WorldWideScience
1

Preparation of Nanocomposite GDC/LSCF Cathode Material for IT-SOFC by Induction Plasma Spraying  

British Library Electronic Table of Contents (United Kingdom)

Homogeneous mixtures of Ce0.8Gd0.2O1.9 (GDC) and La0.6Sr0.4Co0.2Fe0.8O3 (LSCF) nanopowders were successfully synthesized using induction plasma by axial injection of a solution. The resulting nanocomposite powders consisted of two kinds of nanopowders with different mass ratio of GDC/LSCF, such as 3/7 and 6/4. The morphological features, crystallinity, and the phases of the synthesized powders were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), local energy-dispersive x-ray spectroscopy (EDS) analysis, and x-ray diffraction (XRD). The nanopowders are almost globular in shape with a diameter smaller than 100?nm and their BET specific areas are around 20?m2?g?1. The GDC and LSCF phases are well distributed in the nanopowders. In addition, suspens...

2011-01-01

2

Composites in the TiC-TiYTZP system  

International Nuclear Information System (INIS)

Ceramic matrix composites in the TiC-Ti, Y-TZP system can be synthesized by the reaction between carbon and the TiO_2-Y_2O_3-ZrO_2 solid solution nanopowder. This method results in the more homogeneous powders than those prepared by the physical mixing of TiC and zirconia s.s. powders. Twelve TiO_2-Y_2O_3-ZrO_2 solid solution nanopowders differing in the proportions of the constituent oxides were prepared by the coprecipitation- calcination route. They were reacted with the pyrolytic carbon evenly distributed within the system. Carbon was introduced by the thermal decomposition of the phenol-formaldehyde resin dissolved in ethyl alcohol and mixed with the zirconia s.s. nanopowder. Reaction was performed in vacuum. Compacts of the composite powders sintered in vacuum give dense materials of evenly distributed TiC inclusions of sizes not surpassing 400 nm. Hardness of such materials ...

2003-09-25

3

Influence of lanthanum (x) concentration on the properties of x/65/35 PLZT electroceramics  

International Nuclear Information System (INIS)

Lead lanthanum zirconate titanate (PLZT) nanopowders with chemical compositions x/65/35 PLZT (x = 6 - 10 mol%) were prepared by sol-gel method. PLZT ceramics was obtained by the conventional sintering method and utilizing the hot pressing method. The investigations of dielectric and ferroelectric measurements of as obtained PLZT ceramics have revealed the influence of lanthanum concentration on the properties of PLZT electroceramics. (author)

2003-09-25

4

Preparation of PbTiO3 nanoceramics based on hydrothermal nanopowders and characterization of their electrical properties  

British Library Electronic Table of Contents (United Kingdom)

In this work, we report the preparation of lead titanate (PT) nanoceramics (with an average grain size of ~200nm in diameter) by using hydrothermal PT nanoparticles as start materials and characterized the dielectric and ferroelectric properties. The dielectric constant of the ceramic was found to be ~180 (at 1kHz) at room temperature and reached a maximum value of 8330 at ~490^oC, suggesting that the Curie temperature of the nanoceramics is consistent with the known value of PT crystals. Ferroelectric domains and hysteresis loops were obtained through piezoelectric force microscopy measurements, which provide direct and clear evidence for the ferroelectricity in the nanoceramic samples.

2010-01-01

5

Surface coating on carbon nanofibers with alumina precursor by different synthesis routes  

British Library Electronic Table of Contents (United Kingdom)

Alumina-reinforced carbon nanofiber nanocomposites were prepared using different routes; powders mixture, colloidal route and sol?gel process followed by spark plasma sintering (SPS). CNFs/xAl2O3 (x = 10?50 vol.%) were prepared through nanopowders mixing in a high-energy attrition milling. The main limitations in the preparation of this kind of nanocomposites are related to the difficulty in obtaining materials with a homogeneous distribution of both phases and the different chemical nature of CNFs and Al2O3, which causes poor interaction between them. A surface coating of CNFs by wet chemical routes with an alumina precursor is proposed as a very effective way to improve the interaction between CNFs and Al2O3. An improvement of 50% in fracture strength was found for similar nanocomposite ...

2011-01-01

6

Synthesis and characterization of undoped and TM (Co, Mn) doped ZnO nanoparticles  

British Library Electronic Table of Contents (United Kingdom)

Antibacterial activity of Transition metals (Mn, Co) doped ZnO nanopowders prepared by a DC thermal plasma method against Escherichia coli and Staphylococcus aureus are investigated. The phase and morphology studies have been carried out by X-ray diffraction, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) respectively. All the samples of the present investigation are found to have hexagonal wurtzite structure and crystallite sizes are found to vary from 25nm to 30nm. Our bacteriological study showed the enhanced antibacterial activity of transition metals doped ZnO nanoparticles than undoped ZnO indicating the great potential of ZnO nanoparticles in relevant clinical and biomedical applications.

2011-01-01

7

Chemically produced nanostructured ODS-lanthanum oxide-tungsten composites sintered by spark plasma  

British Library Electronic Table of Contents (United Kingdom)

High purity W and W-0.9La2O3 (wt.%) nanopowders were produced by a wet chemical route. The precursor was prepared by the reaction of ammonium paratungstate (APT) with lanthanum salt in aqueous solutions. High resolution electron microscopy investigations revealed that the tungstate particles were coated with oxide precipitates. The precursor powder was reduced to tungsten metal with dispersed lanthanum oxide. Powders were consolidated by spark plasma sintering (SPS) at 1300 and 1400degreeC to suppress grain growth during sintering. The final grain size relates to the SPS conditions, i.e. temperature and heating rate, regardless of the starting powder particle size. Scanning electron microscopy revealed that oxide phases were mainly accumulated at grain boundaries while the tungsten matrix ...

2011-01-01

8

An investigation on physical properties of strontium hexaferrite nanopowder synthesized by a sol-gel auto-combustion process with addition of cationic surfactant  

British Library Electronic Table of Contents (United Kingdom)

In this study a novel sol-gel auto-combustion method, using n-decyltrimethylammonium bromide as a cationic surfactant, has been used to synthesize strontium hexaferrite nanocrystalline powder. The dried nitrate-citrate gel, prepared from a solution of ferric nitrate, strontium nitrate, citric acid, trimethylamine and cationic surfactant, exhibited an auto-combustion behavior after ignition in air. The formation reaction temperature, phase identification, crystallites size, particles size distribution and morphology of resultant strontium hexaferrite powder were investigated by DTA/TGA, FTIR, XRD, LPSA, TEM and SEM techniques. The results showed that in presence of the cationic surfactant, the combustion intensity increases and the crystallite size decreases. The crystallite size of stronti...

2007-01-01

9

Nanostructured mesoporous materials for lithium-ion battery applications  

Science.gov (United States)

The Energy crisis happens to be one of the greatest challenges we are facing today. In this view, much effort has been made in developing new, cost effective, environmentally friendly energy conversion and storage devices. The performance of such devices is fundamentally related to material properties. Hence, innovative materials engineering is important in solving the energy crisis problem. One such innovation in materials engineering is porous materials for energy storage. Porous electrode materials for lithium-ion batteries (LIBs) offer a high degree of electrolyte-electrode wettability, thus enhancing the electrochemical activity within the material. Among the porous materials, mesoporous materials draw special attention, owing to shorter diffusion lengths for Li+ and electronic movement. Nanostructured mesoporous materials also offer better packing density compared to their nanostructured counterparts such as nanopowders, nanowires, nanotubes etc., thus ...

2011-05-01

10

Silicon nanopowder as active material for hybrid electrodes of lithium-ion batteries  

British Library Electronic Table of Contents (United Kingdom)

Cycling parameters (reversible specific capacity, first-cycle coulombic efficiency, accumulated irreversible capacity, and reversible capacity retention) of hybrid electrodes based on mechanical mixtures of a silicon nanopowder with KS6 and MAG-20 synthetic graphites and binders of varied nature were subjected to an integrated analysis in comparison with graphite electrodes.

2011-01-01

11

The effect of the precursor nanopowder size on the thermoelectric properties of nanostructured Bi-Sb-Te bulk materials  

International Nuclear Information System (INIS)

This paper presents the effect of precursor powder size on the thermoelectric properties of sintered nanostructured bulk materials. The transport properties of the nanostructured bulk show a dramatic size effect. There are a lower thermal and electrical conductivity for the bulk with smaller nanopowders. The dimensionless figure-of merit values (ZT) of almost all the samples are much lower than those of the list reported data in the paper because the decrease in the thermal conductivity is counteracted by the reduction in the electrical conductivity and the Seebeck coefficient. The combination route of hydro/solvothermal synthesis and spark-plasma-sintering method provide a well controlled way to significantly reduce the thermal conductivity.

2010-12-15

12

Effect of different fuels on the strontium hexaferrite nanopowder synthesized by a surfactant-assisted sol-gel auto-combustion method  

British Library Electronic Table of Contents (United Kingdom)

In this research a sol-gel auto-combustion route has been proposed to synthesize strontium hexaferrite nanopowder, using metal nitrates, ammonia as pH adjusting agent, n-decyltrimethylammonium bromide as a cationic surfactant and different fuels such as citric acid, glycine, acetylacetone and oxalic acid. The formation temperature of strontium hexaferrite and its crystallite size in presence of different fuels were compared together. The results showed the lowest formation temperature as well as the smallest crystallite size in the presence of citric acid as 900degreeC and 37.3nm respectively.

2007-01-01

13
14

BIOINORGANIC CHEMISTRY  

Science.gov (United States)

No abstract prepared.

2002-01-01

15

Preparing the works for the St-Genis roundabout.  

CERN Document Server

Preparing the works for the St-Genis roundabout.

1999-01-01

16

Waste to energy technologies.  

Science.gov (United States)

No abstract prepared.

2010-04-01

18
23

Spark plasma sintered tantalum carbide: Effect of pressure and nano-boron carbide addition on microstructure and mechanical properties  

British Library Electronic Table of Contents (United Kingdom)

TaC and TaC-1wt.% B4C powders were consolidated using spark plasma sintering (SPS) at 1850^oC and varying pressure of 100, 255 and 363MPa. The effect of pressure on the densification and grain size is evaluated. The role of nano-sized B4C as sintering aid and grain growth inhibitor is studied by means of XRD, SEM and high resolution TEM. Fully dense TaC samples were produced at a pressure of 255MPa and higher at 1850^oC. The increasing pressure also resulted in an increase in TaC grain size. Addition of B4C leads to an increase in the density of 100MPa sample from 89% to 97%. B4C nano-powder resists grain growth even at high pressure of 363MPa. The formation of TaB2/Carbon at TaC grain boundaries helps in pinning the grain boundary and inhibiting grain growth. The effect of B4C addition on...

2011-01-01

24

Relation study of different properties for tertiary pulsed electrodeposited Ni-based nanocomposite with Al2O3/Y2O3/CNT nanopowders  

British Library Electronic Table of Contents (United Kingdom)

Electrodeposition of tertiary alumina/yttria/carbon nanotube (Al2O3/Y2O3/CNT) nanocomposite by using pulsed current has been studied in this investigation. Coating process has been performed on nickel sulphate bath and nanostructure of obtained compound layer is examined with high precision figure analysis of SEM nanographs. The effects of process variables, i.e., Y2O3 concentration, treatment time, frequency and duty cycle, have been experimentally studied. Statistical methods are used to achieve the minimum of corrosion rate and average size of nanoparticles. Finally the contribution percentage of different effective factors is revealed and confirmation run shows the validity of obtained results. Also it has been revealed that by changing the size of nanoparticles, corrosion properties o...

2011-01-01

25

Enhanced biosorptive removal of cadmium from aqueous solutions by silicon dioxide nano-powder, heat inactivated and immobilized Aspergillus ustus  

British Library Electronic Table of Contents (United Kingdom)

Heat inactivated Aspergillus ustus (Asp), silicon dioxide-nano-powder (N Si), and silicon dioxide nano-powder-combined-heat inactivated Aspergillus ustus (N Si Asp) were used to study the biosorption of Cd(II) from aqueous solutions via batch equilibrium technique. Surface characterization and immobilization of the fungal cells on silicon dioxide-nano-powder were examined and confirmed by using FT-IR and ESM analysis. Cadmium biosorption processes were investigated under the effect of pH, contact time, sorbent dosage and initial metal concentration. The three examined sorbents were found to exhibit maximum mmolg^-^1 capacity values in pH 7.0. The maximum determined cadmium capacity by silicon dioxide-nano-powder (N Si) (600mmolg^-^1) was found higher than that exhibited by the heat inactiv...

2011-01-01

75

PLZT Ceramics Prepared from Conventional and Microwave Hydrothermal Powders  

CERN Document Server

PLZT Ceramics Prepared from Conventional and Microwave Hydrothermal Powders

1999-01-01

77

A Novel Domperidone Hydrogel: Preparation, Characterization, Pharmacokinetic, and Pharmacodynamic Properties  

UK PubMed Central (United Kingdom)

The purpose of the present study was to prepare a novel domperidone hydrogel. The domperidone dispersion was prepared by the solvent evaporation method. The characteristics of domperidone dispersion...Full Text Available

2011-01-01

105
173

Biological Surface-Active Substance  

International Science & Technology Center (ISTC)

Development of biological preparation with surfactant activity

187
188

Abrasion problems in coal preparation  

Energy Technology Data Exchange (ETDEWEB)

Lining of fused cast basalt tiles is recommended for various pieces of equipment constituting a coal preparation plant.

1981-01-01

189

FFTF operations procedures preparation guide. Revision 2  

Science.gov (United States)

The Guide is intended to provide guidelines for the initial preparation of FFTF Operating Procedures. The Procedures Preparation Guide was developed from the plan presented and approved in the FFTF Reactor Plant Procedures Plan, PC-1, Revision 3.

1976-12-01

190

United ttsCos ur  

Science.gov (United States)

... floppy diskette message preparation - JANAP 128 and DD173 message preparation ... S including JANAP 128, DD173, and ACP 126. ...

2011-05-05

191

The International Reference Preparation of Erythropoietin*  

UK PubMed Central (United Kingdom)

The WHO Expert Committee on Biological Standardization authorized the National Institute for Medical Research to establish an International Reference Preparation of Erythropoietin on the basis of the...Full Text Available

1966-01-01

192

SOLID STATE RESEARCH OF THE APPLIED PHYSICS ...  

Science.gov (United States)

... 10 TIN TELLURIDE Preparation of Tin Telluride Single Crystals ..... 12 ... TIN TELLURIDE Preparation of Tin Telluride Single Crystals ...

1962-07-16

193

Preparation of covalently modified organic-inorganic composite nanoparticles and their interfacial electron transfer researches  

CERN Document Server

Preparation of covalently modified organic-inorganic composite nanoparticles and their interfacial electron transfer researches

1998-01-01

194

Method for preparing thermally cleavable surfactants without deprotonation  

Energy Technology Data Exchange (ETDEWEB)

The present invention describes surfactants of formula (I), ##STR00001## wherein R, R.sub.N, and m are defined herein, processes for their preparation, and methods for their decomposition.

2008-05-27

195

Grit-Blast/Silane (GBS) Aluminum Surface Preparation for ...  

Science.gov (United States)

... GRIT-BLAST/SILANE (GBS) ... GRIT-BLAST/SILANE (GBS) ALUMINUM SURFACE PREPARATION FOR STRUCTURAL ADHESIVE BONDING 5b. ...

2003-04-30

196

Exploration of Cold Extrusion for the Preparation of Enteric Minitablets of Isoniazid  

UK PubMed Central (United Kingdom)

The objective of the present work was to formulate the enteric minitablets of isoniazid by cold extrusion method. The minitablets were prepared using isoniazid, hydroxylpropylmethylcellulose phthalate...Full Text Available

2008-05-01

197

Defense.gov News Article: Task Force Prepares for Horn of ...  

Science.gov (United States)

... After the task force deploys, Joint Forces Command interacts ... and what needs tweaking to better prepare future headquarters staffs, Mungus ...

198

Advanced Technological Education Program: 1999 Awards and Activities  

Science.gov (United States)

... By developing and disseminating educational materials and curricula, supporting the preparation and ... education, such as curriculum or educational materials development, faculty or teacher preparation ...

249

Radiation processing used in forestry in Thailand  

Energy Technology Data Exchange (ETDEWEB)

A summary is presented of research being carried out in Thailand on the preparation of irradiation-impregnated wood.

1981-01-01

275

Obtainment of lanthanum oxide by fractionated precipitation method  

International Nuclear Information System (INIS)

... ammonium compounds benzilic acid chemical preparation lanthanum oxides

1979-01-01

278

Novel Antidrugabuse Peptide  

International Science & Technology Center (ISTC)

Natural Biologically Active HLDF6 Peptide as Potential Preparation for Correction of Different Drugabuse Forms

301

Iron in cookies prepared with fortified flour  

International Nuclear Information System (INIS)

... Italy) Istituto Superiore di Sanita (Italy) 207 p. ENVIRONMENTAL SCIENCES

2009-04-01

319

Ground-temperature measurements  

Energy Technology Data Exchange (ETDEWEB)

Three papers are included. A separate abstract was prepared for each one. (MHR)

1981-01-01

363

Contribution to the radiation preparation of wood-plastic materials. Pt. 7  

International Nuclear Information System (INIS)

... odd nuclei organic compounds radiation effects radioisotopes synthesis

1974-01-01

364

Contribution to the radiation preparation of wood-plastic materials. Pt. 6  

International Nuclear Information System (INIS)

... compounds polymers polyolefins polyvinyls radiation effects SYNTHESIS.

1974-01-01

365

Contribution to the radiation preparation of wood-plastic materials Pt. 3  

International Nuclear Information System (INIS)

... compounds plants radiation effects radioisotopes reaction kinetics trees

1974-01-01

376

Biocontrol Agents of Crops Diseases  

International Science & Technology Center (ISTC)

Scale up of Technology for Production and Application of Rhizobacteria-Based Preparations as Biocontrol Agents of Crop Diseases

394

Use of surface affinity enrichment and cryo-embedding to prepare in vitro reconstituted mitotic chromosomes for EM tomography  

Energy Technology Data Exchange (ETDEWEB)

We present a novel preparation method for studies of in vitro reconstituted mitotic chromosomes from Xenopus laevis egg extracts. This method involves a gentle adsorption of chromosomes from the extracts using surface affinity enrichment, followed by plunge freezing, freeze-substitution and cryo-embedding before examination by EM tomography. For comparison, chromosomes were also prepared by a conventional method, which included immobilization of chromosomes in agarose and a room-temperature dehydration (embedding) protocol. Three-dimensional reconstructions showed that samples prepared with the new method have a greater interconnectivity of sub-structural features and a higher compaction ratio together with an apparently less perturbed chromatin structure than those prepared using the conventional approach. The implications of the new method for the preparation of other difficult ...

2005-07-15

395

Total Synthesis and Evaluation of C26-Hydroxyepothilone D Derivatives for Photoaffinity Labeling of ?-Tubulin  

UK PubMed Central (United Kingdom)

Three photaffinity labeled derivatives of epothilone D were prepared by total synthesis, using efficient novel asymmetric synthesis methods for the preparation of two important synthetic building...Full Text Available

2010-01-01

396

Stability of Plasma Human Immunodeficiency Virus Load in VACUTAINER PPT Plasma Preparation Tubes during Overnight Shipment  

UK PubMed Central (United Kingdom)

VACUTAINER PPT plasma preparation tubes were evaluated to determine the effects of various handling and shipping conditions on plasma human immunodeficiency virus (HIV) load determinations. Plasmas...Full Text Available

2000-01-01

398

Preparation and characterization of anion exchangers from petroleum asphaltites  

British Library Electronic Table of Contents (United Kingdom)

The chloromethylation reaction of an asphaltite and styrene graft copolymer followed by the amination of the chloromethylated products was optimized. New strongly basic anion exchangers with an exchange capacity of 2.5 mg-equiv/g and a mechanical strength of 93% were prepared.

2011-01-01

399

Preparation and Evaluation of Buccal Bioadhesive Films Containing Clotrimazole  

UK PubMed Central (United Kingdom)

Buccal bioadhesive films, releasing topical drugs in the oral cavity at a slow and predetermined rate, provide distinct advantages over traditional dosage forms. The aim of present study was to prepare...Full Text Available

400

Polymer-cushioned bilayers. I. A structural study of various preparation methods using neutron reflectometry.  

UK PubMed Central (United Kingdom)

This neutron reflectometry study evaluates the structures resulting from different methods of preparing polymer-cushioned lipid bilayers. Four different techniques to deposit a dimyristoylphosphatidylcholine...Full Text Available

1999-09-01

401

Catalyst preparation and characterization, session 1  

Energy Technology Data Exchange (ETDEWEB)

The abstracts of all the presentations (1 plenary session, 2 keynotes, 52 oral communications, 496 posters) of the thematic session 1: 'catalyst preparation and characterization' are gathered in the CD-Rom of the conference. The main application described concerns the petroleum industry. (O.M.)

2004-07-01

406

The preparation of carrier-free "2"0"3Pb for medical use  

International Nuclear Information System (INIS)

... bismuth 203 chemical reactions cyclotrons decay helium 3 beams impurities

412

Superconducting properties of metallic superlattices  

Energy Technology Data Exchange (ETDEWEB)

The preparation by sputtering of artificial metallic superlattices is described, as are the results of x-ray structural determinations. Tunneling and resistivity measurements on these materials are reported.

1987-01-01

419

Research workshop on energy conservation through enhanced heat transfer  

Science.gov (United States)

Seven papers were presented at the meeting. A separate abstract was prepared for each paper. (LCL)

1979-10-01

424

Preparation of Papers for AIAA Technical Conferences  

Science.gov (United States)

The estimated parameter covariance matrix is computed from8. ) ( ) 1. 2. T. T. ( ) ( )(. ?. ?. ?. Cov. E. ??. . ?. = . ? ? ? ? ?. ?. = ?. ?. ? ...

448

Fractures in geothermal reservoirs. Special report No. 12  

Energy Technology Data Exchange (ETDEWEB)

Separate abstracts were prepared for thirteen papers. Two papers were abstracted previously for EDB. (MHR)

1982-01-01

463

Computer and Network Security Information  

Science.gov (United States)

Computer And Network Security: Information For Everyone: This presentation was originally prepared as the 14th talk in a series known as "The Programmer's ...

475

Return on investment (ROI) proposal preparation guide  

Energy Technology Data Exchange (ETDEWEB)

The ROI Proposal Preparation Guide is a tool to assist Hanford waste generators in preparing ROI proposal forms for submittal to Department of Energy, Richland Operations Office (DOE/RL) for funding. The guide describes the requirements for submitting an ROI proposal and provides examples of completed ROI forms. The intent is to assist waste generators in identifying projects that meet the criteria, provide information necessary to complete the ROI forms, and submit a proposal that is eligible to receive funding.

1998-10-09

476

Method of preparation of crystal borophosphate with zeolite structure. Sposob polucheniya kristallicheskogo borofosfata tseolitnoj struktury  

Energy Technology Data Exchange (ETDEWEB)

Hydrothermal method for preparing crystal borophosphate with zeolite structure is suggested. To increase absorption capacity and thermal stability of final product, aluminium hydroxide sol, ethylenediamine and ethyl acetate are added to the mixture of crystal boric and concentrated phosphoric acids. Thermal stability of the specimens prepared constitutes 880-950 deg, water absorption capacity is within the limits of 0.30-0.32 cmT/g. 1 table.

1984-12-24

477

ELECTRON MICROSCOPE PREPARATIONS OF RADIOACTIVELY LABELED AEROSOLS  

Science.gov (United States)

A method is described to smear extremely thin layers of nuclear emulsion on labeled electron microscope preparations and to measure the thicknesses of these layers, Without further separation, preparation and emulsion can be observed after exposure and development in an electron microscope. The source of the tracks formed in the emulsion can be exactly identified and the size and structure determined. This method finds applications in dust research and also in the analysis of medical and biological sections. Further information can be obtained about properties of different emulsions. (auth)

1963-04-01

478

Performance of Pd-Ag/Al2O3 catalysts prepared by the selective deposition of Ag onto Pd in acetylene hydrogenation  

British Library Electronic Table of Contents (United Kingdom)

The performance of Ag-promoted Pd/Al2O3 catalysts, which were prepared by the selective deposition of Ag onto Pd using a surface redox (SR) method, during acetylene hydrogenation was compared with that of catalysts prepared by impregnation. The Pd surface was more effectively modified with Ag added by SR, even when small amounts of Ag were added. The catalyst prepared by SR showed a higher ethylene selectivity than the one prepared by impregnation, because SR allowed both the preferential deposition of Ag on the low-coordination sites of Pd and a greater electronic modification of Pd by Ag.

2011-01-01

479

Irradiation of Langmuir-Blodgett multilayer preparations of phospholipids and a fatty acid. Pt. 1; Effect of UV radiation  

Energy Technology Data Exchange (ETDEWEB)

Langmuir-Blodgett (LB) preparations containing stacked monolayers of phospholipids or stearic acid were irradiated with UV light and the electric conductance perpendicular to the planes of the monolayers was measured. There was no observable change of conductance when LB preparations of stearic acid were irradiated. For LB preparations of phospholipids, a rise of conductance, dependent on dose rate, was observed, reaching an equilibrium level after a few hours. After irradiation the conductance fell with a temperature-dependent time constant, and eventually reached a final level a little above the initial value. A three-state model is proposed for the LB phospholipid preparations. This suggests that the absorption of one photon raises a molecule from the ground to an excited state; and the absorption of a second photon carries it into a damaged but repairable or metastable state. (author).

1992-12-01

480

Consolidated silica glass from nanoparticles  

International Nuclear Information System (INIS)

A dense silica glass was prepared by consolidating a highly dispersed silicic acid powder (particle size 1H magic-angle spinning (MAS) NMR confirmed an increase in hydroxyl groups in the sample prepared by SPS relative to that of the conventional SiO2 reference glass. Aside from the comparably high water content, we conclude from the similarity of the IR-reflectance and the 29Si MAS NMR spectra of the SPS sample and the corresponding spectra of the conventionally prepared silica glass, that the short- and medium-range order is virtually the same in both materials. Raman spectroscopy, however, suggests that the number of three- and four-membered rings is significantly smaller in the SPS sample compared to the conventionally prepared sample. Based on these results we conclude that it is possible to prepare glasses by compacting amorphous powders by the SPS process. The SPS process may ...

2008-09-01

481

Metal Nanoparticles Preparation In Supercritical Carbon Dioxide Solutions  

Energy Technology Data Exchange (ETDEWEB)

The novel optical, electronic, and/or magnetic properties of metal and semiconductor nanoparticles have resulted in extensive research on new methods for their preparation. An ideal preparation method would allow the particle size, size distribution, crystallinity, and particle shape to be easily controlled, and would be applicable to a wide variety of material systems. Numerous preparation methods have been reported, each with its inherent advantages and disadvantages; however, an ideal method has yet to emerge. The most widely applied methods for nanoparticle preparation include the sonochemical reduction of organometallic reagents,(1&2) the solvothermal method of Alivisatos,(3) reactions in microemulsions,(4-6) the polyol method (reduction by alcohols),(7-9) and the use of polymer and solgel materials as hosts.(10-13) In addition to these methods, there are a variety of methods that take ...

2004-04-01

482

Layer-by-layer self-assembly of polyimide precursor/layered double hydroxide ultrathin films  

International Nuclear Information System (INIS)

The layer-by-layer (LBL) self-assembly has been extensively used as a simple and effective method for the preparation of polyelectrolyte multilayer films. In this work, we utilized this unique method to prepare polyimide precursor/layered double hydroxide (LDH) ultrathin films. Well-crystallized Co-Al-CO_3 LDH and subsequent anion exchanged Co-Al-NO_3 LDH were prepared and characterized by scanning electron microscopy and X-ray diffraction (XRD). By vigorous shaking of the as-prepared Co-Al-NO_3 LDH, positively charged and exfoliated LDH nanosheets were obtained. Atomic force microscopy and XRD investigations indicated the delamination of LDH nanosheets. The precursor of polyimide, poly(amic acid) tertiary amine salt (PAS) was prepared by the polycondensation of dianhydride and diamine, and subsequent amine salt formation. By using the LBL method, heterogeneous ultrathin films of ...

2010-09-30

483

Radiation induced polymerization of vinyl monomers and their application for preparation of wood-polymer composites  

International Nuclear Information System (INIS)

Polymerizing effects of high energy radiation has been found suitable for preparation of wood-polymer composites. In the present work after evaluating polymer products that have been obtained by irradiation method, wood-polymer composites have been prepared by in situ polymerization of vinyl acetate, acrylic acid and acrylic acid/styrene mixture using two samples of Iranian hardwoods, Beech and Hornbeam. These woods and their composites have been tested for their physical and mechanical properties. The results have shown that chemical bonding between polymer and the cell wall component lead to better strength properties in the composites. (author).

1992-09-01

484

Preparation of 17-amino-22-(4'-azido-3'-"1"2"5iodophenacyl)-17-demethoxygeldanamycin (1): an ansamycin for photoaffinity labeling  

International Nuclear Information System (INIS)

An azido-"1"2"5iodo-ansamycin (1) in the geldanamycin family was prepared in two steps in one reaction vessel from 17-amino-22-(4'-aminophenacyl)-17-demethoxygeldanamycin (3). The title compound was suitable for photoaffinity labeling proteins that interacted with ansamycins. An alternative synthesis is reported for preparation of unlabeled title compound in order to afford practical amounts of (1) for conventional biochemical studies. (Author).

485

Preparation of 17-amino-22-(4'-azido-3'-[sup 125]iodophenacyl)-17-demethoxygeldanamycin (1): an ansamycin for photoaffinity labeling  

Energy Technology Data Exchange (ETDEWEB)

An azido-[sup 125]iodo-ansamycin (1) in the geldanamycin family was prepared in two steps in one reaction vessel from 17-amino-22-(4'-aminophenacyl)-17-demethoxygeldanamycin (3). The title compound was suitable for photoaffinity labeling proteins that interacted with ansamycins. An alternative synthesis is reported for preparation of unlabeled title compound in order to afford practical amounts of (1) for conventional biochemical studies. (Author).

1994-06-01

486

Coal preparation plant condition-based maintenance  

Energy Technology Data Exchange (ETDEWEB)

This report briefly describes the background to colliery engineering maintenance, past experience in machine condition monitoring within coal preparation and the introduction of condition-based maintenance. A role model scheme has been developed for the introduction of condition-based maintenance into coal preparation plants. The report describes the instrumentation and monitoring methods suitable for application to most mineral processing plants, the use of specialist companies to monitor, gather, process and analyse the information and the actions taken by the colliery. Examples of the benefits of operating such a scheme are given in terms of safety, performance and finance. Other problematical aspects of coal processing are examined which have a direct effect on plant condition and availability.

1998-12-31

487

6. Sample preparation for determining pollutants in components of the environment  

International Nuclear Information System (INIS)

Examples are given of reference materials for radionuclide X-ray fluorescence analysis (RXFA) of the environment processed by the National Bureau of Standards and the IAEA. Methods are described used for preparing standard materials for RXFA. For determining air pollutants the sample is prepared by dry or wet mineralization. Water samples have to be preserved prior to analysis. Insoluble components are separated by filtration or centrifugation. Biological materials must be dehydrated and homogenized. Samples of soil, sludges, sediments and solid wastes will sometimes have to be converted into a solution in some cases a leachate will have to be obtained. (ES).

1983-12-01

489

Vitamins and sport.  

UK PubMed Central (United Kingdom)

In a double blind test on 40 men and women high performance fencers the influence of a multivitamin-electrolyte-preparation on reaction time, hit-frequency and neuromuscular irritability was determined....Full Text Available

1978-06-01

491

Positron annihilation study on thin-film composite pervaporation membranes: Correlation between polyamide fine structure and different interfacial polymerization conditions  

British Library Electronic Table of Contents (United Kingdom)

To investigate the variation in the fine structure of polyamide thin-film composite (TFC) membranes prepared via two different interfacial polymerization conditions (IP-I and IP-II), experiments on Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), water contact angle, and positron annihilation spectroscopy (PAS) coupled to a slow positron beam were conducted. Polyamide TFC membranes were prepared via the interfacial polymerization reaction between triethylenetetramine (TETA) and trimesoyl chloride (TMC) on the surface of a modified polyacrylonitrile (mPAN) membrane. Compared with the polyamide TFC membrane prepared via IP-I, the polyamide layer prepared via IP-II showed a shorter S plateau length (thinner thickness), a higher o-Ps intensity I3 value (higher free-volume con...

2010-01-01

497

DISTORTION OF A MAGNETIC FIELD BY THE MOTION OF A ...  

Science.gov (United States)

... No. 52. Metal Complexew-I. Preparation and Physical Properties of Transition Metal Complexes of 6-Mercaptopurine and ,-Mercapto-6, 7-Diphenyl ...

1965-06-01

499

AN EVALUATION OF AN IMPORTANT ADVANCE IN ...  

Science.gov (United States)

... No. 52. Metal Complexes-I. Preparation and Physical Properties of Transition Metal Complexes of 6-Mercaptopurine and 4-Mercapto-6, 7-Diphenyl ...

1965-03-01

500

A novel single-step synthesis of N-doped TiO"2 via a sonochemical method  

British Library Electronic Table of Contents (United Kingdom)

A novel single-step synthetic method for the preparation of anatase N-doped TiO"2 nanocrystalline at low temperature has been devoleped. The N-doped anatase TiO"2 nanoparticles were synthesized by sonication of the solution of tetraisopropyl titanium and urea in water and isopropyl alcohol at 80^oC for 150min. The as-prepared sample was characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and UV-vis absorption spectrum. The product structure depends on the reaction temperature and reaction time. The photocatalytic activity of the as-prepared photocatalyst was evaluated via the photodegradation of an azo dye direct sky blue 5B. The results show that the N-doped TiO"2 nanocrystalline prepared via sonication exhibit an excellent photocatalytic...

2011-01-01