of surface functional groups towards MB adsorption is as well studied using various ACs prepared from vetiver roots and sugar cane bagasse. Opposite effects governing MB

  9. Preparation of TiC/W core–shell structured powders by one-step activation and chemical reduction process

    International Nuclear Information System (INIS)

    Ding, Xiao-Yu; Luo, Lai-Ma; Huang, Li-Mei; Luo, Guang-Nan; Zhu, Xiao-Yong; Cheng, Ji-Gui; Wu, Yu-Cheng

    2015-01-01

    Highlights: • A novel wet chemical method was used to prepare TiC/W core–shell structure powders. • TiC nanoparticles were well-encapsulated by W shells. • TiC phase was present in the interior of tungsten grains. - Abstract: In the present study, one-step activation and chemical reduction process as a novel wet-chemical route was performed for the preparation of TiC/W core–shell structured ultra-fine powders. The XRD, FE-SEM, TEM and EDS results demonstrated that the as-synthesized powders are of high purity and uniform with a diameter of approximately 500 nm. It is also found that the TiC nanoparticles were well-encapsulated by W shells. Such a unique process suggests a new method for preparing X/W (X refers the water-insoluble nanoparticles) core–shell nanoparticles with different cores

  10. Preparation and Determination of the Physical and Chemical Properties of Margarine

    Directory of Open Access Journals (Sweden)

    Habazin, S.

    2012-02-01

    Full Text Available Nutrition is one of the most basic needs of the human body. It ensures the introduction of substances needed to sustain life of the organism, its growth and proper development. In the food pyramid, fats together with carbohydrates are at the very top. One source of fat in human nutrition is margarine. Margarine comprises at least 82 % vegetable fats and 16 % water. The remainder consists of lecithin, sugar, salt, colours, and vitamins.The margarine production process involves hydrogenation of vegetable fats, assembling the margarine mixture, emulsifying, crystallization and packing.The objective of this study was to show that margarine could be prepared in a school laboratory under conditions that are applicable for such laboratory. Meaning:a In a school laboratory at normal pressure and at elevated temperature with nickel as catalyst, i.e. without the use of an autoclave, carry out the reaction of hydrogenation soybean and palm oil in order to obtain a vegetable fat that is the basic ingredient of margarine. During the preparation of margarine, the hydrogenation reaction was carefully monitored by determining the iodine value.b Preparation of margarine obtained from vegetable fats.c Determination and comparison of selected physical and chemical properties of the product with the same properties of several types of margarines available on the market. The following properties were determined:– Melting point, in order to obtain composition of fat phase and determine suitability for humanuse.– Acid value, as an indicator of the amount of free fatty acids that influence the taste.– Peroxide value, for insight into the oxidative stability of fats.This work has shown that it is possible to make vegetable fat in a school lab by hydrogenation of vegetable oils. Unlike the industrial process of hydrogenation carried out under a pressure of 0.36 to 2 atm, which takes about two hours, our reaction was carried out at atmospheric pressure but with a

  11. Preparation of industrial chemicals by acid leaching from the koga nepheline syenite, southern Swat, lesser Himalayas-Pakistan

    International Nuclear Information System (INIS)

    Nizami, A.R.

    2012-01-01

    This paper encompasses the study on the preparation of industrial chemicals by acid leaching from the Koga nepheline syenite, Southern Swat, Lesser Himalayas-Pakistan. These rocks have been studied in detail by many workers to exploit their industrial utility in the form of powdered rock material in glass and ceramics and steel industry. The present authors for the first time carried out acid leaching studies and prepared a number of industrial chemicals, like, alumina, aluminium sulphate, sodium and ammonium alums, sodium sulphate) and sodium bisulphate by simple chemical reactions at bench scale successfully. The developed process is simple and economically viable. It is recommended to exploit this process in cottage industry in the mountainous areas hosting these rocks for the benefit of local population. The research and development work for production of these chemicals at pilot plant and industrial scale is recommended as well. (author)

  12. Evaluating the residual stress in PbTiO3 thin films prepared by a polymeric chemical method

    International Nuclear Information System (INIS)

    Valim, D; Filho, A G Souza; Freire, P T C; Filho, J Mendes; Guarany, C A; Reis, R N; Araujo, E B

    2004-01-01

    We report a study of residual stress in PbTiO 3 (PT) thin films prepared on Si substrates by a polymeric chemical method. The E(1TO) frequency was used to evaluate the residual stress through an empirical equation available for bulk PT. We find that the residual stress in PT films increases as the film thickness decreases and conclude that it originates essentially from the contributions of extrinsic and intrinsic factors. Polarized Raman experiments showed that the PT films prepared by a polymeric chemical method are somewhat a-domain (polar axis c parallel to the substrate) oriented

  13. Identification of chemicals relevant to the Chemical Weapons Convention using the novel sample-preparation methods and strategies of the Mobile Laboratory of the Organization for the Prohibition of Chemical Weapons

    NARCIS (Netherlands)

    Terzic, O.; Gregg, H.; de Voogt, P.

    2015-01-01

    The standard approach to on-site sample preparation for gas chromatography-mass spectrometry analysis of chemicals relevant to the Chemical Weapons Convention provides relatively good coverage of the target analytes, but it suffers from a number of drawbacks, such as low sample throughput, use of

  14. 1,5-Anhydro-D-fructose: biocatalytic and chemical synthetic methods for the preparation, transformation and derivatization

    DEFF Research Database (Denmark)

    Lundt, Inge; Yu, Shukun

    2010-01-01

    1,5-Anhydro-D-fructose (1,5AnFru) is a monoketosaccharide that can be prepared enzymatically from starch by a-1,4-glucan lyase or chemically from D-glucose or D-fructose in a few steps with high yields. The formed 1,5AnFru can be derivatized both enzymatically and chemically to interesting new...

  15. YBa2Cu3O7-x thin films prepared by chemical solution deposition

    International Nuclear Information System (INIS)

    Apetrii, Claudia

    2009-01-01

    The discovery of superconductivity in ceramic materials by Bednorz and Mueller in early 1987, immediately followed by Wu et al., who showed that YBa 2 Cu 3 O 7-x (YBCO) becomes superconducting (92 K) well above the boiling point of nitrogen (77 K) created a great excitement in superconductivity research. Potential applications of high T c -superconductors require large critical currents and high-applied magnetic fields. Effective ways to increase the critical current density at high magnetic fields in YBCO are the introduction of nanoparticles and chemical substitution of yttrium by other rare earth elements. Since low costs and environmental compatibility are essential conditions for the preparation of long length YBCO films, the cost effective chemical solution deposition (CSD) procedure was selected, given that no vacuum technology is required. To reveal the flexibility and the good optimization possibilities of the CSD approach two main processes were chosen for comparison: a fluorine-free method, namely the polymer-metal precursor technique, and a fluorine-based method, the metalorganic deposition (MOD) using the trifluoroacetates (TFA) technique. Sharp transition temperature widths ΔT c of 1.1 K for the polymer metal method, 0.8 K for TFA method and critical current densities J c of ∼3.5 MA/cm 2 shows that high quality YBCO thin films can be produced using both techniques. Especially interesting is the magnetic field dependence of the critical current density J c (B) of the Y(Dy)BCO (80 %) films showing that for the lower magnetic fields the critical current density J c (B) is higher for a standard YBCO film, but at fields higher than 4.5 T the critical current density J c (B) of Y(Dy)BCO is larger than that for the YBCO. Above 8 T, J c (B) of the Y(Dy)BCO film is more than one order of magnitude higher than in pure YBCO film. (orig.)

  16. Effect of gamma irradiation on microbial load, chemical and sensory properties of locally prepared fast meal

    International Nuclear Information System (INIS)

    Al-Bachir, M.

    2006-12-01

    Locally prepared meal (Kubba, Borak, Cheese borak and Sheesh Tawoq) was treated with 0, 2, 4, or 6 kGy doses of gamma irradiation. treated and untreated samples were kept in a refrigerators (1- 4 centigrade degree). Microbiological and chemical analyses were performed on each treated sample immediately after processing, and weekly throughout storage period which lasted for 3 weeks for Kubba, 6 weeks for Borak and Cheese Borak and 20 weeks for Sheesh Tawoq. Sensory evaluation and proximate analysis were done within one week after irradiation. Results of the proximate analysis of Borak, Cheese Borak and Sheesh Tawoq showed that irradiation doses did not have a significant effect on moisture, protein and fat content of meals. Whereas, irradiation decreased the major constituents of Kubba moisture, protein and fats. Used doses of gamma irradiation decreased the microorganisms load and increased the shelf-life of Kubba, Borak, Cheese Borak and Sheesh Tawoq. The radiation doses required to reduce the microorganisms load one log cycle (D 1 0) in Borak were 456 and 510 Gy and in cheese Borak 303 and 500 Gy for the Salmonella and E. coli respectively. The three chemical parameters, total acidity, lipid peroxide and volatile basic nitrogen, which were chosen as the indices of freshness, were all well within the acceptable limit for up to 3 weeks for Kubba, 6 weeks for Borak and Cheese Borak and 20 weeks for Sheesh Tawoq treated with 6 kGy. Sensory evaluation showed no significant differences between irradiated and non-irradiated samples. (author)

  17. The chemical and catalytic properties of nanocrystalline metal oxides prepared through modified sol-gel synthesis

    Science.gov (United States)

    Carnes, Corrie Leigh

    The goal of this research was to synthesize, characterize and study the chemical properties of nanocrystalline metal oxides. Nanocrystalline (NC) ZnO, CuO, NiO, Al2O3, and the binary Al2O 3/MgO and ZnO/CuO were prepared through modified sol gel methods. These NC metal oxides were studied in comparison to the commercial (CM) metal oxides. The samples were characterized by XRD, TGA, FTIR, BET, and TEM. The NC samples were all accompanied by a significant increase in surface area and decrease in crystallite size. Several chemical reactions were studied to compare the NC samples to the CM samples. One of the reactions involved a high temperature reaction between carbon tetrachloride and the oxide to form carbon dioxide and the corresponding metal chloride. A similar high temperature reaction was conducted between the metal oxide and hydrogen sulfide to form water and the corresponding metal sulfide. A room temperature gas phase adsorption was studied where SO2 was adsorbed onto the oxide. A liquid phase adsorption conducted at room temperature was the destructive adsorption of paraoxon (a toxic insecticide). In all reactions the NC samples exhibited greater activity, destroying or adsorbing a larger amount of the toxins compared to the CM samples. To better study surface area effects catalytic reactions were also studied. The catalysis of methanol was studied over the nanocrystalline ZnO, CuO, NiO, and ZnO/CuO samples in comparison to their commercial counterparts. In most cases the NC samples proved to be more active catalysts, having higher percent conversions and turnover numbers. A second catalytic reaction was also studied, this reaction was investigated to look at the support effects. The catalysis of cyclopropane to propane was studied over Pt and Co catalysts. These catalysts were supported onto NC and CM alumina by impregnation. By observing differences in the catalytic behavior, support effects have become apparent.

  18. Preparation, chemical composition and storage studies of quamachil (Pithecellobium dulce L.) aril powder.

    Science.gov (United States)

    Rao, Galla Narsing; Nagender, Allani; Satyanarayana, Akula; Rao, Dubasi Govardhana

    2011-02-01

    Quamachil aril powder samples were prepared and evaluated for chemical composition and sensory quality by packing in two packaging systems during storage for six months. The protein contents were 12.4 and 15.0% in white and pink aril powders respectively. The titrable acidity of white and pink aril powders were 2.4 and 4.8% respectively. Ca and Fe contents in white aril powder samples were 60 and 12 mg/100 g where as in pink aril powder 62 and 16 mg/100 g, respectively. The anthocyanin content in pink powder decreased from 50.5 to 11.2 and 14.1 mg/100 g in samples packed in polyethylene (PE) and metalised polyester polyethylene laminated pouches respectively. Total polyphenol amount increased in both the powders irrespective of packaging material. Sorption isotherms indicated that both white and pink aril powders were hygroscopic and equilibrated at low relative humidity of 28 and 32%, respectively.

  19. Chemical preparation of biological materials for accurate chromium determination by isotope dilution mass spectrometry

    International Nuclear Information System (INIS)

    Dunstan, L.P.; Garner, E.L.

    1977-01-01

    The current interest in trace elements in biological materials has created a need for accurate methods of analysis. The source of discrepancies and variations in chromium concentration determinations is often traceable to inadequate methods of sample preparation. Any method of Cr analysis that requires acid digestion of a biological matrix must take into consideration the existence or formation of a volatile Cr component. In addition, because Cr is often present at concentrations less than 1 μg/g, the analytical blank becomes a potential source of error. Chemical procedures have been developed for the digestion of the biological matrix and the separation of Cr without either large analytical blanks or significant losses by volatilization. These procedures have been used for the analysis of NBS Standard Reference Material (SRM) 1569 Brewers Yeast; SRM 1577 Bovine Liver; SRM 1570 Spinach and other biological materials including human hair and nails. At this time, samples containing 1 μg of Cr can be determined with an estimated accuracy of 2 percent

  20. Preparation and structure of porous dielectrics by plasma enhanced chemical vapor deposition

    International Nuclear Information System (INIS)

    Gates, S. M.; Neumayer, D. A.; Sherwood, M. H.; Grill, A.; Wang, X.; Sankarapandian, M.

    2007-01-01

    The preparation of ultralow dielectric constant porous silicon, carbon, oxygen, hydrogen alloy dielectrics, called 'pSiCOH', using a production 200 mm plasma enhanced chemical vapor deposition tool and a thermal treatment is reported here. The effect of deposition temperature on the pSiCOH film is examined using Fourier transform infrared (FTIR) spectroscopy, dielectric constant (k), and film shrinkage measurements. For all deposition temperatures, carbon in the final porous film is shown to be predominantly Si-CH 3 species, and lower k is shown to correlate with increased concentration of Si-CH 3 . NMR and FTIR spectroscopies clearly detect the loss of a removable, unstable, hydrocarbon (CH x ) phase during the thermal treatment. Also detected are increased cross-linking of the Si-O skeleton, and concentration changes for three distinct structures of carbon. In the as deposited films, deposition temperature also affects the hydrocarbon (CH x ) content and the presence of C=O and C=C functional groups

  1. Preparation and physico-chemical properties of hydrogels from carboxymethyl cassava starch crosslinked with citric acid

    Science.gov (United States)

    Boonkham, Sasikan; Sangseethong, Kunruedee; Chatakanon, Pathama; Niamnuy, Chalida; Nakasaki, Kiyohiko; Sriroth, Klanarong

    2014-06-01

    Recently, environmentally friendly hydrogels prepared from renewable bio-based resources have drawn significant attention from both industrial and academic sectors. In this study, chemically crosslinked hydrogels have been developed from cassava starch which is a bio-based polymer using a non-toxic citric acid as a crosslinking agent. Cassava starch was first modified by carboxymethylation to improve its water absorbency property. The carboxymethyl cassava starch (CMCS) obtained was then crosslinked with citric acid at different concentrations and reaction times. The gel fraction of hydrogels increased progressively with increasing citric acid concentration. Free swelling capacity of hydrogels in de-ionized water, saline solution and buffers at various pHs as well as absorption under load were investigated. The results revealed that swelling behavior and mechanical characteristic of hydrogels depended on the citric acid concentration used in reaction. Increasing citric acid concentration resulted in hydrogels with stronger network but lower swelling and absorption capacity. The cassava starch hydrogels developed were sensitive to ionic strength and pH of surrounding medium, showing much reduced swelling capacity in saline salt solution and acidic buffers.

  2. Low-cost plasmonic solar cells prepared by chemical spray pyrolysis

    Directory of Open Access Journals (Sweden)

    Erki Kärber

    2014-12-01

    Full Text Available Solar cells consisting of an extremely thin In2S3/CuInS2 buffer/absorber layer uniformly covering planar ZnO were prepared entirely by chemical spray pyrolysis. Au nanoparticles (Au-NPs were formed via thermal decomposition of a gold(III chloride trihydrate (HAuCl4·3H2O precursor by spraying 2 mmol/L of the aqueous precursor solution onto a substrate held at 260 °C. Current–voltage scans and external quantum efficiency spectra were used to evaluate the solar cell performance. This work investigates the effect of the location of the Au-NP layer deposition (front side vs rear side in the solar cell and the effect of varying the volume (2.5–10 mL of the sprayed Au precursor solution. A 63% increase (from 4.6 to 7.5 mA/cm2 of the short-circuit current density was observed when 2.5 mL of the precursor solution was deposited onto the rear side of the solar cell.

  3. Pine growth and plant community response to chemical vs. mechanical site preparation for establishing loblolly and slash pine

    Science.gov (United States)

    James H. Miller; Zhijuan Qiu

    1995-01-01

    Chemical and mechanical site preparation methods were studied for establishing loblolly (Pinus taeda L) and slash (P. elliottii var. elliottii Engelm.) pine following both integrated fuelwood-pulpwood harvesting and conventional whole-tree harvesting of pines and hardwoods in southem Alabama's Middle Coastal...

  4. A comparison of properties between carboxylated acrylic rubbers prepared by γ-ray irradiation and chemical method

    International Nuclear Information System (INIS)

    Wang Weiwei; Chang Zhenqi; Wang Mozhen; Zhang Zhicheng; Lv Pin

    2006-01-01

    Acrylic rubbers (ACM) carboxylated by acrylic acid or itaconic acid were prepared by 60 Co γ-ray or chemical-initiator (K 2 S 2 O 8 ) induced emulsion copolymerization. The polymers were characterized by Fourier transform infrared spectroscopy (FT-IR). Acid value, molecular weight and polydispersity index (PDI) of the polymers were determined by non-aqueous titration method and gel permeation chromatography (GPC), respectively. Vulcanization and mechanical properties of the filled ACM were studied by rheometric measurement, gel fraction analysis, mechanical property tests and dynamic mechanical thermal analysis (DMTA). The results show that the ACMs prepared by γ-ray irradiation have lower acid value, higher molecular weight and narrower PDI than chemically prepared ACMs of the same compositions. The itaconic acid carboxylated ACM has better cure characteristics and mechanical properties than the acrylic acid carboxylated ACM. The itaconic acid carboxylated ACM prepared by γ-ray irradiation has higher gel fraction and better cure characteristics as well as mechanical properties than that prepared by chemical method. (authors)

  5. Ethnopharmacological and Chemical Characterization of Salvia Species Used in Valencian Traditional Herbal Preparations

    Directory of Open Access Journals (Sweden)

    Vanessa Martínez-Francés

    2017-07-01

    Full Text Available In Valencia Region (Spain, some wild and cultivated sages are used for medicinal purposes. Among them, Salvia officinalis subsp. lavandulifolia (SL is widely employed and known for production of Spanish sage oil and herbal products. Nevertheless, it shares the market with S. blancoana subsp. mariolensis (SB and, to a lesser extent, with their hybrid S. x hegelmaieri (SH. The knowledge on these two species is far low and confusion between them is possible. The aim of the present paper is to improve the ethnopharmacological, morphological and chemical knowledge of these sages, and to contribute to setting up quality specifications for improving identification and distinction from other Salvia species, such as, S. officinalis subsp. officinalis, S. x auriculata and S. microphylla var. microphylla. Samples were collected in Valencia Region and surrounding mountain areas during the ethnopharmacological field work. Twenty-nine medicinal uses were reported for SL, 13 of them being also recorded for SB. Of particular interest is a homemade liquor, used as digestive and known as “salvieta,” which is mainly prepared with SB. The macro- and microscopic characters are insufficient for identification of cut, crushed or powdered material. The study of the essential oil and a HPTLC (High Performance Thin Layer Chromatography fingerprint of their extracts could help to distinguish SB from the other sages. The essential oil from dried aerial parts of SB (content: 1.8–4.5% was characterized by GC-FID (Gas Chromatography with Flame Ionization Detector and GC-MS (Gas Chromatography coupled to Mass Spectrometry showing a composition close to that currently accepted for Spanish sage essential oil in the European Pharmacopoeia, ISO (International Standard Organization and UNE (Una Norma Española standards, with 1,8-cineole (13.7–45.7% and camphor (12.1–28.6% as major constituents. HPTLC methods, based on the analysis of hydroalcoholic and dichloromethane

  6. Preparing for chemical terrorism: a study of the stability of expired pralidoxime (2-PAM).

    Science.gov (United States)

    Hoffman, Robert S; Mercurio-Zappala, Maria; Bouchard, Nicole; Ravikumar, Padinjarekuttu; Goldfrank, Lewis

    2012-03-01

    Oximes such as pralidoxime (2-PAM) are essential antidotes for life-threatening organophosphate poisoning. Unfortunately, oximes are expensive, have limited use, and have short shelf lives. As such, maintaining large stockpiles in preparation for terrorist activity is not always possible. We have demonstrated that atropine is stable well beyond its labeled shelf life and that recently expired 2-PAM was clinically efficacious in a series of poisoned patients. Because 2-PAM is often dosed empirically, clinical improvement does not guarantee pharmacological stability. We therefore chose to analyze the chemical stability of expired 2-PAM. Samples of lyophylized 2-PAM were maintained according to the manufacturer's recommendations for 20 years beyond the published shelf life. We studied 2-PAM contained in a MARK I autoinjector that was stored properly for 3 years beyond its expiration date. An Agilent LC/MSD 1100 with diode-array detector and an Agilent Sorbax SB-C-18, 4.6 × 150-mm, 5-μm column were used with the following solvent systems: water with 0.01% trifluoroacetic acid and methanol with 0.01% trifluoroacetic acid. Fresh reagent grade 2-PAM was used as a standard. Results were repeated for consistency. Lyophylized 2-PAM was a white powder that was clear and colorless in solution. Liquid chromatography was identical to the standard and resulted in 2 isolated peaks with identical mass spectra, suggesting that they are stereoisomers. The autoinjector discharged a clear, yellowish solution. In addition to the 2 peaks identified for lyophylized 2-PAM, a small third peak was identified with a mass spectra corresponding to the reported N -methyl pyridinium carboxaldehyde degradation product. When properly stored, lyophylized 2-PAM appears to be chemically stable well beyond its expiration date. Although the relative amount of degradation product found in solubilized (autoinjector) 2-PAM was small, it is unclear whether this may be toxic and therefore is of concern

  7. Extended phase homogeneity and electrical properties of barium calcium titanate prepared by the wet chemical methods

    International Nuclear Information System (INIS)

    Jayanthi, S.; Kutty, T.R.N.

    2004-01-01

    Ca-substituted BaTiO 3 with extended homogeneity range upto ∼50 mol% CaTiO 3 have been prepared by three different chemical routes namely carbonate-oxalate (COBCT), gel-carbonate (GCBCT), and gel-to-crystallite conversion (GHBCT) followed by heat treatment above 1150 deg. C. X-ray powder diffraction (XRD) data show continuous decrease in the tetragonal unit cell parameters as well as c 0 /a 0 ratio with CaTiO 3 content, which are in accordance with the substitution of smaller sized Ca 2+ ions at the barium sites. The microstructure as well as the dielectric properties are greatly influenced by the cationic ratio, α=(Ba+Ca)/Ti. The grain size decreases with CaTiO 3 content for the stoichiometric samples (α=1), whereas ultrafine microstructure is observed in the case of off-stoichiometric samples (α>1) for the whole compositional range of CaTiO 3 concentrations. Sharper ε r -T characteristics at lower calcium content and broader ε r -T with decreased ε max , in the higher calcium range are observed in the case of α=1. Whereas nanometer grained ceramics exhibiting diffuse ε r -T characteristics are obtained in the case of α>1. The positive temperature coefficient of resistivity (PTCR) is realized for barium calcium titanate ceramics having 0.3 at.% Sb as the donor dopant for higher CaTiO 3 (typically 30 mol%) containing samples (α=1), indicating that Ca 2+ ions do not behave as acceptors if they were to substitute at the Ti 4+ sites. Whereas the off-stoichiometric (α>1) ceramics retained high resistivity, indicative of the Ti-site occupancy for Ca 2+ in fine grain ceramics

  8. High coercivity Gd-substituted Ba hexaferrites, prepared by chemical coprecipitation

    Science.gov (United States)

    Litsardakis, G.; Manolakis, I.; Serletis, C.; Efthimiadis, K. G.

    2008-04-01

    A series of Gd-substituted Ba hexaferrites with nominal formula (Ba1-xGdx)Oṡ5.25 Fe2O3 (x=0-0.30) were prepared by the chemical coprecipitation method from nitrate precursors and heating at T =800-1200°C for 2h. The samples have been examined by x-ray diffraction, vibrating-sample magnetometer, and scanning electron microscopy methods. Gd substituted samples form single phase materials with the M-type hexaferrite structure at all heating temperatures, in the range of x ⩽0.10-0.20. The saturation magnetization (at 1.8T) varies slightly with x in most cases and, for x =0.05-0.10, it increases up to 66.7Am2/kg, exceeding the value of the unsubstituted hexaferrite. A strong enhancement of the coercivity is observed for all substituted samples, with maximum values Hc=457kA/m for the single-phase x =0.10 sample annealed at 1000°C and Hc=477kA/m for the x =0.25 sample annealed at 1100°C which contains Fe2O3 and GdFeO3 impurities. As the variation of coercivity with either substitution rate (x ) or annealing temperature is not monotonic, three different factors may account for the high coercivities that are obtained: (a) an inhibition of grain growth due to the presence of Gd, (b) a possible inherent effect on magnetocrystalline anisotropy, especially for single phase samples, and (c) a microstructural effect of secondary phases.

  9. Enhanced local piezoelectric response in the erbium-doped ZnO nanostructures prepared by wet chemical synthesis

    Directory of Open Access Journals (Sweden)

    Reza Zamiri

    2017-03-01

    Full Text Available Pure and erbium (Er doped ZnO nanostructures were prepared by simple and cost effective wet chemical precipitation method. The successful doping with phase purity of prepared ZnO nanostructure was confirmed by X-ray diffraction (XRD and their Rietveld analysis. The change in structural morphology of nanoscale features of prepared ZnO nanopowders on Er doping was observed from their scanning electron microscopy (SEM images. The presence of Er in prepared ZnO nanopowder was further confirmed from corresponding energy dispersive X-ray spectroscopy (EDX spectra of scanned SEM images. Piezoelectric properties of before (green samples and after sintering of consolidated compact of synthesized nanopowders were successfully measured. The out-of-plane (effective longitudinal and in-plane (effective shear coefficients of the samples were estimated from the local piezoresponse.

  10. Preparation and chemical characteristics of Karunguruvai Khadi used in the traditional Siddha formulation of herbo-mineral-based medicine

    Directory of Open Access Journals (Sweden)

    Eleza Chellakkan

    2016-01-01

    Conclusion: The result of the chemical analysis of Khadi extracts showed that Khadi prepared from the Karunguruvai paddy grains (rice was the best base solvent for ion exchange in the preparation of muppu than Samba Khadi. The analysis of the composition of these two types of Karunguruvai Khadi show that it is a good solvent for the elimination of heavy metals and for the enrichment of elements in Pooneeru powder (muppu, the chuurnam of Siddha drugs. These characteristics enhance the therapeutic potential and safety of the drugs for healing chronic diseases.

  11. Physical-chemical and biological characterization of different preparations of equine chorionic gonadotropin

    OpenAIRE

    Alvarez, Rafael Herrera; Natal, Fabio Luis Nogueira; Ribela, Maria Teresa Carvalho Pinto; de Almeida, Beatriz Elane; de Oliveira, Jo?o Ezequiel; Bartolini, Paolo

    2016-01-01

    Ovarian stimulation with commercial preparations of equine chorionic gonadotropin (eCG) produces extremely variable responses in domestic animals, ranging from excessive stimulation to practically no stimulation, when applied on the basis of their declared unitage. This study was conducted to analyze four commercial preparations from different manufacturers via reversed-phase HPLC (RP-HPLC) in comparison with a reference preparation and an official International Standard from the World Health...

  12. Hydrogen evolution under visible light over LaCoO3 prepared by chemical route

    International Nuclear Information System (INIS)

    Meziani, D.; Reziga, A.; Rekhila, G.; Bellal, B.; Trari, M.

    2014-01-01

    Highlights: • Visible-light hydrogen evolution is achieved on the hetero-system LaCoO 3 /SnO 2 . • The crystal field splits the Co 3+ : 3d orbital by a value of 2.05 eV. • The capacitance plot shows p-type conduction with flat band potential of 0 V SCE. • The photo-electrochemistry yields a valence and conduction bands of 3d parentage. - Abstract: The semiconducting properties of the perovskite LaCoO 3 , prepared by nitrate route, are investigated for the first time by the photo-electrochemical technique. The oxide shows a direct optical transition at 1.33 eV, due to Co 3+ : 3d orbital splitting in octahedral site and possesses a chemical stability over a fair pH range (4–14). The conductivity follows an exponential type law with a hole mobility (8.3 × 10 −2 cm 2 V −1 s −1 ), thermally activated. The Mott–Schottky plot in KOH medium is characteristic of p type conduction with a flat band potential of 0 V SCE and a holes density of 1.35 × 10 17 cm −3 . The electrochemical impedance spectroscopy reveals the predominance of the bulk and grains boundaries contributions with a constant phase element and a multi-relaxation type nature. As application, the hydrogen evolution upon visible light is demonstrated on the hetero-junction LaCoO 3 /SnO 2 . The best performance occurs at pH ∼ 12.8 with an evolution rate of 0.25 cm 3 min −1 (mg LaCoO 3 ) −1 and a quantum yield of 0.11%. The improved activity is attributed to the wide depletion width of ∼10 nm and the potential of the conduction band of LaCoO 3 (−1.34 V SCE ), more negative than that of SnO 2 , the latter acts as electrons bridge for the interfacial water reduction. The relevance of 3d orbital of the performance of semi conducting photoelectrode is discussed

  13. Characterizations on the microstructures of LiMn2O4 prepared by a simple soft-chemical technique

    International Nuclear Information System (INIS)

    Wei Yingjin; Kim, Kwang Bum; Chen Gang; Park, Chul W.

    2008-01-01

    LiMn 2 O 4 powders were prepared by a simple soft-chemical technique at different temperatures. X-ray diffraction and thermogravimetric analysis suggested that the material prepared at 800 deg. C was stoichiometric LiMn 2 O 4 , whereas those prepared at 600 and 700 deg. C were Li[Mn 0.77 3+ Mn 1.23 4+ ]O 4.115 and Li[Mn 0.85 3+ Mn 1.15 4+ ]O 4.075 . Several typical XRD peaks of the compounds were investigated with an aim to elucidate (i) the Li immigration to the 16d octahedral sites, (ii) the partial tetragonal phase transition of the material and (iii) the mean coherent domain size and microstrain. SEM study showed that the particle size of the materials increased with heating temperature. The activation energy for the material particle growth was determined as 30.4 kJ mol -1

  14. Final status report in preparation for the chemical cleaning of Dresden-1, DNS-D1-034

    International Nuclear Information System (INIS)

    1981-09-01

    This report discusses the status of all of the activities conducted in preparation for the chemical cleaning of the Dresden-1 Nuclear Power Plant of Commonwealth Edison of Illinois. The metallurgical testing of a solvent and its ability to remove radioactivity are reviewed. Included are all engineering details relating to the modifications to the primary system to be able to perform the chemical cleaning and to rinse the cleaning solvent out of the equipment. A facility to store and process spent cleaning solutions is described in detail. Construction activities and preoperational activities are recounted. Licensing activities, quality assurance, safety, and radiation protection are discussed. The report includes recommendations for future actions for restarting the project when approval is received. All of the efforts discussed in this Final Status Report led to the conclusion that the chemical cleaning, as planned, was feasible. All of the necessary modifications and new equipment are in place and are operational

  15. Chemical Peels

    Science.gov (United States)

    ... care Kids’ zone Video library Find a dermatologist Chemical peels Overview Chemical peels: Overview Also called chemexfoliation , derma peeling Do ... Overview Chemical peels: FAQs Chemical peels: Preparation FAQs Chemical peels: FAQs To help you decide whether this ...

  16. Preparation and chemical crystallographic study of new hydrides and hydro-fluorides of ionic character; Preparation et etude cristallochimique de nouveaux hydrures et fluorohydrures a caractere ionique

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hyung-Ho

    1988-07-22

    Within the context of a growing interest in the study of reversible hydrides with the perspective of their application in hydrogen storage, this research thesis more particularly addressed the case of ternary hydrides and fluorides, and of hydro-fluorides. The author reports the development of a method of preparation of alkaline hydrides, of alkaline earth hydrides and of europium hydride, and then the elaboration of ternary hydrides. He addresses the preparation of caesium fluorides and of calcium or nickel fluorides, of Europium fluorides, and of ternary fluorides. Then, he addresses the preparation of hydro-fluorides (caesium, calcium, europium fluorides, and caesium and nickel fluorides). The author presents the various experimental techniques: chemical analysis, radio-crystallographic analysis, volumetric mass density measurement, magnetic measurements, ionic conductivity measurements, Moessbauer spectroscopy, and nuclear magnetic resonance. He reports the crystallographic study of some ternary alkaline and alkaline-earth hydrides (KH-MgH{sub 2}, RbH-CaH{sub 2}, CsH-CaH{sub 2}, RbH-MgH{sub 2} and CsH-MgH{sub 2}) and of some hydro-fluorides (CsCaF{sub 2}H, EuF{sub 2}H, CsNiF{sub 2}H) [French] Dans une premiere partie, de nouveaux hydrures ternaires ont ete prepares et caracterises. Les systemes etudies sont AH-MH 2 (A = K, Rb, Cs et M = Mg, Ca). Dans les systemes AH-MgH 2 l'evolution structurale a ete discutee en fonction du caractere iono-covalent de la liaison magnesium-hydrogene. Dans une deuxieme partie, plusieurs nouveaux fluorohydrures ont ete mis en evidence. L'effet de la substitution de l'hydrogene au fluor dans ces phases a ete etudiee en utilisant la RMN, la spectroscopie Moessbauer, la conductivite ionique et les mesures magnetiques.

  17. Microstructures, Mechanical Properties and Thermal Conductivities of W-0.5 wt.%TiC Alloys Prepared via Ball Milling and Wet Chemical Method

    Science.gov (United States)

    Lang, Shaoting; Yan, Qingzhi; Sun, Ningbo; Zhang, Xiaoxin; Ge, Changchun

    2017-10-01

    Two kinds of W-0.5 wt.%TiC alloys were prepared, one by ball milling and the other by the wet chemical method. For comparison, pure tungsten powders were chemically prepared and sintered by the same process. The microstructures, mechanical properties and thermal conductivities of the prepared samples were characterized. It has been found that the wet chemical method resulted in finer sizes and more uniform distribution of TiC particles in the sintered tungsten matrix than the ball milling method. The W-TiC alloy prepared by the wet chemical method achieved the highest bending strength (1065.72 MPa) among the samples. Further, it also exhibited obviously higher thermal conductivities in the temperature range of room temperature to 600°C than did the W-TiC alloy prepared by ball milling, but the differences in their thermal conductivities could be ignored in the range of 600-800°C.

  18. Chemical Weapons: FEMA and Army Must Be Proactive in Preparing States for Emergencies

    National Research Council Canada - National Science Library

    2001-01-01

    .... Such an accident could affect people in 10 different states. The Army plans to destroy its entire chemical weapons stockpile by 2007 and is taking measures to protect the public before and during the demilitarization process...

  19. 78 FR 4446 - Exempt Chemical Preparations Under the Controlled Substances Act

    Science.gov (United States)

    2013-01-22

    ... TOXI-LAB DISCS LTD HD Plastic vial: 50 discs... 12/22/2011 Agilent Technologies TOXI-LAB DISCS LTD OP... Chemicals, Inc... (+)-iodo-Lysergic Acid Vial: 1 mL 12/22/2011 diethylamide [125I]. American Radiolabeled.../2011 (1 mg/mL). American Radiolabeled Chemicals, Inc... Lysergic Acid (1 mg/mL)........ Vial: 1 mL 12...

  20. Analysis of the Si(111) surface prepared in chemical vapor ambient for subsequent III-V heteroepitaxy

    International Nuclear Information System (INIS)

    Zhao, W.; Steidl, M.; Paszuk, A.; Brückner, S.; Dobrich, A.; Supplie, O.; Kleinschmidt, P.; Hannappel, T.

    2017-01-01

    Highlights: • We investigate the Si(111) surface prepared in CVD ambient at 1000 °C in 950 mbar H_2. • UHV-based XPS, LEED, STM and FTIR as well as ambient AFM are applied. • After processing the Si(111) surface is free of contamination and atomically flat. • The surface exhibits a (1 × 1) reconstruction and monohydride termination. • Wet-chemical pretreatment and homoepitaxy are required for a regular step structure. - Abstract: For well-defined heteroepitaxial growth of III-V epilayers on Si(111) substrates the atomic structure of the silicon surface is an essential element. Here, we study the preparation of the Si(111) surface in H_2-based chemical vapor ambient as well as its atomic structure after contamination-free transfer to ultrahigh vacuum (UHV). Applying complementary UHV-based techniques, we derive a complete picture of the atomic surface structure and its chemical composition. X-ray photoelectron spectroscopy measurements after high-temperature annealing confirm a Si surface free of any traces of oxygen or other impurities. The annealing in H_2 ambient leads to a monohydride surface termination, as verified by Fourier-transform infrared spectroscopy. Scanning tunneling microscopy confirms a well ordered, atomically smooth surface, which is (1 × 1) reconstructed, in agreement with low energy electron diffraction patterns. Atomic force microscopy reveals a significant influence of homoepitaxy and wet-chemical pretreatment on the surface morphology. Our findings show that wet-chemical pretreatment followed by high-temperature annealing leads to contamination-free, atomically flat Si(111) surfaces, which are ideally suited for subsequent III-V heteroepitaxy.

  1. Analysis of the Si(111) surface prepared in chemical vapor ambient for subsequent III-V heteroepitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, W.; Steidl, M.; Paszuk, A. [Technische Universität Ilmenau, Institut für Physik, 98693 Ilmenau (Germany); Brückner, S. [Technische Universität Ilmenau, Institut für Physik, 98693 Ilmenau (Germany); Helmholtz-Zentrum Berlin, Institut für Solare Brennstoffe, 14109 Berlin (Germany); Dobrich, A. [Technische Universität Ilmenau, Institut für Physik, 98693 Ilmenau (Germany); Supplie, O. [Technische Universität Ilmenau, Institut für Physik, 98693 Ilmenau (Germany); Helmholtz-Zentrum Berlin, Institut für Solare Brennstoffe, 14109 Berlin (Germany); Kleinschmidt, P. [Technische Universität Ilmenau, Institut für Physik, 98693 Ilmenau (Germany); Hannappel, T., E-mail: thomas.hannappel@tu-ilmenau.de [Technische Universität Ilmenau, Institut für Physik, 98693 Ilmenau (Germany); Helmholtz-Zentrum Berlin, Institut für Solare Brennstoffe, 14109 Berlin (Germany)

    2017-01-15

    Highlights: • We investigate the Si(111) surface prepared in CVD ambient at 1000 °C in 950 mbar H{sub 2}. • UHV-based XPS, LEED, STM and FTIR as well as ambient AFM are applied. • After processing the Si(111) surface is free of contamination and atomically flat. • The surface exhibits a (1 × 1) reconstruction and monohydride termination. • Wet-chemical pretreatment and homoepitaxy are required for a regular step structure. - Abstract: For well-defined heteroepitaxial growth of III-V epilayers on Si(111) substrates the atomic structure of the silicon surface is an essential element. Here, we study the preparation of the Si(111) surface in H{sub 2}-based chemical vapor ambient as well as its atomic structure after contamination-free transfer to ultrahigh vacuum (UHV). Applying complementary UHV-based techniques, we derive a complete picture of the atomic surface structure and its chemical composition. X-ray photoelectron spectroscopy measurements after high-temperature annealing confirm a Si surface free of any traces of oxygen or other impurities. The annealing in H{sub 2} ambient leads to a monohydride surface termination, as verified by Fourier-transform infrared spectroscopy. Scanning tunneling microscopy confirms a well ordered, atomically smooth surface, which is (1 × 1) reconstructed, in agreement with low energy electron diffraction patterns. Atomic force microscopy reveals a significant influence of homoepitaxy and wet-chemical pretreatment on the surface morphology. Our findings show that wet-chemical pretreatment followed by high-temperature annealing leads to contamination-free, atomically flat Si(111) surfaces, which are ideally suited for subsequent III-V heteroepitaxy.

  2. Physical-chemical and biocatalytic properties of a proteolytic complex of the preparation "Protepsin"

    Directory of Open Access Journals (Sweden)

    L. V. Antipova

    2016-01-01

    Full Text Available Enzymatic technologies were included strongly into practical activities of the person, the volume of the world market constantly grows and is updated. However the domestic production of enzymatic preparations very lags behind world level that is in many respects connected with insufficient scientific and technical base for a wide circulation of technologies in large-scale production. At the same time there were Russian producers of enzymatic preparations from animal fabrics and bodies for processing of raw materials of an animal origin, according to forecasts, of interest in rational use of resources of an animal origin. In article data on research of properties of the enzymatic preparation "Protepsin" and an assessment of prospects of application are provided in processing of raw materials of an animal origin. The enzymatic preparation "Protepsin" made in the conditions of JSC Plant of Endocrine Enzymes (Rzhavki, Moscow region activity at action on proteins of meat shows, including the strengthened structure, has milk-clotting effect, is active in the field of pH 4,0-6,0 and temperature 20-45zs. The proteinaceous complex includes 4 fractions, 2 from which possess the general proteolytic activity. One of them shows the general proteolytic and milk-clotting activity. Enzymes differ in an amino-acid set and molecular weight. The method of a disk electrophoresis determined molecular-mass structure of "Protepsin". The preparation inactivation conditions guaranteeing its safety in the production technology of foodstuff as active proteolytic enzymes in the course of digestion can cause violations of integrity of fabrics and corresponding diseases are shown. Thus, conditions of use of a perspective proteolytic preparation in technology of a wide range of food of an animal origin are in a complex proved and picked up.

  3. Magnetically assisted chemical separation (MACS) process: Preparation and optimization of particles for removal of transuranic elements

    International Nuclear Information System (INIS)

    Nunez, L.; Kaminski, M.; Bradley, C.; Buchholz, B.A.; Aase, S.B.; Tuazon, H.E.; Vandegrift, G.F.; Landsberger, S.

    1995-05-01

    The Magnetically Assisted Chemical Separation (MACS) process combines the selectivity afforded by solvent extractants with magnetic separation by using specially coated magnetic particles to provide a more efficient chemical separation of transuranic (TRU) elements, other radionuclides, and heavy metals from waste streams. Development of the MACS process uses chemical and physical techniques to elucidate the properties of particle coatings and the extent of radiolytic and chemical damage to the particles, and to optimize the stages of loading, extraction, and particle regeneration. This report describes the development of a separation process for TRU elements from various high-level waste streams. Polymer-coated ferromagnetic particles with an adsorbed layer of octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) diluted with tributyl phosphate (TBP) were evaluated for use in the separation and recovery of americium and plutonium from nuclear waste solutions. Due to their chemical nature, these extractants selectively complex americium and plutonium contaminants onto the particles, which can then be recovered from the solution by using a magnet. The partition coefficients were larger than those expected based on liquid[liquid extractions, and the extraction proceeded with rapid kinetics. Extractants were stripped from the particles with alcohols and 400-fold volume reductions were achieved. Particles were more sensitive to acid hydrolysis than to radiolysis. Overall, the optimization of a suitable NMCS particle for TRU separation was achieved under simulant conditions, and a MACS unit is currently being designed for an in-lab demonstration

  4. Hysteresis losses in iron oxide nanoparticles prepared by glass crystallization or wet chemical precipitation

    International Nuclear Information System (INIS)

    Mueller, Robert; Dutz, Silvio; Hergt, Rudolf; Schmidt, Christopher; Steinmetz, Hanna; Zeisberger, Matthias; Gawalek, Wolfgang

    2007-01-01

    Ferrofluids were prepared from glass crystallized as well as wet precipitated iron oxide particles. Comparing hysteresis losses versus applied field amplitude from particles in immobilized state (powder) and in fluid state (ferrofluid) shows in some cases anomalous large losses at low magnetic fields. The influence of texture on the losses was investigated

  5. Chemical Composition and Rheological Properties of Set Yoghurt Prepared from Skimmed Milk Treated with Horseradish Peroxidase

    Directory of Open Access Journals (Sweden)

    Yan Wen

    2012-01-01

    Full Text Available The aim of this work is to determine the impact of an enzymatic treatment on the fermentation and rheological properties of set yoghurt prepared from skimmed milk. Skimmed bovine milk was treated with horseradish peroxidase added at the level of 645 U per g of proteins in the presence (addition level of 7.8 mmol per L of milk or absence of ferulic acid as a cross-linking agent, and used to prepare set yoghurt with commercial direct vat set starter culture. The evaluation showed that the treatment of skimmed milk with horseradish peroxidase enhanced its apparent viscosity, and storage and loss moduli. The prepared yoghurt contained protein, fat and total solids at 3.49–3.59, 0.46–0.52 and 15.23–15.43 %, respectively, had titratable acidity of 0.83–0.88 %, and no significant difference in the composition was found among the yoghurt samples (p>0.05. Compared to the control yoghurt, the yoghurt prepared from the milk treated with horseradish peroxidase had a higher apparent viscosity, storage and loss moduli and flow behavior indices, especially when ferulic acid was added. Yoghurt samples from the skimmed milk treated either with horseradish peroxidase only or with the additional ferulic acid treatment had better structural reversibility, because their hysteresis loop area during rheological analysis was larger (p<0.05.

  6. 21 CFR 1308.23 - Exemption of certain chemical preparations; application.

    Science.gov (United States)

    2010-04-01

    ... special research purposes and not for general administration to a human being or other animal, if the... concentration that the packaged quantity does not present any significant potential for abuse (the type of packaging and the history of abuse of the same or similar preparations may be considered in determining the...

  7. The preparation of low electroendosmosis agarose and its physico-chemical property

    Science.gov (United States)

    Hu, Rugui; Liu, Xiaolei; Liu, Li; Zhang, Quanbin; Zhang, Hong; Niu, Xizhen

    2007-10-01

    Studies on Gelidium amansii agar fractionations were carried out in this paper. Gelidium amansii agar was fractionated on DEAE-Cellulose, and four fractions were obtained sequentially. The fractions were analyzed on physical and chemical properties, and IR and 13C-NMR spectroscopy applied for elucidating the chemical structure. Among the four fractions obtained, water fraction measured up to the standard of low EEO agarose. The sulfate content, ash content, electroendosmosis and gel strength (1%) of water fraction were 0.16%, 0.34%, 0.12 and 1 130g/cm2 respectively, similar to those of the Sigma products.

  8. COMPARISON OF PHYSICO-CHEMICAL AND SENSORY QUALITY OF SAUSAGES PREPARED FROM SPENT DUCK AND HEN MEAT

    Directory of Open Access Journals (Sweden)

    Rajesh Kumar

    2016-06-01

    Full Text Available A study was conducted to assess the comparative quality of sausages prepared from different combination of spent duck and spent hen meats in terms of physico-chemical and sensory attributes. Sausages from 75% spent duck and 25% spent hen (T1 , 50% spent duck and 50% spent hen (T2 and 25% spent duck and 75% spent hen (T3 meats were prepared by standard methods. The quality parameter studies included pH, thiobarbituric acid (TBA, tyrosine value (TV, moisture (%, protein (%, fat (% and sensory attributes. Results revealed that pH, TV, and protein showed insignificant differences between the treatments whereas TBA, moisture and fat varied significantly (p T2 > T1.

  9. Nuclear chemical method for preparation of free carbenium ions and radiochemical investigation of reactions of these particles

    International Nuclear Information System (INIS)

    Nefedov, V.D.; Sinotova, E.N.; Toropova, M.A.

    1980-01-01

    Tritium nuclear transformation (β-decay) in the composition of the molecules of hydrocarbons, appearance of primary molecular ions and formation of free carbenium ion are the main items of nuclear-chemical method of preparation of free carbenium ions. The method permits to prepare carbenium ions present in free state, i.e. without counterion and without solvate sheath of variou nitial localization of the charge. The rate of carbenium ion generation is strictly definite and does not depend upon outer conditions. The method suggested permits to prepare carbenium ions in all phases, study their reactions with individual substances in gaseous, liquid and solid states. The study of ion-molecular reactions is carried out using radiochemical method. The analysis of the products is made using the method of gaseous radiochromatography. Development of preparation techniques of carbenium ions and their analogues, study of the reactions of these particles with different classes of compounds, investigation of the effect of different factors upon procedure of ion-molecular reactions are the main directions of the investigations

  10. Surface preparation process of a uranium titanium alloy, in particular for chemical nickel plating

    International Nuclear Information System (INIS)

    Henri, A.; Lefevre, D.; Massicot, P.

    1987-01-01

    In this process the uranium alloy surface is attacked with a solution of lithium chloride and hydrochloric acid. Dissolved uranium can be recovered from the solution by an ion exchange resin. Treated alloy can be nickel plated by a chemical process [fr

  11. 78 FR 40175 - Exempt Chemical Preparations Under the Controlled Substances Act

    Science.gov (United States)

    2013-07-03

    ...Standard, Inc M-8270-04-ASL, Method 8270B-- Amber ampule: 1 mL...... 1/28/2013 Base/Neutrals Mix. Accu... CSA and its implementing regulations are designed to prevent, detect, and eliminate the diversion of... controlled substances and listed chemicals for legitimate medical, scientific, research, and industrial...

  12. Microwave-ultrasound combined reactor suitable for atmospheric sample preparation procedure of biological and chemical products

    NARCIS (Netherlands)

    Lagha, A.; Chemat, S.; Bartels, P.V.; Chemat, F.

    1999-01-01

    A compact apparatus in which a specific position can be irradiated by microwaves (MW) and ultrasound (US) simultaneously has been developed. The MW-US reactor has been designed for atmospheric pressure digestion and dissolution of biological and chemical products. The reactor can treat a range of

  13. Chemical modifiers in electrothermal atomic absorption determination of Platinum and Palladium containing preparations in blood serum

    Directory of Open Access Journals (Sweden)

    Аntonina Alemasova

    2012-11-01

    Full Text Available The biological liquids matrixes influence on the characteristic masses and repeatability of Pt and Pd electrothermal atomic absorption spectroscopy (ETAAS determination was studied. The chemical modifiers dimethylglyoxime and ascorbic acid for matrix interferences elimination and ETAAS results repeatability improvement were proposed while bioliquids ETAAS analysis, and their action mechanism was discussed.

  14. Composition and properties of nanocrystalline Zn S thin films prepared by a new chemical bath deposition route

    International Nuclear Information System (INIS)

    Sahraei, R.; Goudarzi, A.; Ahmadpoor, H.; Motedayen Aval, Gh.

    2006-01-01

    Zinc sulfide nanocrystalline thin films were prepared by a new chemical bath deposition route on soda lime glass and quartz substrates using a weak acidic bath, in which disodium salt of ethylenediaminetetraacetic acid (EDTA) acts as a complexing agent and thioacetamide acts as a source of sulfide ions. The thickness of the films varied from a few nm to 500 nm. The chemical composition of films was studied by energy-dispersive X-ray analyzer and Fourier transform infrared spectroscopy. The films are very close to Zinc sulfide stoichiometry and we did not observed any organic compounds in the impurity form in them. X-ray diffraction indicates that the film and powder formed in the same reaction bath have cubic zinc blende structure. The films have high transmittance of about 75% in the visible region. The optical band-gap energy (E g ) was determined to be 3.75 eV from the absorption spectrophotometry measurements.

  15. Preparation of ZnS microdisks using chemical bath deposition and ZnS/p-Si heterojunction solar cells

    Science.gov (United States)

    Hsiao, Y. J.; Meen, T. H.; Ji, L. W.; Tsai, J. K.; Wu, Y. S.; Huang, C. J.

    2013-10-01

    The synthesis and heterojunction solar cell properties of ZnS microdisks prepared by the chemical bath deposition method were investigated. The ZnS deposited on the p-Si blanket substrate exhibits good coverage. The lower reflectance spectra were found as the thickness of the ZnS film increased. The optical absorption spectra of the 80 °C ZnS microdisk exhibited a band-gap energy of 3.4 eV and the power conversion efficiency (PCE) of the AZO/ZnS/p-Si heterojunction solar cell with a 300 nm thick ZnS film was η=2.72%.

  16. Fabrication and characterization of chemical sensors made from nanostructured films of poly(o-ethoxyaniline) prepared with different doping acids

    Energy Technology Data Exchange (ETDEWEB)

    Brugnollo, E.D. [EMBRAPA Instrumentacao Agropecuaria, CP 741, CEP 13560-970, Sao Carlos, SP (Brazil); Instituto de Fisica de Sao Carlos, USP, CP 369, CEP 13560-970, Sao Carlos, SP (Brazil); Paterno, L.G. [Departamento de Engenharia de Sistemas Eletronicos, EPUSP, CEP 05508-900, Sao Paulo, SP (Brazil)], E-mail: paterno@lme.usp.br; Leite, F.L. [EMBRAPA Instrumentacao Agropecuaria, CP 741, CEP 13560-970, Sao Carlos, SP (Brazil); Instituto de Fisica de Sao Carlos, USP, CP 369, CEP 13560-970, Sao Carlos, SP (Brazil); Fonseca, F.J. [Departamento de Engenharia de Sistemas Eletronicos, EPUSP, CEP 05508-900, Sao Paulo, SP (Brazil); Constantino, C.J.L.; Antunes, P.A. [Departamento de Fisica, Quimica e Biologia, FCT-UNESP, CEP 19060-900, Presidente Prudente, SP (Brazil); Mattoso, L.H.C. [EMBRAPA Instrumentacao Agropecuaria, CP 741, CEP 13560-970, Sao Carlos, SP (Brazil)

    2008-03-31

    Chemical sensors made from nanostructured films of poly(o-ethoxyaniline) POEA and poly(sodium 4-styrene sulfonate) PSS are produced and used to detect and distinguish 4 chemicals in solution at 20 mM, including sucrose, NaCl, HCl, and caffeine. These substances are used in order to mimic the 4 basic tastes recognized by humans, namely sweet, salty, sour, and bitter, respectively. The sensors are produced by the deposition of POEA/PSS films at the top of interdigitated microelectrodes via the layer-by-layer technique, using POEA solutions containing different dopant acids. Besides the different characteristics of the POEA/PSS films investigated by UV-Vis and Raman spectroscopies, and by atomic force microscopy, it is observed that their electrical response to the different chemicals in liquid media is very fast, in the order of seconds, systematical, reproducible, and extremely dependent on the type of acid used for film fabrication. The responses of the as-prepared sensors are reproducible and repetitive after many cycles of operation. Furthermore, the use of an 'electronic tongue' composed by an array of these sensors and principal component analysis as pattern recognition tool allows one to reasonably distinguish test solutions according to their chemical composition.

  17. Chemical compositions of spherical titanium powders prepared by RF induction plasma

    International Nuclear Information System (INIS)

    Gu Zhongtao; Jin Yuping; Ye Gaoying

    2012-01-01

    Spherical titanium powders were prepared by RF induction plasma technology. The particle size is essentially un- changed, while the particle size distribution is relatively narrow after spheroidization processing. X-ray diffraction (XRD) random testing of the spherical titanium powders shows no structure and phase changes. The content of O, H, N and C decreases, while the content of Ti increases slightly. It indicates that spheroidization with RF plasma can enhance powder purity. (authors)

  18. Preparation, physical-chemical characterisation and cytocompatibility of calcium carbonate cements

    OpenAIRE

    Combes, Christèle; Miao, Baoji; Bareille, Reine; Rey, Christian

    2006-01-01

    The feasibility of calcium carbonate cements involving the recrystallisation of metastable calcium carbonate varieties has been demonstrated. Calcium carbonate cement compositions presented in this paper can be prepared straightforwardly by simply mixing water (liquid phase) with two calcium carbonate phases (solid phase) which can be easily obtained by precipitation. An original cement composition was obtained by mixing amorphous calcium carbonate and vaterite with an aqueous medium. The cem...

  19. PREPARATION AND CHARACTERIZATION OF IRON SULPHIDE THIN FILMS BY CHEMICAL BATH DEPOSITION METHOD

    Directory of Open Access Journals (Sweden)

    Anuar Kassim

    2010-06-01

    Full Text Available FeS2 thin films have been deposited by using low cost chemical bath deposition technique. The films obtained under deposition parameters such as bath temperature (90 °C, deposition period (90 min, electrolyte concentration (0.15 M and pH of the reactive mixture (pH 2.5. The thin films were characterized using X-ray diffraction and atomic force microscopy in order to study the structural and morphological properties. The band gap energy, transition type and absorption properties were determined using UV-Vis Spectrophotometer. X-ray diffraction displayed a pattern consistent with the formation of an orthorhombic structure, with a strong (110 preferred orientation. Atomic force microscopy image showed the substrate surface is well covered with irregular grains. A direct band gap of 1.85 eV was obtained according to optical absorption studies.   Keywords: Iron sulfide, X-ray diffraction, chemical bath deposition, thin films

  20. Ionic Liquids and Cellulose: Dissolution, Chemical Modification and Preparation of New Cellulosic Materials

    Science.gov (United States)

    Isik, Mehmet; Sardon, Haritz; Mecerreyes, David

    2014-01-01

    Due to its abundance and a wide range of beneficial physical and chemical properties, cellulose has become very popular in order to produce materials for various applications. This review summarizes the recent advances in the development of new cellulose materials and technologies using ionic liquids. Dissolution of cellulose in ionic liquids has been used to develop new processing technologies, cellulose functionalization methods and new cellulose materials including blends, composites, fibers and ion gels. PMID:25000264

  1. Ionic Liquids and Cellulose: Dissolution, Chemical Modification and Preparation of New Cellulosic Materials

    Directory of Open Access Journals (Sweden)

    Mehmet Isik

    2014-07-01

    Full Text Available Due to its abundance and a wide range of beneficial physical and chemical properties, cellulose has become very popular in order to produce materials for various applications. This review summarizes the recent advances in the development of new cellulose materials and technologies using ionic liquids. Dissolution of cellulose in ionic liquids has been used to develop new processing technologies, cellulose functionalization methods and new cellulose materials including blends, composites, fibers and ion gels.

  2. Preparation of potassium tantalate niobate thin films by chemical solution deposition and their characterization

    Czech Academy of Sciences Publication Activity Database

    Buršík, Josef; Železný, Vladimír; Vaněk, Přemysl

    2005-01-01

    Roč. 25, č. 12 (2005), s. 2151-2154 ISSN 0955-2219 R&D Projects: GA ČR GA202/02/0238; GA MŠk(CZ) LN00A028; GA MŠk OC 528.001 Institutional research plan: CEZ:AV0Z40320502 Keywords : films * tantalates * chemical solution deposition Subject RIV: CA - Inorganic Chemistry Impact factor: 1.567, year: 2005

  3. Enamels in stained glass windows: Preparation, chemical composition, microstructure and causes of deterioration

    International Nuclear Information System (INIS)

    Schalm, O.; Van der Linden, V.; Frederickx, P.; Luyten, S.; Van der Snickt, G.; Caen, J.; Schryvers, D.; Janssens, K.; Cornelis, E.; Van Dyck, D.; Schreiner, M.

    2009-01-01

    Stained glass windows incorporating dark blue and purple enamel paint layers are in some cases subject to severe degradation while others from the same period survived the ravages of time. A series of dark blue, green-blue and purple enamel glass paints from the same region (Northwestern Europe) and from the same period (16-early 20th centuries) has been studied by means of a combination of microscopic X-ray fluorescence analysis, electron probe micro analysis and transmission electron microscopy with the aim of better understanding the causes of the degradation. The chemical composition of the enamels diverges from the average chemical composition of window glass. Some of the compositions appear to be unstable, for example those with a high concentration of K 2 O and a low content of CaO and PbO. In other cases, the deterioration of the paint layers was caused by the less than optimal vitrification of the enamel during the firing process. Recipes and chemical compositions indicate that glassmakers of the 16-17th century had full control over the color of the enamel glass paints they made. They mainly used three types of coloring agents, based on Co (dark blue), Mn (purple) and Cu (light-blue or green-blue) as coloring elements. Blue-purple enamel paints were obtained by mixing two different coloring agents. The coloring agent for red-purple enamel, introduced during the 19th century, was colloidal gold embedded in grains of lead glass.

  4. Preparation of SmBiO{sub 3} buffer layer on YSZ substrate by an improved chemical solution deposition route

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xiaolei [Key Laboratory of Advanced Technologies of Materials (Ministry of Education of China), Superconductivity and New Energy R& D Center, Mail Stop 165#, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Pu, Minghua, E-mail: mhpu@home.swjtu.edu.cn [Key Laboratory of Advanced Technologies of Materials (Ministry of Education of China), Superconductivity and New Energy R& D Center, Mail Stop 165#, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Zhao, Yong [Key Laboratory of Advanced Technologies of Materials (Ministry of Education of China), Superconductivity and New Energy R& D Center, Mail Stop 165#, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); School of Materials Science and Engineering, University of New South Wale, Sydney, NSW 2052 (Australia)

    2016-12-15

    Highlights: • The proper conditions for SBO growth are 794 °C for 60 min in flowing Ar gas, the temperature of epitaxial growth is relatively low. • The total time by SSD technique for organic solvent removing, salts decomposition and layer growth is not up to 2 h, which are much less than that needed for traditional CSD of over 10 h. • SBO layer on YSZ prepared by SSD technique are suitable for the growth of YBCO, The results may be the usable reference for continuous preparation of SBO buffer layer on IBAD-YSZ/Ni-based alloy tapes. - Abstract: A quick route for chemical solution deposition (CSD) has been developed to prepare SmBiO{sub 3} (SBO) layers on yttria stabilized zirconia (YSZ) substrates rapidly by using of solid state decomposition (SSD) technique. The proper conditions for volatilization of lactic acid, which as solvent in precursor coated layer, and SBO growth are 115°C for 30 min and 794°C for 60 min in flowing Ar gas. The coated layers are amorphous structure of mixture oxides and quasi-crystal structure of SBO before and after growth, respectively. The total time by this quick CSD route for organic solvent volatilization, salts decomposed and layer growth is not up to 2 h, which are much less than that needed for traditional CSD of over 10 h. SBO layer is directly epitaxial growth on YSZ substrate without any lattice rotation. SBO layer prepared by this quick route as well as that by traditional route are suitable for the growth of YBCO. The superconducting transition temperature and critical current density of the coated YBCO layer on SBO/YSZ obtained by this quick route are up to 90 K and 1.66 MA/cm{sup 2}. These results may be the usable reference for continuous preparation of SBO buffer layer on IBAD-YSZ/Ni-based alloy tapes.

  5. Some physico-chemical and radiation properties of plutonium-238 metal prepared by electrochemical amalgamation

    Energy Technology Data Exchange (ETDEWEB)

    Peretrukhin, V.F. [A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31 Leninsky Prospect, Moscow 119991 (Russian Federation)], E-mail: vperet@ipc.rssi.ru; Rovny, S.I. [Production Association ' Mayak' , 31 Prospect Lenin, Ozersk, Chelyabinsk Region 456784 (Russian Federation); Maslennikov, A.G. [A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31 Leninsky Prospect, Moscow 119991 (Russian Federation); Ershov, V.V.; Chinenov, P.P.; Kapitonov, V.I.; Kuvaev, V.L. [Production Association ' Mayak' , 31 Prospect Lenin, Ozersk, Chelyabinsk Region 456784 (Russian Federation)

    2007-10-11

    Pu-238 metal was prepared by electrolytic amalgamation from Pu(III) acetate aqueous solution and by followed by the thermal decomposition of the Pu amalgam. The density, specific heat power, {gamma}-spectra, neutron flux, and corrosion kinetics in dry air at ambient temperature of the prepared {sup 238}Pu metal were measured. The neutron flux and {gamma}-spectra from {sup 238}Pu metal have been attributed to spontaneous and induced fission and to ({alpha},{alpha}'{gamma}), ({alpha},p{gamma}), and ({alpha},n{gamma}) nuclear reactions on light nuclei. The electrochemically prepared {sup 238}Pu metal was shown to generate fewer neutrons, produce less gamma radiation, and contains lower {sup 10}B, {sup 19}F, and {sup 28}Si impurities in comparison with biomedical {sup 238}PuO{sub 2}. The increase of neutron flux from the sample due to the reaction {sup 18}O({alpha},n{gamma}) {sup 21}Ne was shown to be proportional to the increase of the mass of the {sup 238}Pu metal with time due to corrosion in dry air. {sup 238}Pu metal corrosion rate maximum and average values (1.1 x 10{sup -2} and 4.7 x 10{sup -3} mg cm{sup -2} h{sup -1}, respectively) obtained in dry air were an order of magnitude higher than the rates published for {sup 239}Pu under similar experiment conditions. The difference between the {sup 239}Pu and {sup 238}Pu metal corrosion rate and mechanism is proposed to be due to the greater radiation effects and temperature on the {sup 238}Pu surface.

  6. The dosimetric properties of phosphate glass systems prepared by different chemical nanomaterials.

    Science.gov (United States)

    Abdelhalim, Mohamed Anwar K; Al-Shamrani, Bandar Mora

    2016-12-01

    The synthesis and characterization of glass systems were carried out using prepared nanocrystals injected into a glass matrix as a thermoluminescence (TL) activator using the melt-quenching method. Sample 1 was prepared as [40P 2 O 5 50BaO:2.5MgO, 2.5Na 2 O, 5TiO 2 ], sample 2 as [37.5P 2 O 5 37.5CaO:25TiO 2 ] and sample 3 as [50P 2 O 5 -50Li 2 O]. Formation of the synthesized compound was confirmed by studying the X-ray diffraction (XRD) patterns and scanning electron microscopy (SEM) images. An annealing procedure was carried out for 1 h at 400 °C. The glow curve position and shape shifted dramatically and linearly to the higher temperature values on increasing the heating rate. A heating rate of 30 °C/s was the most suitable for obtaining a high TL response. Samples 2 and 3 have the highest TL response, which approached the effective atomic number (Z eff ) of natural bone. The observed TL sensitivity of the prepared samples 2 and 3 is less than that of commercially available 'TLD-200 chips' and LiF:Mg,Ti (TLD-100) phosphor. Sample [37.5P 2 O 5 37.5CaO:25TiO 2 ] would be useful in personal and environmental dosimetry for measuring high doses of gamma radiation. Sample [50P 2 O 5 -50Li 2 O] is a good dosimeter, although it requires the addition of an appropriate transitional metal (activator) to overcome the problem of high fading. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  7. Chemical stability of insulin. 1. Hydrolytic degradation during storage of pharmaceutical preparations.

    Science.gov (United States)

    Brange, J; Langkjaer, L; Havelund, S; Vølund, A

    1992-06-01

    Hydrolysis of insulin has been studied during storage of various preparations at different temperatures. Insulin deteriorates rapidly in acid solutions due to extensive deamidation at residue AsnA21. In neutral formulations deamidation takes place at residue AsnB3 at a substantially reduced rate under formation of a mixture of isoAsp and Asp derivatives. The rate of hydrolysis at B3 is independent of the strength of the preparation, and in most cases the species of insulin, but varies with storage temperature and formulation. Total transformation at B3 is considerably reduced when insulin is in the crystalline as compared to the amorphous or soluble state, indicating that formation of the rate-limiting cyclic imide decreases when the flexibility of the tertiary structure is reduced. Neutral solutions containing phenol showed reduced deamidation probably because of a stabilizing effect of phenol on the tertiary structure (alpha-helix formation) around the deamidating residue, resulting in a reduced probability for formation of the intermediate imide. The ratio of isoAsp/Asp derivative was independent of time and temperature, suggesting a pathway involving only intermediate imide formation, without any direct side-chain hydrolysis. However, increasing formation of Asp relative to isoAsp derivative was observed with decreasing flexibility of the insulin three-dimensional structure in the formulation. In certain crystalline suspensions a cleavage of the peptide bond A8-A9 was observed. Formation of this split product is species dependent: bovine greater than porcine greater than human insulin. The hydrolytic cleavage of the peptide backbone takes place only in preparations containing rhombohedral crystals in addition to free zinc ions.

  8. Evaluation of alternative chemical additives for high-level waste vitrification feed preparation processing

    International Nuclear Information System (INIS)

    Seymour, R.G.

    1995-01-01

    During the development of the feed processing flowsheet for the Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS), research had shown that use of formic acid (HCOOH) could accomplish several processing objectives with one chemical addition. These objectives included the decomposition of tetraphenylborate, chemical reduction of mercury, production of acceptable rheological properties in the feed slurry, and controlling the oxidation state of the glass melt pool. However, the DEPF research had not shown that some vitrification slurry feeds had a tendency to evolve hydrogen (H 2 ) and ammonia (NH 3 ) as the result of catalytic decomposition of CHOOH with noble metals (rhodium, ruthenium, palladium) in the feed. Testing conducted at Pacific Northwest Laboratory and later at the Savannah River Technical Center showed that the H 2 and NH 3 could evolve at appreciable rates and quantities. The explosive nature of H 2 and NH 3 (as ammonium nitrate) warranted significant mitigation control and redesign of both facilities. At the time the explosive gas evolution was discovered, the DWPF was already under construction and an immediate hardware fix in tandem with flowsheet changes was necessary. However, the Hanford Waste Vitrification Plant (HWVP) was in the design phase and could afford to take time to investigate flowsheet manipulations that could solve the problem, rather than a hardware fix. Thus, the HWVP began to investigate alternatives to using HCOOH in the vitrification process. This document describes the selection, evaluation criteria, and strategy used to evaluate the performance of the alternative chemical additives to CHOOH. The status of the evaluation is also discussed

  9. Preparation and characterization of activated carbon from pistachio nut shells via microwave-induced chemical activation

    International Nuclear Information System (INIS)

    Foo, K.Y.; Hameed, B.H.

    2011-01-01

    In this work, pistachio nut shell, a biomass residue abundantly available from the pistachio nut processing industries, was utilized as a feedstock for the preparation of activated carbon (PSAC) via microwave assisted KOH activation. The activation step was performed at the microwave input power of 600 W and irradiation time of 7 min. The porosity, functional and surface chemistry were featured by means of low temperature nitrogen adsorption, scanning electron microscopy and Fourier transform infrared spectroscopy. Result showed that the BET surface area, Langmuir surface area, and total pore volume of PSAC were 700.53 m 2 g -1 , 1038.78 m 2 g -1 and 0.375 m 3 g -1 , respectively. The adsorptive property of PSAC was tested using methylene blue dye as the targeted adsorbate. Equilibrium data was best fitted by the Langmuir isotherm model, showing a monolayer adsorption capacity of 296.57 mg g -1 . The study revealed the potentiality of microwave-induced activation as a viable activation method. -- Highlights: → Pistachio nut shell activated carbon (PSAC) was prepared via microwave assisted KOH activation. → The activation step was performed at the microwave input power of 600 W and irradiation time of 7 min. → BET surface area of PSAC was 700.53 m 2 /g. → Monolayer adsorption capacity of PSAC for MB was 296.57 mg/g.

  10. Preparation and characterization of activated carbon from pistachio nut shells via microwave-induced chemical activation

    Energy Technology Data Exchange (ETDEWEB)

    Foo, K. Y. [School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Hameed, B.H., E-mail: chbassim@eng.usm.my [School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia)

    2011-07-15

    In this work, pistachio nut shell, a biomass residue abundantly available from the pistachio nut processing industries, was utilized as a feedstock for the preparation of activated carbon (PSAC) via microwave assisted KOH activation. The activation step was performed at the microwave input power of 600 W and irradiation time of 7 min. The porosity, functional and surface chemistry were featured by means of low temperature nitrogen adsorption, scanning electron microscopy and Fourier transform infrared spectroscopy. Result showed that the BET surface area, Langmuir surface area, and total pore volume of PSAC were 700.53 m{sup 2} g{sup -1}, 1038.78 m{sup 2} g{sup -1} and 0.375 m{sup 3} g{sup -1}, respectively. The adsorptive property of PSAC was tested using methylene blue dye as the targeted adsorbate. Equilibrium data was best fitted by the Langmuir isotherm model, showing a monolayer adsorption capacity of 296.57 mg g{sup -1}. The study revealed the potentiality of microwave-induced activation as a viable activation method. -- Highlights: {yields} Pistachio nut shell activated carbon (PSAC) was prepared via microwave assisted KOH activation. {yields} The activation step was performed at the microwave input power of 600 W and irradiation time of 7 min. {yields} BET surface area of PSAC was 700.53 m{sup 2}/g. {yields} Monolayer adsorption capacity of PSAC for MB was 296.57 mg/g.

  11. Chemical analysis of freshly prepared and stored capsaicin solutions: implications for tussigenic challenges.

    Science.gov (United States)

    Kopec, Scott E; DeBellis, Ronald J; Irwin, Richard S

    2002-01-01

    The purpose of this study was to assess the stability of stored capsaicin solutions and the actual concentrations of prepared solutions. Capsaicin solutions ranging in concentration from 0.5 to 128 microM were mixed and analyzed using high performance liquid chromatography. Samples of varying concentrations were then stored under 4 environmental conditions: 4 degrees C and protected from light, room temperature (RT) exposed to light, RT protected from light, and -20 degrees C and protected from light. The concentrations were measured every other month for 1 year. Actual concentrations of freshly prepared solutions were on average 88.3% of predicted. For solutions stored at 4 degrees C, there was a decrease only in the lower concentrations (0.5, 1, and 2 microM) after 2 months (P=0.003). Solutions stored at RT exposed to light decreased in concentration after 6 months (P=0.020), and solutions stored at RT protected from light decreased in concentration after 4 months (P=0.026). The group stored at -20 degrees C decreased in concentration after 1 year (P=0.033). We conclude that the actual concentration of capsaicin solution is less than predicted, and solutions of 4 microM or higher concentration are stable for 1 year if stored at 4 degrees C protected from light.

  12. The structure and growth mechanism of Si nanoneedles prepared by plasma-enhanced chemical vapor deposition

    Czech Academy of Sciences Publication Activity Database

    Červenka, Jiří; Ledinský, Martin; Stuchlík, Jiří; Stuchlíková, The-Ha; Bakardjieva, Snejana; Hruška, Karel; Fejfar, Antonín; Kočka, Jan

    2010-01-01

    Roč. 21, č. 41 (2010), 415604/1-415604/7 ISSN 0957-4484 R&D Projects: GA MŠk(CZ) LC06040; GA AV ČR KAN400100701; GA MŠk LC510 EU Projects: European Commission(XE) 240826 - PolySiMode Institutional research plan: CEZ:AV0Z10100521; CEZ:AV0Z40320502 Keywords : nanoneedles * nanowires * silicon * plasma * chemical vapor deposition * crystal structure * growth * phonon * SEM * Raman Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.644, year: 2010

  13. A non-chemically selective top-down approach towards the preparation of hierarchical TS-1 zeolites with improved oxidative desulfurization catalytic performance.

    Science.gov (United States)

    Du, Shuting; Chen, Xiaoxin; Sun, Qiming; Wang, Ning; Jia, Mingjun; Valtchev, Valentin; Yu, Jihong

    2016-02-28

    Hierarchical TS-1 zeolites with secondary macropores have been successfully prepared by using two different fluoride-containing chemical etching post-treated routes. Hierarchical TS-1 zeolites exhibited a chemical composition similar to that of the parent material and showed remarkably enhanced catalytic activity in oxidative desulfurization reaction.

  14. Preparation of porous bio-char and activated carbon from rice husk by leaching ash and chemical activation.

    Science.gov (United States)

    Ahiduzzaman, Md; Sadrul Islam, A K M

    2016-01-01

    Preparation porous bio-char and activated carbon from rice husk char study has been conducted in this study. Rice husk char contains high amount silica that retards the porousness of bio-char. Porousness of rice husk char could be enhanced by removing the silica from char and applying heat at high temperature. Furthermore, the char is activated by using chemical activation under high temperature. In this study no inert media is used. The study is conducted at low oxygen environment by applying biomass for consuming oxygen inside reactor and double crucible method (one crucible inside another) is applied to prevent intrusion of oxygen into the char. The study results shows that porous carbon is prepared successfully without using any inert media. The adsorption capacity of material increased due to removal of silica and due to the activation with zinc chloride compared to using raw rice husk char. The surface area of porous carbon and activated carbon are found to be 28, 331 and 645 m(2) g(-1) for raw rice husk char, silica removed rice husk char and zinc chloride activated rice husk char, respectively. It is concluded from this study that porous bio-char and activated carbon could be prepared in normal environmental conditions instead of inert media. This study shows a method and possibility of activated carbon from agro-waste, and it could be scaled up for commercial production.

  15. Textural and chemical characterization of activated carbon prepared from shell of african palm (Elaeis guineensis by chemical activation with CaCl2 and MgCl2

    Directory of Open Access Journals (Sweden)

    Sergio Acevedo

    2015-09-01

    Full Text Available Activated carbons through chemical activation of African palm shells (Elaeis guineensis with magnesium chloride and calcium chloride solutions at different concentrations were obtained. The prepared materials were characterized textural and chemically. The results show that activated carbons with higher values of surface area and pore volume are obtained when solutions with lower concentrations of the activating agent are used. The obtained activated carbons have surface areas and pore volumes with values between 10 and 501 m2 /g and 0.01 and 0.29 cm3 /g respectively. Immersion enthalpies values of solids in water were between -14.3 and -32.8 J/g and benzene between -13.9 and -38.6 J/g. Total acidity and basicity of the activated carbons had values between 23 and 262 μmol/g 123 and 1724 μmol/g respectively. pH at the point of zero charge was also determined with values between 4.08 and 9.92 for set of activated carbons . The results show that activation with CaCl2 and MgCl2 salts produce activated carbons with pores in the range of mesopores for facilitate entry of the adsorbate into the materials.

  16. Chemical mechanical polishing characteristics of ITO thin film prepared by RF magnetron sputtering

    International Nuclear Information System (INIS)

    Lee, Kang-Yeon; Choi, Gwon-Woo; Kim, Yong-Jae; Choi, Youn-Ok; Kim, Nam-Oh

    2012-01-01

    Indium-tin-oxide (ITO) thin films have attracted intensive interest because of their unique properties of good conductivity, high optical transmittance over the visible region and easy patterning ability. ITO thin films have found many applications in anti-static coatings, thermal heaters, solar cells, flat panel displays (FPDs), liquid crystal displays (LCDs), electroluminescent devices, sensors and organic light-emitting diodes (OLEDs). ITO thin films are generally fabricated by using various methods, such as spraying, chemical vapor deposition (CVD), evaporation, electron gun deposition, direct current electroplating, high frequency sputtering, and reactive sputtering. In this research, ITO films were grown on glass substrates by using a radio-frequency (RF) magnetron sputtering method. In order to achieve a high transmittance and a low resistivity, we examined the various film deposition conditions, such as substrate temperature, working pressure, annealing temperature, and deposition time. Next, in order to improve the surface quality of the ITO thin films, we performed a chemical mechanical polishing (CMP) with different process parameters and compared the electrical and the optical properties of the polished ITO thin films. The best CMP conditions with a high removal rate, low nonuniformity, low resistivity and high transmittance were as follows: platen speed, head speed, polishing time, and slurry flow rate of 30 rpm, 30 rpm, 60 sec, and 60 ml/min, respectively.

  17. Transparent conducting oxide films of group V doped titania prepared by aqueous chemical solution deposition

    International Nuclear Information System (INIS)

    Elen, Ken; Capon, Boris; De Dobbelaere, Christopher; Dewulf, Daan; Peys, Nick; Detavernier, Christophe; Hardy, An; Van Bael, Marlies K.

    2014-01-01

    Transparent conducting oxide (TCO) films of titania doped with vanadium (V), niobium (Nb) and tantalum (Ta) are obtained by aqueous Chemical Solution Deposition (CSD). The effect of the dopant on the crystallization and microstructure of the resulting films is examined by means of X-ray diffraction and electron microscopy. During annealing of the thin films, in-situ characterization of the crystal structure and sheet resistance is carried out. Niobium doped anatase films, obtained after annealing in forming gas, show a resistivity of 0,28 Ohm cm, which is the lowest resistivity reported for a solution deposited anatase-based TCO so far. Here, we demonstrate that aqueous CSD may provide a strategy for scalable TCO production in the future. - Highlights: • Aqueous chemical solution deposition of doped titanium dioxide • Doping delays the phase transition from anatase to rutile • Lowest resistivity after doping with niobium and annealing in Forming Gas • Transparency higher than 80% in the visible range of optical spectrum

  18. Transparent conducting oxide films of group V doped titania prepared by aqueous chemical solution deposition

    Energy Technology Data Exchange (ETDEWEB)

    Elen, Ken [Inorganic and Physical Chemistry, Institute for Materials Research, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek (Belgium); IMEC vzw division IMOMEC, Agoralaan Building D, B-3590 Diepenbeek (Belgium); Strategisch Initiatief Materialen (SIM), SoPPoM Program (Belgium); Capon, Boris [Strategisch Initiatief Materialen (SIM), SoPPoM Programm (Belgium); Coating and Contacting of Nanostructures, Ghent University, Krijgslaan 281 S1, B-9000 Ghent (Belgium); De Dobbelaere, Christopher [Inorganic and Physical Chemistry, Institute for Materials Research, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek (Belgium); Dewulf, Daan [Inorganic and Physical Chemistry, Institute for Materials Research, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek (Belgium); IMEC vzw division IMOMEC, Agoralaan Building D, B-3590 Diepenbeek (Belgium); Peys, Nick [Inorganic and Physical Chemistry, Institute for Materials Research, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek (Belgium); IMEC vzw, Kapeldreef 75, B-3001 Heverlee (Belgium); Detavernier, Christophe [Coating and Contacting of Nanostructures, Ghent University, Krijgslaan 281 S1, B-9000 Ghent (Belgium); Hardy, An [Inorganic and Physical Chemistry, Institute for Materials Research, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek (Belgium); IMEC vzw division IMOMEC, Agoralaan Building D, B-3590 Diepenbeek (Belgium); Van Bael, Marlies K., E-mail: marlies.vanbael@uhasselt.be [Inorganic and Physical Chemistry, Institute for Materials Research, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek (Belgium); IMEC vzw division IMOMEC, Agoralaan Building D, B-3590 Diepenbeek (Belgium)

    2014-03-31

    Transparent conducting oxide (TCO) films of titania doped with vanadium (V), niobium (Nb) and tantalum (Ta) are obtained by aqueous Chemical Solution Deposition (CSD). The effect of the dopant on the crystallization and microstructure of the resulting films is examined by means of X-ray diffraction and electron microscopy. During annealing of the thin films, in-situ characterization of the crystal structure and sheet resistance is carried out. Niobium doped anatase films, obtained after annealing in forming gas, show a resistivity of 0,28 Ohm cm, which is the lowest resistivity reported for a solution deposited anatase-based TCO so far. Here, we demonstrate that aqueous CSD may provide a strategy for scalable TCO production in the future. - Highlights: • Aqueous chemical solution deposition of doped titanium dioxide • Doping delays the phase transition from anatase to rutile • Lowest resistivity after doping with niobium and annealing in Forming Gas • Transparency higher than 80% in the visible range of optical spectrum.

  19. Preparation of palladium nanoparticles on alumina surface by chemical co-precipitation method and catalytic applications

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Avvaru Praveen; Kumar, B. Prem; Kumar, A.B.V. Kiran; Huy, Bui The [Department of Chemistry, Changwon National University, Changwon 641-773 (Korea, Republic of); Lee, Yong-Ill, E-mail: yilee@changwon.ac.kr [Department of Chemistry, Changwon National University, Changwon 641-773 (Korea, Republic of)

    2013-01-15

    Highlights: Black-Right-Pointing-Pointer Facile synthesis of palladium nanoparticles on alumina surface. Black-Right-Pointing-Pointer The surface morphology and properties of the nanocrystalline powders were characterized. Black-Right-Pointing-Pointer The catalytic activities of palladium nanoparticles were investigated. - Abstract: The present work reports a chemical co-precipitation process to synthesize palladium (Pd) nanoparticles using alumina as a supporting material. The optimized temperature for the formation of nanocrystalline palladium was found to be 600 Degree-Sign C. The X-ray diffraction (XRD) and Raman spectroscopy were used to study the chemical nature of the Pd in alumina matrix. The surface morphology and properties of the nanocrystalline powders were examined using thermogravimetric analysis (TG-DTA), XRD, Raman spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The calcinations in different atmospheres including in the inert medium forms the pure nano Pd{sup 0} while in the atmospheric air indicates the existence pure Pd{sup 0} along with PdO nanoparticles. The catalytic activities of the as-synthesized nanocrystalline Pd nanoparticles in the alumina matrix were investigated in Suzuki coupling, Hiyama cross-coupling, alkene and alkyne hydrogenation, and aerobic oxidation reactions.

  20. Textural and chemical characterizations of adsorbent prepared from palm shell by potassium hydroxide impregnation at different stages.

    Science.gov (United States)

    Guo, Jia; Lua, Aik Chong

    2002-10-15

    Preparation and characterization of activated carbon from palm shell, a carbonaceous agricultural solid waste, by potassium hydroxide treatment at different stages were studied. The effects of activation temperature and chemical to sample ratio on the characteristics of the activated carbon were investigated. Fixed-bed adsorption of sulfur dioxide (SO(2)) gas was carried out to evaluate the adsorptive capacity of the samples. Desorption tests were conducted to verify the occurrence of chemisorption due to some surface functional groups or of chemical reaction between SO(2) and KOH. It was found that pre-impregnation of raw palm shell was involved in replacement of some hydrogen ions with potassium ions to form cross-linked complexes, which retarded the tar formation during carbonization, resulting in a relatively high yield. Moreover, these potassium ions accelerated the reaction as catalysts during gasification of chars by carbon dioxide. For chars with mid-impregnation, potassium hydroxide acted in two ways: (i) formation of metallic potassium by dehydration and (ii) conversion into potassium carbonate. Metallic potassium intercalated to the carbon matrix accounted for pore development and potassium carbonate layer prevented the sample from over burn-off. Post-impregnation of final products modified the textural characteristics of the sample as some pore entrances were blocked by chemicals. However, potassium hydroxide enhanced the amount of SO(2) uptaken via formation of potassium sulfite.

  1. Preparation and chemical studies on Tc(III) complexes containing polyaminocarboxylic acids

    International Nuclear Information System (INIS)

    Gonzalez, R.; Kremer, C.; Chiozzone, R.; Torres, J.; Rivero, M.; Kremer, E.; Leon, A.

    1998-01-01

    Tc(III)-edta (edta = ethylenediaminetetraacetate), Tc(III)-dtpa (dtpa = diethylenetriaminepentaacetate) and Tc(III)-mebrofenin (mebrofenin = 3-bromo-2,4,6-trimethylacetanilideiminodiacetate) complexes were prepared by ligand substitution reactions on hexakis(thiourea)technetium(III) cation with the polycarboxylates. By a combination of different techniques (UV-Vis, IR and 1 H-NMR spectroscopy, Tc elemental analyses and cerimetric titrations) it was concluded that 1:1 complexes are formed with edta and dtpa while mebrofening adopts a 2:1 (ligand to metal) stoichiometry. Complementary, molecular mechanics calculations were performed to analyze the spatial arrangement of the molecules. The stability of the Tc(III) complexes was studied in aqueous solution by paper chromatography, paper electrophoresis and cyclic voltammetry. The chelates are rather stable, in particular when compared with the precursor. (orig.)

  2. Preparation, quality control and physico-chemical properties of 99mTc-BAT-AV-45

    International Nuclear Information System (INIS)

    Jiankang Zhang; Xingqin Zhou; Xiaofeng Qin

    2012-01-01

    One novel styrylpyridine derivatives(AV-45) coupled with 99m Tc complex was synthesized. 99m Tc-BAT-AV-45 was prepared by a ligand exchange reaction employing sodium glucoheptonate, and effects of the amount of ligand, stannous chloride, sodium glucoheptonate and pH value of reaction mixture on the radiolabeling yield were studied in details. Quality control was performed by thin layer chromatography and high performance liquid chromatography. Besides the stability, partition coefficient and electrophoresis of 99m Tc-BAT-AV-45 were also investigated. The results showed that the average radiolabeling yield was (95 ± 1%) and 99m Tc-BAT-AV-45 with suitable lipophilicity was stable and uncharged at physiological pH. (author)

  3. Physico-chemical characteristics of nano-organo bentonite prepared using different organo-modifiers

    Directory of Open Access Journals (Sweden)

    A.M. Motawie

    2014-09-01

    Full Text Available Different types of nano-organo bentonite (NOB were prepared from the Egyptian Bentonite (EB. EB was characterized by energy dispersive X-ray EDX. It was purified from different impurities using a conventional method via the treatment with HCl and distilled water. The modification of the clay was carried out using different types of organo-modifiers namely; hexadecyl trimethyl ammonium bromide (HTAB, 3-aminopropyltriethoxysilane (Silane, octadecylamine (ODA, and dodecylamine (DDA. The cation exchange capacity (CEC was measured for pristine bentonite after and before modification. The NB was characterized by FTIR, XRD, TEM, and TGA techniques. The obtained results indicated that variation of the interlayer space gallery was effected by the type of the penetrator used.

  4. Role of Annealing Temperature on Morphology of Alumina Thin Film Prepared by Wet-Chemical Method

    Directory of Open Access Journals (Sweden)

    Manju Pandey

    2015-03-01

    Full Text Available In this paper, we reported the compositional, morphological and structural properties of the alumina(Al2O3 thin films prepared by sol-gel technique and annealed between 800 0C to 1200 0C for 1-hour in an air atmosphere. The deposited films were polycrystalline in nature. Thin films were found uniform and adherent to the alumina substrate. Effect of annealing temperature on structural parameters such as pore size and surface area were calculated. The result indicates that pore size and surface area was decreased by increasing annealing temperature. The material characterization was done by field emission scanning electron microscope (SEM, atomic force microscopy (AFM and Brunaur, Emmet and Teller (BET.

  5. Preparation and Performance of an Adsorption Type Gel Plugging Agent as Enhanced Oil Recovery Chemical

    Directory of Open Access Journals (Sweden)

    Xiaoping Qin

    2015-01-01

    Full Text Available A novel adsorption type gel plugging agent (ATGPA was prepared using acrylamide (AM, acrylic acid (AA, diallyl dimethyl ammonium chloride (DMDAAC, 2-acrylamido-2-methylpropanesulfonate (AMPS, formaldehyde (HCHO, resorcinol (C6H6O2, and thiocarbamide (CH4N2S as raw materials under mild conditions. ATGPA was characterized by infrared (IR spectroscopy, elemental analysis, and scanning electron microscope (SEM. It was found that ATGPA exhibited higher elastic modulus (G′ and viscous modulus (G′′ than AM/AA gel plugging agent (AAGPA under the same scanning frequency. It was also found that ATGPA had moderate temperature resistance and salt tolerance. Core plugging tests results indicated that ATGPA could achieve up to higher plugging rate (PR than AAGPA (97.2% versus 95.7% at 65°C. In addition, ATGPA possessed stronger antiscouring ability by core plugging experiments at 65°C.

  6. Preparation, physical-chemical characterisation and cytocompatibility of calcium carbonate cements.

    Science.gov (United States)

    Combes, C; Miao, Baoji; Bareille, Reine; Rey, Christian

    2006-03-01

    The feasibility of calcium carbonate cements involving the recrystallisation of metastable calcium carbonate varieties has been demonstrated. Calcium carbonate cement compositions presented in this paper can be prepared straightforwardly by simply mixing water (liquid phase) with two calcium carbonate phases (solid phase) which can be easily obtained by precipitation. An original cement composition was obtained by mixing amorphous calcium carbonate and vaterite with an aqueous medium. The cement set and hardened within 2h at 37 degrees C in an atmosphere saturated with water and the final composition of the cement consisted mostly of aragonite. The hardened cement was microporous and showed poor mechanical properties. Cytotoxicity tests revealed excellent cytocompatibility of calcium carbonate cement compositions. Calcium carbonates with a higher solubility than the apatite formed for most of the marketed calcium phosphate cements might be of interest to increase biomedical cement resorption rates and to favour its replacement by bone tissue.

  7. Tamoxifen-loaded polymeric micelles: preparation, physico-chemical characterization and in vitro evaluation studies.

    Science.gov (United States)

    Cavallaro, Gennara; Maniscalco, Laura; Licciardi, Mariano; Giammona, Gaetano

    2004-11-20

    Several samples of polymeric micelles, formed by amphiphilic derivatives of PHEA, obtained by grafting into polymeric backbone of PEGs and/or hexadecylamine groups (PHEA-PEG-C(16) and PHEA-C(16)) and containing different amount of Tamoxifen, were prepared. All Tamoxifen-loaded polymeric micelles showed to increase drug water solubility. TEM studies provided evidence of the formation of supramolecular core/shell architectures containing drug, in the nanoscopic range and with spherical shape. Samples with different amount of encapsulated Tamoxifen were subjected to in vitro cytotoxic studies in order to evaluate the effect of Tamoxifen micellization on cell growth inhibition. All samples of Tamoxifen-loaded polymeric micelles showed a significantly higher antiproliferative activity in comparison with free drug, probably attributable to fluidification of cellular membranes, caused by amphiphilic copolymers, that allows a higher penetration of the drug into tumoral cells. To gain preliminary information about the potential use of prepared micelles as Tamoxifen drug delivery systems, studies evaluating drug release ability of micelle systems in media mimicking biological fluids (buffer solutions at pH 7.4 and 5.5) and in human plasma were carried out. These studies, performed evaluating the amount of Tamoxifen that remains in solution as a function of time, showed that at pH 7.4, as well as in plasma, PHEA-C(16) polymeric micelles were able to release lower drug amounts than PHEA-PEG(5000)-C(16) ones, while at pH 5.5, the behavior difference between two kind of micelles was less pronounced.

  8. Preparation of InAs(0 0 1) surface for spin injection via a chemical route

    International Nuclear Information System (INIS)

    Singh, L J; Oliver, R A; Barber, Z H; Eustace, D A; McComb, D W; Clowes, S K; Gilbertson, A M; Magnus, F; Branford, W R; Cohen, L F; Buckle, L; Buckle, P D; Ashley, T

    2007-01-01

    A wet chemical surface treatment for InAs epilayers is investigated to remove the native semiconductor oxide prior to growth of a MgO tunnel barrier and Co ferromagnetic electrode by dc magnetron sputtering. Use of a HCl etch followed by (NH 4 ) 2 S as the pre-growth surface treatment resulted in pinhole-like features in the tunnel barrier, as observed by conducting atomic force microscopy, but this detrimental effect is avoided if the etch procedure is repeated twice. High resolution transmission electron microscopy revealed that the etched samples had uniform tunnel barriers and reducing the growth temperature of the barrier from 200 to 100 0 C significantly improved the abruptness of the semiconductor/barrier interface. Electrical characterization of barrier properties illustrated that all the etched samples showed parabolic differential conductance curves indicative of tunnelling behaviour at 300 K

  9. Characterization of photoluminescent europium doped yttrium oxide thin-films prepared by metallorganic chemical vapor deposition

    International Nuclear Information System (INIS)

    McKittrick, J.; Bacalski, C.F.; Hirata, G.A.; Hubbard, K.M.; Pattillo, S.G.; Salazar, K.V.; Trkula, M.

    1998-01-01

    Europium doped yttrium oxide, (Y 1-x Eu x ) 2 O 3 , thin-films were deposited on silicon and sapphire substrates by metallorganic chemical vapor deposition (MOCVD). The films were grown in a MOCVD chamber reacting yttrium and europium tris(2,2,6,6-tetramethyl-3,5,-heptanedionates) precursors in an oxygen atmosphere at low pressures (5 Torr) and low substrate temperatures (500--700 C). The films deposited at 500 C were flat and composed of nanocrystalline regions of cubic Y 2 O 3 , grown in a textured [100] or [110] orientation to the substrate surface. Films deposited at 600 C developed from the flat, nanocrystalline morphology into a plate-like growth morphology oriented in the [111] with increasing deposition time. Monoclinic Y 2 O 3 :Eu 3+ was observed in x-ray diffraction for deposition temperatures ≥600 C on both (111) Si and (001) sapphire substrates. This was also confirmed by the photoluminescent emission spectra

  10. Chemical bath deposition of indium sulphide thin films: preparation and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Lokhande, C.D.; Ennaoui, A.; Patil, P.S.; Giersig, M.; Diesner, K.; Muller, M.; Tributsch, H. [Hahn-Meitner-Institut Berlin GmbH (Germany). Bereich Physikalische Chemie

    1999-02-26

    Indium sulphide (In{sub 2}S{sub 3}) thin films have been successfully deposited on different substrates under varying deposition conditions using chemical bath deposition technique. The deposition mechanism of In{sub 2}S{sub 3} thin films from thioacetamide deposition bath has been proposed. Films have been characterized with respect to their crystalline structure, composition, optical and electrical properties by means of X-ray diffraction, TEM, EDAX, optical absorption, TRMC (time resolved microwave conductivity) and RBS. Films on glass substrates were amorphous and on FTO (flourine doped tin oxide coated) glass substrates were polycrystalline (element of phase). The optical band gap of In{sub 2}S{sub 3} thin film was estimated to be 2.75 eV. The as-deposited films were photoactive as evidenced by TRMC studies. The presence of oxygen in the film was detected by RBS analysis. (orig.) 27 refs.

  11. Investigation of CdS/InP heterojunction prepared by chemical bath deposition

    International Nuclear Information System (INIS)

    Rakovics, V.; Horvath, Zs.J.; Horvath, Zs.E.; Barsony, I.; Frigeri, C.; Besagni, T.

    2007-01-01

    CdS thin films have been deposited on InP and glass substrates using the chemical bath deposition technique. Baths containing CdSO 4 , thiourea, and NH 3 were used. The temperature of the deposition process was 65 C and the duration of deposition varied between 20 and 160 minutes. The properties of the CdS/InP heterojunction were investigated by TEM, EDS and X-ray diffraction. TEM pictures, EDS and X-ray rocking curves indicate the formation of a β-In 2 S 3 transition layer at the InP-CdS interface, which may reduce the lattice mismatch between InP and CdS. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  12. Biological functionalization and patterning of porous silicon prepared by Pt-assisted chemical etching

    Science.gov (United States)

    Li, Hong-Fang; Han, Huan-Mei; Wu, Ya-Guang; Xiao, Shou-Jun

    2010-04-01

    Porous silicon fabricated via Pt-assisted chemical etching of p-type Si (1 0 0) in 1:1:1 EtOH/HF/H 2O 2 solution possesses a longer durability in air and in aqueous media than anodized one, which is advantageous for biomedical applications. Its surface SiH x ( x = 1 and 2) species can react with 10-undecylenic acid completely under microwave irradiation, and subsequent derivatizations of the end carboxylic acid result in affinity capture of proteins. We applied two approaches to produce protein microarrays: photolithography and spotting. The former provides a homogeneous microarray with a very low fluorescence background, while the latter presents an inhomogeneous microarray with a high noise background.

  13. Morphology and structure of Ti-doped diamond films prepared by microwave plasma chemical vapor deposition

    Science.gov (United States)

    Liu, Xuejie; Lu, Pengfei; Wang, Hongchao; Ren, Yuan; Tan, Xin; Sun, Shiyang; Jia, Huiling

    2018-06-01

    Ti-doped diamond films were deposited through a microwave plasma chemical vapor deposition (MPCVD) system for the first time. The effects of the addition of Ti on the morphology, microstructure and quality of diamond films were systematically investigated. Secondary ion mass spectrometry results show that Ti can be added to diamond films through the MPCVD system using tetra n-butyl titanate as precursor. The spectra from X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy and the images from scanning electron microscopy of the deposited films indicate that the diamond phase clearly exists and dominates in Ti-doped diamond films. The amount of Ti added obviously influences film morphology and the preferred orientation of the crystals. Ti doping is beneficial to the second nucleation and the growth of the (1 1 0) faceted grains.

  14. Fabrication and Photovoltaic Characteristics of Coaxial Silicon Nanowire Solar Cells Prepared by Wet Chemical Etching

    Directory of Open Access Journals (Sweden)

    Chien-Wei Liu

    2012-01-01

    Full Text Available Nanostructured solar cells with coaxial p-n junction structures have strong potential to enhance the performances of the silicon-based solar cells. This study demonstrates a radial junction silicon nanowire (RJSNW solar cell that was fabricated simply and at low cost using wet chemical etching. Experimental results reveal that the reflectance of the silicon nanowires (SNWs declines as their length increases. The excellent light trapping was mainly associated with high aspect ratio of the SNW arrays. A conversion efficiency of ∼7.1% and an external quantum efficiency of ∼64.6% at 700 nm were demonstrated. Control of etching time and diffusion conditions holds great promise for the development of future RJSNW solar cells. Improving the electrode/RJSNW contact will promote the collection of carries in coaxial core-shell SNW array solar cells.

  15. Biological functionalization and patterning of porous silicon prepared by Pt-assisted chemical etching

    International Nuclear Information System (INIS)

    Li Hongfang; Han Huanmei; Wu Yaguang; Xiao Shoujun

    2010-01-01

    Porous silicon fabricated via Pt-assisted chemical etching of p-type Si (1 0 0) in 1:1:1 EtOH/HF/H 2 O 2 solution possesses a longer durability in air and in aqueous media than anodized one, which is advantageous for biomedical applications. Its surface SiHx (x = 1 and 2) species can react with 10-undecylenic acid completely under microwave irradiation, and subsequent derivatizations of the end carboxylic acid result in affinity capture of proteins. We applied two approaches to produce protein microarrays: photolithography and spotting. The former provides a homogeneous microarray with a very low fluorescence background, while the latter presents an inhomogeneous microarray with a high noise background.

  16. Study of Chemical Treatment Combined with Radiation to Prepare Biotic Elicitor for Utilization in Agriculture

    International Nuclear Information System (INIS)

    Nguyen Quoc Hien

    2010-01-01

    Chitosan was prepared from shrimp shell (alpha chitosan) and from squid pen (beta chitosan) with degree of deacetylation of about 70%. Degradation of chitosan in flake form by combined treatment with H 2 O 2 and gamma Co-60 radiation was carried out. Results showed that combined treatment was highly effective for degradation of chitosan to obtain low molecular weight of 1-2 × 10 5 . Oligochitosan was prepared by irradiation of chitosan solution of 50g/l (5%, w/v). The dose required for oligochitosan with water soluble content of more than 70% was of 32kGy and 48kGy for beta and alpha chitosan, respectively. Synergic effect of degradation of chitosan in solution with H 2 O 2 and gamma Co-60 radiation was also investigated. The dose to obtain oligochitosan was reduced from 32kGy to 4kGy for beta chitosan and from 48kGy to 8kGy for alpha chitosan. The elicitation and growth promotion effect of oligochiotsan for sugarcane and rice were investigated. Results showed that oligochitosan with water soluble content of 70-80% (Mw~5,000-10,000) exhibited the most effective elicitation and growth promotion for plant. The optimum oligochitosan concentration by spraying was of 30 and 15ppm for sugarcane and rice, respectively. The disease index of Ustilgo scitaminea and Collectotrichum falcatum on sugarcane were reduced to 44.5 and 72.3% compared to control (100%). The productivity of sugarcane was increased about 13% (8tons/ha). The disease index of Pyricularia grisea on rice was reduced to 53.0% for leaf and 34.1% for neck of bloom compared to control (100%). The productivity of rice was increased for 11-26% (0.6-1.4 tons/ha). The obtained results indicated that oligochitosan is promising to use as a biotic elicitor for plant particularly for sugarcane and rice. The procedure for production of oligochitosan elicitor by γ- irradiation method was described. (author)

  17. The Adsorption Efficiency of Chemically Prepared Activated Carbon from Cola Nut Shells by on Methylene Blue

    Directory of Open Access Journals (Sweden)

    Julius Ndi Nsami

    2013-01-01

    Full Text Available The adsorption of methylene blue from aqueous solution onto activated carbon prepared from cola nut shell has been investigated under batch mode. The influence of major parameters governing the efficiency of the process such as, solution pH, sorbent dose, initial concentration, and contact time on the removal process was investigated. The time-dependent experimental studies showed that the adsorption quantity of methylene blue increases with initial concentration and decreasing adsorbent dosage. The equilibrium time of 180 min was observed and maximum adsorption was favoured at pH 3.5. The dye removal using 0.1 g of adsorbent was more than 90%. This dosage (0.1 g was considered as the optimum dosage to remove methylene blue from aqueous solutions. The equilibrium adsorption data were analyzed by the Freundlich, Langmuir adsorption isotherm models. The kinetics of methylene blue solution was discussed by pseudo-first-order, pseudo-second-order, and Elovich models. The adsorption process follows the Elovich rate kinetic model, having a correlation coefficient in the range between 0.9811 and 1.

  18. Preparation and photocatalytic activity of chemically-bonded phosphate ceramics containing TiO2

    Science.gov (United States)

    Martins, Monize Aparecida; de Lima, Bruna de Oliveira; Ferreira, Leticia Patrício; Colonetti, Emerson; Feltrin, Jucilene; De Noni, Agenor

    2017-05-01

    Titanium dioxide was incorporated into chemically-bonded phosphate ceramic for use as photocatalytic inorganic coating. The coatings obtained were applied to unglazed ceramic tiles and cured at 350 °C. The surfaces were characterized by photocatalytic activity, determined in aqueous medium, based on the degradation of methylene blue dye. The effects of the percentage of TiO2 and the thickness of the layer on the photocatalytic efficiency were evaluated. The influence of the incorporation of TiO2 on the consolidation of the phosphate matrix coating was investigated using the wear resistance test. The crystalline phases of the coatings obtained were determined by XRD. The microstructure of the surfaces was analyzed by SEM. The thermal curing treatment did not cause a phase transition from anatase to rutile. An increase in the photocatalytic activity of the coating was observed with an increase in the TiO2 content. The dye degradation indices ranged from 14.9 to 44.0%. The photocatalytic efficiency was not correlated with the thickness of the coating layer deposited. The resistance to wear decreased with an increase in the TiO2 content. Comparison with a commercial photocatalytic ceramic coating indicated that there is a range of values for the TiO2 contents which offer potential for photocatalytic applications.

  19. The preparation and cathodoluminescence of ZnS nanowires grown by chemical vapor deposition

    Science.gov (United States)

    Huang, Meng-Wen; Cheng, Yin-Wei; Pan, Ko-Ying; Chang, Chen-Chuan; Shieu, F. S.; Shih, Han C.

    2012-11-01

    Single crystal ZnS nanowires were successfully synthesized in large quantities on Si (1 0 0) substrates by simple thermal chemical vapor deposition without using any catalyst. The morphology, composition, and crystal structure were characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), and cathodoluminescence (CL) spectroscopy. SEM observations show that the nanowires have diameters about 20-50 nm and lengths up to several tens of micrometers. XRD and TEM results confirmed that the nanowires exhibited both wurtzite and zinc blende structures with growth directions aligned along [0 0 0 2] and [1 1 1], respectively. The CL spectrum revealed emission bands in the UV and blue regions. The blue emissions at 449 and ˜581 nm were attributed to surface states and impurity-related defects of the nanowires, respectively. The perfect crystal structure of the nanowires indicates their potential applications in nanotechnology and in the fabrication of nanodevices.

  20. Comparison of selected physico-chemical properties of calcium alginate films prepared by two different methods.

    Science.gov (United States)

    Crossingham, Yazmin J; Kerr, Philip G; Kennedy, Ross A

    2014-10-01

    Sodium alginate (SA) is a naturally occurring, non-toxic, polysaccharide that is able to form gels after exposure to calcium. These gels have been used in food and biomedical industries. This is the first direct comparison of two different methods of calcium alginate film production, namely interfacial gelation (IFG) and dry cast gelation (DCG). IFG films were significantly thicker than DCG films, and were more extensively rehydrated in water and 0.1M HCl than the DCG films. During rehydration in 0.1M HCl almost all calcium ions were lost. Under scanning electron microscopy, IFG films appeared less dense than DCG films. IFG films were mechanically weaker than DCG films, and both types of film were weaker after rehydration in 0.1M HCl compared with deionized water. Permeation of theophylline (TPL) was evaluated in-vitro; the diffusion coefficient (D) of the TPL was almost 90 times lower in DCG films than IFG films when both were rehydrated in water. Although the 0.1M HCl rendered both gels more permeable to TPL, D of TPL was still about five times lower in DCG compared to IFG films. The evaluation of selected physico-chemical properties of films is important, since this information may inform the choice of gelation technique used to produce calcium alginate coatings on pharmaceutical products. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Preparation of high surface area and high conductivity polyaniline nanoparticles using chemical oxidation polymerization technique

    Science.gov (United States)

    Budi, S.; Yusmaniar; Juliana, A.; Cahyana, U.; Purwanto, A.; Imaduddin, A.; Handoko, E.

    2018-03-01

    In this work, polyaniline nanoparticles were synthesized using a chemical oxidation polymerization technique. The ammonium peroxydisulfate (APS)/aniline ratio, APS dropping time, and polymerization temperature were optimized to increase the surface area and conductivity of the polyaniline.The Fourier-transform infrared (FTIR) spectrum confirmed the formation of emeraldine salt polyaniline. X-ray diffraction (XRD) patterns indicated that amorphous and crystalline phases of the polyaniline were formed with crystallinity less than 40%. Scanning electron microscope (SEM) micrographs showed that the finest nanoparticles with uniform size distribution were obtained at the polymerization temperature of 0°C. A surface area analyzer (SAA) showed that the highest Brunauer-Emmett-Teller surface area (SBET ) of 42.14 m2/gwas obtained from an APS/aniline ratio of 0.75 with a dropping time of 0 s at a polymerization temperature of 0°C. A four-point probe measurement conducted at 75–300K indicated relatively high conductivity of the semiconductor characteristic of the polyaniline.

  2. Investigation on Fe-doped ZnO nanostructures prepared by a chemical route

    International Nuclear Information System (INIS)

    Mishra, A.K.; Das, D.

    2010-01-01

    Zn 1-x Fe x O (x = 0.03, 0.05 and 0.07) nanoparticles synthesized by a chemical route were characterized by different techniques. The structural characterization by XRD and TEM confirmed the phase purity of the samples and indicated a reduction in particle size with increase in the dopant (Fe) concentration in ZnO. The optical characterization of the nanoparticles by FTIR, PL and UV-visible spectroscopy confirmed the formation of wurtzite structure and incorporation of Fe in the ZnO lattice. Magnetization measurements by VSM and Faraday balance techniques indicate presence of room temperature ferromagnetism in the Fe-doped ZnO samples. Local environment around the Fe atoms has been probed by 57 Fe Moessbauer spectroscopy and the measured isomer shifts confirmed the charge state of iron as Fe 3+ . Positron annihilation lifetime spectroscopy (PALS) measurements confirm the presence of cation vacancies in the nanoparticles and indicate a reduction of overall defect concentration with incorporation of Fe atoms in the ZnO structure.

  3. Investigation on Fe-doped ZnO nanostructures prepared by a chemical route

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, A.K. [UGC-DAE Consortium for Scientific Research, Kolkata Centre III/LB-8, Bidhannagar, Kolkata 700098 (India); Das, D., E-mail: ddas@alpha.iuc.res.in [UGC-DAE Consortium for Scientific Research, Kolkata Centre III/LB-8, Bidhannagar, Kolkata 700098 (India)

    2010-07-25

    Zn{sub 1-x}Fe{sub x}O (x = 0.03, 0.05 and 0.07) nanoparticles synthesized by a chemical route were characterized by different techniques. The structural characterization by XRD and TEM confirmed the phase purity of the samples and indicated a reduction in particle size with increase in the dopant (Fe) concentration in ZnO. The optical characterization of the nanoparticles by FTIR, PL and UV-visible spectroscopy confirmed the formation of wurtzite structure and incorporation of Fe in the ZnO lattice. Magnetization measurements by VSM and Faraday balance techniques indicate presence of room temperature ferromagnetism in the Fe-doped ZnO samples. Local environment around the Fe atoms has been probed by {sup 57}Fe Moessbauer spectroscopy and the measured isomer shifts confirmed the charge state of iron as Fe{sup 3+}. Positron annihilation lifetime spectroscopy (PALS) measurements confirm the presence of cation vacancies in the nanoparticles and indicate a reduction of overall defect concentration with incorporation of Fe atoms in the ZnO structure.

  4. The challenge of preparation for a chemical, biological, radiological or nuclear terrorist attack

    Directory of Open Access Journals (Sweden)

    Alexander David

    2006-01-01

    Full Text Available Terrorism is not a new phenomenon, but, in the contemporary scene, it has established itself in a manner which commands the most serious attention of the authorities. Until relatively recently, the major threat has been through the medium of conventional weaponry and explosives. Their obvious convenience of use and accessibility guarantees that such methods will continue to represent a serious threat. However, over the last few years, terrorists have displayed an enthusiasm for higher levels of carnage, destruction and publicity. This trend leads inexorably to the conclusion that chemical, biological, radiological and nuclear (CBRN methods will be pursued by terrorist organisations, particularly those which are well organised, are based on immutable ideological principles, and have significant financial backing. Whilst it is important that the authorities and the general public do not risk over-reacting to such a threat (otherwise, they will do the work of the terrorists for them, it would be equally ill-advised to seek comfort in denial. The reality of a CBRN event has to be accepted and, as a consequence, the authorities need to consider (and take seriously how individuals and the community are likely to react thereto and to identify (and rehearse in a realistic climate what steps would need to be taken to ameliorate the effects of such an event.

  5. Investigation on structural and optical properties of ZnO film prepared by simple wet chemical method

    Science.gov (United States)

    Sholehah, Amalia; Mulyadi, Rendi; Haryono, Didied; Muttakin, Imamul; Rusbana, Tb Bahtiar; Mardiyanto

    2018-04-01

    ZnO thin layer has a broad potential application in electronic and optoelectronic devices. In this study, vertically align ZnO layers were deposited on ITO glass using wet chemistry method. The seed layers were prepared using electrodeposition technique at 3°C. The growing process was carried out using chemical bath deposition at 90°C. To improve the structural properties, two different hydrothermal treatment variations were applied separately. From the experiment, it is shown that the hydrothermal process using N2 gas has given the best result, with average diameter, crystallite size, and band-gap energy of 68.83 nm; 56.37 nm; and 3.16 eV, respectively.

  6. Structural and optical properties of Ni-doped CdS thin films prepared by chemical bath deposition method

    Energy Technology Data Exchange (ETDEWEB)

    Premarani, R. [Arumugam Pillai SeethaiAmmal College, Thiruppattur-630211 (India); Saravanakumar, S., E-mail: sarophy84@gmail.com; Chandramohan, R. [SreeSevuganAnnamalai College, Devakottai-630303 (India); Mahalingam, T. [Department of Electrical and Computer Engineering, Ajou University, Suwon 443-749 (Korea, Republic of)

    2015-06-24

    The structural and optical behavior of undoped Cadmiun Sulphide (CdS) and Ni-doped CdS thinfilms prepared by Chemical Bath Deposition (CBD) technique is reported. The crystallite sizes of the thinfilms have been characterized by X-ray diffraction pattern (XRD). The particle sizes increase with the increase of Ni content in the CdS thinfilms. Scanning Electron Microscope (SEM) results indicated that CdS thinfilms is made up of aggregate of spherical-like particles. The composition was estimated by Energy Dispersive Analysis of X-ray (EDX) and reported. Spectroscopic studies revealed considerable improvement in transmission and the band gap of the films changes with addition of Ni dopant that is associated with variation in crystallite sizes in the nano regime.

  7. Anisotropic electrical conduction and reduction in dangling-bond density for polycrystalline Si films prepared by catalytic chemical vapor deposition

    Science.gov (United States)

    Niikura, Chisato; Masuda, Atsushi; Matsumura, Hideki

    1999-07-01

    Polycrystalline Si (poly-Si) films with high crystalline fraction and low dangling-bond density were prepared by catalytic chemical vapor deposition (Cat-CVD), often called hot-wire CVD. Directional anisotropy in electrical conduction, probably due to structural anisotropy, was observed for Cat-CVD poly-Si films. A novel method to separately characterize both crystalline and amorphous phases in poly-Si films using anisotropic electrical conduction was proposed. On the basis of results obtained by the proposed method and electron spin resonance measurements, reduction in dangling-bond density for Cat-CVD poly-Si films was achieved using the condition to make the quality of the included amorphous phase high. The properties of Cat-CVD poly-Si films are found to be promising in solar-cell applications.

  8. Improvement in fatigue property for a PZT ferroelectric film device with SRO electrode film prepared by chemical solution deposition

    International Nuclear Information System (INIS)

    Miyazaki, H.; Miwa, Y.; Suzuki, H.

    2007-01-01

    PZT films with (1 0 0) and (1 1 0) orientation were prepared by spin coating using the chemical solution deposition (CSD) method on an SRO/Si or a Pt/Ti/SiO 2 /Si substrate. The remnant polarization and the saturation polarization of the PZT/SRO/Si film were 21 and 35 μC/cm 2 , and those of the PZT/Pt/Ti/SiO 2 /Si film were 20 and 31 μC/cm 2 . The remnant polarization of the PZT/SRO/Si film maintained more than 10 8 switching cycles, and the fatigue property was observed for the PZT film fabricated on the Pt/Ti/SiO 2 /Si electrode

  9. In situ chemical oxidative polymerization preparation of poly(3,4-ethylenedioxythiophene)/graphene nanocomposites with enhanced thermoelectric performance.

    Science.gov (United States)

    Xu, Kongli; Chen, Guangming; Qiu, Dong

    2015-05-01

    Three different in situ chemical oxidative polymerization routes, that is, (A) spin-coating and subsequent liquid layer polymerization, (B) spin-coating followed by vapor phase polymerization, and (C) in situ polymerization and then post-treatment by immersion in ethylene glycol (EG), have been developed to achieve poly(3,4-ethylenedioxythiophene)/reduced graphene oxide (PEDOT/rGO) nanocomposites. As demonstrated by scanning electron microscopic and energy-dispersive X-ray spectroscopic techniques, PEDOT has been successfully coated on the surface of the rGO nanosheets by each of the three preparation routes. Importantly, all of the nanocomposites display a greatly enhanced thermoelectric performance (power factors) relative to those of the corresponding neat PEDOT. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Passivated graphene transistors fabricated on a millimeter-sized single-crystal graphene film prepared with chemical vapor deposition

    International Nuclear Information System (INIS)

    Lin, Meng-Yu; Lee, Si-Chen; Lin, Shih-Yen; Wang, Cheng-Hung; Chang, Shu-Wei

    2015-01-01

    In this work, we first investigate the effects of partial pressures and flow rates of precursors on the single-crystal graphene growth using chemical vapor depositions on copper foils. These factors are shown to be critical to the growth rate, seeding density and size of graphene single crystals. The prepared graphene films in millimeter sizes are then bubbling transferred to silicon-dioxide/silicon substrates for high-mobility graphene transistor fabrications. After high-temperature annealing and hexamethyldisilazane passivation, the water attachment is removed from the graphene channel. The elimination of uncontrolled doping and enhancement of carrier mobility accompanied by these procedures indicate that they are promising for fabrications of graphene transistors. (paper)

  11. Chemical state and phase structure of (TaNbTiW)N films prepared by combined magnetron sputtering and PBII

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Xingguo [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Tang, Guangze [National Key Laboratory of Materials Behavior and Evaluation in Space Environment, Harbin Institute of Technology, Harbin 150001 (China); Sun, Mingren [National Key Laboratory of Science and Technology on Precision Hot Processing of Metals Harbin Institute of Technology, Harbin Institute of Technology, Harbin 150001 (China); Ma, Xinxin, E-mail: maxin@hit.edu.cn [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Wang, Liqin [School of Mechatronics Engineering, Harbin Institute of Technology, Harbin, 150001 (China)

    2013-09-01

    (TaNbTiW)N films with thickness of ∼1000 nm are prepared on titanium alloy substrate by combined magnetron sputtering deposition and nitrogen plasma based ion implantation (N-PBII). Chemical state of the elements and phase structure of the films are investigated using X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD), respectively. The bonds of Ta-N, Nb-N, Ti-N-O and Ta-O are detected in the (TaNbTiW)N films, however both W-N and W-O are not found. The initial alloy film has a BCC structure, while the films with N-PBII treatment are composed of BCC and FCC structures. The hardness and elastic modulus of the films can be improved by increasing nitrogen implantation dose and reach maximum values of 9.0 GPa and 154.1 GPa, respectively.

  12. Inorganic-organic hybrid polyoxometalate containing supramolecular helical chains: Preparation, characterization and application in chemically bulk-modified electrode

    International Nuclear Information System (INIS)

    Han Zhangang; Zhao Yulong; Peng Jun; Liu Qun; Wang Enbo

    2005-01-01

    An inorganic-organic hybrid polyoxometalate (POM) (Hbpy) 4 [SiMo 12 O 40 ] (1) (bpy = 2,4-bipyridine), has been prepared and characterized. X-ray diffraction study reveals that compound 1 contains interesting organic double helical chains. The hybrid nanoparticles was used as a solid bulkmodifier to fabricate a three-dimensional chemically modified carbon paste electrode (1-CPE) by direct mixing. The electrochemical behavior and electrocatalysis of 1-CPE has been studied in detail. The results indicate that 1-CPE has a good electrocatalytic activity toward the reduction of nitrite in 1 M H 2 SO 4 aqueous solution. 1-CPE shows remarkable stability that can be ascribed to the interactions existed between POM anions and organic double helical bpy chains, which are very important for practical applications in electrode modification

  13. Preparation of rutile TiO(2) coating by thermal chemical vapor deposition for anticoking applications.

    Science.gov (United States)

    Tang, Shiyun; Wang, Jianli; Zhu, Quan; Chen, Yaoqiang; Li, Xiangyuan

    2014-10-08

    To inhibit the metal catalytic coking and improve the oxidation resistance of TiN coating, rutile TiO2 coating has been directly designed as an efficient anticoking coating for n-hexane pyrolysis. TiO2 coatings were prepared on the inner surface of SS304 tubes by a thermal CVD method under varied temperatures from 650 to 900 °C. The rutile TiO2 coating was obtained by annealing the as-deposited TiO2 coating, which is an alternative route for the deposition of rutile TiO2 coating. The morphology, elemental and phase composition of TiO2 coatings were characterized by SEM, EDX and XRD, respectively. The results show that deposition temperature of TiO2 coatings has a strong effect on the morphology and thickness of as-deposited TiO2 coatings. Fe, Cr and Ni at.% of the substrate gradually changes to 0 when the temperature is increased to 800 °C. The thickness of TiO2 coating is more than 6 μm and uniform by metalloscopy, and the films have a nonstoichiometric composition of Ti3O8 when the deposition temperature is above 800 °C. The anticoking tests show that the TiO2 coating at a deposition temperature of 800 °C is sufficiently thick to cover the cracks and gaps on the surface of blank substrate and cut off the catalytic coke growth effect of the metal substrate. The anticoking ratio of TiO2 coating corresponding to each 5 cm segments is above 65% and the average anticoking ratio of TiO2 coating is up to 76%. Thus, the TiO2 coating can provide a very good protective layer to prevent the substrate from severe coking efficiently.

  14. Preparation and physico-chemical study of nitroxide radicals. Isotopic marking with carbon 13 and deuterium

    International Nuclear Information System (INIS)

    Chapelet-Letourneux, G.

    1969-01-01

    N-t-butyl-N-phenyl nitroxide is obtained by: a) action of t-butyl-magnesium chloride on nitrobenzene, or of phenyl-magnesium bromide on nitro-t-butane, b) oxidation of N-t-butyl-N-phenylhydroxylamine, c) oxidation of N-t-butylaniline. In these latter two cases, it has been possible to isolate the pure radical and to study it using UV, IR and EPR. It decomposes to give N-t-butylaniline and the N-oxide of N-t-butyl-p-quinon-imine. The action of peracids such as p-nitro-perbenzoic or m-chloro-perbenzoic acids on amines or hydroxylamines leads to the formation of stable or unstable nitroxide radicals easily observable by EPR. Finally, with a view to obtaining definite values for the coupling between the free electron of a nitroxide and carbon 13, the preparation of such radicals marked with 13 C in the α or β position of the nitroxide function has been carried out. The coupling with an α carbon 13 is negative and does not appear to vary with the spin density on the nitrogen. The interaction with the p nuclei of the nitrogen depends on the nature of the substituents: the two benzyl protons have a hyperfine splitting a H which is always less than that of the ethyl. On the other hand, the 13 C coupling is greater in the first case. The usually adopted conformations for the compounds having the carbonyl group cannot account for the observed values of the β couplings. (author) [fr

  15. Chemical modification of magnetite nanoparticles and preparation of acrylic-base magnetic nanocomposite particles via miniemulsion polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Mahdieh, Athar; Mahdavian, Ali Reza, E-mail: a.mahdavian@ippi.ac.ir; Salehi-Mobarakeh, Hamid

    2017-03-15

    Nowadays, magnetic nanocomposite particles have attracted many interests because of their versatile applications. A new method for chemical modification of Fe{sub 3}O{sub 4} nanoparticles with polymerizable groups is presented here. After synthesis of Fe{sub 3}O{sub 4} nanoparticles by co-precipitation method, they were modified sequentially with 3-aminopropyl triethoxysilane (APTES), acryloyl chloride (AC) and benzoyl chloride (BC) and all were characterized by FTIR, XRD, SEM and TGA analyses. Then the modified magnetite nanoparticles with unsaturated acrylic groups were copolymerized with methyl methacrylate (MMA), butyl acrylate (BA) and acrylic acid (AA) through miniemulsion polymerization. Although several reports exist on preparation of magnetite-base polymer particles, but the efficiency of magnetite encapsulationwith reasonable content and obtaining final stable latexes with limited aggregation ofFe{sub 3}O{sub 4} are still important issues. These were considered here by controlling reaction parameters. Hence, a seriesofmagneticnanocomposites latex particlescontaining different amounts of Fe{sub 3}O{sub 4} nanoparticles (0–10 wt%) were prepared with core-shell morphology and diameter below 200 nm and were characterized by FT-IR, DSC and TGA analyses. Their morphology and size distribution were studied by SEM, TEM and DLS analyses too. Magnetic properties of all products were also measuredby VSM analysis and the results revealed almost superparamagnetic properties for the obtained nanocomposite particles. - Highlights: • Chemical modification of magnetite nanoparticles. • Encapsulation of modified magnetite with acrylic copolymer. • Superparamagnetic Fe3O4/polyacrylic nanocomposite particles.

  16. The preparation and cathodoluminescence of ZnS nanowires grown by chemical vapor deposition

    International Nuclear Information System (INIS)

    Huang, Meng-Wen; Cheng, Yin-Wei; Pan, Ko-Ying; Chang, Chen-Chuan; Shieu, F.S.; Shih, Han C.

    2012-01-01

    Highlights: ► ZnS nanowires have been achieved by thermal evaporation. ► The nanowires were 20–50 nm in diameter and up to tens of nanometers in length. ► Single-crystalline wurtzite and sphalerite ZnS phase are coexist in the nanowires. ► The ZnS nanowires showed almost identical blue luminescence at room temperature. ► ZnS nanowires may be appropriate for use in UV/blue LED phosphor materials. - Abstract: Single crystal ZnS nanowires were successfully synthesized in large quantities on Si (1 0 0) substrates by simple thermal chemical vapor deposition without using any catalyst. The morphology, composition, and crystal structure were characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), and cathodoluminescence (CL) spectroscopy. SEM observations show that the nanowires have diameters about 20–50 nm and lengths up to several tens of micrometers. XRD and TEM results confirmed that the nanowires exhibited both wurtzite and zinc blende structures with growth directions aligned along [0 0 0 2] and [1 1 1], respectively. The CL spectrum revealed emission bands in the UV and blue regions. The blue emissions at 449 and ∼581 nm were attributed to surface states and impurity-related defects of the nanowires, respectively. The perfect crystal structure of the nanowires indicates their potential applications in nanotechnology and in the fabrication of nanodevices.

  17. Effect of protic solvents on CdS thin films prepared by chemical bath deposition

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Pin-Chuan, E-mail: pcyao@mail.dyu.edu.tw; Chen, Chun-Yu

    2015-03-31

    In this study, cadmium sulfide (CdS) thin films are grown on glass substrates by chemical bath deposition (CBD) in an aqueous bath containing 10–20 vol.% alcohol. The roles of ethanol as a protic solvent that substantially improves the quality of films are explored extensively. The deposited films in an alcohol bath are found to be more compact and smoother with smaller CdS grains. The X-ray diffractograms of the samples confirm that all films were polycrystalline with mixed wurtzite (hexagonal) and zinkblende (cubic) phases. Raman spectra indicate that, for a film deposited in an alcohol bath, the position of 1LO is closer to the value for single crystal CdS, indicating that these films have a high degree of crystallinity. The as-deposited CdS thin films in a 10 vol.% alcohol bath were found to have the highest visible transmittance of 81.9%. XPS analysis reveals a stronger signal of C1s for samples deposited in the alcohol baths, indicating that there are more carbonaceous residues on the films with protic solvent than on the films with water. A higher XPS S/Cd atomic ratio for films deposited in an alcohol bath indicates that undesirable surface reactions (leading to sulfur containing compounds other than CdS) occur less frequently over the substrates. - Highlights: • Study of CBD-CdS films grown in an alcohol-containing aqueous bath is reported. • The deposited films in an alcohol bath are more compact with smaller CdS grains. • Raman spectra show that in an alcohol bath, the CdS film has a better crystallinity. • XPS reveals more carbon residues remain on the films deposited using alcohol bath. • In an alcohol bath, the undesirable surface reactions with Cd ions were hindered.

  18. Preparation of Nb3Ge films by chemical transport reaction and their critical properties

    International Nuclear Information System (INIS)

    Oya, G.; Saur, E.J.

    1979-01-01

    Niobium-germanium films have been deposited on sapphire substrates at 900 0 C by a chemical transport reaction method. The highest superconducting transition onset temperature T/sub C,on/ of 22.4K is observed for a nearly stoichiometric Nb 3 Ge film with the A15-type structure (thickness approx.93.5 μm). Lattice constants for the Nb 3 Ge phase formed in the Nb-Ge films with both T/sub C,on/ above 22 K and T/sub C,midpoint/ above 21 K are found to extend from 5.143 to 5.153 A. Deposition rates for the obtained films are in the range of 2-10 μm/min. Critical current densities for the Nb 3 Ge film with the highest T/sub C,on/ value are observed to be relatively low (approx.10 3 A/cm 2 at 19 K at self-field). This is due to the coarse grain structure of the film or the low density of effectual pinning centers in the film. Field variations of the pinning forces operating in this film in magnetic fields both parallel to the film surface and perpendicular to the film surface are found to follow closely b/sup 1/2/ (1-b) 2 , to which the pinning force for flux pinning at the surface of normal regions, such as grain boundaries, film surfaces, etc., is proportional, and where b is the reduced magnetic induction (B/B/sub C2/). A small increase in J/sub C/ at low fields is caused by the presence of a small amount of the Nb 5 Ge 3 phase in a Nb 3 Ge film, and seems attributable to additional flux pinning on Nb 5 Ge 3 -phase particles in the film

  19. Characterization of mesoporous carbon prepared from date stems by H{sub 3}PO{sub 4} chemical activation

    Energy Technology Data Exchange (ETDEWEB)

    Hadoun, H., E-mail: hhadoun@hotmail.com [Nuclear Research Center, 2 Bd Frantz Fanon, Algiers (Algeria); Laboratory of Reaction Genius, Mechanical and Processes Genius Faculty, University of Sciences and Technology Houari – Boumediene, BP n°32, El alia, bab ezzouar, 16111 Algiers (Algeria); Sadaoui, Z. [Laboratory of Reaction Genius, Mechanical and Processes Genius Faculty, University of Sciences and Technology Houari – Boumediene, BP n°32, El alia, bab ezzouar, 16111 Algiers (Algeria); Souami, N.; Sahel, D.; Toumert, I. [Nuclear Research Center, 2 Bd Frantz Fanon, Algiers (Algeria)

    2013-09-01

    The present work was focused on the determination of texture, morphology, crystanillity and oxygenated surface groups characteristics of an activated carbon prepared from date stems. Chemical activation of this precursor at different temperatures (450, 550 and 650 °C) was adopted using phosphoric acid as dehydrating agent at (2/1) impregnation ratio. Fourier transform infrared spectroscopy study was carried out to identify surface groups in date stems activated carbons. The microscopic structure was examined by nitrogen adsorption at 77 K. The interlayer spacing (d{sub 200} and d{sub 100}), stack height (L{sub c}), stack width (L{sub a}) and effective dimension L of the turbostratic crystallites (microcrystallite) in the date stems activated carbons were estimated from X-ray diffraction data (XRD). Results yielded a surface area, S{sub BET}, and total pore volume of 682, 1455, 1319 m{sup 2}/g and 0,343, 1,045 and 0.735 cm{sup 3}/g, for the carbon prepared at 450, 550 and 650 °C, respectively. Scanning electron microscopy exhibits a highly developed porosity which is in good agreement with the porous texture derived from gas adsorption data and these results confirm that the activated carbon is dominated by network of slit-shaped mesopores morphology and in some cases by varied micropores morphologies.

  20. On the structure and surface chemical composition of indium-tin oxide films prepared by long-throw magnetron sputtering

    International Nuclear Information System (INIS)

    Chuang, M.J.; Huang, H.F.; Wen, C.H.; Chu, A.K.

    2010-01-01

    Structures and surface chemical composition of indium tin oxide (ITO) thin films prepared by long-throw radio-frequency magnetron sputtering technique have been investigated. The ITO films were deposited on glass substrates using a 20 cm target-to-substrate distance in a pure argon sputtering environment. X-ray diffraction results showed that an increase in substrate temperature resulted in ITO structure evolution from amorphous to polycrystalline. Field-emission scanning electron microscopy micrographs suggested that the ITO films were free of bombardment of energetic particles since the microstructures of the films exhibited a smaller grain size and no sub-grain boundary could be observed. The surface composition of the ITO films was characterized by X-ray photoelectron spectroscopy (XPS). Oxygen atoms in both amorphous and crystalline ITO structures were observed from O 1 s XPS spectra. However, the peak of the oxygen atoms in amorphous ITO phase could only be found in samples prepared at low substrate temperatures. Its relative peak area decreased drastically when substrate temperatures were larger than 200 o C. In addition, a composition analysis from the XPS results revealed that the films deposited at low substrate temperatures contained high concentration of oxygen at the film surfaces. The oxygen-rich surfaces can be attributed to hydrolysis reactions of indium oxides, especially when large amount of the amorphous ITO were developed near the film surfaces.

  1. Evaluation of the effect of conventionally prepared swarna makshika bhasma on different bio-chemical parameters in experimental animals

    Directory of Open Access Journals (Sweden)

    Sudhaldev Mohapatra

    2011-01-01

    Full Text Available Swarna makshika (chalcopyrite bhasma (SMB has been used for different therapeutic purposes since long in Ayurveda. The present study is conducted to evaluate the effect of conventionally prepared SMB on different bio-chemical parameters in experimental animals, for providing scientific data base for its logical use in clinical practice. The genuine SMB was prepared by following classical techniques of shodhana and marana most commonly used by different Ayurvedic drug manufacturers. Shodhana was done by roasting raw swarna makshika with lemon juice for three days and marana was performed by 11 putas . The experimental animals (rats were divided into two groups. SMB mixed with diluted honey was administered orally in therapeutic dose to Group SMB and diluted honey only was administered to vehicle control Group, for 30 days. The blood samples were collected twice, after 15 days and after 30 days of drug administration and different biochemical investigations were done. Biochemical parameters were chosen based on references from Ayurvedic classics and contemporary medicine. It was observed that Hb% was found significantly increased and LDL and VLDL were found significantly decreased in Group SMB when compared with vehicle control group. This experimental data will help the clinician for the logical use of SMB in different disease conditions with findings like low Hb% and high LDL, VLDL levels.

  2. Physico-chemical properties of the new generation IV iron preparations ferumoxytol, iron isomaltoside 1000 and ferric carboxymaltose.

    Science.gov (United States)

    Neiser, Susann; Rentsch, Daniel; Dippon, Urs; Kappler, Andreas; Weidler, Peter G; Göttlicher, Jörg; Steininger, Ralph; Wilhelm, Maria; Braitsch, Michaela; Funk, Felix; Philipp, Erik; Burckhardt, Susanna

    2015-08-01

    The advantage of the new generation IV iron preparations ferric carboxymaltose (FCM), ferumoxytol (FMX), and iron isomaltoside 1000 (IIM) is that they can be administered in relatively high doses in a short period of time. We investigated the physico-chemical properties of these preparations and compared them with those of the older preparations iron sucrose (IS), sodium ferric gluconate (SFG), and low molecular weight iron dextran (LMWID). Mössbauer spectroscopy, X-ray diffraction, and Fe K-edge X-ray absorption near edge structure spectroscopy indicated akaganeite structures (β-FeOOH) for the cores of FCM, IIM and IS, and a maghemite (γ-Fe2O3) structure for that of FMX. Nuclear magnetic resonance studies confirmed the structure of the carbohydrate of FMX as a reduced, carboxymethylated, low molecular weight dextran, and that of IIM as a reduced Dextran 1000. Polarography yielded significantly different fingerprints of the investigated compounds. Reductive degradation kinetics of FMX was faster than that of FCM and IIM, which is in contrast to the high stability of FMX towards acid degradation. The labile iron content, i.e. the amount of iron that is only weakly bound in the polynuclear iron core, was assessed by a qualitative test that confirmed decreasing labile iron contents in the order SFG ≈ IS > LMWID ≥ FMX ≈ IIM ≈ FCM. The presented data are a step forward in the characterization of these non-biological complex drugs, which is a prerequisite to understand their cellular uptake mechanisms and the relationship between the structure and physiological safety as well as efficacy of these complexes.

  3. Effect of gamma irradiation on the microbial load, Chemical and sensory properties of borak : Prepared chilled meals

    International Nuclear Information System (INIS)

    Al-Bachir, M.

    2007-01-01

    Locally prepared meals, borak, were treated with 0, 2, 4 and 6 kGy doses of gamma irradiation. Treated and untreated borak were kept in a refrigerator (1-4 Centigrade). Microbiological and chemical analyses were performed on each treated sample immediately after processing, and weekly throughout storage period which lasted for 6 weeks. Sensory evaluation and proximate analysis were done within one week after irradiation. Results of the proximate analysis of borak showed that irradiation doses did not have a significant effect on moisture, protein and fat content of borak. Gamma irradiation decreased the total counts of mesophilic aerobic bacteria, total coliform and yeat and increased the shelf-life of borak. The radiation doses required to reduce the microorganisms load one log cycle (D 1 0) in borak were 456 and 51- Gy for the Salmonella spp and E. coli, respectively: The three chemical parameters, total acidity, lipid peroxide and volatile basic nitrogen, which were chosen as the indices of freshness, were all well within the acceptable limits for up to 1, 3 and 6 weeks at 1-4 Centigrade for samples treated with 2, 4 and 6 kGy, respectively. Sensory evaluation showed no significant differences between irradiated and non-irradiated samples. (author)

  4. Synthesis and characterization of graphene layers prepared by low-pressure chemical vapor deposition using triphenylphosphine as precursor

    Energy Technology Data Exchange (ETDEWEB)

    Mastrapa, G.C.; Maia da Costa, M.E.H. Maia [Departamento de Física, Pontifícia Universidade Católica do Rio de Janeiro, 22451-900, Rio de Janeiro, RJ (Brazil); Larrude, D.G., E-mail: dunigl@vdg.fis.puc-rio.br [Departamento de Física, Pontifícia Universidade Católica do Rio de Janeiro, 22451-900, Rio de Janeiro, RJ (Brazil); Freire, F.L. [Departamento de Física, Pontifícia Universidade Católica do Rio de Janeiro, 22451-900, Rio de Janeiro, RJ (Brazil); Brazilian Center for Physical Research, 22290-180, Rio de Janeiro, RJ (Brazil)

    2015-09-15

    The synthesis of a single-layer graphene using a low-pressure Chemical Vapor Deposition (CVD) system with triphenylphosphine as precursor is reported. The amount of triphenylphosphine used as precursor was in the range of 10–40 mg. Raman spectroscopy was employed to analyze samples prepared with 10 mg of the precursor, and these spectra were found typical of graphene. The Raman measurements indicate that the progressive degradation of graphene occurs as the amount of triphenylphosphine increases. X-ray photoelectron spectroscopy measurements were performed to investigate the different chemical environments involving carbon and phosphorous atoms. Scanning electron microscopy and transmission electron microscopy were also employed and the results reveal the formation of dispersed nanostructures on top of the graphene layer, In addition, the number of these nanostructures is directly related to the amount of precursor used for sample growth. - Highlights: • We grow graphene using the solid precursor triphenylphosphine. • Raman analysis confirms the presence of monolayer graphene. • SEM images show the presence of small dark areas dispersed on the graphene surface. • Raman I{sub D}/I{sub G} ratio increases in the dark region of the graphene surface.

  5. Effect of Gamma Radiation on Microbial load, Chemical and Sensory Properties of Sheesh Tawoq, Prepared Chilled Meal

    International Nuclear Information System (INIS)

    Al-Bachir, M.

    2011-01-01

    Locally prepared meal Sheesh Tawoq was treated with 0, 2, 4 or 6 kGy doses of gamma irradiation. Treated and untreated Sheesh Tawoq were kept in a refrigerator (1 and 4 mC). Microbiological, chemical and sensory characteristics of Sheesh Tawoq were evaluated at 0, 4, 8, 12, 16 and 20th week of storage. The results indicate that 4 and 6 kGy doses of gamma irradiation decreased the total counts of mesophilic aerobic bacteria, total coliform and yeast. Thus the microbiological shelf-life of Sheesh Tawoq was significantly extended from 12 weeks (control) to more than 20 weeks (samples treated with 4 or 6 kGy). Irradiation doses did not have a significant effect on the major constituents of Sheesh Tawoq (moisture, protein and fats). The radiation doses required to reduce the microorganisms load one log cycle (D 1 0 ) in Sheesh Tawoq were 435 and 385 Gy for the Salmonella and E. coli , respectively. The chemical parameters, total acidity and volatile basic nitrogen, which were chosen as the indices of freshness, were all well within the acceptable limit for up to 12 weeks for Sheesh Tawoq treated with 0 and 2 kGy, and for up to 20 weeks at 1 and 4 mC for samples treated with 4 and 6 kGy. Sensory evaluation showed no significant differences between irradiated and non-irradiated samples. (author)

  6. CHEMICALS

    CERN Multimedia

    Medical Service

    2002-01-01

    It is reminded that all persons who use chemicals must inform CERN's Chemistry Service (TIS-GS-GC) and the CERN Medical Service (TIS-ME). Information concerning their toxicity or other hazards as well as the necessary individual and collective protection measures will be provided by these two services. Users must be in possession of a material safety data sheet (MSDS) for each chemical used. These can be obtained by one of several means : the manufacturer of the chemical (legally obliged to supply an MSDS for each chemical delivered) ; CERN's Chemistry Service of the General Safety Group of TIS ; for chemicals and gases available in the CERN Stores the MSDS has been made available via EDH either in pdf format or else via a link to the supplier's web site. Training courses in chemical safety are available for registration via HR-TD. CERN Medical Service : TIS-ME :73186 or service.medical@cern.ch Chemistry Service : TIS-GS-GC : 78546

  7. Ion chromatographic analysis of high specific activity 18FDG preparations and detection of the chemical impurity 2-deoxy-2-chloro-D-glucose

    International Nuclear Information System (INIS)

    Alexoff, D.L.; Casati, R.; Fowler, J.S.; Wolf, A.P.; Shea, C.; Schlyer, D.J.; Chyng-Yann Shiue

    1992-01-01

    Because of the widespread use of 2-deoxy-2-[ 18 F]fluoro-D-glucose(FDG) prepared by the ''Julich'' method or its variants it was decided necessary to determine the major chemical impurities present in the final product. An analytical system for quantifying FDG was developed using pulsed amperometry after separation by high-performance anion exchange chromotography. With this system a heretofore unidentified impurity, 2-deoxy-2-chloro-D-glucose(C1DG) was found in our preparation and in those from other laboratories using the ''Julich'' method. C1DG arises from C1 - ion displacement during the labeling procedure where C1 - ion comes from several sources, and C1 - ion displacement from the HC1 used in the hydrolysis step. FDG mass was present in the same preparations at a level of ca 1-40 μg. Other major chemical constituents were glucose (ca 1-6 mg) and mannose (ca 10-18 μg). Glycerol, arising from sterilizing filters, was also detected in most preparations. Although C1DG is a chemical impurity which has not been detected previously in nca FDG preparations, its biochemical and pharmacological properties are similar to FDG and 2-deoxy-D-glucose. Thus it is unlikely that the presence of small quantities of C1DG found in typical FDG preparations (ca 100 μg) would have adverse pharmacological or toxicological consequences that would limit continued application of this radiopharmaceutical in basic and clinical studies. (Author)

  8. Effect of gamma irradiation on the microbial load and chemical and sensory properties of locally prepared fast meals

    International Nuclear Information System (INIS)

    Al-Bachir, M.

    2009-01-01

    Locally prepared meals (kubba, borak, cheese borak and sheesh tawoq) were treated with 2, 4 or 6 kGy doses of gamma irradiation. Treated and untreated samples were kept in a refrigerator (1-4 deg. C). Microbiological and chemical analyses were performed on each treated sample immediately after processing, and weekly throughout the storage period, which lasted for 3 weeks for kubba, 6 weeks for borak and cheese borak and 20 weeks for sheesh tawoq. Sensory evaluation and proximate analysis were done within one week after irradiation. Results of the proximate analysis of borak, cheese borak and sheesh tawoq showed that the irradiation doses did not have a significant effect on the moisture, protein and fat contents of meals, whereas for kubba, irradiation decreased the moisture, protein and fat contents. The doses of gamma irradiation selected decreased the microorganism load and increased the shelf life of all meals studied. The radiation doses required to reduce Salmonella and Escherichia coli by one log cycle (D 10 ) in borak were 0.46 and 0.51 kGy, in cheese borak 0.30 and 0.50 kGy and for sheesh tawoq 0.44 and 0.39 kGy, respectively. The three chemical parameters, total acidity, lipid peroxide and volatile basic nitrogen, which were chosen as the indices of freshness, were all well within the acceptable limit for up to 3 weeks for kubba, 6 weeks for borak and cheese borak and 20 weeks for sheesh tawoq treated with 6 kGy. Sensory evaluation showed no significant differences between irradiated and non-irradiated samples. (author)

  9. Microstructure, chemical states, and mechanical properties of V–C–Co coatings prepared by non-reactive magnetron sputtering

    International Nuclear Information System (INIS)

    Zhang, Xiaojuan; Wang, Bo; Zhan, Zhaolin; Huang, Feng

    2013-01-01

    V–C–Co coatings have been prepared by non-reactive magnetron co-sputtering from VC and Co targets. The microstructure, chemical states, and mechanical properties are examined as a function of Co content in the coatings. The coatings are dense, with columnar growth structures. High resolution transmission electron microscopy (HRTEM) studies identify a nanocomposite microstructure for the 12.4 at.% Co coating, in which ligament-like Co-rich regions partially separate the nanocrystalline VC grains. X-ray photoelectron spectroscopy studies reveal a noticeable charge transfer from Co 2p states to C 1s states. This charge transfer, in addition to the ligament-like Co-rich regions as revealed by HRTEM, points to the formation of a strong Co/VC interface. The nanoindentation hardness of the coatings drops steadily with the Co content, from 29 GPa for pure VC to ∼ 21 GPa for the 12.4 at.% Co coating. Meanwhile, the plasticity characteristic increased from 0.42 to 0.53. - Highlights: • Nanocomposite V–C–Co coatings with strong Co/VC interfaces were formed. • Found nanocrystalline VC grains separated by ∼ 1 nm thin Co-rich ligaments. • A noticeable amount of C-Co bonds between VC and Co is identified. • V–C–Co coatings exhibited a higher plasticity characteristic than VC

  10. Microstructure, chemical states, and mechanical properties of V–C–Co coatings prepared by non-reactive magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiaojuan [Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201 (China); School of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650000 (China); Wang, Bo [Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201 (China); Zhan, Zhaolin [School of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650000 (China); Huang, Feng, E-mail: huangfeng@nimte.ac.cn [Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201 (China)

    2013-07-01

    V–C–Co coatings have been prepared by non-reactive magnetron co-sputtering from VC and Co targets. The microstructure, chemical states, and mechanical properties are examined as a function of Co content in the coatings. The coatings are dense, with columnar growth structures. High resolution transmission electron microscopy (HRTEM) studies identify a nanocomposite microstructure for the 12.4 at.% Co coating, in which ligament-like Co-rich regions partially separate the nanocrystalline VC grains. X-ray photoelectron spectroscopy studies reveal a noticeable charge transfer from Co 2p states to C 1s states. This charge transfer, in addition to the ligament-like Co-rich regions as revealed by HRTEM, points to the formation of a strong Co/VC interface. The nanoindentation hardness of the coatings drops steadily with the Co content, from 29 GPa for pure VC to ∼ 21 GPa for the 12.4 at.% Co coating. Meanwhile, the plasticity characteristic increased from 0.42 to 0.53. - Highlights: • Nanocomposite V–C–Co coatings with strong Co/VC interfaces were formed. • Found nanocrystalline VC grains separated by ∼ 1 nm thin Co-rich ligaments. • A noticeable amount of C-Co bonds between VC and Co is identified. • V–C–Co coatings exhibited a higher plasticity characteristic than VC.

  11. Enhancement of C/C-LAS joint using aligned carbon nanotubes prepared by injection chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Feng-Ling; Fu, Qian-Gang, E-mail: fuqiangang@nwpu.edu.cn; Feng, Lei; Shen, Qing-Liang

    2016-01-05

    Carbon nanotubes (CNTs) enhanced carbon/carbon-lithium aluminum silicate (C/C-LAS) joint was prepared by a three-step technique of pack cementation, injection chemical vapor deposition (ICVD) and hot-pressing. A layer of aligned CNTs was grown on the surface of SiC coated C/C composites by ICVD method, and the joint was obtained by hot-pressing with magnesium aluminum silicate (MAS) as the interlayer. SEM observation reveals that the introduced CNTs result in the formation of a dense and crack-free CNT/MAS nanocomposite interface between SiC and MAS. Compared with the joints without CNTs, the average shear strength of the joints reinforced by CNTs was improved by 48% accompanied by an obvious change in failure mode from brittle fracture without CNTs to plastic fracture with CNTs. The pulling-out and bridging of CNTs on the fracture surfaces had a positive effect on the strength enhancement of the C/C-LAS joint.

  12. Characterization of electro-conductive fabrics prepared by in situ chemical and electrochemical polymerization of pyrrole onto polyester fabric

    Energy Technology Data Exchange (ETDEWEB)

    Maiti, Syamal; Das, Dipayan; Sen, Kushal, E-mail: kushal@textile.iitd.ernet.in

    2014-09-15

    Highlights: • Surface resistivity of the fabrics decreased rapidly with an increase in add-on. • Add-on and resistivity were not correlated below a resistivity value of about 200 Ω. • Higher add-on but lower surface roughness resulted in lower surface resistivity. • The voltage–current and voltage–temperature behaviours were found to be non-linear. • Electro-conductive fabric exhibited 98% electromagnetic shielding efficiency. - Abstract: This paper reports a study on electro-conductive fabrics prepared by a combined in situ chemical and electrochemical polymerization of pyrrole. Specific observations are made to establish the roles of add-on and surface roughness on the surface resistivity of the electro-conductive fabrics. The performance characteristics of the fabrics are reported in terms of electrical conductivity, voltage–current and voltage–temperature characteristics and electromagnetic interference (EMI) shielding capability. The surface resistivity of the fabric was found to be as low as 11.79 Ω. The voltage–current profile of the fabric is observed to be non-ohmic as well as the voltage–temperature curve is found to be exponential. The EMI shielding efficiency of the fabric was found to be about 98%.

  13. THE CHEMICAL COMPOSITION AND VARIOUS SAMPLES PREPARATION METHODS FOR In Vitro GAS TEST OF TWO TROPICAL FEEDS

    Directory of Open Access Journals (Sweden)

    J. Daryatmo

    2015-04-01

    Full Text Available A 3x2 factorial experimental design was conducted to evaluate the chemical composition ofSesbania grandiflora (SG and Manihot esculenta Crantz (MEC leaves and to measure the effects ofpreparation and drying methods on the in vitro gas production in the presence and absence of PEG. Thecollected samples were divided into three groups: One group was fresh samples (F. The second groupwas oven-dried at 55°C for 48h (OD and the last group was freeze-dried at –40°C for 72h (FD. Resultsshowed that the mean value of gas production from fresh SG and MEC samples were not significantlyhigher (P<0.05 than from FD and OD samples. In SG and MEC, the mean value of gas production ofFD was not significant compared to OD samples (P>0.05. Gas production from samples added withPEG were higher (P<0.05 than without PEG. In conclusion, the preparation and drying methods of feedsamples could affect the volume of gas production. The addition of PEG in SG and MEC resulted inhigher gas production volumes.

  14. Fabrication of a methanol chemical sensor based on hydrothermally prepared α-Fe₂O₃ codoped SnO₂ nanocubes.

    Science.gov (United States)

    Rahman, Mohammed M; Khan, Sher Bahadar; Jamal, A; Faisal, M; Asiri, Abdullah M

    2012-06-15

    We have prepared calcined α-Fe(2)O(3) codoped SnO(2) nanocubes (NCs) by a hydrothermal method using reducing agents in alkaline medium. The codoped NCs were characterized by UV/vis, FT-IR, and Raman spectroscopy, powder X-ray diffraction (XRD), and field-emission scanning electron microscopy (FESEM). They were deposited on a silver electrode (AgE, surface area, 0.0216 cm(2)) to give a sensor with a fast response towards methanol in liquid phase. The sensor also exhibits good sensitivity and long-term stability, and enhanced electrochemical response. The calibration plot is linear (r(2)=0.9809) over the 0.25 mmol L(-1) to 0.25 mol L(-1) methanol concentration range. The sensitivity is ∼5.79 μA cm(-2)mM(-1), and the detection limit is 0.16 ± 0.02 mmol L(-1) (signal-to-noise ratio, at a SNR of 3). We also discuss possible future prospective uses of this codoped semiconductor nanomaterial in terms of chemical sensing. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. TiO2 based photo-catalysts prepared by chemical vapor infiltration (CVI) on micro-fibrous substrates

    International Nuclear Information System (INIS)

    Sarantopoulos, Ch.

    2007-10-01

    This thesis deals with micro-fibrous glass substrates functionalized with TiO 2 . The oxide is deposited as a thin film onto the micro fibres by chemical vapour infiltration (CVI), yielding a photo-catalytic material usable for cleaning polluted air. We studied the relation between the structure of the material and its photo-catalytic efficiency. TiO 2 thin films were prepared at low pressure, in a hot-wall CVD reactor, using Ti(O-iPr) 4 as a precursor. They were characterized by XRD, SEM, EDX, XPS and BET, and by recording the kinetics of decomposition of varied pollutants in solution (orange G, malic acid, imazapyr) and in air (toluene). The conditions favoring the growth of porous films through a columnar growth mode were established by MOCVD-depositing TiO 2 thin films on flat substrates. The subsequent works with micro fibrous thick substrates showed the uniformity of infiltration to be the main factor governing the photo-catalytic efficiency. Operating parameters that optimize infiltration do not yield columnar growth mode. A compromise is necessary. Our photo-catalysts are showing high efficiency comparable, if not higher, to those actually commercialized. These promising results are opening real perspectives for the proposed process. (author)

  16. Characterization of electro-conductive fabrics prepared by in situ chemical and electrochemical polymerization of pyrrole onto polyester fabric

    International Nuclear Information System (INIS)

    Maiti, Syamal; Das, Dipayan; Sen, Kushal

    2014-01-01

    Highlights: • Surface resistivity of the fabrics decreased rapidly with an increase in add-on. • Add-on and resistivity were not correlated below a resistivity value of about 200 Ω. • Higher add-on but lower surface roughness resulted in lower surface resistivity. • The voltage–current and voltage–temperature behaviours were found to be non-linear. • Electro-conductive fabric exhibited 98% electromagnetic shielding efficiency. - Abstract: This paper reports a study on electro-conductive fabrics prepared by a combined in situ chemical and electrochemical polymerization of pyrrole. Specific observations are made to establish the roles of add-on and surface roughness on the surface resistivity of the electro-conductive fabrics. The performance characteristics of the fabrics are reported in terms of electrical conductivity, voltage–current and voltage–temperature characteristics and electromagnetic interference (EMI) shielding capability. The surface resistivity of the fabric was found to be as low as 11.79 Ω. The voltage–current profile of the fabric is observed to be non-ohmic as well as the voltage–temperature curve is found to be exponential. The EMI shielding efficiency of the fabric was found to be about 98%

  17. Structural, optical and electrical properties of CuInS{sub 2} thin films prepared by chemical spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Terasako, Tomoaki; Uno, Yuji; Inoue, Seiki; Shirakata, Sho [Faculty of Engineering, Ehime University, 3 Bunkyo-cho, Matsuyama 780-8577 (Japan); Kariya, Tetsuya [Faculty of Science, Kochi University, Akebono-cho, Kochi, 780-8072 (Japan)

    2006-09-15

    Polycrystalline CuInS{sub 2} thin films were prepared by chemical spray pyrolisis (CSP) on glass substrate from the ethanol aqueous solution containing CuCl{sub 2}, InCl{sub 3} and thiourea. Structural, electrical and optical properties were systematically studied in terms of substrate temperature, pH and the ion ratio (Cu/In) of the spray solution. Although the In-rich films were composed of CuInS{sub 2} and In{sub 2}S{sub 3}, the In{sub 2}S{sub 3} content in the film decreased with Cu/In ratio. Appearance of Raman peaks at 288 and 298 cm{sup -1} indicated that the films contained CuInS{sub 2} with chalcopyrite and CuAu phases. Typical grain size in the Cu-rich films was 200 nm. Optical gap energies were approximately 0.1-0.2eV smaller than the bandgap energy of the CuInS{sub 2} bulk crystal. Resistivity of the Cu-rich films without In{sub 2}S{sub 3} secondary phase was 0.2-5 {omega}cm. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. Decontamination in preparation for dismantlement - AREVA's chemical decontamination technologies, projects performed and results obtained in the period 2011-2016

    International Nuclear Information System (INIS)

    Topf, C.; Sempere Belda, L.

    2017-01-01

    As a consequence of the nuclear phase-out decreed by the German government, several nuclear power plants in the country have already ceased operation. The remaining ones will cease operation by 2022. This has turned Germany into one of the most active regions worldwide in the field of nuclear decommissioning, with new and emerging technologies being deployed on the field, and already preexisting technologies being put to the test, optimized and developed into full maturity. The chemistry services division of AREVA GmbH has already performed 5 Full System Decontaminations (FSD) in preparation for decommissioning in this period - three in PWRs and two in BWRs - along with other international projects of relevance for decommissioning operations. During a FSD, the complete primary circuit of a nuclear power plant including auxiliary systems is subject to a chemical treatment; designed to remove radioactive matter accumulated onto system surfaces during operation. Through the effective removal of this radioactive accumulations contact dose rates on the different components of the primary circuit can be consistently reduced by factors larger than 50. This results in much lower ambient dose rates and, hence, in very significant dose savings for subsequent decommissioning activities. Additionally, dismantlement operations of large components are considerably simplified and can be performed under conditions that wouldn't have been possible before. The project specific objectives and challenges, the technologies employed, and the results obtained are presented and commented here. (authors)

  19. Possible preparation of wood-plastic composites based on unsaturated polyester resins and styrene by radiation and chemical methods in combination

    International Nuclear Information System (INIS)

    Pesek, M.; Pultar, F.; Jarkovsky, J.; Andr, J.

    1983-01-01

    Using the radiation chemical method it is possible to prepare wood-plastic composites using doses of 1 to 2.5 kGy. The impregnation mixture in the wood gelatinates and subsequent curing using chemical initiators takes place without outflow of the mixture from the wood and without formation of incrustations. The basic components of the impregnation mixtures used were unsaturated polyester resins; styrene or methyl methacrylate was used as the thinner. The proven initiator of polymerization was 2,2'-azobisisobutyronitrile. The technology is described of wood impregnation and radiation or chemical curing. The effects were monitored of viscosity, temperature, radiation dose and the concentrations of the individual components of the impregnation mixtures and initiators of polymerization on the process of the preparation of wood-plastic composites. (M.D.)

  20. Chemical approach to solvent removal during nanoencapsulation: its application to preparation of PLGA nanoparticles with non-halogenated solvent

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Youngme [Ewha Womans University, College of Pharmacy (Korea, Republic of); Sah, Eric [University of Notre Dame, College of Science (United States); Sah, Hongkee, E-mail: hsah@ewha.ac.kr [Ewha Womans University, College of Pharmacy (Korea, Republic of)

    2015-11-15

    The objective of this study was to develop a new oil-in-water emulsion-based nanoencapsulation method for the preparation of PLGA nanoparticles using a non-halogenated solvent. PLGA (60–150 mg) was dissolved in 3 ml of methyl propionate, which was vortexed with 4 ml of a 0.5–4 % polyvinyl alcohol solution. This premix was sonicated for 2 min, added into 30 ml of the aqueous polyvinyl alcohol solution, and reacted with 3 ml of 10 N NaOH. Solvent removal was achieved by the alkaline hydrolysis of methyl propionate dissolved in an aqueous phase into water-soluble methanol and sodium propionate. It was a simple but effective technique to quickly harden nanoemulsion droplets into nanoparticles. The appearing PLGA nanoparticles were recovered by ultracentrifugation and/or dialysis, lyophilized with trehalose, and redispersed by water. This nanoencapsulation technique permitted a control of their mean diameters over 151.7 ± 3.8 to 440.2 ± 22.2 nm at mild processing conditions. When the aqueous polyvinyl alcohol concentration was set at ≥1 %, nanoparticles showed uniform distributions with polydispersity indices below 0.1. There were no significant changes in their mean diameters and size distribution patterns before and after lyophilization. When mestranol was encapsulated into nanoparticles, the drug was completely nanoencapsulated: depending on experimental conditions, their encapsulation efficiencies were determined to be 99.4 ± 7.2 to 105.8 ± 6.3 %. This simple, facile nanoencapsulation technique might have versatile applications for the preparation of polymeric nanoparticulate dosage forms.Graphical AbstractSchematic illustration of an innovative chemical approach to solvent removal during nanoencapsulation. Methyl propionate present in the aqueous continuous phase reacts with sodium hydroxide, thereby producing methanol and sodium propionate. Its alkaline hydrolysis allows the continuous extraction of the solvent out of nanoemulsion

  1. Chemical approach to solvent removal during nanoencapsulation: its application to preparation of PLGA nanoparticles with non-halogenated solvent

    International Nuclear Information System (INIS)

    Lee, Youngme; Sah, Eric; Sah, Hongkee

    2015-01-01

    The objective of this study was to develop a new oil-in-water emulsion-based nanoencapsulation method for the preparation of PLGA nanoparticles using a non-halogenated solvent. PLGA (60–150 mg) was dissolved in 3 ml of methyl propionate, which was vortexed with 4 ml of a 0.5–4 % polyvinyl alcohol solution. This premix was sonicated for 2 min, added into 30 ml of the aqueous polyvinyl alcohol solution, and reacted with 3 ml of 10 N NaOH. Solvent removal was achieved by the alkaline hydrolysis of methyl propionate dissolved in an aqueous phase into water-soluble methanol and sodium propionate. It was a simple but effective technique to quickly harden nanoemulsion droplets into nanoparticles. The appearing PLGA nanoparticles were recovered by ultracentrifugation and/or dialysis, lyophilized with trehalose, and redispersed by water. This nanoencapsulation technique permitted a control of their mean diameters over 151.7 ± 3.8 to 440.2 ± 22.2 nm at mild processing conditions. When the aqueous polyvinyl alcohol concentration was set at ≥1 %, nanoparticles showed uniform distributions with polydispersity indices below 0.1. There were no significant changes in their mean diameters and size distribution patterns before and after lyophilization. When mestranol was encapsulated into nanoparticles, the drug was completely nanoencapsulated: depending on experimental conditions, their encapsulation efficiencies were determined to be 99.4 ± 7.2 to 105.8 ± 6.3 %. This simple, facile nanoencapsulation technique might have versatile applications for the preparation of polymeric nanoparticulate dosage forms.Graphical AbstractSchematic illustration of an innovative chemical approach to solvent removal during nanoencapsulation. Methyl propionate present in the aqueous continuous phase reacts with sodium hydroxide, thereby producing methanol and sodium propionate. Its alkaline hydrolysis allows the continuous extraction of the solvent out of nanoemulsion

  2. YBa{sub 2}Cu{sub 3}O{sub 7-x} thin films prepared by chemical solution deposition

    Energy Technology Data Exchange (ETDEWEB)

    Apetrii, Claudia

    2009-11-25

    The discovery of superconductivity in ceramic materials by Bednorz and Mueller in early 1987, immediately followed by Wu et al., who showed that YBa{sub 2}Cu{sub 3}O{sub 7-x} (YBCO) becomes superconducting (92 K) well above the boiling point of nitrogen (77 K) created a great excitement in superconductivity research. Potential applications of high T{sub c}-superconductors require large critical currents and high-applied magnetic fields. Effective ways to increase the critical current density at high magnetic fields in YBCO are the introduction of nanoparticles and chemical substitution of yttrium by other rare earth elements. Since low costs and environmental compatibility are essential conditions for the preparation of long length YBCO films, the cost effective chemical solution deposition (CSD) procedure was selected, given that no vacuum technology is required. To reveal the flexibility and the good optimization possibilities of the CSD approach two main processes were chosen for comparison: a fluorine-free method, namely the polymer-metal precursor technique, and a fluorine-based method, the metalorganic deposition (MOD) using the trifluoroacetates (TFA) technique. Sharp transition temperature widths {delta}T{sub c} of 1.1 K for the polymer metal method, 0.8 K for TFA method and critical current densities J{sub c} of {approx}3.5 MA/cm{sup 2} shows that high quality YBCO thin films can be produced using both techniques. Especially interesting is the magnetic field dependence of the critical current density J{sub c}(B) of the Y(Dy)BCO (80 %) films showing that for the lower magnetic fields the critical current density J{sub c}(B) is higher for a standard YBCO film, but at fields higher than 4.5 T the critical current density J{sub c}(B) of Y(Dy)BCO is larger than that for the YBCO. Above 8 T, J{sub c}(B) of the Y(Dy)BCO film is more than one order of magnitude higher than in pure YBCO film. (orig.)

  3. Antimicrobial activity of novel nanostructured Cu-SiO2 coatings prepared by chemical vapour deposition against hospital related pathogens.

    Science.gov (United States)

    Varghese, Sajnu; Elfakhri, Souad O; Sheel, David W; Sheel, Paul; Bolton, Frederick J Eric; Foster, Howard A

    2013-09-05

    There is increasing recognition that the healthcare environment acts as an important reservoir for transmission of healthcare acquired infections (HCAI). One method of reducing environmental contamination would be use of antimicrobial materials. The antimicrobial activity of thin silica-copper films prepared by chemical vapour deposition was evaluated against standard strains of bacteria used for disinfectant testing and bacteria of current interest in HCAI. The structure of the coatings was determined using Scanning Electron Microscopy and their hardness and adhesion to the substrate determined. Antimicrobial activity was tested using a method based on BS ISO 22196:2007. The coatings had a pale green-brown colour and had a similar hardness to steel. SEM showed nano-structured aggregates of Cu within a silica matrix. A log10 reduction in viability of >5 could be obtained within 4 h for the disinfectant test strains and within 6 h for producing Acinetobacter baumannii, Klebsiella pneumoniae and Stenotrophomonas maltophilia. Activity against the other hospital isolates was slower but still gave log10 reduction factors of >5 for extended spectrum β-lactamase producing Escherichia coli and >3 for vancomycin resistant Enterococcus faecium, methicillin resistant Staphylococcus aureus and Pseudomonas aeruginosa within 24 h. The results demonstrate the importance of testing antimicrobial materials destined for healthcare use against isolates of current interest in hospitals as well as standard test strains. The coatings used here can also be applied to substrates such as metals and ceramics and have potential applications where reduction of microbial environmental contamination is desirable.

  4. Testing REACH draft technical guidance notes for conducting chemical safety assessments-the experience of a downstream user of a preparation.

    Science.gov (United States)

    Gade, Anne Lill; Ovrebø, Steinar; Hylland, Ketil

    2008-07-01

    The goal of REACH is the safe use of chemicals. This study examines the efficiency and usefulness of two draft technical guidance notes in the REACH Interim Project 3.2-2 for the development of the chemical safety report and exposure scenarios. A case study was carried out for a paint system for protection of structural steel. The focuses of the study were risk assessment of preparations based on Derived No Effect Level (DNEL) and Predicted No Effect Concentrations (PNEC) and on effective and accurate communication in the supply chain. Exposure scenarios and generic descriptions of uses, risk management measures, and exposure determinants were developed. The study showed that communication formats, software tools, and guidelines for chemical risk assessment need further adjustment to preparations and real-life situations. Web platforms may simplify such communication. The downstream formulator needs basic substance data from the substance manufacturer during the pre-registration phase to develop exposure scenarios for preparations. Default values need to be communicated in the supply chain because these were critical for the derivation of applicable risk management demands. The current guidelines which rely on the available toxicological knowledge are insufficient to advise downstream users on how to develop exposure scenarios for preparations.

  5. Modern sample preparation techniques for gas chromatography-mass spectrometry analysis of environmental markers of chemical warfare agents use

    NARCIS (Netherlands)

    Terzic, O.; de Voogt, P.; Banoub, J.

    2014-01-01

    The chapter introduces problematics of on-site chemical analysis in the investigations of past chemical warfare agents (CWA) events. An overview of primary environmental degradation pathways of CWA leading to formation of chemical markers of their use is given. Conventional and modern sample

  6. Ferroelectrics onto silicon prepared by chemical solution deposition methods: from the thin film to the self-assembled systems

    Directory of Open Access Journals (Sweden)

    Calzada, M. L.

    2006-06-01

    Full Text Available The work of the authors during the last years on ferroelectric thin and ultra-thin films deposited by Chemical Solution Deposition (CSD onto silicon based substrates is reviewed in this paper. Ferroelectric layers integrated with silicon substrates have potential use in the new micro/nanoelectronic devices. Two hot issues are here considered: 1 the use of low processing temperatures of the ferroelectric film, with the objective of not producing any damage on the different elements of the device heterostructure, and 2 the downscaling of the ferroelectric material with the aim of achieving the high densities of integration required in the next generation of nanoelectronic devices. The UV-assisted Rapid Thermal Processing has successfully been used in our laboratory for the fabrication of ferroelectric films at low temperatures. Preliminary results on the CSD preparation of nanosized ferroelectric structures are shown.

    Este artículo revisa el trabajo realizado por los autores durante los últimos años sobre lámina delgada y ultra-delgada ferroeléctrica preparada mediante el depósito químico de disoluciones (CSD sobre substratos de silicio. Las películas ferroeléctricas integradas con silicio tienen potenciales usos en los nuevos dispositivos micro/nanoelectrónicos. Dos aspectos claves son aquí considerados: 1 el uso de bajas temperaturas de procesado de la lámina ferroeléctrica, con el fin de no dañar los diferentes elementos que forman la heteroestructura del dispositivo y 2 la disminución de tamaño del material ferroeléctrico con el fin de conseguir las altas densidades de integración requeridas en la próxima generación de dispositivos nanoelectróncos. Los procesos térmicos rápidos asistidos con irradiación UV se están usando en nuestro laboratorio para conseguir la fabricación del material ferroeléctrico a temperaturas bajas compatibles con la tecnología del silicio. Se muestran resultados preliminares sobre

  7. Restart of the chemical preparation process for the fabrication of ZnO varistors for ferroelectric neutron generator power supplies

    International Nuclear Information System (INIS)

    Lockwood, Steven John

    2005-01-01

    To date, all varistors used in ferroelectric neutron generators have been supplied from a single, proprietary source, General Electric Corporate Research and Development (GE CR and D). To protect against the vulnerability of a single source, Sandia initiated a program in the early 1980's to develop a second source for this material. A chemical preparation process for making homogeneous, high purity ZnO-based varistor powder was generated, scaled to production quantities, and transferred to external suppliers. In 1992, the chem-prep varistor program was suspended when it appeared there was sufficient inventory of GE CR and D material to supply ferroelectric neutron generator production for many years. In 1999, neutron generator production schedules increased substantially, resulting in a predicted exhaustion of the existing supply of varistor material within five years. The chem-prep program was restarted in January, 2000. The goals of the program were to (1) duplicate the chem-prep powder synthesis process that had been qualified for WR production, (2) demonstrate sintered billets from the chem-prep powder met requirements, (3) develop a process for rod fabrication and demonstrate that all component specifications could be met, and (4) optimize the process from powder synthesis through component fabrication for full-scale production. The first three of these goals have been met and are discussed in this report. A facility for the fabrication of production quantities of chem-prep powder has been established. All batches since the restart have met compositional requirements, but differences in sintering behavior between the original process and the restarted process were noted. Investigation into the equipment, precipitant stoichiometry, and powder processing procedures were not able to resolve the discrepancies. It was determined that the restarted process, which incorporated Na doping for electrical stability (a process that was not introduced until the end of the

  8. Preparation of Polymeric Resin Beads Using Gamma Irradiation and Chemical Processes for Use in the Recovery of Some Alkali Metal Ions

    International Nuclear Information System (INIS)

    El-Nahas, H. H.; Khalil, F. H.; Ibrahim, G. M.; El-Gammal, B.

    2007-01-01

    Syntheses of resin beads from unsaturated polyester and urea-formaldehyde were carried out by dispersion polymerization. The reaction was performed through gamma irradiation and chemical processing. Factors affecting the reaction and syntheses parameters that are the type and viscosity of dispersant, irradiation dose and agitation rate on the resin beads size were thoroughly investigated. The resulting resin beads were smooth on their spherical surface and the beads diameters were in the range 2-200μm. Some measurements such as beads diameter, surface hardness and scanning electron microscopy were studied. The bead diameter was generally decreased with increasing concentration and viscosity of the dispersant and agitation rate. A comparison study between irradiation and chemical processes for resin beads synthesis was discussed to identify the suitable process for preparing a resin beads in a pilot scale. The different methods of preparation were tried to be applied in the recovery of Li + , Na+, k + and Cs + ions from acidic media.

  9. Possible preparation of wood-plastic materials based on unsaturated polyester resins and methyl metacrylate, by radiation and chemical methods in combination

    International Nuclear Information System (INIS)

    Pesek, M.

    1982-01-01

    The preparation of wood-plastic combinations (WPC) using combined methods for curing intermediate products and final products is described. In the first step, impregnated wood was irradiated using doses of 1 to 10 kGy in the presence of chemical initiators of polymerization. Thereafter, curing of this partly cured impregnating mixture was accomplished in the wood at elevated temperatures with the aid of chemical initiators of polymerization. Impregnation mixtures based on unsaturated polyester resins and methyl methacrylate, and the wood species European Beech (Fagus silvatica) and Black Alder (Alnus glutinosa) were used. The results indicate that this method of preparing WPC allows substantially lower radiation doses to be used, i.e., doses in the range of 1 to 2.5 kGy. These doses gelatinate the impregnation mixture in the wood so that the subsequent curing by chemical polymerization initiators proceeds without the impregnation mixture flowing out of the wood, and without forming bosses and incrustations. Intermediate products and wood products needing no further finish may thus be prepared: in some cases regrinding or repolish is sufficient. The possibility of using impregnation mixtures based on various unsaturated polyester resins was investigated, and the influence on the curing process of temperature, polymerization initiator concentration, methyl methacrylate concentration, inhibitor concentration, and other factors affecting curing was evaluated. (author)

  10. Combining Chemical Information Literacy, Communication Skills, Career Preparation, Ethics, and Peer Review in a Team-Taught Chemistry Course

    Science.gov (United States)

    Jones, Mary Lou Baker; Seybold, Paul G.

    2016-01-01

    The widely acknowledged need to include chemical information competencies and communication skills in the undergraduate chemistry curriculum can be accommodated in a variety of ways. We describe a team-taught, semester-length course at Wright State University which combines chemical information literacy, written and oral communication skills,…

  11. Sol-gel process preparation and evaluation of the analytical performances of an hydrazine specific chemical sensor

    International Nuclear Information System (INIS)

    Gojon, C.

    1996-12-01

    The realisation of optical fibers active chemical collector to analyze hydrazine in line, in the spent fuel reprocessing process is the subject of this work. The p.dimethyl-amino-benzaldehyde has been chosen as reagent for its chemical and optical properties

  12. Chemical stability of insulin. 2. Formation of higher molecular weight transformation products during storage of pharmaceutical preparations.

    Science.gov (United States)

    Brange, J; Havelund, S; Hougaard, P

    1992-06-01

    Formation of covalent, higher molecular weight transformation (HMWT) products during storage of insulin preparations at 4-45 degrees C was studied by size exclusion chromatography. The main products are covalent insulin dimers (CID), but in protamine-containing preparations the concurrent formation of covalent insulin-protamine (CIP) products takes place. At temperatures greater than or equal to 25 degrees C parallel or consecutive formation of covalent oligo- and polymers can also be observed. Rate of HMWT is only slightly influenced by species of insulin but varies with composition and formulation, and for isophane (NPH) preparations, also with the strength of preparation. Temperature has a pronounced effect on CID, CIP, and, especially, covalent oligo- and polymer formation. The CIDs are apparently formed between molecules within the hexameric unit common for all types of preparations and rate of formation is generally faster in glycerol-containing preparations. Compared with insulin hydrolysis reactions (see the preceding paper), HMWT is one order of magnitude slower, except for NPH preparations.

  13. Three-dimensional assemblies of graphene prepared by a novel chemical reduction-induced self-assembly method

    KAUST Repository

    Zhang, Lianbin

    2012-01-01

    In this study, three-dimensional (3D) graphene assemblies are prepared from graphene oxide (GO) by a facile in situ reduction-assembly method, using a novel, low-cost, and environment-friendly reducing medium which is a combination of oxalic acid (OA) and sodium iodide (NaI). It is demonstrated that the combination of a reducing acid, OA, and NaI is indispensable for effective reduction of GO in the current study and this unique combination (1) allows for tunable control over the volume of the thus-prepared graphene assemblies and (2) enables 3D graphene assemblies to be prepared from the GO suspension with a wide range of concentrations (0.1 to 4.5 mg mL-1). To the best of our knowledge, the GO concentration of 0.1 mg mL-1 is the lowest GO concentration ever reported for preparation of 3D graphene assemblies. The thus-prepared 3D graphene assemblies exhibit low density, highly porous structures, and electrically conducting properties. As a proof of concept, we show that by infiltrating a responsive polymer of polydimethylsiloxane (PDMS) into the as-resulted 3D conducting network of graphene, a conducting composite is obtained, which can be used as a sensing device for differentiating organic solvents with different polarity. © 2012 The Royal Society of Chemistry.

  14. Preparation and characterization of high surface area activated carbon from Fox nut (Euryale ferox shell by chemical activation with H3PO4

    Directory of Open Access Journals (Sweden)

    Arvind Kumar

    Full Text Available Activated carbons were prepared from Fox nutshell by chemical activation with H3PO4 in N2 atmosphere and their characteristics were studied. The effects of activation temperature and impregnation ratio were examined. N2 adsorption isotherms characterized the surface area, total pore volume, micropore volume and pore size distribution of activated carbons. Activated carbon was produced at 700 °C with a 1.5 impregnation ratio and one hour of activation time has found 2636 m2/g and 1.53 cm3/g of highest BET surface area and total pore volume, respectively. The result of Fourier-infrared spectroscopy analysis of the prepared activated carbon confirmed that the carbon has abundant functional groups on the surface. Field emission scanning electron micrographs of the prepared activated carbon showed that a porous structure formed during activation. Keywords: Activated carbons, Fox nutshell, Chemical activation, H3PO4, Activated carbon, Surface chemistry, Porous structure

  15. Preparation of carbon dioxide adsorbents from the chemical activation of urea-formaldehyde and melamine-formaldehyde resins

    Energy Technology Data Exchange (ETDEWEB)

    T.C. Drage; A. Arenillas; K.M. Smith; C. Pevida; S. Piippo; C.E. Snape [University of Nottingham, Nottingham (United Kingdom). Nottingham Fuel and Energy Centre, School of Chemical, Environmental and Mining Engineering

    2007-01-15

    Adsorption is considered to be one of the more promising technologies for the capture of CO{sub 2} from flue gases. In general, nitrogen enrichment is reported to be effective in enhancing the specific adsorbent-adsorbate interaction for CO{sub 2}. Nitrogen enriched carbons were produced from urea-formaldehyde and melamine-formaldehyde resins polymerised in the presence of K{sub 2}CO{sub 3} as a chemical activation agent, with activation undertaken over a range of temperatures. CO{sub 2} adsorption capacity was determined to be dependent upon both textural properties and more importantly nitrogen functionality. Adsorbents capable of capturing above 8 wt.% CO{sub 2} at 25{sup o}C were produced from the chemical activation of urea-formaldehyde resin at 500{sup o}C. Chemical activation seems to produce more effective adsorbents than CO{sub 2} activation. 29 refs., 4 figs., 3 tabs.

  16. Storage stability of margarines produced from enzymatically interesterified fats compared to those prepared by conventional methods - Chemical properties

    DEFF Research Database (Denmark)

    Zhang, Hong; Jacobsen, Charlotte; Pedersen, Lars Saaby

    2006-01-01

    margarines in a pilot plant. Storage stability studies were carried out at storage temperatures of 5 and 25øC for 12wk. Margarines from the enzymatically interesterified fats were compared to the margarines produced by the conventional methods (chemical interesterification and physical blending......In this study, four margarine hardstocks were produced, two from enzymatically interesterified fats at 80 and 100% conversion, one from chemically randomized fat and one from physically mixed fat. These four hardstocks, blended with 50% sunflower oil, were mainly used for the production of table...... interesterified fat had higher PV in weeks4, 8 and10 than the margarines produced from the enzymatically interesterified fats and the physically blended fat. These differences were not caused by different contents of tocopherols in the hardstocks. The differences between the processes for chemical and enzymatic...

  17. Three-dimensional assemblies of graphene prepared by a novel chemical reduction-induced self-assembly method

    KAUST Repository

    Zhang, Lianbin; Chen, Guoying; Hedhili, Mohamed N.; Zhang, Hongnan; Wang, Peng

    2012-01-01

    In this study, three-dimensional (3D) graphene assemblies are prepared from graphene oxide (GO) by a facile in situ reduction-assembly method, using a novel, low-cost, and environment-friendly reducing medium which is a combination of oxalic acid

  18. STORAGE OF CHEMICALLY PRETREATED WHEAT STRAW – A MEANS TO ENSURE QUALITY RAW MATERIAL FOR PULP PREPARATION

    Directory of Open Access Journals (Sweden)

    Terttu Heikkilä

    2010-07-01

    Full Text Available The aim of this study was to evaluate effects of chemical pretreatment and storage on non-wood pulping and on pulp quality. The processes studied were hot water treatment followed by alkaline peroxide bleaching or soda cooking. The results showed that it is possible to store wheat straw outside for at least one year without significant changes in the raw material chemical composition and without adverse effects on the resulting pulp quality. The results are significant to the industry using non-woods to ensure the availability and the quality of the raw-material throughout the year in spite of the short harvesting time.

  19. Synthesis and characterization of CoPt nanoparticles prepared by room temperature chemical reduction with PAMAM dendrimer as template.

    Science.gov (United States)

    Wan, Haiying; Shi, Shifan; Bai, Litao; Shamsuzzoha, Mohammad; Harrell, J W; Street, Shane C

    2010-08-01

    We describe an approach to synthesize monodisperse CoPt nanoparticles with dendrimer as template by a simple chemical reduction method in aqueous solution using NaBH4 as reducing agent at room temperature. The as-made CoPt nanoparticles buried in the dendrimer matrix have the chemically disordered fcc structure and can be transformed to the fct phase after annealing at 700 degrees C. This is the first report of dendrimer-mediated room temperature synthesis of monodisperse magnetic nanoparticles in aqueous solution.

  20. High-throughput analysis for preparation, processing and analysis of TiO2 coatings on steel by chemical solution deposition

    International Nuclear Information System (INIS)

    Cuadrado Gil, Marcos; Van Driessche, Isabel; Van Gils, Sake; Lommens, Petra; Castelein, Pieter; De Buysser, Klaartje

    2012-01-01

    Highlights: ► High-throughput preparation of TiO 2 aqueous precursors. ► Analysis of stability and surface tension. ► Deposition of TiO 2 coatings. - Abstract: A high-throughput preparation, processing and analysis of titania coatings prepared by chemical solution deposition from water-based precursors at low temperature (≈250 °C) on two different types of steel substrates (Aluzinc® and bright annealed) is presented. The use of the high-throughput equipment allows fast preparation of multiple samples saving time, energy and material; and helps to test the scalability of the process. The process itself includes the use of IR curing for aqueous ceramic precursors and possibilities of using UV irradiation before the final sintering step. The IR curing method permits a much faster curing step compared to normal high temperature treatments in traditional convection devices (i.e., tube furnaces). The formulations, also prepared by high-throughput equipment, are found to be stable in the operational pH range of the substrates (6.5–8.5). Titanium alkoxides itself lack stability in pure water-based environments, but the presence of the different organic complexing agents prevents it from hydrolysis and precipitation reactions. The wetting interaction between the substrates and the various formulations is studied by the determination of the surface free energy of the substrates and the polar and dispersive components of the surface tension of the solutions. The mild temperature program used for preparation of the coatings however does not lead to the formation of pure crystalline material, necessary for the desired photocatalytic and super-hydrophilic behavior of these coatings. Nevertheless, some activity can be reported for these amorphous coatings by monitoring the discoloration of methylene blue in water under UV irradiation.

  1. 13-year overview of serious adverse drug reactions following subcutaneous specific immunotherapy with a chemically modified allergen preparation.

    Science.gov (United States)

    Distler, Andreas; Pappelendam, Debbie

    The Paul-Ehrlich-Institut (PEI) published an analysis of reports of adverse drug reactions (ADRs) in 2001 with test and therapy allergens from the period from 1991 to 2000. Possible risk factors were evaluated for the ADR reports classified as "serious". During the analyzed period, modified semi-depot preparations (allergoids) induced between 0.01 % and 0.0005 % serious systemic reactions, i. e. one serious ADR occurred in 10,000 to 200,000 injections. No information was provided regarding the respective incidences in relation to the individual companies or preparations. Within the scope of a 13-year analysis (2001-2013), the serious ADRs were analysed at HAL for the allergoid preparations PURETHAL® Pollen and Mites. As in the analysis of PEI, the frequency of serious ADRs was based on the estimated number of administered injections. A total of 46 cases with serious ADRs were received. In 26 % of the cases, a serious ADR occurred during initial treatment after the first injection. In 82.6 % of the cases, the serious ADR occurred within the 30-minute observation period in the practice. Adrenaline was administered as emergency treatment in seven cases. Hospitalisations were initiated by the treating physician or by patients themselves in 45 cases. The duration of the hospital stay varied from a few hours up to three days for further monitoring. Serious ADRs occurred in 11 cases with mites and in 35 cases with pollen. If it is assumed that there are six injections in each vial, this yields an incidence of 0.00061 % (1 : 164,000). The frequency with mites (0.00093 %) was slightly higher than with pollen (0.00055 %). The allergoid preparations (pollen and mite allergens) showed a very low risk of serious ADRs, which was close to the lower level of incidence of 0.0005 % for allergoid preparations published by the PEI.

  2. Physico-chemical effects of supercritical carbon dioxide post polymerization treatment on HCl-doped polyaniline prepared via oxidative chemical polymerization

    Science.gov (United States)

    Fernando, J. G.; Vequizo, R. M.; Odarve, M. K. G.; Sambo, B. R. B.; Alguno, A. C.; Malaluan, R. M.; Candidato, R. T., Jr.; Gambe, J. E.; Jabian, M.; Paylaga, G. J.; Bagsican, F. R. G.; Miyata, H.

    2015-06-01

    Polyanilinefilms doped with varying HClconcentrations (0.2 M, 0.6 M and 1.0 M) were synthesized on glass substrates via oxidative polymerization of aniline. The films were treated with supercritical carbon dioxide (SC-CO2) at 30 MPa and 40°C for 30 minutes. Their structural, optical and morphological properties were studied and compared to conventionally prepared polyanilinefilms using FTIR analysis, UVVisspectroscopy and scanning electron microscopy. It was observed that supercritical carbon dioxide (SC-CO2) could interact with PANI films that consequently altered the bandgapsand changed the film thickness. SC-CO2 treatment also increased the oxidation level of polyanilinefilms and modified the morphology of polyanilinefilm doped with 1M HCl.

  3. Thick Fe2O3, Fe3O4 films prepared by the chemical solution deposition method

    Czech Academy of Sciences Publication Activity Database

    Buršík, Josef; Košovan, P.; Šubrt, Jan

    2006-01-01

    Roč. 39, č. 2 (2006), s. 85-94 ISSN 0928-0707 R&D Projects: GA ČR GA203/01/0408 Institutional research plan: CEZ:AV0Z40320502 Keywords : chemical solution deposition * thick films * alpha-Fe2O3 Subject RIV: CA - Inorganic Chemistry Impact factor: 1.009, year: 2006

  4. Infrared and Raman spectroscopy study of AsS chalcogenide films prepared by plasma-enhanced chemical vapor deposition.

    Science.gov (United States)

    Mochalov, Leonid; Dorosz, Dominik; Kudryashov, Mikhail; Nezhdanov, Aleksey; Usanov, Dmitry; Gogova, Daniela; Zelentsov, Sergey; Boryakov, Aleksey; Mashin, Alexandr

    2018-03-15

    AsS chalcogenide films, where As content is 60-40at.%, have been prepared via a RF non-equilibrium low-temperature argon plasma discharge, using volatile As and S as the precursors. Optical properties of the films were studied in UV-visible-NIR region in the range from 0.2 to 2.5μm. Infrared and Raman spectroscopy have been employed for the elucidation of the molecular structure of the newly developed material. It was established that PECVD films possess a higher degree of transparency (up to 80%) and a wider transparency window (>20μm) in comparison with the "usual" AsS thin films, prepared by different thermal methods, which is highly advantageous for certain applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Preparation and characterization of SnO2 thin film by chemical bath deposition method for solar cell application

    International Nuclear Information System (INIS)

    Wan Mohd Zin Wan Yunus; Saeideh Ebrahimiasl; Anuar Kassim

    2009-01-01

    Full text: Tin oxide thin films were synthesized by chemical bath deposition method on glass substrate .The as-deposited thin films were characterized for compositional, structural, surface morphological, optical and electrical properties. The X-ray diffraction patterns of the sample indicate that all samples are polycrystalline structure. AFM images show that the films consist of small uniform grains and are free of pinholes. (author)

  6. Structural and XPS studies of PSi/TiO2 nanocomposites prepared by ALD and Ag-assisted chemical etching

    International Nuclear Information System (INIS)

    Iatsunskyi, Igor; Kempiński, Mateusz; Nowaczyk, Grzegorz; Jancelewicz, Mariusz; Pavlenko, Mykola; Załęski, Karol; Jurga, Stefan

    2015-01-01

    Highlights: • Porous silicon/TiO 2 nanocomposites have been investigated. • Morphology and chemical composition of PSi/TiO 2 nanocomposites were established. • Valence-band XPS maximums for PSi/TiO 2 nanocomposites were found and analyzed. - Abstract: PSi/TiO 2 nanocomposites fabricated by atomic layer deposition (ALD) and metal-assisted chemical etching (MACE) were investigated. The morphology and phase structure of PSi/TiO 2 nanocomposites were studied by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM) with an energy dispersive X-ray spectroscopy (EDX) and Raman spectroscopy. The mean size of TiO 2 nanocrystals was determined by TEM and Raman spectroscopy. X-ray photoelectron spectroscopy (XPS) was used to analyze the chemical elemental composition by observing the behavior of the Ti 2p, O 1s and Si 2p lines. TEM, Raman spectroscopy and XPS binding energy analysis confirmed the formation of TiO 2 anatase phase inside the PSi matrix. The XPS valence band analysis was performed in order to investigate the modification of PSi/TiO 2 nanocomposites electronic structure. Surface defects states of Ti 3+ at PSi/TiO 2 nanocomposites were identified by analyzing of XPS valence band spectra

  7. Preparation and Characterization of Conducting Polymer Latices by Chemical Polymerization of Aniline or Anisidine in Presence of Latex: Study of Their Electroactivity and Anti-Corrosion Properties

    Directory of Open Access Journals (Sweden)

    Bakhshali Massoumi

    2013-06-01

    Full Text Available Poly (vinylacetate-co-butylmethacrylate was prepared in presence of potassium persulphate as an oxidizing agent in aqueous solution of dodecylbenzene sulfonate sodium as an emulsifying agent. Then, aniline was polymerized by chemical oxidation method at three different concentrations of aniline monomer (0.1, 0.2 and 0.3 M in toluene in presence of poly(vinylacetate-co-butylmethacrylate in order to obtain polyaniline/poly(vinylacetate-co-butylmethacrylate. To prepare conducting-latex of polyanisidine/poly(vinylacetate-co-butylmethacrylate the same method was employed as above for aniline monomer in obtaining conducting polyaniline/poly(vinylacetate-co-butylmethacrylate latex. In addition, the purification of conducting-latex polymers, polyaniline/poly(vinylacetate-co-butylmethacrylate and polyanisidine/poly(vinylacetate-co-butylmethacrylate was conducted and preparation of tin layer films of conducting-latex polymers was carried out by casting method on glassy lames. The electroactivity properties of the prepared latex-polymers, polyaniline/poly(vinylacetate-co-butylmethacrylate and polyanisidine/poly(vinylacetate-co-butylmethacrylate were investigated by cyclic voltammetery (CV. The voltamogrames showed that the latex films were electroactive. Because of conductivity and electroactivity, the obtained films may find applications in anti-corrosion coatings. The anti-corrosion properties of conducting-latex polymers were studied on aluminum surface by impedance technique. The structure of the prepared conducting-latex polymers was confirmed by Fourier transform infrared (FTIR. Finally, the electrical conductivity of synthesized conducting-latex polymers, polyaniline/poly(vinylacetate-co-butylmethacrylate and polyanisidine/poly(vinylacetate-co-butylmethacrylate was measured by four probe technique.

  8. Investigation of deposition characteristics and properties of high-rate deposited silicon nitride films prepared by atmospheric pressure plasma chemical vapor deposition

    International Nuclear Information System (INIS)

    Kakiuchi, H.; Nakahama, Y.; Ohmi, H.; Yasutake, K.; Yoshii, K.; Mori, Y.

    2005-01-01

    Silicon nitride (SiN x ) films have been prepared at extremely high deposition rates by the atmospheric pressure plasma chemical vapor deposition (AP-PCVD) technique on Si(001) wafers from gas mixtures containing He, H 2 , SiH 4 and N 2 or NH 3 . A 150 MHz very high frequency (VHF) power supply was used to generate high-density radicals in the atmospheric pressure plasma. Deposition rate, composition and morphology of the SiN x films prepared with various deposition parameters were studied by scanning electron microscopy and Auger electron spectroscopy. Fourier transformation infrared (FTIR) absorption spectroscopy was also used to characterize the structure and the chemical bonding configurations of the films. Furthermore, etching rate with buffered hydrofluoric acid (BHF) solution, refractive index and capacitance-voltage (C-V) characteristics were measured to evaluate the dielectric properties of the films. It was found that effective passivation of dangling bonds and elimination of excessive hydrogen atoms at the film-growing surface seemed to be the most important factor to form SiN x film with a dense Si-N network. The C-V curve of the optimized film showed good interface properties, although further improvement was necessary for use in the industrial metal-insulator-semiconductor (MIS) applications

  9. Analyte-triggered luminescence of Eu{sup 3+} ions encapsulated in Nafion membranes -preparation of hybrid materials from in membrane chemical reactions-

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar-Sánchez, Rocío, E-mail: raguilar@ifuap.buap.mx [Depto. Química Analítica, Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Puebla 72570 (Mexico); Zelocualtecatl-Montiel, Iván [Depto. Química Analítica, Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Puebla 72570 (Mexico); Gálvez-Vázquez, María de Jesús [Depto. Química Analítica, Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Puebla 72570 (Mexico); Instituto de Física, Benemérita Universidad Autónoma de Puebla, Apartado postal J-48, Puebla 72570 (Mexico); Silva-González, Rutilo [Instituto de Física, Benemérita Universidad Autónoma de Puebla, Apartado postal J-48, Puebla 72570 (Mexico)

    2017-04-15

    The possibility to perform chemical reactions inside polymer materials opens a unique opportunity to control and prepare materials for diverse solid-state applications. Based on the affinity of Eu{sup 3+} ions for oxygen functionalities, in this work we report the luminescence enhancement of Eu{sup 3+} ions inserted in Nafion membranes (Naf/Eu{sup 3+}) by in-situ complexing to oxalate. The formation of a europium-oxalate type complex enhances Eu{sup 3+} luminescence emission, which could be exploited for the construction of devices for oxalate sensing and the fabrication of highly luminescent materials. Possible analytical applications of Naf/Eu{sup 3+} membranes were evaluated by fluorescence spectroscopy through the linear response with concentration. The complex formation was followed by infrared spectroscopy and SEM-EDS analysis. - Highlights: • Luminescence enhancement by complexation of Eu{sup 3+} ions to oxalate inside Nafion. • Performance of chemical reactions inside Nafion/polymer membranes. • An easy and novel method to prepare luminescent solid devices. • Possibility to develop luminescent sensors by analyte-triggered optical response.

  10. Chemically Methylated and Reduced Pectins: Preparation and Characterisation by 1H-NMR Spectroscopy, Enzymatic Degradation and Gelling Properties

    DEFF Research Database (Denmark)

    Rosenbohm, Christoph; Lundt, Inge; Christensen, T.M.I.E.

    2003-01-01

    with lower DM. A simple method for determination of DM by 1H-NMR spectroscopy is presented. New modified pectins have been prepared by treatment of pectins having different DM’s with NaBH4 to reduce selectively the methyl esters to primary alcohols in the presence of free acids. The degree of reduction (DR......) and the DM of the remaining carboxylic acids could likewise be determined by 1H-NMR spectroscopy. The new reduced pectins can be tolerated by the pectin degrading enzymes polygalacturonase PGI and PGII as well as by pectin lyase, all from Aspergillus niger, but the enzymes exhibit lower specific activities...

  11. Physical-chemical and technological aspects of the preparation of think layers of the high temperature superconductors Bi-Sr-Ca-Cu-O by method of metal organic vapour phase epitaxy

    International Nuclear Information System (INIS)

    Stejskal, J.; Nevriva, M.; Leitner, J.

    1995-01-01

    The method of metal organic vapour phase epitaxy (MO VPE) was used for preparation of think layers of the high temperature superconductors Bi-Sr-Ca-Cu-O. The suitable chemical precursors (β-diketonates) on the literature data and of the own thermodynamic calculations were selected. The optimal thermodynamic data and thermodynamic stability of the prepared samples were determined

  12. The effect of water on the electrochromic properties of WO{sub 3} films prepared by vacuum and chemical methods

    Energy Technology Data Exchange (ETDEWEB)

    Leftheriotis, G.; Papaefthimiou, S.; Yianoulis, P. [Department of Physics, University of Patras, Patras 26500 (Greece)

    2004-06-01

    We present a comparative study on the effect of absorbed water on the properties of tungsten oxide films prepared by two different methods (e-gun evaporation, and an aqueous sol-gel technique). Scanning electron microscopy, Fourier transform infrared spectroscopy and electrochemical techniques have been used to assess the film properties. It has been found that the preparation method of the films greatly affects their water content and thus, electron gun evaporated films have less water incorporated into their structure than their sol-gel counterparts. The former are closely packed and transparent with most of their water content adsorbed on their surface, while the latter have a porous structure, being opaque, highly hydroxylated and hydrated to a lesser extent. Both types of films exhibit reversible electrochromism, with the evaporated films being stable up to 5000 coloration-bleaching cycles and the sol-gel ones gradually degrading after 1000 cycles. Irreversible Li{sup +} trapping related to the presence of water and hydroxyl radicals has been envisaged as the cause of the inferior cycling stability of the sol-gel films.

  13. Enhancement of the electrooxidation of ethanol on Pt-Sn-P/C catalysts prepared by chemical deposition process

    Science.gov (United States)

    Xue, Xinzhong; Ge, Junjie; Tian, Tian; Liu, Changpeng; Xing, Wei; Lu, Tianhong

    In this paper, five Pt 3Sn 1/C catalysts have been prepared using three different methods. It was found that phosphorus deposited on the surface of carbon with Pt and Sn when sodium hypophosphite was used as reducing agent by optimization of synthetic conditions such as pH in the synthetic solution and temperature. The deposition of phosphorus should be effective on the size reduction and markedly reduces PtSn nanoparticle size, and raise electrochemical active surface (EAS) area of catalyst and improve the catalytic performance. TEM images show PtSnP nanoparticles are highly dispersed on the carbon surface with average diameters of 2 nm. The optimum composition is Pt 3Sn 1P 2/C (note PtSn/C-3) catalyst in my work. With this composition, it shows very high activity for the electrooxidation of ethanol and exhibit enhanced performance compared with other two Pt 3Sn 1/C catalysts that prepared using ethylene glycol reduction method (note PtSn/C-EG) and borohydride reduction method (note PtSn/-B). The maximum power densities of direct ethanol fuel cell (DEFC) were 61 mW cm -2 that is 150 and 170% higher than that of the PtSn/C-EG and PtSn/C-B catalyst.

  14. Enhancement of the electrooxidation of ethanol on Pt-Sn-P/C catalysts prepared by chemical deposition process

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Xinzhong; Ge, Junjie; Tian, Tian [Changchun Institute of Applied Chemistry, Chinese Academy of Science, Changchun 130022 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100049 (China); Liu, Changpeng; Xing, Wei; Lu, Tianhong [Changchun Institute of Applied Chemistry, Chinese Academy of Science, Changchun 130022 (China)

    2007-10-25

    In this paper, five Pt{sub 3}Sn{sub 1}/C catalysts have been prepared using three different methods. It was found that phosphorus deposited on the surface of carbon with Pt and Sn when sodium hypophosphite was used as reducing agent by optimization of synthetic conditions such as pH in the synthetic solution and temperature. The deposition of phosphorus should be effective on the size reduction and markedly reduces PtSn nanoparticle size, and raise electrochemical active surface (EAS) area of catalyst and improve the catalytic performance. TEM images show PtSnP nanoparticles are highly dispersed on the carbon surface with average diameters of 2 nm. The optimum composition is Pt{sub 3}Sn{sub 1}P{sub 2}/C (note PtSn/C-3) catalyst in my work. With this composition, it shows very high activity for the electrooxidation of ethanol and exhibit enhanced performance compared with other two Pt{sub 3}Sn{sub 1}/C catalysts that prepared using ethylene glycol reduction method (note PtSn/C-EG) and borohydride reduction method (note PtSn/-B). The maximum power densities of direct ethanol fuel cell (DEFC) were 61 mW cm{sup -2} that is 150 and 170% higher than that of the PtSn/C-EG and PtSn/C-B catalyst. (author)

  15. LiF enhanced nucleation of the low temperature microcrystalline silicon prepared by plasma enhanced chemical vapour deposition

    Czech Academy of Sciences Publication Activity Database

    Stuchlík, Jiří; Ledinský, Martin; Honda, Shinya; Drbohlav, Ivo; Mates, Tomáš; Fejfar, Antonín; Hruška, Karel; Stuchlíková, The-Ha; Kočka, Jan

    2009-01-01

    Roč. 517, č. 24 (2009), s. 6829-6832 ISSN 0040-6090 R&D Projects: GA AV ČR KAN400100701; GA ČR(CZ) GD202/05/H003; GA MŠk LC510; GA AV ČR IAA1010413 Institutional research plan: CEZ:AV0Z10100521 Keywords : amorphous hydrogenated silicon * atomic force microscopy * plasma-enhanced chemical vapour deposition, * nucleation * Raman scattering * lithium fluoride Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.727, year: 2009

  16. Microporous Ni@NiO nanoparticles prepared by chemically dealloying Al_3Ni_2@Al nanoparticles as a high microwave absorption material

    International Nuclear Information System (INIS)

    Pang, Yu; Xie, Xiubo; Li, Da; Chou, Wusheng; Liu, Tong

    2017-01-01

    The Al_3Ni_2@Al nanoparticles (NPs) were prepared from Ni_4_5Al_5_5 master alloy by hydrogen plasma-metal reaction method, and were subsequently dealloyed to produce porous Ni@NiO NPs of 36 nm. The pore size ranges from 0.7 to 1.6 nm, leading to large specific surface area of 69.5 m"2/g and big pore volume of 0.507 cc/g. The saturation magnetization (M_S) and coercivity (H_C) of the microporous Ni@NiO NPs are 11.5 emu/g and 5.2 Oe. They exhibit high microwave absorption performance with a minimum reflection coefficient (RC) of −86.9 dB and an absorption bandwidth of 2.6 GHz (RC≤−10 dB) at thickness of 4.5 mm. The enhanced microwave absorption properties are attributed to the synergistic effect of the magnetic Ni core and dielectric NiO shell, and the micropore architecture. The NPs with micropore morphology and core/shell structure open a new way to modify the microwave absorption performance. - Graphical abstract: The microporous Ni/NiO nanoparticles prepared by chemically dealloying Al_3Ni_2@Al NPs exhibit high microwave absorption intensity (−86.9 dB) and wide absorption bandwidth (2.6 GHz for RC≤−10 dB). - Highlights: • Microporous Ni/NiO nanoparticals were prepared by chemically dealloying method. • They possessed micropores of 0.7–1.6 nm with a surface area of 69.5 m"2/g. • They showed high microwave absorption intensity and wide absorption bandwidth. • Microwave absorption mechanism was explained by micropore and core/shell structures.

  17. Microporous Ni@NiO nanoparticles prepared by chemically dealloying Al{sub 3}Ni{sub 2}@Al nanoparticles as a high microwave absorption material

    Energy Technology Data Exchange (ETDEWEB)

    Pang, Yu; Xie, Xiubo; Li, Da [Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, No.37 Xueyuan Road, Beijing 100191 (China); Chou, Wusheng [School of Mechanical Engineering and Automation, Beihang University, Beijing 100191 (China); Liu, Tong, E-mail: tongliu@buaa.edu.cn [Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, No.37 Xueyuan Road, Beijing 100191 (China)

    2017-03-15

    The Al{sub 3}Ni{sub 2}@Al nanoparticles (NPs) were prepared from Ni{sub 45}Al{sub 55} master alloy by hydrogen plasma-metal reaction method, and were subsequently dealloyed to produce porous Ni@NiO NPs of 36 nm. The pore size ranges from 0.7 to 1.6 nm, leading to large specific surface area of 69.5 m{sup 2}/g and big pore volume of 0.507 cc/g. The saturation magnetization (M{sub S}) and coercivity (H{sub C}) of the microporous Ni@NiO NPs are 11.5 emu/g and 5.2 Oe. They exhibit high microwave absorption performance with a minimum reflection coefficient (RC) of −86.9 dB and an absorption bandwidth of 2.6 GHz (RC≤−10 dB) at thickness of 4.5 mm. The enhanced microwave absorption properties are attributed to the synergistic effect of the magnetic Ni core and dielectric NiO shell, and the micropore architecture. The NPs with micropore morphology and core/shell structure open a new way to modify the microwave absorption performance. - Graphical abstract: The microporous Ni/NiO nanoparticles prepared by chemically dealloying Al{sub 3}Ni{sub 2}@Al NPs exhibit high microwave absorption intensity (−86.9 dB) and wide absorption bandwidth (2.6 GHz for RC≤−10 dB). - Highlights: • Microporous Ni/NiO nanoparticals were prepared by chemically dealloying method. • They possessed micropores of 0.7–1.6 nm with a surface area of 69.5 m{sup 2}/g. • They showed high microwave absorption intensity and wide absorption bandwidth. • Microwave absorption mechanism was explained by micropore and core/shell structures.

  18. Nanoscale Chemical Characterization of Solid-State Microbattery Stacks by Means of Auger Spectroscopy and Ion-Milling Cross Section Preparation.

    Science.gov (United States)

    Uhart, A; Ledeuil, J B; Pecquenard, B; Le Cras, F; Proust, M; Martinez, H

    2017-09-27

    The current sustained demand for "smart" and connected devices has created a need for more miniaturized power sources, hence for microbatteries. Lithium-ion or "lithium-free" all-solid-state thin-film batteries are adapted solutions to this issue. The capability to carry out spatially resolved chemical analysis is fundamental for the understanding of the operation in an all-solid-state microbattery. Classically cumbersome and not straightforward techniques as TEM/STEM/EELS and FIB preparation methods could be used to address this issue. The challenge in this work is to make the characterization of Li-based material possible by coupling ion-milling cross section preparation method and AES techniques to characterize the behavior of a LiCoO 2 positive electrode in an all solid state microbattery. The surface chemistry of LiCoO 2 has been studied before and after LiPON deposition. Modifications of the chemical environments characteristic of the positive electrode have been reported at different steps of the electrochemical process. An original qualitative and a semiquantitative analysis has been used in this work with the peak deconvolution method based on real, certified reference spectra to better understand the lithiation/delithiation process. This original coupling has demonstrated that a full study of the pristine, cycled, and post mortem positive electrode in a microbattery is also possible. The ion-milling preparation method allows access to a large area, and the resolution of Auger analysis is highly resolved in energy to separate the lithium and the cobalt signals in an accurate way.

  19. High performance GdBa{sub 2}Cu{sub 3}O{sub 7-z} film preparation by non-fluorine chemical solution deposition approach

    Energy Technology Data Exchange (ETDEWEB)

    Wang, W.T.; Pu, M.H.; Wang, W.W. [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Zhang, H. [Department of Physics, Peking University, Beijing 100871 (China); Cheng, C.H. [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China)] [Superconductivity Research Group, School of Materials Science and Engineering, University of New South Wale, Sydney, 2052 NSW (Australia); Zhao, Y., E-mail: yzhao@swjtu.edu.cn [Key Laboratory of Magnetic Levitation and Maglev Trains (Ministry of Education of China), Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China)] [Superconductivity Research Group, School of Materials Science and Engineering, University of New South Wale, Sydney, 2052 NSW (Australia)

    2011-11-15

    Biaxially textured GdBa{sub 2}Cu{sub 3}O{sub 7}-z films with Tc above 93 K have been prepared on (0 0 l) by non-fluorine CSD approach. Nanoparticles with homogeneous distribution are introduced into the GdBCO films as effective pinning centers. A high Jc (77 K, 0 T) of 2.28 MA/cm{sup 2} with slow decreasing Jc-B behavior is observed in the films. Biaxially textured GdBa{sub 2}Cu{sub 3}O{sub 7-z} (GdBCO) films with T{sub c} above 93 K have been prepared on (0 0 l) LaAlO{sub 3} substrate by self-developed non-fluorine polymer-assisted chemical solution deposition (PA-CSD) approach. The GdBCO films show smooth and crack-free morphology. Many nanoscale particles with homogeneous distribution are observed in the GdBCO films, which have not been observed yet in the YBa{sub 2}Cu{sub 3}O{sub 7-z} (YBCO) films prepared by the same processing technique. Besides a high J{sub c} (77 K, 0 T) of 2.28 MA/cm{sup 2}, the optimized GdBCO films show a better J{sub c}-B behavior and an improved high-field J{sub c}, compared to the YBCO films.

  20. Effect of gamma irradiation on microbial load, chemical and sensory properties of chicken kabab and sausage; as prepared chilled meals

    International Nuclear Information System (INIS)

    Al-Bachir, M.

    2009-05-01

    Chicken kabab and sausage were treated with 0, 2, 4 or 6 kGy doses of gamma irradiation in a 60 CO package irradiator. Treated and untreated samples were kept in a refrigerator (1-4 degree centigrade). Microbiological, chemical and sensory characteristics of chicken kabab and sausage were evaluated at 0, 1, 2, 3, 4, and 5 months of storage. Proximate composition and sensory evaluation of the chicken kabab and sausage were also investigated, but only immediately after treatment. Irradiation did not influence the major constituents of chicken kabab and sausage (moisture, protein and fats). Gamma irradiation decreased the microbial load and increased the shelf-life of chicken kabab and sausage. The dose needed to decrease by 1 log cfu/g (D 1 0 value) of Salmonella spp and E coli. numbers were 213 and 400 Gy in chicken kabab, while 345 and 250 Gy in chicken sausage, respectively. The chemical parameters, total acidity, volatile basic nitrogen (VBN), and thiobarbituric acid reactive substances (TBARS), which were chosen as the indices of freshness, were all well within the acceptable limit for up to 5 months for chicken kabab and sausage treated with 4 and 6 kGy. Sensory evaluation showed no significant differences between irradiated and non-irradiated samples. (author)

  1. Paraffin/expanded graphite phase change composites with enhanced thermal conductivity prepared by implanted β-SiC nanowires with chemical vapor deposition method

    Science.gov (United States)

    Yin, Zhaoyu; Zhang, Xiaoguang; Huang, Zhaohui; Liu, Silin; Zhang, Weiyi; Liu, Yan'gai; Wu, Xiaowen; Fang, Minghao; Min, Xin

    2018-02-01

    Expanded graphite/β-SiC nanowires composites (ESNC) were prepared through chemical vapor deposition, and paraffin/expanded graphite/β-SiC nanowires composites (PESNC) were made through vacuum impregnation to overcome liquid leakage during phase transition and enhance the thermal conductivity of paraffin. Fourier transform infrared spectroscopy showed no chemical interactions between the paraffin and ESNC. Differential scanning calorimetry estimated the temperature and latent heat of PESNC during melting to 45.73 °C and 124.31 J g-1, respectively. The respective values of these quantities during freezing were recorded as 48.93 °C and 124.14 J g-1. The thermal conductivity of PESNC was estimated to 0.75 W mK-1, which was 3.26-folds that of pure paraffin (0.23 W mK-1). PESNC perfectly maintained its phase transition after 200 melting-freezing cycles. The resulting ideal thermal conductivity, good chemical stability, thermal properties and thermal reliability of PESNC are promising for use in energy efficient buildings and solar energy systems.

  2. Study of the crystallographic phase change on copper (I) selenide thin films prepared through chemical bath deposition by varying the pH of the solution

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval-Paz, M.G., E-mail: myrnasandoval@udec.cl [Departament of Physics, Faculty of Physical Sciences and Mathematics, University of Concepcion, Box 160-C, Concepción (Chile); Rodríguez, C.A. [Department of Materials Engineering, Faculty of Engineering, University of Concepción, Edmundo Larenas 270, Concepción 4070409 (Chile); Porcile-Saavedra, P.F. [Departament of Physics, Faculty of Physical Sciences and Mathematics, University of Concepcion, Box 160-C, Concepción (Chile); Trejo-Cruz, C. [Department of Physics, Faculty of Science, University of Biobío, Avenue Collao 1202, Box 5C, Concepción 4051381 (Chile)

    2016-07-15

    Copper (I) selenide thin films with orthorhombic and cubic structure were deposited on glass substrates by using the chemical bath deposition technique. The effects of the solution pH on the films growth and subsequently the structural, optical and electrical properties of the films were studied. Films with orthorhombic structure were obtained from baths wherein both metal complex and hydroxide coexist; while films with cubic structure were obtained from baths where the metal hydroxide there is no present. The structural modifications are accompanied by changes in bandgap energy, morphology and electrical resistivity of the films. - Graphical abstract: “Study of the crystallographic phase change on copper (I) selenide thin films prepared through chemical bath deposition by varying the pH of the solution” by M. G. Sandoval-Paz, C. A. Rodríguez, P. F. Porcile-Saavedra, C. Trejo-Cruz. Display Omitted - Highlights: • Copper (I) selenide thin films were obtained by chemical bath deposition. • Orthorhombic to cubic phase change was induced by varying the reaction solution pH. • Orthorhombic phase is obtained mainly from a hydroxides cluster mechanism. • Cubic phase is obtained mainly from an ion by ion mechanism. • Structural, optical and electrical properties are presented as a function of pH.

  3. From alchemy to super-actinides. The preparation, physical-chemical properties and the limits of the Periodic Table

    International Nuclear Information System (INIS)

    Kuruc, J.

    2016-01-01

    In this review a brief history of the discovery of the periodic law, discoveries of elements from the epoch of alchemy to the synthesis of actinides and transactinides is described. The preparation of transactinides (elements with Z ≥ 104 to Z = 118) is discussed, using already proposed names of the elements with Z = 113, 115, 117 and 118: nihonium, moscovium, tennessine and oganesson. The Periodic Tables are presented in short form, the long 18-column and 32-column form. The periodic table containing elements of 8"t"h and 9"t"h periods and its possible range is discussed. By extrapolation of decay half-time of the heaviest isotopes of elements from thorium up to oganesson decay half-time of unbihexium (Z = 126) was predicted about 378 seconds. (author

  4. Chemical fingerprinting and quantitative analysis of a Panax notoginseng preparation using HPLC-UV and HPLC-MS

    Directory of Open Access Journals (Sweden)

    Shao Qing

    2011-02-01

    Full Text Available Abstract Background Xuesaitong (XST injection, consisting of total saponins from Panax notoginseng, was widely used for the treatment of cardio- and cerebro-vascular diseases in China. This study develops a simple and global quality evaluation method for the quality control of XST. Methods High performance liquid chromatography-ultraviolet detection (HPLC-UV was used to identify and quantify the chromatographic fingerprints of the XST injection. Characteristic common peaks were identified using HPLC with photo diode array detection/electrospray ionization tandem mass spectrometry (HPLC-PDA/ESI-MSn. Results Representative fingerprints from ten batches of samples showed 27 'common saponins' all of which were identified and quantified using ten reference saponins. Conclusion Chemical fingerprinting and quantitative analysis identified most of the common saponins for the quality control of P. notoginseng products such as the XST injection.

  5. Structural, optical and photocatalytic properties of flower-like ZnO nanostructures prepared by a facile wet chemical method

    Directory of Open Access Journals (Sweden)

    Sini Kuriakose

    2013-11-01

    Full Text Available Flower-like ZnO nanostructures were synthesized by a facile wet chemical method. Structural, optical and photocatalytic properties of these nanostructures have been studied by X-ray diffraction (XRD, scanning electron microscopy (SEM, transmission electron microscopy (TEM, photoluminescence (PL and UV–vis absorption spectroscopy. SEM and TEM studies revealed flower-like structures consisting of nanosheets, formed due to oriented attachment of ZnO nanoparticles. Flower-like ZnO structures showed enhanced photocatalytic activity towards sun-light driven photodegradation of methylene blue dye (MB as compared to ZnO nanoparticles. XRD, UV–vis absorption, PL, FTIR and TEM studies revealed the formation of Zn(OH2 surface layer on ZnO nanostructures upon ageing. We demonstrate that the formation of a passivating Zn(OH2 surface layer on the ZnO nanostructures upon ageing deteriorates their efficiency to photocatalytically degrade of MB.

  6. Wet-Chemical Preparation of Silicon Tunnel Oxides for Transparent Passivated Contacts in Crystalline Silicon Solar Cells.

    Science.gov (United States)

    Köhler, Malte; Pomaska, Manuel; Lentz, Florian; Finger, Friedhelm; Rau, Uwe; Ding, Kaining

    2018-05-02

    Transparent passivated contacts (TPCs) using a wide band gap microcrystalline silicon carbide (μc-SiC:H(n)), silicon tunnel oxide (SiO 2 ) stack are an alternative to amorphous silicon-based contacts for the front side of silicon heterojunction solar cells. In a systematic study of the μc-SiC:H(n)/SiO 2 /c-Si contact, we investigated selected wet-chemical oxidation methods for the formation of ultrathin SiO 2 , in order to passivate the silicon surface while ensuring a low contact resistivity. By tuning the SiO 2 properties, implied open-circuit voltages of 714 mV and contact resistivities of 32 mΩ cm 2 were achieved using μc-SiC:H(n)/SiO 2 /c-Si as transparent passivated contacts.

  7. Structural and optical properties of nano-structured CdS thin films prepared by chemical bath deposition

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Rekha, E-mail: rekha.mittal07@gmail.com; Kumar, Dinesh; Chaudhary, Sujeet; Pandya, Dinesh K. [Thin Film Laboratory, Physics Department, Indian Institute of Technology Delhi, New Delhi-110016 (India)

    2016-05-06

    Cadmium sulfide (CdS) thin films have been deposited on conducting glass substrates by chemical bath deposition (CBD) technique. The effect of precursor concentration on the structural, morphological, compositional, and optical properties of the CdS films has been studied. Crystal structure of these CdS films is characterized by X-ray diffraction (XRD) and it reveals polycrystalline structure with mixture of cubic and wurtzite phases with grain size decreasing as precursor concentration is increased. Optical studies reveal that the CdS thin films have high transmittance in visible spectral region reaching 90% and the films possess direct optical band gap that decreases from 2.46 to 2.39 eV with decreasing bath concentration. Our study suggests that growth is nucleation controlled.

  8. Characteristics of Ge-Sb-Te films prepared by cyclic pulsed plasma-enhanced chemical vapor deposition.

    Science.gov (United States)

    Suk, Kyung-Suk; Jung, Ha-Na; Woo, Hee-Gweon; Park, Don-Hee; Kim, Do-Heyoung

    2010-05-01

    Ge-Sb-Te (GST) thin films were deposited on TiN, SiO2, and Si substrates by cyclic-pulsed plasma-enhanced chemical vapor deposition (PECVD) using Ge{N(CH3)(C2H5)}, Sb(C3H7)3, Te(C3H7)3 as precursors in a vertical flow reactor. Plasma activated H2 was used as the reducing agent. The growth behavior was strongly dependent on the type of substrate. GST grew as a continuous film on TiN regardless of the substrate temperature. However, GST formed only small crystalline aggregates on Si and SiO2 substrates, not a continuous film, at substrate temperatures > or = 200 degrees C. The effects of the deposition temperature on the surface morphology, roughness, resistivity, crystallinity, and composition of the GST films were examined.

  9. Structural and optical properties of nano-structured CdS thin films prepared by chemical bath deposition

    International Nuclear Information System (INIS)

    Bai, Rekha; Kumar, Dinesh; Chaudhary, Sujeet; Pandya, Dinesh K.

    2016-01-01

    Cadmium sulfide (CdS) thin films have been deposited on conducting glass substrates by chemical bath deposition (CBD) technique. The effect of precursor concentration on the structural, morphological, compositional, and optical properties of the CdS films has been studied. Crystal structure of these CdS films is characterized by X-ray diffraction (XRD) and it reveals polycrystalline structure with mixture of cubic and wurtzite phases with grain size decreasing as precursor concentration is increased. Optical studies reveal that the CdS thin films have high transmittance in visible spectral region reaching 90% and the films possess direct optical band gap that decreases from 2.46 to 2.39 eV with decreasing bath concentration. Our study suggests that growth is nucleation controlled.

  10. Raman Spectroscopic Study of Carbon Nano tubes Prepared Using Fe/ZnO-Palm Olein-Chemical Vapour Deposition Syazwan

    International Nuclear Information System (INIS)

    Zobir, A.M.; Abdullah, S.; Rusop, M.; Abdullah, S.; Abu Bakar, S.; Zainal, Z.; Sarijo, S.H.; Rusop, M.

    2012-01-01

    Multi walled carbon nano tubes (MWCNTs) were synthesized using Fe/ZnO catalyst by a dual-furnace thermal chemical vapor deposition (CVD) method at 800-1000 degree C using nitrogen gas with a constant flow rate of 150 sccm/min as a gas carrier. Palm olein (PO), ferrocene in the presence of 0.05 M zinc nitrate, and a p-type silicon wafer were used as carbon source, catalyst precursor, and sample target, respectively. D, G, and G' bands were observed at 1336-1364, 1559-1680, and 2667-2682 cm -1 , respectively. Carbon nano tubes (CNTs) with the highest degree of crystallinity were obtained at around 8000 degree C, and the smallest diameter of about 2 nm was deposited on the silicon substrate at 1000 degree C.

  11. Raman Spectroscopic Study of Carbon Nanotubes Prepared Using Fe/ZnO-Palm Olein-Chemical Vapour Deposition

    Directory of Open Access Journals (Sweden)

    Syazwan Afif Mohd Zobir

    2012-01-01

    Full Text Available Multiwalled carbon nanotubes (MWCNTs were synthesized using Fe/ZnO catalyst by a dual-furnace thermal chemical vapor deposition (CVD method at 800–1000°C using nitrogen gas with a constant flow rate of 150 sccm/min as a gas carrier. Palm olein (PO, ferrocene in the presence of 0.05 M zinc nitrate, and a p-type silicon wafer were used as carbon source, catalyst precursor, and sample target, respectively. D, G, and G′ bands were observed at 1336–1364, 1559–1680, and 2667–2682 cm-1, respectively. Carbon nanotubes (CNTs with the highest degree of crystallinity were obtained at around 8000°C, and the smallest diameter of about 2 nm was deposited on the silicon substrate at 1000°C.

  12. Characterization of thin TiO2 films prepared by plasma enhanced chemical vapour deposition for optical and photocatalytic applications

    International Nuclear Information System (INIS)

    Sobczyk-Guzenda, A.; Gazicki-Lipman, M.; Szymanowski, H.; Kowalski, J.; Wojciechowski, P.; Halamus, T.; Tracz, A.

    2009-01-01

    Thin titanium oxide films were deposited using a radio frequency (RF) plasma enhanced chemical vapour deposition method. Their optical properties and thickness were determined by means of ultraviolet-visible absorption spectrophotometry. Films of the optical parameters very close to those of titanium dioxide have been obtained at the high RF power input. Their optical quality is high enough to allow for their use in a construction of stack interference optical filters. At the same time, these materials exhibit strong photocatalytic effects. The results of structural analysis, carried out by Raman Shift Spectroscopy, show that the coatings posses amorphous structure. However, Raman spectra of the same films subjected to thermal annealing at 450 o C disclose an appearance of a crystalline form, namely that of anatase. Surface morphology of the films has also been characterized by Atomic Force Microscopy revealing granular, broccoli-like topography of the films.

  13. Nanoscale multilayered and porous carbide interphases prepared by pressure-pulsed reactive chemical vapor deposition for ceramic matrix composites

    International Nuclear Information System (INIS)

    Jacques, S.; Jouanny, I.; Ledain, O.; Maillé, L.; Weisbecker, P.

    2013-01-01

    In Ceramic Matrix Composites (CMCs) reinforced by continuous fibers, a good toughness is achieved by adding a thin film called “interphase” between the fiber and the brittle matrix, which acts as a mechanical fuse by deflecting the matrix cracks. Pyrocarbon (PyC), with or without carbide sub-layers, is typically the material of choice to fulfill this role. The aim of this work was to study PyC-free nanoscale multilayered carbide coatings as interphases for CMCs. Nanoscale multilayered (SiC–TiC) n interphases were deposited by pressure-Pulsed Chemical Vapor Deposition (P-CVD) on single filament Hi-Nicalon fibers and embedded in a SiC matrix sheath. The thicknesses of the carbide interphase sub-layers could be made as low as a few nanometers as evidenced by scanning and transmission electron microscopy. By using the P-ReactiveCVD method (P-RCVD), in which the TiC growth involves consumption of SiC, it was not only possible to obtain multilayered (SiC–TiC) n films but also TiC films with a porous multilayered microstructure as a result of the Kirkendall effect. The porosity in the TiC sequences was found to be enhanced when some PyC was added to SiC prior to total RCVD consumption. Because the porosity volume fraction was still not high enough, the role of mechanical fuse of the interphases could not be evidenced from the tensile curves, which remained fully linear even when chemical attack of the fiber surface was avoided.

  14. Nanoscale multilayered and porous carbide interphases prepared by pressure-pulsed reactive chemical vapor deposition for ceramic matrix composites

    Science.gov (United States)

    Jacques, S.; Jouanny, I.; Ledain, O.; Maillé, L.; Weisbecker, P.

    2013-06-01

    In Ceramic Matrix Composites (CMCs) reinforced by continuous fibers, a good toughness is achieved by adding a thin film called "interphase" between the fiber and the brittle matrix, which acts as a mechanical fuse by deflecting the matrix cracks. Pyrocarbon (PyC), with or without carbide sub-layers, is typically the material of choice to fulfill this role. The aim of this work was to study PyC-free nanoscale multilayered carbide coatings as interphases for CMCs. Nanoscale multilayered (SiC-TiC)n interphases were deposited by pressure-Pulsed Chemical Vapor Deposition (P-CVD) on single filament Hi-Nicalon fibers and embedded in a SiC matrix sheath. The thicknesses of the carbide interphase sub-layers could be made as low as a few nanometers as evidenced by scanning and transmission electron microscopy. By using the P-ReactiveCVD method (P-RCVD), in which the TiC growth involves consumption of SiC, it was not only possible to obtain multilayered (SiC-TiC)n films but also TiC films with a porous multilayered microstructure as a result of the Kirkendall effect. The porosity in the TiC sequences was found to be enhanced when some PyC was added to SiC prior to total RCVD consumption. Because the porosity volume fraction was still not high enough, the role of mechanical fuse of the interphases could not be evidenced from the tensile curves, which remained fully linear even when chemical attack of the fiber surface was avoided.

  15. Effect of chemical fixatives on accurate preservation of Escherichia coli and Bacillus subtilis structure in cells prepared by freeze-substitution

    International Nuclear Information System (INIS)

    Graham, L.L.; Beveridge, T.J.

    1990-01-01

    Five chemical fixatives were evaluated for their ability to accurately preserve bacterial ultrastructure during freeze-substitution of select Escherichia coli and Bacillus subtilis strains. Radioisotopes were specifically incorporated into the peptidoglycan, lipopolysaccharide, and nucleic acids of E. coli SFK11 and W7 and into the peptidoglycan and RNA of B. subtilis 168 and W23. The ease of extraction of radiolabels, as assessed by liquid scintillation counting during all stages of processing for freeze-substitution, was used as an indicator of cell structural integrity and retention of cellular chemical composition. Subsequent visual examination by electron microscopy was used to confirm ultrastructural conformation. The fixatives used were: 2% (wt/vol) osmium tetroxide and 2% (wt/vol) uranyl acetate; 2% (vol/vol) glutaraldehyde and 2% (wt/vol) uranyl acetate; 2% (vol/vol) acrolein and 2% (wt/vol) uranyl acetate; 2% (wt/vol) gallic acid; and 2% (wt/vol) uranyl acetate. All fixatives were prepared in a substitution solvent of anhydrous acetone. Extraction of cellular constituents depended on the chemical fixative used. A combination of 2% osmium tetroxide-2% uranyl acetate or 2% gallic acid alone resulted in optimum fixation as ascertained by least extraction of radiolabels. In both gram-positive and gram-negative organisms, high levels of radiolabel were detected in the processing fluids in which 2% acrolein-2% uranyl acetate, 2% glutaraldehyde-2% uranyl acetate, or 2% uranyl acetate alone were used as fixatives. Ultrastructural variations were observed in cells freeze-substituted in the presence of different chemical fixatives. We recommend the use of osmium tetroxide and uranyl acetate in acetone for routine freeze-substitution of eubacteria, while gallic acid is recommended for use when microanalytical processing necessitates the omission of osmium

  16. Preparation and physico-chemical characterization of β-cyclodextrin incorporated chitosan biosorbent beads with potential environmental applications

    Science.gov (United States)

    Munim, Somayyah Abdul; Tahir Saddique, Muhammad; Raza, Zulfiqar Ali; Majeed, Muhammad Irfan

    2018-06-01

    Biosorption is one of the most efficient and feasible methods for eliminating noxious wastes from the aqueous systems. The use of non-hazardous, low-cost and biodegradable chitosan as a biosorbent is of significant importance in the above context. Present study was aimed to develop a β-cyclodextrin (β-CD) incorporated chitosan biosorbent in the form of beads. The prepared biosorbent beads were characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), x-ray diffraction (XRD) analysis, and thermo gravimetric analysis (TGA). The values of point of zero charge (PZC) of chitosan and β-CD incorporated chitosan beads were determined in the presence of an electrolyte by means of different methods including mass titration, salt addition and zeta potential ones. The SEM images exhibited roughened and porous morphologies which could enhance the adsorption of metal ions. The values of PZC of chitosan and β-CD incorporated chitosan biosorbent beads were found to be 6.38 and 7.12, respectively.

  17. Preparation of Cu2ZnSnS4 nano-crystalline powder by mechano-chemical method

    Science.gov (United States)

    Alirezazadeh, Farzaneh; Sheibani, Saeed; Rashchi, Fereshteh

    2018-01-01

    Copper zinc tin sulfide (Cu2ZnSnS4, CZTS) is one of the most promising ceramic materials as an absorber layer in solar cells due to its suitable band gap, high absorption coefficient and non-toxic and environmental friendly constituent elements. In this work, nano-crystalline CZTS powder was synthesized by mechanical milling. Elemental powders of Cu, Zn, Sn and were mixed in atomic ratio of 2:1:1:4 according to the stoichiometry of Cu2ZnSnS4 and then milled in a planetary high energy ball mill under argon atmosphere. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and diffusion reflectance spectroscopy (DRS). XRD results confirm the formation of single-phase CZTS with kesterite structure after 20 h of milling. Also, the mean crystallite size was about 35 nm. SEM results show that after 20 h of milling, the product has a relatively uniform particle size distribution. Optical properties of the product indicate that the band gap of prepared CZTS is 1.6 eV which is near to the optimum value for photovoltaic solar cells showing as a light absorber material in solar energy applications.

  18. Wet-Chemical Preparation of TiO2-Based Composites with Different Morphologies and Photocatalytic Properties

    Directory of Open Access Journals (Sweden)

    Liqin Xiang

    2017-10-01

    Full Text Available TiO2-based composites have been paid significant attention in the photocatalysis field. The size, crystallinity and nanomorphology of TiO2 materials have an important effect on the photocatalytic efficiency. The synthesis and photocatalytic activity of TiO2-based materials have been widely investigated in past decades. Based on our group’s research works on TiO2 materials, this review introduces several methods for the fabrication of TiO2, rare-earth-doped TiO2 and noble-metal-decorated TiO2 particles with different morphologies. We focused on the preparation and the formation mechanism of TiO2-based materials with unique structures including spheres, hollow spheres, porous spheres, hollow porous spheres and urchin-like spheres. The photocatalytical activity of urchin-like TiO2, noble metal nanoparticle-decorated 3D (three-dimensional urchin-like TiO2 and bimetallic core/shell nanoparticle-decorated urchin-like hierarchical TiO2 are briefly discussed.

  19. Preparation and use of chemically modified MCM-41 and silica gel as selective adsorbents for Hg(II) ions

    International Nuclear Information System (INIS)

    Puanngam, Mahitti; Unob, Fuangfa

    2008-01-01

    Adsorbents for Hg(II) ion extraction were prepared using amorphous silica gel and ordered MCM-41. Grafting with 2-(3-(2-aminoethylthio)propylthio)ethanamine was used to functionalize the silica. The functionalized adsorbents were characterized by nitrogen adsorption, X-ray diffraction, 13 C MAS NMR spectroscopy and thermogravimetric analysis. The adsorption properties of the modified silica gel and MCM-41 were compared using batch method. The effect of pH, stirring time, ionic strength and foreign ions were studied. The extraction of Hg(II) ions occurred rapidly with the modified MCM-41 and the optimal pH range for the extraction by the modified materials was pH 4-7. Foreign ions, especially Cl - had some effect on the extraction efficiency of the modified silica gel and the modified MCM-41. The adsorption behavior of both adsorbents could be described by a Langmuir model at 298 K, and the maximum adsorption capacity of the modified silica gel and MCM-41 at pH 3 was 0.79 and 0.70 mmol g -1 , respectively. The modified MCM-41 showed a larger Langmuir constant than that of the modified silica gel, indicating a better ability for Hg(II) ion adsorption. The results indicate that the structure of the materials affects the adsorption behavior. These materials show a potential for the application as effective and selective adsorbents for Hg(II) removal from water

  20. Sensory and physico-chemical characteristics of desserts prepared with egg products processed by freeze and spray drying

    Directory of Open Access Journals (Sweden)

    Marcelo Nunes de Jesús

    2013-09-01

    Full Text Available In this work, three freeze-dried (FD egg products (whole egg (WE, egg yolk (EY and egg white (EW were obtained and the acceptability of confections prepared with each was evaluated. Sensory analyses for confections were performed by hedonic testing with fifty panelists in each evaluation. The studied confections were: Condensed Milk Pudding (P, Quindim (Q and Meringue (M. The results obtained for confections made with FD egg products were compared with the achieved through other formulations of the same desserts made with fresh (F or spray-dried (SD egg products. The sensory analysis results for confections made with FD egg products showed good acceptance by panelists. A principal component analysis of the sensory evaluation data was carried out to identify similarities between the different egg products. The PCA supported the conclusion that FD egg products can substitute their fresh and SD counterparts in dessert formulations with good acceptability while keeping the advantages conferred by the freeze-drying method.

  1. Development of preparative and analytical methods of the hop bitter acid oxide fraction and chemical properties of its components.

    Science.gov (United States)

    Taniguchi, Yoshimasa; Matsukura, Yasuko; Taniguchi, Harumi; Koizumi, Hideki; Katayama, Mikio

    2015-01-01

    The bitter acids in hops (Humulus lupulus L.) and beer, such as α-, β-, and iso-α-acids, are known to affect beer quality and display various physiological effects. However, these compounds readily oxidize, and the effect of the oxides on the properties of beer or their potential health benefits are not well understood. In this study, we developed a simple preparative method for the bitter acid oxide fraction derived from hops and designated the constituents as matured hop bitter acids (MHBA). HPLC-PDA-ESI/HRMS and MS(2) revealed that MHBA are primarily composed of α-acid-derived oxides, which possess a common β-tricarbonyl moiety in their structures similar to α-, β-, and iso-α-acids. We also developed a quantitative analytical method of whole MHBA by HPLC, which showed high precision and reproducibility. Using our newly developed method, the concentration of whole MHBA in several commercial beers was evaluated. Our results will promote the study of bitter acid oxides.

  2. Method of preparation of a CO.sub.2 removal sorbent with high chemical stability during multiple cycles

    Science.gov (United States)

    Siriwardane, Ranjani V.; Rosencwaig, Shira

    2015-07-14

    Method for the production of a clay-alkali-amine CO.sub.2 sorbent prepared by integrating a clay substrate, basic alkali salt, and amine liquid. The basic alkali salt is present relative to the clay substrate in a weight ratio of from about 1 part to about 50 parts per 100 parts of the clay substrate. The amine liquid is present relative to a clay-alkali combination in a weight ratio of from about 1 part to about 10 parts per 10 parts of the clay-alkali combination. The clay substrate and basic alkali salt may be combined in a solid-solid heterogeneous mixture and followed by introduction of the amine liquid. Alternatively, an alkaline solution may be blended with the amine solution prior to contacting the clay substrate. The clay-alkali-amine CO.sub.2 sorbent is particularly advantageous for low temperature CO.sub.2 removal cycles in a gas stream having a CO.sub.2 concentration less than around 2000 ppm and an oxygen concentration around 21%, such as air. Results are presented illustrating the performance of the clay-alkali-amine CO.sub.2 sorbent compared to a clay-amine sorbent lacking the alkali inclusion.

  3. Chemical compositions and antioxidant/antimicrobial activities of various samples prepared from Schinus terebinthifolius leaves cultivated in Egypt.

    Science.gov (United States)

    El-Massry, Khaled F; El-Ghorab, Ahmed H; Shaaban, Hamdy A; Shibamoto, Takayuki

    2009-06-24

    Essential oil, dichloromethane extract, and ethanol extract were prepared from fresh Schinus terebinthifolius leaves cultivated in Egypt. The essential oil was analyzed by gas chromatography and gas chromatography/mass spectrometry. The essential oil comprised 4.97% monoterpenes, 56.96% sesquiterpenes, 34.37% oxygenated monoterpenes, and 3.32% oxygenated sesquiterpenes. The major compounds in the essential oil were cis-beta-terpineol (GC peak area%, 17.87%), (E)-caryophyllene (17.56%), beta-cedrene (9.76%), and citronellal (7.03%). The major phenolic compounds identified in the ethanol extract were caffeic acid (5.07 mg/100 mg extract), coumaric acid (1.64 mg), and syringic acid (1.59 mg). The antioxidant activity of ethanol extract, which was comparable with that of butylhydroquinone, was superior to essential oil and dichloromethane extract in 2,2-diphenylpicrylhydrazyl and beta-carotene/bleaching assays. The dichloromethane extract exhibited the greatest antimicrobial activity against 6 strains, followed by the ethanol extract and the essential oil.

  4. Evaluation of the structural, optical and electrical properties of AZO thin films prepared by chemical bath deposition for optoelectronics

    Science.gov (United States)

    Kumar, K. Deva Arun; Valanarasu, S.; Rosario, S. Rex; Ganesh, V.; Shkir, Mohd.; Sreelatha, C. J.; AlFaify, S.

    2018-04-01

    Aluminum doped zinc oxide (AZO) thin films for electrode applications were deposited on glass substrates using chemical bath deposition (CBD) method. The influence of deposition time on the structural, morphological, and opto-electrical properties of AZO films were investigated. Structural studies confirmed that all the deposited films were hexagonal wurtzite structure with polycrystalline nature and exhibited (002) preferential orientation. There is no other impurity phases were detected for different deposition time. Surface morphological images shows the spherically shaped grains are uniformly arranged on to the entire film surface. The EDS spectrum confirms the presence of Zn, O and Al elements in deposited AZO film. The observed optical transmittance is high (87%) in the visible region, and the calculated band gap value is 3.27 eV. In this study, the transmittance value is decreased with increasing deposition time. The room temperature PL spectrum exposed that AZO thin film deposited at (60 min) has good optical quality with less defect density. The minimum electrical resistivity and maximum carrier concentration values were observed as 8.53 × 10-3(Ω cm) and 3.53 × 1018 cm-3 for 60 min deposited film, respectively. The obtained figure of merit (ϕ) value 3.05 × 10-3(Ω/sq)- 1 is suggested for an optoelectronic device.

  5. Structural and optical studied of nano structured lead sulfide thin films prepared by the chemical bath deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Al Din, Nasser Saad, E-mail: nsaadaldin@yahoo.com; Hussain, Nabiha, E-mail: nabihahssin@yahoo.com [Damascus University Faculty of Science, Department of physics, Homs (Syrian Arab Republic); Jandow, Nidhal, E-mail: nidhaljandow@yahoo.com [Al –Mustansiriyah University, College of Education, Department of physics, Baghdad (Iraq)

    2016-07-25

    Lead (II) Sulfide PbS thin films were deposited on glass substrates at 25°C by chemical bath deposition (CBD) method. The structural properties of the films were studied as a function of the concentration of Thiourea (CS (NH{sub 2}){sub 2}) as Source of Sulfide and deposition time. The surface morphology of the films was characterized by X-ray diffraction and SEM. The obtained results showed that the as-deposited films Polycrystalline had cubic crystalline phase that belong to S.G: Fm3m. We found that they have preferred orientation [200]. Also the thickness of thin films decrease with deposition time after certain value and, it observed free sulfide had orthorhombic phase. Optical properties showed that the thin films have high transmission at visible range and low transmission at UV, IR range. The films of PbS have direct band gap (I.68 - 2.32 ev) at 300 K the values of band energy decreases with increases thickness of the Lead (II) Sulfide films.

  6. High-aspect-ratio and high-flatness Cu3(SiGe) nanoplatelets prepared by chemical vapor deposition.

    Science.gov (United States)

    Klementová, Mariana; Palatinus, Lukás; Novotný, Filip; Fajgar, Radek; Subrt, Jan; Drínek, Vladislav

    2013-06-01

    Cu3(SiGe) nanoplatelets were synthesized by low-pressure chemical vapor deposition of a SiH3C2H5/Ge2(CH3)6 mixture on a Cu-substrate at 500 degrees C, total pressure of 110-115 Pa, and Ge/Si molar ratio of 22. The nanoplatelets with composition Cu76Si15Ge12 are formed by the 4'-phase, and they are flattened perpendicular to the [001] direction. Their lateral dimensions reach several tens of micrometers in size, but they are only about 50 nm thick. Their surface is extremely flat, with measured root mean square roughness R(q) below 0.2 nm. The nanoplatelets grow via the non-catalytic vapor-solid mechanism and surface growth. In addition, nanowires and nanorods of various Cu-Si-Ge alloys were also obtained depending on the experimental conditions. Morphology of the resulting Cu-Si-Ge nanoobjects is very sensitive to the experimental parameters. The formation of nanoplatelets is associated with increased amount of Ge in the alloy.

  7. Current flow mechanism in Cu{sub 2}O/p-Si heterojunction prepared by chemical method

    Energy Technology Data Exchange (ETDEWEB)

    Serin, T; Guerakar, S; Serin, N; Yildirim, N; Oezyurt Kus, F, E-mail: serin@eng.ankara.edu.t [Department of Engineering Physics, Faculty of Engineering, Ankara University, 06100 Ankara (Turkey)

    2009-11-21

    Cu{sub 2}O thin films were chemically deposited on single-crystal p-Si substrates to form Cu{sub 2}O/p-Si heterojunctions. The structure of the Cu{sub 2}O films was analysed by x-ray diffraction spectroscopy and UV-Vis-NIR transmittance spectra. In order to investigate the dark current transport mechanism in Cu{sub 2}O/p-Si heterojunctions the current-voltage characteristics were measured in the temperature range 120-320 K and capacitance-voltage characteristics at a high frequency of {approx}1 MHz at room temperature. The I-V-T characteristics revealed that the forward current was determined by trap-assisted multi-step tunnelling. The activation energy determined from the saturation current and the junction built-in potential determined from the capacitance-voltage characteristics were about 0.18 eV and 1.10 V at room temperature, respectively.

  8. Structural, morphological, wettability and thermal resistance properties of hydro-oleophobic thin films prepared by a wet chemical process

    International Nuclear Information System (INIS)

    Phani, A.R.

    2006-01-01

    The structural properties of fluorine containing polymer compounds make them highly attractive materials for hydro-oleophobic applications. However, most of these exhibit low surface energy and poor adhesion on the substrates. In the present investigation, crack free, smooth and uniform thin films of poly[4,5-difluoro-2,2-bis(trifluoromethyl)-1,3-dioxole] -co-tetrafluoroethylene (TFD-co-TFE) with good adhesion have been deposited by wet chemical spin-coating technique on polished AISI 440C steel substrates. The as-deposited films (xerogel films) have been subjected to annealing for 1 h at different temperatures ranging from 100 to 500 deg. C in an argon atmosphere. The size growth of the nano-hemispheres increased from 8 nm for xerogel film to 28 nm for film annealed at 400 deg. C. It was found that as the annealing temperature increased from 100 to 400 deg. C, nano-hemisphere-like structures were formed, which in turn have shown increase in the water contact angle from 122 deg. to 147 deg. and oil (peanut) contact angle from 85 deg. to 96 deg. No change in the water contact angle (122 deg.) has been observed when the films deposited at room temperature were heated in air from 30 to 80 deg. C as well as exposed to steam for 8 days for 8 h/day indicating thermal stability of the film

  9. Influence of the doping level on the porosity of silicon nanowires prepared by metal-assisted chemical etching

    International Nuclear Information System (INIS)

    Geyer, Nadine; Wollschläger, Nicole; Tonkikh, Alexander; Berger, Andreas; Werner, Peter; Fuhrmann, Bodo; Leipner, Hartmut S; Jungmann, Marco; Krause-Rehberg, Reinhard

    2015-01-01

    A systematic method to control the porosity of silicon nanowires is presented. This method is based on metal-assisted chemical etching (MACE) and takes advantage of an HF/H_2O_2 etching solution and a silver catalyst in the form of a thin patterned film deposited on a doped silicon wafer. It is found that the porosity of the etched nanowires can be controlled by the doping level of the wafer. For low doping concentrations, the wires are primarily crystalline and surrounded by only a very thin layer of porous silicon (pSi) layer, while for highly doped silicon, they are porous in their entire volume. We performed a series of controlled experiments to conclude that there exists a well-defined critical doping concentration separating the crystalline and porous regimes. Furthermore, transmission electron microscopy investigations showed that the pSi has also a crystalline morphology on a length scale smaller than the pore size, determined from positron annihilation lifetime spectroscopy to be mesoscopic. Based on the experimental evidence, we devise a theoretical model of the pSi formation during MACE and apply it for better control of the nanowire morphology. (paper)

  10. Hybrid graphene oxide/DAB-Am-16 dendrimer: Preparation, characterization chemical reactivity and their electrocatalytic detection of L-Dopamine

    Science.gov (United States)

    Do Carmo, Devaney Ribeiro; Fernandes, Daniela Silvestrini

    2017-09-01

    Graphene oxide (GO) was chemically modified with a poly(propylene)imine Generation 3.0 dendrimer (DAB-Am-16). The characterization, structure and properties of hybrid graphene oxide/DAB-Am-16 dendrimer was studied by Raman spectroscopy, Fourier-Transforming Infrared Spectroscopy (FT-IR), X-Ray Photoelectron Spectroscopic (XPS), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Thermogravimetric analysis. After functionalized the hybrid material (GOD) can interact with copper and subsequently with hexacyanoferrate (III) ions (GODHCu). The GODHCu incorporated into a graphite paste electrode (20% w/w) was applied to an electrocatalytic detection of neurotransmitter L-dopamine using differential pulse voltammetry. The analytical curve showed a linear response in the concentration range from 1.0 × 10-7 to 1.0 × 10-5 mol L-1 with a corresponding equation Y(A) = 1.706 × 10-5 + 0.862 [L-dopamine] and a correlation coefficient r2 = 0.998. The detection limit was 6.36 × 10-7 mol L-1 with a relative standard deviation of ±4% (n = 3) and an amperometric sensitivity of 0.862 A/mol L-1.

  11. Influence of the precursors in the chemical preparation of γ - Al2O3 in reactions of alcohols dehydration

    International Nuclear Information System (INIS)

    Salmones, J.; Limon, M.T.; Mayagoitia, V.; Rojas, F.; Kornhauser, I.; Morales, J.; Acosta, D.

    1998-01-01

    A chemical method for the synthesis of alumina substrates based on a microscopic morphological control, is presented. The influence of the precursor alcohol used for the synthesis of Al(OR) 3 is studied too. This latter compound is the raw material to synthesize the alumina materials treated here. The effects of alcohols such as ethanol, isopropanol and ter butanol are analyzed. Results show that an early formation (i.e. at low temperature) of the porous structure is reached in the case of γ -Al 2 O 3 synthesized from ethanol. On the other hand, pore formation for alumina obtained from isopropanol and ter butanol, occurs until appearance of the γ phase (at approximately 500 Centigrade). The different alumina substrates were used as catalysts in dehydration reactions of primary, secondary and tertiary alcohols. Decreasing catalytic activity corresponds to the sequence: (R-OH) 3 2 2 3 . These results are explained by means of a reaction mechanism which is associated with the textural properties of the catalysts. (Author)

  12. Preparation of Hydrophobic Metal-Organic Frameworks via Plasma Enhanced Chemical Vapor Deposition of Perfluoroalkanes for the Removal of Ammonia

    Science.gov (United States)

    DeCoste, Jared B.; Peterson, Gregory W.

    2013-01-01

    Plasma enhanced chemical vapor deposition (PECVD) of perfluoroalkanes has long been studied for tuning the wetting properties of surfaces. For high surface area microporous materials, such as metal-organic frameworks (MOFs), unique challenges present themselves for PECVD treatments. Herein the protocol for development of a MOF that was previously unstable to humid conditions is presented. The protocol describes the synthesis of Cu-BTC (also known as HKUST-1), the treatment of Cu-BTC with PECVD of perfluoroalkanes, the aging of materials under humid conditions, and the subsequent ammonia microbreakthrough experiments on milligram quantities of microporous materials. Cu-BTC has an extremely high surface area (~1,800 m2/g) when compared to most materials or surfaces that have been previously treated by PECVD methods. Parameters such as chamber pressure and treatment time are extremely important to ensure the perfluoroalkane plasma penetrates to and reacts with the inner MOF surfaces. Furthermore, the protocol for ammonia microbreakthrough experiments set forth here can be utilized for a variety of test gases and microporous materials. PMID:24145623

  13. Vertically aligned Si nanocrystals embedded in amorphous Si matrix prepared by inductively coupled plasma chemical vapor deposition (ICP-CVD)

    Energy Technology Data Exchange (ETDEWEB)

    Nogay, G. [Department of Physics, Middle East Technical University (METU), Ankara 06800 (Turkey); Center of Solar Energy Research and Application (GÜNAM), Middle East Technical University (METU), Ankara 06800 (Turkey); Saleh, Z.M., E-mail: zaki.saleh@aauj.edu [Center of Solar Energy Research and Application (GÜNAM), Middle East Technical University (METU), Ankara 06800 (Turkey); Department of Physics, Arab American University–Jenin (AAUJ), Jenin, Palestine (Country Unknown); Özkol, E. [Center of Solar Energy Research and Application (GÜNAM), Middle East Technical University (METU), Ankara 06800 (Turkey); Department of Chemical Engineering, Middle East Technical University (METU), Ankara 06800 (Turkey); Turan, R. [Department of Physics, Middle East Technical University (METU), Ankara 06800 (Turkey); Center of Solar Energy Research and Application (GÜNAM), Middle East Technical University (METU), Ankara 06800 (Turkey)

    2015-06-15

    Highlights: • Inductively-coupled plasma is used for nanostructured silicon at room temperature. • Low temperature deposition allows device processing on various substrates. • Deposition pressure is the most effective parameter in controlling nanostructure. • Films consist of quantum dots in a-Si matrix and exhibit columnar vertical growth. • Films are porous to oxygen infusion along columnar grain boundaries. - Abstract: Vertically-aligned nanostructured silicon films are deposited at room temperature on p-type silicon wafers and glass substrates by inductively-coupled, plasma-enhanced chemical vapor deposition (ICPCVD). The nanocrystalline phase is achieved by reducing pressure and increasing RF power. The crystalline volume fraction (X{sub c}) and the size of the nanocrystals increase with decreasing pressure at constant power. Columnar growth of nc-Si:H films is observed by high resolution transmission electron microscopy (HRTEM) and scanning electron microscopy (SEM). The films exhibit cauliflower-like structures with high porosity that leads to slow but uniform oxidation after exposure to air at room temperature. Films deposited at low pressures exhibit photoluminescence (PL) signals that may be deconvoluted into three distinct Gaussian components: 760–810, 920–935, and 990–1000 nm attributable to the quantum confinement and interface defect states. Hydrogen dilution is manifested in significant enhancement of the PL, but it has little effect on the nanocrystal size and X{sub c}.

  14. Fast preparation of Na0.44MnO2 nanorods via a high NaOH concentration hydrothermal soft chemical reaction and their lithium storage properties

    International Nuclear Information System (INIS)

    Liu, Cai; Li, Jiangang; Zhao, Pengxiang; Guo, Wenli; Yang, Xiaoping

    2015-01-01

    This paper describes a high NaOH concentration hydrothermal soft chemical reaction to prepare Na 0.44 MnO 2 nanorods. In this process, Na-birnessite precursors and concentrated NaOH solution are introduced into the hydrothermal reaction. As a result, the hydrothermal time can be significantly shortened from 96 to 24 h, the hydrothermal temperature can be reduced from 205 to 180 °C and the yield of Na 0.44 MnO 2 can be increased from about 0.6 to about 2.4 g/(mL . day), respectively. Furthermore, the obtained Na 0.44 MnO 2 nanorods with one-dimensional tunnel structures exhibit favorable electrochemical lithium storage properties, which make them promising for the cathode materials of lithium-ion batteries

  15. Room Temperature Gas Sensing Properties of Sn-Substituted Nickel Ferrite (NiFe2O4) Thin Film Sensors Prepared by Chemical Co-Precipitation Method

    Science.gov (United States)

    Manikandan, V.; Li, Xiaogan; Mane, R. S.; Chandrasekaran, J.

    2018-04-01

    Tin (Sn) substituted nickel ferrite (NiFe2O4) thin film sensors were prepared by a simple chemical co-precipitation method, which initially characterized their structure and surface morphology with the help of x-ray diffraction and scanning electron microscopy. Surface morphology of the sensing films reveals particles stick together with nearer particles and this formation leads to a large specific area as a large specific area is very useful for easy adsorption of gas molecules. Transmission electron microscopy and selected area electron diffraction pattern images confirm particle size and nanocrystallnity as due to formation of circular rings. Fourier transform infrared analysis has supported the presence of functional groups. The 3.69 eV optical band gap of the film was found which enabled better gas sensing. Gas sensors demonstrate better response and recovery characteristics, and the maximum response was 68.43%.

  16. The role of MgCl2 compounds in preparation of Tin oxide micro particles by one-step solid - state chemical reaction method and characterization of microstructure

    International Nuclear Information System (INIS)

    Hojabry, A.; Rezainik, Y.; Abdoljavad, N.; Moghimi, N.; Shakib, M.

    2007-01-01

    In this paper, Tin oxide (SnO 2 ) nano crystals have been synthesized by one-step solid-state chemical reactions method. In the first step, the powder of SnCl 4 . 5H 2 O was mixed with MgCl 2 and Mg(OH) 2 with a weight ratio of Sn to Mg (2:1) in the air atmosphere at room, and then annealed at 200 d egree C , 400 d egree C and 600 d egree C in air for 4 h to give different size of nanoparticles. This method is a simple, efficient and economic preparation for SnO 2 nanoparticles with adjustable grain sizes in the range of 7-32 nm in high yield. The microstructure and morphology of SnO 2 nanoparticles have been studied by X-ray diffraction (XRD), scanning electron microscopy and thermal analysis (thermogravimetric analysis -differential thermal analysis).

  17. Multiwall carbon nanotubes chemically modified carbon paste electrodes for determination of gentamicin sulfate in pharmaceutical preparations and biological fluids

    Energy Technology Data Exchange (ETDEWEB)

    Khalil, M.M., E-mail: magdy_mmagdy@yahoo.com; Abed El-aziz, G.M., E-mail: Gamal_abedelaziz@yahoo.com

    2016-02-01

    This article focused on the construction and characteristics of novel and sensitive gentamicin carbon paste electrodes which are based on the incorporation of multiwall carbon nanotubes (MWCNTs) which improve the characteristics of the electrodes. The electrodes were constructed based on gentamicin-phosphotungstate (GNS-PTA) called CPE{sub 1}, gentamicin-phosphomolybdate (GNS-PMA) called CPE{sub 2}, GNS-PTA + MWMCNTs called MWCPE{sub 1}, and GNS-PMA + MWMCNTs called MWCPE{sub 2}. The constructed electrodes, at optimum paste composition, exhibited good Nernstian response for determination of gentamicin sulfate (GNS) over a linear concentration range from 2.5 × 10{sup −6} to 1 × 10{sup −2}, 3.0 × 10{sup −6} to 1 × 10{sup −2}, 4.9 × 10{sup −7} to 1 × 10{sup −2} and 5.0 × 10{sup −7} to 1 × 10{sup −2} mol L{sup −1}, with lower detection limit 1 × 10{sup −6}, 1 × 10{sup −6}, 1.9 × 10{sup −7} and 2.2 × 10{sup −7} mol L{sup −1}, and with slope values of 29.0 ± 0.4, 29.2 ± 0.7, 31.2 ± 0.5 and 31.0 ± 0.6 mV/decade for CPE{sub 1}, CPE{sub 2}, MWCPE{sub 1} and MWCPE{sub 2}, respectively. The response of electrodes is not affected by pH in the range 3–8 for CPE{sub 1} and CPE{sub 2} and in the range 2.5–8.5 for MWCPE{sub 1} and MWCPE{sub 2}. The results showed fast dynamic response time (about 8–5 s) and long lifetime (more than 2 months) for all electrodes. The sensors showed high selectivity for gentamicin sulfate (GNS) with respect to a large number of interfering species. The constructed electrodes were successfully applied for determination of GNS in pure form, its pharmaceutical preparations and biological fluids using standard addition and potentiometric titration methods with high accuracy and precision. - Graphical abstract: The incorporation of MWCNTs in paste composition improves the characteristics of the MWCPE electrodes which show better responses in terms of sensitivity, Nernstian slope, linear range, faster

  18. Chemical composition of protein concentrate prepared from Yellowfin tuna Thunnus albacares roe by cook-dried process

    Directory of Open Access Journals (Sweden)

    Hyun Ji Lee

    2016-05-01

    Full Text Available Abstract Roe is the term used to describe fish eggs (oocytes gathered in skeins and is one of the most valuable food products from fishery sources. Thus, means of processing are required to convert the underutilized yellowfin tuna roes (YTR into more marketable and acceptable forms as protein concentrate. Roe protein concentrates (RPCs were prepared by cooking condition (boil-dried concentrate, BDC and steam-dried concentrate, SDC, respectively and un-cooking condition (freeze-dried concentrate, FDC from yellowfin tuna roe. The yield of RPCs was in the range from 22.2 to 25.3 g/100 g of roe. RPCs contained protein (72.3–77.3 %, moisture (4.3–5.6 %, lipid (10.6–11.3 % and ash (4.3–5.7 % as the major constituents. The prominent amino acids of RPCs were aspartic acid, 8.7–9.2, glutamic acid, 13.1–13.2, and leucine, 8.5–8.6 g/100 g of protein. Major differences were not observed in each of the amino acid. K, S, Na, and P as minerals were the major elements in RPCs. No difference noted in sodium dodecyl sulfate polyacrylamide gel electrophoresis protein band (15–100 K possibly representing partial hydrolysis of myosin. Therefore, RPCs from YTR could be use potential protein ingredient for human food and animal feeds.

  19. Phase-controlled preparation of TiO{sub 2} films and micro(nano)spheres by low-temperature chemical bath deposition

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Mingsong, E-mail: wangms@mail.ujs.edu.cn [School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013 (China); Li, Qihui; Yu, Haiyan [School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013 (China); Hur, Seung Hyun [Department of Chemical Engineering, University of Ulsan, Ulsan 680-749 (Korea, Republic of); Kim, Eui Jung, E-mail: ejkim@ulsan.ac.kr [Department of Chemical Engineering, University of Ulsan, Ulsan 680-749 (Korea, Republic of)

    2013-11-25

    Highlights: •Simultaneously preparation of TiO{sub 2} films and sphere-like precipitates by low-temperature chemical bath deposition. •The same building blocks observed in the films and precipitates. •Cluster-by-cluster attachment is succeeded by the ion-by-ion growth. •Phase-controlled growth of TiO{sub 2} by the effects of solvent or fluorine ion. -- Abstract: TiO{sub 2} films and micro(nano)spheres have been simultaneously prepared by means of low-temperature chemical bath deposition (CBD). The films and precipitates are found to be constructed of the same building blocks regardless of the bath conditions. Thin nanosheets of ca. 20 nm in thickness serve as the building blocks of rutile TiO{sub 2} grown in an acidic bath. They aggregate to form spheres to reduce the surface energy of the precipitates, while in the films they grow into discrete crystallites on the seeded substrate. Fine control over the crystalline phase of TiO{sub 2} is achieved by replacing some water with ethanol or the addition of NH{sub 4}F. A gradual transition from rutile to anatase is observed as the ethanol and NH{sub 4}F contents are increased. Moreover, the crystallite size of TiO{sub 2} is significantly reduced and there exists monodisperse nanoparticles and aggregate microspheres in the products modified with ethanol and NH{sub 4}F, respectively. This size-dependent phase transition is consistent with previous theoretical and thermodynamic studies. The facile tune of the TiO{sub 2} phase by low-temperature CBD method may be useful to improve the performance of TiO{sub 2} for its various applications.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-10-15

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

  1. Multiwall carbon nanotubes chemically modified carbon paste electrodes for determination of gentamicin sulfate in pharmaceutical preparations and biological fluids.

    Science.gov (United States)

    Khalil, M M; Abed El-Aziz, G M

    2016-02-01

    This article focused on the construction and characteristics of novel and sensitive gentamicin carbon paste electrodes which are based on the incorporation of multiwall carbon nanotubes (MWCNTs) which improve the characteristics of the electrodes. The electrodes were constructed based on gentamicin-phosphotungstate (GNS-PTA) called CPE1, gentamicin-phosphomolybdate (GNS-PMA) called CPE2, GNS-PTA+ MWMCNTs called MWCPE1, and GNS-PMA+ MWMCNTs called MWCPE2. The constructed electrodes, at optimum paste composition, exhibited good Nernstian response for determination of gentamicin sulfate (GNS) over a linear concentration range from 2.5×10(-6) to 1×10(-2), 3.0×10(-6) to 1×10(-2), 4.9×10(-7) to 1×10(-2) and 5.0×10(-7) to 1×10(-2)molL(-1), with lower detection limit 1×10(-6), 1×10(-6), 1.9×10(-7) and 2.2×10(-7)molL(-1), and with slope values of 29.0±0.4, 29.2±0.7, 31.2±0.5 and 31.0±0.6mV/decade for CPE1, CPE2, MWCPE1 and MWCPE2, respectively. The response of electrodes is not affected by pH in the range 3-8 for CPE1 and CPE2 and in the range 2.5-8.5 for MWCPE1 and MWCPE2. The results showed fast dynamic response time (about 8-5s) and long lifetime (more than 2months) for all electrodes. The sensors showed high selectivity for gentamicin sulfate (GNS) with respect to a large number of interfering species. The constructed electrodes were successfully applied for determination of GNS in pure form, its pharmaceutical preparations and biological fluids using standard addition and potentiometric titration methods with high accuracy and precision. Published by Elsevier B.V.

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

    Directory of Open Access Journals (Sweden)

    Dejan Verhovšek

    2012-01-01

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

  3. Preparation and characterization of poly(acrylic acid)—corn starch blend for use as chemical sand-fixing materials

    Science.gov (United States)

    Dang, Xugang; Chen, Hui; Shan, Zhihua

    2017-07-01

    One chemical sand-fixing materials based on poly(acrylic acid)-corn starch (PACS) blend was studied in this work. The PACS blend was prepared by solution mixing method between PA and CS. In order to prepare sand-fixing materials for environmental applications using the well-established method of spraying evenly PACS blend solution on the surfaces of fine sand. Fourier transform infrared spectroscopy (FT-IR) revealed the existence of the intermolecular interactions between the blend components. Scanning electron microscope (SEM) analysis showed a continuous phase of blend, and it also showed the good sand-fixing capacity. The test results of hygroscopicity and water retention experiments indicated that the blends had excellent water-absorbing and water-retention capacity. The results of contact angle measurements between the PACS solutions and fine sand showed that the PACS blend has a satisfactory effect on fine sand wetting. And the PACS, as a sand-fixation material, has excellent sand-fixation rate up to 99.5%.

  4. One-step liquid phase chemical method to prepare carbon-based amorphous molybdenum sulfides: As the effective hydrogen evolution reaction catalysts

    International Nuclear Information System (INIS)

    Guo, Mengmeng; Wu, Qikang; Yu, Miaomiao; Wang, Yinling; Li, Maoguo

    2017-01-01

    Two different kinds of carbon-based amorphous molybdenum sulfide composite catalysts (activated carbon supported amorphous molybdenum sulfide and acetylene black supported amorphous molybdenum sulfide) had been prepared in a facile and scalable one-step liquid phase chemical method. The morphological and structural information of catalysts was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-Ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and it’s electro-catalytic HER activity were evaluated by linear sweep voltammetry(LSV), amperometric i-t technology and AC impedance technology. The as-prepared carbon-based amorphous molybdenum sulfides showed greatly enhanced electro-catalytic activity for HER compared with pure amorphous molybdenum sulfides. Especially, the nano-sized acetylene black supported molybdenum sulfide exhibited excellent electro-catalytic HER performances with a low onset potential of −116 mV versus reverse hydrogen electrode (RHE) and a small Tafel slope of 51 mV per decade.

  5. The effect of thermal annealing on the optical band gap of cadmium sulphide thin films, prepared by the chemical bath deposition technique

    International Nuclear Information System (INIS)

    Ampong, F. K.; Boakye, F.; Asare Donkor, N. K.

    2010-01-01

    Cadmium sulphide thin films have been prepared by the chemical bath deposition technique (ph 11, 70 degree centigrade). Two different sets of films were prepared under varied conditions and concentrations of their ions sources (Cd 2+ from cadmium nitrate, S 2- from thiourea) and Na 2 EDTA as a complexing agent. A UV mini-Schimazu UV-VIS Spectrophotometer was used to determine the optical absorbance of the films as a function of wavelength at room temperature over the wavelength range 200 - 600 nm. The samples were then thermally annealed for thirty minutes, at temperatures of 100 degree centigrade, and 200 degree centigrade, after which the absorbance of the films were again recorded. The band gap values obtained for the sample with 0.5 M CdS as deposited, annealed at 100 degree centigrade and 200 degree centigrade were 2.1 eV, 2.2 eV and 2.3 eV respectively. Whilst the values obtained for the sample 0.15 CdS as deposited, annealed at 100 degree centigrade and annealed at 200 degree centigrade were 2.0 eV, 2.01 eV and 2.02 eV respectively. The increase in band gap with annealing temperature might be attributed to the improvement in crystallinity in the films. (au)

  6. Rare earths: preparation of spectro chemically pure standards, study of their carbonates and synthesis of a new compound series - the peroxy carbonates

    International Nuclear Information System (INIS)

    Queiroz, Carlos Alberto da Silva

    1996-05-01

    In this work the following studies are concerned: I) preparation of lanthanum, cerium, praseodymium, neodymium and samarium oxides for use as spectro chemically pure standards; II) behavior of the rare earth (La, Ce, Pr, Nd, Sm) carbonates soluble in ammonium carbonate and mixture of ammonium carbonate/ammonium hydroxide, and III) synthesis and characterization of rare earth peroxy carbonates - a new series of compounds. Data for the synthesis and characterization of the rare earths peroxy carbonates described for the first time in this work are presented and discussed. With the aid of thermal analysis (TG-DTG) the thermal stability and the stoichiometric composition for new compounds were established and a mechanism of thermal decomposition was proposed. The peroxy carbonate was prepared by the addition of hydrogen peroxyde to the complexed soluble rare earths carbonates. These studies included also the determinations of active oxygen, the total rare earth oxide by gravimetry and complexometry and the C, H and N contents by microanalysis. The new compounds were also investigated by infrared spectroscopy. (author)

  7. Automated radioanalytical system incorporating microwave-assisted sample preparation, chemical separation, and online radiometric detection for the monitoring of total 99Tc in nuclear waste processing streams.

    Science.gov (United States)

    Egorov, Oleg B; O'Hara, Matthew J; Grate, Jay W

    2012-04-03

    An automated fluidic instrument is described that rapidly determines the total (99)Tc content of aged nuclear waste samples, where the matrix is chemically and radiologically complex and the existing speciation of the (99)Tc is variable. The monitor links microwave-assisted sample preparation with an automated anion exchange column separation and detection using a flow-through solid scintillator detector. The sample preparation steps acidify the sample, decompose organics, and convert all Tc species to the pertechnetate anion. The column-based anion exchange procedure separates the pertechnetate from the complex sample matrix, so that radiometric detection can provide accurate measurement of (99)Tc. We developed a preprogrammed spike addition procedure to automatically determine matrix-matched calibration. The overall measurement efficiency that is determined simultaneously provides a self-diagnostic parameter for the radiochemical separation and overall instrument function. Continuous, automated operation was demonstrated over the course of 54 h, which resulted in the analysis of 215 samples plus 54 hly spike-addition samples, with consistent overall measurement efficiency for the operation of the monitor. A sample can be processed and measured automatically in just 12.5 min with a detection limit of 23.5 Bq/mL of (99)Tc in low activity waste (0.495 mL sample volume), with better than 10% RSD precision at concentrations above the quantification limit. This rapid automated analysis method was developed to support nuclear waste processing operations planned for the Hanford nuclear site.

  8. Effect of Nitrogen Content on Physical and Chemical Properties of TiN Thin Films Prepared by DC Magnetron Sputtering with Supported Discharge

    Science.gov (United States)

    Kavitha, A.; Kannan, R.; Gunasekhar, K. R.; Rajashabala, S.

    2017-10-01

    Amorphous titanium nitride (TiN) thin films have been prepared on silicon (Si) and glass substrates by direct-current (DC) reactive magnetron sputtering with a supported discharge (triode). Nitrogen gas (N2) at partial pressure of 0.3 Pa, 0.4 Pa, 0.5 Pa, and 0.6 Pa was used to prepare the TiN thin films, maintaining total pressure of argon and N2 of about 0.7 Pa. The chemical, microstructural, optical, and electrical properties of the TiN thin films were systematically studied. Presence of different phases of Ti with nitrogen (N), oxygen (O2), and carbon (C) elements was revealed by x-ray photoelectron spectroscopy characterization. Increase in the nitrogen pressure from 0.3 Pa to 0.6 Pa reduced the optical bandgap of the TiN thin film from 2.9 eV to 2.7 eV. Photoluminescence study showed that TiN thin film deposited at N2 partial pressure of 0.3 Pa exhibited three shoulder peaks at 330 nm, 335 nm, and 340 nm, which disappeared when the sample was deposited with N2 partial pressure of 0.6 Pa. Increase in the nitrogen content decreased the electrical resistivity of the TiN thin film from 3200 μΩ cm to 1800 μΩ cm. Atomic force microscopy studies of the TiN thin films deposited with N2 partial pressure of 0.6 Pa showed a uniform surface pattern associated with accumulation of fine grains. The results and advantages of this method of preparing TiN thin films are also reported.

  9. Preparation and characterization of baru (Dipteryx alata Vog) nut protein isolate and comparison of its physico-chemical properties with commercial animal and plant protein isolates.

    Science.gov (United States)

    Nunes, Ângela A; Favaro, Simone P; Miranda, Cesar H B; Neves, Valdir A

    2017-01-01

    The Brazilian leguminous tree locally known in the Cerrado Biome as baru (Dipteryx alata Vog), provides a healthy edible oil source. The proteinaceous cake remaining after oil extraction could be transformed into new products to foodstuff development, such as protein concentrates and isolates, adding value to the production chain. In this study, it is described the preparation and characterization of baru nut protein isolate (BPI) from deffated baru flour, and measurements of its functional, nutritional, and thermal properties, in comparison to the more common vegetable (soybeans) and animal (casein and albumin) protein sources of the food industry. BPI presented higher protein content than soybean, casein and albumin commercial protein isolates, despite losses of albumins and low molecular weight globulins during the isolation procedure. Thermodynamics studies suggested that BPI has a well-conserved protein arrangement and lower thermostability than the other protein sources. BPI showed high in vitro digestibility and suitable and desirable functional properties such as water and oil absorption capacity, emulsifying activity, and foam formation and stability at mild and neutral pH. BPI could be used either as a substitute ingredient in oily food formulations or in the development of new products of its own. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  10. In vitro Starch Hydrolysis Rate, Physico-chemical Properties and Sensory Evaluation of Butter Cake Prepared Using Resistant Starch Type III Substituted for Wheat Flour.

    Science.gov (United States)

    Pongjanta, J; Utaipattanaceep, A; Naivikul, O; Piyachomkwan, K

    2008-09-01

    Resistant starch type III (RS III) derived from enzymatically debranched high amylose rice starch was prepared and used to make butter cake at different levels (0, 5, 10, 15 and 20%) in place of wheat flour. Physico-chemical properties, sensory evaluation, and in vitro starch hydrolysis rate of the developed butter cake were investigated. This study showed that the content of resistant starch in butter cake increased significantly (Pcake with RS III replacement had a significantly lower in vitro starch hydrolysis rate compared to the control cake (0% RS III). The rates of starch hydrolysis from 0 to 180 min digestion time for 0, 5, 10 15, and 20% RS III in place of wheat flour in butter cakes were 3.70 to 67.65%, 2.97 to 64.86%, 2.86 to 59.99%, 2.79 to 55.96 and 2.78 to 53.04% respectively. The physico-chemical properties of 5 to 10% RS III substituted with wheat flour in the butter cake were not significantly different from the control cake and were moderately accepted by panellists in the sensory evaluation test.

  11. Characterization of CuInS2 thin films prepared by chemical bath deposition and their implementation in a solar cell

    International Nuclear Information System (INIS)

    Lugo, S.; López, I.; Peña, Y.; Calixto, M.; Hernández, T.; Messina, S.

    2014-01-01

    CuInS 2 thin films were formed by the sequential deposition of In 2 S 3 –CuS layers on glass substrates, by chemical bath deposition technique, and heating these multilayer 1 h at 350 °C and 400 mPa. The morphology and thickness of the CuInS 2 thin films were analysed by scanning electron microscopy, showing particles with elongated shape and length about 40 nm, and thickness of 267 and 348 nm for samples from 15 and 24 h of deposition time in the chemical bath of In 2 S 3 , respectively. The energy band gap values of the films were around 1.4 eV, whereas the electrical conductivity showed values from 64.91 to 4.11 × 10 −3 Ω −1 cm −1 for the samples of 15 and 24 h of In 2 S 3 deposition bath, respectively. The obtained CuInS 2 films showed appropriate values for their application as an absorbing layer in photovoltaic structures of the type: glass/SnO 2 :F/CdS/Sb 2 S 3 /CuInS 2 /PbS/C/Ag. The whole structure was obtained through chemical bath deposition technique. The solar cell corresponding to 15 h of In 2 S 3 deposition duration bath showed energy-conversion efficiency (η) of 0.53% with open circuit voltage (V oc ) of 530 mV, short circuit current density (J sc ) of 2.43 mA cm −2 , and fill factor (FF) of 0.41. In the case of the structure with 24 h of deposition of In 2 S 3 bath, η = 0.43% was measured with the following parameters: V oc = 330 mV, J sc = 4.78 mA cm −2 and FF = 0.27. - Highlights: • CuInS 2 films were formed by chemical bath deposition followed by a heat treatment. • Prepared CuInS 2 thin films can work as an effective absorbing layer in a solar cell. • A complete solar cell structure was made by a chemical bath deposition method

  12. Characterization of CuInS{sub 2} thin films prepared by chemical bath deposition and their implementation in a solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Lugo, S.; López, I. [Universidad Autónoma de Nuevo León, UANL, Facultad de Ciencias Químicas, Laboratorio de Materiales I, Av. Universidad, Cd. Universitaria 66451, San Nicolás de los Garza, Nuevo León, México (Mexico); Peña, Y., E-mail: yolapm@gmail.com [Universidad Autónoma de Nuevo León, UANL, Facultad de Ciencias Químicas, Laboratorio de Materiales I, Av. Universidad, Cd. Universitaria 66451, San Nicolás de los Garza, Nuevo León, México (Mexico); Calixto, M. [Instituto de Energías Renovables, Universidad Nacional Autónoma de México, C.P. 62580, Temixco, Morelos, México (Mexico); Hernández, T. [Universidad Autónoma de Nuevo León, UANL, Facultad de Ciencias Químicas, Laboratorio de Materiales I, Av. Universidad, Cd. Universitaria 66451, San Nicolás de los Garza, Nuevo León, México (Mexico); Messina, S. [Universidad Autónoma de Nayarit, Ciudad de la Cultura “Amado Nervo”, S/N C.P. 63155, Tepic, Nayarit, México (Mexico); and others

    2014-10-31

    CuInS{sub 2} thin films were formed by the sequential deposition of In{sub 2}S{sub 3}–CuS layers on glass substrates, by chemical bath deposition technique, and heating these multilayer 1 h at 350 °C and 400 mPa. The morphology and thickness of the CuInS{sub 2} thin films were analysed by scanning electron microscopy, showing particles with elongated shape and length about 40 nm, and thickness of 267 and 348 nm for samples from 15 and 24 h of deposition time in the chemical bath of In{sub 2}S{sub 3}, respectively. The energy band gap values of the films were around 1.4 eV, whereas the electrical conductivity showed values from 64.91 to 4.11 × 10{sup −3} Ω{sup −1} cm{sup −1} for the samples of 15 and 24 h of In{sub 2}S{sub 3} deposition bath, respectively. The obtained CuInS{sub 2} films showed appropriate values for their application as an absorbing layer in photovoltaic structures of the type: glass/SnO{sub 2}:F/CdS/Sb{sub 2}S{sub 3}/CuInS{sub 2}/PbS/C/Ag. The whole structure was obtained through chemical bath deposition technique. The solar cell corresponding to 15 h of In{sub 2}S{sub 3} deposition duration bath showed energy-conversion efficiency (η) of 0.53% with open circuit voltage (V{sub oc}) of 530 mV, short circuit current density (J{sub sc}) of 2.43 mA cm{sup −2}, and fill factor (FF) of 0.41. In the case of the structure with 24 h of deposition of In{sub 2}S{sub 3} bath, η = 0.43% was measured with the following parameters: V{sub oc} = 330 mV, J{sub sc} = 4.78 mA cm{sup −2} and FF = 0.27. - Highlights: • CuInS{sub 2} films were formed by chemical bath deposition followed by a heat treatment. • Prepared CuInS{sub 2} thin films can work as an effective absorbing layer in a solar cell. • A complete solar cell structure was made by a chemical bath deposition method.

  13. TiO{sub 2} based photo-catalysts prepared by chemical vapor infiltration (CVI) on micro-fibrous substrates; Photocatalyseurs a base de TiO{sub 2} prepares par infiltration chimique en phase vapeur (CVI) sur supports microfibreux

    Energy Technology Data Exchange (ETDEWEB)

    Sarantopoulos, Ch

    2007-10-15

    This thesis deals with micro-fibrous glass substrates functionalized with TiO{sub 2}. The oxide is deposited as a thin film onto the micro fibres by chemical vapour infiltration (CVI), yielding a photo-catalytic material usable for cleaning polluted air. We studied the relation between the structure of the material and its photo-catalytic efficiency. TiO{sub 2} thin films were prepared at low pressure, in a hot-wall CVD reactor, using Ti(O-iPr){sub 4} as a precursor. They were characterized by XRD, SEM, EDX, XPS and BET, and by recording the kinetics of decomposition of varied pollutants in solution (orange G, malic acid, imazapyr) and in air (toluene). The conditions favoring the growth of porous films through a columnar growth mode were established by MOCVD-depositing TiO{sub 2} thin films on flat substrates. The subsequent works with micro fibrous thick substrates showed the uniformity of infiltration to be the main factor governing the photo-catalytic efficiency. Operating parameters that optimize infiltration do not yield columnar growth mode. A compromise is necessary. Our photo-catalysts are showing high efficiency comparable, if not higher, to those actually commercialized. These promising results are opening real perspectives for the proposed process. (author)

  14. Microstructure, in vitro corrosion and cytotoxicity of Ca-P coatings on ZK60 magnesium alloy prepared by simple chemical conversion and heat treatment.

    Science.gov (United States)

    Li, Kaikai; Wang, Bing; Yan, Biao; Lu, Wei

    2013-09-01

    Magnesium alloys are potential biodegradable materials for biomedical application. But their poor corrosion resistance may result in premature failure of implants. In this study, to solve this problem, Ca-P coatings were prepared on ZK60 magnesium alloy by a simple chemical conversion process and heat treatment. Surface characterization showed that a flake-like Dicalcium phosphate dihydrate (DCPD) (CaHPO₄·2H₂O) coating was formed on ZK60 alloy by the chemical conversion process. DCPD transformed into Dicalcium phosphate anhydrous (DCPa) (CaHPO₄) and Ca₂P₂O₇ after heat treatment. Results of potentiodynamic polarization showed the corrosion potential of ZK60 was increased from -1666 mV to -1566 mV with DCPD coating, while -1515 mV was obtained after heat treatment. The corrosion current density of ZK60 was measured to be reduced from 35 µA/cm² to 3.5 µA/cm² with DCPD coating, while a further reduction to 1 µA/cm² was observed after heat treatment. This indicated that the coatings improved the substrate corrosion resistance significantly, and apparently, the heat-treated coating had a higher corrosion resistance. Immersion test demonstrated that both the coatings could provide protection for the substrate and the heat-treated coating could induce deposition of bone-like apatite. Cytotoxicity evaluation revealed that none of the samples induced toxicity to L-929 cells after 1- and 3-day culture. The cytocompatibility of ZK60 was improved by the coatings, with the following sequence: uncoated ZK60 < DCPD-coated ZK60 < heat-treated coating.

  15. Preparation of nanocrystalline Ni doped ZnS thin films by ammonia-free chemical bath deposition method and optical properties

    Energy Technology Data Exchange (ETDEWEB)

    Sahraei, Reza, E-mail: r.sahraei@ilam.ac.ir; Darafarin, Soraya

    2014-05-01

    Nanocrystalline Ni doped ZnS thin films were deposited on quartz, silicon, and glass substrates using chemical bath deposition method in a weak acidic solution containing ethylenediamine tetra acetic acid disodium salt (Na{sub 2}EDTA) as a complexing agent for zinc ions and thioacetamide (TAA) as a sulfide source at 80 °C. The films were characterized by energy-dispersive X-ray spectrometer (EDX), inductively coupled plasma atomic emission spectroscopy (ICP-AES), Fourier transform-infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet–visible spectrophotometry, and photoluminescence (PL) spectroscopy. UV–vis transmission data showed that the films were transparent in the visible region. The X-ray diffraction analysis showed a cubic zinc blend structure. FE-SEM revealed a homogeneous morphology and dense nanostructures. The PL spectra of the ZnS:Ni films showed two characteristic bands, one broad band centered at 430 and another narrow band at 523 nm. Furthermore, concentration quenching effect on the photoluminescence intensity has been observed. - Highlights: • Nanocrystalline ZnS:Ni thin films were prepared by the chemical bath deposition method. • The size of ZnS:Ni nanocrystals was less than 10 nm showing quantum size effect. • SEM images demonstrated a dense and uniform surface that was free of pinholes. • The deposited films were highly transparent (>70%) in the visible region. • The PL spectra of ZnS:Ni thin films showed two emission peaks at 430 and 523 nm.

  16. Solution preparation

    International Nuclear Information System (INIS)

    Seitz, M.G.

    1982-01-01

    Reviewed in this statement are methods of preparing solutions to be used in laboratory experiments to examine technical issues related to the safe disposal of nuclear waste from power generation. Each approach currently used to prepare solutions has advantages and any one approach may be preferred over the others in particular situations, depending upon the goals of the experimental program. These advantages are highlighted herein for three approaches to solution preparation that are currently used most in studies of nuclear waste disposal. Discussion of the disadvantages of each approach is presented to help a user select a preparation method for his particular studies. Also presented in this statement are general observations regarding solution preparation. These observations are used as examples of the types of concerns that need to be addressed regarding solution preparation. As shown by these examples, prior to experimentation or chemical analyses, laboratory techniques based on scientific knowledge of solutions can be applied to solutions, often resulting in great improvement in the usefulness of results

  17. Structure and electrical properties of (La, Zn) Co-doped BiFeO3 thin films prepared by using chemical solution deposition

    Science.gov (United States)

    Kim, Y. J.; Kim, H. J.; Kim, J. W.; Raghavan, C. M.; Kim, S. S.

    2012-08-01

    We prepared pure BiFeO3 (BFO) and (Bi0.9La0.1)(Fe0.975Zn0.025)O3- δ (BLFZO) thin films on Pt(111)/Ti/SiO2/Si(100) substrates by using a chemical solution deposition method. Improved electrical properties were observed in the co-doped BLFZO thin film. The leakage current density of the BLFZO thin film was four orders of magnitude lower than that of the pure BFO, 4.17 × 10-7 A/cm2 at 100 kV/cm. The remnant polarization (2 P r ) and the coercive electric field (2 E c ) of the BLFZO thin film were 97 µC/cm2 and 903 kV/cm at an applied electric field of 972 kV/cm and at a frequency of 1 kHz, and the values decreased with increasing measurement frequency to 63 µC/cm2 and 679 kV/cm at 10 kHz, respectively. Also, after 1.44 × 1010 cycles, a better fatigue endurance was observed in the BLFZO thin film, which was 90% of its initial value. We also confirmed that the remnant polarization (2 P r ) and the coercive electric field (2 E c ) were fairly saturated above a measurement frequency of 15 kHz for the BLFZO thin film.

  18. Enhancement of the electrical properties of (Eu,Zn) co-doped BiFeO3 thin films prepared by using chemical solution deposition

    Science.gov (United States)

    Kim, Youn-Jang; Kim, Jin Won; Kim, Hae Jin; Kim, Sang Su

    2013-04-01

    We prepared pure BiFeO3 (BFO) and (Bi0.9Eu0.1)(Fe0.975Zn0.025)O3-δ (BEFZO) thin films on Pt(111)/Ti/SiO2/Si(100) substrates by using a chemical solution deposition method. Improved electrical properties were observed in the co-doped BEFZO thin film. The leakage current density of the BEFZO thin film was three orders of magnitude lower than that of the pure BFO, 3.93 × 10-6 A/cm2 at 100 kV/cm. The remnant polarization (2 P r ) and the coercive electric field (2 E c ) of the BEFZO thin film were 42 µC/cm2 and 898 kV/cm at an applied electric field of 1000 kV/cm and at a frequency of 1 kHz and the values decreased with increasing measurement frequency to 18 µC/cm2 and 866 kV/cm at 10 kHz, respectively. Also, the fatigue endurances were evaluated at peak voltages of 8-10 V after 1.44 × 1010 cycles in the BEFZO thin films and were 70 ˜ 90% of the initial values. We also confirmed that the 2 P r was fairly saturated at measurement frequency about 30 kHz for the BEFZO thin film.

  19. ZnO nanorod arrays prepared by chemical bath deposition combined with rapid thermal annealing: structural, photoluminescence and field emission characteristics

    International Nuclear Information System (INIS)

    Chen, Hung-Wei; He, Hsin-Min; Lee, Yi-Mu; Yang, Hsi-Wen

    2016-01-01

    ZnO nanorod arrays were prepared by low temperature chemical bath deposition (CBD) combined with rapid thermal annealing (RTA) under different ambient conditions. The structure and morphology of the synthesized ZnO have been characterized by field-emission scanning electron microscopy (FESEM) and x-ray diffraction (XRD). The obtained ZnO samples are highly crystalline with a hexagonal wurtzite phase and also display well-aligned array structure. A pronounced effect on increased nanorod length was found for the RTA-treated ZnO as compared to the as-grown ZnO. Analysis of XRD indicates that the (0 0 2) feature peak of the as-grown ZnO was shifted towards a lower angle as compared to the peaks of RTA-treated ZnO samples due to the reduction of tensile strain along the c-axis by RTA. Photoluminescence (PL) studies reveal that the ZnO nanorod arrays receiving RTA in an O 2 environment have the sharpest UV emission band and greatest intensity ratio of near band-edge emission (NBE) to deep level emission (DLE). Additionally, the effects of RTA on the field emission properties were evaluated. The results demonstrate that RTA an O 2 environment can lower the turn-on field and improve the field enhancement factor. The stability of the field emission current was also tested for 4 h. (paper)

  20. Thermal expansion coefficient and thermomechanical properties of SiN(x) thin films prepared by plasma-enhanced chemical vapor deposition.

    Science.gov (United States)

    Tien, Chuen-Lin; Lin, Tsai-Wei

    2012-10-20

    We present a new method based on fast Fourier transform (FFT) for evaluating the thermal expansion coefficient and thermomechanical properties of thin films. The silicon nitride thin films deposited on Corning glass and Si wafers were prepared by plasma-enhanced chemical vapor deposition in this study. The anisotropic residual stress and thermomechanical properties of silicon nitride thin films were studied. Residual stresses in thin films were measured by a modified Michelson interferometer associated with the FFT method under different heating temperatures. We found that the average residual-stress value increases when the temperature increases from room temperature to 100°C. Increased substrate temperature causes the residual stress in SiN(x) film deposited on Si wafers to be more compressive, but the residual stress in SiN(x) film on Corning glass becomes more tensile. The residual-stress versus substrate-temperature relation is a linear correlation after heating. A double substrate technique is used to determine the thermal expansion coefficients of the thin films. The experimental results show that the thermal expansion coefficient of the silicon nitride thin films is 3.27×10(-6)°C(-1). The biaxial modulus is 1125 GPa for SiN(x) film.

  1. Annealing effect on the photoluminescence properties of ZnO nanorod array prepared by a PLD-assistant wet chemical method

    International Nuclear Information System (INIS)

    Wei Sufeng; Lian Jianshe; Wu Hua

    2010-01-01

    Well-aligned ZnO nanorod arrays were synthesized by a wet chemical method on the glass substrate with ZnO thin film as seed layer prepared by pulsed laser deposition. The effect of annealing temperature on the luminescence characteristics was investigated. As the annealing temperature increased, the photoluminescence properties show a general enhancing tendency. The nanorod array with high ultraviolet emission and negligible visible light emission (designated by the photoluminescence intensity ratio of ultraviolet to visible emission of 66.4) is obtained by annealing the sample at 700 deg. C for 1 h. Based on the results of X-ray photoelectron spectroscopy and photoluminescence spectra, the mechanisms of visible emission were discussed. - Research Highlights: → ZnO nanorod array with good crystallography, low defects concentration and good optical property was obtained after annealed at 700 deg. C for 1 h. → The transition from the conduction band to the O i level may be responsible for the yellow-green emission. → The yellow emission may originate from the presence of Zn(OH) 2 on the surface or the band transition from conduction band to V o Zn i level. → The transition from the Zn i level to the level should produce an orange emission or an orange-red emission.

  2. Thermal shock behavior of W-0.5 wt% Y{sub 2}O{sub 3} alloy prepared via a novel chemical method

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Mei-Ling [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Luo, Lai-Ma, E-mail: luolaima@126.com [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); National-Local Joint Engineering Research Centre of Nonferrous Metals and Processing Technology, Hefei 230009 (China); Lin, Jing-Shan [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Zan, Xiang; Zhu, Xiao-Yong [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); National-Local Joint Engineering Research Centre of Nonferrous Metals and Processing Technology, Hefei 230009 (China); Luo, Guang-Nan [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Wu, Yu-Cheng, E-mail: ycwu@hfut.edu.cn [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); National-Local Joint Engineering Research Centre of Nonferrous Metals and Processing Technology, Hefei 230009 (China)

    2016-10-15

    A wet-chemical method combined with spark plasma sintering was used to prepare W-0.5 wt% Y{sub 2}O{sub 3} alloy. The W-0.5 wt% Y{sub 2}O{sub 3} precursor was reduced at 800 °C for 4 h under different hydrogen flow rates of 300, 400, 500, 600, and 700 ml/min. The reduced powder was analyzed by X-ray diffraction (XRD), laser particle size analyzer (LPSA), and scanning electron microscopy (SEM). An optimized process for reducing precursor was discussed. After sintering, the specimens were exposed to different laser beam irradiation energies (90, 120, 150, and 180 W) to simulate loads as expected for edge localized modes (ELMs). Top surface and cross-sectional morphology were observed by SEM, and the changes in hardness were evaluated. The changes in microstructural properties (i.e., Y{sub 2}O{sub 3}-particle distribution, crack propagation direction, depth of thermal shock effect, and grain size of the recrystallization region) after thermal shock were investigated.

  3. Removal of Zn(II) and Hg(II) from aqueous solution on a carbonaceous sorbent chemically prepared from rice husk

    International Nuclear Information System (INIS)

    El-Shafey, E.I.

    2010-01-01

    A carbonaceous sorbent was prepared from rice husk via sulfuric acid treatment. Sorption of Zn(II) and Hg(II) from aqueous solution was studied varying time, pH, metal concentration, temperature and sorbent status (wet and dry). Zn(II) sorption was found fast reaching equilibrium within ∼2 h while Hg(II) sorption was slow reaching equilibrium within ∼120 h with better performance for the wet sorbent than for the dry. Kinetics data for both metals were found to follow pseudo-second order model. Sorption rate of both metals was enhanced with temperature rise. Activation energy, E a , for Zn(II) sorption, was ∼13.0 kJ/mol indicating a diffusion-controlled process ion exchange process, however, for Hg(II) sorption, E a was ∼54 kJ/mol indicating a chemically controlled process. Sorption of both metals was low at low pH and increased with pH increase. Sorption was much higher for Hg(II) than for Zn(II) with higher uptake for both metals by rising the temperature. Hg(II) was reduced to Hg(I) on the sorbent surface. This was confirmed from the identification of Hg 2 Cl 2 deposits on the sorbent surface by scanning electron microscopy and X-ray diffraction. However, no redox processes were observed in Zn(II) sorption. Sorption mechanism is discussed.

  4. Chemical composition, antioxidative and anti-inflammatory activity of extracts prepared from aerial parts of Oenothera biennis L. and Oenothera paradoxa Hudziok obtained after seeds cultivation.

    Science.gov (United States)

    Granica, Sebastian; Czerwińska, Monika E; Piwowarski, Jakub P; Ziaja, Maria; Kiss, Anna K

    2013-01-30

    In the present study we investigated the chemical composition of extracts prepared from aerial parts of Oenothera paradoxa Hudziok and Oenothera biennis L. and their antioxidative and anti-inflammatory activities. Ultra high pressure liquid chromatography (UHPLC)-DAD-MS/MS studies showed that both extracts contain a wide variety of polyphenols (39 identified constituents) among which macrocyclic ellagitannin turned out to be the main constituent. During the in vitro studies, using noncellular models, both extracts scavenged reactive oxygen species (ROS) in a concentration-dependent manner, and the lowest SC(50) values were obtained for O(2)(-) and H(2)O(2). Both extracts inhibited ROS production by stimulated human neutrophils. The stronger activity in the case of formyl-met-leu-phenylalanine stimulation suggests that both extracts may act through the receptor-dependent pathway. O. paradoxa extract and O. biennis extract exhibited anti-inflammatory activity by the inhibition of hyaluronidase and lipoxygenase in a concentration-dependent manner. The stronger activity of O.biennis extract toward lipoxygenase may be explained by its higher oenothein B content.

  5. Thermal shock behavior of W-0.5 wt% Y_2O_3 alloy prepared via a novel chemical method

    International Nuclear Information System (INIS)

    Zhao, Mei-Ling; Luo, Lai-Ma; Lin, Jing-Shan; Zan, Xiang; Zhu, Xiao-Yong; Luo, Guang-Nan; Wu, Yu-Cheng

    2016-01-01

    A wet-chemical method combined with spark plasma sintering was used to prepare W-0.5 wt% Y_2O_3 alloy. The W-0.5 wt% Y_2O_3 precursor was reduced at 800 °C for 4 h under different hydrogen flow rates of 300, 400, 500, 600, and 700 ml/min. The reduced powder was analyzed by X-ray diffraction (XRD), laser particle size analyzer (LPSA), and scanning electron microscopy (SEM). An optimized process for reducing precursor was discussed. After sintering, the specimens were exposed to different laser beam irradiation energies (90, 120, 150, and 180 W) to simulate loads as expected for edge localized modes (ELMs). Top surface and cross-sectional morphology were observed by SEM, and the changes in hardness were evaluated. The changes in microstructural properties (i.e., Y_2O_3-particle distribution, crack propagation direction, depth of thermal shock effect, and grain size of the recrystallization region) after thermal shock were investigated.

  6. Effects of annealing schedule on orientation of Bi3.2Nd0.8Ti3O12 ferroelectric film prepared by chemical solution deposition process

    International Nuclear Information System (INIS)

    He, H.Y.; Huang, J.F.; Cao, L.Y.; Wang, L.S.

    2006-01-01

    Fatigue-free Bi 3.2 Nd 0.8 Ti 3 O 12 ferroelectric thin films were successfully prepared on p-Si(1 1 1) substrate using chemical solution deposition process. The orientation and formation of thin film under different annealing schedules were studied. XRD analysis indicated that (2 0 0)-oriented films with degree of orientation of I (200) /I (117) = 2.097 and 0.466 were obtained by preannealing for 10 min at 400 deg. C followed by rapid thermal annealing for 3, 10 and 20 min at 700 deg. C, respectively (0 0 8)-oriented films with degree of orientation of I (008) /I (117) = 1.706 were obtained by rapid thermal annealing for 3 min at 700 deg. C without preannealing, and (0 0 8)-oriented films with degree of orientation of I (008) /I (117) = 0.719 were obtained by preheating the film from room temperature at 20 deg. C/min followed by annealing for 10 min at 700 deg. C. The a-axis and c-axis orientation decreased as increase of annealing time due to effects of (1 1 1)-oriented substrate. AFM analysis further indicated that preannealing at 400 deg. C for 10 min followed by rapid thermal annealing for 3 min at 700 deg. C resulted in formation of platelike crystallite parallel to substrate surface, however rapid thermal annealing for 3 min at 700 deg. C without preannealing resulted in columnar crystallite perpendicular to substrate surface

  7. Ultra-high performance liquid chromatography coupled with quadrupole/time of flight mass spectrometry based chemical profiling approach for the holistic quality control of complex Kang-Jing formula preparations.

    Science.gov (United States)

    Yang, Xiao-Huan; Cheng, Xiao-Lan; Qin, Bing; Cai, Zhuo-Ya; Cai, Xiong; Liu, Shao; Wang, Qi; Qin, Yong

    2016-05-30

    The Kang-Jing (KJ) formula is a compound preparation made from 12 kinds of herbs. So far, four different methods (M1-M4) have been documented for KJ preparation, but the influence of preparation methods on the holistic quality of KJ have remained unknown. In this study, a strategy was proposed to investigate the influence of different preparation methods on the holistic quality of KJ using ultra-high performance liquid chromatography coupled with quadrupole/time of flight mass spectrometry (UHPLC-QTOF-MS/MS) based chemical profiling. A total of 101 compounds mainly belonging to flavonoids, tanshinones, monoterpene glycosides, triterpenoid saponins, alkaloids, phenolic acids and volatile oils, were identified. Among these compounds, glaucine was detected only in M3/M4 samples, while two dehydrocorydaline isomers merely detected in M2/M3/M4 samples. Tetrahydrocolumbamine, ethylic lithospermic acid, salvianolic acid E and rosmarimic acid were only detected in M1/M3/M4 samples. In the subsequent quantitative analysis, 12 major compounds were determined by UHPLC-MS/MS. The proposed method was validated with respect to linearity, accuracy, precision and recovery. It was found that the contents of marker compounds varied significantly in samples prepared by different methods. These results demonstrated that preparation method does significantly affect the holistic quality of KJ. UHPLC-QTOF-MS/MS based chemical profiling approach is efficient and reliable for comprehensive quality evaluation of KJ. Collectively, this study provide the chemical evidence for revealing the material basis of KJ, and establish a simple and accurate chemical profiling method for its quality control. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Equilibrium diagram of KPO{sub 3}-Y(PO{sub 3}){sub 3} system, chemical preparation and characterization of KY(PO{sub 3}){sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Jouini, Anis; Ferid, Mokhtar; Trabelsi-Ayadi, Malika

    2003-04-17

    Microdifferential thermal analysis ({mu}-DTA), X-ray diffraction (XRD) and infrared (IR) spectroscopy were used for the first time to investigate the liquidus and solidus relations in the KPO{sub 3}-Y(PO{sub 3}){sub 3} system. The only compound observed within the system was KY(PO{sub 3}){sub 4} melting incongruently at 1033 K. An eutectic appears at 13.5 mol% Y(PO{sub 3}){sub 3} at 935 K, the peritectic occurs at 1033 K and the phase transition for potassium polyphosphate KPO{sub 3} was observed at 725 K. Three monoclinic allotropic phases of the single crystals were obtained. KY(PO{sub 3}){sub 4} polyphosphate has the P2{sub 1} space group with lattice parameters: a=7.183(4) A, b=8.351(6) A, c=7.983(3) A, {beta}=91.75(3) deg. and Z=2 is isostructural with KNd(PO{sub 3}){sub 4}. The second allotropic form of KY(PO{sub 3}){sub 4} belongs to the P2{sub 1}/n space group with lattice parameters: a=10.835(3) A, b=9.003(2) A, c=10.314(1) A, {beta}=106.09(7) deg. and Z=4 and is isostructural with TlNd(PO{sub 3}){sub 4}. The IR absorption spectra of the two forms show a chain polyphosphates structure. The last modification of KYP{sub 4}O{sub 12} crystallizes in the C2/c space group with lattice parameters: a=7.825(3) A, b=12.537(4) A, c=10.584(2) A, {beta}=110.22(7) deg. and Z=4 is isostructural with RbNdP{sub 4}O{sub 12} and contains cyclic anions. The methods of chemical preparations, the determination of crystallographic data and IR spectra for these compounds are reported.

  9. Influence of boron concentration on growth characteristic and electro-catalytic performance of boron-doped diamond electrodes prepared by direct current plasma chemical vapor deposition

    International Nuclear Information System (INIS)

    Feng Yujie; Lv Jiangwei; Liu Junfeng; Gao Na; Peng Hongyan; Chen Yuqiang

    2011-01-01

    A series of boron-doped diamond (BDD) electrodes were prepared by direct current plasma chemical vapor deposition (DC-PCVD) with different compositions of CH 4 /H 2 /B(OCH 3 ) 3 gas mixture. A maximum growth rate of 0.65 mg cm -2 h -1 was obtained with CH 4 /H 2 /B(OCH 3 ) 3 radio of 4/190/10 and this growth condition was also a turning point for discharge plasma stability which arose from the addition of B(OCH 3 ) 3 that changed electron energy distribution and influenced the plasma reaction. The surface coating structure and electro-catalytic performance of the BDD electrodes were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, Hall test, and electrochemical measurement and electro-catalytic oxidation in phenol solution. It is suggested that the boron doping level and the thermal stress in the films are the main factors affecting the electro-catalytic characteristics of the electrodes. Low boron doping level with CH 4 /H 2 /B(OCH 3 ) 3 ratio of 4/199/1 decreased the films electrical conductivity and its electro-catalytic activity. When the carrier concentration in the films reached around 10 20 cm -3 with CH 4 /H 2 /B(OCH 3 ) 3 ratio over a range of 4/195/5-4/185/15, the thermal stress in the films was the key reason that influenced the electro-catalytic activity of the electrodes for its effect on diamond lattice expansion. Therefore, the BDD electrode with modest CH 4 /H 2 /B(OCH 3 ) 3 ratio of 4/190/10 possessed the best phenol removal efficiency.

  10. Equilibrium diagram of KPO3-Y(PO3)3 system, chemical preparation and characterization of KY(PO3)4

    International Nuclear Information System (INIS)

    Jouini, Anis; Ferid, Mokhtar; Trabelsi-Ayadi, Malika

    2003-01-01

    Microdifferential thermal analysis (μ-DTA), X-ray diffraction (XRD) and infrared (IR) spectroscopy were used for the first time to investigate the liquidus and solidus relations in the KPO 3 -Y(PO 3 ) 3 system. The only compound observed within the system was KY(PO 3 ) 4 melting incongruently at 1033 K. An eutectic appears at 13.5 mol% Y(PO 3 ) 3 at 935 K, the peritectic occurs at 1033 K and the phase transition for potassium polyphosphate KPO 3 was observed at 725 K. Three monoclinic allotropic phases of the single crystals were obtained. KY(PO 3 ) 4 polyphosphate has the P2 1 space group with lattice parameters: a=7.183(4) A, b=8.351(6) A, c=7.983(3) A, β=91.75(3) deg. and Z=2 is isostructural with KNd(PO 3 ) 4 . The second allotropic form of KY(PO 3 ) 4 belongs to the P2 1 /n space group with lattice parameters: a=10.835(3) A, b=9.003(2) A, c=10.314(1) A, β=106.09(7) deg. and Z=4 and is isostructural with TlNd(PO 3 ) 4 . The IR absorption spectra of the two forms show a chain polyphosphates structure. The last modification of KYP 4 O 12 crystallizes in the C2/c space group with lattice parameters: a=7.825(3) A, b=12.537(4) A, c=10.584(2) A, β=110.22(7) deg. and Z=4 is isostructural with RbNdP 4 O 12 and contains cyclic anions. The methods of chemical preparations, the determination of crystallographic data and IR spectra for these compounds are reported

  11. Sol-gel process preparation and evaluation of the analytical performances of an hydrazine specific chemical sensor; Preparation par procede sol-gel et evaluation des performances analytiques d`un capteur chimique specifique de l`hydrazine

    Energy Technology Data Exchange (ETDEWEB)

    Gojon, C

    1996-12-01

    The realisation of optical fibers active chemical collector to analyze hydrazine in line, in the spent fuel reprocessing process is the subject of this work. The p.dimethyl-amino-benzaldehyde has been chosen as reagent for its chemical and optical properties. 186 refs.

  12. Detection of Anisotropic Hyperfine Components of Chemically Prepared Carotenoid Radical Cations:1D and 2D ESEEM and Pulsed ENDOR Study

    International Nuclear Information System (INIS)

    Konovalova, Tatyana A.; Dikanov, Sergei A.; Bowman, Michael K.; Kispert, Lowell D.

    2001-01-01

    Canthaxanthin and 8'-apo-B-caroten-8'-al radical cations chemically prepared on activated silica-alumina and in CH2CI2 solution containing A1C13 were studied by pulsed EPR and ENDOR spectroscopies. Both the 1D three-pulse ESEEM and the 2D HYSCORE spectra of the carotenoid-A1C13 mixtures exhibited the 27 A1 nuclei peak at 3.75 MHz. This indicates electron-transfer interactions between carotenoids and A1III ions resulting in the formation and stabilization of carotenoid radical cations. Davies ENDOR measurements of the canthaxanthin radical cation on silica-alumina determined the hyperfine couplings of B protons belonging to three different methyl groups with ahI=2.6 MHz, aH2=8.6MHz, and ah3 ca. 13 MHz. The principal components of the proton hyperfine tensors were obtained from HYSCORE spectra in A1C13 solutions and on the solid support. Identification of the protons was made on the basis of isotropic hyperfine couplings determined by RHF-INDO/SP molecular orbital calculations. In frozen A1C13 solution, the C(7, 7')Ha and C(14, 14')-Ha a protons were observed for Canthaxanthin and the C(8 or 14')-Ha, C(15')-Ha were observed for 8'-apo-B-caroten-8'-al. On the silica-alumina support, the C(10, 10')-Ha, C(11, 11')-Ha, and C(15,15')-Ha a protons were measured for Canthaxanthin and the C(12)-Ha and C(15')-Ha were measured for 8' apo-B-caroten-8'-al. Some protons with large isotropic couplings (> 10 MHz) determined from HYSCORE analysis could be assigned to B protons, but the principal components of their hyperfine tensors are much more anisotropic than those reported previously for B protons. We suggest that cis/trans isomerization of carotenoids on silica-alumina results in stabilization of di-cis isomers with large isotropic couplings for some a protons which are comparable to those of B protons

  13. Preparation of an antitumor and antivirus agent: chemical modification of α-MMC and MAP30 from Momordica Charantia L. with covalent conjugation of polyethyelene glycol.

    Science.gov (United States)

    Meng, Yao; Liu, Shuangfeng; Li, Juan; Meng, Yanfa; Zhao, Xiaojun

    2012-01-01

    Alpha-momorcharin (α-MMC) and momordica anti-HIV protein (MAP30) derived from Momordica charantia L. have been confirmed to possess antitumor and antivirus activities due to their RNA-N-glycosidase activity. However, strong immunogenicity and short plasma half-life limit their clinical application. To solve this problem, the two proteins were modified with (mPEG)(2)-Lys-NHS (20 kDa). In this article, a novel purification strategy for the two main type I ribosome-inactivating proteins (RIPs), α-MMC and MAP30, was successfully developed for laboratory-scale preparation. Using this dramatic method, 200 mg of α-MMC and about 120 mg of MAP30 was obtained in only one purification process from 200 g of Momordica charantia seeds. The homogeneity and some other properties of the two proteins were assessed by gradient SDS-PAGE, electrospray ionization quadruple mass spectrometry, and N-terminal sequence analysis as well as Western blot. Two polyethylene glycol (PEG)ylated proteins were synthesized and purified. Homogeneous mono-, di-, or tri-PEGylated proteins were characterized by matrix-assisted laser desorption ionization-time of flight mass spectrometry. The analysis of antitumor and antivirus activities indicated that the serial PEGylated RIPs preserved moderate activities on JAR choriocarcinoma cells and herpes simplex virus-1. Furthermore, both PEGylated proteins showed about 60%-70% antitumor and antivirus activities, and at the same time decreased 50%-70% immunogenicity when compared with their unmodified counterparts. α-MMC and MAP30 obtained from this novel purification strategy can meet the requirement of a large amount of samples for research. Their chemical modification can solve the problem of strong immunogenicity and meanwhile preserve moderate activities. All these findings suggest the potential application of PEGylated α-MMC and PEGylated MAP30 as antitumor and antivirus agents. According to these results, PEGylated RIPs can be constructed with

  14. Preparation of an antitumor and antivirus agent: chemical modification of α-MMC and MAP30 from Momordica Charantia L. with covalent conjugation of polyethyelene glycol

    Directory of Open Access Journals (Sweden)

    Meng Y

    2012-06-01

    Full Text Available Yao Meng,1,2 Shuangfeng Liu,1 Juan Li,3 Yanfa Meng,3 Xiaojun Zhao2,41School of Medical Laboratory Science, Chengdu Medical College, Chengdu, China; 2West China Hospital Laboratory of Nanomedicine and Institute for Nanobiomedical Technology and Membrane Biology, Sichuan University, Chengdu, China; 3Key Laboratory of Bio-resources and Eco-environment Ministry of Education/Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province, College of Life Science, Sichuan University, Chengdu, China; 4Center for Biomedical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USABackground: Alpha-momorcharin (α-MMC and momordica anti-HIV protein (MAP30 derived from Momordica charantia L. have been confirmed to possess antitumor and antivirus activities due to their RNA-N-glycosidase activity. However, strong immunogenicity and short plasma half-life limit their clinical application. To solve this problem, the two proteins were modified with (mPEG2-Lys-NHS (20 kDa.Methodology/principal findings: In this article, a novel purification strategy for the two main type I ribosome-inactivating proteins (RIPs, α-MMC and MAP30, was successfully developed for laboratory-scale preparation. Using this dramatic method, 200 mg of α-MMC and about 120 mg of MAP30 was obtained in only one purification process from 200 g of Momordica charantia seeds. The homogeneity and some other properties of the two proteins were assessed by gradient SDS-PAGE, electrospray ionization quadruple mass spectrometry, and N-terminal sequence analysis as well as Western blot. Two polyethylene glycol (PEGylated proteins were synthesized and purified. Homogeneous mono-, di-, or tri-PEGylated proteins were characterized by matrix-assisted laser desorption ionization-time of flight mass spectrometry. The analysis of antitumor and antivirus activities indicated that the serial PEGylated RIPs preserved moderate activities on JAR choriocarcinoma cells and herpes simplex

  15. 99mTc bone scanning agents preparation and chemical analysis of Tc(Sn)pyrophosphate, Tc(Sn)MDP and Tc(Sn)HMDP

    International Nuclear Information System (INIS)

    Kroesbergen, J.

    1986-01-01

    This thesis describes a comparison of the preparation, composition and properties of three bone scanning agents: 99m Tc(Sn)pyrophosphate, 99m Tc(Sn)MDP and 99m Tc(Sn)HMDP. This study has been performed for two reasons: First to investigate the preparation and composition of the radiopharmaceuticals as a function of experimental conditions. Together with previously reported results for 99m Tc(Sn)EHDP, obtained in a similar way, this enables to use well-defined preparations of the bone scanning agents. Secondly to gain an insight in the mechanism in which the agents behave 'in vivo'. Because the 'in vivo' process is too complicated to study directly, it seemed more appropriate to perform 'in vitro' investigations as simplifications of the 'in vivo' situation. 304 refs.; 26 figs.; 31 tabs

  16. Effect of preparation methods of LiNi1-xCoxO2 cathode materials on their chemical structure and electrode performance

    International Nuclear Information System (INIS)

    Cho, J.; Kim, G.; Lim, H.S.

    1999-01-01

    The authors have studied effects of different starting materials on preparation of LiNi 1-x Co x O 2 cathode material for a Li-ion cell where x = 0.1, 0.2, and 0.3, and the electrochemical properties of resulting compounds from two different preparation methods. A preparation method (method B) which uses spherical powder of Ni 1-x Co x (OH) 2 as one of the starting material produced a much superior cathode material than the other method (method A) which uses Ni(OH) 2 and Co(OH) 2 . Method A produced compounds with relatively high degrees of cation mixing which reduces electrochemical utilization (discharge capacity), increases irreversible capacity, and reduces stability on cycling of the cathode material. Method B, in contrast, produced cathode material with a much reduced degree of cation-mixing, thus improving the electrochemical properties. The spherical particle of material prepared by method B has the additional advantage of improved packing density of the electrode with improved volumetric energy density. The ratio of c/a was increased and the electrochemical stability on cycling of the material was improved as the content of Co (value of x) is increased

  17. Preparation of YBa2Cu3O7-x superconducting solutions and films from alkoxide-based precursors using sol-gel method and investigation of their chemical reaction mechanisms

    International Nuclear Information System (INIS)

    Mutlu, Ibrahim Halil; Acun, Hediye; Celik, Erdal; Turkmen, Hasan

    2007-01-01

    In the development of coated superconductors sol-gel technique has been widely used as an effective processing method, especially in making long-length wires and tapes. However, one drawback associated with the deposition of YBa 2 Cu 3 O 7-x and Gd 2 O 3 buffer layer on Ni tape is the adhesion characteristic at interfaces YBCO-Gd 2 O 3 and Gd 2 O 3 -NiO and NiO-Ni substrate. In this paper, two strategies for adhesion enhancement of multilayered ceramic oxide coatings on Ni substrate were proposed: (1) formation of chemical bonds through surface condensation reactions, and development of ceramic networks through diffusion of alkoxide precursors. The current research has focused on the fabrication and adhesion of YBCO coatings on buffered Ni substrate using nine solutions prepared from Y, Ba and Cu alkoxides, solvent and chelating agent. Only two of YBCO solutions were successfully obtained while the rest of them were unsuccessful. Among these solutions we scrutinized chemical reaction mechanisms of a successful and an unsuccessful solution for comparison. How the chemical bonds and solubility were affected by the acids, base and solvents used in the solutions was demonstrated. It was shown that pH of the solution, homogeneity of the solution and gelation, steric affect of the chemicals in sol-gel solutions are significant issues to obtain high quality superconducting YBCO thin films. In addition, X-ray diffraction (XRD) was used to analyze phase structure of YBCO and compare results of chemical reactions obtained by a chemdraw programme. Scanning electron microscope (SEM) studies was carried out to examine microstructures of YBCO films produced from alkoxide precursors, solvent, chelating agent and modifying liquid chemical materials such as triethanolamine or ammonium hydroxide. It was found to be YBCO, Gd 2 O 3 , NiO and Ni phases in YBCO/Gd 2 O 3 /Ni sample from XRD analysis. That the solution prepared by using triethanolamine provided the best film quality and

  18. Structural and superconducting properties of La2−xNdxCuO4+y (0≤x≤0.5) prepared by room temperature chemical oxidation

    DEFF Research Database (Denmark)

    Rial, C.; Morán, E.; Alario-Franco, M.A.

    1997-01-01

    The systematic characterization of the structural and superconducting properties of room temperature chemically oxidized T/O La2-xNdxCuO4+y (0 less than or equal to x less than or equal to 0.5) has been performed by neutron powder diffraction and magnetic susceptibility measurements. Similarities...

  19. Properties of alumina films prepared by metal-organic chemical vapour deposition at atmospheric pressure in hte presence of small amounts of water

    NARCIS (Netherlands)

    Haanappel, V.A.C.; Haanappel, V.A.C.; van Corbach, H.D.; Rem, J.B.; Fransen, T.; Gellings, P.J.

    1995-01-01

    Thin alumina films were deposited on stainless steel, type AISI 304. The deposition process was carried out in nitrogen with low partial pressures of water (0–2.6 × 10−2 kPa (0−0.20 mmHg)) by metal-organic chemical vapour deposition (MOCVD) with aluminium-tri-sec-butoxide (ATSB) as the precursor.

  20. Improvement of the preparation processes of oligoalginate by irradiation method combining with proper chemical treatment and applying the products on vegetables grown by hydroponics techniques

    International Nuclear Information System (INIS)

    Nguyen Huynh Phuong Uyen; Le Quang Luan; Le Thi Thuy Trang; Nguyen Thi Vang; Vo Thi Thu Ha; To Van Loi; Nguyen Hong An

    2015-01-01

    Degraded alginate extracted from brown seaweed compounds with molecular weights of 14.5 kDa was obtained by the Co-60 gamma ray irradiation at the absorbed dose of 5 kGy in presence of 0.5% H_2O_2. It was observed that the obtained oligo alginate promoted the growth of mustard greens and lettuce at an optimal concentration of 75 ppm and stimulated the plant height, root length, fresh biomass and dried matter content of the tested vegetables. The oligoalginate prepared by the irradiation under the presence of hydrogen peroxide showed growth promotion effects in the same level as the oligoalginate prepared by only irradiation. Note that the oligoalginate exhibited as a potential, safety and high effective product for plant growth promoter. (author)

  1. Physico-chemical characterisation, cytotoxic activity, and biocompatibility studies of tamoxifen-loaded solid lipid nanoparticles prepared via a temperature-modulated solidification method.

    Science.gov (United States)

    Lakkadwala, Sushant; Nguyen, Sanko; Lawrence, Joseph; Nauli, Surya M; Nesamony, Jerry

    2014-01-01

    Solid lipid nanoparticles (SLNs) can efficiently and efficaciously incorporate anti-cancer agents. To prepare and characterise tamoxifen (TAM)-loaded SLNs. Glyceryl monostearate, Tween-80, and trehalose were used in SLNs. SLNs were tested via dynamic light scattering (DLS), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Characterisation studies revealed SLNs of about 540 nm with a negative surface charge and confirmed the entrapment of TAM in the SLNs. The entrapment efficiency was estimated to be 60%. The in vitro drug release profile demonstrated a gradual increase followed by a release plateau for several days. A drug concentration-dependent increase in cytotoxic activity was observed when the SLNs were evaluated in cell cultures. Biocompatible and stable lyophilised SLNs were successfully prepared and found to possess properties that may be utilised in an anti-cancer drug delivery system.

  2. Chemical radioprotection

    International Nuclear Information System (INIS)

    Siegel, G.

    1979-01-01

    A reivew of the problems and progress in the field of chemical radioprotection is given. After defining the field of research, the practical significance of radioprotective substances and the requirements for a utilizable radioprotective preparation are presented. Trends of development of this field of research, the state of the art, and resulting conclusions for the future development of radioprotective substances of practical value are discussed. (author)

  3. Lab-on-Valve Micro Sequential Injection: A Versatile Approach for Implementing Integrated Sample Pre-preparations and Executing (Bio)Chemical Assays

    DEFF Research Database (Denmark)

    Hansen, Elo Harald

    waste generation. Most recently, the Lab-on-Valve (LOV) approach has emerged. Termed the third generation of FIA, the conceptual basis of the LOV is to incorporate all the necessary unit operational manipulations required in a chemical assay, and, when possible, even the detection device, into a single...... small integrated microconduit, or “laboratory”, placed atop a selection valve. In the lecture emphasis will be placed on the LOV approach. Proven itself as a versatile front end to a variety of detection techniques, its utility will be exemplified by various applications. Particular focus......-phase microcolumn concept utilising hydrophobic as well as hydrophilic bead materials. Although ETAAS and ICPMS both are characterised by excellent analytical chemical capabilities, they nevertheless often require that the samples be subjected to suitable pretreatment in order to obtain the necessary sensitivity...

  4. Preparation and surface characterization of activated carbons from Euphorbia rigida by chemical activation with ZnCl2, K2CO3, NaOH and H3PO4

    International Nuclear Information System (INIS)

    Kılıç, Murat; Apaydın-Varol, Esin; Pütün, Ayşe Eren

    2012-01-01

    Highlights: ► An arid land plant evaluated as low cost activated carbon precursor. ► Four types of different chemical activation agents are used. ► Higher surface area (2600 m 2 /g) obtained by chemical activation. ► Obtained activated carbon can be effectively used as an adsorbent for the removal of toxic pollutants from aqueous solutions. - Abstract: Preparation of activated carbons from Euphorbia rigida by chemical activation with different impregnation agents and ratios was studied. ZnCl 2 , K 2 CO 3 , NaOH and H 3 PO 4 were used as chemical activation agents and four impregnation ratios (25–50–75–100%) by mass were applied on biomass. Activation is applied to impregnated biomass samples at 700 °C under sweeping gas in a fixed bed reactor. For determination of chemical and physical properties of the obtained activated carbons; elemental analysis was applied to determine the elemental composition (C, H, N, O) and FT-IR spectra was used to analyze the functional groups. BET equation was used to calculate the surface areas of activated carbons. For understanding the changes in the surface structure, activated carbons were conducted to Scanning Electron Microscopy (SEM). Maximum BET surface area (2613 m 2 /g) was reached with 75% K 2 CO 3 impregnated biomass sample. Experimental results showed that impregnation types and ratios have a significant effect on the pore structure of activated carbon and E. rigida seems to be an alternative precursor for commercial activated carbon production.

  5. Gadolinium substitution for yttrium and chemical preparation effects in YBa{sub 2}Cu{sub 3}O{sub 7}: an EPR study; Effets de la substitution de l`yttrium par le gadolinium et de la preparation chimique dans YBa{sub 2}Cu{sub 3}O{sub 7}: etude par RPE

    Energy Technology Data Exchange (ETDEWEB)

    Bejjit, L.; Haddad, M. [Faculte des Sciences, Meknes (Morocco); Bejjit, L. [Faculte des Sciences, Errachidia (Morocco); Deville, A.; Gaillard, B.; Noel, H. [Universite de Provence, 13 - Marseille (France); Monnereau, O. [Universite de Rennes, 35 - Rennes (France)

    1998-01-01

    Compounds with yttrium totally or partially substituted by gadolinium in High-T{sub c} superconductor YBa{sub 2}Cu{sub 3}O{sub 7} were prepared. The superconductivity is not affected by this substitution. An orthorhombic structure has been observed in GdBa{sub 2}Cu{sub 3}O{sub 7} sintered and single crystals. The EPR measurements show linewidth dependence on chemical preparation in GdBa{sub 2}Cu{sub 3}O{sub 7}. In Gd-low concentration compounds (x{<=}0.02), a narrow parasite signal, due to the Y{sub 2}BaCuO{sub 5} green phase, appears superimposed to the principal Gd{sup 3+} ions Electron Spin Resonance (EPR) line. (authors) 12 refs.

  6. Physico-Chemical Characterization and Interfacial Electrochemical Properties of Nanoparticles of Anatase-TiO2 Prepared by the Sol-Gel Method

    Directory of Open Access Journals (Sweden)

    Ikram Daou

    2013-07-01

    Full Text Available In this work, we prepared by the sol-gel method titanium dioxide nanoparticles having a large specific area (SBET = 218 m2/g. The isotherm of N2 adsorption-desorption at 77K revealed that it concerns a mesoporous solid with a maximum pore diameter of 43 Å. The X-ray diffraction showed that the solid is constituted of the anatase phase. The transmission electron microscopy revealed us that the synthesized grains of TiO2 are of nanometric sizes (diameter between 8 and 20 nm and manifest under agglomerated shape. The study of its solubility in dispersing phase, by conductometric titrations, showed that the prepared solid is totally insoluble in all the domain of the studied pH. The measured inter-facial electrochemical properties, based on the isotherms of ionic adsorption and the conductometric titrations, are: the point of zero charge found equal to 6,2±0,1, the total number of sites of surface found equal to 5,8 OH/nm2 and the nature of action of the dispersed phase on the dispersing phase which is found organizer of the structure of water. Besides, the difference of the ionizationconstants pK is found superior to 4 for all the adsorbed ions and the constants of surface complexation are independent from the nature of the adsorbed ion.

  7. Hydrogels based on chemically modified poly(vinyl alcohol (PVA-GMA and PVA-GMA/chondroitin sulfate: Preparation and characterization

    Directory of Open Access Journals (Sweden)

    E. C. Muniz

    2012-05-01

    Full Text Available This work reports the preparation of hydrogels based on PVA-GMA, PVA-GMA is poly(vinyl alcohol (PVA functionalized with vinyl groups from glycidyl methacrylate (GMA, and on PVA-GMA with different content of chondroitin sulfate (CS. The degrees of swelling of PVA-GMA and PVA-GMA/CS hydrogels were evaluated in distilled water and the swelling kinetics was performed in simulated gastric and intestinal fluids (SGF and SIF. PVA-GMA and PVAGMA/CS hydrogels demonstrated to be resistant on SGF and SIF fluids. The elastic modulus, E, of swollen-hydrogels were determined through compressive tests and, according to the obtained results, the hydrogels presented good mechanical properties. At last, the presence of CS enhances the hydrogel cell compatibility as gathered by cytotoxicity assays. It was concluded that the hydrogels prepared through this work presented characteristics that allow them to be used as biomaterial, as a carrier in drug delivery system or to act as scaffolds in tissue engineering as well.

  8. Physical and Chemical Properties of TiOxNy Prepared by Low-Temperature Oxidation of Ultrathin Metal Nitride Directly Deposited on SiO2

    Institute of Scientific and Technical Information of China (English)

    HAN Yue-Ping; HAN Yan

    2009-01-01

    Physical and chemical properties of titanium oxynitride (TiOxNy) formed by low-temperature oxidation of titanium nitride (TIN) layer are investigated for advanced metal-oxide--semiconductor (MOS) gate dielectric application.TiOx Ny exhibits polycrystalline properties after the standard thermal process for MOS device fabrication,showing the preferred orientation at [200].Superior electrical properties of TiOxNy can be maintained before and after the annealing,probably due to the nitrogen incorporation in the oxide bulk and at the interface.Naturally formed transition layer between TiOxNy and SiO2 is also confirmed.

  9. Low temperature carrier transport study of monolayer MoS{sub 2} field effect transistors prepared by chemical vapor deposition under an atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xinke, E-mail: xkliu@szu.edu.cn, E-mail: wujing026@gmail.com; He, Jiazhu; Tang, Dan; Lu, Youming; Zhu, Deliang; Liu, Wenjun; Cao, Peijiang; Han, Sun [College of Materials Science and Engineering, Shenzhen Engineering Laboratory for Advanced Technology of Ceramics, Nanshan District Key Lab for Biopolymer and Safety Evaluation, Shenzhen University, 3688 Nanhai Ave, Shenzhen 518060 (China); Liu, Qiang; Wen, Jiao; Yu, Wenjie [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, CAS, 865 Chang Ning Road, Shanghai 200050 (China); Liu, Wenjun [State Key Laboratory of ASIC and System, Department of Microelectronics, Fudan University, 220 Handan Road, Shanghai 200433 (China); Wu, Jing, E-mail: xkliu@szu.edu.cn, E-mail: wujing026@gmail.com [Department of Physics, National University of Singapore, 21 Lower Kent Ridge Road, 117576 Singapore (Singapore); He, Zhubing [Department of Materials Science and Engineering, South University of Science and Technology of China, 1088 Xueyuan Road, Shenzhen 518055 (China); Ang, Kah-Wee [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, 117583 Singapore (Singapore)

    2015-09-28

    Large size monolayer Molybdenum disulphide (MoS{sub 2}) was successfully grown by chemical vapor deposition method under an atmospheric pressure. The electrical transport properties of the fabricated back-gate monolayer MoS{sub 2} field effect transistors (FETs) were investigated under low temperatures; a peak field effect mobility of 59 cm{sup 2}V{sup −1}s{sup −1} was achieved. With the assist of Raman measurement under low temperature, this work identified the mobility limiting factor for the monolayer MoS{sub 2} FETs: homopolar phonon scattering under low temperature and electron-polar optical phonon scattering at room temperature.

  10. Preference of multi-walled carbon nanotube (MWCNT) to single-walled carbon nanotube (SWCNT) and activated carbon for preparing silica nanohybrid pickering emulsion for chemical enhanced oil recovery (C-EOR)

    Energy Technology Data Exchange (ETDEWEB)

    AfzaliTabar, M. [Department of Chemistry, Islamic Azad University Branch of Tehran North, Tehran (Iran, Islamic Republic of); Alaei, M., E-mail: alaiem@ripi.ir [Nanotechnology Research Center, Research Institute of Petroleum Industry (RIPI), Tehran (Iran, Islamic Republic of); Ranjineh Khojasteh, R.; Motiee, F. [Department of Chemistry, Islamic Azad University Branch of Tehran North, Tehran (Iran, Islamic Republic of); Rashidi, A.M. [Nanotechnology Research Center, Research Institute of Petroleum Industry (RIPI), Tehran (Iran, Islamic Republic of)

    2017-01-15

    The aim of this research was to determine the best nano hybrid that can be used as a Pickering emulsion Chemical Enhanced Oil Recovery (C-EOR). Therefore, we have prepared different carbon structures nano hybrids with SiO{sub 2} nano particles with different weight percent using sol-gel method. The as-prepared nano materials were characterized with X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM) and Thermal Gravimetric Analysis (TGA). Pickering emulsions of these nanohybrids were prepared at pH=7 in ambient temperature and with distilled water. Stability of the mentioned Pickering emulsions was controlled for one month. Emulsion phase morphology was investigated using optical microscopic imaging. Evaluation results demonstrated that the best sample is the 70% MWCNT/SiO{sub 2} nanohybrid. Stability of the selected nanohybrid (70% MWCNT/SiO{sub 2} nanohybrid) was investigated by alteration of salinity, pH and temperature. Results showed that the mentioned Pickering emulsion has very good stability at 0.1%, 1% salinity, moderate and high temperature (25 °C and 90 °C) and neutral and alkaline pH (7, 10) that is suitable for the oil reservoirs conditions. The effect of the related nano fluid on the wettability of carbonate rock was investigated by measuring the contact angle and interfacial tension. Results show that the nanofluid could significantly change the wettability of the carbonate rock from oil wet to water wet and can decrease the interfacial tension. Therefore, the 70% MWCNT/SiO{sub 2} nanohybrid Pickering emulsion can be used for Chemical Enhanced Oil Recovery (C-EOR).

  11. Preference of multi-walled carbon nanotube (MWCNT) to single-walled carbon nanotube (SWCNT) and activated carbon for preparing silica nanohybrid pickering emulsion for chemical enhanced oil recovery (C-EOR)

    International Nuclear Information System (INIS)

    AfzaliTabar, M.; Alaei, M.; Ranjineh Khojasteh, R.; Motiee, F.; Rashidi, A.M.

    2017-01-01

    The aim of this research was to determine the best nano hybrid that can be used as a Pickering emulsion Chemical Enhanced Oil Recovery (C-EOR). Therefore, we have prepared different carbon structures nano hybrids with SiO 2 nano particles with different weight percent using sol-gel method. The as-prepared nano materials were characterized with X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM) and Thermal Gravimetric Analysis (TGA). Pickering emulsions of these nanohybrids were prepared at pH=7 in ambient temperature and with distilled water. Stability of the mentioned Pickering emulsions was controlled for one month. Emulsion phase morphology was investigated using optical microscopic imaging. Evaluation results demonstrated that the best sample is the 70% MWCNT/SiO 2 nanohybrid. Stability of the selected nanohybrid (70% MWCNT/SiO 2 nanohybrid) was investigated by alteration of salinity, pH and temperature. Results showed that the mentioned Pickering emulsion has very good stability at 0.1%, 1% salinity, moderate and high temperature (25 °C and 90 °C) and neutral and alkaline pH (7, 10) that is suitable for the oil reservoirs conditions. The effect of the related nano fluid on the wettability of carbonate rock was investigated by measuring the contact angle and interfacial tension. Results show that the nanofluid could significantly change the wettability of the carbonate rock from oil wet to water wet and can decrease the interfacial tension. Therefore, the 70% MWCNT/SiO 2 nanohybrid Pickering emulsion can be used for Chemical Enhanced Oil Recovery (C-EOR).

  12. Preparation and physico-chemical study of nitroxide radicals. Isotopic marking with carbon 13 and deuterium; Preparations et etudes physico-chimiques de radicaux nitroxydes. Marquage isotopique au carbone 13 et au deuterium

    Energy Technology Data Exchange (ETDEWEB)

    Chapelet-Letourneux, G [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1967-07-01

    N-t-butyl-N-phenyl nitroxide is obtained by: a) action of t-butyl-magnesium chloride on nitrobenzene, or of phenyl-magnesium bromide on nitro-t-butane, b) oxidation of N-t-butyl-N-phenylhydroxylamine, c) oxidation of N-t-butylaniline. In these latter two cases, it has been possible to isolate the pure radical and to study it using UV, IR and EPR. It decomposes to give N-t-butylaniline and the N-oxide of N-t-butyl-p-quinon-imine. The action of peracids such as p-nitro-perbenzoic or m-chloro-perbenzoic acids on amines or hydroxylamines leads to the formation of stable or unstable nitroxide radicals easily observable by EPR. Finally, with a view to obtaining definite values for the coupling between the free electron of a nitroxide and carbon 13, the preparation of such radicals marked with {sup 13}C in the {alpha} or {beta} position of the nitroxide function has been carried out. The coupling with an {alpha} carbon 13 is negative and does not appear to vary with the spin density on the nitrogen. The interaction with the p nuclei of the nitrogen depends on the nature of the substituents: the two benzyl protons have a hyperfine splitting a{sub H} which is always less than that of the ethyl. On the other hand, the {sup 13}C coupling is greater in the first case. The usually adopted conformations for the compounds having the carbonyl group cannot account for the observed values of the {beta} couplings. (author) [French] Le N-t-butyl-N-phenyl nitroxyde est obtenu par: a) action du chlorure de t-butylmagnesium sur le nitrobenzene, ou du bromure de phenylmagnesium sur le nitro-t-butane, b) oxydation de la N-t-butyl-N-phenylhydroxylamine, c) oxydation de la N-t-butylaniline. Dans ces deux derniers cas, le radical a pu etre isole pur et etudie par UV, IR et RPE. Il se decompose en N-t-butylaniline et N-oxyde de N-t-butyl-p-quinonimine. L'action de peracides (p-nitroperbenzoique ou m-chloroperbenzoique) sur des amines ou des hydroxylamines conduit a des radicaux nitroxydes

  13. Synthesis and photocatalytic application of α-Fe2O3/ZnO fine particles prepared by two-step chemical method

    Directory of Open Access Journals (Sweden)

    Patij Shah

    2013-06-01

    Full Text Available Composite iron oxide-Zinc oxide (α-Fe2O3/ZnO was synthesized by two-step method: in the first one step uniform α-Fe2O3 particles were prepared through a hydrolysis process of ferric chloride at 80 °C. In the second step, the ZnO particles were included in the α-Fe2O3 particles by a zinc acetate [Zn(Ac2·2H2O] assisted hydrothermal method at low temperature (90°C±C. The α-Fe2O3 and ZnO phases were identified by XRD, energy dispersive X-ray analysis (EDX. The photoreactivities of α-Fe2O3/ZnO nanoparticles under UV irradiation were quantified by the degradation of formaldehyde.

  14. Structure, chemical bonding states, and optical properties of the hetero-structured ZnO/CuO prepared by using the hydrothermal and the electrospinning methods

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Kyong-Soo; Kim, Jong Wook; Bae, Jong-Seong; Hong, Tae Eun; Jeong, Euh Duck; Jin, Jong Sung; Ha, Myoung Gyu; Kim, Jong-Pil, E-mail: jpkim@kbsi.re.kr

    2017-01-01

    ZnO-branched nanostructures have recently attracted considerable attention due to their rich architectures and promising applications in the field of optoelectronics. Contrary to n-type semiconducting metal oxides, cupric oxide is a p-type semiconductor which can be applied to high-critical-temperature superconductors, photovoltaic materials, field emission, and catalysis. We report the synthesis of the ZnO nanorods on the CuO nanofibers prepared by using the electrospinning method along with the hydrothermal method. As the growing time increases, emission spectra of the hetero-structured ZnO/CuO show that the observed band in the UV region is slightly increased, while the intensity of the green emission is highly enhanced. The hetero-structured ZnO/CuO is found to be a promising candidate for developing renewable devices with photoluminescent behavior and the increased surface to volume ratio.

  15. Ferroelectric properties of Bi3.25Ce0.75Ti3O12 thin films prepared by a liquid source misted chemical deposition

    International Nuclear Information System (INIS)

    Jeon, M.K.; Chung, H.J.; Kim, K.W.; Oh, K.S.; Woo, S.I.

    2005-01-01

    Cerium-substituted bismuth titanate (Bi 3.25 Ce 0.75 Ti 3 O 12 (BCT)) films were deposited on the Pt(111)/SiO 2 /Si(100) substrates by a liquid source misted chemical deposition technique. This film showed X-ray diffraction patterns that crystallization along the (006) direction was suppressed and did not contain any other oxides. The remnant polarization of this film increased with increase in annealing temperature. The 2P r and 2E c values of the BCT film annealed at 700 deg. C were 19.72 μC/cm 2 and 357 kV/cm, respectively. 2P r value of this film decreased by less than 5% of the initial value after 7 x 10 9 read/write switching cycles at a frequency of 1 MHz

  16. Chemical consequences resulting from multi-millicurie preparation of 6-[18F]-fluoro-6-deoxy-L-ascorbic acid

    International Nuclear Information System (INIS)

    Kothari, P.J.; Finn, R.D.; Bornmann, W.G.; Agus, D.B.; Vera, J.C.; Larson, S.M.

    1997-01-01

    Ascorbic acid is required for human physiology and is particularly important in maintaining normal connective tissue and host defense. Our interest in this carboxylic acid stems from its similarity in transport with glucose in human cells. In order to investigate these phenomena, we report a refined synthesis of 6-[ 18 F]-fluoro-6-deoxy-L-ascorbic acid ( 18 F-FAA) via nucleophilic displacement of the cyclic sulfate with Kryptofix 2.2.2/K 18 F complex which results in multi-millicurie quantities of high specific activity product. The trace carrier-added synthesis has resulted in a decay corrected radiochemical yield of 31.6±3.4% with a specific activity approaching 180 mCi/μmol. Our preliminary experience with the assessment of the chemical stability of both the radiolabelled and stable product is also presented. (orig.)

  17. Chemical treatment of wastewaters produced during separation of iodine 131; Traitement chimique des eaux residuaires provenant de la preparation d'iode-131

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, P.; Marcaillou, J.; Amavis, R.

    1959-06-22

    The authors report the development and assessment of a chemical treatment of radioactive wastewaters by co-precipitation. This treatment is aimed at replacing a treatment based on the use of calcium phosphate which proved to be insufficient for wastewaters resulting from the production of iodine 131. After a presentation of the characteristics of the effluents to be processed, the authors report co-precipitation tests performed on effluents before release in the storage vessel (by using barium hydroxide, lead acetate or lead sulfate) and on effluents diluted on the storage vessel. They show that a co-precipitation method based on the use of lead sulfate in alkaline medium gives the best results.

  18. Lab-on-Valve Micro Sequential Injection: A Versatile Approach for Implementing Integrated Sample Pre-preparations and Executing (Bio)Chemical Assays

    DEFF Research Database (Denmark)

    Hansen, Elo Harald

    waste generation. Most recently, the socalled third generation of FIA has emerged, that is, the Lab-on-Valve (LOV) approach, the conceptual basis of which is to incorporate all the necessary unit operational manipulations required, and, when possible, even the detection device into a single small...... integrated microconduit, or “laboratory”, placed atop a selection valve. The lecture will detail the evolution of the three generations of FIA, emphasis being placed on the LOV approach. Proven itself as a versatile front end to a variety of detection techniques, its utility will be exemplified by a series...... of the renewable microcolumn concept. Despite their excellent analytical chemical capabilities, ETAAS as well as ICPMS often require that the samples are subjected to suitable pretreatment in order to obtain the necessary sensitivity and selectivity. Either in order to separate the analyte from potentially...

  19. Characterization of Pb(Zr, Ti)O sub 3 thin films prepared by metal-organic chemical-vapor deposition using a solid delivery system

    CERN Document Server

    Shin, J C; Hwang, C S; Kim, H J; Lee, J M

    1999-01-01

    Pb(Zr, Ti)O sub 3 (PZT) thin films were deposited on Pt/SiO sub 2 /Si substrates by metal-organic chemical-vapor deposition technique using a solid delivery system to improve the reproducibility of the deposition. The self-regulation mechanism, controlling the Pb-content of the film, was observed to work above a substrate temperature of 620 .deg. C. Even with the self-regulation mechanism, PZT films having low leakage current were obtained only when the molar mixing ratio of the input precursors was 1

  20. Synthesis and characterization of structural, morphological and photosensor properties of Cu0.1Zn0.9S thin film prepared by a facile chemical method

    Science.gov (United States)

    Gubari, Ghamdan M. M.; Ibrahim Mohammed S., M.; Huse, Nanasaheb P.; Dive, Avinash S.; Sharma, Ramphal

    2018-05-01

    The Cu0.1Zn0.9S thin film was grown by facile chemical bath deposition (CBD) method on glass substrates at 60°C. The structural, morphological, photosensor properties of the as-grown thin film has been investigated. The structural and phase confirmation of the as-grown thin film was carried out by X-ray diffraction (XRD) technique and Raman spectroscopy. The FE-SEM images showed that the thin films are well covered with material on an entire glass substrate. From the optical absorption spectrum, the direct band gap energy for the Cu0.1Zn0.9S thin film was found to be ˜3.16 eV at room temperature. The electrical properties were measured at room temperature in the voltage range ±2.5 V, showed a drastic enhancement in current under light illumination with the highest photosensitivity of ˜72 % for 260 W.

  1. Effect of nickel oxide seed layers on annealed-amorphous titanium oxide thin films prepared using plasma-enhanced chemical vapor deposition

    International Nuclear Information System (INIS)

    Wu, Cheng-Yang; Hong, Shao-Chyang; Hwang, Fu-Tsai; Lai, Li-Wen; Lin, Tan-Wei; Liu, Day-Shan

    2011-01-01

    The effect of a nickel oxide (NiO x ) seed layer on the crystallization and photocatalytic activity of the sequentially plasma-enhanced chemical vapor deposited amorphous titanium oxide (TiO x ) thin film processed by a post-annealing process was investigated. The evolution of the crystalline structures, chemical bond configurations, and surface/cross-sectional morphologies of the annealed TiO x films, with and without a NiO x seed layer, was examined using X-ray diffractometer, Fourier transform infrared spectrometry, X-ray photoelectron spectroscopy, atomic force microscopy, and field emission scanning electron microscope measurements. Thermo- and photo-induced hydrophilicity was determined by measuring the contact angle of water droplet. Photocatalytic activity after UV light irradiation was evaluated from the decolorization of a methylene blue solution. The crystallization temperature of the TiO x film, deposited on a NiO x seed layer, was found to be lower than that of a pure TiO x film, further improving the thermo- and photo-induced surface super-hydrophilicity. The TiO x film deposited onto the NiO x seed layer, resulting in significant cluster boundaries, showed a rough surface morphology and proved to alleviate the anatase crystal growth by increasing the post-annealing temperature, which yielded a more active surface area and prohibited the recombination of photogenerated electrons and holes. The photocatalytic activity of the NiO x /TiO x system with such a textured surface therefore was enhanced and optimized through an adequate post-annealing process.

  2. Effect of anionic dopants on thickness, morphology and electrical properties of polypyrrole ultra-thin films prepared by in situ chemical polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Mahmoodian, Mehrnoosh [Dep. of Polymer Engineering, Nanostructured Materials Research Center, Sahand University of Technology, Tabriz 51335-1996 (Iran, Islamic Republic of); Pourabbas, Behzad, E-mail: pourabas@sut.ac.ir [Dep. of Polymer Engineering, Nanostructured Materials Research Center, Sahand University of Technology, Tabriz 51335-1996 (Iran, Islamic Republic of); Mohajerzadeh, Shams [Nano-Electronics and Thin Film Lab, School of Electrical and Computer Engineering, University of Tehran, P.O. Box 14395/515, Tehran (Iran, Islamic Republic of)

    2015-05-29

    The effect of different dopant anions on deposition and characteristics of polypyrrole (PPy) thin film has been studied in this work. Ultra-thin films of conducting PPy were deposited on insulating surfaces of glass and oxidized silicon wafer by in situ chemical polymerization in the presence of different anionic dopants including sodium dodecylbenzenesulfonate, sodium dodecyl sulfate, α-naphthalene sulfonic acid, anthraquinone-2-sulfonic acid sodium salt monohydrate/5-sulfosalicylic acid dehydrate, and camphor sulfonic acid. Hydrophilic/hydrophobic properties and morphology of the self-assembled monolayer of N-(3-trimethoxysilylpropyl)pyrrole, the surface modifying agent in this work, and PPy thin films were characterized before and after deposition by contact angle measurements, field emission scanning electron microscopy, and atomic force microscopy. Chemical structure, thickness, and conductivity of the thin films were also studied by attenuated total reflectance Fourier transform infrared spectrometer, ellipsometry, and four-point probe measurements. The results showed deposition of thin films of conducting PPy with comparable thickness in the range of 6-31 nm and different morphologies, uniformity, and smoothness with average roughness in the range of 0.3-6 nm and relatively high range of conductivity on the modified surfaces. - Highlights: • Conducting thin films of polypyrrole were deposited on glass and SiO{sub 2} substrates. • Surface modification using pyrrole-silane was employed prior to polymerization. • Films as thin as ≈ 7 nm were deposited using different surfactant/counter ions. • Chemistry of the counter ion affects thickness, conductivity and morphology. • Lower thickness/higher conductivity were obtained by structurally flexible dopants.

  3. Characteristics of SiOx-containing hard film prepared by low temperature plasma enhanced chemical vapor deposition using hexamethyldisilazane or vinyltrimethylsilane and post oxygen plasma treatment

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Yi-Syuan; Liu, Wan-Yu; Wu, Hsin-Ming [Department of Materials Engineering, Tatung University, Taipei, 104, Taiwan (China); Chen, Ko-Shao, E-mail: kschen@ttu.edu.tw [Department of Materials Engineering, Tatung University, Taipei, 104, Taiwan (China); Cech, Vladimir [Institute of Materials Chemistry, Brno University of Technology (Czech Republic)

    2017-03-01

    This study, monomers of hexamethyldisilazane (HMDSZ) and vinyltrimethylsilane (VTMS) were respectively used to deposit on the surface of polyethylene terephthalate (PET) substrate by plasma enhanced chemical vapor deposition. Oxygen plasma treatment follows the HMDSZ and VTMS deposition to produce a hydrophilic surface film on the deposited surface. Time for HMDSZ and VTMS plasma deposition was changed to investigate its influences on water contact angle, deposited film thickness, refractive index, and friction coefficient properties. The surface morphologies of the processed samples were observed by scanning electron microscope and their chemical compositions were measured by X-ray photoelectron spectroscopy. At 550 nm wavelength, the optical transmittance of PET after the HMDSZ treatment decreases from 89% to 83%, but increases from 89% to 95% for the VTMS treatment. With increase in HMDSZ and VTMS deposition times, the film thickness increases and the refractive index decreases. Result revealed by XPS, SiO{sub 2} film is formed on the sample surface after the O{sub 2} plasma treatment. The film adhesion capability by the HMDSZ+O{sub 2} and VTMS+O{sub 2} treatment was stronger than that by the HMDSZ and VTMS treatment only. The SiOx films produced by HMDSZ+O{sub 2} and VTMS+O{sub 2} treatment can increase the film hardness and improve light transmittance. - Highlights: • With increase in HMDSZ and VTMS deposition times, the film thickness increases and the refractive index decreases. • The optical transmittance of PET after the VTMS treatment increases from 89% to 95%. • The SiO{sub 2} films deposited by HMDSZ+O{sub 2} and VTMS+O{sub 2} plasma can increase the film hardness and improve light transmittance. • It is expected that they can be applied to the optical transmittance protective film on plastic substrate in the future.

  4. Preparation of five 3-MCPD fatty acid esters, and the effects of their chemical structures on acute oral toxicity in Swiss mice.

    Science.gov (United States)

    Liu, Man; Liu, Jie; Wu, Yizhen; Gao, Boyan; Wu, Pingping; Shi, Haiming; Sun, Xiangjun; Huang, Haiqiu; Wang, Thomas Ty; Yu, Liangli Lucy

    2017-02-01

    3-monochloro-1, 2-propanediol fatty acid esters (3-MCPDEs) comprise a group of food toxicants formed during food processing. 3-MCPDEs have received increasing attention concerning their potential negative effects on human health. However, reports on the toxicity of 3-MCPD esters are still limited. To determine the effects of fatty acid substitutions on the toxicity of their esters, 1-stearic, 1-oleic, 1-linoleic, 1-linoleic-2-palmitic and 1-palmitic-2-linoleic acid esters of 3-MCPD were synthesized and evaluated with respect to their acute oral toxicities in Swiss mice. 3-MCPDEs were obtained through the reaction of 3-MCPD and fatty acid chlorides, and their purities and structures were characterized by ultraperformance liquid chromatography-quadrupole-time of flight-mass spectrometry (UPLC-Q-TOF-MS), infrared, 1 H and 13 C spectroscopic analyses. Medial lethal doses of 1-stearic, 1-oleic, 1-linoleic, 1-linoleic-2-palmitic and 1-palmitic-2-linoleic acid esters were 2973.8, 2081.4, 2016.3, 5000 and > 5000 mg kg -1 body weight. For the first time, 3-MCPDEs were observed for their toxic effects in the thymus and lung. In addition, major histopathological changes, as well as blood urea nitrogen and creatinine, were examined for mice fed the five 3-MCPDEs. The results from the present study suggest that the degree of unsaturation, chain length, number of substitution and relative substitution locations of fatty acids might alter the toxicity of 3-MCPDEs. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  5. Study on pure and Nd-doped BiFeO{sub 3} thin films prepared by chemical solution deposition method

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Xu, E-mail: xuexu9@163.com; Tan, Guoqiang, E-mail: tan3114@163.com; Liu, Wenlong; Hao, Hangfei

    2014-08-01

    Highlights: • The composition of the precursor plays a crucial role in BFO. • The ferroelectric–paraelectric phase transition through Nd substitution. • The significant enhancement in magnetization is observed in orthorhombic BNFO. • The highest magnetocapacitance is observed at x = 0.15. • The band gap of BNFO can be expressed as E{sub g} = (2.45 − 0.024x) eV. - Abstract: Polycrystalline BiFeO{sub 3} (BFO) films with varying precursor composition and Bi{sub 1−x}Nd{sub x}FeO{sub 3} (BNFO, x = 0.06–0.20) films were deposited on FTO substrates by using a chemical solution deposition method. Present data indicated that the precursor played a crucial role, i.e., microstructure, morphology and ferroelectric properties of the BFO film are closely related to the proportion of acetic anhydride. XRD analysis and Raman spectra revealed a structural transition from rhombohedral to tetragonal as the amount of acetic anhydride was increased. The effect of Nd on microstructure, chemical state, dielectric, ferroelectric, magnetic and optical properties has been investigated. A structural transition with increasing Nd content was proved by using XRD and Raman scattering spectra. X-ray photoelectron spectroscopy confirmed the formation of Fe{sup 2+} and the valence fluctuation of Bi of the BNFO films. The strongest ferroelectric polarization and magnetocapacitance were obtained in the sample with 15% Nd. A dramatic reduction in ferroelectric polarization and the strongest magnetization were observed in the BNFO (x = 0.20) film due to its paraelectric nature and orthorhombic structure. With increasing Nd content, the band gap of the BNFO films decreased with E{sub g} = (2.45 − 0.024x) eV.

  6. Effect of nickel oxide seed layers on annealed-amorphous titanium oxide thin films prepared using plasma-enhanced chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Cheng-Yang; Hong, Shao-Chyang [Institute of Electro-Optical and Materials Science, National Formosa University, Huwei, Yunlin, 63201, Taiwan (China); Hwang, Fu-Tsai [Department of Electro-Optical Engineering, National United University, Miao-Li, 36003, Taiwan (China); Lai, Li-Wen [ITRI South, Industrial Technology Research Institute, Liujia, Tainan, 73445, Taiwan (China); Lin, Tan-Wei [Institute of Electro-Optical and Materials Science, National Formosa University, Huwei, Yunlin, 63201, Taiwan (China); Liu, Day-Shan, E-mail: dsliu@sunws.nfu.edu.tw [Institute of Electro-Optical and Materials Science, National Formosa University, Huwei, Yunlin, 63201, Taiwan (China)

    2011-10-31

    The effect of a nickel oxide (NiO{sub x}) seed layer on the crystallization and photocatalytic activity of the sequentially plasma-enhanced chemical vapor deposited amorphous titanium oxide (TiO{sub x}) thin film processed by a post-annealing process was investigated. The evolution of the crystalline structures, chemical bond configurations, and surface/cross-sectional morphologies of the annealed TiO{sub x} films, with and without a NiO{sub x} seed layer, was examined using X-ray diffractometer, Fourier transform infrared spectrometry, X-ray photoelectron spectroscopy, atomic force microscopy, and field emission scanning electron microscope measurements. Thermo- and photo-induced hydrophilicity was determined by measuring the contact angle of water droplet. Photocatalytic activity after UV light irradiation was evaluated from the decolorization of a methylene blue solution. The crystallization temperature of the TiO{sub x} film, deposited on a NiO{sub x} seed layer, was found to be lower than that of a pure TiO{sub x} film, further improving the thermo- and photo-induced surface super-hydrophilicity. The TiO{sub x} film deposited onto the NiO{sub x} seed layer, resulting in significant cluster boundaries, showed a rough surface morphology and proved to alleviate the anatase crystal growth by increasing the post-annealing temperature, which yielded a more active surface area and prohibited the recombination of photogenerated electrons and holes. The photocatalytic activity of the NiO{sub x}/TiO{sub x} system with such a textured surface therefore was enhanced and optimized through an adequate post-annealing process.

  7. Wet chemical preparation of YVO{sub 4}:Eu thin films as red-emitting phosphor layers for fully transparent flat dielectric discharge lamp

    Energy Technology Data Exchange (ETDEWEB)

    Klausch, A. [Institute for Inorganic Chemistry, Dresden University of Technology, Mommsenstr. 6, 01069 Dresden (Germany); Althues, H. [Fraunhofer Institute for Material and Beam Technology Winterbergstr. 28, 01309 Dresden (Germany); Freudenberg, T. [Leibniz Institute for Solid State and Materials Research, Helmholtzstrasse 20, 01069 Dresden (Germany); Kaskel, S., E-mail: Stefan.Kaskel@chemie.tu-dresden.de [Institute for Inorganic Chemistry, Dresden University of Technology, Mommsenstr. 6, 01069 Dresden (Germany)

    2012-04-30

    Highly transparent YVO{sub 4}:Eu thin films were deposited via dip coating of liquid nanoparticle dispersions on glass substrates. Annealing of the nanoparticle layers resulted in restructuring of the material into oriented crystalline films. The crystallinity was confirmed using powder X-ray diffraction. Film thickness was adjusted to 467 nm by multiple deposition. The resulting coatings show > 99% absorbance for wavelength below 300 nm and > 90% transmission in the visible spectral range. Under UV-light excitation a bright red photoluminescence with a quantum efficiency of 20% is observed. A planar, transparent dielectric barrier discharge lamp was constructed using YVO{sub 4}:Eu coated glasses and transparent electrodes made from antimony-doped tin dioxide thin films. - Highlights: Black-Right-Pointing-Pointer Preparation of highly transparent Eu{sup 3+} doped YVO{sub 4} phosphor thin films. Black-Right-Pointing-Pointer Improved crystallinity and optical properties through heat treatment. Black-Right-Pointing-Pointer Red emitting films on glass substrates were combined with antimony tin oxide thin films. Black-Right-Pointing-Pointer Fully transparent, planar gas discharge lamp as prototype for a light emitting window.

  8. Preparation of diatomite/Ca(OH){sub 2} sorbents and modelling their sulphation reaction Istanbul Technical University, Istanbul (Turkey). Chemical and Metallurgical Engineering Faculty

    Energy Technology Data Exchange (ETDEWEB)

    Nilgun Karatepe; Nilufer Erdoan; Aysegul Ersoy-Mericboyu; Sadriye Kucukbayrak

    2004-09-01

    Mixtures of Ca(OH){sub 2} and diatomite were hydrated at different conditions to produce reactive SO{sub 2} sorbents. Two different hydration techniques were used; namely, atmospheric and pressure hydration. The effect of the hydration temperature, time and diatomite/Ca(OH){sub 2} weight ratio on the physical properties of the activated sorbents were investigated. In atmospheric hydration, it was found that increasing the temperature and hydration time caused an increase in the total surface area of the sorbents. However, surface area values of the sorbents prepared from mixtures which have different diatomite/Ca(OH){sub 2} weight ratio were generally not changed significantly. In pressure hydration, the surface area of the activated sorbents was positively affected from the hydration temperature and pressure. Finally, Ca(OH){sub 2} and two diatomite/Ca(OH){sub 2} sorbents were sulphated at constant temperature (338 K) using a synthetic gaseous mixture consisting of 5% O{sub 2}, 10% CO{sub 2}, 5000 ppm SO{sub 2} and the balance of nitrogen with a 55% relative humidity. The sulphation reaction of these sorbents were investigated and modelled. The unreacted shrinking core model was chosen to describe this non-catalytic solid/gas (hydrated sorbent/SO{sub 2}) reaction mechanism. The experimental results were found to be correlated successfully by this model.

  9. Transport Properties, Mechanical Behavior, Thermal and Chemical Resistance of Asymmetric Flat Sheet Membrane Prepared from PSf/PVDF Blended Membrane on Gauze Supporting Layer

    Directory of Open Access Journals (Sweden)

    Nita Kusumawati

    2018-05-01

    Full Text Available Asymmetric polysulfone (PSf membrane is prepared using phase inversion method and blending with polyvinylidene fluoride (PVDF on the gauze solid support. Casting solution composition optimization has been done to get PSf/PVDF membrane with best characteristics and permeability. The result shows that blending on PSf with PVDF polymer using phase inversion method has been very helpful in creating an asymmetric porous membrane. Increased level of PVDF in casting solution has increased the formation of asymmetry structure and corresponding flux membrane. The result from thermal test using Differential Scanning Calorimetry (DSC-Thermal Gravimetric Analysis (TGA shows the resistance of the membrane to temperature 460 °C. Membrane resistance against acid looks from undetectable changes on infrared spectra after immersion process in H2SO4 6–98 v/v%. While membrane color changes from white to brownish and black is detected after the immersion process in sodium hydroxide (NaOH 0.15–80 w/v%.

  10. Chemical profiling of anti-hepatocellular carcinoma constituents from Caragana tangutica Maxim. by off-line semi-preparative HPLC-NMR.

    Science.gov (United States)

    Yang, Xinzhou; Huang, Mi; Cai, Jinyan; Lv, Dan; Lv, Jingnan; Zheng, Sijian; Ma, Xinhua; Zhao, Ping; Wang, Qiang

    2017-05-01

    An EtOAc fraction from the roots of Caragana tangutica Maxim. (CTEA) displayed promising anti-hepatocellular carcinoma (HCC) activity during screening of a traditional Chinese ethnic herb library against HepG2 and Hep3B cell lines. HPLC-based activity profiling of CTEA by combination of MS-guided large-scale semi-preparative HPLC and NMR methods led to the identification of a new pterocarpan glycoside, (-)-maackiain 3-O-6'-O-methyl malonyl-β-d-glucopyranoside (1), together with three known pterocarpan glycosides, (-)-maackiain 3-O-β-d-glucopyranoside (2), 3-O-6'-O-acrylyl-β-d-galactopyranoside (3), and (-)-maackiain 3-O-6'-O-acetyl-β-d-glucopyranoside (4). Compound 1 was isolated during a drug discovery programme aimed at identifying new anti-HCC leads from a natural product library. Anti-HCC study showed that all four compounds exhibited cytotoxic activity with IC 50 values range of 29.1-53.5 μg/mL against HepG2 and Hep3B cell lines.

  11. Enhanced photoluminescence and Raman properties of Al-Doped ZnO nanostructures prepared using thermal chemical vapor deposition of methanol assisted with heated brass.

    Directory of Open Access Journals (Sweden)

    Tamil Many K Thandavan

    Full Text Available Vapor phase transport (VPT assisted by mixture of methanol and acetone via thermal evaporation of brass (CuZn was used to prepare un-doped and Al-doped zinc oxide (ZnO nanostructures (NSs. The structure and morphology were characterized by field emission scanning electron microscopy (FESEM and x-ray diffraction (XRD. Photoluminescence (PL properties of un-doped and Al-doped ZnO showed significant changes in the optical properties providing evidence for several types of defects such as zinc interstitials (Zni, oxygen interstitials (Oi, zinc vacancy (Vzn, singly charged zinc vacancy (VZn-, oxygen vacancy (Vo, singly charged oxygen vacancy (Vo+ and oxygen anti-site defects (OZn in the grown NSs. The Al-doped ZnO NSs have exhibited shifted PL peaks at near band edge (NBE and red luminescence compared to the un-doped ZnO. The Raman scattering results provided evidence of Al doping into the ZnO NSs due to peak shift from 145 cm-1 to an anomalous peak at 138 cm-1. Presence of enhanced Raman signal at around 274 and 743 cm-1 further confirmed Al in ZnO NSs. The enhanced D and G band in all Al-doped ZnO NSs shows possible functionalization and doping process in ZnO NSs.

  12. Enhanced photoluminescence and Raman properties of Al-Doped ZnO nanostructures prepared using thermal chemical vapor deposition of methanol assisted with heated brass.

    Science.gov (United States)

    Thandavan, Tamil Many K; Gani, Siti Meriam Abdul; San Wong, Chiow; Md Nor, Roslan

    2015-01-01

    Vapor phase transport (VPT) assisted by mixture of methanol and acetone via thermal evaporation of brass (CuZn) was used to prepare un-doped and Al-doped zinc oxide (ZnO) nanostructures (NSs). The structure and morphology were characterized by field emission scanning electron microscopy (FESEM) and x-ray diffraction (XRD). Photoluminescence (PL) properties of un-doped and Al-doped ZnO showed significant changes in the optical properties providing evidence for several types of defects such as zinc interstitials (Zni), oxygen interstitials (Oi), zinc vacancy (Vzn), singly charged zinc vacancy (VZn-), oxygen vacancy (Vo), singly charged oxygen vacancy (Vo+) and oxygen anti-site defects (OZn) in the grown NSs. The Al-doped ZnO NSs have exhibited shifted PL peaks at near band edge (NBE) and red luminescence compared to the un-doped ZnO. The Raman scattering results provided evidence of Al doping into the ZnO NSs due to peak shift from 145 cm-1 to an anomalous peak at 138 cm-1. Presence of enhanced Raman signal at around 274 and 743 cm-1 further confirmed Al in ZnO NSs. The enhanced D and G band in all Al-doped ZnO NSs shows possible functionalization and doping process in ZnO NSs.

  13. Effect of reaction time on structural, morphology and optical properties of ZnO nanoflakes prepared by chemical bath deposition method

    Energy Technology Data Exchange (ETDEWEB)

    Molefe, F.V.; Koao, L.F., E-mail: koaolf@qwa.ufs.ac.za; Dolo, J.J.; Dejene, B.F.

    2014-04-15

    ZnO nanoflakes have been successfully synthesized by the chemical bath deposition (CBD) method for different reaction times. X-ray diffraction (XRD) results confirm the initial formation of the cubic ZnO structure. However, increasing the reaction time resulted into the emergence of the well-known hexagonal wurtzite structure of ZnO. Scanning electron microscopy images showed the presence of agglomerated nanoflakes. The morphology was found not to depend on synthesis time. UV–vis spectra showed a partially increase in the percentage reflectance and the absorption edges red shifted to the higher wavelength with an increase in synthesis time. The highest band gap energy was obtained for ZnO synthesized for 1 min, with its estimated band gap energy of 3.91±0.08 eV. The estimated band gap decreased with an increase in the reaction time. The photoluminescent intensity of the emission peak at 473 nm decreased with an increase in reaction time.

  14. Photooxidation of different organic dyes (RB, MO, TB, and BG) using Fe(III)-doped TiO2 nanophotocatalyst prepared by novel chemical method

    International Nuclear Information System (INIS)

    Ghorai, Tanmay K.; Biswas, Soumya K.; Pramanik, Panchanan

    2008-01-01

    The nano-structured Fe(III)-doped TiO 2 photocatalysts with anatase phase have been developed for the oxidation of non-biodegradable different organic dyes like methyl orange (MO), rhodamine B (RB), thymol blue (TB) and bromocresol green (BG) using UV-Hg-lamp. The different compositions of Fe x Ti 1-x O 2 (x = 0.005, 0.01, 0.05, and 0.1) nanocatalysts synthesized by chemical method (CM), have been characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectra, specific surface area (BET), transmission electronic microscopy (TEM) analysis, XPS, ESR and zeta potential. From XRD analysis, the results indicate that all the compositions of Fe(III) doped in TiO 2 catalysts gives only anatase phase not rutile phase. For complete degradation of all the solutions of the dyes (MO, RB, TB, and BG), the composition with x = 0.005 is more photoactive compared all other compositions of Fe x Ti 1-x O 2 , and degussa P25. The decolorization rate of different dyes decreases as Fe(III) concentration in TiO 2 increases. The energy band gap of Fe(III)-doped TiO 2 is found to be 2.38 eV. The oxidation state of iron has been found to be 3+ from XPS and ESR show that Fe 3+ is in low spin state

  15. Parametric optimisation of core–shell ZnS:Mn/ZnS nanoparticles prepared by ultrasound-controlled wet chemical route

    Energy Technology Data Exchange (ETDEWEB)

    Sen, Suranjan, E-mail: suranjansen@iitb.ac.in [National Centre for Photovoltaic Research and Education (NCPRE), IIT Bombay, Powai, Mumbai 400076 (India); Department of Energy Science and Engineering, IIT Bombay, Powai, Mumbai 400076 (India); Solanki, Chetan Singh, E-mail: chetanss@iitb.ac.in [National Centre for Photovoltaic Research and Education (NCPRE), IIT Bombay, Powai, Mumbai 400076 (India); Department of Energy Science and Engineering, IIT Bombay, Powai, Mumbai 400076 (India); Sharma, Pratibha, E-mail: pratibha_sharma@iitb.ac.in [National Centre for Photovoltaic Research and Education (NCPRE), IIT Bombay, Powai, Mumbai 400076 (India); Department of Energy Science and Engineering, IIT Bombay, Powai, Mumbai 400076 (India)

    2014-01-15

    Core–shell type manganese-doped zinc sulphide nanoparticles ZnS:Mn/ZnS, showing strong absorption of ultraviolet light in the 280–450 nm range and emitting orange-yellow light close to 600 nm, were synthesised for eventual deployment as wavelength down-shifters for solar cells. While most syntheses described in literature employed long reaction times and high reaction/annealing temperatures in excess of 100 °C, this work presents a facile low-temperature wet chemical route. Key synthesis parameters – including zinc to sulphur ratio, manganese doping percentage, reaction sequence and ultrasonication time – were optimised systematically to achieve optimum orange emission intensity. Nanoparticles with average size ∼2.3 nm and showing bright orange emission under UV excitation were ultimately achieved. Various characterisation techniques, namely HRTEM, XRD, ICP, ESR, UV–visible absorption spectrometry and fluorescence spectroscopy, were used to probe the nature of the sample. -- Highlights: • Shell formation achieved by ultrasonic decomposition of zinc–thiourea complex. • Optimal zinc to sulphur ratio in reaction mix was found to be 1:1.2. • Optimal manganese doping percentage was found to be 5.8%. • Addition of cationic precursors to anionic precursors proved to be favourable. • Ultrasonication times exceeding 15 min were detrimental to emission intensity.

  16. Impedance spectroscopy and morphology of SrBi{sub 4}Ti{sub 4}O{sub 15} ceramics prepared by soft chemical method

    Energy Technology Data Exchange (ETDEWEB)

    Rout, S.K. [Department of Chemical and Biomolecular Engineering, KAIST (Korea, Republic of); Department of Applied Physics, BIT, Mesra, Ranchi (India)], E-mail: drskrout@gmail.com; Hussian, Ali; Lee, J.S. [School of Materials Science and Engineering University of Ulsan (Korea, Republic of); Kim, I.W. [Department of Physics, University of Ulsan (Korea, Republic of); Woo, S.I. [Department of Chemical and Biomolecular Engineering, KAIST (Korea, Republic of)], E-mail: siwoo@kaist.ac.kr

    2009-05-27

    In this work, we have synthesized polycrystalline SrBi{sub 4}Ti{sub 4}O{sub 15} (SBiT) ceramics by soft chemical method. These ceramics were structurally characterized by analysis of X-ray diffraction (XRD) patterns, indicates that SBiT ceramics present an orthorhombic structure. Scanning electron micrograph shows that the grains exhibit a plate like morphology. Dielectric relaxations of the SBiT ceramics were investigated in the temperature range 100-700 deg. C. Using the Cole-Cole model, an analysis of the dielectric loss with frequency was performed, assuming a distribution of relaxation time. The presence of the peaks in temperature dependent dielectric loss indicates that the hoping of charge carriers is responsible for the relaxation. Impedance studies shows a non-Debye type relaxation, and relaxation frequency shift to higher side with increase in temperature. A significant shift in impedance loss peaks towards higher frequency side indicates conduction in material and favoring the long range motion of mobile charge carriers. The Nyquist plot shows overlapping semicircles, for grain and grain boundary of SBiT ceramics. The frequency dependent ac conductivity at different temperatures indicates that the conduction process is thermally activated process and the spectra follow the universal power law. The hopping frequency shifts towards higher frequency side with increase of temperature, below which the conductivity is frequency independent. The variation of dc conductivity confirms that the SBiT ceramics exhibits negative temperature coefficient of resistance behavior in high temperature.

  17. Impact of hydrogen dilution on optical properties of intrinsic hydrogenated amorphous silicon films prepared by high density plasma chemical vapor deposition for solar cell applications

    Science.gov (United States)

    Chen, Huai-Yi; Lee, Yao-Jen; Chang, Chien-Pin; Koo, Horng-Show; Lai, Chiung-Hui

    2013-01-01

    P-i-n single-junction hydrogenated amorphous silicon (a-Si:H) thin film solar cells were successfully fabricated in this study on a glass substrate by high density plasma chemical vapor deposition (HDP-CVD) at low power of 50 W, low temperature of 200°C and various hydrogen dilution ratios (R). The open circuit voltage (Voc ), short circuit current density (Jsc ), fill factor (FF) and conversion efficiency (η) of the solar cell as well as the refractive index (n) and absorption coefficient (α) of the i-layer at 600 nm wavelength rise with increasing R until an abrupt drop at high hydrogen dilution, i.e. R > 0.95. However, the optical energy bandgap (Eg ) of the i-layer decreases with the R increase. Voc and α are inversely correlated with Eg . The hydrogen content affects the i-layer and p/i interface quality of the a-Si:H thin film solar cell with an optimal value of R = 0.95, which corresponds to solar cell conversion efficiency of 3.85%. The proposed a-Si:H thin film solar cell is expected to be improved in performance.

  18. Modified DLC coatings prepared in a large-scale reactor by dual microwave/pulsed-DC plasma-activated chemical vapour deposition

    International Nuclear Information System (INIS)

    Corbella, C.; Bialuch, I.; Kleinschmidt, M.; Bewilogua, K.

    2008-01-01

    Diamond-Like Carbon (DLC) films find abundant applications as hard and protective coatings due to their excellent mechanical and tribological performances. The addition of new elements to the amorphous DLC matrix tunes the properties of this material, leading to an extension of its scope of applications. In order to scale up their production to a large plasma reactor, DLC films modified by silicon and oxygen additions have been grown in an industrial plant of 1m 3 by means of pulsed-DC plasma-activated chemical vapour deposition (PACVD). The use of an additional microwave (MW) source has intensified the glow discharge, partly by electron cyclotron resonance (ECR), accelerating therefore the deposition process. Hence, acetylene, tetramethylsilane (TMS) and hexamethyldisiloxane (HMDSO) constituted the respective gas precursors for the deposition of a-C:H (DLC), a-C:H:Si and a-C:H:Si:O films by dual MW/pulsed-DC PACVD. This work presents systematic studies of the deposition rate, hardness, adhesion, abrasive wear and water contact angle aimed to optimize the technological parameters of deposition: gas pressure, relative gas flow of the monomers and input power. This study has been completed with measures of the atomic composition of the samples. Deposition rates around 1 μm/h, typical for standard processes held in the large reactor, were increased about by a factor 10 when the ionization source has been operated in ECR mode

  19. Effect of the hydrogen flow rate on the structural and optical properties of hydrogenated amorphous silicon thin films prepared by plasma enhanced chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Ben Amor, Sana; Dimassi, Wissem; Ali Tebai, Mohamed; Ezzaouia, Hatem [Photovoltaic Laboratory Research and Technology Centre of Energy, Borj-Cedria Science and Technology Park, BP 95, 2050 Hammam-Lif (Tunisia)

    2012-10-15

    Hydrogenated amorphous silicon (a-Si:H) thin films were deposited from pure silane (SiH{sub 4}) and hydrogen (H{sub 2}) gas mixture by plasma enhanced chemical vapor deposition (PECVD) method at low temperature (400 C) using high rf power (60 W). The structural and optical properties of these films are systematically investigated as a function of the flow rate of hydrogen (F{sub H2}).The surface morphology is analyzed by atomic force microscopy (AFM). The characterization of these films with low angle X-ray diffraction revealed that the crystallite size in the films tends to decrease with increase in (F{sub H2}). The Fourier transform infrared (FTIR) spectroscopic analysis showed that at low values of (F{sub H2}),the hydrogen bonding in Si:H films shifts from di-hydrogen (Si-H{sub 2}) and (Si-H{sub 2})n complexes to the mono-hydrogen (Si-H) bonding configuration. Finally, for these optimized conditions, the deposition rate decreases with increasing (F{sub H2}). (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  20. Production and evaluation of mineral and nutrient contents, chemical composition, and sensory properties of ice creams fortified with laboratory-prepared peach fibre

    Science.gov (United States)

    Yangılar, Filiz

    2016-01-01

    Background In the coming years, a nutraceutical food may provide both physical and mental benefits that are commonly attributed to the active components of the food. Objective In this study, we determined the nutrient and mineral contents, sensory properties, and physical and chemical characteristics of ice creams manufactured using peach fibre at different concentrations (1 and 2%). Method A total of five experimental groups were formed: two types (from peach peel and pulp) of flour, two fibre concentrations (1 and 2%), and a control group without fibres. Results Flour obtained from peach pulp and peel was found to have a significant (pice cream samples, especially the rates of Ca, K, Mg, and P, which increased in the samples depending on the content of peach fibre. Sensory ratings and acceptability of ice creams decreased significantly with increasing peach peel fibre, whereas ice creams made with C (control) and B1 (ice creams made from 1% peach pulp fibre) was the highest scored by the panellists. Conclusions Peach fibre concentrates might be used as a good source of nutraceutical ingredients. PMID:27814781

  1. Dielectric properties of Ca(Zr0.05Ti0.95)O3 thin films prepared by chemical solution deposition

    International Nuclear Information System (INIS)

    Cavalcante, L.S.; Simoes, A.Z.; Santos, L.P.S.; Santos, M.R.M.C.; Longo, E.; Varela, J.A.

    2006-01-01

    Ca(Zr 0.05 Ti 0.95 )O 3 (CZT) thin films were grown on Pt(111)/Ti/SiO 2 /Si(100) substrates by the soft chemical method. The films were deposited from spin-coating technique and annealed at 928K for 4h under oxygen atmosphere. CZT films present orthorhombic structure with a crack free and granular microstructure. Atomic force microscopy and field-emission scanning electron microscopy showed that CZT present grains with about 47nm and thickness about 450nm. Dielectric constant and dielectric loss of the films was approximately 210 at 100kHz and 0.032 at 1MHz. The Au/CZT/Pt capacitor shows a hysteresis loop with remnant polarization of 2.5μC/cm 2 , and coercive field of 18kV/cm, at an applied voltage of 6V. The leakage current density was about 4.6x10 -8 A/cm 2 at 3V. Dielectric constant-voltage curve is located at zero bias field suggesting the absence of internal electric fields

  2. Low-Temperature Preparation of (111)-oriented Pb(Zr,Ti)O3 Films Using Lattice-Matched (111)SrRuO3/Pt Bottom Electrode by Metal-Organic Chemical Vapor Deposition

    Science.gov (United States)

    Kuwabara, Hiroki; Sumi, Akihiro; Okamoto, Shoji; Hoko, Hiromasa; Cross, Jeffrey S.; Funakubo, Hiroshi

    2009-04-01

    Pb(Zr0.35Ti0.65)O3 (PZT) films 170 nm thick were prepared at 415 °C by pulsed metal-organic chemical vapor deposition. The (111)-oriented PZT films with local epitaxial growth were obtained on (111)SrRuO3/(111)Pt/TiO2/SiO2/Si substrates and their ferroelectricities were ascertained. Ferroelectricity was improved by postannealing under O2 gas flow up to 550 °C. Larger remanent polarization and better fatigue endurance were obtained using a SrRuO3 top electrode compared to a Pt top electrode for PZT films after annealing at 500 °C.

  3. Depleting high-abundant and enriching low-abundant proteins in human serum: An evaluation of sample preparation methods using magnetic nanoparticle, chemical depletion and immunoaffinity techniques.

    Science.gov (United States)

    de Jesus, Jemmyson Romário; da Silva Fernandes, Rafael; de Souza Pessôa, Gustavo; Raimundo, Ivo Milton; Arruda, Marco Aurélio Zezzi

    2017-08-01

    The efficiency of three different depletion methods to remove the most abundant proteins, enriching those human serum proteins with low abundance is checked to make more efficient the search and discovery of biomarkers. These methods utilize magnetic nanoparticles (MNPs), chemical reagents (sequential application of dithiothreitol and acetonitrile, DTT/ACN), and commercial apparatus based on immunoaffinity (ProteoMiner, PM). The comparison between methods shows significant removal of abundant protein, remaining in the supernatant at concentrations of 4.6±0.2, 3.6±0.1, and 3.3±0.2µgµL -1 (n=3) for MNPs, DTT/ACN and PM respectively, from a total protein content of 54µgµL -1 . Using GeLC-MS/MS analysis, MNPs depletion shows good efficiency in removing high molecular weight proteins (>80kDa). Due to the synergic effect between the reagents DTT and ACN, DTT/ACN-based depletion offers good performance in the depletion of thiol-rich proteins, such as albumin and transferrin (DTT action), as well as of high molecular weight proteins (ACN action). Furthermore, PM equalization confirms its efficiency in concentrating low-abundant proteins, decreasing the dynamic range of protein levels in human serum. Direct comparison between the treatments reveals 72 proteins identified when using MNP depletion (43 of them exclusively by this method), but only 20 proteins using DTT/ACN (seven exclusively by this method). Additionally, after PM treatment 30 proteins were identified, seven exclusively by this method. Thus, MNPs and DTT/ACN depletion can be simple, quick, cheap, and robust alternatives for immunochemistry-based protein depletion, providing a potential strategy in the search for disease biomarkers. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Preparation and characterization of activated carbon from reedy grass leaves by chemical activation with H{sub 3}PO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jianzhong, E-mail: xjz8112@sina.com [College of Chemistry and Environmental Science, Hebei University, Baoding 071002, Hebei (China); Chen, Lingzhi [College of Chemistry and Environmental Science, Hebei University, Baoding 071002, Hebei (China); Department of Applied Chemistry, Hengshui University, Hengshui 053000, Hebei (China); Qu, Hongqiang; Jiao, Yunhong; Xie, Jixing [College of Chemistry and Environmental Science, Hebei University, Baoding 071002, Hebei (China); Xing, Guangen [Department of Applied Chemistry, Hengshui University, Hengshui 053000, Hebei (China)

    2014-11-30

    Highlights: • Activated carbons were produced from reedy grass leaves by activation with phosphoric acid. • The activated carbons have a large number of oxygen- and phosphorus-containing surface groups. • The structure of activated carbons was bight fibers features on the surface and the external surface of the activated carbons was slightly corrugated and abundant pores. - Abstract: Activated carbons were produced from reedy grass leaves by chemical activation with H{sub 3}PO{sub 4} in N{sub 2} atmosphere and their characteristics were investigated. The effects of activation temperature and time were examined. Adsorption capacity was demonstrated with BET and iodine number. Micropore volume and pore size distribution of activated carbons were characterized by N{sub 2} adsorption isotherms. The surface area and iodine number of the activated carbons produced at 500 °C for 2 h were 1474 m{sup 2}/g and 1128 mg/g, respectively. Thermal decomposition of pure reedy grass leaves and H{sub 3}PO{sub 4}-impregnated reedy grass leaves have been investigated with thermogravimetric/mass spectroscopy (TG–MS) technique. It was found that the temperature and intensity of maximum evolution of H{sub 2}O and CO{sub 2} of H{sub 3}PO{sub 4}-impregnated reedy grass leaves were lower than that of pure reedy grass leaves. This implies that H{sub 3}PO{sub 4} as an activating reagent changed the thermal degradation of the reedy grass leaves, stabilized the cellulose structure, leading to a subsequent change in the evolution of porosity. The results of X-ray photoelectron spectroscopy and Fourier-infrared spectroscopy analysis indicate that the produced activated carbons have rich functional groups on surface.

  5. Structural, optical and electrical properties of Cu{sub 2}FeSnX{sub 4} (X = S, Se) thin films prepared by chemical spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Khadka, Dhruba B.; Kim, JunHo, E-mail: jhk@inu.ac.kr

    2015-07-25

    Highlights: • CFTS(Se) thin films have been synthesized by low-cost spray-based deposition. • The fabricated films were found to be of stannite structure and p-type conductivity. • Band gaps of CFTS and CFTSe thin films are 1.37 and 1.11 eV, respectively. - Abstract: We report on fabrication of polycrystalline Cu{sub 2}FeSnX{sub 4} (X = S, Se) thin films by chemical spray pyrolysis subsequent with post-sulfurization and selenization. The post-annealing of as-sprayed Cu{sub 2}FeSnS{sub 4} (CFTS) films in sulfur and selenium ambient demonstrated drastically improved surface texture as well as crystallinity. The crystal lattice parameters calculated from X-ray diffraction patterns for post-annealed films were found to be consistent with stannite structure. The fabricated Cu{sub 2}FeSnS{sub 4} (CFTS) and Cu{sub 2}FeSnSe{sub 4} (CFTSe) films showed p-type conductivity with carrier concentration in the range of 10{sup 21} cm{sup −3} and mobility ∼1–5 cm{sup 2} V{sup −1} s{sup −1}. The band gap energies of post-sulfurized CFTS and post-selenized CFTSe films were estimated to be ∼1.37 eV and ∼1.11 eV with an error of ±0.02 eV by UV–Vis absorption, respectively, which are promising for photovoltaic application.

  6. Photooxidation of different organic dyes (RB, MO, TB, and BG) using Fe(III)-doped TiO{sub 2} nanophotocatalyst prepared by novel chemical method

    Energy Technology Data Exchange (ETDEWEB)

    Ghorai, Tanmay K. [Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India); Department of Chemistry, Bajkul Milani Mahavidyalaya, Kismat Bajkul, Purba Medinipur 721655 (India)], E-mail: tanmay_ghorai@yahoo.co.in; Biswas, Soumya K. [Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India); Pramanik, Panchanan [Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India)], E-mail: pramanik@chem.iitkgp.ernet.in

    2008-09-15

    The nano-structured Fe(III)-doped TiO{sub 2} photocatalysts with anatase phase have been developed for the oxidation of non-biodegradable different organic dyes like methyl orange (MO), rhodamine B (RB), thymol blue (TB) and bromocresol green (BG) using UV-Hg-lamp. The different compositions of Fe{sub x}Ti{sub 1-x}O{sub 2} (x = 0.005, 0.01, 0.05, and 0.1) nanocatalysts synthesized by chemical method (CM), have been characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectra, specific surface area (BET), transmission electronic microscopy (TEM) analysis, XPS, ESR and zeta potential. From XRD analysis, the results indicate that all the compositions of Fe(III) doped in TiO{sub 2} catalysts gives only anatase phase not rutile phase. For complete degradation of all the solutions of the dyes (MO, RB, TB, and BG), the composition with x = 0.005 is more photoactive compared all other compositions of Fe{sub x}Ti{sub 1-x}O{sub 2}, and degussa P25. The decolorization rate of different dyes decreases as Fe(III) concentration in TiO{sub 2} increases. The energy band gap of Fe(III)-doped TiO{sub 2} is found to be 2.38 eV. The oxidation state of iron has been found to be 3+ from XPS and ESR show that Fe{sup 3+} is in low spin state.

  7. Preparation of 1-bromoheptacosane

    International Nuclear Information System (INIS)

    Hernandez, L.; Hernandez, A.; Gonzalez, J.C.

    1996-01-01

    Alkybromides are ones of the main organic precursors for fatty acids and alcohols labelling with Carbon 1-14. In this work the preparation of 1-bromoheptacosane by bromodescarboxylation of 1-octacosanoic acid is described. The synthesis yielded 80.5% of final product and more than 97% of chemical purity. Clean-up procedure modifications and spectral data bromoheptacosane are also reported

  8. Pilot-scale electron cyclotron resonance-metal organic chemical vapor deposition system for the preparation of large-area fluorine-doped SnO{sub 2} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Bup Ju [Department of Energy and Environmental Engineering, Shinhan University, 233-1, Sangpae-dong, Dongducheon, Gyeonggi-do 483-777 (Korea, Republic of); Hudaya, Chairul [Department of Electrical Engineering, Faculty of Engineering, Universitas Indonesia, Kampus Baru UI, Depok 16424 (Indonesia); Center for Energy Convergence, Green City Research Institute, Korea Institute of Science and Technology, Hwarangno 14 gil 5, Seoul 136-791 (Korea, Republic of); Department of Energy and Environmental Engineering, Korea University of Science and Technology, 176 Gajungro Yuseong-gu, Daejeon 305-350 (Korea, Republic of); Lee, Joong Kee, E-mail: leejk@kist.re.kr [Center for Energy Convergence, Green City Research Institute, Korea Institute of Science and Technology, Hwarangno 14 gil 5, Seoul 136-791 (Korea, Republic of); Department of Energy and Environmental Engineering, Korea University of Science and Technology, 176 Gajungro Yuseong-gu, Daejeon 305-350 (Korea, Republic of)

    2016-05-15

    The authors report the surface morphology, optical, electrical, thermal and humidity impacts, and electromagnetic interference properties of fluorine-doped tin oxide (SnO{sub 2}:F or “FTO”) thin films on a flexible polyethylene terephthalate (PET) substrate fabricated by a pilot-scale electron cyclotron resonance–metal organic chemical vapor deposition (PS ECR-MOCVD). The characteristics of large area FTO thin films were compared with a commercially available transparent conductive electrode made of tin-doped indium oxide (ITO), prepared with an identical film and PET thickness of 125 nm and 188 μm, respectively. The results revealed that the as-prepared FTO thin films exhibited comparable performances with the incumbent ITO films, including a high optical transmittance of 97% (substrate-subtracted), low electrical resistivity of about 5 × 10{sup −3} Ω cm, improved electrical and optical performances due to the external thermal and humidity impact, and an excellent shielding effectiveness of electromagnetic interference of nearly 2.3 dB. These excellent performances of the FTO thin films were strongly attributed to the design of the PS ECR-MOCVD, which enabled a uniform plasma environment resulting from a proper mixture of electromagnetic profiles and microwave power.

  9. Preparation and properties of calcium-silicate filled resins for dental restoration. Part I: chemical-physical characterization and apatite-forming ability.

    Science.gov (United States)

    Profeta, Andrea Corrado

    2014-11-01

    The aim of this study was to measure dimensional changes due to hygroscopic expansion and the bioactivity of two experimental methacrylate-based dental adhesives either incorporating Bioglass 45S5 (3-E&RA/BG) or MTA (3-E&RA/WMTA). 3-E&RA/BG, 3-E&RA/WMTA and a control filler-free resin blend (3-E&RA) were formulated from commercially available monomers. Water sorption (WS) and solubility (SL) behaviour were evaluated by weighing material disks at noted intervals; the relationship between degree of hydration and the glass transition temperature (Tg) was investigated by using differential scanning calorimetry (DSC). In vitro apatite-forming ability as a function of soaking time in phosphate-containing solutions was also determined. Kruskal-Wallis analysis of variance (ANOVA) was used to evaluate differences between groups for maximum WS, SL, net water uptake and the percentage change in Tg values. Post-ANOVA pair-wise comparisons were conducted using Mann-Whitney-U tests. 3-E&RA/BG and 3-E&RA/WMTA exhibited values of maximum WS and net water uptake that were significantly higher when compared to 3-E&RA. However, no statistically significant differences were observed in terms of SL between all the adhesives. The addition of the Bioglass 45S5 and MTA to the 3-E&RA showed no reduction of the Tg after 60 days of storage in deionized water. ATR Fourier Transform Infrared Spectroscopy (ATR-FTIR) of the filled resin disks soaked in DPBS for 60 days showed the presence of carbonate ions in different chemical phases. Dentine bonding agents comprising calcium-silicates are not inert materials in a simulated oral environment and apatite formation may occur in the intra-oral conditions. A bioactive dental material which forms apatite on the surface would have several benefits including closure of gaps forming at the resin-dentine interface and potentially better bond strength over time (less degradation of bond).

  10. Recommended inorganic chemicals for calibration

    International Nuclear Information System (INIS)

    Moody, J.R.; Greenberg, R.R.; Pratt, K.W.; Rains, T.C.

    1988-01-01

    All analytical techniques depend on the use of calibration chemicals to relate analyte concentration to an instrumental parameter. A fundamental component in the preparation of calibration solutions is the weighing of a pure chemical or metal before preparing a solution standard. The analyst must be assured that the purity, stoichiometry, and assay of the chemical are known. These terms have different meanings, and each has an important influence. This report is intended to assist the analyst in the selection and use of chemical standards for instrumental calibration. Purity, stoichiometry, and preparation of solutions for different purposes are discussed, and a critical evaluation of the best materials available for each element is presented for use in preparing solutions or calibration standards. Information on the chemical form, source, purity, drying, and appropriate precautions is given. In some cases, multiple sources or chemical forms are available. Certain radioactive elements, the transuranic elements, and the noble gases are not considered

  11. Preparation of hydrogenated amorphous carbon films using a microsecond-pulsed DC capacitive-coupled plasma chemical vapor deposition system operated at high frequency up to 400 kHz

    Science.gov (United States)

    Mamun, Md Abdullah Al; Furuta, Hiroshi; Hatta, Akimitsu

    2018-06-01

    Hydrogenated amorphous carbon (a-C:H) films are deposited on silicon (Si) substrates using a high-repetition microsecond-pulsed DC plasma chemical vapor deposition (CVD) system from acetylene (C2H2) at a gas pressure of 15 Pa inside a custom-made vacuum chamber. The plasma discharge characteristics, hydrocarbon species, and the microstructure of the resulting films are examined at various pulse repetition rates from 50 to 400 kHz and a fixed duty cycle of 50%. The optical emission spectra confirmed the increase in electron excitation energy from 1.09 to 1.82 eV and the decrease in the intensity ratio of CH/C2 from 1.04 to 0.75 with increasing pulse frequency, indicating the enhanced electron impact dissociation of C2H2 gas. With increasing pulse frequency, the deposition rate gradually increased, reaching a maximum rate of 60 nm/min at 200 kHz, after which a progressive decrease was noted, whereas the deposition area was almost uniform for all the prepared films. Clear trends of increasing sp3 content (amorphization) and decreasing hydrogen (H) content in the films were observed as the pulse repetition rate increased, while most of the hydrogen atoms bonded to carbon atoms by sp3 hybridization rather than by sp2 hybridization.

  12. An X-band Co2+ EPR study of Zn1-xCoxO (x=0.005-0.1) nanoparticles prepared by chemical hydrolysis methods using diethylene glycol and denaturated alcohol at 5 K

    Science.gov (United States)

    Misra, Sushil K.; Andronenko, S. I.; Srinivasa Rao, S.; Chess, Jordan; Punnoose, A.

    2015-11-01

    EPR investigations on two types of dilute magnetic semiconductor (DMS) ZnO nanoparticles doped with 0.5-10% Co2+ ions, prepared by two chemical hydrolysis methods, using: (i) diethylene glycol ((CH2CH2OH)2O) (NC-rod-like samples), and (ii) denatured ethanol (CH3CH2OH) solutions (QC-spherical samples), were carried out at X-band (9.5 GHz) at 5 K. The analysis of EPR data for NC samples revealed the presence of several types of EPR lines: (i) two types, intense and weak, of high-spin Co2+ ions in the samples with Co concentration >0.5%; (ii) surface oxygen vacancies, and (iii) a ferromagnetic resonance (FMR) line. QC samples exhibit an intense FMR line and an EPR line due to high-spin Co2+ ions. FMR line is more intense, than the corresponding line exhibited by NC samples. These EPR spectra varied for sample with different doping concentrations. The magnetic states of these samples as revealed by EPR spectra, as well as the origin of ferromagnetism DMS samples are discussed.

  13. Structures and electrical properties of Mn- and Co-doped lead-free ferroelectric K0.5Na0.5NbO3 films prepared by a chemical solution deposition method

    International Nuclear Information System (INIS)

    Wang, Lingyan; Ren, Wei; Goh, Phoi Chin; Yao, Kui; Shi, Peng; Wu, Xiaoqing; Yao, Xi

    2013-01-01

    The un-doped, 2 mol% Mn- and 2 mol% Co-doped K 0.5 Na 0.5 NbO 3 (KNN) films were prepared by a chemical solution deposition method. The crystalline phase and surface morphologies of KNN films hardly changed after Mn- and Co-doping. X-ray photoelectron spectrocopy analysis indicates that the introduction of both Mn and Co promoted the formation of KNN perovskite structure, and the most Mn 2+ and Co 2+ ions were oxidized into high-valence ions during thermal process. As a result, the leakage current density of the KNN films was decreased and the electrical properties were enhanced after the doping. - Highlights: • The leakage current density of K 0.5 Na 0.5 NbO 3 (KNN) films decreased after doping • The introduction of dopant promoted the formation of KNN perovskite structure • A portion of introduced doping ions became high-valent after heat-treatment

  14. Nanoscale Ferroelectric Switchable Polarization and Leakage Current Behavior in (Ba0.50Sr0.50(Ti0.80Sn0.20O3 Thin Films Prepared Using Chemical Solution Deposition

    Directory of Open Access Journals (Sweden)

    Venkata Sreenivas Puli

    2015-01-01

    Full Text Available Nanoscale switchable ferroelectric (Ba0.50Sr0.50(Ti0.80Sn0.20O3-BSTS polycrystalline thin films with a perovskite structure were prepared on Pt/TiOx/SiO2/Si substrate by chemical solution deposition. X-ray diffraction (XRD spectra indicate that a cubic perovskite crystalline structure and Raman spectra revealed that a tetragonal perovskite crystalline structure is present in the thin films. Sr2+ and Sn4+ cosubstituted film exhibited the lowest leakage current density. Piezoresponse Force Microscopy (PFM technique has been employed to acquire out-of-plane (OPP piezoresponse images and local piezoelectric hysteresis loop in polycrystalline BSTS films. PFM phase and amplitude images reveal nanoscale ferroelectric switching behavior at room temperature. Square patterns with dark and bright contrasts were written by local poling and reversible nature of the piezoresponse behavior was established. Local piezoelectric butterfly amplitude and phase hysteresis loops display ferroelectric nature at nanoscale level. The significance of this paper is to present ferroelectric/piezoelectric nature in present BSTS films at nanoscale level and corroborating ferroelectric behavior by utilizing Raman spectroscopy. Thus, further optimizing physical and electrical properties, BSTS films might be useful for practical applications which include nonvolatile ferroelectric memories, data-storage media, piezoelectric actuators, and electric energy storage capacitors.

  15. The Preparation of Graphene

    Institute of Scientific and Technical Information of China (English)

    Chen Yanyan

    2015-01-01

    Graphene has unique structure and possesses excellent physical and chemical properties, and it has received a great deal of attention in related research fields. The quality, quantity and application of graphene are related to its preparation methods. At present the bottleneck of graphene research is that both high-quality and large quantity of graphene could not be obtained simultaneously and the reason is that the basic mechanism of graphene formation has mot been wel understood.

  16. Personnel Preparation.

    Science.gov (United States)

    Fair, George, Ed.; Stodden, Robert, Ed.

    1981-01-01

    Three articles comprise a section on personnel preparation in vocational education. Articles deal with two inservice programs in career/vocational education for the handicapped and a project to train paraprofessionals to assist special educators in vocational education. (CL)

  17. Chemical Emergencies

    Science.gov (United States)

    When a hazardous chemical has been released, it may harm people's health. Chemical releases can be unintentional, as in the case of an ... the case of a terrorist attack with a chemical weapon. Some hazardous chemicals have been developed by ...

  18. Characterization and study of reduction and sulfurization processing in phase transition from molybdenum oxide (MoO{sub 2}) to molybdenum disulfide (MoS{sub 2}) chalcogenide semiconductor nanoparticles prepared by one-stage chemical reduction method

    Energy Technology Data Exchange (ETDEWEB)

    Shomalian, K.; Bagheri-Mohagheghi, M.M.; Ardyanian, M. [Damghan University, School of Physics, Damghan (Iran, Islamic Republic of)

    2017-01-15

    In this research, molybdenum disulfide (MoS{sub 2}) nanoparticles were prepared by chemical reduction method using MoO{sub 3} and thiourea as a precursor. The physical properties of the synthesized MoO{sub 2}-MoS{sub 2} nanoparticles annealed at different temperatures of 200, 300, 750 C have been investigated, before and after exposure to sulfur vapor. The nanostructure of nanoparticles has been characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM) analyses and UV-Vis spectrophotometer. The X-ray diffraction analysis showed the formation of MoS{sub 2} single phase at annealing temperature of 750 C in the presence of sulfur vapor. The Raman spectrum of the nanoparticles revealed that the formation of MoS{sub 2} at 750 C after annealing in sulfur vapor. The values of band gap were obtained in the range of 3.64-3.17 eV and 3.47-1.95 eV for MoS{sub 2} nanoparticles before and after exposure to sulfur vapor, respectively. According to SEM images, the grain size decreases with increasing annealing temperature up to 750 C. Also, nanoplate-nanoparticles of MoS{sub 2} are formed at annealing temperature of 200-750 C. The TEM images of MoS{sub 2} nanoparticles at T{sub a} = 750 C confirm that the nanoparticles have a homogeneous distribution with a hexagonal structure. The FTIR spectra of the MoS{sub 2} nanoparticles showed the peaks at about 467 cm {sup -1} belong to the characteristic bands of Mo-S. (orig.)

  19. Sample preparation

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Sample preparation prior to HPLC analysis is certainly one of the most important steps to consider in trace or ultratrace analysis. For many years scientists have tried to simplify the sample preparation process. It is rarely possible to inject a neat liquid sample or a sample where preparation may not be any more complex than dissolution of the sample in a given solvent. The last process alone can remove insoluble materials, which is especially helpful with the samples in complex matrices if other interactions do not affect extraction. Here, it is very likely a large number of components will not dissolve and are, therefore, eliminated by a simple filtration process. In most cases, the process of sample preparation is not as simple as dissolution of the component interest. At times, enrichment is necessary, that is, the component of interest is present in very large volume or mass of material. It needs to be concentrated in some manner so a small volume of the concentrated or enriched sample can be injected into HPLC. 88 refs

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

    Indian Academy of Sciences (India)

    The surface area and particle size of HAP powder prepared by chemical precipitation route, were also ... chemical precipitation method (Jarcho 1978). The powders .... den snail shell, Helix aspersa, was done by taking tris-HCl buffer solution.

  1. Partial chemical characterization of antigenic preparations of chromoblastomycosis agents Caracterização química parcial de preparações antigênicas de agentes da cromoblastomicose

    Directory of Open Access Journals (Sweden)

    Tania Fraga BARROS

    1999-11-01

    Full Text Available Antigenic preparations (saline, methylic, metabolic and exoantigens of four agents of chromoblastomycosis, Fonsecaea pedrosoi, Phialophora verrucosa, Cladophialophora (Cladosporium carrionii and Rhinocladiella aquaspersa were obtained. Partial chemical characterization of these antigenic preparations was obtained by determination of the levels of total lipids, protein, and carbohydrates, and identification of the main sterols and carbohydrates. Methylic antigens presented the highest lipid contents, whereas metabolic antigens showed the highest carbohydrate content. Total lipid, protein, and carbohydrate levels were in the range of 2.33 to 2.00mg/ml, 0.04 to 0.02 mg/ml and 0.10 to 0.02 mg/ml, respectively, in the methylic antigens and in the range of 0.53 to 0.18mg/ml, 0.44 to 0.26mg/ml, and 1.82 to 1.02 mg/ml, respectively, in saline antigens. Total lipid, protein, and carbohydrate contents were in the range of 0.55 to 0.20mg/ml, 0.69 to 0.57mg/ml and 10.73 to 5.93mg/ml, respectively, in the metabolic antigens, and in the range of 0.55 to 0.15mg/ml, 0.62 to 0.20mg/ml and 3.55 to 0.42mg/ml, respectively, in the exoantigens. Phospholipids were not detected in the preparations. Saline and metabolic antigens and exoantigens presented hexose and the methylic antigen revealed additional pentose units in their composition. The UV light absorption spectra of the sterols revealed squalene and an ergosterol fraction in the antigens. The characterization of these antigenic preparations may be useful for serological evaluation of patients of chromoblastomycosis.Preparações antigênicas (antígenos salinos, metílicos, metabólicos e exoantígenos de quatro agentes da cromoblastomicose, Fonsecaea pedrosoi, Phialophora verrucosa, Cladophialophora (Cladosporium carrionii e Rhinocladiella aquaspersa foram obtidos e foi determinada a caracterização química parcial dos mesmos. Os antígenos metílicos apresentaram os maiores teores de lípides enquanto os

  2. Precipitation and ultimate pH effect on chemical and gelation properties of protein prepared by isoelectric solubilization/precipitation process from pale, soft, exudative (PSE)-like chicken breast meat1.

    Science.gov (United States)

    Zhao, X; Xing, T; Chen, X; Han, M-Y; Li, X; Xu, X-L; Zhou, G-H

    2017-05-01

    Pale, soft, exudative (PSE)-like chicken breast is considered deteriorated raw material in the poultry meat industry that has inferior processing ability. The chemical and gelation properties of PSE-like chicken breast meat paste were studied. These pastes were prepared by the pH adjustment method and protein isolation using the isoelectric solubilization/precipitation (ISP) process from PSE-like chicken meat. The ISP-isolated samples were solubilized at pH 11.0 and recovered at pH 5.5 and 6.2. The ultimate pH of the ISP-isolated protein and meat paste was adjusted to 6.2 and 7.0. The ultimate pH in this article referred to the final pH of the extracted protein and meat paste. Higher reactive sulfhydryl content and surface hydrophobicity were found in the precipitation at pH 6.2 than at pH 5.5. However, various ultimate pH values showed no significant influence on the surface hydrophobicity. The hardness of gel, as measured by textural profile analysis, was improved using 6.2 as the precipitation pH compared with pH 5.5. The viscoelastic modulus (G΄) of gel pastes prior to the thermal gelation was higher with ISP treatment. However, lower G΄ was seen after thermal gelation compared with the control. Dynamic rheological measurement demonstrated a different gel-forming mechanism for protein precipitated at pH values of 5.5 and 6.2 compared with the meat paste. The cooking loss showed that the recovered protein failed to form a gel with good water-retention capacity unless the ultimate pH was adjusted to 7.0. Gels made from protein extracted by the ISP method had higher yellowness and lower redness values, probably due to protein denaturation. Precipitation at pH 6.2 formed a harder gel with lower water-retention ability than that at pH 5.5, and this result was possibly due to higher surface hydrophobicity and S-S bridge formation. Overall, network characteristics of ISP-treated protein gels were strongly dependent on precipitation pH and ultimate pH. © 2016

  3. Chemical hygiene plan

    International Nuclear Information System (INIS)

    1994-09-01

    This plan was written to administer and monitor safety measures and chemical hygiene principles in the TAC Uranium Mill Tailing Remedial Action Project sample preparation facility in Albuquerque, New Mexico. It applies to toxic and/or hazardous materials to radioactive materials

  4. Radioprotective preparation

    International Nuclear Information System (INIS)

    Stefanova, D.; Frattadochi, A.; Gattavecchia, E.; Ferri, E.; Tonnelli, D.

    1988-01-01

    The invention is intended for radiation injuries prophylaxis in mammals. It has an well expressed radioprotective effect against acute gamma irradiation on cellular level as well as a prolonged action when applied up to 48 hours before the acute irradiation. The preparation is a coprecipitate of the natural tripeptide glutathione (reduced form) and polyvinyl pyrrolidone (pvp) in ratio 30-60/70-40. It is obtained by incubation method with subsequent lyophilization from water solution of the initial components. The molecular mass of the pvp is 20 till 360.10 3 . 2 claims

  5. Target preparation

    International Nuclear Information System (INIS)

    Hinn, G.M.

    1984-01-01

    A few of the more interesting of the 210 targets prepared in the Laboratory last year are listed. In addition the author continues to use powdered silver mixed with /sup 9,10/BeO to produce sources for accelerator radio dating of Alaskan and South Polar snow. Currently, he is trying to increase production by multiple sample processing. Also the author routinely makes 3 μg/cm 2 cracked slacked carbon stripper foils and is continuing research with some degree of success in making enriched 28 Si targets starting with the oxide

  6. Ultra-high performance liquid chromatography coupled with photo-diode array and quadrupole/time-of-flight mass spectrometry based chemical profiling approach to evaluate the influence of preparation methods on the holistic quality of Qiong-Yu-Gao, a traditional complex herbal medicine.

    Science.gov (United States)

    Xu, Jin-Di; Mao, Qian; Shen, Hong; Zhu, Ling-Ying; Li, Song-Lin; Yan, Ru

    2013-08-23

    Qiong-Yu-Gao (QYG), consisting of Rehmanniae Radix (RR), Poriae (PO) and Ginseng Radix (GR), is a commonly used tonic traditional complex herbal medicine (CHM). So far, three different methods have been documented for preparation of QYG, i.e. method 1 (M1): mixing powders of GR and PO with decoction of RR; method 2 (M2): combining the decoction of RR and PO with the decoction of GR; method 3 (M3): decocting the mixture of RR, GR and PO. In present study, an ultra-high performance liquid chromatography coupled with photo-diode array and quadrupole/time-of-flight mass spectrometry (UHPLC-PDA-QTOF-MS/MS) based chemical profiling approach was developed to investigate the influence of the three preparation methods on the holistic quality of QYG. All detected peaks were unambiguously identified by comparing UV spectra, accurate mass data/characteristic mass fragments and retention times with those of reference compounds, and/or tentatively assigned by matching empirical molecular formula with that of known compounds, and/or elucidating quasi-molecular ions and fragment ions referring to information available in literature. A total of 103 components, mainly belonging to ginsenosides, phenethylalcohol glycosides, iridoid glycosides and triterpenoid acids, were identified, of which 5 degraded ginsenosides were putatively determined to be newly generated during preparation procedures of QYG samples. Triterpenoid acids and malonyl-ginsenosides were detected only in M1 samples, while degraded ginsenosides were merely detectable in M2/M3 samples. The possible reasons for the difference among chemical profiles of QYG samples prepared with three methods were also discussed. It could be concluded that preparation method do significantly affect the holistic quality of QYG. The influence of the altered chemical profiles on the bioactivity of QYG needs further investigation. The present study demonstrated that UHPLC-PDA-QTOF-MS/MS based chemical profiling approach is efficient and

  7. Chemical Peels

    Science.gov (United States)

    ... for Every Season How to Choose the Best Skin Care Products In This Section Dermatologic Surgery What is dermatologic ... for Every Season How to Choose the Best Skin Care Products Chemical Peels Uses for Chemical Peels Learn more ...

  8. Chemical Oscillations

    Indian Academy of Sciences (India)

    IMTECH),. Chandigarh. Praveen Kumar is pursuing his PhD in chemical dynamics at. Panjab University,. Chandigarh. Keywords. Chemical oscillations, autoca-. talYSis, Lotka-Volterra model, bistability, hysteresis, Briggs-. Rauscher reaction.

  9. Chemical ecotoxicology

    International Nuclear Information System (INIS)

    Paasivirta, J.

    1991-01-01

    This book discusses risk assessment, chemical cycles, structure-activity relations, organohalogens, oil residues, mercury, sampling and analysis of trace chemicals, and emissions from the forestry industry. Topics include: Cycles of chemicals in the environment. Rick assessment and management, strucuture and toxicity, sampling and analysis of trace chemicals in environment, interpretation of the environmental analysis results, mercury in the environment, organohalogen compounds in the environment, emissions from forestry industry, oil residues in the environment: oil spills in the marine environment

  10. Chemical sensor

    Science.gov (United States)

    Rauh, R. David (Inventor)

    1990-01-01

    A sensor for detecting a chemical substance includes an insertion element having a structure which enables insertion of the chemical substance with a resulting change in the bulk electrical characteristics of the insertion element under conditions sufficient to permit effective insertion; the change in the bulk electrical characteristics of the insertion element is detected as an indication of the presence of the chemical substance.

  11. [Chemical weapons and chemical terrorism].

    Science.gov (United States)

    Nakamura, Katsumi

    2005-10-01

    Chemical Weapons are kind of Weapons of Mass Destruction (WMD). They were used large quantities in WWI. Historically, large quantities usage like WWI was not recorded, but small usage has appeared now and then. Chemical weapons are so called "Nuclear weapon for poor countrys" because it's very easy to produce/possession being possible. They are categorized (1) Nerve Agents, (2) Blister Agents, (3) Cyanide (blood) Agents, (4) Pulmonary Agents, (5) Incapacitating Agents (6) Tear Agents from the viewpoint of human body interaction. In 1997 the Chemical Weapons Convention has taken effect. It prohibits chemical weapons development/production, and Organization for the Prohibition of Chemical Weapons (OPCW) verification regime contributes to the chemical weapons disposal. But possibility of possession/use of weapons of mass destruction by terrorist group represented in one by Matsumoto and Tokyo Subway Sarin Attack, So new chemical terrorism countermeasures are necessary.

  12. Ultrasound in chemical processes

    International Nuclear Information System (INIS)

    Baig, S.; Farooq, R.; Malik, A.H.

    2009-01-01

    The use of ultrasound to promote chemical reactions or sono chemistry is a field of chemistry which involves the process of acoustic cavitations i.e. the collapse of microscopic bubbles in liquid. There are two essential components for the application of sono chemistry, a liquid medium and a source of high-energy vibrations. The liquid medium is necessary because sono chemistry is driven by acoustic cavitations that can only occur in liquids. The source of the vibrational energy is the transducer. The chemical effects of ultrasound include the enhancement of reaction rates at ambient temperatures and striking advancements in stoichiometric and catalytic reactions In some cases, ultrasonic irradiation can increase reactivities by nearly million fold. The ultrasound has large number of applications not only in emending old chemical processes but also in developing new synthetic strategies. Ultrasound enhances all chemical and physical processes e.g., crystallization, vitamin synthesis, preparation of catalysts, dissolution of chemicals, organometallic reactions, electrochemical processes, etc. High-power ultrasonics is a new powerful technology that is not only safe and environmentally friendly in its application but is also efficient and economical. It can be applied to existing processes to eliminate the need for chemicals and/or heat application in a variety of industrial processes. (author)

  13. Hazardous Chemicals

    Centers for Disease Control (CDC) Podcasts

    Chemicals are a part of our daily lives, providing many products and modern conveniences. With more than three decades of experience, The Centers for Disease Control and Prevention (CDC) has been in the forefront of efforts to protect and assess people's exposure to environmental and hazardous chemicals. This report provides information about hazardous chemicals and useful tips on how to protect you and your family from harmful exposure.

  14. Alarms, Chemical

    Science.gov (United States)

    cited in applicable qualitative materiel requirements, small development requirements, technical characteristics, and other requirements and documentation that pertain to automatic chemical agent alarms.

  15. Chemical oceanography

    National Research Council Canada - National Science Library

    Millero, F.J

    1996-01-01

    Chemical Oceanography presents a comprehensive examination of the chemistry of oceans through discussions of such topics as descriptive physical oceanography, the composition of seawater and the major...

  16. Chemical Emergencies - Multiple Languages

    Science.gov (United States)

    ... Chemical Emergencies - bosanski (Bosnian) PDF Chemical Emergencies - English MP3 Chemical Emergencies - bosanski (Bosnian) MP3 Chemical Emergencies - English MP4 Chemical Emergencies - bosanski (Bosnian) ...

  17. Spectroscopic ellipsometry characterization of nano-crystalline diamondfilms prepared at various substrate temperatures and pulsed plasma frequencies using microwave plasma enhanced chemical vapor deposition apparatus with linear antenna delivery

    Czech Academy of Sciences Publication Activity Database

    Mistrík, J.; Janíček, P.; Taylor, Andrew; Fendrych, František; Fekete, Ladislav; Jäger, Aleš; Nesládek, M.

    2014-01-01

    Roč. 571, č. 1 (2014), s. 230-237 ISSN 0040-6090 R&D Projects: GA ČR GA13-31783S; GA MŠk(CZ) LM2011026 Grant - others: COST Nano TP(XE) MP0901; OP VK(XE) CZ.1.07/2.3.00/20.0306 Institutional support: RVO:68378271 Keywords : nanocrystalline diamond * thin films * microwave plasma-enhanced chemical vapor deposition * pulsed plasma * low deposition temperature Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.759, year: 2014

  18. Effect of annealing temperatures on the electrical conductivity and dielectric properties of Ni1.5Fe1.5O4 spinel ferrite prepared by chemical reaction at different pH values

    Science.gov (United States)

    Aneesh Kumar, K. S.; Bhowmik, R. N.

    2017-12-01

    The electrical conductivity and dielectric properties of Ni1.5Fe1.5O4 ferrite has been controlled by varying the annealing temperature of the chemical routed samples. The frequency activated conductivity obeyed Jonscher’s power law and universal scaling suggested semiconductor nature. An unusual metal like state has been revealed in the measurement temperature scale in between two semiconductor states with different activation energy. The metal like state has been affected by thermal annealing of the material. The analysis of electrical impedance and modulus spectra has confirmed non-Debye dielectric relaxation with contributions from grains and grain boundaries. The dielectric relaxation process is thermally activated in terms of measurement temperature and annealing temperature of the samples. The hole hopping process, due to presence of Ni3+ ions in the present Ni rich ferrite, played a significant role in determining the thermal activated conduction mechanism. This work has successfully applied the technique of a combined variation of annealing temperature and pH value during chemical reaction for tuning electrical parameters in a wide range; for example dc limit of conductivity ~10-4-10-12 S cm-1, and unusually high activation energy ~0.17-1.36 eV.

  19. A New Paradigm for Chemical Engineering?

    DEFF Research Database (Denmark)

    Gani, Rafiqul

    evidence of this change comes from the jobs taken by graduating chemical engineering professionals in North America, Europe, and some of the Asian countries. In terms of where the graduating chemical engineers are going to work, a clear shift from the commodity chemical industry to the product oriented...... businesses has been observed. There is an increasing trend within the chemical industry to focus on products and the sustainable processes that can make them. Do these changes point to a paradigm shift in chemical engineering as a discipline? Historically, two previous paradigm shifts in chemical engineering...... corresponded to major shifts in chemical engineering as a discipline, which affected not only the education of chemical engineers, but also the development of chemical engineering as a discipline. Has the time come for a new paradigm shift that will prepare the current and future chemical engineering graduates...

  20. Preparing for Surgery

    Science.gov (United States)

    ... Events Advocacy For Patients About ACOG Preparing for Surgery Home For Patients Search FAQs Preparing for Surgery ... Surgery FAQ080, August 2011 PDF Format Preparing for Surgery Gynecologic Problems What is the difference between outpatient ...

  1. Hazardous Chemicals

    Centers for Disease Control (CDC) Podcasts

    2007-04-10

    Chemicals are a part of our daily lives, providing many products and modern conveniences. With more than three decades of experience, The Centers for Disease Control and Prevention (CDC) has been in the forefront of efforts to protect and assess people's exposure to environmental and hazardous chemicals. This report provides information about hazardous chemicals and useful tips on how to protect you and your family from harmful exposure.  Created: 4/10/2007 by CDC National Center for Environmental Health.   Date Released: 4/13/2007.

  2. THE USE OF CHEMICALS AS PLANT REGULATORS. AGRICULTURAL CHEMICALS TECHNOLOGY, NUMBER 8.

    Science.gov (United States)

    Ohio State Univ., Columbus. Center for Vocational and Technical Education.

    ONE OF A SERIES DESIGNED TO ASSIST TEACHERS IN PREPARING POST-SECONDARY STUDENTS FOR AGRICULTURAL CHEMICAL OCCUPATIONS, THIS MODULE IS SPECIFICALLY CONCERNED WITH CHEMICALS AS PLANT REGULATORS. IT WAS DEVELOPED BY A NATIONAL TASK FORCE ON THE BASIS OF DATA FROM STATE STUDIES. SECTIONS INCLUDE -- (1) CHEMICALS AS MODIFIERS OF PLANT GROWTH, (2)…

  3. Criterious preparation and characterization of earthworm-composts in view of animal waste recycling. Part I. Correlation between chemical, thermal and FTIR spectroscopic analyses of four humic acids from earthworm-composted animal manure

    Directory of Open Access Journals (Sweden)

    Mangrich Antonio S.

    2000-01-01

    Full Text Available Humic acids (HA were extracted from sheep (SH, cow (CO, goat (GO and rabbit (RA manures which were vermicomposted with the earthworm Eisenia foetida. HA DSC curves showed well-defined thermal events indicative of intramolecular bonds (300 ºC and intermolecular organo-mineral linkages (500 ºC. All samples showed high nitrogen contents (from peptide chains and probably N-heterocycles and aromatic and/or unsaturated aliphatic conjugated structures, as well as a low carboxylic functionality content. The SH-HA was the most similar to a medium soil HA and the RA-HA being the least similar. The results show that it is possible to prepare distinct worm-composts to solve specific problems of degraded soils.

  4. [Sample preparation and bioanalysis in mass spectrometry].

    Science.gov (United States)

    Bourgogne, Emmanuel; Wagner, Michel

    2015-01-01

    The quantitative analysis of compounds of clinical interest of low molecular weight (sample preparation. Sample preparation is a crucial part of chemical/biological analysis and in a sense is considered the bottleneck of the whole analytical process. The main objectives of sample preparation are the removal of potential interferences, analyte preconcentration, and converting (if needed) the analyte into a more suitable form for detection or separation. Without chromatographic separation, endogenous compounds, co-eluted products may affect a quantitative method in mass spectrometry performance. This work focuses on three distinct parts. First, quantitative bioanalysis will be defined, different matrices and sample preparation techniques currently used in bioanalysis by mass spectrometry of/for small molecules of clinical interest in biological fluids. In a second step the goals of sample preparation will be described. Finally, in a third step, sample preparation strategies will be made either directly ("dilute and shoot") or after precipitation.

  5. Chemical Peel

    Science.gov (United States)

    ... your expectations. Talk with your doctor about your motivations and expectations, as well as the potential risks. ... the sun permanently to prevent changes in skin color. Keep in mind that chemical peel results might ...

  6. Chemical carcinogens

    National Research Council Canada - National Science Library

    Searle, Charles E

    1976-01-01

    Cancer causing agents are now known to exist throughout the environment-in polluted air and tobacco smoke, in various plants and foods, and in many chemicals that are used in industry and laboratories...

  7. chemical and mineralogical characterization of lateritic iron ore

    African Journals Online (AJOL)

    DJFLEX

    2010-04-22

    Apr 22, 2010 ... The laterite iron ore deposit at Auchi, Edo State, Nigeria was studied chemically and mineralogically. The results of the chemical ... SAMPLE PREPARATION. The samples .... 2µm) and were subjected to X-ray diffraction using.

  8. Chemical Research of Sir Prafulla Chandra Ray

    Indian Academy of Sciences (India)

    Calcutta University as the first Palit Professor of Chemistry in the year 1916 ... He and his students prepared ... Indian Chemical Society was born) were published in the Journal .... to develop the chemistry of alkylammonium nitrites. He pre-.

  9. Preparation of ultrafine iron particles by chemical vapor deposition of Fe(CO) sub 5. Fe(CO) sub 5 wo gebryo to suru kiso kagaku hanno ni yoru tetsuchobiryushi no seisei

    Energy Technology Data Exchange (ETDEWEB)

    Sawada, Y; Kageyama, Y. (Mitsubishi Petrochemical Co. Ltd., Tokyo (Japan)): Iwata, M. (Nagoya University, Nagoya (Japan). Faculty of Engineering)

    1991-11-10

    An ultrafine iron particle preparing process was developed, which wses gaseous phase pyrolysis in magnetic field of iron pentacarbonyl, Fe(CO){sub 5}, based on the fact that Fe(CO){sub 5} has peculiar characters that its boiling point is as low as 103{degree}C, and starts decomposing in a low temperature zone of 100{degree}C or lower. Vaporizing and introducing into a reactor an fe(CO){sub 5}, andPyrolyzing it at 200-600{degree}C while being diluted with nitrogen and applied with a magnetic field produced uitrafine iron particles of a necklace-like chain comprisinh primary particles having diameter of 15 to 25 nm with 10 to 40 of them linked in a straight chain. It was found that the specific surface area is 30-50 m{sup 2}/g, with the diameter converted from the specific surface area being relatively close to the average diameter obtained from TEM photograph, and that the particle has few pores. Magnetically the iron powder has a coercivity of 123-131 KA/m and a specific saturation magnetization of 120-140 Am{sup 2}/kg, and is expected to be applied as a high density magnetic recording medium. 5 refs.,8 figs., 3 tabs.

  10. Chemical sensors

    International Nuclear Information System (INIS)

    Hubbard, C.W.; Gordon, R.L.

    1987-05-01

    The revolution in analytical chemistry promised by recent developments in the field of chemical sensors has potential for significant positive impact on both research and production activities conducted by and for the Department of Energy. Analyses which were, in the past, performed only with a roomful of expensive equipment can now be performed with miniature solid-state electronic devices or small optical probes. Progress in the development of chemical sensors has been rapid, and the field is currently growing at a great rate. In accordance, Pacific Northwest Laboratory initiated a survey of recent literature so that contributors to active programs in research on analytical methods could be made aware of principles and applications of this new technology. This report presents the results of that survey. The sensors discussed here are divided into three types: micro solid-state devices, optical sensors, and piezoelectric crystal devices. The report is divided into three corresponding sections. The first section, ''Micro Solid-State Devices,'' discusses the design, operation, and application of electronic sensors that are produced in much the same way as standard solid-state electronic devices. The second section, ''Optrodes,'' covers the design and operation of chemical sensors that use fiber optics to detect chemically induced changes in optical properties. The final section, ''Piezoelectric Crystal Detectors,'' discusses two types of chemical sensors that depend on the changes in the properties of an oscillating piezoelectric crystal to detect the presence of certain materials. Advantages and disadvantages of each type of sensor are summarized in each section

  11. Characterization of photoluminescent (Y{sub 1{minus}x}Eu{sub x}){sub 2}O{sub 3} thin-films prepared by metallorganic chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    McKittrick, J.; Bacalski, C.F.; Hirata, G.A. [Univ. of California, San Diego, La Jolla, CA (United States); Hubbard, K.M.; Pattillo, S.G.; Salazar, K.V.; Trkula, M. [Los Alamos National Lab., NM (United States). Materials Science and Technology Div.

    1998-12-01

    Europium doped yttrium oxide, (Y{sub 1{minus}x}Eu{sub x}){sub 2}O{sub 3}, thin-films were deposited on silicon and sapphire substrates by metallorganic chemical vapor deposition (MOCVD). The films were grown in a MOCVD chamber reacting yttrium and europium tris(2,2,6,6-tetramethyl-3,5,-heptanedionates) precursors in an oxygen atmosphere at low pressures (5 Torr) and low substrate temperatures (500--700 C). The films deposited at 500 C were flat and composed of nanocrystalline regions of cubic Y{sub 2}O{sub 3}, grown in a textured [100] or [110] orientation to the substrate surface. Films deposited at 600 C developed from the flat, nanocrystalline morphology into a plate-like growth morphology oriented in the [111] with increasing deposition time. Monoclinic Y{sub 2}O{sub 3}:Eu{sup 3+} was observed in x-ray diffraction for deposition temperatures {ge}600 C on both (111) Si and (001) sapphire substrates. This was also confirmed by the photoluminescent emission spectra.

  12. Microfabrication, separations, and detection by mass spectrometry on ultrathin-layer chromatography plates prepared via the low-pressure chemical vapor deposition of silicon nitride onto carbon nanotube templates.

    Science.gov (United States)

    Kanyal, Supriya S; Häbe, Tim T; Cushman, Cody V; Dhunna, Manan; Roychowdhury, Tuhin; Farnsworth, Paul B; Morlock, Gertrud E; Linford, Matthew R

    2015-07-24

    Microfabrication of ultrathin-layer chromatography (UTLC) plates via conformal deposition of silicon nitride by low-pressure chemical vapor deposition onto patterned carbon nanotube (CNT) scaffolds was demonstrated. After removal of the CNTs and hydroxylation, the resulting UTLC phase showed no expansion or distortion of their microfeatures and the absence/reduction of remaining nitrogenic species. Developing time of a mixture of lipophilic dyes on this UTLC plates was 86% shorter than on high-performance thin-layer chromatography (HPTLC) plates. A water-soluble food dye mixture was also separated resulting in low band broadening and reduced developing time compared to HPTLC. For the latter example, mobile phase optimization on a single UTLC plate consisted of 14 developments with different mobile phases, each preceded by a plate prewashing step. The same plate was again reused for additional 11 separations under varying conditions resulting in a development procedure with a mean separation efficiency of 233,000theoretical plates/m and a reduced mobile phase consumption of only 400μL. This repeated use proved the physical robustness of the ultrathin layer and its resistance to damage. The layer was highly suited for hyphenation to ambient mass spectrometry, including desorption electrospray ionization (DESI) mass spectrometry imaging and direct analysis in real time (DART) mass spectrometry. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Obtenção e caracterização de materiais argilosos quimicamente ativados para utilização em catálise Preparation and characterization of chemically activated clays for use in catalysis

    Directory of Open Access Journals (Sweden)

    M. G. F. Rodrigues

    2006-12-01

    Full Text Available O principal objetivo deste trabalho é caracterizar argilas esmectíticas "Chocolate" de Boa-Vista, PB, tanto na sua forma natural quanto tratada quimicamente, visando sua aplicação em catálise. As argilas foram caracterizadas por fluorescência de raios X, difração de raios X e espectrofotometria de absorção óptica na região do infravermelho. Os resultados mostraram que o tratamento ácido alterou a estrutura da montmorilonita. A reação de isomerização do meta-xileno, para o material ativado, mostrou que a argila ácida foi mais ativa que a natural.The main objective of this paper is to characterize the chocolate smectite clays of Boa-Vista, PB, Brazil, in their natural form, and after chemical treatment, for their application in catalysis. The experimental methods were: X-ray fluorescence, X-ray diffraction and infrared spectroscopy. The results show that the acid treatment altered the montimorillonite structure. The obtained reaction (isomerization of m-xylene for the treated material showed that treated clays were more active than the natural ones.

  14. Characterization of RuO sub 2 electrodes for ferroelectric thin films prepared by metal-organic chemical-vapor deposition using Ru(C sub 1 sub 1 H sub 1 sub 9 O sub 2) sub 3

    CERN Document Server

    Lee, J M; Shin, J C; Hwang, C S; Kim, H J; Suk, C G

    1999-01-01

    Pure and conducting RuO sub 2 thin films were deposited on Si substrates at 250 approx 450 .deg. C using Ru(C sub 1 sub 1 H sub 1 sub 9 O sub 2) sub 3 as a precursor by low-pressure metal-organic chemical-vapor deposition (LP-MOCVD). At a lower deposition temperature,smoother and denser RuO sub 2 thin films were deposited. The RuO sub 2 thin films, which were crack free, adhered well onto the substrates and showed very low resistivities around 45 approx 60 mu OMEGA cm. RuO sub 2 thin films on (Ba, Sr)/TiO sub 3 /Pt/SiO sub 2 /Si showed good properties, indicating that MOCVD RuO sub 2 thin films from Ru(C sub 1 sub 1 H sub 1 sub 9 O sub 2) sub 3 can be applied as electrodes of high-dielectric thin films for capacitors in ultra-large-scale DRAMs.

  15. β-Ga2O3 versus ε-Ga2O3: Control of the crystal phase composition of gallium oxide thin film prepared by metal-organic chemical vapor deposition

    Science.gov (United States)

    Zhuo, Yi; Chen, Zimin; Tu, Wenbin; Ma, Xuejin; Pei, Yanli; Wang, Gang

    2017-10-01

    Gallium oxide thin films of β and ε phase were grown on c-plane sapphire using metal-organic chemical vapor deposition and the phase compositions were analyzed using X-ray diffraction. The epitaxial phase diagram was constructed as a function of the growth temperature and VI/III ratio. A low growth temperature and low VI/III ratio were beneficial for the formation of hexagonal-type ε-Ga2O3. Further structure analysis revealed that the epitaxial relationship between ε-Ga2O3 and c-plane sapphire is ε-Ga2O3 (0001) || Al2O3 (0001) and ε-Ga2O3 || Al2O3 . The structural evolution of the mixed-phase sample during film thickening was investigated. By reducing the growth rate, the film evolved from a mixed phase to the energetically favored ε phase. Based on these results, a Ga2O3 thin film with a phase-pure ε-Ga2O3 upper layer was successfully obtained.

  16. Radiation chemical synthesis

    International Nuclear Information System (INIS)

    Zagoretz, P.A.; Poluetkov, V.A.; Shostenko, A.G.

    1986-01-01

    The authors consider processes in radiation chemical synthesis which are being developed in various scientific-research organizations. The important advantages of radiation chlorination, viz. the lower temperature compared with the thermal method and the absence of dehydrochlorination products are discussed. The authors examine the liquid-phase chlorination of trifluorochloroethyltrichloromethyl ether to obtain the pentachloro-contining ether, trifluorodichloroethyltrichloromethyl ether. The authors discuss radiation synthesis processes that have be used formulated kinetic equations on which models have been based. It is concluded that the possibilities of preparative (micro- and low-tonnage) radiation synthesis are promising

  17. Newly introduced sample preparation techniques: towards miniaturization.

    Science.gov (United States)

    Costa, Rosaria

    2014-01-01

    Sampling and sample preparation are of crucial importance in an analytical procedure, representing quite often a source of errors. The technique chosen for the isolation of analytes greatly affects the success of a chemical determination. On the other hand, growing concerns about environmental and human safety, along with the introduction of international regulations for quality control, have moved the interest of scientists towards specific needs. Newly introduced sample preparation techniques are challenged to meet new criteria: (i) miniaturization, (ii) higher sensitivity and selectivity, and (iii) automation. In this survey, the most recent techniques introduced in the field of sample preparation will be described and discussed, along with many examples of applications.

  18. Sample preparation in alkaline media

    International Nuclear Information System (INIS)

    Nobrega, Joaquim A.; Santos, Mirian C.; Sousa, Rafael A. de; Cadore, Solange; Barnes, Ramon M.; Tatro, Mark

    2006-01-01

    The use of tetramethylammonium hydroxide, tertiary amines and strongly alkaline reagents for sample treatment involving extraction and digestion procedures is discussed in this review. The preparation of slurries is also discussed. Based on literature data, alkaline media offer a good alternative for sample preparation involving an appreciable group of analytes in different types of samples. These reagents are also successfully employed in tailored speciation procedures wherein there is a critical dependence on maintenance of chemical forms. The effects of these reagents on measurements performed using spectroanalytical techniques are discussed. Several undesirable effects on transport and atomization processes necessitate use of the method of standard additions to obtain accurate results. It is also evident that alkaline media can improve the performance of techniques such as inductively coupled plasma mass spectrometry and accessories, such as autosamplers coupled to graphite furnace atomic absorption spectrometers

  19. Preparation of thin nuclear targets

    International Nuclear Information System (INIS)

    Muggleton, A.H.F.

    1979-03-01

    Thin film backings, sources and targets are needed for many applications in low energy nuclear physics and nuclear chemistry experiments. A survey of techniques used in the preparation of nuclear targets is first briefly discussed. These are classified as chemical, mechanical and physical preparations. Vacuum evaporation, being the most generally used technique, is discussed in detail. It is highly desirable to monitor the film thickness and control the deposition rate during evaporation and to measure the final target thickness after deposition has concluded. The relative merits of various thickness measuring techniques are described. Stages in the fabrication and mounting of self-supporting foils are described in detail, with emphasis given to the preparation of thin self-supporting carbon foils used as target backings and stripper foils. Various target backings, and the merits of the more generally used release agents are described in detail. The preparations of more difficult elemental targets are discussed, and a comprehensive list of the common targets is presented

  20. Rare earths: preparation of spectro chemically pure standards, study of their carbonates and synthesis of a new compound series - the peroxy carbonates; Terras-raras: obtencao de padroes espectroquimicos, estudo dos carbonatos e sintese dos peroxicarbonatos. Uma nova serie de compostos

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz, Carlos Alberto da Silva

    1996-05-01

    In this work the following studies are concerned: I) preparation of lanthanum, cerium, praseodymium, neodymium and samarium oxides for use as spectro chemically pure standards; II) behavior of the rare earth (La, Ce, Pr, Nd, Sm) carbonates soluble in ammonium carbonate and mixture of ammonium carbonate/ammonium hydroxide, and III) synthesis and characterization of rare earth peroxy carbonates - a new series of compounds. Data for the synthesis and characterization of the rare earths peroxy carbonates described for the first time in this work are presented and discussed. With the aid of thermal analysis (TG-DTG) the thermal stability and the stoichiometric composition for new compounds were established and a mechanism of thermal decomposition was proposed. The peroxy carbonate was prepared by the addition of hydrogen peroxyde to the complexed soluble rare earths carbonates. These studies included also the determinations of active oxygen, the total rare earth oxide by gravimetry and complexometry and the C, H and N contents by microanalysis. The new compounds were also investigated by infrared spectroscopy. (author)

  1. Chemical pneumonitis

    Science.gov (United States)

    ... cleaning materials such as chlorine bleach, during industrial accidents, or near swimming pools) Grain and fertilizer dust ... and the A.D.A.M. Editorial team. Chemical Emergencies ... about A.D.A.M.'s editorial policy , editorial process and privacy policy . A.D.A.M. is ...

  2. Chemical dispersants

    NARCIS (Netherlands)

    Rahsepar, Shokouhalsadat; Smit, Martijn P.J.; Murk, Albertinka J.; Rijnaarts, Huub H.M.; Langenhoff, Alette A.M.

    2016-01-01

    Chemical dispersants were used in response to the Deepwater Horizon oil spill in the Gulf of Mexico, both at the sea surface and the wellhead. Their effect on oil biodegradation is unclear, as studies showed both inhibition and enhancement. This study addresses the effect of Corexit on oil

  3. Nanocrystalline CdS{sub 1−x}Se{sub x} alloys as thin films prepared by chemical bath deposition: Effect of x on the structural and optical properties

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Ramirez, E.A. [Escuela Superior de Ingeniería Química e Industrias Extractivas, Instituto Politécnico Nacional, CP 07738, México D.F. (Mexico); Hernandez-Perez, M.A., E-mail: mhernandezp0606@ipn.mx [Escuela Superior de Ingeniería Química e Industrias Extractivas, Instituto Politécnico Nacional, CP 07738, México D.F. (Mexico); Aguilar-Hernandez, J. [Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, CP 07738, México D.F. (Mexico); Rangel-Salinas, E. [Escuela Superior de Ingeniería Química e Industrias Extractivas, Instituto Politécnico Nacional, CP 07738, México D.F. (Mexico)

    2014-12-05

    Highlights: • CdS1−xSe{sub x} films with tunable structural and optical properties were grown by CBD. • Thin films are composed by a solid solution of the CdS{sub 1−x}Se{sub x} ternary alloy. • Crystal size, band gap and photoluminescence signal, decrease with the composition. • Ternary alloys show hexagonal phase with preferential orientation on (0 0 2) plane. • Films with x ⩾ 0.5 show semi-spherical grains composed by nanoworms structures. - Abstract: CdS{sub 1−x}Se{sub x} thin films were deposited on Corning glass substrates at 75 °C by chemical bath deposition (CBD) varying the composition “x” from 0 to 1 at a constant deposition time of 120 min. The composition of the films was adjusted by modifying the concentration as well as the ratio of the precursors. The morphological, compositional, structural and optical properties of the films were analyzed using several techniques such as Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), X-ray Diffraction (XRD), UV–Vis Spectroscopy (UV–Vis) and Photoluminescence (PL). The films grow as layers following the ion by ion mechanism, the density of the films decreases with x. Films are constituted by clusters (100–600 nm in diameter) of semispherical particles with sizes fluctuating from 10 to 20 nm. For x ⩾ 0.5 the particles are well-arranged in a “worm-like” structure. All the films are polycrystalline, to x = 0 (CdS) the cubic phase is present, the increase of composition promotes the formation of hexagonal phase or a mixture of both cubic and hexagonal phases. Preferential orientation in the (1 0 0) or (0 0 2) plane is observed. The crystal size decreases from 20 to 6 nm when x is increased. The optical properties can be easily tuned by adjusting the composition. Optical absorption analysis shows that the band gap (E{sub g}) value shifts to red in function of x (from 2.47 to 1.99 eV). Photoluminescence signal changes as “x” varies showing a regular behavior

  4. Career Opportunities in Chemistry and Chemical Engineering.

    Science.gov (United States)

    Glover, Trienne

    This pamphlet discusses career and employment opportunities in chemical engineering. Necessary college preparation is described and median salaries by degree are tabulated. Nontraditional careers in chemistry are also described. Future demand for chemists and chemical engineers is projected to 1985 and the availability of jobs for women and…

  5. Rhenium Nanochemistry for Catalyst Preparation

    Directory of Open Access Journals (Sweden)

    Vadim G. Kessler

    2012-08-01

    Full Text Available The review presents synthetic approaches to modern rhenium-based catalysts. Creation of an active center is considered as a process of obtaining a nanoparticle or a molecule, immobilized within a matrix of the substrate. Selective chemical routes to preparation of particles of rhenium alloys, rhenium oxides and the molecules of alkyltrioxorhenium, and their insertion into porous structure of zeolites, ordered mesoporous MCM matrices, anodic mesoporous alumina, and porous transition metal oxides are considered. Structure-property relationships are traced for these catalysts in relation to such processes as alkylation and isomerization, olefin metathesis, selective oxidation of olefins, methanol to formaldehyde conversion, etc.

  6. Nuclear industry - challenges in chemical engineering

    International Nuclear Information System (INIS)

    Sen, S.; Sunder Rajan, N.S.; Balu, K.; Garg, R.K.; Murthy, L.G.K.; Ramani, M.P.S.; Rao, M.K.; Sadhukhan, H.K.; Venkat Raj, V.

    1978-01-01

    As chemical engineering processes and operations are closely involved in many areas of nuclear industry, the chemical engineer has a vital role to play in its growth and development. An account of the major achievements of the Indian chemical engineers in this field is given with view of impressing upon the faculty members of the Indian universities the need for taking appropriate steps to prepare chemical engineers suitable for nuclear industry. Some of the major achievements of the Indian chemical engineers in this field are : (1) separation of useful minerals from beach sand, (2) preparation of thorium nitrate of nuclear purity from monazite, (3) processing of zircon sand to obtain nuclear grade zirconium and its separation from hafnium to obtain zirconium metal sponge, (4) recovery of uranium from copper tailings, (5) economic recovery of nuclear grade uranium from low grade uranium ores found in India, (6) fuel reprocessing, (7) chemical processing of both low and high level radioactive wastes. (M.G.B.)

  7. Formulation, Preparation, and Characterization of Polyurethane Foams

    Science.gov (United States)

    Pinto, Moises L.

    2010-01-01

    Preparation of laboratory-scale polyurethane foams is described with formulations that are easy to implement in experiments for undergraduate students. Particular attention is given to formulation aspects that are based on the main chemical reactions occurring in polyurethane production. This allows students to develop alternative formulations to…

  8. Preparation and characterisation of activated carbon

    International Nuclear Information System (INIS)

    Badri bin Muhammad; Karen binti Badri; Mohd Zobir bin Hussein; Zulkarnain bin Zainal; W.M. Daud bin W Yunus; Ramli bin Ibrahim

    1994-01-01

    Activated carbon was prepared from Agricultural wastes, such as coconut shell, Palm oil Shell and mangrove trunk by destructive distillation under vakuum. Chemical and Physical properties of the activated carbon were studied and some potentially useful application in the fields of chemistry was also carried out

  9. THE USE OF CHEMICALS IN THE FIELD OF FARM ANIMAL HEALTH (NUTRITION, ENTOMOLOGY, PATHOLOGY). AGRICULTURAL CHEMICALS TECHNOLOGY, NUMBER 7.

    Science.gov (United States)

    Ohio State Univ., Columbus. Center for Vocational and Technical Education.

    DEVELOPED BY A NATIONAL TASK FORCE ON THE BASIS OF STATE STUDIES, THIS MODULE IS ONE OF A SERIES DESIGNED TO ASSIST TEACHERS IN PREPARING POST-SECONDARY STUDENTS FOR AGRICULTURAL CHEMICAL OCCUPATIONS. THE SPECIFIC OBJECTIVE OF THIS MODULE IS TO PREPARE TECHNICIANS IN THE FIELD OF THE USE OF CHEMICALS FOR ANIMAL HEALTH. SECTIONS INCLUDE -- (1)…

  10. Household Chemical Emergencies

    Science.gov (United States)

    ... Content Home Be Informed Household Chemical Emergencies Household Chemical Emergencies Although the risk of a chemical accident ... reduce the risk of injury. Before a Household Chemical Emergency It is critical to store household chemicals ...

  11. Chemical cosmology

    CERN Document Server

    Boeyens, Jan CA

    2010-01-01

    The composition of the most remote objects brought into view by the Hubble telescope can no longer be reconciled with the nucleogenesis of standard cosmology and the alternative explanation, in terms of the LAMBDA-Cold-Dark-Matter model, has no recognizable chemical basis. A more rational scheme, based on the chemistry and periodicity of atomic matter, opens up an exciting new interpretation of the cosmos in terms of projective geometry and general relativity. The response of atomic structure to environmental pressure predicts non-Doppler cosmical redshifts and equilibrium nucleogenesis by alp

  12. Method for producing chemical energy

    Science.gov (United States)

    Jorgensen, Betty S.; Danen, Wayne C.

    2004-09-21

    Fluoroalkylsilane-coated metal particles having a central metal core, a buffer layer surrounding the core, and a fluoroalkylsilane layer attached to the buffer layer are prepared by combining a chemically reactive fluoroalkylsilane compound with an oxide coated metal particle having a hydroxylated surface. The resulting fluoroalkylsilane layer that coats the particles provides them with excellent resistance to aging. The particles can be blended with oxidant particles to form energetic powder that releases chemical energy when the buffer layer is physically disrupted so that the reductant metal core can react with the oxidant.

  13. Biological and biochemical evaluation of some prepared high ...

    African Journals Online (AJOL)

    Biological and biochemical evaluation of some prepared high antioxidant fruit beverages as functional foods. W A El-Malky ... The beverage which contain mango, red grape, carrot and tomato was the best prepared beverages according to the sensory evaluation, chemical composition and antioxidant activity. The high ...

  14. 29 CFR 1915.33 - Chemical paint and preservative removers.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Chemical paint and preservative removers. 1915.33 Section... Preparation and Preservation § 1915.33 Chemical paint and preservative removers. (a) Employees shall be protected against skin contact during the handling and application of chemical paint and preservative...

  15. Gardner's commercially important chemicals: synonyms, trade names, and properties

    National Research Council Canada - National Science Library

    Milne, George W. A

    2005-01-01

    ... provided for individual chemical compounds. Book In the preparation of this an effort has been made to include useful information on chemicals that play a significant role in commerce. The US Environmental Protection Agency (EPA), in cooperation with industry, maintains a list of "High Production Volume" (HPV) chemicals whose productio...

  16. Survey of awareness about hazardous chemicals of residents living near chemical plants in South Korea.

    Science.gov (United States)

    Han, Don-Hee; Park, Min Soo

    2018-02-10

    With economic growth, the use of chemicals has continually increased, resulting in an increase of chemical accidents. Chemical accidents pose a life threat and can lead to many health problems among the residents living in close proximity to chemical plants. This study aimed to investigate the awareness of the residents living near chemical plants about hazardous chemicals, as well as to survey the awareness of workers who do not directly handle chemicals at chemical plants (WNHCs). To this end, a questionnaire survey was conducted among a total of 600 residents and 160 WNHCs. The questionnaire was composed of three items: awareness of chemical risk, awareness of countermeasures in chemical accidents, and imperious necessity of PPE (personal protective equipment). Statistical analysis of the data was performed with the Statistical Package for Social Sciences (SPSS) version 18.0. The results show that the government needs to complement the notification system of chemical risk for residents who live close to chemical plants. The highest priority of PPE which residents want to prepare for chemical accidents was respiratory protective equipment (RPE). They responded that, if necessary to purchase PPE, they could bear a portion of the expenses (up to US $30). This study provides basic data for the development of programs and policies on chemical safety relevant for the residents living in close proximity to chemical plants in South Korea.

  17. Sample preparation of Medicago sativa L. hay for chemical analysis ...

    African Journals Online (AJOL)

    The objective of this study was to quantify the effect of the grinding procedure on the moisture and crude protein concentration of a ground Medicago sativa L. hay sample for quality grading. An additional aim was to investigate the accuracy of electronic moisture testers (EMT). Variance of analyses revealed significant ...

  18. Preparation of Chemical Samples On Relevant Surfaces Using Inkjet Technology

    Science.gov (United States)

    2013-04-01

    printer. For the results in Section 3.1, 32 g/L of potassium chlorate was printed on a 2 × 2 in. pattern of aluminum substrate. All of the printed...maintained at 80 °C. Figures 6 and 7 are photographs of potassium chlorate crystals deposited with and without heating. Both photographs are at the...submicron size range. Figures B-1 and B-2 shows potassium chlorate crystals deposited with and without heating. Both photographs are at the same

  19. Characterization of silver nanoparticles prepared by wet chemical ...

    African Journals Online (AJOL)

    Results: The silver nanoparticles formed were spherical in shape with mean size of 10.3 nm. The ... antibacterial activity against various strains of bacteria. Keywords: Wet ..... Fang J, Zhong C, Mu R. The study of deposited silver particulate ...

  20. Preparation, dielectric and a.c. conductivity studies on chemically ...

    African Journals Online (AJOL)

    user

    methods included alkali treatment, H2SO4 treatment, combined H2SO4, and alkali-thermal treatment. .... presence of impurities, lignin and cellulosic group and water dipoles present in sisal fibers ... groups; thereby making them more reactive .

  1. Polyoxometalate based soft chemical route for preparation of Pt ...

    Indian Academy of Sciences (India)

    Unknown

    2005-01-17

    Jan 17, 2005 ... ple, one could control these parameters by adopting vari- ous synthetic strategies and in recent years, several approaches have been considered. Typical ones include using channels in macroporous membranes (Martin et al. 1999), mesoporous materials (Han et al 2000), carbon nanotubes (Ugarte et al ...

  2. Preparation, Chemical Modification and Absorption Properties of Various Phthalocyanines

    Czech Academy of Sciences Publication Activity Database

    Klusoň, Petr; Drobek, M.; Kalaji, A.; Karásková, M.; Rakušan, J.

    2009-01-01

    Roč. 35, č. 1 (2009), s. 103-116 ISSN 0922-6168 R&D Projects: GA ČR GA104/09/0694; GA AV ČR KAN400720701 Institutional research plan: CEZ:AV0Z40720504 Keywords : phtalocyanines * spectroscopy * phthalodinitrile Subject RIV: CC - Organic Chemistry Impact factor: 0.813, year: 2009

  3. A roadmap to high quality chemically prepared graphene

    NARCIS (Netherlands)

    Gengler, Regis Y. N.; Spyrou, Konstantinos; Rudolf, Petra

    2010-01-01

    Graphene was discovered half a decade ago and proved the existence of a two-dimensional system which becomes stable as a result of 3D corrugation. It appeared very quickly that this exceptional material had truly outstanding electronic, mechanical, thermal and optical properties. Consequently a

  4. Preparative chromatography of fine chemicals and pharmaceutical agents

    National Research Council Canada - National Science Library

    Schmidt-Traub, H

    2005-01-01

    ... Isotherms 34 Multi-component Isotherms 36 Ideal Adsorbed Solution (IAS) Theory 37 Thermodynamic Effects on Mass Separation 41 Mass Load 41 Linear and Nonlinear Isotherms 41 Elution Modes 46 2.1...

  5. Properties of FeCo nanopowder prepared by chemical synthesis

    Czech Academy of Sciences Publication Activity Database

    Zábranský, Karel; Schneeweiss, Oldřich

    2010-01-01

    Roč. 61, č. 5 (2010), s. 299-301 ISSN 1335-3632. [NANOVED 2010. Bratislava, 16.05.2010-19.05.2010] R&D Projects: GA MŠk 1M0512; GA ČR GA106/08/1440 Institutional research plan: CEZ:AV0Z20410507 Keywords : FeCo alloys * nanoparticles * magnetic properties Subject RIV: JG - Metallurgy Impact factor: 0.270, year: 2010

  6. Sample preparation of Medicago sativa L. hay for chemical analysis

    African Journals Online (AJOL)

    UFS Campus

    wavelength region (De Boever et al., 1996; Williams & Norris, 2001). Therefore, it could affect the predicted results of all the other parameters (CP, ADF, NDF, etc.). The grinding ... (September 2006 to May 2007). The samples represented lots that were selected at different stages of maturity. A moisture range as broad as ...

  7. Chemical sensors for nuclear industry

    International Nuclear Information System (INIS)

    Gnanasekaran, K.I.

    2012-01-01

    Development of chemical sensors for detection of gases at trace levels for applications in nuclear industry will be highlighted. The sensors have to be highly sensitive, reliable and rugged with long term stability to operate in harsh industrial environment. Semiconductor and solid electrolyte based electrochemical sensors satisfy the requirements. Physico-chemical aspects underlying the development of H 2 sensors in sodium and in cover gas circuit of the Fast breeder reactors for its smooth functioning, NH 3 and H 2 S sensors for use in Heavy water production industries and NO x sensors for spent fuel reprocessing plants will be presented. Development of oxygen sensors to monitor the oxygen level in the reactor containments and sodium sensors for detection of sodium leakages will also be discussed. The talk will focus the general aspects of identification of the sensing material for the respective analyte species, development of suitable chemical route for preparing them as fine powders, the need for configuring them in thick film or thin film geometries and their performance. Pulsed laser deposition method, an elegant technique to prepare the high quality thin films of multicomponent oxides is demonstrated for preparation of nanostructured thin films of complex oxides and its use in tailoring the morphology of the complex sensing material in the desired form by optimizing the in-situ growth conditions. (author)

  8. Materials Preparation Center

    Data.gov (United States)

    Federal Laboratory Consortium — MPC is recognized throughout the worldwide research community for its unique capabilities in purification, preparation, and characterization of: rare earth metals,...

  9. Chemical composition of patikaraparpam.

    Science.gov (United States)

    Saraswathy, A; Rani, M G; Susan, T; Purushothaman, K K

    1997-04-01

    Patikaraparpam, a Siddha formulation in prepared by trituration of potash alum with egg albumin followed by calcinatin. The three authentic laboratories made parpams as well as six commercial samples have been examined for their chemical composition. The analytical data that emerged from the analysis of the above samples showed that seven parpams contained only aluminium sulphate and they did respond to tests for potassium. An inspection of the crude drugs patikaram' available in the market established that potash alum and ammonia alum are indiscriminateldy taken for use, according to literature, only potash alum should be used in Indian system of medicine. Patikarapparapam is indicated in urinary inflammations and obstructions and is a reputed diuretic. Potassium salts are established diuretic. These studies show that the raw drugs sellers, the pharamaceutists or manufacturers of medicine and the physician as well should make sure that only potash alum is used in Indian medicine.

  10. Chemical aspects of rubidium uranium sulphate for its use as a chemical standard for uranium

    International Nuclear Information System (INIS)

    Singh Mudher, K.D.; Khandekar, R.R.; Krishnan, K.; Jayadevan, N.C.; Sood, D.D.

    1989-01-01

    Rb 2 U(SO 4 ) 3 , a double sulphate of rubidium and uranium(IV) has been prepared and investigated for its use as a chemical standard for uranium. The compound can be easily prepared and crystallised in a pure form. The results of physico-chemical characterisation on preparation of 5-10 g. lots are described in this report. These studies suggest that the compound is anhydrous, stoichiometric, stable to atmospheric effects and easily soluble in acids and thus satisfies most of the criteria for a primary standard. (author). 13 refs., 4 figs., 6 tabs

  11. CAMEO Chemicals Software

    Science.gov (United States)

    CAMEO Chemicals is an extensive chemical database, available for download, with critical response information for thousands of chemicals, and a tool that tells you what reactions might occur if chemicals were mixed together.

  12. Documents preparation and review

    International Nuclear Information System (INIS)

    1999-01-01

    Ignalina Safety Analysis Group takes active role in assisting regulatory body VATESI to prepare various regulatory documents and reviewing safety reports and other documentation presented by Ignalina NPP in the process of licensing of unit 1. The list of main documents prepared and reviewed is presented

  13. CHEMICAL EVOLUTION

    Energy Technology Data Exchange (ETDEWEB)

    Calvin, Melvin

    1965-06-01

    How did life come to be on the surface of the earth? Darwin himself recognized that his basic idea of evolution by variation and natural selection must be a continuous process extending backward in time through that period in which the first living things arose and into the period of 'Chemical Evolution' which preceded it. We are approaching the examination of these events by two routes. One is to seek for evidence in the ancient rocks of the earth which were laid down prior to that time in which organisms capable of leaving their skeletons in the rocks to be fossilized were in existence. This period is sometime prior to approximately 600 million years ago. The earth is believed to have taken its present form approximately 4700 million years ago. We have found in rocks whose age is about 1000 million years certain organic molecules which are closely related to the green pigment of plants, chlorophyll. This seems to establish that green plants were already fluorishing prior to that time. We have now found in rocks of still greater age, namely, 2500 million years, the same kinds of molecules mentioned above which can be attributed to the presence of living organisms. If these molecules are as old as the rocks, we have thus shortened the time available for the generation of the complex biosynthetic sequences which give rise to these specific hydrocarbons (polyisoprenoids) to less than 2000 million years.

  14. Chemical thermodynamics of uranium

    International Nuclear Information System (INIS)

    Grenthe, I.; Fuger, J.; Lemire, R.J.; Muller, A.B.; Nguyen-Trung Cregu, C.; Wanner, H.

    1992-01-01

    A comprehensive overview on the chemical thermodynamics of those elements that are of particular importance in the safety assessment of radioactive waste disposal systems is provided. This is the first volume in a series of critical reviews to be published on this subject. The book provides an extensive compilation of chemical thermodynamic data for uranium. A description of procedures for activity corrections and uncertainty estimates is given. A critical discussion of data needed for nuclear waste management assessments, including areas where significant gaps of knowledge exist is presented. A detailed inventory of chemical thermodynamic data for inorganic compounds and complexes of uranium is listed. Data and their uncertainty limits are recommended for 74 aqueous complexes and 199 solid and 31 gaseous compounds containing uranium, and on 52 aqueous and 17 solid auxiliary species containing no uranium. The data are internally consistent and compatible with the CODATA Key Values. The book contains a detailed discussion of procedures used for activity factor corrections in aqueous solution, as well as including methods for making uncertainty estimates. The recommended data have been prepared for use in environmental geochemistry. Containing contributions written by experts the chapters cover various subject areas such a s: oxide and hydroxide compounds and complexes, the uranium nitrides, the solid uranium nitrates and the arsenic-containing uranium compounds, uranates, procedures for consistent estimation of entropies, gaseous and solid uranium halides, gaseous uranium oxides, solid phosphorous-containing uranium compounds, alkali metal uranates, uncertainties, standards and conventions, aqueous complexes, uranium minerals dealing with solubility products and ionic strength corrections. The book is intended for nuclear research establishments and consulting firms dealing with uranium mining and nuclear waste disposal, as well as academic and research institutes

  15. Chemical Engineering in Space

    Science.gov (United States)

    Lobmeyer, Dennis A.; Meneghelli, Barry; Steinrock, Todd (Technical Monitor)

    2001-01-01

    sources is paramount to success. We are currently working on several processes to produce the propellants that would allow us to visit and explore the surface of Mars. The capabilities currently at our disposal for launching and delivering equipment to another planet or satellite dictate that the size and scale of any hardware must be extremely small. The miniaturization of the processes needed to prepare the in situ propellants and life support commodities is a real challenge. Chemical engineers are faced with the prospect of reproducing an entire production facility in miniature so the complex can be lifted into space and delivered to our destination. Another area that does not normally concern chemical engineers is the extreme physical aspects payloads are subjected to with the launch of a spacecraft. Extreme accelerations followed by the sudden loss of nearly all gravitational forces are well outside normal equipment design conditions. If the equipment cannot survive the overall trip, then it obviously will not be able to yield the needed products upon arrival. These launch constraints must be taken into account. Finally, we must consider both the effectiveness and efficiencies of the processes. A facility located on the Moon or Mars will not have an unlimited supply of power or other ancillary utilities. For a Mars expedition, the available electric power is severely limited. The design of both the processes and the equipment must be considered. With these constraints in mind, only the most efficient designs will be viable. Cryogenics, in situ resource utilization, miniaturization, launchability, and power/process efficiencies are only a few of the areas that chemical engineers provide support and expertise for the exploration of space.

  16. PREPARATIVE SKIN PREPARATION AND SURGICAL WOUND INFECTION

    Directory of Open Access Journals (Sweden)

    Anjanappa

    2015-01-01

    Full Text Available BACKGROUND AND OBJECTIVE: It is an established fact now that the normal skin of healthy human beings harbours a rich bacterial fl ora. Normally considered non - pathogenic , these organisms way be a potential source of infection of the surgical wound. Approximately 20% of the resident flora is beyond the reach of surgical scrubs and antiseptics. The goal of surgical preparation of the skin with antiseptics is to remove transient and pathogenic microorganisms on the skin surface and to reduce the resident flora to a low level. Povidone iodine (I odophors and chlorhexidine are most often used antiseptics for pre - operative skin preparation. OBJECTIVES : To evaluate the efficacy of povidone iodine alone and in combination with antiseptic agent containing alcoholic chlorhexidine in preoperative skin p reparation by taking swab culture. (2 To compare the rate of postoperative wound infection in both the groups. METHODS: One hundred patients (fifty in each group undergoing clean elective surgery with no focus of infection on the body were included in th e study. The pre - operative skin preparation in each group is done with the respective antiseptic regimen. In both the groups after application of antiseptics , sterile saline swab culture was taken immediately from site of incision. In cases which showed gr owth of organisms , the bacteria isolated were identified by their morphological and cultural characteristics. Grams staining , coagulase test and antibiotic sensitivity test were done wherever necessary and difference in colonization rates was determined as a measure of efficacy of antiseptic regimen. RESULTS: The results of the study showed that when compared to povidone iodine alone , using a combination of povidone iodine and alcoholic solution of chlorhexidine , the colonization rates of the site of incisi on were reduced significantly. As for the rate of post - operative wound infection , it is also proven that wound infections are also

  17. Organic astatine compounds, their preparation and properties

    Energy Technology Data Exchange (ETDEWEB)

    Vasaros, L; Berei, K

    1985-01-01

    Aromatic astatine compounds of possible medical application were prepared by high energy substitutions, by astatine-halogen, and by electrophil astatine-hydrogen substitutions at the Joint Institute of Nuclear Researches, Dubna. Physico-chemical properties of organic astatine compounds such as boiling point and evaporation heat, and the refraction and dissociation energy of carbon-astatine bonds were determined experimentally by gas chromatography. The results are compared with extrapolated data. (V.N.). 41 refs.; 7 figs.; 5 tables.

  18. Preparation of TiC single crystals

    International Nuclear Information System (INIS)

    Scheerer, B.; Fink, J.; Reichardt, W.

    1975-07-01

    TiC single crystals were prepared by vertical zone melting for measurements of the phonon dispersion by inelastic neutron scattering. The influence of the starting material and of the growing conditions on the growth of the crystal were studied. The crystals were characterized by chemical methods, EMX and neutron diffraction. It was possible to grow single crystals with a volume of up to 0.6 cm 3 and mosaic spread of less then 0.4 0 . (orig.) [de

  19. Chemical vapour deposition of carbon nanotubes

    CSIR Research Space (South Africa)

    Arendse, CJ

    2006-02-01

    Full Text Available , effective, more versatile and easily scalable to large substrate sizes. In this paper, we present a design of the hot-wire CVD system constructed at the CSIR for the deposition of CNTs. Additionally, we will report on the structure of CNTs deposited... exhibit exceptional chemical and physical properties related to toughness, chemical inertness, magnetism, and electrical and thermal conductivity. A variety of preparation methods to synthesise CNTs are known, e.g. carbon-arc discharge, laser ablation...

  20. Preparation of bromine fluoride

    International Nuclear Information System (INIS)

    Domange, Pr; Duflo, J.

    1958-05-01

    This note addresses the preparation of bromine fluoride. It indicates the implemented process for the reaction, used products (fluorine and bromine), and column characteristics. It describes the operating mode. Apparatus drawing is provided

  1. Dukovany ASSET mission preparation

    Energy Technology Data Exchange (ETDEWEB)

    Kouklik, I [NPP Dukovany (Czech Republic)

    1997-12-31

    We are in the final stages of the Dukovany ASSET mission 1996 preparation. I would like to present some of our recent experiences. Maybe they would be helpful to other plants, that host ASSET missions in future.

  2. Sperm preparation for fertilization

    NARCIS (Netherlands)

    Gadella, B.M.

    2014-01-01

    Description This book contains 19 chapters that discuss theoretical and applied andrology for domestic, zoo and wild animals. Topics include semen and its constituents; sperm production and harvest; determinants of sperm morphology; sperm preparation for fertilization; practical aspects of semen

  3. Dukovany ASSET mission preparation

    International Nuclear Information System (INIS)

    Kouklik, I.

    1996-01-01

    We are in the final stages of the Dukovany ASSET mission 1996 preparation. I would like to present some of our recent experiences. Maybe they would be helpful to other plants, that host ASSET missions in future

  4. FERMILAB: Preparing to collide

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Against the background of stringent Environment, Safety and Health (ES&H) regulations mandated by the US Department of Energy for all national Labs, Fermilab prepared to mount the next major Tevatron proton-antiproton collider run

  5. Preparation of silver doped high temperature superconductors

    International Nuclear Information System (INIS)

    Stavek, Jiri; Zapletal, Vladimir

    1989-01-01

    High temperature superconductors were prepared by the controlled double-jet precipitation to manipulate the chemical composition, composition gradients, average grain size, grain size distribution, and other factors which contribute to the actual properties and performance of HTSC. The cations (Y-Ba-Cu or Bi-Pb-Ca-Sr-Cu) and oxalic anions solutions were simultaneously separately introduced to the crystallizer with a stirred solution of gelatin under conditions where the temperature, excess of oxalic anions in solution, pH, reactant addition rate, and other reaction conditions were tightly controlled to prepare the high sinterability powder. To increase the sinterability of submicron particles of produced precursor, the silver ions were introduced at the end of the controlled double-jet precipitation. This approach improves the electrical and mechanical properties of produced HTSC specimens. The controlled double jet precipitation provides a viable technique for preparation of oxide superconductors and the process is amenable for scaling up

  6. An X-band Co{sup 2+} EPR study of Zn{sub 1−x}Co{sub x}O (x=0.005–0.1) nanoparticles prepared by chemical hydrolysis methods using diethylene glycol and denaturated alcohol at 5 K

    Energy Technology Data Exchange (ETDEWEB)

    Misra, Sushil K., E-mail: skmisra@alcor.concordia.ca [Physics Department, Concordia University, Montreal, QC, Canada H3G 1M8 (Canada); Andronenko, S.I. [Physics Institute, Kazan Federal University, Kazan 420008 (Russian Federation); Srinivasa Rao, S.; Chess, Jordan; Punnoose, A. [Department of Physics, Boise State University, Boise, ID 83725-1570 (United States)

    2015-11-15

    EPR investigations on two types of dilute magnetic semiconductor (DMS) ZnO nanoparticles doped with 0.5–10% Co{sup 2+} ions, prepared by two chemical hydrolysis methods, using: (i) diethylene glycol ((CH{sub 2}CH{sub 2}OH){sub 2}O) (NC-rod-like samples), and (ii) denatured ethanol (CH{sub 3}CH{sub 2}OH) solutions (QC-spherical samples), were carried out at X-band (9.5 GHz) at 5 K. The analysis of EPR data for NC samples revealed the presence of several types of EPR lines: (i) two types, intense and weak, of high-spin Co{sup 2+} ions in the samples with Co concentration >0.5%; (ii) surface oxygen vacancies, and (iii) a ferromagnetic resonance (FMR) line. QC samples exhibit an intense FMR line and an EPR line due to high-spin Co{sup 2+} ions. FMR line is more intense, than the corresponding line exhibited by NC samples. These EPR spectra varied for sample with different doping concentrations. The magnetic states of these samples as revealed by EPR spectra, as well as the origin of ferromagnetism DMS samples are discussed. - Highlights: • 5 K X band Co{sup 2+} EPR investigations on QC and NC ZnO dilute magnetic semiconductor nanoparticles. • NC and QC samples exhibited high-spin Co{sup 2+} EPR lines and ferromagnetic resonance line. • NC sample also exhibit line due surface oxygen vacancies. • FMR line is more intense in QC than that in NC samples. • Magnetic states and the origin of ferromagnetism are discussed.

  7. Effect of preparation conditions on physicochemical, surface and catalytic properties of cobalt ferrite prepared by coprecipitation

    Energy Technology Data Exchange (ETDEWEB)

    El-Shobaky, G.A., E-mail: elshobaky@yahoo.co [Physical Chemistry Department, National Research Center, Dokki, Cairo (Egypt); Turky, A.M.; Mostafa, N.Y.; Mohamed, S.K. [Chemistry Department, Faculty of Science, Suez Canal University, Ismailia 41522 (Egypt)

    2010-03-18

    Cobalt ferrite nanoparticles were prepared via thermal treatment of cobalt-iron mixed hydroxides at 400-600 {sup o}C. The mixed hydroxides were coprecipitated from their nitrates solutions using NaOH as precipitating agent. The effects of pH and temperature of coprecipitation and calcination temperature on the physicochemical, surface and catalytic properties of the prepared ferrites were studied. The prepared systems were characterized using TG, DTG, DTA, chemical analysis, atomic absorption spectroscopy (AAS), X-ray diffraction (XRD), energy dispersive X-ray (EDX) as well as surface and texture properties based on nitrogen adsorption-desorption isotherms. The prepared cobalt ferrites were found to be mesoporous materials that have crystallite size ranges between 8 and 45 nm. The surface and catalytic properties of the produced ferrite phase were strongly dependent on coprecipitation conditions of the mixed hydroxides and on their calcination temperature.

  8. The hospital preparation of radiopharmaceuticals

    International Nuclear Information System (INIS)

    The subject is covered in sections: introduction; preparation ((general - sterilization), production areas (laboratories), working methods for injections, working methods for oral preparations and iodination procedures); analytical testing (general, standards common to injections and oral preparations, standards for injections, standards for oral preparations); reliable methods of preparing sup(99m)Tc-radiopharmaceuticals and 51 Cr-red cells; commercial radiopharmaceutical kits. (U.K.)

  9. Preparation and integration of nanostructured titanium dioxide

    KAUST Repository

    Zeng, Hua Chun

    2011-10-01

    Titanium dioxide (TiO2) is a chemically stable nontoxic transition-metal oxide associated with a wide range of existing chemical engineering processes. In this short review, recent research endeavors in preparation and integration of nanostructured TiO2 materials system will be featured and discussed for their potential new applications. Because material development always plays pivotal roles in the progress of a particular engineering discipline, the reviewed subjects will provide useful information to stimulate nanoscale research of chemical engineering, linking established fundamentals with practical applications. Some critical issues and challenges regarding further development of this important functional material for nanotechnology will also be addressed. © 2011 Elsevier Ltd. All rights reserved.

  10. Chemical Function Predictions for Tox21 Chemicals

    Data.gov (United States)

    U.S. Environmental Protection Agency — Random forest chemical function predictions for Tox21 chemicals in personal care products uses and "other" uses. This dataset is associated with the following...

  11. Chemical Weathering on Venus

    Science.gov (United States)

    Zolotov, Mikhail

    2018-01-01

    , volcanic, impact, and atmospheric settings. On highly deformed tessera terrains, more ancient rocks of unknown composition could reflect interactions with putative water-rich atmospheres and even aqueous solutions. Salt-, Fe oxide, or silica-rich formations would indicate past aqueous processes. The apparent diversity of affected solids, surface temperatures, pressures, and gas/fluid compositions throughout Venus's history implies multiple signs of chemical alteration, which remain to be investigated. The current understanding of chemical weathering is limited by the uncertain composition of the deep atmosphere, by the lack of direct data on the phase composition of surface materials, and by the uncertain data on thermodynamics of minerals and their solid solutions. In the preparation for further entry probe and lander missions, rock alteration needs to be investigated through chemical kinetic experiments and calculations of solid-gas(fluid) equilibria to constrain past and present processes.

  12. Journal of Chemical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Laser flash photolysis studies were carried out on two types of silver nanoparticles prepared by ... Type II silver nanoparticles showed a 390 nm surface plasmon band with a shoulder at 550 nm. ... Journal of Chemical Sciences | News.

  13. Endocrine Disrupting Chemicals (EDCs)

    Science.gov (United States)

    ... Center Pacientes y Cuidadores Hormones and Health The Endocrine System Hormones Endocrine Disrupting Chemicals (EDCs) Steroid and Hormone ... Hormones and Health › Endocrine Disrupting Chemicals (EDCs) The Endocrine System Hormones Endocrine Disrupting Chemicals (EDCs) EDCs Myth vs. ...

  14. Microfluidic chemical reaction circuits

    Science.gov (United States)

    Lee, Chung-cheng [Irvine, CA; Sui, Guodong [Los Angeles, CA; Elizarov, Arkadij [Valley Village, CA; Kolb, Hartmuth C [Playa del Rey, CA; Huang, Jiang [San Jose, CA; Heath, James R [South Pasadena, CA; Phelps, Michael E [Los Angeles, CA; Quake, Stephen R [Stanford, CA; Tseng, Hsian-rong [Los Angeles, CA; Wyatt, Paul [Tipperary, IE; Daridon, Antoine [Mont-Sur-Rolle, CH

    2012-06-26

    New microfluidic devices, useful for carrying out chemical reactions, are provided. The devices are adapted for on-chip solvent exchange, chemical processes requiring multiple chemical reactions, and rapid concentration of reagents.

  15. Chemical Emergencies Overview

    Science.gov (United States)

    ... Address What's this? Submit What's this? Submit Button Chemical Emergencies Overview Recommend on Facebook Tweet Share Compartir ... themselves during and after such an event. What chemical emergencies are A chemical emergency occurs when a ...

  16. Recent advances in applications of nanomaterials for sample preparation.

    Science.gov (United States)

    Xu, Linnan; Qi, Xiaoyue; Li, Xianjiang; Bai, Yu; Liu, Huwei

    2016-01-01

    Sample preparation is a key step for qualitative and quantitative analysis of trace analytes in complicated matrix. Along with the rapid development of nanotechnology in material science, numerous nanomaterials have been developed with particularly useful applications in analytical chemistry. Benefitting from their high specific areas, increased surface activities, and unprecedented physical/chemical properties, the potentials of nanomaterials for rapid and efficient sample preparation have been exploited extensively. In this review, recent progress of novel nanomaterials applied in sample preparation has been summarized and discussed. Both nanoparticles and nanoporous materials are evaluated for their unusual performance in sample preparation. Various compositions and functionalizations extended the applications of nanomaterials in sample preparations, and distinct size and shape selectivity was generated from the diversified pore structures of nanoporous materials. Such great variety make nanomaterials a kind of versatile tools in sample preparation for almost all categories of analytes. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. The Control of Chemical and Biological Weapons.

    Science.gov (United States)

    Alexander, Archibald S.; And Others

    This book is composed of four papers prepared to illuminate the problem areas which might arise if the policies of the 1925 Geneva Protocol and other measures to limit chemical and biological weapons are ratified by the United States Senate. The papers included are: Legal Aspects of the Geneva Protocol of 1925; The Use of Herbicides in War: A…

  18. Size dependent optical characteristics of chemically deposited

    Indian Academy of Sciences (India)

    Keywords. Thin film; ZnS; CBD method; optical properties. Abstract. ZnS thin films of different thicknesses were prepared by chemical bath deposition using thiourea and zinc acetate as S2- and Zn2+ source. The effect of film thickness on the optical and structural properties was studied. The optical absorption studies in the ...

  19. Computer Applications in Balancing Chemical Equations.

    Science.gov (United States)

    Kumar, David D.

    2001-01-01

    Discusses computer-based approaches to balancing chemical equations. Surveys 13 methods, 6 based on matrix, 2 interactive programs, 1 stand-alone system, 1 developed in algorithm in Basic, 1 based on design engineering, 1 written in HyperCard, and 1 prepared for the World Wide Web. (Contains 17 references.) (Author/YDS)

  20. Preparation of alumina microspheres

    International Nuclear Information System (INIS)

    Santos, W.R. dos; Abrao, A.

    1980-01-01

    Inorganic exchangers are widely used for adsorption and column partition chromatography. The main difficulty of using commercial alumina (in powder) for column chromatography is related to its packing, and the operations through the column become diffcult and time-consuming; also it turns to be virtually impossible to use large dimension columns. In order to eliminate these problems, a process for the preparation of alumina micro-spheres was developed as an adaptation of a similar process used to prepare nuclear fuel microspheres (UO 2 , ThO 2 ). The flowsheet of this process is presented together with the analytical results of sphericity after calcination, granulometry, density and characterization by X-ray diffractometry. Solubility tests showed that the so-prepared microspheres are well resistant to strong acids and bases; retention tests showed their efficiency, mainly to copper. (C.L.B.) [pt