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1

Nanocrystal indium doped zinc oxide prepared by spray pyrolysis method  

Microsoft Academic Search

Thin films of indium-doped zinc oxide have been prepared by spray pyrolysis of the methanol solution of zinc acetate on heated substrates. As prepared films show hexagonal wurtzite nanocrystal structure. The films have 90 % transmission for wavelength more than 550 nm, but the conductivity depends from the indium doping. Thickness of 500 nm of the films was estimated from

A. Tanusevski; M. Ristova; M. Ristov; V. Georgieva

2007-01-01

2

Synthesis and characterization of nano-sized MgB 2 powder by spray pyrolysis method  

NASA Astrophysics Data System (ADS)

The nano-sized MgB 2 powder was prepared by spray pyrolysis method in order to improve its flux pinning properties by increasing the number of grain boundaries. MgB 2 powder was synthesized using spray pyrolysis technique followed by a post-annealing process without excessive magnesium addition. The feed solution was prepared by dissolving the correct amounts of Boric acid and Magnesium acetate tetrahydrate into distillated water and ethanol solution and the overall concentration were fixed at 0.1 mol/L. During the decomposition, 96% Ar-4% H 2 was used as carrier gas. The collected powders were characterized by X-ray diffraction, scanning electron microscopy, particle size analyzer, and physical property measurement system. The particles prepared by spray pyrolysis showed spherical morphology and uniform distribution with the average size of 1 ?m. The onset of superconducting Tc for synthesized MgB 2 powder was around 38 K.

Park, S. C.; Chung, J.-K.; Lim, Y.-J.; Kang, S. G.; Song, K.-J.; Kim, C.-J.; Kim, C. J.

2008-09-01

3

Method to synthesize and produce thin films by spray pyrolysis  

DOEpatents

Forming a film by spraying onto a heated substrate an atomized solution containing the appropriate salt of a constituent element of the film and a highly soluble (i.e., greater than 1 M) organic acid in sufficient amount to reduce the oxidation state of at least one solute element of the spray solution after contacting the heated substrate.

Squillante, Michael R. (Waltham, MA)

1982-06-22

4

Method to synthesize and produce thin films by spray pyrolysis  

DOEpatents

Forming a film by spraying onto a heated substrate an atomized solution containing the appropriate salt of a constituent element of the film and a reducing agent at a concentration greater than 1 M and greater than 10 times the stoichiometric amount of reducing agent.

Turcotte, Richard L. (Malden, MA)

1982-07-06

5

Mn doped ZnO nanostructured thin films prepared by ultrasonic spray pyrolysis method  

NASA Astrophysics Data System (ADS)

Mn-doped ZnO thin films with different percentage of Mn content (0, 1, 3 and 5 at.%) and substrate temperature of 350 °C, were deposited by a simple ultrasonic spray pyrolysis method under atmospheric pressure. We have studied the structural and optical properties by using X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR) and ultra-violet visible near infrared (UV-Vis-NIR) spectroscopy. The lattice parameters calculated for the Mn-doped ZnO from XRD pattern were found to be slightly larger than those of the undoped ZnO, which indicate substitution of Mn in ZnO lattice. Compared with the Raman spectra for ZnO pure films, the Mn-doping effect on the spectra is revealed by the presence of additional peak around 524 cm-1 due to Mn incorporation. With increasing Mn doping the optical band gap increases indicating the Burstein-Moss effect.

Baghdad, R.; Kharroubi, B.; Abdiche, A.; Bousmaha, M.; Bezzerrouk, M. A.; Zeinert, A.; El Marssi, M.; Zellama, K.

2012-10-01

6

Electrochromic properties of nano-structured nickel oxide thin film prepared by spray pyrolysis method  

NASA Astrophysics Data System (ADS)

In this study, we present a simple method to improve the electrochromic properties of a nickel oxide thin film. The method involves a three-step process—(a) conducting indium tin oxide (ITO) nano-particles were first sprayed onto a conducting substrate to form a porous nano-structured ITO layer, (b) nickel oxide film was then deposited onto the nano-structured ITO layer by a spray pyrolysis technique, and (c) the substrate, ITO nano-particles layer and nickel oxide film were annealed at high temperature of 300 °C to improve adhesion of these three layers. The microstructure of the resulting electrochromic cell was investigated using scanning electron microscopy. It is evident that the nickel oxide film covers the surface of the ITO nano-particle layer and forms a nano-structured nickel oxide (NSNO) film. The switching time and contrast were characterized by Autolab PGSTAT12 potentiostat and Jasco V-570 spectrophotometer. The results suggest that the transmittance contrast and switching time of NSNO are slightly superior to those of a conventional nickel oxide (CNO) film. However, the cycling durability of NSNO can be much better than that of CNO.

Lin, Sheng-Hui; Chen, Fu-Rong; Kai, Ji-Jung

2008-01-01

7

Particle morphology and electrochemical performances of spinel LiMn 2O 4 powders synthesized using ultrasonic spray pyrolysis method  

Microsoft Academic Search

Spinel lithium manganese oxide LiMn2O4 powders with submicron, narrow-size-distribution, and phase-pure particles were synthesized by ultrasonic spray pyrolysis method from an aqueous lithium nitrate and manganese acetate solution. A tubular furnace with six independently controlled heating zones was used in this synthesis. The effect of axial temperature profile in the aerosol flow reactor on the particle properties of as-prepared LiMn2O4

I Taniguchi; C. K Lim; D Song; M Wakihara

2002-01-01

8

Structural and magnetic characterization of Mn-doped ZnO films grown by spray pyrolysis method  

Microsoft Academic Search

Mn-doped ZnO films on Si substrate could be grown by the spray pyrolysis method at 500°C under an air atmosphere. Although the orientation (0002) peak intensity became small with increasing Mn concentration, the lattice constant of the c-axis expanded monotonously with increasing Mn concentration. This indicated that the Mn ion was understood to have occupied the Zn site without changing

Kenji Yoshino; Satoshi Oyama; Minoru Yoneta; Tomoyasu Taniyama

2008-01-01

9

Production and characterization of submicron hematite (?-FeO) particles by ultrasonic spray pyrolysis method  

NASA Astrophysics Data System (ADS)

The ultrasonic spray pyrolysis (USP) method has been used to prepare submicron hematite (?-FeO) particles using two different industrial pickling solutions of iron chloride (41 g/L FeCl and 54 g/L FeCl) Particles were obtained by thermal decomposition of generated aerosols from precursor solutions using 1.7 MHz ultrasonic atomizer. Reaction temperature was set up at 800 °C and aerosol droplets were carried into the heated zone by 0.7 L/min air flow rate. X-Ray Diffraction (XRD) studies were used to determine the crystal structure and crystallite size of the particles. Results indicate that patterns correspond to hematite phase with rhombohedral crystal structure (space group: R3c). The crystallite sizes of particles prepared from FeCl and FeCl solutions that were calculated from Scherrer equation are 59 and 33 nm, respectively. Scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) investigations give detailed information about particle size, morphology and composition. SEM micrographs show that hematite nanoparticles aggregate and formed spherical secondary particles in submicron range.

K?rc?, Burak; Ebin, Burçak; Gürmen, Sebahattin

2013-12-01

10

Synthesis and Photocatalytic Property of ZnO nanoparticles Prepared by Spray-Pyrolysis Method  

NASA Astrophysics Data System (ADS)

In this research, ZnO nanoparticles were synthesized by spray-pyrolysis method using the zinc acetate dihydrate as starting material at synthesis temperature of 900°C with various concentrations (0.01, 0.1, 1.0 M, respectively). The physico-chemical property of synthesized ZnO nanoparticles was characterized by XRD, SEM, FT-IR, and UV-vis spectroscopy. The synthesized ZnO nanoparticles indicated particle size with two-type shape. With increased precursor concentration, the ZnO nanoparticles were shown not only increasing from 0.8 to 1.5 ?m at primary particles but also similar tendency (15 to 35 nm) at secondary particles. Also, the photocatalytic activities of ZnO synthesized in different precursor concentration was evaluated by removal rate of methyleneblue (MB) under UV irradiation (365 nm) at room temperature. The results showed that the photocatalytic efficiency of ZnO nanoparticles was enhanced by increased precursor concentration.

Lee, Sang Duck; Nam, Sang-Hun; Kim, Myoung-Hwa; Boo, Jin-Hyo

11

Spray Drying, Spray Pyrolysis and Spray Freeze Drying  

Microsoft Academic Search

\\u000a In conventional spray pyrolysis (CSP or simply SP), a solution is sprayed into a carrier gas forming small droplets; owing\\u000a to the high temperature of the surrounding gas, the solvent is vaporized and the solute is precipitated on and within the\\u000a droplets. If the air temperature is high enough, solute is decomposed to form final solid particles. A schematic diagram

M. Eslamian; N. Ashgriz

12

Synthesis of spherical LiMn 2O 4 microparticles by a combination of spray pyrolysis and drying method  

Microsoft Academic Search

Lithium manganese oxide (LiMn2O4) has been synthesized by a spray pyrolysis method from the precursor solution; LiNO3 and Mn(NO3)2·6H2O were stoichiometrically dissolved into distilled water. The synthesized LiMn2O4 particles exhibited a pure cubic spinel structure in the X-ray diffraction (XRD) patterns, however they were spherical hollow spheres for various concentrations of precursor solution. Thus, the as-prepared LiMn2O4 particles were then

Izumi Taniguchi; Norifumi Fukuda; Muxina Konarova

2008-01-01

13

Investigation of the properties of nanostructured Li-doped NiO films using the modified spray pyrolysis method  

PubMed Central

The lithium-doped nickel oxide (L-NiO) films were synthetized using the modified spray pyrolysis method with a two-step grown process. By observing the spectra of X-ray photoemission spectroscopy of L-NiO films, the intensity of Ni 2p3/2 peak of Ni3+ bonding state increases with increasing Li concentration that causes the decrease of transparency and resistivity. The L-NiO films with optimum characteristics were obtained at Li = 8 at%, where a p-type resistivity of 4.1 × 10?1 ? cm and optical transparency above 76% in the visible region are achieved.

2013-01-01

14

Carbon Precursor Dependence of Carbon Nanofibers Synthesized by Catalyst-Free Ultrasonic Spray-Pyrolysis Method  

NASA Astrophysics Data System (ADS)

In this paper, we report the growth of carbon nanofibers (CNFs) by catalyst-free ultrasonic spray-pyrolysis of methanol, ethanol and 2-propanol. We found that the morphology of carbon deposition on the substrate strongly depended on the position of the substrate in the reaction tube and the carbon source species. When ethanol and 2-propanol were used as the carbon source, a slightly hollow structure CNFs were formed downstream in the reaction tube, whereas when the carbon source was methanol, an amorphous structure CNFs were formed at the center of the reaction tube. We consider the difference in CNFs growth between the alcohol types is presence of alkyl groups in alcohol.

Bao, Jianfeng; Kishi, Naoki; Soga, Tetsuo

2013-10-01

15

Producing Quantum Dots by Spray Pyrolysis  

NASA Technical Reports Server (NTRS)

An improved process for making nanocrystallites, commonly denoted quantum dots (QDs), is based on spray pyrolysis. Unlike the process used heretofore, the improved process is amenable to mass production of either passivated or non-passivated QDs, with computer control to ensure near uniformity of size.

Banger, Kulbinder; Jin, Michael H.; Hepp, Aloysius

2006-01-01

16

Ceramic powder synthesis by spray pyrolysis  

Microsoft Academic Search

A variety of spray pyrolysis (SP) techniques have been developed to directly produce ceramic powders from solutions. This paper reviews the current status of these processes in terms of the process parameters that enable the formation of particles with controlled morphology and composition. A model incorporating solute diffusion in the droplet and solvent evaporation from the droplet surface is presented

Gary L. Messing; Shi-Chang Zhang; Gopal V. Jayanthi

1993-01-01

17

A comparative study of dip coating and spray pyrolysis methods for synthesizing ITO nanolayers by using Ag colloidal sol  

NASA Astrophysics Data System (ADS)

Indium tin oxide (ITO) films were deposited on glass substrates by dip-coating and thermal pyrolysis methods. Sn (IV) is often used in the spray method as a precursor salt, but in this research we have employed a new procedure that uses Sn (II) and In(NO3)3 for preparation of transparent conductive thin films. Then, colloidal Ag was deposited on the ITO layers in order to compare the two synthesis methods, and the structural and electrical properties of the resultant films were investigated by FESEM, XRD, and four-terminal resistometry. The obtained films are polycrystalline with a preferred orientation of (200). The XRD patterns of the films indicate that in both films, the Sn phase is crystallized separately from In2O3. The presence of a Sn peak and the overall low intensity of XRD peaks suggest relative crystallization of ITO structure. For this reason, Ag films were deposited by dip coating method using a colloidal sol. By analyzing the XRD patterns of Ag-ITO films after eliminating the Sn peak, the increased intensity of the peaks confirmed the relatively good crystallization of the ITO films. The results show that the films with a sheet resistance as low as 2 × 10-2 ?·cm, which is beneficial for solar cells, were achieved.

Rajabi, Negar; Heshmatpour, Felora; Malekfar, Rasoul; Bahari-Poor, Hamid-Reza; Abyar, Selda

2014-01-01

18

Nanocrystalline LiMn 2O 4 thin film cathode material prepared by polymer spray pyrolysis method for Li-ion battery  

Microsoft Academic Search

Nanocrystalline cubic spinel lithium manganese oxide thin film was prepared by a polymer spray pyrolysis method using lithium acetate and manganese acetate precursor solution and polyethylene glycol-4000 as a polymeric binder. The substrate temperature was selected from the thermogravimetric analysis by finding the complete crystallization temperature of LiMn2O4 precursor sample. The deposited LiMn2O4 thin films were annealed at 450, 500

S. N. Karthick; S. Richard Prabhu Gnanakan; A. Subramania; Hee-Je Kim

2010-01-01

19

The influence of urea on the formation process of BiPbSrCaCuO superconducting ceramics synthesized by spray pyrolysis method  

Microsoft Academic Search

The influence of urea on the formation process in the Bi–Pb–Sr–Ca–Cu–O system, as well as, on the final high Tc phase content and morphology of the powders obtained by spray pyrolysis method was studied. The process involves aerosol formation from common nitrate solutions (with and without urea addition) using ultrasonic atomizer operated at 1.7 MHz and control over aerosol decomposition

L Man?i?; O Miloševi?; B Marinkovi?; M. F de Silva Lopes; F Rizzo

2000-01-01

20

Thin Film Electrode Materials Li4Ti5O12 and LiCoO2 Prepared by Spray Pyrolysis Method  

NASA Astrophysics Data System (ADS)

The Li4Ti5O12 and the LiCoO2 have been considered as promising candidates of electrode materials for all-solid-state lithium secondary batteries. The spray pyrolysis method is a useful economical technique to prepare various thicknesses of oxide films though have not been intensively studied for fabrication of thin film lithium batteries. Thin films of Li4Ti5O12 and LiCoO2 electrode materials about 100-400 nm were prepared on quartz and gold substrates by the spray pyrolysis method by using Liacac and, TiO(acac)4 or Co(acac)3 with DMF solvent as starting materials. Electric properties as electrode materials for lithium batteries were estimated by using 3 probe liquid cells with liquid electrolyte LiPF6 in EC-DMC and Li metal as reference and counter electrodes. Structure and morphology of the films were investigated by XRD and SEM. Crystalline Li4Ti5O12 and LiCoO2 thin films were found to be prepared over 700 °C of substrate temperature. Cyclic voltammograms of the Li4Ti5O12 electrode thin films showed sharp oxidation and reduction peaks around 1.6 and 1.5 V, respectively. Charge-discharge curves for both Li4Ti5O12 and LiCoO2 electrode thin films showed discharge plateaus around 1.4 and 3.8 V with about 80 mAhg-1 of capacity. These results showed that these electrode thin films prepared by the spray pyrolysis method are electrochemically active and spray pyrolysis method is a promising technique to prepare thin film electrode materials.

Takahashi, M.; Tani, J.; Kido, H.; Hayashi, A.; Tadanaga, K.; Tatsumisago, M.

2011-05-01

21

Barium strontium titanate powders prepared by spray pyrolysis  

Microsoft Academic Search

Ultasonic spray pyrolysis (SP) has been investigated for the production of the barium strontium titanate (BST) powders from the polymeric precursors. The processing parameters, such as flux of aerosol and temperature profile inside the furnace, were optimized to obtain single phase BST. The powders were characterized by the methods of X-ray diffraction analysis, SEM, EDS and TEM. The obtained powders

G. Brankovi?; Z. Brankovi?; M. S. Góes; C. O. Paiva-Santos; M. Cilense; J. A. Varela; E. Longo

2005-01-01

22

Spray Pyrolysis of CuIn(S,Se)2 Solar Cells with 5.9% Efficiency: A Method to Prevent Mo Oxidation in Ambient Atmosphere.  

PubMed

Direct spray pyrolysis to form CuInS2 (CIS) on molybdenum substrate in ambient environment has been a challenge because of the ease of Mo oxidation at low temperatures. MoO2 formation affects the wettability of precursor solution during spray pyrolysis, which degrades the uniformity of CIS film and acts as a resistive layer for carrier transport. In this paper, Mo oxidation was prevented by using excess sulfur in the precursor solution under a gradual heating and spray process. A thin precursor layer was initially deposited as a barrier layer to prevent oxygen adsorption on Mo surface before the temperature was increased further to form polycrystalline CuInS2. The CuIn(S,Se)2 (CISSe) device fabricated from selenization of the spray-pyrolyzed CIS film exhibited a power conversion efficiency (PCE) of 5.9%. The simple spray method proposed here can be used to deposit a variety of Cu-based chalcopyrite precursor to produce high-quality thin film solar cells. PMID:24697706

Ho, John C W; Zhang, Tianliang; Lee, Kian Keat; Batabyal, Sudip K; Tok, Alfred I Y; Wong, Lydia H

2014-05-14

23

Structural, optical and magnetic properties of Cr doped ZnO microrods prepared by spray pyrolysis method  

NASA Astrophysics Data System (ADS)

A series of Cr-doped ZnO micro-rod arrays were fabricated by a spray pyrolysis method. X-ray diffraction patterns of the samples showed that the undoped and Cr-doped ZnO microrods exhibit hexagonal crystal structure. Surface morphology analysis of the samples has revealed that pure ZnO sample has a hexagonal microrod morphology. From X-ray photoelectron spectroscopy studies, the Cr 2p3/2 binding energy is found to be 577.3 eV indicating that the electron binding energy of the Cr in ZnO is almost the same as the binding energy of Cr 3+ states in Cr 2O 3. The optical band gap Eg decreases slightly from 3.26 to 3.15 eV with the increase of actual Cr molar fraction from x = 0.00 to 0.046 in ZnO. Photoluminescence studies at 10 K show that the incorporation of chromium leads to a relative increase of deep level band intensity. It was also observed that Cr doped samples clearly showed ferromagnetic behavior; however, 2.5 at.% Cr doped ZnO showed remnant magnetization higher than that of 1.1 at.% and 4.6 at.% Cr doped samples, while 4.6 at.% Cr doped ZnO samples had a coercive field higher than the other dopings.

Y?lmaz, S.; Parlak, M.; Özcan, ?.; Altunba?, M.; McGlynn, E.; Bacaks?z, E.

2011-09-01

24

[Study of the physical properties of SnS thin films deposited by ultrasonic spray pyrolysis method].  

PubMed

In the present paper, SnS thin films were deposited by ultrasonic spray pyrolysis method. The influence of the three different precursor concentrations on the properties of SnS thin films was compared. XRD shows that when precursor solution is thiourea (0.5 mol x L(-1)) + tin tetrachloride (0.5 mol x L(-1)) + deionized water, there are SnS and SnO2 mixed phases; when precursor solution is thiourea (0.6 mol x L(-1)) + tin tetrachloride (0.5 mol x L(-1)) + deionized water, SnS phase is the dominant diffraction peak, although a certain amount of SnO2 phase is contained; when precursor solution is thiourea (0.7 mol x L(-1)) + tin tetrachloride (0.5 mol x L(-1)) + deionized water, thin film after being annealed is single SnS thin film with orthorhombic structure. SEM shows that films are uniform and dense. Furthermore, the particles of films are bigger when thiourea concentration is higher. Transmittance spectrum shows that the influence of precursor concentration on transmittance of thin films is less. Dark I-V and C-V tests of the devices show that junction characteristics of the devices were similar when prepared by three different concentrations of precursor solution, and as the thiourea concentration is higher, the carrier concentration is relatively larger. PMID:22250530

Tang, Ping; Li, Bing; Lei, Zhi; Feng, Liang-Huan; Cai, Ya-Ping; Zheng, Jia-Gui; Zhang, Jing-Quan; Li, Wei; Wu, Li-Li; Zeng, Guang-Gen

2011-10-01

25

Mn doping effect on the structural properties of ZnO-nanostructured films deposited by the ultrasonic spray pyrolysis method  

NASA Astrophysics Data System (ADS)

Mn-doped ZnO thin films with different percentages of Mn content (0, 1, 3 and 5 at%) and substrate temperature of 350 °C, were deposited by a simple ultrasonic spray pyrolysis method under atmospheric pressure. The chemical compositions and surface morphologies were examined by dispersive x-ray spectroscopy and scanning electron microscopy micrographs. We have studied the structural and optical properties by using x-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy and ultra-violet visible near-infrared spectroscopy. The lattice parameters calculated for the Mn-doped ZnO from XRD pattern were found to be slightly larger than those of the undoped ZnO, which indicate substitution of Mn in the ZnO lattice. Compared with the Raman spectra for ZnO pure films, the Mn-doping effect on the spectra is revealed by the presence of an additional peak about 524 cm-1 due to Mn incorporation. With increasing Mn doping the optical band gap increases indicating the Burstein-Moss effect.

Kharroubi, B.; Baghdad, R.; Abdiche, A.; Bousmaha, M.; Bousquet, M.; Zeinert, A.; El Marssi, M.; Zellama, K.; Hamzaoui, S.

2012-07-01

26

Magnetoresistance properties of MgB2 thick films on YSZ substrate using spray pyrolysis method  

NASA Astrophysics Data System (ADS)

The MgB2 thick films have been fabricated on the polycrystalline YSZ substrates using spray pyrlosis technique. Structural/microstructural, electrical and magnetic properties were investigated by XRD, SEM-EDX and R-T measurements. The films fabricated showed dense and homogenous structural formation with strong grain connections. The electrical properties of MgB2 thick films were investigated under different magnetic fields. It was seen that resistive transition broadened with increasing the applied magnetic fields. It was believed that the broadening is due to the thermally activated flux flow (TAFF). The activation energy, U(H), of the MgB2 films was calculated using Arhenius law.

Altin, S.; Aksan, M. A.; Yakinci, Z. D.; Özabaci, M.; Balci, Y.; Yakinci, M. E.

2009-03-01

27

Copper sulfides by chemical spray pyrolysis process  

NASA Astrophysics Data System (ADS)

The chemistry of formation of copper sulfide and copper indium disulfide films by the chemical spray pyrolysis process has been investigated. It was established that the formation of copper sulfide films by the spray process of water solutions of CuCl2 and SC(NH2)2 passes through the stage of formation of intermediate complex compound Cu(SCN2H4)Cl·H2O in the initial solution. Thermal behaviour studies in air exhibit rearrangement of the complex at temperatures higher than 210 °C with formation of copper sulfide. Copper oxide is the decomposition product at temperatures higher than 700 °C in air. CuInS2 is formed by the reaction between copper and indium sulfides.

Krunks, M.; Mellikov, E.; Bijakina, O.

1997-01-01

28

Improved superconducting properties of MgB2 thin films fabricated by ultrasonic spray pyrolysis method at high temperature  

NASA Astrophysics Data System (ADS)

High quality MgB2 superconducting thin films have been successfully prepared by 2.4 MHz ultrasonic spray pyrolysis (USP) system on single crystal Al2O3 (0 0 1) substrates. The microstructure, electrical and magnetic properties of approximately 500-600 nm thick films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) in conjunction with the energy dispersive X-ray analysis (EDX), resistance versus temperature (R-T) and magnetization measurements (M-H) under different magnetic fields and transport critical current density (Jc). Films were first heat treated in situ in the spraying chamber with an extra Mg powder during deposition to compensate excess evaporation of Mg from the films and then additionally heat treated in Ar atmosphere at 700 °C for a short time. According to the results obtained, orientation on any particular direction for the crystal growth was not seen. Homogeneous, highly dense and highly smooth surface morphology and low resistance have been achieved under optimum conditions. Optimally treated films exhibited relatively high transport critical current density of 2.37 × 105 A cm-2. These results have been also compared with the Jcmag results calculated from the M-H curves. The electrical resistance property of the best samples was obtained to be 39.5 and 37.4 K for Tc and Tzero, respectively.

Yakinci, M. Eyyuphan; Yakinci, Z. Deniz; Aksan, M. Ali; Balci, Yakup

2012-12-01

29

Aerosol spray pyrolysis & solution phase synthesis of nanostructures  

NASA Astrophysics Data System (ADS)

This dissertation focuses on the synthesis of nanomaterials by both solution phase and gas phase methods. By the solution phase method, we demonstrate the synthesis of Au/CdS binary hybrid nanoparticles and the Au-induced growth of CdS nanorods. At higher reaction temperature, extremely uniform CdS nanorods were obtained. The size of the Au seed nanoparticles has an important influence on the length and diameter of the nanorods. In addition, preparation of peanut-like FePt-CdS hybrid nanoparticles by spontaneous epitaxial nucleation and growth of CdS onto FePt-seed nanoparticles in high-temperature organic solution is reported. The FePt-CdS hybrid nanoparticles reported here are an example of a bifunctional nanomaterial that combines size-dependent magnetic and optical properties. In the gas phase method, a spray pyrolysis aerosol synthesis method was used to produce tellurium dioxide nanoparticles and zinc sulfide nanoparticles. Tellurite glasses (amorphous TeO2 based materials) have two useful optical properties, high refractive index and high optical nonlinearity, that make them attractive for a range of applications. In the work presented here, TeO2 nanoparticles were prepared by spray pyrolysis of an aqueous solution of telluric acid, Te(OH)6. This laboratory-scale process is capable of producing up to 80 mg/hr of amorphous TeO2-nanoparticles with primary particle diameters from 10 to 40 nm, and allows their synthesis in significant quantities from an inexpensive and environmentally friendly precursor. Furthermore, both Er3+ doped and Er3+ and Yb3+ co-doped tellurium dioxide nanoparticles were synthesized by spray pyrolysis of an aqueous mixture of telluric acid with erbium/ytterbium salts, which exhibit the infrared to green visible upconversion phenomena. ZnS nanoparticles (NPs) were prepared by spray pyrolysis using zinc diethyldithiocarbamate as a single-source precursor. The home-built scanning mobility particle spectrometer (SMPS) is a useful tool for online measurement of the as-produced nanoparticle size distribution in the gas phase. These SMPS results show clearly the transition of precursor aerosol from liquid to vapor phase and that nanoparticle production in the reactor occurs via gas-to-particle conversion. Applicable characterization methods were employed to characterize and to investigate the optical properties of the various materials described in this dissertation.

Zhang, Hongwang

30

Effect of nickel doping on physical properties of zinc oxide thin films prepared by the spray pyrolysis method  

NASA Astrophysics Data System (ADS)

In this study, undoped and nickel-doped zinc oxide thin films (ZnO:Ni) were deposited on glass substrates using a spray pyrolysis technique. The effects of the Zn concentration in the initial solution and the substrate temperature on the physical properties of the thin films are studied. The results show that the optimum Zn concentration and substrate temperature for preparation of basic undoped ZnO films with n-type conductivity and high optical transparency are 0.02 M and 350 °C, respectively. Then, by using these optimized deposition parameters, nickel-doped zinc oxide films are prepared. Surface morphology and crystalline structure of the films are investigated by atomic force microscopy (AFM) and X-ray diffractometer. X-ray diffraction (XRD) patterns show that the films are polycrystalline. The structural analysis shows that all the samples have a hexagonal structure. The crystallite size and the preferred orientation were calculated from the XRD data. From AFM investigations, the surface morphology of the nanostructured films is found to depend on the concentration of Ni. Optical measurements have shown that an increase in the Ni doping results in a reduction in the optical transmission of the layer, but it remains higher than 80% for Ni doping greater than 8 wt%. At the same time, the optical gap increases from 3.4 to 4 eV when the Ni ratio increases. The electrical measurements show that the resistance of the films varies with the duration of pulverization and the nickel content of the film. Low values for the electrical resistivity (around 103 ? cm) were obtained for Ni-doped ZnO thin films.

Jlassi, M.; Sta, I.; Hajji, M.; Ezzaouia, H.

2014-05-01

31

Band positions and photoelectrochemical properties of Cu2ZnSnS4 thin films by the ultrasonic spray pyrolysis method  

NASA Astrophysics Data System (ADS)

Cu2ZnSnS4 (CZTS) films were prepared by ultrasonic spray pyrolysis on FTO (SnO2?:?F on glass) substrates. The effect of substrate temperatures on the phases, morphologies and photoelectrochemical properties of CZTS films was investigated. X-ray diffraction, Raman spectrum and energy-dispersive spectrometry were used to confirm the phases of the CZTS films. The samples at 400 and 450 °C exhibited a higher photocurrent than the samples at 350 and 500 °C. Moreover, the band positions of CZTS were measured by a facile Mott-Schottky method for the first time. Different from the previous calculation and experimental data, the conduction band position of CZTS was 0.26 eV higher than that of CdS. The results can explain well the low open circuit voltage of a CZTS-based solar cell and offer guidance to improving CZTS solar cells.

Huang, Sheng; Luo, Wenjun; Zou, Zhigang

2013-06-01

32

Preparation of ZnO-TiO2 Composite Fine Particles Using the Ultrasonic Spray Pyrolysis Method and Their Characteristics on Ultraviolet Cutoff  

Microsoft Academic Search

ZnO-TiO2 composite fine particles were prepared by ultrasonic spray pyrolysis of TiO2 (anatase) particles suspended in Zn(NO3)2 aqueous solution. The morphology and the crystalline phases of fine particles were studied with varying nebulizing solution compositions, reactor temperature, and nitrogen carrier gas flow rate. The aggregate particles produced were spheres of ZnO (wurtzite structure) and TiO2 (anatase), whose diameters ranged from

Kentaro Ohshima; Keiichi Tsuto; Kikuo Okuyama; Noboru Tohge

1993-01-01

33

Nano-structured SnO 2-carbon composites obtained by in situ spray pyrolysis method as anodes in lithium batteries  

Microsoft Academic Search

In this paper, we report on a series of SnO2-carbon nano-composites synthesized by in situ spray pyrolysis of a solution of SnCl2·2H2O and sucrose at 700°C. The process results in super fine nanocrystalline SnO2, which is homogeneously distributed inside the amorphous carbon matrix. The SnO2 was revealed as a structure of broken hollow spheres with porosity on both the inside

Ling Yuan; K. Konstantinov; G. X. Wang; H. K. Liu; S. X. Dou

2005-01-01

34

Structural, electrical, optical, thermoelectrical and photoconductivity properties of the SnO2–Al2O3 binary transparent conducting films deposited by the spray pyrolysis method  

Microsoft Academic Search

In this paper, the SnO2–Al2O3 binary thin-film system has been deposited on a glass substrate by the spray pyrolysis technique. The effect of aluminum concentration on the structural, electrical, thermoelectrical, optical and photoconductivity properties of films was studied. The [Al]\\/[Sn] atomic ratio was in the range 0–100 at.% in solution. X-ray diffraction analysis shows that all films with different doping

F Moharrami; M-M Bagheri-Mohagheghi; H Azimi-Juybari; M Shokooh-Saremi

2012-01-01

35

Direct synthesis of highly crystalline transparent conducting oxide nanoparticles by low pressure spray pyrolysis  

Microsoft Academic Search

In this article, we firstly reported a general preparation method for the production of highly crystallized and single crystalline transparent conducting oxide (TCO) nanoparticles: tin-doped indium oxide (ITO), zinc-doped indium oxide (IZO), aluminum-doped zinc oxide (AZO), and gallium-doped zinc oxide (GZO). Low-pressure spray pyrolysis was applied by means of a modified-atomizer and preheated carrier gas. The effects of pyrolysis pressure,

Takashi Ogi; Darmawan Hidayat; Ferry Iskandar; Agus Purwanto; Kikuo Okuyama

2009-01-01

36

Comparative study of nanocrystalline Zr{sub 0.85}Ce{sub 0.15}O{sub 2} powders synthesised by spray-pyrolysis and gel-combustion methods  

SciTech Connect

Zr{sub 0.85}Ce{sub 0.15}O{sub 2} nanopowders synthesised by gel-combustion and spray-pyrolysis methods were comparatively studied by means of X-ray diffraction, Raman spectroscopy, thermogravimetric and differential thermal analyses, specific surface area measurements, scanning and transmission electron microscopies and chemical analysis. Fully tetragonal powders were obtained by both methods, as determined by X-ray diffraction and Raman spectroscopy. Both materials exhibited extremely small crystallite sizes (about 6 nm) and high specific surface areas (93 m{sup 2}/g and 42 m{sup 2}/g for gel-combustion and spray-pyrolysis powders, respectively). In both cases, no tetragonal-to-monoclinic transition was observed in the whole temperature range up to 1300 deg. C by differential thermal analysis. The amounts of the expected impurities (Si, B, C) were acceptable and comparable in both cases.

Lascalea, G.E. [Centro de Investigaciones en Solidos (CINSO), CITEFA-CONICET, J.B. de La Salle 4397, B1603ALO Villa Martelli, Pcia. de Buenos Aires (Argentina); Lamas, D.G. [Centro de Investigaciones en Solidos (CINSO), CITEFA-CONICET, J.B. de La Salle 4397, B1603ALO Villa Martelli, Pcia. de Buenos Aires (Argentina)]. E-mail: dlamas@citefa.gov.ar; Djurado, E. [Laboratoire dElectrochimie et de Physico-chimie des Materiaux et des Interfaces (LEPMI), INPG-CNRS. ENSEEG, 1130 Rue de la Piscine, BP 75, Domaine Universitaire, 38402 Saint Martin dHeres, Cedex (France); Cabanillas, E.D. [Centro Atomico Constituyentes, Comision Nacional de Energia Atomica, Gral. Paz 1499 (1650) San Martin, Pcia. de Buenos Aires (Argentina); Walsoee de Reca, N.E. [Centro de Investigaciones en Solidos (CINSO), CITEFA-CONICET, J.B. de La Salle 4397, B1603ALO Villa Martelli, Pcia. de Buenos Aires (Argentina)

2005-12-08

37

Photoluminescence of spray pyrolysis deposited ZnO nanorods  

PubMed Central

Photoluminescence of highly structured ZnO layers comprising well-shaped hexagonal rods is presented. The ZnO rods (length 500-1,000 nm, diameter 100-300 nm) were grown in air onto a preheated soda-lime glass (SGL) or ITO/SGL substrate by low-cost chemical spray pyrolysis method using zinc chloride precursor solutions and growth temperatures in the range of 450-550°C. We report the effect of the variation in deposition parameters (substrate type, growth temperature, spray rate, solvent type) on the photoluminescence properties of the spray-deposited ZnO nanorods. A dominant near band edge (NBE) emission is observed at 300 K and at 10 K. High-resolution photoluminescence measurements at 10 K reveal fine structure of the NBE band with the dominant peaks related to the bound exciton transitions. It is found that all studied technological parameters affect the excitonic photoluminescence in ZnO nanorods. PACS: 78.55.Et, 81.15.Rs, 61.46.Km

2011-01-01

38

Thin film lithium batteries prepared by spray pyrolysis  

Microsoft Academic Search

We have prepared thin film cathode materials and thin film electrolytes at temperatures ranging from 400C to 600C by a spray\\u000a pyrolysis technique. The sols used to prepare the films are made from simple inorganic salts and non toxic, inexpensive diols.\\u000a The sols can be sprayed in an air atmosphere to prepare films of the desired crystalline materials.

P. Fragnaud; D. M. Schleich

1995-01-01

39

Synthesis of lithium cobalt oxide using low-pressure spray pyrolysis  

NASA Astrophysics Data System (ADS)

A low pressure spray pyrolysis (LPSP) process was applied to synthesize crystalline lithium cobalt oxide as a battery cathode material via a liquid route. The effects of temperature and pressure of reactor on the synthesized particles characteristics were systematically investigated. Reactor temperatures of 800, 1000 and 1200 °C with pressures of 760 and 300 Torr were applied as operating conditions. The characterizations results show that the synthesized particles were highly crystalline and nearly spherical in shape. The results concluded that the low-pressure spray pyrolysis method has ability in control of particles morphology, crystallinity and atomic lithium-to-cobalt ratio.

Hidayat, Darmawan; Joni, I. Made; Setianto; Panatarani, Camellia; Okuyama, Kikuo

2013-09-01

40

Structural and optical properties of Cd 1- xSn xS semiconductor films produced by the ultrasonic spray pyrolysis method  

NASA Astrophysics Data System (ADS)

Cd 1- xSn xS semiconductor films have been produced onto glass substrates at 573 K substrate temperature by the ultrasonic spray pyrolysis (USP) method using an aqueous solution with varying tin concentrations. The thicknesses of the films have been calculated to be in the range of 1-4 ?m. The films have been characterized to evaluate the structure, morphology, composition and optical energy band gap. X-ray diffraction (XRD) studies show that the films are polycrystalline with hexagonal, tetragonal and orthorhombic structures. The morphological and compositional properties of the films have been investigated using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Sn concentrations in the films have been varied from 0% to 84% as determined from energy dispersive analysis. The optical band gap energies and types of optical transition of the films have been determined from the optical transmittance spectra. The optical band gap energy values of the films decrease from 2.43 to 1.21 eV as the Sn concentration increases.

Peker, Mehmet; Peker, Derya; Selami K?l?çkaya, M.

2010-12-01

41

Fabricate heterojunction diode by using the modified spray pyrolysis method to deposit nickel-lithium oxide on indium tin oxide substrate.  

PubMed

P-type lithium-doped nickel oxide (p-LNiO) thin films were deposited on an n-type indium tin oxide (ITO) glass substrate using the modified spray pyrolysis method (SPM), to fabricate a transparent p-n heterojunction diode. The structural, optical, and electrical properties of the p-LNiO and ITO thin films and the p-LNiO/n-ITO heterojunction diode were characterized by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), UV-visible spectroscopy, Hall effect measurement, and current-voltage (I-V) measurements. The nonlinear and rectifying I-V properties confirmed that a heterojunction diode characteristic was successfully formed in the p-LNiO/n-ITO (p-n) structure. The I-V characteristic was dominated by space-charge-limited current (SCLC), and the Anderson model demonstrated that band alignment existed in the p-LNiO/n-ITO heterojunction diode. PMID:23683053

Wu, Chia-Ching; Yang, Cheng-Fu

2013-06-12

42

Flame spray pyrolysis for sensing at the nanoscale  

NASA Astrophysics Data System (ADS)

Progress in developing novel gas sensors based on semiconducting metal oxides (SMOX) has been hindered by the cumbersome fabrication technologies currently employed. They involve time intensive synthesis procedures for gaining sensitive materials and preparation of the inks employed for realizing sensing layers. In this paper we review the opportunities offered by the relatively young method of flame spray pyrolysis, with which it is possible not only to synthesize a broad selection of SMOX in pure or doped form, but also to simultaneously deposit thick and highly porous gas sensitive films on a variety of substrates. In less than ten years the properties of nine base materials have been evaluated for all most relevant target gases and the obtained results are promising for future development.

Kemmler, J. A.; Pokhrel, S.; Mädler, L.; Weimar, U.; Barsan, N.

2013-11-01

43

Synthesis of Lithium-Cobalt Oxide Nanoparticles by Flame Spray Pyrolysis  

Microsoft Academic Search

Crystalline LiCoO2nanoparticles were synthesized from an aqueous solution of acetate compounds of lithium and cobalt by a flame spray pyrolysis, and characterized by TEM, XRD, and BET method. We investigated the evolution of LiCoO2nanoparticles from liquid droplets sprayed along the flame and observed disintegration of aqueous precursor droplets about 10?m into smaller fragments around 50 nm in the high temperature

Hee Jang; Chun Seong; Yong Suh; Heon Kim; Churl Lee

2004-01-01

44

Spray pyrolysis deposition of cadmium–zinc oxide thin films  

Microsoft Academic Search

Mixed thin film oxides of cadmium and zinc with different compositions were deposited on glass substrates by spray pyrolysis. The effect of the various parameters on the growth and on the film properties is presented. The sample structure was studied by X-ray diffraction (XRD) having found the presence of a cubic phase resembling that of pure CdO XRD pattern for

O. Vigil; L Vaillant; F Cruz; G Santana; A Morales-Acevedo; G Contreras-Puente

2000-01-01

45

Silver Nanoparticles from Ultrasonic Spray Pyrolysis of Aqueous Silver Nitrate  

Microsoft Academic Search

Silver particles less than 20 nm in diameter were synthesized by pyrolysis of an ultrasonically atomized spray of highly dilute aqueous silver nitrate solution at temperatures above 650°C and below the melting point of silver. Feed solution concentration and ultrasound power applied to the atomizer were found to have a significant impact on the particle size of the silver nanoparticles.

Kalyana C. Pingali; David A. Rockstraw; Shuguang Deng

2005-01-01

46

The thermal stability of porous alumina\\/stainless steel catalyst support obtained by spray pyrolysis  

Microsoft Academic Search

Active porous alumina coatings were obtained by deposition of boehmite sol on stainless steel (SS) substrate by spray pyrolysis method. The temperature and the doping of polyethylene glycol (PEG) and La3+ in the boehmite sol effects on the textural and structural properties and surface morphology of alumina coatings on stainless steel samples are presented.It was found that the addition of

Tatjana Novakovic; Nenad Radic; Boško Grbi?; Vera Dondur; Miodrag Mitric; Danijela Randjelovic; Dimitar Stoychev; Plamen Stefanov

2008-01-01

47

Microstructure control of SOFC cathodes using the self-organizing behavior of LSM\\/ScSZ composite powder material prepared by spray pyrolysis  

Microsoft Academic Search

Composite particles for SOFC cathodes were synthesized by a spray pyrolysis method. The constituent materials for the cathode are provided in the form of a metal ion solution with the addition of an electrolyte sol solution, and sprayed droplets of the solution undergo pyrolysis to form composite LSM\\/ScSZ particles. The resultant particles have been shown to possess a structure on

Akifusa Hagiwara; Natsuro Hobara; Koichi Takizawa; Kazuyoshi Sato; Hiroya Abe; Makio Naito

2007-01-01

48

Controlled synthesis of nanostructured particles by flame spray pyrolysis  

Microsoft Academic Search

The flame spray pyrolysis (FSP) process was systematically investigated using an external-mixing gas-assisted atomizer supported by six premixed methane–oxygen flameletes. The effect of oxidant and precursor fuel composition on the size of FSP-made silica primary particles (8–40nm) was studied using as precursor hexamethyldisiloxane (HMDSO) dissolved in ethanol, iso-octane or methanol. As oxidant air and pure oxygen were used, that served

L. Mädler; H. K. Kammler; R. Mueller; S. E. Pratsinis

2002-01-01

49

Homogeneous ZnO Nanoparticles by Flame Spray Pyrolysis  

Microsoft Academic Search

Zinc oxide (ZnO) nanoparticles were made by flame spray pyrolysis (FSP) of zinc acrylate–methanol–acetic acid solution. The effect of solution feed rate on particle specific surface area (SSA) and crystalline size was examined. The average primary particle diameter can be controlled from 10 to 20?nm by the solution feed rate. All powders were crystalline zincite. The primary particle diameter observed

Takao Tani; Lutz Mädler; Sotiris E. Pratsinis

2002-01-01

50

Preparation of ITO films using a spray pyrolysis solution containing an acetylacetone chelating agent  

NASA Astrophysics Data System (ADS)

Indium tin oxide (ITO) films were deposited on soda-lime glass substrates by the spray pyrolysis method using a spray solution of InCl3·3H2O as a precursor, SnCl4·5H2O as a dopant and acetylacetone (AcAcH) as a chelating agent. The effect of the addition of AcAcH to the spray solution on the surface morphology of the ITO film was investigated. The surface quality of the film prepared from the spray solution with AcAcH was better than that without AcAcH. The ITO film with the thickness of 230 nm, using the spray solution with AcAcH, exhibited the lowest resistivity of 4.75 × 10-4 ?·cm and higher optical transmittance of 85 %, respectively.

Gao, Yun; Zhao, Gaoyang; Duan, Zongfan; Ren, Yang

2014-01-01

51

Electrochemical properties of LiM 1\\/6Mn 11\\/6O 4 (M = Mn, Co, Al and Ni) as cathode materials for Li-ion batteries prepared by ultrasonic spray pyrolysis method  

Microsoft Academic Search

Spinel lithium manganese oxide LiMn2O4 and its substituted forms LiM1\\/6Mn11\\/6O4 (M=Co, Al and Ni) were prepared by ultrasonic spray pyrolysis method. As-prepared particles showed a spherical morphology and a densely congested interior structure. The geometric mean diameter was between 0.76 and 0.93?m, and the geometric standard deviation was approximately 1.33. The crystallite size was approximately 30nm, and the specific surface

I. Taniguchi; D. Song; M. Wakihara

2002-01-01

52

Laser-induced damage to spray pyrolysis deposited transparent conducting films  

Microsoft Academic Search

Laser-induced damage study of transparent conducting coatings of tin oxide prepared by spray pyrolysis has been made using a dye Q-switched Nd:glass laser emitting 25-ns (FWHM) pulses at 1062 nm. For comparison tin oxide films prepared by the chemical vapor deposition (CVD) method and indium tin oxide (ITO) prepared by the reactive RF sputtering method have also been damage tested.

P. Radhakrishnan; K. Sathianandan; N. Subhash

1986-01-01

53

Nanocrystalline MgZn Ferrite Obtained by Spray Pyrolysis  

NASA Astrophysics Data System (ADS)

Stoichiometric Mg0.5Zn0.5Fe2O4 powder was prepared by spray pyrolysis of water solution of inorganic metal salts in the presence of an inert component. Single phase ferrite with a cubic spinel-type structure and predominant grain size of 20-40 nm was observed after subsequent calcination of the powder at 700 °C and removal of the inert additive. Saturation magnetization of the powder was measured to be 32 emu/g at 300 K.

Kotsikau, D.; Pankov, V.; Petrova, E.

2013-05-01

54

LiFePO 4\\/carbon cathode materials prepared by ultrasonic spray pyrolysis  

Microsoft Academic Search

Small crystallites LiFePO4 powder with conducting carbon coating can be synthesized by ultrasonic spray pyrolysis. Cheaper trivalent iron ion is used as the precursor. The pure olivine phase can be prepared with the duplex process of spray pyrolysis (synthesized at 450, 550 or 650°C) and subsequent heat-treatment (at 650°C for 4h). The results indicate that the pyrolysis temperature of 450°C

Mu-Rong Yang; Tsung-Hsien Teng; She-Hung Wu

2006-01-01

55

Hg-based superconducting films prepared by spray pyrolysis technique  

SciTech Connect

Hg-Ba-Ca-Cu-O films have been prepared on silver substrates using a spray pyrolysis technique, following a two step procedure; first Ba-Ca-Cu-O films were prepared at a 350 C substrate temperature and annealed at 780 C for 6 hours to obtain a Ba-Ca-Cu-O precursor. Secondly, Hg-Ba-Ca-O films were prepared by spraying HgC{ell}{sub 2} on a Ba-Ca-Cu-O precursor at a 250 C substrate temperature. These films were then oxidized at 250 C for 10 hours in an oxygen atmosphere. Films thus obtained were characterized by studying their microphotography, X-ray diffraction pattern and electrical properties. These films show super conductivity below 87 K.

Pawar, S.H.; Pawaskar, P.N. [Shivaji Univ., Kolhapur (India). Energy Studies Lab.] [Shivaji Univ., Kolhapur (India). Energy Studies Lab.

1995-03-01

56

Properties of zinc telluride containing impurities introduced during spray pyrolysis  

SciTech Connect

Thin film ZnTe was prepared in two steps: (i) spray pyrolysis to form ZnO; followed by (ii) reaction between Te vapor and ZnO to form ZnTe. Large increases in thickness were observed when ZnO was converted to ZnTe. The films could be either p- or n-type depending on the Zn and Te content in the films. Dopants, which included B, Al, Ba, In, P, As, and Sb, were introduced during the spray pyrolysis state. The undoped ZnTe had a resistivity of the order of 10{sup 6} {Omega} cm. When Sb, B, and P were incorporated into the films, the p-ZnTe resistivity was decreased by three to six orders of magnitude. The lower resistivity value obtained for these films was 4.1 {Omega} cm for Sb, 9.7 {Omega} cm for P. Hole densities were as high as 10{sup 18} cm{sup {minus}3} when ZnTe was doped with Sb. Mobilities were generally around 1 cm{sup 2}/V s. The incorporation of Ga, Al, and As had inconsistent effects on the resistivity and on carrier type.

Merchant, J. De; Cocivera, M. [Univ. of Guelph, Ontario (Canada). Guelph-Waterloo Centre for Graduate Work in Chemistry

1996-12-01

57

Synthesis of Size-Controlled SrFe12O19 Using Modified Spray Pyrolysis-Calcination Method and Their Magnetic Properties  

NASA Astrophysics Data System (ADS)

Strontium hexaferrite (SrFe12O19, SrM) suitable for high-performance permanent magnet applications was synthesized by salt-assisted ultrasonic spray pyrolysis (SA-USP) and subsequent calcination. To control the particle size, the intermediate phase of SrM was collected by SA-USP and various sizes of SrM were obtained by calcining the as-prepared sample at temperatures ranging from 800°C to 1050°C. The synthesized SrM was magnetically aligned by using an external magnetic field to improve remanence. The synthesized particles were of nano- to submicron scale and nonagglomerated. The magnetic properties and squareness of the material depended on the particle size and distribution. Additionally, the NaCl added during synthesis facilitated the formation of nonagglomerated particles, while enhancing and controlling particle growth. The optimum magnetic properties were achieved at calcination temperature of 1000°C, resulting in coercivity of 5646 Oe, saturation magnetization of 73.3 emu/g, and remanence of 59.1 emu/g (80.6% of M s).

An, Guk-Hwan; Hwang, Tae-Yeon; Choa, Yong-Ho; Shin, Kyoosik

2014-06-01

58

Optical and electrical properties of aluminum oxide films deposited by spray pyrolysis  

Microsoft Academic Search

The optical and electrical characteristics of spray pyrolysis deposited aluminum oxide films are reported. The films were deposited from a spraying solution of aluminum acetylacetonate in N,N-dimethylformamide using an ultrasonic mist generator on (100) Si substrates. The addition of water mist during the spraying deposition process resulted in an overall improvement of the films characteristics. The substrate temperature during deposition

M. Aguilar-Frutis; M. Garcia; C. Falcony

1998-01-01

59

Spray pyrolysis deposited multiferroic BiFeO3 films  

NASA Astrophysics Data System (ADS)

BiFeO3 (BFO) films were prepared by nebulized spray pyrolysis technique on a single crystal LaAlO3 (001) substrate at ~300 °C and annealing in oxygen at ~550 °C for 1 h. In all films BFO is the majority phase having a rhombohedrally distorted structure with R3m symmetry and lattice parameters are a=3.96 A? and ?=89.7°. Atomic force microscopy reveals smooth and dense surface morphology. Despite the G-type antiferromagnetic spin structure of BFO the present BFO show well-defined M-H loops and unexpected ferromagnetism as evidenced by large saturation magnetization, ~125 emu/cc. The origin of anomalous ferromagnetism in the present films has been traced to the presence of nanometric Fe2O3 embedded in the BFO matrix.

Siwach, P. K.; Singh, Jai; Singh, H. K.; Varma, G. D.; Srivastava, O. N.

2009-04-01

60

In-situ fabrication of nanostructured cobalt oxide powders by spray pyrolysis technique.  

PubMed

Nano-crystalline Co3O4 and CoO powders have been prepared by a spray pyrolysis approach. The effects of the reaction temperature and initial salts on the crystallinity and phase composition have been studied. Based on the TEM and XRD results, the crystal sizes were in the range of 1-10 nm. SEM and TEM observations also reveal that the nano-powders easily create micron-scale spherical agglomerates. The Co3O4 powders obtained by spraying nitrate solution at 500 degrees C show high specific surface area, which according to the BET method is 82.37 m2/g. The time/temperature phase diagram of cobalt oxides developed from XRD and DTA/TGA analyses shows the existence of a CoO phase at low and high temperature ranges when some specific preparation conditions are applied. PMID:15570973

Zhao, Z W; Konstantinov, K; Yuan, L; Liu, H K; Dou, S X

2004-09-01

61

Methods and apparatuses for preparing upgraded pyrolysis oil  

DOEpatents

Methods and apparatuses for preparing upgraded pyrolysis oil are provided herein. In an embodiment, a method of preparing upgraded pyrolysis oil includes providing a biomass-derived pyrolysis oil stream having an original oxygen content. The biomass-derived pyrolysis oil stream is hydrodeoxygenated under catalysis in the presence of hydrogen to form a hydrodeoxygenated pyrolysis oil stream comprising a cyclic paraffin component. At least a portion of the hydrodeoxygenated pyrolysis oil stream is dehydrogenated under catalysis to form the upgraded pyrolysis oil.

Brandvold, Timothy A; Baird, Lance Awender; Frey, Stanley Joseph

2013-10-01

62

Relationship between the electrochemical and particle properties of LiMn 2O 4 prepared by ultrasonic spray pyrolysis  

Microsoft Academic Search

Spinel LiMn2O4 particles were successfully synthesized by an ultrasonic spray pyrolysis method from the precursor solutions; various combinations of nitrate, acetates or formats of lithium and manganese were stoichiometrically dissolved in distilled water. The product characteristics, such as crystallinity, specific surface area, particle morphology and interior structure of particles, were examined with X-ray diffraction (XRD), the Brunauer–Emmet–Teller (BET) method, field

K. Matsuda; I. Taniguchi

2004-01-01

63

Fabrication of CIGS thin films by using spray pyrolysis and post-selenization  

NASA Astrophysics Data System (ADS)

We fabricated Cu(In1- x Ga x )Se2 ( x: 0 ˜ 0.4) thin films by using ultrasonic spray pyrolysis and post-selenization. First, we made Cu(In1- x Ga x )S2 ( x: 0 ˜ 0.4) films by ultrasonic spray pyrolysis under an air environment. Then, we converted as-sprayed Cu(In1- x Ga x )S2 (CIGS) films to Cu-(In1- x Ga x )Se2 (CIGSe) films through post-selenization. For all Ga fractions, the sprayed CIGS films were well recrystallized into poly-crystalline CIGSe films with a dominant (112) texture, which was confirmed by X-ray diffraction, Raman spectroscopy and energy dispersive X-ray analyses. This result indicates that CIGSe films with any amount of Ga substitution can be made by converting sprayed CIGS to CIGSe with post-selenization.

Kim, Seong Yeon; Kim, JunHo

2012-06-01

64

Optimization of the synthesis conditions of LiCoO 2 for lithium secondary battery by ultrasonic spray pyrolysis process  

Microsoft Academic Search

LiCoO2 powders for lithium secondary battery were successfully prepared by the ultrasonic spray pyrolysis process. In this work, the statistical experimental design method was used to compare the characteristics (particle size, standard deviation, surface area, tab density) of the LiCoO2 particles according to the four parameters (synthesis temperature, sintering temperature, sintering time, sintering heating rate). The optimal synthesis conditions for

Kwan Young Choi; Ki Do Kim; Ji Won Yang

2006-01-01

65

Structural, optical, electrical properties and FTIR studies of fluorine doped SnO 2 films deposited by spray pyrolysis  

Microsoft Academic Search

Thin films of SnO2:F were prepared by ultrasonic spray pyrolysis method. The effect of fluorine concentration on the structural, optical, and\\u000a electrical properties of SnO2:F films was investigated. The X-ray diffraction results showed the preferred growth along (110). FTIR was employed to study\\u000a the defects in SnO2 lattice. The evidence of oxygen vacancy and substitution of fluorine for oxygen in

B. Zhang; Y. Tian; J. X. Zhang; W. Cai

2011-01-01

66

Uniform nanoparticles by flame-assisted spray pyrolysis (FASP) of low cost precursors  

Microsoft Academic Search

A new flame-assisted spray pyrolysis (FASP) reactor design is presented, which allows the use of inexpensive precursors and\\u000a solvents (e.g., ethanol) for synthesis of nanoparticles (10–20 nm) with uniform characteristics. In this reactor design, a\\u000a gas-assisted atomizer generates the precursor solution spray that is mixed and combusted with externally fed inexpensive fuel\\u000a gases (acetylene or methane) at a defined height above

Thomas Rudin; Karsten Wegner; Sotiris E. Pratsinis

2011-01-01

67

Influence of the process parameters on the spray pyrolysis technique, on the synthesis of gadolinium doped-ceria thin film  

SciTech Connect

Graphical abstract: Gas-tight CGO made by spray pyrolysis suitable to be used as SOFC electrolyte. Display Omitted Highlights: ? Dense and crystalline CGO films deposited by spray pyrolysis on various substrates. ? Solvent did not have a strong influence on the film microstructure, defect concentration or thickness. ? The substrate did not have a strong influence on the film microstructure, defect concentration or thickness. ? Films with at least 2.5 ?m of thickness presented high impermeability. ? The films obtained are suitable to use as a SOFC electrolyte. -- Abstract: This work presents the results of a process of optimization applied to gadolinia-doped ceria (Ce{sub 0.8}Gd{sub 0.2}O{sub 1.9?x}, or CGO) thin films, deposited by spray pyrolysis (SP). Spray pyrolysis is a high thermal deposition method that combines material deposition and heat treatment. This combination is advantageous since the post-deposition heat treatment step is not necessary. However, stresses are solidified in the coating during the deposition, which may lead to the initiation of a crack in the coating. The aim of this work was to achieve thin, dense, and continuous CGO coatings, which may be used as gas separation membranes and as a solid state electrochemical interfaces. Dense, flat, low-defect substrates such as silica slides, silicon mono crystal wafers, and porous substrates were used as substrates in this work. Cerium ammonium nitrate and gadolinium acetylacetonate were dissolved in ethanol and butyl carbitol to form a precursor solution that was sprayed on the heated substrates. Process parameters such as solvent composition, deposition rate and different heating regimes were analyzed. The microstructure was analyzed by secondary electron microscopy (SEM) and was found that thin, dense, and defect-free films could be produced on dense and porous substrates. The results obtained show that it is possible to obtain a CGO dense film deposited by spray pyrolysis. X-ray diffraction (XRD) analysis showed that the films were crystalline after the deposition without requiring post-deposition heat treatment. The crystallite size does not vary significantly as a function of the annealing temperature.

Halmenschlager, C.M., E-mail: cibelemh@yahoo.com.br [Laboratory of Materials Ceramic LACER/PPGEM, Federal University of Rio Grande do Sul, Av. Osvaldo Aranha, 99/705C, CEP: 90035-190, Porto Alegre, RS (Brazil); National Research Council, Institute for Fuel Cell Innovation NRC-IFCI, 4250 Wesbrook Mall, V6T 1W5 Vancouver, BC (Canada); Neagu, R. [National Research Council, Institute for Fuel Cell Innovation NRC-IFCI, 4250 Wesbrook Mall, V6T 1W5 Vancouver, BC (Canada)] [National Research Council, Institute for Fuel Cell Innovation NRC-IFCI, 4250 Wesbrook Mall, V6T 1W5 Vancouver, BC (Canada); Rose, L. [National Research Council, Institute for Fuel Cell Innovation NRC-IFCI, 4250 Wesbrook Mall, V6T 1W5 Vancouver, BC (Canada) [National Research Council, Institute for Fuel Cell Innovation NRC-IFCI, 4250 Wesbrook Mall, V6T 1W5 Vancouver, BC (Canada); Department of Materials Engineering, V6T 1Z1 Vancouver, BC (Canada); Malfatti, C.F. [Laboratory of Research in Corrosion LAPEC/PPGEM, Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 9500, Setor 4, Prédio 75/2° Andar, CEP: 91501-970, Campus do Vale, Porto Alegre, RS (Brazil)] [Laboratory of Research in Corrosion LAPEC/PPGEM, Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 9500, Setor 4, Prédio 75/2° Andar, CEP: 91501-970, Campus do Vale, Porto Alegre, RS (Brazil); Bergmann, C.P. [Laboratory of Materials Ceramic LACER/PPGEM, Federal University of Rio Grande do Sul, Av. Osvaldo Aranha, 99/705C, CEP: 90035-190, Porto Alegre, RS (Brazil)] [Laboratory of Materials Ceramic LACER/PPGEM, Federal University of Rio Grande do Sul, Av. Osvaldo Aranha, 99/705C, CEP: 90035-190, Porto Alegre, RS (Brazil)

2013-02-15

68

Spray pyrolysis of barrier layers for flexible thin film solar cells on steel  

Microsoft Academic Search

Thin film chalcopyrite solar cells grown on light-weight, flexible substrates are an appealing product. An insulating barrier layer is a requisite for flexible steel substrates to protect the chalcopyrite absorber layer from in-diffusion of iron and also to isolate the solar module, electrically, from the metal substrate. Spray pyrolysis is presented here as a means to deposit an aluminium oxide

Sophie Gledhill; Anton Zykov; Nicholas Allsop; Thorsten Rissom; Jan Schniebs; Christian A. Kaufmann; Martha Lux-Steiner; Christian-Herbert Fischer

2011-01-01

69

Thin Film CuInS2 Prepared by Spray Pyrolysis with Single-Source Precursors.  

National Technical Information Service (NTIS)

Both horizontal hot-wall and vertical cold-wall atmospheric chemical spray pyrolysis processes deposited near single-phase stoichiometric CuInS2 thin films. Single-source precursors developed for ternary chalcopyrite materials were used for this study, an...

M. H. Jin K. K. Banger J. D. Harris J. E. Cowen A. F. Hepp

2002-01-01

70

Preparation of Tb-Doped Y2SiO5 Phosphor by Spray Pyrolysis Using Two-Fluid Nozzle Spray Generator  

NASA Astrophysics Data System (ADS)

Tb-doped Y2SiO5 (YSO:Tb) phosphor particles having a mean particle size of more than 2 ?m and a narrow particle size distribution were prepared by spray pyrolysis using a two-fluid nozzle spray generator (marked SPs), and their crystallinity, photoluminescence (PL), and cathodeluminescence (CL) intensity were compared with those of YSO:Tb phosphor particles prepared using the sol-gel method (marked Sol-gel). It was found that non agglomerated precursor particles were formed by controlling the pyrolysis temperature and that the particle size distribution for SPs was much narrower than that for Sol-gel. In addition, the mean particle size of the SPs was changed by controlling the spray and carrier gas flow rates. An accurate X-ray diffraction Rietveld (XRD-Rietveld) analysis was successfully performed by using a cellulose resin; it was found that the crystallinity for SPs was as good as that for Sol-gel. The luminescence efficiency evaluated by the PL measurement for a certain condition of SPs (marked SP-2) was more or less the same as that for Sol-gel. On the other hand, the CL intensity for SP-2 was 15% higher than that for Sol-gel because of the former’s uniformly and densely packed CL measurement plate arranged using phosphor particles having a narrow particle size distribution.

Yokota, Hiroshi; Yoshida, Masato; Yagi, Yasuhiro; Ishibashi, Hiroyuki; Yano, Toyohiko; Yamamoto, Hajime

2008-01-01

71

Electrical Characteristics of High-Performance ZnO Field-Effect Transistors Prepared by Ultrasonic Spray Pyrolysis Technique  

NASA Astrophysics Data System (ADS)

We have fabricated ZnO-based thin-film transistors (TFTs) by low-cost ultrasonic spray pyrolysis. The devices exhibit high saturation mobility of about 0.6 cm2/Vs and on-off current ratio of 105. The electrical characteristics of ZnO-based TFTs show that ultrasonic spray pyrolysis technique can be used as a promising approach to attain high-performance electronic devices. Furthermore, the deposition techniques make the operating process attractive for flexible electronics.

Yi, Ming-Dong; Xie, Ling-Hai; Liu, Yu-Yu; Dai, Yan-Feng; Huang, Jin-Ying

2011-01-01

72

Effect of impurities on characteristics of ZrO 2 and ZnO ceramic powders produced by spray pyrolysis  

Microsoft Academic Search

Previously it was observed that addition of impurities to a precursor solution may alter the size and morphology of the particles\\u000a produced by spray pyrolysis. To investigate this further, the spray pyrolysis technique was used to prepare zirconia (ZrO2) and zinc oxide (ZnO) ceramic powders, with addition of slight amounts of NaCl in various concentrations. The results show\\u000a an increase

N. Jakic; J. Gregory; M. Eslamian; N. Ashgriz

2009-01-01

73

A comparative study of the photocatalytic activities of iron-titanium (IV) oxide photocatalysts prepared by various methods; spray pyrolysis, impregnation and co-precipitation  

Microsoft Academic Search

A series of iron\\/titanium oxide photocatalysts of varying Fe3+ content have beenprepared by a number of different methods and subjected to controlled thermal treatment. Specimens have been characterised in terms of their crystalline structure and morphology, and indicate solid solutions containing both the anatase and rutile phases of TiO2, together with the formation of pseudo-brookite in some specimens. Intrinsic photo-activity

Roger I. Bickley; Laurence T. Hogg; Teresita González-Carreño; Leonardo Palmisano

1995-01-01

74

Carbon Nanotubes Using Palm Oil as Carbon Source in Spray Pyrolysis System  

Microsoft Academic Search

Carbon nanotubes (CNTs) have been synthesized by catalytic decomposition of palm oil, on a silica powder support impregnated with Co, Ni and Co?Ni catalysts in the temperature range 500–900° C by the Spray Pyrolysis System. Co?Ni catalyst with 5 wt.% (molar ratio of Co:Ni = 1:1), impregnated in silica was found most suitable. Field Emission Scanning Electron Microscope (FESEM) reveals

A. A. Azira; N. F. A. Zainal; S. F. Nik; M. Rusop

2009-01-01

75

Carbon Nanotubes Using Palm Oil as Carbon Source in Spray Pyrolysis System  

Microsoft Academic Search

Carbon nanotubes (CNTs) have been synthesized by catalytic decomposition of palm oil, on a silica powder support impregnated with Co, Ni and Co\\/Ni catalysts in the temperature range 500-900° C by the Spray Pyrolysis System. Co\\/Ni catalyst with 5 wt.% (molar ratio of Co:Ni = 1:1), impregnated in silica was found most suitable. Field Emission Scanning Electron Microscope (FESEM) reveals

A. A. Azira; N. F. A. Zainal; S. F. Nik; M. Rusop

2009-01-01

76

Characterization of thorium dioxide thin films prepared by the spray pyrolysis technique  

Microsoft Academic Search

Thorium dioxide (ThO2) thin films were deposited by the spray pyrolysis technique onto a glass substrate maintained in the temperature range 100–350°C by using thorium nitrate as a starting solution. Structural, morphological, optical and electrical properties have been investigated. The results of FTIR showed that thorium nitrate is completely decomposed to ThO2 at 350°C, via two unstable intermediates. XRD patterns

Safwat A. Mahmoud

2002-01-01

77

Temperature optimisation of CNT synthesis by spray pyrolysis of alpha-pinene as the carbon source  

Microsoft Academic Search

Multi-wall carbon nanotubes (MWCNTs) were prepared by spray-pyrolysis of a botanical hydrocarbon, alpha-pinene and ferrocene as the catalyst at 700–1000°C. The MWCNTs were analysed by scanning electron microscopy, transmission electron microscopy, Raman spectroscopy and X-ray diffraction. The microscopy studies show the formation of carbon nanotubes with diameters between 20 and 30 nm and length greater than 100 µm. Raman spectroscopy

G. Alonso-Nuñez; J. Lara-Romero; M. Sanchez-Castañeda; S. Jiménez-Sandoval

2010-01-01

78

Titanium dioxide thin film deposited by spray pyrolysis of aqueous solution  

Microsoft Academic Search

Titanium dioxide thin film with a thickness of few microns was deposited on ITO\\/glass by spray pyrolysis of peroxo-tiatanium complex solution as precursor. The deposited TiO2 thin film was investigated for lithium ion intercalation\\/deintercalation behavior in organic solvent containing lithium ions and subsequently tested for anode material in thin film lithium ion battery. Thin film battery constructed with TiO2 film

C. Natarajan; N Fukunaga; G Nogami

1998-01-01

79

In situ fabrication of spherical porous tin oxide via a spray pyrolysis technique  

Microsoft Academic Search

Spherical porous tin oxide was fabricated via a spray pyrolysis technique. TEM revealed that the primary SnO2 crystals had an average size of 5–10nm. Good interconnection between SnO2 crystals is also observed. The electrochemical measurements showed that the spherical porous SnO2 samples have excellent cyclability, which can deliver a reversible capacity of 410mAh\\/g for up to 50 cycles as a

L. Yuan; Z. P. Guo; K. Konstantinov; J. Z. Wang; H. K. Liu

2006-01-01

80

Preparation and electrochemical characteristics of spherical spinel cathode powders via an ultrasonic spray pyrolysis process  

Microsoft Academic Search

Li1.03Co0.15Mn1.82O4 powders as cathode materials used in lithium-ion battery were synthesized using an ultrasonic spray pyrolysis process. The prepared powders were heated at 750°C for different heating durations. As the heating time increased, the crystallinity of the powders significantly enhanced. The nanometered primary particles were aggregated into sphere-like secondary particles with a porous structure. The surface area of the heated

Chung-Hsin Lu; Tai-Yuan Wu; Hung-Chun Wu; Mo-Hua Yang; Zheng-Zhao Guo; Izumi Taniguchi

2008-01-01

81

Porous carbon supports prepared by ultrasonic spray pyrolysis for direct methanol fuel cell electrodes  

Microsoft Academic Search

Carbon powders composed of porous micrometer-sized spheres were\\u000a synthesized from simple organic salt precursors using ultrasonic spray\\u000a pyrolysis (USP). These materials were tested as catalyst supports for a\\u000a direct methanol fuel cell (DMFC) catalyst and as pore formers in a\\u000a membrane electrode assembly (MEA). The effect of these materials on unit\\u000a cell performance was evaluated and compared to traditional Vulcan

Jin Ho Bang; Kookil Han; Sara E. Skrabalak; Hasuck Kim; Kenneth S. Suslick

2007-01-01

82

Violet-blue photoluminescence in aluminium oxide films prepared by ultrasonic spray pyrolysis  

Microsoft Academic Search

Violet-blue photoluminescent emission has been observed in aluminium oxide films deposited by the ultrasonic spray pyrolysis process at atmospheric pressure, using solutions of 0.05M aluminium acetylacetonate in a mixture of two parts of deionised water and two parts of methanol and aluminium chloride in the same solvent mixture. The films were deposited at substrate temperatures in the range from 240

A. Ortiz; J. C Alonso; V Pankov; D Albarran

1999-01-01

83

Synthesis of nano-sized biphasic calcium phosphate ceramics with spherical shape by flame spray pyrolysis  

Microsoft Academic Search

Nanometer size biphasic calcium phosphate (BCP) powders with various Ca\\/P molar ratios satisfied with appropriate phase ratios\\u000a of HA\\/?-TCP were prepared by high temperature flame spray pyrolysis process. The BCP powders had spherical shapes and narrow\\u000a size distributions irrespective of the ratios of Ca\\/P. The mean size of the BCP powders measured from the TEM image was 38 nm.\\u000a The composition

Jung Sang Cho; You Na Ko; Hye Young Koo; Yun Chan Kang

2010-01-01

84

Physical properties of zinc doped tin oxide films prepared by spray pyrolysis technique  

Microsoft Academic Search

The structural and optical properties of pure and zinc doped tin oxide (SnO2) thin films have been studied in detail. Thin films of pure and zinc doped tin oxide (Zn : SnO2) were prepared on Si(1 0 0) and quartz substrates by the spray pyrolysis technique at a substrate temperature of 400 °C. The zinc dopant concentration was varied from

S. Vijayalakshmi; S. Venkataraj; M. Subramanian; R. Jayavel

2008-01-01

85

Characterization of Tin disulphide thin films prepared at different substrate temperature using spray pyrolysis technique  

Microsoft Academic Search

Thin films of tin disulphide on glass substrates were prepared by spray pyrolysis technique using precursor solutions of SnCl2·2H2O and n–n dimethyl thiourea at different substrate temperatures varied in the range 348–423 K. Using the hot probe technique\\u000a the type of conductivity is found to be n type. X ray diffraction analysis revealed the polycrystalline nature with increasing\\u000a crystallinity with respect

K. Vijayakumar; C. Sanjeeviraja; M. Jayachandran; L. Amalraj

2011-01-01

86

Spray pyrolysis deposition and characterization of highly (100) oriented magnesium oxide thin films  

Microsoft Academic Search

Transparent dielectric thin films of MgO has been deposited on quartz substrates at different temperatures between 400 and 600°C by a pneumatic spray pyrolysis technique using Mg(CH3COO)2.4H2O as a single molecular precursor. The thermal behavior of the precursor magnesium acetate is described in the results of thermogravimetry analysis (TGA) and differential thermal analysis (DTA). The prepared films are reproducible, adherent

A. Moses; Ezhil Raj; L. C. Nehru; M. Jayachandran

2007-01-01

87

Investigation of Molybdenum Doped ZnO Thin Films Prepared by Spray Pyrolysis Technique  

Microsoft Academic Search

Molybdenum doped zinc oxide thin films were deposited on the Corning glass substrates pre-heated to 400°C by spray pyrolysis technique. The effect of molybdenum doping concentration (0–2 at.%) on the structural and optical properties of zinc oxide thin films was studied. X-ray diffraction analysis confirmed that the molybdenum doped ZnO films belong to the hexagonal crystal structure of ZnO. Atomic

V. Gokulakrishnan; S. Parthiban; K. Jeganathan; K. Ramamurthi

2011-01-01

88

Cubic or monoclinic Y 2O 3:Eu 3+ nanoparticles by one step flame spray pyrolysis  

Microsoft Academic Search

Continuous, single-step synthesis of monocrystalline Y2O3:Eu3+ nanophosphor particles (10–25nm in diameter and 5wt% Eu) was achieved by flame spray pyrolysis (FSP). The effect of FSP process parameters on materials properties was investigated by X-ray diffraction (XRD), nitrogen adsorption (BET) and transmission electron microscopy (TEM). Photoluminescence (PL) emission were measured as well as the time-resolved PL-intensity decay. Controlled synthesis of monoclinic

Adrian Camenzind; Reto Strobel; Sotiris E. Pratsinis

2005-01-01

89

The densification mechanism of hydroxyapatite particles during spray pyrolysis with variable carrier gas rates of flow.  

PubMed

The densification mechanism of hydroxyapatite particles during spray pyrolysis with varying carrier gas flow rates was investigated. A calcium phosphate solution with a Ca/P ratio of 1.67 was prepared by dissolving calcium nitrate tetrahydrate and diammonium hydrogen phosphate in deionized water followed by the addition of nitric acid. Hydroxyapatite particles were then synthesized by spray pyrolysis at 1500°C with carrier gas flow rates of 10, 30, and 50 L/min, respectively. The lower the carrier gas flow rate, the smaller and denser the as-prepared hydroxyapatite particles. Consequently, the lower flow rates produced particles with higher sinterability at 1100°C. The results can be explained in terms of the nucleation and growth mechanism based on the degree of supersaturation of hydroxyapatite in a droplet, which was dependent on the evaporating speed of nitric acid and water. The practical implication of these results is that highly sinterable hydroxyapatite powders can be synthesized via spray pyrolysis by reducing the carrier gas flow rate in a fixed temperature environment. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012. PMID:22121150

Cho, Jung Sang; Rhee, Sang-Hoon

2011-11-25

90

Development of a scalable spray pyrolysis process for the production of non-hollow battery materials  

NASA Astrophysics Data System (ADS)

Spray pyrolysis typically produces hollow particles when the particles are larger than about 2 microns. In this work, a scalable spray pyrolysis process was developed for the production of electrochemically active materials in a way that overcomes hollow sphere formation. With this new slurry spray pyrolysis process particles greater than 6 ?m have been successfully produced with a solid, yet porous interior morphology. Results indicate that the process shows great potential for the production of high quality, electrochemically active materials, as demonstrated by the electrochemical performance of layered Li1.2Mn0.54Ni0.13Co0.13O2 materials. The materials are phase pure, as observed by powder X-ray diffraction (XRD), and discharge capacities greater than 200 mAh g-1 after 100 cycles at C/3 rate (where 1 C = 200 mAh g-1) are consistently obtained. The standard deviation in discharge capacity for 5 batches of material produced under identical conditions was 11 mAh g-1. These promising electrochemical results were obtained at a scale of 50 g h-1 and with minimal process optimization, indicating the potential for commercial scale production.

Lengyel, Miklos; Elhassid, Dror; Atlas, Gal; Moller, William T.; Axelbaum, Richard L.

2014-11-01

91

Phase transition studies in bismuth ferrite thin films synthesized via spray pyrolysis technique  

NASA Astrophysics Data System (ADS)

Multiferroic are the materials, which combine two or more ``ferroic'' properties, ferromagnetism, ferroelectricity or ferroelasticity. BiFeO3 is the only single phase multiferroic material which possesses a high Curie temperature (TC ~ 1103 K), and a high Neel temperature (TN ~ 643 K) at room temperature. Normally sophisticated methods are being used to deposit thin films but here we have tried a different method Low cost Spray Pyrolysis Method to deposit BiFeO3 thin film of Glass Substrate with rhombohedral crystal structure and R3c space group. Bismuth Ferrite thin films are synthesized using Bismuth Nitrate and Iron Nitrate as precursor solutions. X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) were used to study structural analysis of prepared thin films. XRD pattern shows phase formation of BiFeO3 and SEM analysis shows formation of nanocrystals of 200 nm. High Temperature Resistivity measurements were done by using Keithley Electrometer (Two Probe system). Abrupt behavior in temperature range (313 K - 400K) has been observed in resistance studies which more likely suggests that in this transition the structure is tetragonal rather than rhombohedral. BiFeO3 is the potential active material in the next generation of ferroelectric memory devices.

Goyal, Ankit; Lakhotia, Harish

2013-06-01

92

Modelling and experimental investigations of thin films of Mg phosphorus-doped tungsten bronzes obtained by ultrasonic spray pyrolysis.  

PubMed

In this study, the synthesis of thin films of Mg phosphorus doped tungsten bronzes (MgPTB; MgHPW(12)O(40).29H(2)O) by the self-assembly of nano-structured particles of MgPTB obtained using the ultrasonic spray pyrolysis method was investigated. As the precursor, MgPTB, prepared by the ionic exchange method, was used. Nano-structured particles of MgPTB were obtained using the ultrasonic spray pyrolysis method. The nano-structure of the particles used as the building blocks in the MgPTB thin film were investigated experimentally and theoretically, applying the model given in this article. The obtained data for the mean particle size and their size distribution show a high degree of agreement. These previously tailored particles used for the preparation of thin films during the next synthesis step, by their self-assembly over slow deposition on a silica glass substrate, show how it is possible to create thin MgPTB films under advance projected conditions of the applied physical fields with a fully determined nanostructure of their building block particles, with a relatively small roughness and unique physical properties. PMID:19094050

Jokanovi?, V; Nedi?, Z; Colovi?, B

2008-12-01

93

Morphology Study of Prepared Carbon Nanotubes using Palm Oil as Carbon Source in Spray Pyrolysis Chemical Vapor Deposition  

Microsoft Academic Search

Surface morphology study on the influence of starting carbon materials by using newly developed spray pyrolysis chemical vapor deposition (Spray-CVD) to produced carbon nanotubes (CNTs) is investigated. The CNTs derived from palm oil as carbon sources were synthesized in Argon gas ambient by using Spray-CVD system. The major parameters are also evaluated in order to obtain high-yield and high-quality CNTs.

A. A. Azira; M. Rusop

2010-01-01

94

Characterization and Electrochromic Properties of Vanadium Oxide Thin Films Prepared via Spray Pyrolysis  

NASA Astrophysics Data System (ADS)

Vanadium oxide thin films were grown on glass substrates using spray pyrolysis technique. The effects of substrate temperature, vanadium concentration in the initial solution and the solution spray rate on the nanostructural and the electrochromic properties of deposited films are investigated. Characterization and the electrochromic measurements were carried out using X-ray diffraction, scanning electron microscopy and cyclic voltammogram. XRD patterns showed that the prepared films have polycrystalline structure and are mostly mixed phases of orthorhombic ?-V2O5 along with minor ?-V2O5 and V4O9 tetragonal structures. The preferred orientation of the deposited films was found to be along [101] plane. The cyclic voltammogram results obtained for different samples showed that only the films with 0.2 M solution concentration, 5 ml/min solution spray rate and 450°C substrate temperature exhibit two-step electrochromic properties. The results show a correlation between cycle voltammogram, morphology and resistance of the films.

Mousavi, M.; Kompany, A.; Shahtahmasebi, N.; Bagheri-Mohagheghi, M.-M.

2013-08-01

95

Preparation of AgInS{sub 2} chalcopyrite thin films by chemical spray pyrolysis  

SciTech Connect

AgInS{sub 2} thin films were prepared by the spray pyrolysis technique using a water/ethanol solution containing silver acetate, indium chloride and thiourea. We reported our results on the characterization of tetragonal AgInS{sub 2} (chalcopyrite type) films, which were grown from indium deficient spraying solution. The films displayed a n-type conductivity with room temperature resistivities in the range between 10{sup 3} and 10{sup 4} {omega} cm. The absorption spectra of sprayed films revealed two direct band-gaps with characteristic energies around 1.87 and 2.01 eV, which are in good agreement with the reported energy values for interband transitions from the split p-like valence band to the s-like conduction band in tetragonal AgInS{sub 2} single crystals.

Ortega-Lopez, M.; Vigil-Galan, O.; Cruz Gandarilla, F.; Solorza-Feria, O

2003-01-01

96

Electrical and optical properties of Al doped Zno film prepared by spray pyrolysis technique  

NASA Astrophysics Data System (ADS)

Transparent conducting thin films of zinc oxides and aluminum doped zinc oxide (AZO) were prepared by the spray pyrolysis technique using an aqueous solution of dehydrate zinc acetate (CH3COOH. 2H2O, pure- Merck A. R. grade) and hex hydrate aluminum chloride (AlCl3 .6H2O) on the micro glass slides. The prepared thin films are found to be highly adherent to the substrate and possess uniform conduction. The optical and electrical properties of the film were investigated in terms of different Al concentration in the starting solution and different substrate temperature. Four probe method in Van der pauw configuration was used for electrical resistivity measurements. The resistivity of Al doped film is observed to vary with doping concentration. The lowest resistivity is observed in the film doping with 2 at % [Al/Zn]. The Hall coefficient measurements show that both ZnO and AZO show the n-type conduction. The carrier concentration was observed to be highest at 2 at% of Al doping. The optical measurements of all the samples with aluminum concentrations was found to be >85 % showing the film to be highly transparent in nature. With increase in Al concentration, the optical band gap was observed increase from 3.27 eV to 3.41 eV.

Shrestha, Shankar Prasad; Basnet, Pradeep

2008-04-01

97

Yolk-shelled cathode materials with extremely high electrochemical performances prepared by spray pyrolysis.  

PubMed

A facile, continuous preparation process of yolk-shell-structured lithium-metal oxide powders without a template for use as cathode materials in lithium ion batteries is introduced for the first time. Single and double-shelled LiNi0.5Mn1.5O4 yolk-shell powders as the first target materials are prepared directly by spray pyrolysis from a spray solution with sucrose, at a short residence time of 4 s. Fast combustion and contraction of a carbon-mixed oxide composite intermediate, formed from a micro-sized droplet inside a hot wall reactor maintained at 700 °C, produces the yolk-shell powders. The yolk-shell structure of the precursor powders directly prepared by spray pyrolysis is well maintained even at a high post-treatment temperature of 750 °C. The yolk-shell LiNi0.5Mn1.5O4 powders delivered a 1000(th) high discharge capacity of 108 mA h g(-1) at 10 C. The discharge capacities are as high as 103, 95, and 91 mA h g(-1) at extremely high discharge rates of 100, 200, and 300 C and the corresponding specific energy densities are 420, 370, and 328 W h kg(-1). The capacity retention at a constant discharge rate of 200 C is 90% after 500 cycles. PMID:23846530

Choi, Seung Ho; Hong, Young Jun; Kang, Yun Chan

2013-09-01

98

Synthesis of nano-sized biphasic calcium phosphate ceramics with spherical shape by flame spray pyrolysis.  

PubMed

Nanometer size biphasic calcium phosphate (BCP) powders with various Ca/P molar ratios satisfied with appropriate phase ratios of HA/beta-TCP were prepared by high temperature flame spray pyrolysis process. The BCP powders had spherical shapes and narrow size distributions irrespective of the ratios of Ca/P. The mean size of the BCP powders measured from the TEM image was 38 nm. The composition ratio of Ca/P was controlled from 1.500 to 1.723 in the spray solution, and required phase ratios of HA/TCP are controlled systematically. The calcium dissolution of the pellets obtained from the BCP powders directly prepared by flame spray pyrolysis in buffer solution increased with the decrease of Ca/P ratios except with the Ca/P ratio of 1.713. The pellet surface with Ca/P ratio of 1.500, which consisted of beta-TCP, was eroded dramatically for 7 days. On the other hand, the pellet surface with Ca/P ratio of 1.667 was stable and did not disintegrate after immersion in Tris-HCl buffer solution based on the SEM observation. PMID:20052521

Cho, Jung Sang; Ko, You Na; Koo, Hye Young; Kang, Yun Chan

2010-04-01

99

Ultrasonic spray pyrolysis deposition of SnSe and SnSe2 using a single spray solution  

NASA Astrophysics Data System (ADS)

Thin films of SnSe and SnSe2 have been deposited using the ultrasonic spray pyrolysis (USP) technique. To the best of our knowledge this is the first report of the deposition of SnSe and SnSe2 thin films using a single spray solution. The use of a single spray solution for obtaining both a p-type material, SnSe, and an n-type material, SnSe2, simplifies the deposition technique. The SnSe2 thin films have a bandgap of 1.1 eV and the SnSe thin films have a band gap of 0.9 eV. The Hall measurements were used to determine the resistivity of the thin films. The SnSe2 thin films show a resistivity of 36.73 ?·cm and n-type conductivity while the SnSe thin films show a resistivity of 180 ?·cm and p-type conductivity.

Narro-Rios, Jorge Sergio; Ramachandran, Manoj; Martínez-Escobar, Dalia; Sánchez-Juárez, Aarón

2013-01-01

100

Preparation of dense, ultra-thin MIEC ceramic membranes by atmospheric spray-pyrolysis technique  

Microsoft Academic Search

Dense ceramic mixed ionic and electronic conducting membranes have been deposited by atmospheric spray-pyrolysis technique onto porous ceramic substrates. Perovskite oxide layers, i.e. manganites La1?xSrxMnO3, ferrites La1?xSrxFe1?y(Co,Ni)yO3, gallates La1?xSrxGa1?y(Co,Ni,Fe)yO3, cobaltites La1?xSrxCoO3 and related perovskites such as lanthanum nickelate La2NiO4 layers have been prepared. The structure, morphology and composition of the layers were characterised by XRD, SEM and WDS, respectively. Density

A Abrutis; A Teiserskis; G Garcia; V Kubilius; Z Saltyte; Z Salciunas; V Faucheux; A Figueras; S Rushworth

2004-01-01

101

Thin Film CuInS2 Prepared by Spray Pyrolysis with Single-Source Precursors  

NASA Technical Reports Server (NTRS)

Both horizontal hot-wall and vertical cold-wall atmospheric chemical spray pyrolysis processes deposited near single-phase stoichiometric CuInS2 thin films. Single-source precursors developed for ternary chalcopyrite materials were used for this study, and a new liquid phase single-source precursor was tested with a vertical cold-wall reactor. The depositions were carried out under an argon atmosphere, and the substrate temperature was kept at 400 C. Columnar grain structure was obtained with vapor deposition, and the granular structure was obtained with (liquid) droplet deposition. Conductive films were deposited with planar electrical resistivities ranging from 1 to 30 Omega x cm.

Jin, Michael H.; Banger, Kulinder K.; Harris, Jerry D.; Cowen, Jonathan E.; Hepp, Aloysius F.; Lyons, Valerie (Technical Monitor)

2002-01-01

102

Study of photoconductivity in Ni doped CdS thin films prepared by spray pyrolysis technique  

NASA Astrophysics Data System (ADS)

Ni-doped cadmium sulphide [Cd1-xNixS, (x=0, 0.03, 0.05 and 0.20)] thin films were investigated for photoconductive properties. The films were prepared by spray Pyrolysis technique (SPT). AFM and two probe resistivity measurements were carried out to analyze the morphological and electrical properties of the films. AFM shows the note worthy changes in the morphology where the nanorod structures in CdS is changed into nano particles with the Ni doping. The presence of persistence photo current is demonstrated and extensive photoconductivity analysis has been studied on these films.

Patidar, Manju Mishra; Ajay, Akhil; Wala, Arwa Dewas; N, Kiran; Panda, Richa; Gangrade, Mohan; Nath, R.; Ganesan, V.

2014-04-01

103

Synthesis of electrochromic tin oxide thin films with faster response by spray pyrolysis  

NASA Astrophysics Data System (ADS)

Tin oxide thin films have been synthesized via pyrolysis of tri- n-butyl tin acetate solution at various substrate temperatures. The effect of substrate temperature on electrochromic properties is studied by electrochemical cyclic voltammetry and chronoamperometry. The films deposited at various substrate temperatures (450, 475 and 500 °C) were polycrystalline and their preferred orientation changes from (1 1 0) to (2 0 0). Electrochromic performance indicated faster colour/bleach kinetics with appreciable reversibility in spray deposited SnO 2 films. Maximum colouration efficiency and reversibility was attained for the sample deposited at 500 °C. All the spray deposited SnO 2 thin films showed long term electrochemical stability in proton containing electrolyte.

Patil, P. S.; Sadale, S. B.; Mujawar, S. H.; Shinde, P. S.; Chigare, P. S.

2007-08-01

104

Nano-alpha-Al2O3 by liquid-feed flame spray pyrolysis.  

PubMed

Nanometre-sized particles of transition (t)-aluminas are important for the fabrication of high-quality alumina ceramics. Multiple tons are produced each year using a variety of gas-phase processes. The nanoparticles produced by these methods consist mainly of the undesired delta phase with some gamma- and theta-Al(2)O(3). Nano-t-aluminas should provide access to dense nano/submicrometre-grained alpha-Al(2)O(3) shapes offering significant advantages over micrometre-grained shapes. Unfortunately, polymorphism coupled with the high activation energy for nucleating alpha-Al(2)O(3) greatly impedes efforts to process dense alpha-Al(2)O(3) with controlled grain sizes, especially for submicrometre materials. Typically alpha-Al(2)O(3) nucleation within t-aluminas is sporadic rather than uniform, leading to exaggerated grain growth and vermicular microstructures without full densification (5). Thus, production of quantities of nano-alpha-Al(2)O(3) from multiple nano-t-aluminas for seeding or direct processing of alpha-Al(2)O(3) monoliths could greatly change how alpha-Al(2)O(3) components are processed. We report here that liquid-feed flame spray pyrolysis of nano-t-aluminas converts them to dispersible 30-80 nm alpha-Al(2)O(3) powders (50-85% phase transformed). Surprisingly, the powder surfaces are fully dehydrated. These powders pressureless sinter to more than 99.5% dense alpha-Al(2)O(3) with final grain sizes < or =500 nm without sintering aids. PMID:16892048

Laine, R M; Marchal, J C; Sun, H P; Pan, X Q

2006-09-01

105

Yolk-shelled cathode materials with extremely high electrochemical performances prepared by spray pyrolysis  

NASA Astrophysics Data System (ADS)

A facile, continuous preparation process of yolk-shell-structured lithium-metal oxide powders without a template for use as cathode materials in lithium ion batteries is introduced for the first time. Single and double-shelled LiNi0.5Mn1.5O4 yolk-shell powders as the first target materials are prepared directly by spray pyrolysis from a spray solution with sucrose, at a short residence time of 4 s. Fast combustion and contraction of a carbon-mixed oxide composite intermediate, formed from a micro-sized droplet inside a hot wall reactor maintained at 700 °C, produces the yolk-shell powders. The yolk-shell structure of the precursor powders directly prepared by spray pyrolysis is well maintained even at a high post-treatment temperature of 750 °C. The yolk-shell LiNi0.5Mn1.5O4 powders delivered a 1000th high discharge capacity of 108 mA h g-1 at 10 C. The discharge capacities are as high as 103, 95, and 91 mA h g-1 at extremely high discharge rates of 100, 200, and 300 C and the corresponding specific energy densities are 420, 370, and 328 W h kg-1. The capacity retention at a constant discharge rate of 200 C is 90% after 500 cycles.A facile, continuous preparation process of yolk-shell-structured lithium-metal oxide powders without a template for use as cathode materials in lithium ion batteries is introduced for the first time. Single and double-shelled LiNi0.5Mn1.5O4 yolk-shell powders as the first target materials are prepared directly by spray pyrolysis from a spray solution with sucrose, at a short residence time of 4 s. Fast combustion and contraction of a carbon-mixed oxide composite intermediate, formed from a micro-sized droplet inside a hot wall reactor maintained at 700 °C, produces the yolk-shell powders. The yolk-shell structure of the precursor powders directly prepared by spray pyrolysis is well maintained even at a high post-treatment temperature of 750 °C. The yolk-shell LiNi0.5Mn1.5O4 powders delivered a 1000th high discharge capacity of 108 mA h g-1 at 10 C. The discharge capacities are as high as 103, 95, and 91 mA h g-1 at extremely high discharge rates of 100, 200, and 300 C and the corresponding specific energy densities are 420, 370, and 328 W h kg-1. The capacity retention at a constant discharge rate of 200 C is 90% after 500 cycles. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr01675g

Choi, Seung Ho; Hong, Young Jun; Kang, Yun Chan

2013-08-01

106

Growth of ZnO and ZnMgO nanorods on Si substrates by using ultrasonic spray pyrolysis  

NASA Astrophysics Data System (ADS)

We demonstrate the growth of ZnO and ZnMgO nanorods on Si substrates through a two-step process without a catalyst by using a simple ultrasonic spray pyrolysis method. First, a ZnO thin film was deposited on a Si substrate to make a seed layer; then, ZnO and ZnMgO nanorods were deposited on that seed layer. ZnO and ZnMgO nanorods with a p-n junction were obtained by using nitrogen doping for p-type nanorods, and gallium doping for n-type nanorods. A distinct electroluminescence was observed at room temperature from the ZnO and the ZnMgO nanorod structures under forward bias conditions.

Nguyen, Hai Dong; Pandey, Rina; Yuldashev, Shavkat; Lee, Dong Jin; Kang, Tae Won

2012-05-01

107

Nanostructured ZnO films with various morphologies prepared by ultrasonic spray pyrolysis and its growing process  

NASA Astrophysics Data System (ADS)

Nanostructured ZnO films were prepared by the ultrasonic spray pyrolysis method using Zn(CH3COO)2·2H2O as a precursor. The effects of substrate temperature (Ts) on the morphology and properties were systematically studied. As the Ts increased from 430 °C to 610 °C, the morphology of the film transforms from closed packed nanosheets to dense nanocrystalline film and then to hexagonal nanorod array. The dense film formed at a temperature of 550 °C has the lowest electric resistivity and highest carrier concentration. The optical transmittance for all prepared samples was higher than 90%. The photoluminescence (PL) properties varied with the Ts due to the internal defect difference. The growth mechanism of ZnO film involves island growth and diffusion, which was evident by observing the samples prepared at various times.

Ma, H. L.; Liu, Z. W.; Zeng, D. C.; Zhong, M. L.; Yu, H. Y.; Mikmekova, E.

2013-10-01

108

Magnetic/luminescent core/shell particles synthesized by spray pyrolysis and their application in immunoassays with internal standard  

PubMed Central

Many types of fluorescent nanoparticles have been investigated as alternatives to conventional organic dyes in biochemistry; magnetic beads also have a long history of biological applications. In this work we apply flame spray pyrolysis in order to engineer a novel type of nanoparticle that has both luminescent and magnetic properties. The particles have magnetic cores of iron oxide doped with cobalt and neodymium and luminescent shells of europium-doped gadolinium oxide (Eu:Gd2O3). Measurements by vibrating sample magnetometry showed an overall paramagnetic response of these composite particles. Luminescence spectroscopy showed spectra typical of the Eu ion in a Gd2O3 host—a narrow emission peak centred near 615 nm. Our synthesis method offers a low-cost, high-rate synthesis route that enables a wide range of biological applications of magnetic/luminescent core/shell particles. Using these particles we demonstrate a novel immunoassay format with internal luminescent calibration for more precise measurements.

Dosev, Dosi; Nichkova, Mikaela; Dumas, Randy K; Gee, Shirley J; Hammock, Bruce D; Liu, Kai; Kennedy, Ian M

2008-01-01

109

Structural, optical and electrical properties of transparent conducting hydrophobic cadmium oxide thin films prepared by spray pyrolysis technique  

NASA Astrophysics Data System (ADS)

Cadmium oxide thin films were deposited by spray pyrolysis method on the glass substrate at 300 °C using different concentration of cadmium acetate. X-ray diffraction (XRD) measurements show that the coated CdO film belongs to cubic crystal structure with preferential orientation along (1 1 1) direction. Wettability results revealed that the hydrophobic character of CdO thin film is enhanced with increase in the precursor concentrations. The surface morphology and roughness of the films were determined by Atomic Force Microscope (AFM). The average optical transmittance of CdO films in the range 400–800 nm, is about 80%. The resistivity, mobility and carrier concentration of CdO thin films were determined by Hall effect measurement. Photoluminescence (PL) spectra showed a strong emission peak around 590 nm.

Sankarasubramanian, K.; Soundarrajan, P.; Sethuraman, K.; Ramesh Babu, R.; Ramamurthi, K.

2014-05-01

110

Dependence of of thickness F-doped SnO2 films grown by spray pyrolysis technique  

Microsoft Academic Search

Transparent conducting thin films of fluorine-doped SnO2 were deposited on glass substrates by spray pyrolysis technique in order to find out the effect of film thickness. These films were prepared using fluorine concentrations of 4 mol% at substrate temperature of 500°C. Their electrical resistivity decreased although optical transmittance decreased with increasing the film thickness.

Minoru Oshima; Yujin Takemoto; Kenji Yoshino

2009-01-01

111

Electrical and morphological properties of conducting layers formed from the silver–glass composite conducting powders prepared by spray pyrolysis  

Microsoft Academic Search

Ag–glass composite powders with various glass contents and excellent conducting properties were prepared by spray pyrolysis. Irrespective of the glass content, all the prepared powders were found to comprise spherical particles with nonaggregation characteristics. The crystal structure of the powder particles resembled that of pure Ag particles, irrespective of the glass content. Conducting layers formed from pure Ag did not

D. S. Jung; H. Y. Koo; Y. C. Kang

2010-01-01

112

Synthesis and characterization of nickel oxide thin films deposited on glass substrates using spray pyrolysis  

NASA Astrophysics Data System (ADS)

A simple and inexpensive spray pyrolysis technique was employed to deposit nickel oxide (NiO) thin films from hydrated nickel chloride salt solution onto amorphous glass substrate. The as-deposited films were transparent, uniform and well adherent to the glass substrate. The effect of the substrate temperature, the volume and the concentration of the sprayed solution on the structural, optical and electrical properties was studied using X-ray diffraction, optical transmittance, four point probe, scanning electron microscopy and atomic force microscopy. The structural analyses show that all the samples have a cubic structure. It was found that the increase in the volume of sprayed solution leads to an increment in the crystallite size of NiO and improves the homogeneity of the film. Optical measurements have shown that an increase in the thickness of the layer results in a decrease in the optical transmission, but it remains higher than 70% even if the thickness exceeds 600 nm. At the same time, the optical gap decreases from 3.7 to 3.55 eV when the thickness increases from 133 to 620 nm. Low values of the electrical resistivity (less than 10 ? cm) were obtained for thin films with thicknesses less than about 240 nm, but for higher thicknesses the resistivity increases linearly to reach about 170 ? cm for a thickness of 620 nm.

Jlassi, M.; Sta, I.; Hajji, M.; Ezzaouia, H.

2014-07-01

113

Formation of CuAlO2 Film by Ultrasonic Spray Pyrolysis  

NASA Astrophysics Data System (ADS)

Smooth, crack free and homogenous CuAlO2 film was produced by chemical solution deposition process via spray pyrolysis technique on a cleaned Si substrate. The precursor solution used was comprised of a mixture of 45.87 mmol Cu(NO3)2.3H2O and 90 mmol Al(NO3)3.9H2O at ratio of Cu:Al = 1.2:1. The precursor solution was placed in a mist chamber and was atomized by a nebulizer to produce precursor mist. The precursor mist was then carried out by Ar gas and was sprayed onto a heated Si. Two main parameters were studied: the distance between the nozzle of the precursor mist chamber and the Si and the temperature of the Si substrate. It appears that from the XRD data, CuAlO2 can be detected for samples prepared by spraying the precursor mist at temperature of > 550 °C with distance between the nozzle and the substrate of 3cm. Reaction of the Cu and Al ions in the mist near the substrate may have promoted the crystallisation of CuAlO2.

Iping, S.; Lockman, Zainovia; Hutagalung, S. D.; Kamsul, A.; Matsuda, Atsunori

2011-10-01

114

Waste plastic pyrolysis process control method based on morphological characteristics  

Microsoft Academic Search

During pyrolysis process reaction state of waste plastics cannot be easily observed and controlled, which makes it is difficult to control the process precisely. In this paper, a new process control method is proposed based on some special morphological characteristics of plastic wastes during their pyrolysis process. These characteristics' quantitative values can be obtained by sampling photograph images in sequence

Wang Hai; Chen De-zhen; Wang Zhong-hui; Zhou Gongming

2011-01-01

115

Preparation of indium sulfide thin films by spray pyrolysis using a new precursor indium nitrate  

NASA Astrophysics Data System (ADS)

Indium nitrate and thiourea were used as the precursor solutions for preparing indium sulfide thin films using Chemical Spray Pyrolysis (CSP) technique. Films having various In/S ratios were characterized using X-Ray Diffraction (XRD), Energy Dispersive X-ray Analysis (EDX), Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), optical absorption, transmission and photosensitivity measurements. Sample having In/S ratio 2/3 showed better crystallinity with band gap 2.66 eV. Depth profile of the sample also indicated the formation of indium sulfide. It was also observed that In/S ratio in the initial precursor solution determined the composition as well as electrical properties of the films. Maximum photosensitivity was observed for the sample prepared using solution having In/S ratio 2/4.

John, Teny Theresa; Kartha, C. Sudha; Vijayakumar, K. P.; Abe, T.; Kashiwaba, Y.

2005-12-01

116

Synthesis and Characterization of MgB2 Films Deposited by Ultrasonic Spray Pyrolysis  

NASA Astrophysics Data System (ADS)

The MgB2 films have been prepared on the c-cut sapphire substrates by ultrasonic spray pyrolysis (USP) technique using Boric acid and Magnesium acetate tetrahydrate dissolved into distillated water and ethanol as starting materials. The overall concentrations were fixed at 0.1mol/L. During the deposition, 96% Ar - 4% H2 was used as carrier gas. The reaction temperatures were 850 °C, 900 °C and 950 °C . The deposited MgB2 films showed strongly (1 0 1) plane orientation. In the sample deposited at 950 °C for 5min, MgB2 film showed a homogeneous surface, with good grain connectivity. The critical temperature (Tc) was observed to be 31.5 K. The crystal structural and microstructural properties of the MgB2 films prepared by USP were observed to be strongly dependent on the reacting temperature.

Chung, Jun-Ki; Kim, Won-Jeong; Lim, Yeong-Jin; Park, Sung-Chang; Kim, Cheol-Jin

117

Magnetism of Co-doped titania thin films prepared by spray pyrolysis  

NASA Astrophysics Data System (ADS)

Co-doped TiO2 (anatase) films prepared by spray pyrolysis at 500 °C are investigated for the possible existence of room temperature ferromagnetism (RTF). These films were characterized by x-ray diffraction, Raman spectroscopy, and x-ray photoelectron spectroscopy at room temperature, followed by studies of the temperature and magnetic field dependence of the magnetization by squid magnetometry. For Co doping of upto 10 at. %, no phase other than anatase could be detected, and there is no RTF in these films. Instead, the magnetic susceptibility ? fits the modified Curie-Weiss law ?=?0+C/(T+?), with ?~=5 K and magnitude of C consistent with Co2+ paramagnetism in Ti1-xCoxO2-x. Only for T<=5 K, a hysteresis loop with coercivity Hc=200 Oe is observed. These observations suggest Co2+ paramagnetism, with exchange interaction becoming important for T<=5 K in the case of 10% Co/TiO2 films.

Manivannan, A.; Seehra, M. S.; Majumder, S. B.; Katiyar, R. S.

2003-07-01

118

Hydrogen sensitivity performance of Pd doped SnO2 nanostructured film fabricated by spray pyrolysis.  

PubMed

The present investigation dealt with the fabrication of H2 gas sensor based on Pd doped SnO2. Porous SnO2 nanostructured film were fabricated by spray pyrolysis route using tin chloride pentahydrate (SnCl4.5H2O) solution as starting material, and PdCl2 as a dopant. Resistance measurements at different temperatures and concentration of H2 have been carried out with the samples. Microstructure and palladium dopant have been found to be critical factors determining the gas sensing properties of Pd/SnO2 specimens. The comparative gas sensitivity tests showed the excellent H2 sensing properties of the sensor in air was suggested to arise mainly from the improvement of gas absorption and catalytic effect of nano Pd dopant. PMID:19441376

Wu, Xiaomeng; Ling, Yunhan; Zhi, Xin; Huang, Zhaohui

2009-02-01

119

Dark field optical imaging and photoluminescence spectra from ZnO microstructures obtained by spray pyrolysis  

NASA Astrophysics Data System (ADS)

In this work we present results on ZnO self-assembled microstructures obtained by modified ultrasonic spray pyrolysis technique. We show optical imaging and photoluminescence spectrum from a typical self-assembled ZnO microstructure grown on Si(100) substrate. The dendritic formation of ZnO clusters achieved with our technique allows us to study both structural defects and heat routes in ZnO films. After thermal treatment, enhanced green and red emissions were observed on PL spectrum of the ZnO microstructures. The energy band gap from a typical structure was 3.13 eV, lower than usual for thick ZnO film, and a clear dependence with substrate surface roughness was also observed.

Silva, T. G.; Ribeiro, E.; Silveira, E.

120

Optoelectronic characteristics of YAG phosphor-incorporated ZnO films deposited by ultrasonic spray pyrolysis  

NASA Astrophysics Data System (ADS)

This work presents a novel white light device. An yttrium aluminum garnet (YAG) phosphor-incorporated zinc oxide (ZnO) film is deposited on a slide glass substrate by ultrasonic spray pyrolysis. A nanoflower consisting of a hexagonal nanopetal is formed on the surfaces of the samples, and the sizes of the nanopetal are approximately 200 to 700 nm. Additionally, the nanopetal becomes blunted with an increasing incorporated amount of YAG. As the incorporated amount is 1.5 and 2.5 wt.%, the photoluminescence color of the YAG-incorporated ZnO film is nearly white, possibly contributing to the YAG emission and the band-to-deep level transition in the ZnO film.

Chen, Lung-Chien; Huang, Chien-Chung

2012-11-01

121

Optoelectronic characteristics of YAG phosphor-incorporated ZnO films deposited by ultrasonic spray pyrolysis.  

PubMed

This work presents a novel white light device. An yttrium aluminum garnet (YAG) phosphor-incorporated zinc oxide (ZnO) film is deposited on a slide glass substrate by ultrasonic spray pyrolysis. A nanoflower consisting of a hexagonal nanopetal is formed on the surfaces of the samples, and the sizes of the nanopetal are approximately 200 to 700 nm. Additionally, the nanopetal becomes blunted with an increasing incorporated amount of YAG. As the incorporated amount is 1.5 and 2.5 wt.%, the photoluminescence color of the YAG-incorporated ZnO film is nearly white, possibly contributing to the YAG emission and the band-to-deep level transition in the ZnO film. PMID:23151219

Chen, Lung-Chien; Huang, Chien-Chung

2012-01-01

122

Thulium and Ytterbium-Doped Titanium Oxide Thin Films Deposited by Ultrasonic Spray Pyrolysis  

NASA Astrophysics Data System (ADS)

Thin films of thulium and ytterbium-doped titanium oxide were grown by metal-organic spray pyrolysis deposition from titanium(IV)oxide bis(acetylacetonate), thulium(III) tris(2,2,6,6-tetramethyl-3,5-heptanedionate) and ytterbium(III) tris(acetylacetonate). Deposition temperatures have been investigated from 300 to 600 °C. Films have been studied regarding their crystallinity and doping quality. Structural and composition characterisations of TiO2:Tm,Yb were performed by electron microprobe, x-ray diffraction, and Fourier transform infrared spectroscopy. The deposition rate can reach 0.8 ?m/h. The anatase phase of TiO2 was obtained after synthesis at 400 °C or higher. Organic contamination at low deposition temperature is eliminated by annealing treatments.

Forissier, Sébastien; Roussel, Hervé; Chaudouet, Patrick; Pereira, Antonio; Deschanvres, Jean-Luc; Moine, Bernard

2012-12-01

123

Improvement on droplet production rate of ultrasonic - nebulizer in spray pyrolysis process  

NASA Astrophysics Data System (ADS)

Atomization is an important part in Spray Pyrolysis (SP) process which is applied to synthesize submicron or nano sized particles or to deposit thin film. Ultrasonic Nebulizer (UN) is usually use in SP due to its homogeneous droplets production with size between 1-5 ?m. The drawback of the UN is low droplets production rate. In this research, we successfully developed a Digital Ultrasonic Nebulizer (DUN) with high droplets production rate using two ultrasonic traducers with applied frequency of 2.4 MHz. The result of DUN atomization was improved 4-6 fold compare to the conventional UN. The DUN also has an additional digital features such as pushbutton, LCD and microcontroller which is allow to set duration and applied voltage.

Panatarani, Camellia; Demen, Tuti Aryati; Men, Liu Kin; Maulana, Dwindra Wilham; Hidayat, Darmawan; Joni, I. Made

2013-09-01

124

Emission and Structure Varieties in ZnO:Ag Nanorods Obtained by Ultrasonic Spray Pyrolysis  

NASA Astrophysics Data System (ADS)

Scanning electronic microscopy (SEM), X ray diffraction (XRD) and photoluminescence (PL) have been applied to the study of the structural and optical properties of ZnO nanocrystals prepared by the ultrasonic spray pyrolysis (USP) at different temperatures. The variation of temperatures and times at the growth of ZnO films permits modifying the ZnO phase from the amorphous to crystalline, to change the size of ZnO nanocrystals (NCs), as well as to vary their photoluminescence spectra. The study has revealed three types of PL bands in ZnO NCs: defect related emission, the near-band-edge (NBE) PL, related to the LO phonon replica of free exciton (FE) recombination, and FE second-order diffraction peaks. The PL bands related to the LO phonon replica of FE in PL spectra measured at room temperature testify on the high quality of ZnO films prepared by the USP technology.

Velázquez Lozada, E.; Torchynska, T. V.; Casas Espinola, J. L.

2014-04-01

125

Enhanced early osteogenic differentiation by silicon-substituted hydroxyapatite ceramics fabricated via ultrasonic spray pyrolysis route.  

PubMed

The influence of silicon-substituted hydroxyapatite (Si-HAp) on osteogenic differentiation was assessed by biological analysis. Si-HAp was prepared by ultrasonic spray pyrolysis (USSP) technique using various amounts of Si (0, 0.8, and 1.6 mass%). Chemical analysis revealed that Si was incorporated into the hydroxyapatite (HAp) lattice with no other crystalline phase and which caused the change of crystal structure. Biological analyses showed that the Si contents affected the cell proliferation and morphology, suggesting that there is an optimal Si content for cell culture. As for differentiation, alkaline phosphatase activity and osteocalcin production of Si-HAp were higher than those of HAp. Gene expression profiles also revealed that substitution of Si (0.8 mass%) up-regulated the expression levels of osteocalcin and especially Runx2, a master gene for osteoblast development. These results suggest that incorporating Si into the HAp lattice may enhance the bioactivity, particularly during early osteoblast development. PMID:22890519

Honda, Michiyo; Kikushima, Koichi; Kawanobe, Yusuke; Konishi, Toshiisa; Mizumoto, Minori; Aizawa, Mamoru

2012-12-01

126

Anomalous ferromagnetism in spray pyrolysis deposited multiferroic BiFeO3 films  

NASA Astrophysics Data System (ADS)

Oriented polycrystalline BiFeO3 (BFO) films are deposited on single crystal LaAlO3 (001) substrates by nebulized spray pyrolysis technique at low temperature of ~300 °C. Annealing of the as deposited films in air and oxygen at ~550 °C for 1 h is found to produce crystallization and BFO phase formation. X-ray diffraction results show rhombohedral disordered perovskite structure with space group R3m. As revealed by atomic force microscopy, grain size increases with oxygen annealing. Magnetic measurements show well-defined hysteretic loops at room temperature for both the films. However, oxygenation leads to dramatic increase in room temperature ferromagnetism as evidenced by large saturation magnetization of ~250 emu/cm3. This enhanced magnetization is attributed to the presence of iron oxide rich nanoclusters due to oxygen annealing.

Siwach, P. K.; Singh, H. K.; Singh, Jai; Srivastava, O. N.

2007-09-01

127

Cubic or monoclinic Y 2O 3:Eu 3+ nanoparticles by one step flame spray pyrolysis  

NASA Astrophysics Data System (ADS)

Continuous, single-step synthesis of monocrystalline Y 2O 3:Eu 3+ nanophosphor particles (10-25 nm in diameter and 5 wt% Eu) was achieved by flame spray pyrolysis (FSP). The effect of FSP process parameters on materials properties was investigated by X-ray diffraction (XRD), nitrogen adsorption (BET) and transmission electron microscopy (TEM). Photoluminescence (PL) emission were measured as well as the time-resolved PL-intensity decay. Controlled synthesis of monoclinic or cubic Y 2O 3:Eu 3+ nanoparticles was achieved without post-treatment by controlling the high temperature residence time of these particles. The cubic nanoparticles exhibited longer decay times but lower maximum PL intensity than commercial micron-sized bulk Y 2O 3:Eu 3+ phosphor powder.

Camenzind, Adrian; Strobel, Reto; Pratsinis, Sotiris E.

2005-11-01

128

Structural and morphological characterization of TiO2 thin films synthesized by spray pyrolysis technique.  

PubMed

Thin films of nanocrystalline TiO2 were synthesized by spray pyrolysis technique in the temperature range 300 degrees C to 550 degrees C in steps of 50 degrees C. The films were coated on glass and quartz substrates by ultrasonic nebulization of titanium-oxy-acetyl acetonate followed by pyrolysis. The structure and morphology of the thin films were characterized by X-ray Diffraction (XRD), Raman Spectroscopy (RS) and Scanning Electron Microscopy (SEM), while the optical band gaps were measured by Spectroscopic Ellipsometry (SE) and UV-Visible spectroscopy. XRD investigations revealed distinct crystal structures of the films synthesized above and below 300 degrees C. While films grown at substrate temperature 300 degrees C were amorphous, those grown at 350 dgrees C and above showed tetragonal anatase crystal structure. The morphological investigations from SEM showed that the films deposited at 350 degrees C were porous and exhibited flower like morphology. The microstructures of the films grown on quartz at 450 degrees C were found to be uniform and dense. The nominal grain sizes evaluated from High Resolution SEM (HRSEM) studies were approximately 20 nm and compared well with the grain sizes calculated from XRD. The band gap values calculated from ellipsometry studies were approximately 3.7 eV and 3.95 eV for the films grown at 450 degrees C and 350 degrees C, respectively. This is in good agreement with those obtained from UV-Visible spectroscopy. PMID:19928217

Raut, N C; Mathews, Tom; Sundari, S Tripura; Sairam, T N; Dash, S; Tyagi, A K

2009-09-01

129

Flame temperature trends in reacting vanadium and tungsten ethoxide fluid sprays during CO2-laser pyrolysis  

NASA Astrophysics Data System (ADS)

We observe the "invisible-to-the-naked-eye" flames of tungsten and vanadium ethoxide aerosols when ignited at moderate laser excitation (0< P laser<70 W) by employing an IR thermo-graphic camera. No emission is seen in the visible range whether by the visible region cameras or by spectroscopy. The emissivity of the precursor solution measured was 0.80 and 0.75 for tungsten and vanadium ethoxide, respectively. The spectral emissivities of the tungsten and vanadium ethoxide flames measured using FTIR-spectrometer were used to calculate the pyrolysis flame temperature at various laser intensities and wavelengths. New energy balance equations have been derived—the transient temperature one extended from Haggerty-Cannon equation and the other based on standard resonance analysis. Fitting these models to experimental data reveals that only small amounts (1.33% and 4.32%, respectively) of the laser power are used in the pyrolysis of the precursor ethoxide aerosols into the desired oxide nanostructures. The low levels of specific heat capacity values obtained in these sprays suggest that these are electronic heat capacities rather than lattice heat capacities; enthalpies are also obtained. The experimental temperature-laser power trends observed were in agreement with previous findings from Tenegal et al. (Chem. Phys. Lett. 335:155, 2001). The damping coefficients, and hence the saturation intensities confirm that the vanadium containing precursor liquid is harder to dissociate into final products than the tungsten precursor as observed experimentally.

Mwakikunga, B. W.; Mudau, A. E.; Brink, N.; Willers, C. J.

2011-11-01

130

Characterization of WO3/ZnO Nanocomposites Synthesized by Flame Spray Pyrolysis  

NASA Astrophysics Data System (ADS)

Flame spray pyrolysis (FSP) was employed to synthesize pure ZnO and WO3/ZnO nanocomposites containing 0.25, 0.50, 0.75 and 1.0 mol% WO3. WO3 is one of the most versatile and widely applied catalytic metal oxides. Precursor solutions of zinc naphthenate and tungsten ethoxide in ethanol were sprayed and combusted, resulting in crystalline and nanostructured particles. The crystalline phase, morphology and size of the nanoparticles were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The specific surface area of the nanocomposites was measured by nitrogen adsorption (BET analysis). The ZnO nanocomposites were observed as particles having clear spheroidal, hexagonal and rod-like morphologies. The crystallite sizes of spheroidal and hexagonal ZnO particles were in the range of 5-20 nm. ZnO nanorods were found to be range from 5-10 nm in width and 10-25 nm in length. The WO3 compositions of the ZnO samples were verified by energy dispersive x-ray spectroscopy (EDS).

Siriwong, C.; Wetchakun, N.; Liewhiran, C.; Phanichphant, S.

2009-07-01

131

Low temperature synthesis of wurtzite zinc sulfide (ZnS) thin films by chemical spray pyrolysis.  

PubMed

Zinc sulfide (ZnS) thin films have been synthesized by spray pyrolysis at 310 °C using an aqueous solution of zinc chloride (ZnCl2) and thioacetamide (TAA). Highly crystalline films were obtained by applying TAA instead of thiourea (TU) as the sulfur source. X-ray diffraction (XRD) analyses show that the films prepared by TAA contained a wurtzite structure, which is usually a high temperature phase of ZnS. The crystallinity and morphology of the ZnS films appeared to have a strong dependence on the spray rate as well. The asymmetric polar structure of the TAA molecule is proposed to be the intrinsic reason of the formation of highly crystalline ZnS at comparatively low temperatures. The violet and green emissions from photoluminescence (PL) spectroscopy reflected the sulfur and zinc vacancies in the film. Accordingly, the photodetectors fabricated using these films exhibit excellent response to green and red photons of 525 nm and 650 nm respectively, though the band gaps of the materials, estimated from optical absorption spectroscopy, are in the range of 3.5-3.6 eV. PMID:23546181

Zeng, Xin; Pramana, Stevin S; Batabyal, Sudip K; Mhaisalkar, Subodh G; Chen, Xiaodong; Jinesh, K B

2013-05-14

132

Flame spray pyrolysis: An enabling technology for nanoparticles design and fabrication.  

PubMed

Combustion of appropriate precursor sprays in a flame spray pyrolysis (FSP) process is a highly promising and versatile technique for the rapid and scalable synthesis of nanostuctural materials with engineered functionalities. The technique was initially derived from the fundamentals of the well-established vapour-fed flame aerosols reactors that was widely practised for the manufacturing of simple commodity powders such as pigmentary titania, fumed silica, alumina, and even optical fibers. In the last 10 years however, FSP knowledge and technology was developed substantially and a wide range of new and complex products have been synthesised, attracting major industries in a diverse field of applications. Key innovations in FSP reactor engineering and precursor chemistry have enabled flexible designs of nanostructured loosely-agglomerated powders and particulate films of pure or mixed oxides and even pure metals and alloys. Unique material morphologies such as core-shell structures and nanorods are possible using this essentially one step and continuous FSP process. Finally, research challenges are discussed and an outlook on the next generation of engineered combustion-made materials is given. PMID:20820719

Teoh, Wey Yang; Amal, Rose; Mädler, Lutz

2010-08-01

133

Cathode performance of LiMnPO 4\\/C nanocomposites prepared by a combination of spray pyrolysis and wet ball-milling followed by heat treatment  

Microsoft Academic Search

LiMnPO4\\/C nanocomposites could be prepared by a combination of spray pyrolysis and wet ball-milling followed by heat treatment in the range of spray pyrolysis temperature from 200 to 500°C. The ordered LiMnPO4 olivine structure without any impurity phase could be identified by X-ray diffraction analysis for all samples. It could be also confirmed from scanning electron microscopy and transmission electron

Izumi Taniguchi

2011-01-01

134

Preparation of carbon coated LiMnPO 4 powders by a combination of spray pyrolysis with dry ball-milling followed by heat treatment  

Microsoft Academic Search

Nanostructured LiMnPO4 particles could be successfully synthesized by an ultrasonic spray pyrolysis method from the precursor solution; LiNO3, Mn(NO3)2·6H2O and H3PO4 were stoichiometrically dissolved into distilled water. The X-ray diffraction analysis showed that the as-prepared powders which had the desired olivine structure without any impurity phase could be obtained in the reactor temperatures ranging from 500 to 800°C. Carbon coated

Zhumabay Bakenov; Izumi Taniguchi

2010-01-01

135

Rapid synthesis of spherical-shaped green-emitting MgGa{sub 2}O{sub 4}:Mn{sup 2+} phosphor via spray pyrolysis  

SciTech Connect

Simple, one-step synthesis of spherical-shaped powder phosphors with aqueous precursors via a spray pyrolysis method is reported. Green-emitting MgGa{sub 2}O{sub 4}:Mn{sup 2+} phosphor with a controlled shape was successfully obtained by spraying under a reductive atmosphere (N{sub 2} + H{sub 2} carrier gas) without high-temperature post-heat treatment. In addition, the corresponding powder phosphors were well dispersed and showed a clean surface morphology compared to an existing cumbersome process using high-temperature post-annealing. The new method may help to prevent surface residual non-radiative defect sites. The result of highly luminescent and spherical morphology, non-aggregated powder phosphor by this procedure holds promise for a cost-effective and rapid synthesis process for conventional inorganic phosphors.

Choi, Sungho, E-mail: shochoi@krict.re.kr [Advanced Materials Division, Korea Research Institute of Chemical Technology, P.O. Box 107, Yuseong, Daejeon 305-600 (Korea, Republic of)] [Advanced Materials Division, Korea Research Institute of Chemical Technology, P.O. Box 107, Yuseong, Daejeon 305-600 (Korea, Republic of); Kim, Kyoungun [Dongbu Fine Chemicals Co., Ltd. 623 Seonggok-dong, Danwon-gu, Ansan-si, Gyeonggi-do, 423-833 (Korea, Republic of)] [Dongbu Fine Chemicals Co., Ltd. 623 Seonggok-dong, Danwon-gu, Ansan-si, Gyeonggi-do, 423-833 (Korea, Republic of); Moon, Young-Min [LED Research Center, LED PKG Development Group, LG Innotek Co., Ltd. 533 Hogye 1-dong, Dongan-gu, Anyang-si, Gyeonggi-do, 431-831 (Korea, Republic of)] [LED Research Center, LED PKG Development Group, LG Innotek Co., Ltd. 533 Hogye 1-dong, Dongan-gu, Anyang-si, Gyeonggi-do, 431-831 (Korea, Republic of); Park, Byung-Yoon; Jung, Ha-Kyun [Advanced Materials Division, Korea Research Institute of Chemical Technology, P.O. Box 107, Yuseong, Daejeon 305-600 (Korea, Republic of)] [Advanced Materials Division, Korea Research Institute of Chemical Technology, P.O. Box 107, Yuseong, Daejeon 305-600 (Korea, Republic of)

2010-08-15

136

Synthesis of (La,Sr)MnOâ-YSZ composite particles by spray pyrolysis  

Microsoft Academic Search

The authors have been developing a cathode material for solid oxide fuel cells (SOFCs) by the pyrolysis method. The unit cell of SOFCs consists of two porous and gas diffusion electrodes (cathode and anode) separated by a dense electrolyte such as yttria-stabilized zirconia (YSZ), which has a high ionic conductivity. Generally, the perovskite (La,Sr)MnOâ has been used mostly as a

Takehisa Fukui; Takeshi Oobuchi; Yumi Ikuhara; Satoshi Ohara; Kaseki Kodera

1997-01-01

137

The effects of calcination temperature on the electrochemical performance of LiMnPO 4 prepared by ultrasonic spray pyrolysis  

Microsoft Academic Search

Carbon-coated LiMnPO4 powders were prepared by ultrasonic spray pyrolysis. The effects of calcination temperature on the microstructure and electrochemical performance of C-LiMnPO4 were investigated. X-ray diffraction (XRD) studies showed that the crystallite size varied with calcination temperature. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations revealed that the calcination temperature had a strong influence on the morphology of

Seung-Min Oh; Sung Woo Oh; Seung-Taek Myung; Sung-Man Lee; Yang-Kook Sun

2010-01-01

138

Nano-sized Spherical MgB 2 Superconducting Powder Fabrication Using MHz Range Ultrasonic Spray Pyrolysis (USP) System  

Microsoft Academic Search

We have fabricated 40–150 nm sized MgB2 superconducting spherical powders by using a 2.4 MHz ultrasonic spray pyrolysis system and consecutive high temperature heating\\u000a and powder collection chamber. Various chemical solutions, which contain Mg, B, de-ionized water, acetone and LAPSA in different\\u000a concentrations and gas atmosphere, were used to obtain MgB2 superconducting powders. Microstructural, transport and magnetic characterizations of the powders were

M. E. Yakinci; M. A. Aksan; Y. Balci; S. Altin; Y. Onal; Y. Aydogdu

2011-01-01

139

Fabrication of LiCoO 2 thin film cathodes for rechargeable lithium battery by electrostatic spray pyrolysis  

Microsoft Academic Search

LiCoO2 thin films for cathodes in rechargeable lithium batteries were prepared by the electrostatic spray pyrolysis technique. The surface morphology may be either dense or porous, depending on the process conditions. Low temperature (280 °C) results in amorphous films. Deposition at a temperature higher than 340 °C results in the hexagonal phase of LiCoO2. The lithium chemical diffusion coefficients of

C. H. Chen; A. A. J. Buysman; E. M. Kelder; J. Schoonman

1995-01-01

140

Processing and synthesis of multi-metallic nano oxide ceramics via liquid-feed flame spray pyrolysis  

Microsoft Academic Search

The liquid-feed flame spray pyrolysis (LF-FSP) process aerosolizes metal-carboxylate precursors dissolved in alcohol with oxygen and combusts them at >1500°C. The products are quenched rapidly (˜10s msec) to < 400°C. By selecting the appropriate precursor mixtures, the compositions of the resulting oxide nanopowders can be tailored easily, which lends itself to combinatorial studies of systems facilitating material property optimization. The

Jose Antonio Azurdia

2009-01-01

141

Polycrystalline RbTiOPO 4 and KTiOPO 4 bilayer thin films by spray pyrolysis  

Microsoft Academic Search

A novel titanium precursor has been used with spray pyrolysis (SP) to deposit polycrystalline rubidium titanyl phosphate, RbTiOPO4 (RTP), thin films on thin film potassium titanyl phosphate, KTiOPO4 (KTP), for possible waveguide applications. The titanium precursor for this process was titanium peroxo–hydroxo complex (TPH) in aqueous diluted HNO3. The morphology of thin films of RTP and KTP depended on the

Nickolay Golego; Michael Cocivera

1998-01-01

142

Green photoluminescence efficiency and free-carrier density in ZnO phosphor powders prepared by spray pyrolysis  

Microsoft Academic Search

Electron paramagnetic resonance, optical absorption, and photoluminescence spectroscopy have been combined to characterize ZnO powders that were prepared by spray pyrolysis. We generally observe a good correlation between the 510 nm green emission intensity and the density of paramagnetic isolated oxygen vacancies. In addition, both quantities increase with free-carrier concentration ne, as long as ne < 1.4 × 1018cm?3. At

K. Vanheusden; C. H. Seager; W. L. Warren; D. R. Tallant; J. Caruso; M. J. Hampden-Smith; T. T. Kodas

1997-01-01

143

Photoluminescence and photoelectrochemical properties of nanocrystalline ZnO thin films synthesized by spray pyrolysis technique  

NASA Astrophysics Data System (ADS)

A simple and inexpensive spray pyrolysis technique (SPT) was employed for the synthesis of nanocrystalline zinc oxide (ZnO) thin films onto soda lime glass and tin doped indium oxide (ITO) coated glass substrates at different substrate temperatures ranging from 300 °C to 500 °C. The synthesized films were polycrystalline, with a (0 0 2) preferential growth along c-axis. SEM micrographs revealed the uniform distribution of spherical grains of about 80-90 nm size. The films were transparent with average visible transmittance of 85% having band gap energy 3.25 eV. All the samples exhibit room temperature photoluminescence (PL). A strong ultraviolet (UV) emission at 398 nm with weak green emission centered at 520 nm confirmed the less defect density in the samples. Moreover, the samples are photoelectrochemically active and exhibit the highest photocurrent of 60 ?A, a photovoltage of 280 mV and 0.23 fill factor (FF) for the Zn 450 films in 0.5 M Na 2SO 4 electrolyte, when illuminated under UV light.

Tarwal, N. L.; Shinde, V. V.; Kamble, A. S.; Jadhav, P. R.; Patil, D. S.; Patil, V. B.; Patil, P. S.

2011-10-01

144

Synthesis of MgO/ZnO Nanocomposites by Flame Spray Pyrolysis  

NASA Astrophysics Data System (ADS)

Flame Spray Pyrolysis (FSP) was used to synthesize MgO/ZnO nanocomposites with different MgO doping levels ranging from 5-20 wt%MgO. Zinc naphthenate and magnesium acetate tetrahydrate dissolved in ethanol were used as Zn and Mg precursors, respectively. The phase and crystallinity were analyzed by X-ray diffraction (XRD). The high specific surface area (SSABET) of the nanocomposites was measured by nitrogen adsorption (BET analysis). The sizes and morphologies of the nanocomposites were further investigated by transmission electron microscopy (TEM). The crystallite sizes of ZnO spheroidal and hexagonal particles were found to be ranging from 5-20 nm. XRD patterns revealed the MgxZn1-xO nanocomposite structure with 0.1

Samerjai, T.; Liewhiran, C.; Phanichphant, S.

2009-07-01

145

Synthesis of electrochromic vanadium oxide by pulsed spray pyrolysis technique and its properties  

NASA Astrophysics Data System (ADS)

A new improved pulsed spray pyrolysis technique (PSPT) was employed to deposit a vanadium oxide (V2O5) thin film from a methanolic vanadium chloride precursor onto glass and conducting F : SnO2 coated glass substrates. The structural, morphological, electrical, optical and spectroscopic properties of the film deposited at 573 K were studied. Infrared spectroscopy and x-ray diffraction confirmed the presence of the V2O5 phase. The V2O5 film (thickness ~118 nm) is polycrystalline with a tetragonal crystal structure. Scanning electron microscopy reveals compact granular morphology consisting of ~80-100 nm size grains. The film is transparent in the visible region (average %T ~70%) with an optical band gap energy of 2.47 eV involving both direct and indirect optical transitions. The room temperature electrical resistivity (conductivity) of the film is 1.6 × 108 ? cm (6.25 × 10-9 S cm-1) with an activation energy of 0.67 eV in the temperature range 300-550 K. It exhibited cathodic electrochromism in the lithium containing electrolyte (0.5 M LiClO4 + propylene carbonate).

Patil, C. E.; Tarwal, N. L.; Shinde, P. S.; Deshmukh, H. P.; Patil, P. S.

2009-01-01

146

CTAB assisted growth and characterization of nanocrystalline CuO films by ultrasonic spray pyrolysis technique  

NASA Astrophysics Data System (ADS)

An aqueous solution of cupric nitrate trihydrate (Cu(NO 3) 2·3H 2O) modified with cetyltrimetylammonium bromide (CTAB) is used to deposit CuO films on glass substrate by chemical spray pyrolysis technique. The thermal analysis shows that the dried CTAB doped precursor decomposes by an exothermic reaction and suggests that minimum substrate temperature for film deposition should be greater than 270 °C. X-ray diffraction (XRD) studies indicate the formation of monoclinic CuO with preferential orientation along (0 0 2) plane for all film samples. The CTAB used as cationic surfactant in precursor results in the suppression of grain growth in films along the (1 1 0), (0 2 0) and (2 2 0) crystal planes of CuO. Surfactant modified films showed an increase in crystallite size of 14 nm at substrate temperature of 300 °C. The scanning electron micrographs (FESEM) confirm the uniform distribution of facets like grains on the entire area of substrate. CTAB modified films show a significant reduction in the particle agglomeration. Electrical studies of the CuO films deposited at substrate temperature of 300 °C with and without surfactant reveal that the CTAB doping increase the activation energy of conduction by 0.217 eV and room temperature response to ammonia by 9%. The kinetics of the ammonia gas adsorption on the film surface follows the Elovich and Diffusion models.

Singh, Iqbal; Kaur, Gursharan; Bedi, R. K.

2011-09-01

147

Gas sensing properties of zinc oxide thin films prepared by spray pyrolysis  

NASA Astrophysics Data System (ADS)

Metal oxide semiconductors are widely employed as potential materials for the development of sensing devices for poisonous and inflammable gases. The change in resistivity of active material is exploited as a sensing parameter. A large volume of research work has been carried out in the last few decades on sensors and potential sensor materials. The advent of nanostructured materials has given a new impetus to the sensor research. Preparation and sensing response of zinc oxide thin films towards alcohol has been reported in this paper. Zinc oxide thin film has been prepared by using spray pyrolysis, using zinc acetate and methanol as the starting materials. The thin film was characterized for morphology and structure by using x-ray diffractometer (XRD) and field emission scanning electron microscope (FESEM) techniques. The results indicated that the ZnO particles are crystallized in the wurtzite hexagonal phase, which were well distributed in the films. Prepared zinc oxide thin film was exposed to different alcohols to check its gas sensing behaviour at different temperatures.

Singh, Onkar; Kohli, Nipin; Singh, Manmeet Pal; Anand, Kanika; Singh, Ravi Chand

2012-06-01

148

Comparative study of ITO and FTO thin films grown by spray pyrolysis  

SciTech Connect

Tin doped indium oxide (ITO) and fluorine doped tin oxide (FTO) thin films have been prepared by one step spray pyrolysis. Both film types grown at 400 deg. C present a single phase, ITO has cubic structure and preferred orientation (4 0 0) while FTO exhibits a tetragonal structure. Scanning electron micrographs showed homogeneous surfaces with average grain size around 257 and 190 nm for ITO and FTO respectively. The optical properties have been studied in several ITO and FTO samples by transmittance and reflectance measurements. The transmittance in the visible zone is higher in ITO than in FTO layers with a comparable thickness, while the reflectance in the infrared zone is higher in FTO in comparison with ITO. The best electrical resistivity values, deduced from optical measurements, were 8 x 10{sup -4} and 6 x 10{sup -4} {Omega} cm for ITO (6% of Sn) and FTO (2.5% of F) respectively. The figure of merit reached a maximum value of 2.15 x 10{sup -3} {Omega}{sup -1} for ITO higher than 0.55 x 10{sup -3} {Omega}{sup -1} for FTO.

Ait Aouaj, M. [Laboratory of Materials Physics, University of Mohammed V-Agdal, Rabat (Morocco); Diaz, R. [Departamento de Fisica Aplicada C-XII, Universidad Autonoma de Madrid, Madrid (Spain); Belayachi, A. [Laboratory of Materials Physics, University of Mohammed V-Agdal, Rabat (Morocco); Rueda, F. [Departamento de Fisica Aplicada C-XII, Universidad Autonoma de Madrid, Madrid (Spain); Abd-Lefdil, M., E-mail: a-lefdil@fsr.ac.ma [Laboratory of Materials Physics, University of Mohammed V-Agdal, Rabat (Morocco)

2009-07-01

149

Nitrogen-doped carbon nanotubes with tunable structure and high yield produced by ultrasonic spray pyrolysis  

NASA Astrophysics Data System (ADS)

Nitrogen-doped carbon nanotubes (CN x) were prepared by ultrasonic spray pyrolysis from mixtures of imidazole and acetonitrile. Imidazole, as an additive, was used to control the structure and nitrogen doping in CN x by adjusting its concentration in the mixtures. Scanning electron microscopy observation showed that the addition of imidazole increased the nanotube growth rate and yield, while decreased the nanotube diameter. Transmission electron microscopy study indicated that the addition of imidazole promoted the formation of a dense bamboo-like structure in CN x. X-ray photoelectron spectroscopy analysis demonstrated that the nitrogen content varied from 3.2 to 5.2 at.% in CN x obtained with different imidazole concentrations. Raman spectra study showed that the intensity ratio of D to G bands gradually increased, while that of 2D to G bands decreased, due to increasing imidazole concentration. The yield of CN x made from mixtures of imidazole and acetonitrile can reach 192 mg in 24 min, which is 15 times that of CN x prepared from only acetonitrile. The aligned CN x, with controlled nitrogen doping, tunable structure and high yield, may find applications in developing non-noble catalysts and novel catalyst supports for fuel cells.

Liu, Jian; Zhang, Yong; Ionescu, Mihnea Ioan; Li, Ruying; Sun, Xueliang

2011-06-01

150

Synthesis and characterization of thorium phosphate phases by spray pyrolysis: chemistry of thorium phosphates  

SciTech Connect

This paper describes the synthesis of some thorium phosphate compounds with different Th/P ratio (1/2, 2/3 and 3/4) by a spray pyrolysis technique. The so-prepared rough compounds were annealed at different temperatures for 2 h and then analyzed by mainly X-ray diffraction on powder and infrared spectroscopy. Every rough compound is composed by very badly crystallized ThO{sub 2} phase polluted by carbon residue. An annealing treatment at 800 deg. C leads to the thorium diphosphate phase, {alpha}-ThP{sub 2}O{sub 7} in every case. At 900 deg. C, such a phase is decomposed into a thorium phosphate diphosphate phase (Th{sub 4}(PO{sub 4}){sub 4}P{sub 2}O{sub 7}, called TPD). However, a thorium excess in the initial mixture (Th/P = 3/4) leads also to observe the ThO{sub 2} phase. The TPD phase is stable up to 1200 deg. C and does not react with the ThO{sub 2} compound. Beyond 1200 deg. C, the TPD phase is slowly decomposed into a thorium phosphate compound which should be a thorium oxide phosphate; this compound does not contain any diphosphate species.

Marchin, L.; Trombe, J.C.; Verelst, M

2004-10-04

151

Synthesis and characterization of Mo doped SnO2 thin films with spray pyrolysis  

NASA Astrophysics Data System (ADS)

Tin oxide thin films doped with different Mo content were successfully grown by spray pyrolysis and they were characterized as a function of Mo content, changed from 0 to 3.5 at.% with 0.5 at.% step. The XRD studies showed that the films had SnO2 cassiterite structure with (2 1 1) preferential orientation and the best crystal properties was observed for 2 at.% Mo doped sample. The SEM images indicated the films were made up of nanosized grains and it was observed pyramidal, polyhedron shaped grains on the deposited films' surfaces. From electrical and optical studies, although 2 at.% Mo doped SnO2 film exhibited the lowest sheet resistance (39.81 ?) and the highest IR reflective (81.77%), 1 at.% Mo doped film has the highest optical band gap (4.011 eV). The lowest Urbach energy (293 meV) and the highest figure of merit (1.80 × 10?3 ??1) values were observed for 0.5 at.% Mo doped sample between all films. The results found in present study showed that Mo doped SnO2 thin films is a good candidate for solar cells, IR coating and other optoelectronic and technological applications.

Turgut, Güven; Sönmez, Erdal

2014-05-01

152

Morphology control and luminescence properties of BaMgAl{sub 10}O{sub 17}:Eu{sup 2+} phosphors prepared by spray pyrolysis  

SciTech Connect

Starting from the aqueous solutions of metal nitrates with citric acid and polyethylene glycol (PEG) as additives, BaMgAl{sub 10}O{sub 17}:Eu{sup 2+} (BAM:Eu{sup 2+}) phosphors were prepared by a two-step spray pyrolysis (SP) method. X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence spectra were used to characterize the resulted BAM:Eu{sup 2+} phosphors. The obtained BAM:Eu{sup 2+} phosphor particles have spherical shape, submicron size (0.5-3{mu}m). The effects of process conditions of the spray pyrolysis, such as molecular weight and concentration of PEG, on the morphology and luminescence properties of phosphor particles were investigated. Adequate amount of PEG was necessary for obtaining spherical particles, and the optimum emission intensity could be obtained when the concentration of PEG was 0.03g/ml in the precursor solution. Moreover, the emission intensity of the phosphors increased with increasing of metal ion concentration in the solution. Compared with the BAM:Eu{sup 2+} phosphor prepared by citrate-gel method, spherical BAM:Eu{sup 2+} phosphor particles showed a higher emission intensity.

Zhou Yonghui [Key Laboratory of Rare Earth Chemistry and Physics, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Number 5625, Remin Street, Changchun city, Jilin Province 130022 (China); Lin Jun [Key Laboratory of Rare Earth Chemistry and Physics, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Number 5625, Remin Street, Changchun city, Jilin Province 130022 (China)]. E-mail: jlin@ns.ciac.jl.cn

2005-02-15

153

Fourier transform infrared and Raman spectroscopic properties of Cd1-xSbxS films deposited by ultrasonic spray pyrolysis  

NASA Astrophysics Data System (ADS)

Cd1-xSbxS films (x = 0.0, 0.1 and 0.2) were deposited by the ultrasonic spray pyrolysis method. The films were deposited on glass substrates at temperatures of 300 °C. The effect of antimony doping on the structural and vibrational (FT-IR and Raman) properties of cadmium sulphide films were examined. Structural investigations of the films showed the hexagonal polycrystalline structure and that the incorporation of antimony leads to substantial changes in the structural characteristics of CdS films. The preferential orientation of the Cd1-xSbxS films shifts from (002) to (101) with increasing x values. The Raman spectrum for CdS films is dominated by an intense band at 301.5 cm-1(1LO) assigned to the first-order longitudinal optic phonon and the second-order phonon peak 598.5 cm-1 (2LO). Cd1-xSbxS films have been prepared and their FT-IR (400-4000 cm-1) spectra are reported for the first time. The vibrations at 550-1164 cm-1 are caused by Cd-S and C-O stretching vibrations.

Özer, T.; Aksay, S.; Köse, S.

2010-07-01

154

Magnetic/luminescent core/shell particles synthesized by spray pyrolysis and their application in immunoassays with internal standard.  

PubMed

Many types of fluorescent nanoparticles have been investigated as alternatives to conventional organic dyes in biochemistry; magnetic beads also have a long history of biological applications. In this work we apply flame spray pyrolysis in order to engineer a novel type of nanoparticle that has both luminescent and magnetic properties. The particles have magnetic cores of iron oxide doped with cobalt and neodymium and luminescent shells of europium-doped gadolinium oxide (Eu:Gd(2)O(3)). Measurements by vibrating sample magnetometry showed an overall paramagnetic response of these composite particles. Luminescence spectroscopy showed spectra typical of the Eu ion in a Gd(2)O(3) host-a narrow emission peak centred near 615 nm. Our synthesis method offers a low-cost, high-rate synthesis route that enables a wide range of biological applications of magnetic/luminescent core/shell particles. Using these particles we demonstrate a novel immunoassay format with internal luminescent calibration for more precise measurements. PMID:18974844

Dosev, Dosi; Nichkova, Mikaela; Dumas, Randy K; Gee, Shirley J; Hammock, Bruce D; Liu, Kai; Kennedy, Ian M

2007-07-01

155

Characteristics of Eu 2+-doped Ca-?-SiAlON phosphor powders prepared by spray pyrolysis process  

NASA Astrophysics Data System (ADS)

Eu 2+-doped Ca-?-SiAlON phosphor powders with fine size and regular morphology were prepared by combining spray pyrolysis and the carbothermal reduction and nitridation processes. The precursor powders were prepared by spray pyrolysis from the spray solution with ethylenediaminetetraacetic acid, citric acid, and sucrose; they had large sizes, were hollow, and had thin wall structures. The precursor powders containing a carbon component turned into Ca-?-SiAlON phosphor powders after firing at 1450 °C under a H 2/N 2 mixture gas. The mean size of the phosphor powders was 5.1 ?m. The phosphor powders had a broad excitation spectra range of 250-500 nm; this consisted of two broadbands centered at 305 and 400 nm. When excited by a 455-nm blue light, the emission spectra of the phosphor powders displayed a broadband in the range of 500-700 nm, which resulted in a yellow emission. The wavelength of the emission spectrum showing the maximum intensity was 576 nm.

Lee, Sang Ho; Yi, Jang Heui; Kim, Jung Hyun; Ko, You Na; Kang, Yun Chan

2011-01-01

156

Effect of calcination temperature on morphology, crystallinity and electrochemical properties of nano-crystalline metal oxides (Co 3O 4, CuO, and NiO) prepared via ultrasonic spray pyrolysis  

Microsoft Academic Search

Nano-crystalline metal oxides (Co3O4, CuO, and NiO) are synthesized as anode materials for lithium-ion batteries by an ultrasonic spray pyrolysis method. The effects of calcination temperature on the morphology, crystallite size and electrochemical properties of the metal oxides are investigated. X-ray diffraction (XRD) studies show that the crystallite size varies with the final calcination temperature. Scanning electron microscopy (SEM) and

Sung Woo Oh; Hyun Joo Bang; Young Chan Bae; Yang-Kook Sun

2007-01-01

157

Magneto-optical characteristics of Mn-doped ZnO films deposited by ultrasonic spray pyrolysis  

Microsoft Academic Search

This work considers a Mn-doped ZnO (ZnO:Mn) film deposited on a slide glass substrate by ultrasonic spray pyrolysis. ZnO:Mn (Mn at 1.5at%) film with and without an applied magnetic field, is demonstrated to have absorption edges at 2.74 and 2.84eV, respectively. These values are lower than that of a pure ZnO film because the Mn-doping causes the exchange of s–d

Lung-Chien Chen; Ching-Ho Tien; Chia-Shien Fu

158

Growth and Characterization of Co-Doped Fluorine and Antimony in Tin Oxide Thin Films Obtained by Ultrasonic Spray Pyrolysis  

Microsoft Academic Search

Fluorine (F)-doped, antimony (Sb)-doped, fluorine and antimony co-doped tin oxide (SnO2) thin films were prepared by ultrasonic spray pyrolysis technique using SnCl2, NH4F and SbCl3 as precursors of Sn, F and Sb elements respectively. F and Sb doping concentrations carried out from 1 to 20 wt% and 1 to 4 wt% in F-doped and Sb-doped SnO2 films respectively. In F

Thitinai Gaewdang; Ngamnit Wongcharoen

2007-01-01

159

Low oxygen biomass-derived pyrolysis oils and methods for producing the same  

DOEpatents

Low oxygen biomass-derived pyrolysis oils and methods for producing them from carbonaceous biomass feedstock are provided. The carbonaceous biomass feedstock is pyrolyzed in the presence of a catalyst comprising base metal-based catalysts, noble metal-based catalysts, treated zeolitic catalysts, or combinations thereof to produce pyrolysis gases. During pyrolysis, the catalyst catalyzes a deoxygenation reaction whereby at least a portion of the oxygenated hydrocarbons in the pyrolysis gases are converted into hydrocarbons. The oxygen is removed as carbon oxides and water. A condensable portion (the vapors) of the pyrolysis gases is condensed to low oxygen biomass-derived pyrolysis oil.

Marinangeli, Richard; Brandvold, Timothy A; Kocal, Joseph A

2013-08-27

160

Preparation of mesoporous alumina particles by spray pyrolysis and application to double bond migration of 2-butene.  

PubMed

The objective of the present study is to investigate the catalytic performance of mesoporous alumina that were prepared via spray pyrolysis for double bond migration from 2-butene to 1-butene. The mesoporous alumina particles were prepared via spray pyrolysis by changing the types of organic surfactants and Al precursors. The texture and acidic properties of mesoporous alumina were analyzed through N2 adsorption, SEM, ammonia-temperature programmed desorption, and FT-IR of adsorbed pyridine. The morphologies and texture properties of the mesoporous alumina were found to have been strongly influenced by the combination of the Al precursor and the structure-directing agents. The mesoporous alumina samples had two kinds of acidic sites: a Lewis acid site and a H-bonded weak acid site. 1-Butene was produced selectively through double bond migration of 2-butene over all of the mesoporous alumina catalysts. The catalyst prepared by using a chloride compound as an aluminium precursor and CTAC as a structure-directing agent showed the highest activity in the double bond migration of 2-butene, which was attributed to its large surface area and an overall high amount of acid sites. PMID:22121707

Song, Ki Chang; Kim, Joo Hyun; Kim, Jin Han; Jung, Kyeong Youl; Park, Young-Kwon; Jeon, Jong-Ki

2011-07-01

161

High-rate production of functional nanostructured films and devices by coupling flame spray pyrolysis with supersonic expansion.  

PubMed

The fabrication of functional thin films and devices by direct deposition of nanoparticles from the gas phase is a promising approach enabling, for instance, the integration of complex analytical and sensing capabilities on microfabricated platforms. Aerosol-based techniques ensure large-scale nanoparticle production and they are potentially suited for this goal. However, they are not adequate in terms of fine control over the lateral resolution of the coatings, mild processing conditions (avoiding high temperature and aggressive chemicals), low contamination and compatibility with microfabrication processes. Here we report the high-rate and efficient production of functional nanostructured films by nanoparticle assembling obtained by the combination of flame spray pyrolysis and supersonic expansion. Our approach merges the advantages of flame spray pyrolysis for bulk nanopowders such as process stability and wide material library availability with those of supersonic cluster beam deposition in terms of lateral resolution and of direct integration of nanomaterials on devices. We efficiently produced nanostructured films and devices (such as gas sensors) using metal oxide, pure noble metal and oxide-supported noble metal nanoparticles. PMID:22516767

Wegner, K; Vinati, S; Piseri, P; Antonini, A; Zelioli, A; Barborini, E; Ducati, C; Milani, P

2012-05-11

162

Leidenfrost temperature related CVD-like growth mechanism in ZnO-TFTs deposited by pulsed spray pyrolysis  

NASA Astrophysics Data System (ADS)

Zinc oxide thin films were prepared by pulsed spray pyrolysis (SP) from aqueous zinc acetate precursor solution. The deposition behavior of the solution with regard to the pool boiling curve of the solvent was investigated to gain insights of the deposition mechanism which leads to homogeneous and reproducible ZnO layers. The Leidenfrost effect was found to play an important role since the Leidenfrost temperature has to be exceeded to form high quality layers. It is concluded that 3D nucleation of ZnO nano-crystals takes place out of the gaseous phase by a CVD-like process on ITO as well as on SiO2 substrates. Crystal orientation and surface roughness of the zinc oxide layer are found to depend strongly on the substrate. An increasing grain size with film thickness is observed. These findings were utilized to fabricate and investigate the semiconducting properties of the films in ZnO thin film transistors (TFTs). The mobility exceeded 12 cm2 V-1 s-1, the on-set was at 1 V and the on-off current ratio was found to be higher than 108. Hence the morphology and the electrical parameters of the ZnO films deposited by pulsed spray pyrolysis from non-toxic aqueous zinc acetate solution above the Leidenfrost point show excellent properties for electronic applications.

Ortel, Marlis; Wagner, Veit

2013-01-01

163

Modifying Optical Properties of ZnO Films by Forming Zn[subscript 1-x] Co[subscript x]O Solid Solutions via Spray Pyrolysis  

ERIC Educational Resources Information Center

A simple and cost-effective experiment for the development and characterization of semiconductors using Uv-vis spectroscopy is described. The study shows that the optical properties of ZnO films can be easily modified by forming Zn[subscript 1-x] Co[subscript x]O solid solutions via spray pyrolysis.

Bentley, Anne K.; Weaver, Gabriela C.; Russell, Cianan B.; Fornes, William L.; Choi, Kyoung-Shin; Shih, Susan M.

2007-01-01

164

Effect of the substrate temperature on the physical properties of molybdenum tri-oxide thin films obtained through the spray pyrolysis technique  

SciTech Connect

Polycrystalline molybdenum tri-oxide thin films were prepared using the spray pyrolysis technique; a 0.1 M solution of ammonium molybdate tetra-hydrated was used as a precursor. The samples were prepared on Corning glass substrates maintained at temperatures ranging between 423 and 673 K. The samples were characterized through micro Raman, X-ray diffraction, optical transmittance and DC electrical conductivity. The species MoO{sub 3} (H{sub 2}O){sub 2} was found in the sample prepared at a substrate temperature of 423 K. As the substrate temperature rises, the water disappears and the samples crystallize into {alpha}-MoO{sub 3}. The optical gap diminishes as the substrate temperature rises. Two electrical transport mechanisms were found: hopping under 200 K and intrinsic conduction over 200 K. The MoO{sub 3} films' sensitivity was analyzed for CO and H{sub 2}O in the temperature range 160 to 360 K; the results indicate that CO and H{sub 2}O have a reduction character. In all cases, it was found that the sensitivity to CO is lower than that to H{sub 2}O. - Highlights: Black-Right-Pointing-Pointer A low cost technique is used which produces good material. Black-Right-Pointing-Pointer Thin films are prepared using ammonium molybdate tetra hydrated. Black-Right-Pointing-Pointer The control of the physical properties of the samples could be done. Black-Right-Pointing-Pointer A calculation method is proposed to determine the material optical properties. Black-Right-Pointing-Pointer The MoO{sub 3} thin films prepared by spray pyrolysis could be used as gas sensor.

Martinez, H.M. [Grupo de Materiales con Aplicaciones Tecnologicas, Departamento de Fisica Universidad Nacional de Colombia sede Bogota (Colombia)] [Grupo de Materiales con Aplicaciones Tecnologicas, Departamento de Fisica Universidad Nacional de Colombia sede Bogota (Colombia); Torres, J., E-mail: njtorress@unal.edu.co [Grupo de Materiales con Aplicaciones Tecnologicas, Departamento de Fisica Universidad Nacional de Colombia sede Bogota (Colombia); Lopez Carreno, L.D. [Grupo de Materiales con Aplicaciones Tecnologicas, Departamento de Fisica Universidad Nacional de Colombia sede Bogota (Colombia)] [Grupo de Materiales con Aplicaciones Tecnologicas, Departamento de Fisica Universidad Nacional de Colombia sede Bogota (Colombia); Rodriguez-Garcia, M.E. [Departamento de Nanotecnologia, Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, Campus Juriquilla, Queretaro, Qro., Mexico (Colombia)] [Departamento de Nanotecnologia, Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, Campus Juriquilla, Queretaro, Qro., Mexico (Colombia)

2013-01-15

165

Effect of the flame temperature on the characteristics of zirconium oxide fine particle synthesized by flame assisted spray pyrolysis  

NASA Astrophysics Data System (ADS)

Zirconium oxide fine particles were synthesized by flame assisted spray pyrolysis using zirconium chloride solution as precursor. Propane gas and air were used as a fuel and an oxidizer, respectively. The ratio of flow rate of oxidizer and fuel was maintained constant at 10:1 to ensure a complete combustion. Increasing fuel flow rate led to the increase of temperature distribution in the flame reactor. The intensity of XRD patterns increased with temperature and precursor concentration. Phase composition of zirconium oxide produced by this process consisted of monoclinic and tetragonal phases. The volume fraction of monoclinic phase of zirconium oxide increased with temperature and precursor concentration. The morphology particles observed by SEM resulted in spherical particles with size in the submicron range depending on the precursor concentration.

Widiyastuti, W.; Machmudah, Siti; Nurtono, Tantular; Winardi, Sugeng

2013-09-01

166

Structural, optical, electrical and surface properties of Co-doped ZnO films prepared by spray pyrolysis  

NASA Astrophysics Data System (ADS)

In this study undoped and Co-doped ZnO films were prepared by ultrasonic spray pyrolysis technique. Co-doped ZnO films were obtained on glass substrates at different Co concentrations (at 2%, 4%) using zinc acetate and cobalt chloride as precursors. The effect of Co doping was investigated on the structural, optical, electrical and surface properties. The structural and physical properties of the films were studied by using X-Ray Diffraction (XRD), Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDX), Spectroscopic Ellipsometry, UV-VIS Spectrophotometry and four-point probe techniques. Consequently available potential of Co doped ZnO films for technological applications was searched.

Gency?lmaz, O.; Atay, F.; Akyuz, I.

2012-09-01

167

Optical, electrical and surface properties of annealed CdO:Mg thin films prepared by spray pyrolysis  

NASA Astrophysics Data System (ADS)

The use of transparent conducting oxides in optoelectronic and photovoltaic devices has encouraged research on this field in recent years. Especially, cadmium oxide is a promising material for solar cell application but also for photodiodes and gas sensors. Mg doped CdO (CdO:Mg) films have been prepared on glass substrates by the ultrasonic spray pyrolysis (USP) technique. After the production, the films have been annealed in air atmosphere at 475°C and half hour. Results on surface, optical and electrical properties of the films as a function of the thermal annealing have been reported. Thicknesses of the films have been determined by the filmetrics thin film measurement system. Transmission and absorbance spectra have been taken by UV-vis spectrophotometer. Atomic Force Microscopy (AFM) analysis indicates that the roughness of the surface decreases upon increasing Mg concentration. The minimum resistivity value of the films was 2×10-3 ? cm.

Karakaya, Seniye; Ozbas, Omer

2013-12-01

168

XRD and XPS characterization of mixed valence Mn 3O 4 hausmannite thin films prepared by chemical spray pyrolysis technique  

NASA Astrophysics Data System (ADS)

Spray pyrolysis technique has been employed successfully for the synthesis of single phase mixed valence spinel hausmannite (Mn 3O 4) thin films using alcoholic start solution of manganese acetate (Mn(CH 3COO) 2·4H 2O) on pyrex glass substrates at atmospheric pressure using air as a carrier gas. Thermal decomposition of the precursor in the temperature range 320-490 °C led to the formation of Mn 3O 4 phase as revealed from the thermogravimetry analysis. Prepared samples are characterized by X-ray diffraction that shows spinel structure with space group I4 1/ amd. Pure and well crystallized specimen is subjected to X-ray photoelectron spectroscopy for the surface chemistry investigation of these systems at a molecular level. Surface Mn/O ratio is compared to the bulk composition of the sample. Atomic force micrographs revealed that the morphology and the surface grains of the films largely influenced by the substrate temperature.

Moses Ezhil Raj, A.; Victoria, S. Grace; Jothy, V. Bena; Ravidhas, C.; Wollschläger, Joachim; Suendorf, M.; Neumann, M.; Jayachandran, M.; Sanjeeviraja, C.

2010-02-01

169

Visible light-induced water oxidation on mesoscopic alpha-Fe2O3 films made by ultrasonic spray pyrolysis.  

PubMed

Alpha-Fe(2)O(3) films having a mesoscopic leaflet type structure were produced for the first time by ultrasonic spray pyrolysis (USP) to explore their potential as oxygen-evolving photoanodes. The target of these studies is to use translucent hematite films deposited on conducting fluorine doped tin oxide (FTO) glass as top electrodes in a tandem cell that accomplishes the cleavage of water into hydrogen and oxygen by sunlight. The properties of layers made by USP were compared to those deposited by conventional spray pyrolysis (SP). Although both types of films show similar XRD and UV-visible and Raman spectra, they differ greatly in their morphology. The mesoscopic alpha-Fe(2)O(3) layers produced by USP consist mainly of 100 nm-sized platelets with a thickness of 5-10 nm. These nanosheets are oriented mainly perpendicularly to the FTO support, their flat surface exposing (001) facets. The mesoscopic leaflet structure has the advantage that it allows for efficient harvesting of visible light, while offering at the same time the very short distance required for the photogenerated holes to reach the electrolyte interface before recombining with conduction band electrons. This allows for water oxidation by the valence band holes even though their diffusion length is only a few nanometers. Distances are longer in the particles produced by SP favoring recombination of photoinduced charge carriers. Open-circuit photovoltage measurements indicate a lower surface state density for the nanoplatelets as compared to the round particles. These factors explain the much higher photoactivity of the USP compared to the SP deposited alpha-Fe(2)O(3) layers. Addition of hydrogen peroxide to the alkaline electrolyte further improves the photocurrent-voltage characteristics of films generated by USP indicating the hole transfer from the valence band of the semiconductor oxide to the adsorbed water to be the rate-limiting kinetic step in the oxygen generation reaction. PMID:16853192

Duret, Alexis; Grätzel, Michael

2005-09-15

170

Observation of Nanospherical n-SnO2/p-Si Heterojunction Fabricated by Ultrasonic Spray Pyrolysis Technique  

NASA Astrophysics Data System (ADS)

Thin film of tin oxide (SnO2) was prepared on p-type polished silicon wafer by ultrasonic spray pyrolysis technique using SnCl4 precursor solution to fabricate nanospherical n-SnO2/p-Si heterojunction photoelectric device. Deposition of film was achieved at 400°C substrate temperature. The self-made ultrasonic spray pyrolysis system is very cheap and convenient. The microstructural, optical and electrical properties of the SnO2 film were characterized by XRD, SEM, XPS, UV-VIS spectrophotometer, four point probe and Hall effect measurement, respectively. The SnO2 film has the nanospherical particles. The electrical properties of heterojunction were investigated by I-V measurement, which reveals that the heterojunction shows strong rectifying behavior under a dark condition. The ideality factor and the saturation current density of this diode are 4.27 and 2.52 × 10-6 A/cm2, respectively. And the values of IF/IR (IF and IR stand for forward and reverse current, respectively) at 5 V is found to be as high as 248. The SnO2/p-Si heterojunction device exhibits obvious photovoltaic effect. Under an AM1.5 illumination condition, the open-circuit voltage (Voc), short-circuit current density (JSC), fill factor (FF) of the device are 150 mV, 3.9 × 10-3 mA/cm2 and 20.58%, respectively. High photocurrent is obtained under a reverse bias when the crystalline quality of SnO2 film is good enough to transmit the light into p-Si. Under 6.3 mW/cm2 illumination, when the reverse bias is -5 V, the photocurrent gain is as high as 86.

He, Bo; Xu, Jing; Xing, Huaizhong; Wang, Chunrui; Guo, Ying; Lu, Hongwei

2013-10-01

171

Synthesis and characterization of earth abundant and nontoxic metal chalcogenides produced via aerosol spray pyrolysis for photovoltaic applications  

NASA Astrophysics Data System (ADS)

A novel synthesis technique for the production of copper zinc tin sulfide (CZTS) nanocrystals has been developed using aerosol spray pyrolysis. CZTS is a quaternary semiconducting material that shows promise as a replacement to common semiconductors such as CdTe and CIGS for use in photovoltaic devices. CIGS is currently being commercialized in the photovoltaic industry, but rare and expensive indium and gallium components threaten its long term viability. CZTS looks to be one of the best alternatives to CIGS with all earth abundant and non-toxic materials and recent impressive gains in efficiency. A number of synthesis techniques have been thoroughly studied and detailed previously. In our novel approach, we synthesis single phase nanocrystals, starting with zinc, copper, and tin diethyldithiocarbamate precursors in a toluene solvent. The precursor solution is aerosolized using an ultrasonic nebulizer wherein the droplets are vacuumed through a tube furnace and nucleation occurs. We reproducibly synthesize kesterite, Cu2ZnSnS4, nanocrystals. This technique continuously converts the chemical precursor into high-purity nanopowder with a production rate of ~50 mg/hour for an un-optimized, lab-scale reactor. Using the same precursor chemistry, we have also been able to deposit high-quality CZTS thin films directly onto Mo-coated Swiss glass substrates using the aerosol spray pyrolysis technique. A thorough discussion of the current photovoltaic field, the processing parameters and challenges of nanocrystal and thin film production, and the experimental results will be presented. Characterization via Raman spectroscopy, EDS, XRD, TEM and XPS will be offered along with future recommendations and considerations.

Davis, Patrick John

172

The characteristic and evaluation method of fast pyrolysis of microalgae to produce syngas.  

PubMed

The fast pyrolysis of Chlorella vulgaris was carried out in a quartz tube reactor under different pyrolysis temperature levels. The product fractional yields, gaseous products and the evaluation method based on heating value and energy consumption were analyzed in order to obtain the optimal condition to produce syngas. The results indicated that the higher the pyrolysis temperature level was, the higher the bio-fuel yield was. 900°C is the best temperature to obtain the maximum bio-fuel yield (91.09 wt.%). And the highest emission of CO and H2 were achieved under the pyrolysis temperature of 800 and 900°C, respectively. According to the evaluation method based on heating value and energy consumption, there was a significant impact on the syngas production under different pyrolysis temperatures. Furthermore, the evaluation method based on energy consumption indicated that 800°C was the optimal pyrolysis temperature to produce syngas. PMID:23693148

Hu, Zhifeng; Ma, Xiaoqian; Li, Longjun

2013-07-01

173

Indium doped zinc oxide thin films deposited by ultrasonic spray pyrolysis technique: Effect of the substrate temperature on the physical properties  

Microsoft Academic Search

Indium doped zinc oxide (ZnO:In) thin solid films were deposited on soda-lime glass substrates by the ultrasonic spray pyrolysis technique. The effect of the substrate temperature on the electrical, morphology, and optical characteristics of ZnO:In thin films was studied. It was found that, as the substrate temperature increases, the electrical resistivity decreases, reaching a minimum value in the order of

L. Castañeda; A. Maldonado; A. Escobedo-Morales; M. Avendaño-Alejo; H. Gómez; J. Vega-Pérez; M. de la L. Olvera

2011-01-01

174

Mixed-metal oxide nanopowders by liquid-feed flame spray pyrolysis (LF-FSP): Synthesis and processing of core-shell nanoparticles  

Microsoft Academic Search

In this dissertation, liquid feed--flame spray pyrolysis (LF-FSP) was used for the synthesis and characterization of mixed-metal oxide nanopowders in the Ce-Zr-Al-O system for potential catalytic, photonic, electronic and structural applications. The LF-FSP process aerosolizes metalloorganic precursors dissolved in an alcohol solvent with oxygen, combusts the aerosol, and then rapidly quenches the gaseous species to produce nanosize oxide \\

Min Kim

2008-01-01

175

Porous TiO 2 thin films synthesized by a spray pyrolysis deposition (SPD) technique and their application to dye-sensitized solar cells  

Microsoft Academic Search

Titanium dioxide (TiO2) thin films were synthesized on glass substrates from titanium(IV)oxy acetylacetonate 2-butanol solution by a spray pyrolysis deposition (SPD) technique. The films consisted of TiO2 leaflets and showed the oriented growth along the (200) direction. The surface area of the film was successfully increased by adding a small amount of aluminum(III) acetylacetonate (AA) in the source solution. This

Masayuki Okuya; Koji Nakade; Shoji Kaneko

2002-01-01

176

Temperature Effect on the Synthesis of Multi-Walled Carbon Nanotubes by Spray Pyrolysis of Botanical Carbon Feedstocks: Turpentine, ?-pinene and ?-pinene  

Microsoft Academic Search

The chemistry of the different components of turpentine and the effect of temperature on the synthesis of multi-walled carbon nanotubes (MWCNTs) by spray pyrolysis using ferrocene as catalyst in a temperature range of 700–1000°C at 100°C intervals was investigated. Turpentine with high ?-pinene concentration (83.4%) and low ?-pinene concentration (8.22%), as well as pure ?-pinene and ?-pinene, were used as

J. Lara-Romero; J. C. Calva-Yañez; J. López-Tinoco; G. Alonso-Nuñez; S. Jiménez-Sandoval

2011-01-01

177

Spray pyrolysis synthesis of nanostructured LiFe x Mn 2? x O 4 cathode materials for lithium-ion batteries  

Microsoft Academic Search

A series of partially Fe-substituted lithium manganese oxides LiFexMn2?xO4 (0?x?0.3) was successfully synthesized by an ultrasonic spray pyrolysis technique. The resulting powders were spherical nanostructured particles which comprised the primary particles with a few tens of nanometer in size, while the morphology changed from spherical and porous to spherical and dense with increasing Fe substitution. The densification of particles progressed

Izumi Taniguchi; Zhumabay Bakenov

2005-01-01

178

Aluminum oxide thin films deposited on silicon substrates from Al(NO3)3 and an organic solvent by spray pyrolysis  

Microsoft Academic Search

Aluminum oxide thin films were deposited on silicon substrates at temperatures in the range from 500 to 650 °C, from Al(NO3)3 dissolved in N,N-Dimethylformamide and using the spray pyrolysis technique. The films of aluminum oxide resulted stoichiometric, amorphous and optically transparent in the visible spectrum, with a refractive index close to 1.66 when a 0.2 molar solution of Al(NO3)3 was

M. Aguilar-Frutis; J. Guzmán-Mendoza; T. Alejos; M. García-Hipólito; C. Falcony

2003-01-01

179

Structural characterization of cadmium oxide thin films deposited by spray pyrolysis  

Microsoft Academic Search

A series of CdO thin films have been prepared by spray pyrolytic technique at different substrate temperatures. X-ray diffraction scans confirmed the polycrystalline structure of the films. The films exhibit preferential orientation along the (111) plane. To describe the preferential orientation, the texture coefficient has been calculated and the standard deviation factor has also been evaluated to explain the growth

K. Gurumurugan; D. Mangalaraj; Sa. K. Narayandass

1995-01-01

180

Chemical composition and temperature dependent performance of ZnO-thin film transistors deposited by pulsed and continuous spray pyrolysis  

NASA Astrophysics Data System (ADS)

Zinc oxide thin film transistors (TFTs) deposited by continuous and pulsed spray pyrolysis were investigated to analyze process kinetics which make reduction of process temperature possible. Thus, fluid mechanics, chemical composition, electrical performance, and deposition and annealing temperature were systematically analyzed. It was found that ZnO layers continuously deposited at 360 °C contained zinc oxynitrides, CO3, and hydro carbonate groups from pyrolysis of basic zinc acetate. Statistically, every second wurtzite ZnO unit cell contained an impurity atom. The purity and performance of the ZnO-TFTs increased systematically with increasing deposition temperature due to an improved oxidation processes. At 500 °C the zinc to oxygen ratio exceeded a high value of 0.96. Additionally, the ZnO film was not found to be in a stabilized state after deposition even at high temperatures. Introducing additional subsequent annealing steps stabilizes the film and allows the reduction of the overall thermal stress to the substrate. Further improvement of device characteristics was obtained by pulsed deposition which allowed a more effective transport of the by-products and oxygen. A significant reduction of the deposition temperature by 140 °C was achieved compared to the same performance as in continuous deposition mode. The trap density close to the Fermi energy could be reduced by a factor of two to 4 × 1017 eV-1 cm-3 due to the optimized combustion process on the surface. The optimization of the deposition processes made the fabrication of TFTs with excellent performance possible. The mobility was high and exceeded 12 cm2/V s, the subthreshold slope was 0.3 V dec-1, and an on-set close to the ideal value of 0 V was achieved.

Ortel, Marlis; Balster, Torsten; Wagner, Veit

2013-12-01

181

The effect of solution concentration on the physical and electrochemical properties of vanadium oxide films deposited by spray pyrolysis  

NASA Astrophysics Data System (ADS)

Vanadium oxide thin films were prepared on glass substrates by using the spray pyrolysis technique. The effect of solution concentration (0.1 M, 0.2 M and 0.3 M) on the nanostructural, electrical, optical, and electrochromic properties of deposited films were investigated using X-ray diffraction, scanning electron microscopy, UV—vis spectroscopy, and cyclic volta-metrics. The X-ray diffraction shows that only the sample at 0.1 M has a single ?-V2O5 phase and the others have mixed phases of vanadium oxide. The lowest sheet resistance was obtained for the samples prepared at 0.3 M solution. It was also found that the optical transparency of the samples changes from 70% to 35% and the optical band gap of the samples was in the range of 2.20 to 2.41 eV, depending on the morality of solution. The cycle voltammogram shows that the sample prepared at 0.3 M has one-step electerochoromic but the other samples have two-step electerochoromic. The results show a correlation between the cycle voltammogram and the physical properties of the films.

Mousavi, M.; Kompany, A.; Shahtahmasebi, N.; Bagheri-Mohagheghi, M. M.

2013-10-01

182

Spray pyrolysis derived ZnMgO:In thin films: Investigation of the structural, optical and electrical properties  

NASA Astrophysics Data System (ADS)

Zn1-xMgxO:In films were deposited on quartz substrates via ultrasonic spray pyrolysis (USP). By tuning the molar ratio of Zn and Mg sources, the tunable band gap in ZnMgO:In films were realized. The obtained films exhibited wurtzite crystal structure with a preferential c-axis orientation. Larger grain size was obtained with increasing the Mg introduction. Photoluminescence (PL) indicated that the peaks of near-band-edge (NBE) emission appeared as a blue-shift from 378 nm to 370 nm, labeled as x value increase from 0 to 0.15. Optical band gap (Eg) calculated from the absorption edge further confirmed the blue-shift phenomenon due to the Mg substitution for Zn lattice sites. The average transmittance was about 90% in the visible wavelength region (400-800 nm). The increasing resistivity from 6.70 × 10-3 ? cm to 2.14 × 10-2 ? cm and decreasing mobility from 24.7 cm2 V-1 S-1 to 6.46 cm2 V-1 S-1 were observed.

Yan, Wei; Tan, Jin; Zhang, Wei; Liang, Yujun; Feng, Shan; Lei, Xinrong; Wang, Hongquan

2013-08-01

183

Effect of S-doping on structural, optical and electrochemical properties of vanadium oxide thin films prepared by spray pyrolysis  

NASA Astrophysics Data System (ADS)

In this research, S-doped vanadium oxide thin films, with doping levels from 0 to 40 at.%, are prepared by spray pyrolysis technique on glass substrates. For electrochemical measurements, the films were deposited on florin-tin oxide coated glass substrates. The effect of S-doping on structural, electrical, optical and electrochemical properties of vanadium oxide thin films was studied. The x-ray diffractometer analysis indicated that most of the samples have cubic ?-V2O5 phase structure with preferred orientation along [200]. With increase in the doping levels, the structure of the samples tends to be amorphous. The scanning electron microscopy images show that the structure of the samples is nanobelt-shaped and the width of the nanobelts decreases from nearly 100 to 40 nm with increase in the S concentration. With increase in the S-doping level, the sheet resistance and the optical band gap increase from 940 to 4015 k?/square and 2.41 to 2.7 eV, respectively. The cyclic voltammogram results obtained for different samples show that the undoped sample is expanded and the sample prepared at 20 at.% S-doping level has sharper anodic and cathodic peaks.

Mousavi, M.; Kompany, A.; Shahtahmasebi, N.; Bagheri-Mohagheghi, M.-M.

2013-12-01

184

Investigations on structural, vibrational, morphological and optical properties of CdS and CdS/Co films by ultrasonic spray pyrolysis  

NASA Astrophysics Data System (ADS)

CdS and CdS/Co films have been deposited on glass substrates by an ultrasonic spray pyrolysis method. The effects of Co incorporation on the structural, optical, morphological, elemental and vibrational properties of these films were investigated. XRD analysis confirmed the hexagonal wurtzite structure of all films and had no impurity phase. While CdS film has (0 0 2) as the preferred orientation, CdS/Co films have (1 1 0) as the preferred orientation. The direct optical band gap was found to decrease from 2.42 to 2.39 eV by Co incorporation. The decrease of the direct energy gaps by increasing Co contents is mainly due to the sp-d exchange interaction between the localized d-electrons of Co 2+ ions and band electrons of CdS. After the optical investigations, it was seen that the transmittance of CdS films decreased by Co content. The Raman measurements revealed two peaks corresponding to the 1LO and 2LO modes of hexagonal CdS. The vibrational modes of Cd-S were obtained in the wavenumber range (590-715 cm -1) using Fourier transform infrared spectroscopy (FTIR). The elemental analysis of the film was done by energy dispersive X-ray spectrometry.

Aksay, S.; Polat, M.; Özer, T.; Köse, S.; Gürbüz, G.

2011-09-01

185

Effect of variation of tin concentration on the properties of Cu2ZnSnS4 thin films deposited using chemical spray pyrolysis  

NASA Astrophysics Data System (ADS)

Cu2ZnSnS4 (CZTS) thin films were prepared using chemical spray pyrolysis technique on soda lime glass (SLG) substrates. The effect of tin concentration on the structural, optical and electrical properties was investigated. We deposited films by varying tin concentration from 0.007 M to 0.013 M in steps of 0.0015 M keeping the concentration of copper, zinc and sulphur at 0.02 M, 0.01 M and 0.12 M respectively. It was found that crystallinity of the film increased up to the tin concentration of 0.01 M and then decreases. Band gap of the films steadily decreased from 1.48 to 1.26 eV with increase in tin concentration. All the samples were observed to be p-type by hot probe method. Resistivity of the films increased with increase in tin concentration. In this work we tuned the optoelectronic properties by varying the tin concentration alone and optimized the concentration of tin which yields samples ideal for photovoltaic applications.

Rajeshmon, V. G.; Kuriakose, Abin; Kartha, C. Sudha; Vijayakumar, K. P.

2013-02-01

186

Highly photoconducting O2-doped CdS films deposited by spray pyrolysis  

NASA Technical Reports Server (NTRS)

CdS films have been prepared by spraying in air solutions of thiourea with either cadmium chloride or cadmium acetate with varying mole ratio and substrate temperature, and subsequently heat treating in oxygen. Substrates included both bare glass or sapphire and transparent conducting oxide-coated sapphire for electrical measurements lateral and transverse to the CdS plane, respectively. Dark resistances of over 10 to the 14th ohms and light-to-dark conductivities of up to 10 to the 7th were obtained using uncoated substrates. The use of Cd(C2H3O2)2 in place of CdCl2 greatly increased the speed of response although with some sacrifice in photoconductivity. Deposition of CdS on ITO-coated surfaces led to greatly reduced dark resistances for the case of CdCl2, but not Cd(C2H3O2)2, presumably due to HCl reaction with the ITO coating in the course of spraying with the former. Ion microprobe analysis detected indium within the CdS films exhibiting low dark resistance. Measurements of the dark and light conductivities at temperatures down to 77 K are given as are the response times for unetched and HCl-etched surfaces.

Richards, D.; El-Korashy, A. M.; Stirn, R. J.; Karulkar, P. C.

1984-01-01

187

A New Method for Spray Coloring Silicone Elastomer.  

National Technical Information Service (NTIS)

A new method has been developed for coloring extraoral maxillofacial prostheses prepared from silicone elastomer RTV 399. In this method, the RTV elastomer prosthesis, containing pigments which impart a basic shade to the elastomer, is sprayed using an ar...

J. E. Ouellette

1968-01-01

188

UV and VUV characteristics of (YGd){sub 2}O{sub 3}:Eu phosphor particles prepared by spray pyrolysis from polymeric precursors  

SciTech Connect

Red-emitting (YGd){sub 2}O{sub 3}:Eu phosphor particles, with high luminescence efficiency under vacuum ultraviolet (VUV) and ultraviolet (UV) excitation, were prepared by a large-scale spray pyrolysis process. To control the morphology of phosphor particles under severe preparation conditions, spray solution with polymeric precursors were introduced in spray pyrolysis. The prepared (YGd){sub 2}O{sub 3}:Eu phosphor particles had spherical shape and filled morphology even after post-treatment irrespective of Gd/Y ratio. In the case of solution with polymeric precursors, long polymeric chains formed by esterification reaction in a hot tubular reactor; the droplets turned into viscous gel, which retarded the precipitation of nitrate salts and promoted the volume precipitation of droplets. The brightness of (YGd){sub 2}O{sub 3}:Eu phosphor particles increased with increasing gadolinium content, and the Gd{sub 2}O{sub 3}:Eu phosphor had the highest luminescence intensity under UV and VUV excitation. The maximum peak intensity of Gd{sub 2}O{sub 3}:Eu phosphor particles under UV and VUV were 118 and 110% of the commercial Y{sub 2}O{sub 3}:Eu phosphor particles, respectively.

Kim, E.J.; Kang, Y.C.; Park, H.D.; Ryu, S.K

2003-02-20

189

A new high ultraviolet sensitivity FTO-GaP Schottky photodiode fabricated by spray pyrolysis  

NASA Astrophysics Data System (ADS)

A new high quantum efficiency gallium phosphide Schottky photodiode has been developed by spray deposition of heavily doped tin oxide films on n-type epitaxial structures, as an alternative to the conventional Schottky photodiodes using a semitransparent gold electrode. It is shown that fluorine-doped tin oxide films are more effective as transparent electrodes than tin-doped indium oxide films. The proposed photodiodes have a typical responsivity near 0268-1242/13/1/016/img9 at 440 nm and an unbiased internal quantum efficiency close to 100%, in the range from 250 to 450 nm. The model used to calculate the internal quantum efficiency (based on the optical constants of tin oxide films and gallium phosphide epitaxial layers) is found to be in good agreement with the experimental results. The data show that the quantum efficiency is strongly dependent on the thickness of the transparent electrode, owing to optical interference effects. The noise equivalent power for 440 nm is 0268-1242/13/1/016/img10, which indicates that these photodiodes can be used for accurate measurements in the short-wavelength range, even in the presence of stronger infrared background radiation.

Malik, Alexander; Sêco, Ana; Fortunato, Elvira; Martins, Rodrigo; Shabashkevich, Boris; Piroszenko, Sergei

1998-01-01

190

Influences of alcoholic solvents on spray pyrolysis deposition of TiO{sub 2} blocking layer films for solid-state dye-sensitized solar cells  

SciTech Connect

Influences of alcoholic solvents for titanium diisopropoxide bis(acetylacetonate) (TPA) precursor solutions on the spray pyrolysis deposited TiO{sub 2} films and the photovoltaic performance of the solid-state dye-sensitized solar cells (SDSCs) using these TiO{sub 2} films as the blocking layers were investigated. Smooth TiO{sub 2} films were obtained by spray pyrolysis deposition of a TPA solution in isopropanol (IPA) at a relatively low temperature of 260 Degree-Sign C. On the other hand, when ethanol was used as solvent, the TiO{sub 2} films fabricated at the same temperature showed much rougher surfaces with many pinholes. Our results showed that ethanol reacts with TPA to form titanium diethoxide bis(acetylacetonate) (TEA), which requires a higher thermal decomposition temperature than that of TPA. SDSCs with TiO{sub 2} blocking layer films fabricated using a TPA solution in IPA showed higher power conversion efficiencies with smaller variations. - Graphical abstract: Alcoholic solvents used for the TiO{sub 2} precursor play a critical role in determining the surface morphology of blocking layers and thus the photovoltaic performance of the SDSCs. Highlights: Black-Right-Pointing-Pointer Solvent influences morphology of spray pyrolysis deposited TiO{sub 2} blocking layer. Black-Right-Pointing-Pointer Ethanol reacts with TPA, resulting poor quality of blocking layer. Black-Right-Pointing-Pointer Isopropanol is better than ethanol for obtaining smooth blocking layer. Black-Right-Pointing-Pointer SDSC with blocking layer made with isopropanol showed better performance.

Jiang, Changyun, E-mail: jiangc@imre.a-star.edu.sg [Institute of Materials Research and Engineering, A-STAR, 3 Research Link, 117602 Singapore (Singapore)] [Institute of Materials Research and Engineering, A-STAR, 3 Research Link, 117602 Singapore (Singapore); Koh, Wei Lin; Leung, Man Yin [Institute of Materials Research and Engineering, A-STAR, 3 Research Link, 117602 Singapore (Singapore)] [Institute of Materials Research and Engineering, A-STAR, 3 Research Link, 117602 Singapore (Singapore); Hong, Wei [Department of Chemical Engineering and Waterloo Institute for Nanotechnology (WIN), University of Waterloo, 200 University Ave West ON, Waterloo, Canada N2L 3G1 (Canada)] [Department of Chemical Engineering and Waterloo Institute for Nanotechnology (WIN), University of Waterloo, 200 University Ave West ON, Waterloo, Canada N2L 3G1 (Canada); Li, Yuning, E-mail: yuning.li@uwaterloo.ca [Institute of Materials Research and Engineering, A-STAR, 3 Research Link, 117602 Singapore (Singapore) [Institute of Materials Research and Engineering, A-STAR, 3 Research Link, 117602 Singapore (Singapore); Department of Chemical Engineering and Waterloo Institute for Nanotechnology (WIN), University of Waterloo, 200 University Ave West ON, Waterloo, Canada N2L 3G1 (Canada); Zhang, Jie [Institute of Materials Research and Engineering, A-STAR, 3 Research Link, 117602 Singapore (Singapore)] [Institute of Materials Research and Engineering, A-STAR, 3 Research Link, 117602 Singapore (Singapore)

2013-02-15

191

Spray pyrolysis deposition of polycrystalline magnesia films and their use as buffer layers in Bi(Pb)-Sr-Ca-Cu-O\\/MgO\\/Al 2O 3 (or glass ceramics) structures  

Microsoft Academic Search

The deposition of MgO films on Al2O3 and glass ceramic substrates by spray pyrolysis of a water-ethanol magnesium nitrate precursor solution has been studied. Dense polycrystalline films have been obtained by repeated pyrolysis at 300–350 °C followed by annealing of the deposit in air at 970 °C. It has been established that the finest grains obtained under these experimental conditions

I. Stambolova; K. Konstantinov; D. Kovacheva; M. Khristov; P. Peshev; T. Donchev

1997-01-01

192

Electrochemical properties of LiFe 0.9Mg 0.1PO 4 \\/ carbon cathode materials prepared by ultrasonic spray pyrolysis  

Microsoft Academic Search

The LiFe0.9Mg0.1PO4\\/C powder of pure olivine phase can be prepared with the duplex process of spray pyrolysis synthesis (at 450 ?C) and subsequent heat treatment (at 700 ?C for 2, 4 and 8 h). From scanning electron microscopy observation with corresponding elemental mapping images of iron, phosphorous and magnesium, it could be found that the LiFe0.9Mg0.1PO4 powders are covered with fine pyrolyzed carbon.

Tsung-Hsien Teng; Mu-Rong Yang; She-Hung Wu; Yi-Ping Chiang

2007-01-01

193

Synthesis and characterization of Y 3Al 5O 12 and ZrO 2–Y 2O 3 thermal barrier coatings by combustion spray pyrolysis  

Microsoft Academic Search

Y3Al5O12 and ZrO2–Y2O3 (8 mol% YSZ) coatings for potential application as thermal barrier coatings were prepared by combustion spray pyrolysis. Thermal cycling of as deposited coatings on stainless steel and FeCrAlY bond coat substrates was carried out at 1000 °C and 1200 °C to determine the thermal fatigue response. Structural and morphological studies on Y3Al5O12 and 8 mol% YSZ coatings before and after thermal

S. Saravanan; G. Hari Srinivas; V. Jayaram; M. Paulraj; S. Asokan

2008-01-01

194

Influence of Boron doping on the structural, optical and electrical properties of CdO thin films by spray pyrolysis technique  

NASA Astrophysics Data System (ADS)

Cadmium oxide and Boron (B) doped Cadmium oxide thin films were deposited using spray pyrolysis technique. The structural, morphological, electrical and optical properties of undoped and B doped CdO films are analyzed by varying the dopant concentration in the solution. The structural study shows the polycrystalline nature and cubic structure of undoped and B doped CdO thin films. Surface morphological study reveals that the grains are spherical in shape. Optical and electrical studies showed n-type semiconducting nature and optical band gap of 2.44 eV of deposited thin films.

Velusamy, P.; Babu, R. Ramesh; Ramamurthi, K.

2014-04-01

195

Facile synthesis of antimony-doped tin oxide nanoparticles by a polymer-pyrolysis method  

Microsoft Academic Search

In this article, antimony-doped tin oxide (ATO) nanoparticles was synthesized by a facile polymer-pyrolysis method. The pyrolysis behaviors of the polymer precursors prepared via in situ polymerization of metal salts and acrylic acid were analyzed by simultaneous thermogravimetric and differential scanning calorimetry (TG–DSC). The structural and morphological characteristics of the products were studied by powder X-ray diffraction (XRD) and transmission

Yuan-Qing Li; Jian-Lei Wang; Shao-Yun Fu; Shi-Gang Mei; Jian-Min Zhang; Kang Yong

2010-01-01

196

Method and apparatus for spraying molten materials  

DOEpatents

A metal spray apparatus is provided with a supersonic nozzle. Molten metal is injected into a gas stream flowing through the nozzle under pressure. By varying the pressure of the injected metal, the droplet can be made in various selected sizes with each selected size having a high degree of size uniformity. A unique one piece graphite heater provides easily controlled uniformity of temperature in the nozzle and an attached tundish which holds the pressurized molten metal. A unique U-shaped gas heater provides extremely hot inlet gas temperatures to the nozzle. A particularly useful application of the spray apparatus is coating of threads of a fastener with a shape memory alloy. This permits a fastener to be easily inserted and removed but provides for a secure locking of the fastener in high temperature environments. 12 figs.

Glovan, R.J.; Tierney, J.C.; McLean, L.L.; Johnson, L.L.; Nelson, G.L.; Lee, Y.M.

1996-06-25

197

Effects of In-situ and Ex-situ Heat-Treatment Procedures on the Transport Properties of the MgB 2 Superconducting Thin Films Fabricated by Ultrasonic Spray Pyrolysis (USP) System  

Microsoft Academic Search

Superconducting MgB2 thin films have been prepared using Ultrasonic Spray Pyrolysis (USP) system. 2.4 MHz USP system and various solutions which\\u000a contain different Mg, B and de-ionized water and LAPSA concentrations and gas atmospheres were used to obtain 500 nm to 1.0\\u000a ?m thick MgB2 films. Some of the films produced were heat treated in-situ in the spraying chamber during deposition

M. E. Yakinci; Y. Aydogdu; M. A. Aksan; Y. Balci; S. Altin

2011-01-01

198

Effect of different dopant elements (Al, Mg and Ni) on microstructural, optical and electrochemical properties of ZnO thin films deposited by spray pyrolysis (SP)  

NASA Astrophysics Data System (ADS)

In the present work we studied the influence of the dopant elements and concentration on the microstructural and electrochemical properties of ZnO thin films deposited by spray pyrolysis. Transparent conductive thin films of zinc oxide (ZnO) were prepared by the spray pyrolysis process using an aqueous solution of zinc acetate dehydrate [Zn(CH3COO)2·2H2O] on soda glass substrate heated at 400 ± 5 °C. AlCl3, MgCl2 and NiCl2 were used as dopant. The effect of doping percentage (2-4%) has been investigated. Afterwards the samples were thermally annealed in an ambient air during one hour at 500 °C. X-ray diffraction showed that films have a wurtzite structure with a preferential orientation along the (0 0 2) direction for doped ZnO. The lattice parameters a and c are estimated to be 3.24 and 5.20 ?, respectively. Transmission allowed to estimate the band gaps of ZnO layers. The electrochemical studies revealed that the corrosion resistance of the films depended on the concentration of dopants.

Benzarouk, Hayet; Drici, Abdelaziz; Mekhnache, Mounira; Amara, Abdelaziz; Guerioune, Mouhamed; Bernède, Jean Christian; Bendjffal, Hacen

2012-09-01

199

The TAB method for numerical calculation of spray droplet breakup  

SciTech Connect

A short history is given of the major milestones in the development of the stochastic particle method for calculating liquid fuel sprays. The most recent advance has been the discovery of the importance of drop breakup in engine sprays. We present a new method, called the TAB method, for calculating drop breakup. Some theoretical properties of the method are derived; its numerical implementation in the computer program KIVA is described; and comparisons are presented between TAB-method calculations and experiments and calculations using another breakup model.

O'Rourke, P.J.; Amsden, A.A.

1987-01-01

200

The TAB method for numerical calculation of spray droplet breakup  

NASA Astrophysics Data System (ADS)

A short history is given of the major milestones in the development of the stochastic particle method for calculating liquid fuel sprays. The most recent advance has been the discovery of the importance of drop breakup in engine sprays. A new method, called TAB, for calculating drop breakup is presented. Some theoretical properties of the method are derived; its numerical implementation in the computer program KIVA is described; and comparisons are presented between TAB-method calculations and experiments and calculations using another breakup model.

Orourke, P. J.; Amsden, A. A.

201

Synthesis and hyperthermia property of hydroxyapatite-ferrite hybrid particles by ultrasonic spray pyrolysis  

NASA Astrophysics Data System (ADS)

Biocompatible hybrid particles composed of hydroxyapatite (Ca 10(PO 4) 6(OH) 2, HAp) and ferrite (?-Fe 2O 3 and Fe 3O 4) were synthesized using a two-step procedure. First, the ferrite particles were synthesized by co-precipitation. Second, the suspension, which was composed of ferrite particles by a co-precipitation method, Ca(NO 3) 2, and H 3PO 4 aqueous solution with surfactant, was nebulized into mist ultrasonically. Then the mist was pyrolyzed at 1000 °C to synthesize HAp-ferrite hybrid particles. The molar ratio of Fe ion and HAp was (Fe 2+ and Fe 3+)/HAp=6. The synthesized hybrid particle was round and dimpled, and the average diameter of a secondary particle was 740 nm. The cross section of the synthesized hybrid particles revealed two phases: HAp and ferrite. The ferrite was coated with HAp. The synthesized hybrid particles show a saturation magnetization of 11.8 emu/g. The net saturation magnetization of the ferrite component was calculated as 32.5 emu/g. The temperature increase in the AC-magnetic field (370 kHz, 1.77 kA/m) was 9 °C with 3.4 g (the ferrite component was 1.0 g). These results show that synthesized hybrid particles are biocompatible and might be useful for magnetic transport and hyperthermia studies.

Inukai, Akihiro; Sakamoto, Naonori; Aono, Hiromichi; Sakurai, Osamu; Shinozaki, Kazuo; Suzuki, Hisao; Wakiya, Naoki

2011-04-01

202

Method of producing pyrolysis gases from carbon-containing materials  

DOEpatents

A gasification process of improved efficiency is disclosed. A dual bed reactor system is used in which carbon-containing feedstock materials are first treated in a gasification reactor to form pyrolysis gases. The pyrolysis gases are then directed into a catalytic reactor for the destruction of residual tars/oils in the gases. Temperatures are maintained within the catalytic reactor at a level sufficient to crack the tars/oils in the gases, while avoiding thermal breakdown of the catalysts. In order to minimize problems associated with the deposition of carbon-containing materials on the catalysts during cracking, a gaseous oxidizing agent preferably consisting of air, oxygen, steam, and/or mixtures thereof is introduced into the catalytic reactor at a high flow rate in a direction perpendicular to the longitudinal axis of the reactor. This oxidizes any carbon deposits on the catalysts, which would normally cause catalyst deactivation.

Mudge, Lyle K. (Richland, WA); Brown, Michael D. (West Richland, WA); Wilcox, Wayne A. (Kennewick, WA); Baker, Eddie G. (Richland, WA)

1989-01-01

203

Effect of Boric Acid Flux and Drying Control Chemical Additive on the Characteristics of Y2O3:Eu Phosphor Particles Prepared by Spray Pyrolysis  

NASA Astrophysics Data System (ADS)

Y2O3:Eu phosphor particles with a spherical shape, a fine size, and high brightness under vacuum ultraviolet (VUV) illumination were prepared by spray pyrolysis. The polymeric precursors were needed to modify the spray solution to prepare spherical particles. The use of only flux with the polymeric precursors did not produce dense and spherical Y2O3:Eu particles; that is, the produced particles were very porous. The addition of both a drying control chemical additive (DCCA) and boric acid to a spray solution containing polymeric precursors was found to produce Y2O3:Eu phosphor particles with a dense structure while maintaining the spherical morphology. According to X-ray diffraction (XRD) analysis, the DCCA induced an enhancement of crystallinity. The use of boric acid flux improved the photoluminescence (PL) intensity under VUV illumination. In addition, the use of both boric acid flux and a DCCA with polymeric precursors further improved the PL intensity owing to the enhancement of the morphology and the crystallinity.

Koo, Hye Young; Ju, Seo Hee; Hong, Seung Kwon; Jung, Dae Soo; Kang, Yun Chan; Jung, Kyeong Youl

2006-12-01

204

Mercury analysis of various types of coal using acid extraction and pyrolysis methods  

SciTech Connect

The mercury contents of various types of coal currently consumed in Korea were analyzed using acid extraction and pyrolysis methods. The results of analysis by acid extraction and pyrolysis methods were compared and discussed. Generally, high mercury concentrations of 105.6 to 434.5 ng/g (by acid extraction) and 125.7 to 475.4 ng/g (by pyrolysis) were obtained for tested anthracite coals in this study. For bituminous coals, the mercury contents were 11.5-48 ng/g (by acid extraction) and 12.5-52.4 ng/g (by pyrolysis). For coal samples, much simpler and far less time-consuming pyrolysis method tends to give higher values for the Hg concentration than the acid extraction method (by less than 10%) because of the interference from a UV absorption by SOx generated during thermal destruction of coal matrix. Also, further analysis shows that coals with higher densities have higher mercury contents and that the sulfur and mercury contents of coals are positively correlated with each other. 10 refs., 4 figs., 2 tabs.

Jae Young Park; Jong Hyun Won; Tai Gyu Lee [Yonsei University, Seoul (Republic of Korea). Department of Chemical Engineering

2006-12-15

205

Influence of impregnation method on metal retention of CCB-treated wood in slow pyrolysis process.  

PubMed

In the present work, the effects of copper, chromium and boron on the pyrolysis of wood and their distribution in the pyrolysis products were investigated. For this, the wood has been impregnated with chromium-copper-boron (CCB). In addition, to describe the effects of impregnation method, vacuum-pressure and dipping methods were also conducted. Thermogravimetric analysis (TGA) results show that an increase in the final residue and decrease in degradation temperature on both methods of treated wood compared to untreated wood. Then, slow pyrolysis experiments were carried out in a laboratory reactor. The mass balance of pyrolysis products is confirmed by TGA. Furthermore, the concentration of metals in the final residue is measured by inductively coupled plasma mass spectroscopy (ICP-MS). The results show that the final residue contains more than 45% of the initial amount of metal present in the treated wood. The phenomenon is more pronounced with vacuum-pressure treated wood. The heating values of pyrolysis products were analyzed. The heating value of charcoal obtained from treated and untreated wood is approximately same. But the heating value of tar from untreated wood is higher than the heating value of the tar from treated wood. PMID:22835770

Kinata, Silao Espérance; Loubar, Khaled; Bouslamti, Amine; Belloncle, Christophe; Tazerout, Mohand

2012-09-30

206

Crystalline phase reduction of cuprous oxide (Cu2O) nanoparticles accompanied by a morphology change during ethanol-assisted spray pyrolysis.  

PubMed

Metallic copper nanoparticles are produced by spray pyrolysis of copper nitrates with an addition of ethanol as cosolvent at 600 degrees C. Depending on the synthesis temperature, two interesting reaction pathways are found: below 525 degrees C, approximately 10% of hollow Cu(2)O parent particles are oxidized to CuO and then reduced to Cu, but at higher temperature, the remaining Cu(2)O takes a direct path to Cu, accompanied by a morphology change. These interesting reaction regimes are discussed in the aspects of phase-transformation kinetics, gas-phase and solid-phase thermodynamics, force balance, and their possible influences on structural instability. Experimental observations are fairly consistent with the predictions by the present models. PMID:19505165

Firmansyah, Dudi Adi; Kim, Taeil; Kim, Songkil; Sullivan, Kyle; Zachariah, Michael R; Lee, Donggeun

2009-06-16

207

Blue green red luminescence from CeCl3- and MnCl2-doped hafnium oxide layers prepared by ultrasonic spray pyrolysis  

NASA Astrophysics Data System (ADS)

Hafnium oxide films doped with CeCl3 and/or MnCl2, and deposited at 300 °C by an ultrasonic spray pyrolysis process, were characterized using x-ray diffraction (XRD), energy-dispersive spectroscopy and photoluminescence. The XRD results revealed that the films are predominantly amorphous. The weak green-red emission of Mn2+ is enhanced through an efficient energy transfer from Ce3+ to Mn2+ ions. Spectroscopic data revealed that the energy transfer is nonradiative in nature and it could occur in Ce3+ and Mn2+ clusters through a short-range interaction mechanism. The efficiency of this transfer increases with the Mn2+ ion concentration, so that an efficiency of about 78% is attained for a 5 at.% of MnCl2 concentration, which makes these films interesting phosphors for the design of luminescent layers with blue, green and red emissions.

Martínez-Martínez, R.; García, M.; Speghini, A.; Bettinelli, M.; Falcony, C.; Caldiño, U.

2008-10-01

208

The Effect of Film Composition on the Texture and Grain Size of CuInS2 Prepared by Spray Pyrolysis  

NASA Technical Reports Server (NTRS)

Ternary single-source precursors were used to deposit CuInS2 thin films using chemical spray pyrolysis. We investigated the effect of the film composition on texture, secondary phase formation, and grain size. As-grown films were most often In-rich. They became more (204/220)-oriented as indium concentration increased, and always contained a yet unidentified secondary phase. The (112)-prefened orientation became more pronounced as the film composition became more Cu-rich. The secondary phase was determined to be an In-rich compound based on composition analysis and Raman spectroscopy. In addition, as-grown Cu-rich (112)-oriented films did not exhibit the In-rich compound. Depositing a thin Cu layer prior to the growth of CuInS2 increased the maximum grain size from - 0.5 micron to - 1 micron, and prevented the formation of the In-rich secondary phase.

Jin, Michael H.; Banger, Kulinder K.; Harris, Jerry D.; Hepp, Aloysius F.

2003-01-01

209

The Effect of Film Composition on the Texture and Grain Size of CuInS2 Prepared by Spray Pyrolysis  

NASA Technical Reports Server (NTRS)

CuInS2 was deposited by spray pyrolysis using single-source precursors synthesized in-house. Films with either (112) or (204/220) preferred orientation always showed Cu-rich and In-rich composition respectively. The In-rich (204/220)-oriented films always contained a secondary phase evaluated as an In-rich compound, and the hindrance of (112)-oriented grain growth was confirmed by glancing angle X-ray diffraction. In conclusion, only the Cu-rich (112)-oriented films with dense columnar grains can be prepared without the secondary In-rich compound. The effect of extra Cu on the grain size and the solar cell results will be also presented.

Jin, Michael H.-C.; Banger, Kulbinder K.; Harris, Jerry D.; Hepp, Aloysius F.

2003-01-01

210

Optical, electrical and structural properties of nano-pyramidal ZnO films grown on glass substrate by spray pyrolysis technique  

NASA Astrophysics Data System (ADS)

Optical, electrical and structural properties of ZnO nano-pyramidal films, synthesized by chemical spray pyrolysis technique on glass substrates were investigated. A complete set of structural, optical and electrical parameters is proposed in this contribution. ZnO films possess polycrystalline wurtzite structure showing a preferential orientation along the c-axis as confirmed by XRD measurements. The structure has been investigated by using Raman spectroscopy, at 532 nm excitation source and the morphology is characterized by scanning electron microscopy (SEM). Link to the specific growing parameters, the morphology of the so-obtained films is rarely observed in nanostructures family with a diameter of ZnO hexagonal nano-pyramids in the range of 50–150 nm smaller than this usually obtained by spray pyrolysis. The strong peaks of the E2 Raman mode at 99.3 cm?1 (low) and 439.4 cm?1 (high), indicate a good crystal quality of the ZnO nano-pyramids. The existence of a compressive stress in the ZnO structure was pointed out by Raman scattering and estimated by XRD measurements. High optical transmittance value of the film above 90% in the visible region was observed and the optical band gap was found to be 3.273 eV at room temperature. The photoluminescence (PL) spectrum of ZnO hexagonal pyramid shows an intensity ratio of the UV emission to the visible band more than 20. By electrical characterizations of the ZnO films, we obtained the values of the resistivity and Hall mobility equal to 17 ? cm and 8.49 cm2 V?1 s?1, respectively.

Bedia, A.; Bedia, F. Z.; Aillerie, M.; Maloufi, N.; Ould Saad Hamady, S.; Perroud, O.; Benyoucef, B.

2014-05-01

211

Analysis of drugs by pyrolysis. I. Selected ion monitoring combined with a pyrolysis method for the determination of carpronium chloride in biological samples.  

PubMed

In order to establish an analytical method for carpronium chloride, a parasympathomimetic agent, the pyrolysis reaction of carpronium chloride was examined in a g.c.m.s. system, which revealed that gamma-butyrolactone was produced directly from the drug as the main pyrolysis product. In the case of conversion of [2,2,3,3-2H4]carpronium chloride into the deuterated gamma-butyrolactone, 2H/1H scrambling was observed and confirmed to occur during the pyrolysis process of the deuterated compound. The proportion of gamma-[2H4]butyrolactone among the pyrolysis products was almost independent of the operating conditions, so [2,2,3,3-2H4]carpronium chloride was of practical use as an internal standard for selected ion monitoring. By incorporation of the pyrolysis reaction of carpronium chloride with selected ion monitoring and the use of [2,2,3,3-2H4]carpronium chloride as an internal standard, a rapid, sensitive and selective method was devised for the determination of the drug in biological samples. The method was utilized successfully for the biopharmaceutical studies of carpronium chloride in ma. PMID:912024

Ohya, K; Sano, M

1977-08-01

212

Pyrolysis Gas Flow in Thermally Ablating Media Using Time-Implicit Discontinuous Galerkin Methods.  

National Technical Information Service (NTIS)

In this work, we apply time-implicit discontinuous Galerkin methods to the problem of thermal ablation, where we solve for the dynamics of flow of pyrolysis gas in a charring ablating media. We have benchmarked our results with the published data. The pro...

A. Bhatia R. Gosse S. Roy

2011-01-01

213

Method for the gasification of carbonaceous matter by plasma arc pyrolysis  

Microsoft Academic Search

Apparatus and method for gasification of carbonaceous matter by plasma arc pyrolysis are disclosed. In one embodiment, a refractory-lined furnace is provided with a depression along its base for holding a pool of molten metal which acts as the external electrode for a bank of long arc column plasma torches which provide a heat mass for the process. The plasma

Camacho

1980-01-01

214

Predicting the generation of heavy oils in carbonate\\/evaporitic environments using pyrolysis methods  

Microsoft Academic Search

A series of low maturity kerogen and asphaltene samples of a sulphur-rich Mediterranean carbonate source rock sequence, as well as two associated oil samples were analysed by different pyrolysis methods. The source rock was characterised by the occurrence of four different lithotypes, three of which possessed source potential. Elemental analysis revealed that each source lithofacies contained a distinct kerogen type

R. Di Primio; B. Horsfield

1996-01-01

215

Influences of deposition and post-annealing temperatures on properties of TiO 2 blocking layer prepared by spray pyrolysis for solid-state dye-sensitized solar cells  

Microsoft Academic Search

Influences of the temperature (Ts) for spray pyrolysis deposition of TiO2 blocking layer (BL) using titanium diisopropoxide bis(acetylacetonate) (TAA) as a precursor and the temperature (Tp) for post-annealing of the BL films on the resulting BL film morphology and photovoltaic performance of solid-state dye-sensitized solar cells (SDSC) are investigated. A Ts ranging from 300 to 400°C is found preferable for

Changyun Jiang; Man Yin Leung; Wei Ling Koh; Yuning Li

2011-01-01

216

SYNTHESIS OF NANOSTRUCTURED LiM0.15Mn1.85O4 (M = Mn, Co, Al, AND Fe) PARTICLES BY SPRAY PYROLYSIS IN A FLUIDIZED BED REACTOR  

Microsoft Academic Search

A novel technique has been developed to directly produce fine ceramic powders from liquid solution via spray pyrolysis in a fluidized bed reactor (SPFBR). Using this technique the preparation of LiM0.15Mn1.85O4 (M = Mn, Co, Al, and Fe), which are the most promising cathode materials for lithium-ion batteries, has been carried out at a superficial velocity U0 of 0.71 m\\/s, a reactor temperature

Izumi Taniguchi; Shinya Nakajima; Zhumabay Bakenov

2008-01-01

217

Preparation and characterization of microparticles of piroxicam by spray drying and spray chilling methods  

PubMed Central

Piroxicam, an anti-inflammatory drug, exhibits poor water solubility and flow properties, poor dissolution and poor wetting. Consequently, the aim of this study was to improve the dissolution of piroxicam. Microparticles containing piroxicam were produced by spray drying, using isopropyl alcohol and water in the ratio of 40:60 v/v as solvent system, and spray chilling technology by melting the drug and chilling it with a pneumatic nozzle to enhance dissolution rate. The prepared formulations were evaluated for in vitro dissolution and solubility. The prepared drug particles were characterized by scanning electron microscopy (SEM), differential scanning calorimeter, X-ray diffraction and Fourier transform infrared spectroscopy. Dissolution profile of the spray dried microparticles was compared with spray-chilled microparticles, pure and recrystallized samples. Spray dried microparticles and spray chilled microparticles exhibited decreased crystallinity and improved micromeritic properties. The dissolution of the spray dried microparticle and spray chilled particles were improved compared with recrystallized and pure sample of piroxicam. Consequently, it was believed that spray drying of piroxicam is a useful tool to improve dissolution but not in case of spray chilling. This may be due to the degradation of drug or variations in the resonance structure or could be due to minor distortion of bond angles. Hence, this spray drying technique can be used for formulation of tablets of piroxicam by direct compression with directly compressible tablet excipients.

Dixit, M.; Kini, A.G.; Kulkarni, P.K.

2010-01-01

218

Cold spray modeling and validation using an optical diagnostic method  

Microsoft Academic Search

The Cold Gas Dynamic Spray process uses the kinetic energy of unmelted sprayed particles to produce coatings. The most important element of the cold spray system is the nozzle used to accelerate the particles. Consequently, the nozzle design optimisation is a key to improve the coating quality and reduce the spraying costs. In this study, an axi-symmetric two-dimensional mathematical model

B. Jodoin; F. Raletz; M. Vardelle

2006-01-01

219

Electrochemical properties of LiFe 0.9Mg 0.1PO 4 / carbon cathode materials prepared by ultrasonic spray pyrolysis  

NASA Astrophysics Data System (ADS)

The LiFe 0.9Mg 0.1PO 4/C powder of pure olivine phase can be prepared with the duplex process of spray pyrolysis synthesis (at 450 ?C) and subsequent heat treatment (at 700 ?C for 2, 4 and 8 h). From scanning electron microscopy observation with corresponding elemental mapping images of iron, phosphorous and magnesium, it could be found that the LiFe 0.9Mg 0.1PO 4 powders are covered with fine pyrolyzed carbon. Raman spectra indicate that the phase of carbon with higher electronic conductive phase is predominant when prolonged subsequent heat treatment is carried out. The carbon coatings on the LiFe 0.9Mg 0.1PO 4 surface can improve the conductivity of the LiFe 0.9Mg 0.1PO 4 powder (3.8×10 -5 S cm -1) to about a factor of ˜10 4 higher than the conductivity of LiFePO 4. The stability and cycle life of a charge/discharge cycle test of lithium ion secondary batteries are also enhanced. The results indicate that the LiFe 0.9Mg 0.1PO 4 powder, prepared at a pyrolysis temperature of 450 ?C and with post-heat-treatment at 700 ?C for 8 h, exhibits a specific initial discharge capacity of about 132 mA h g -1 at C/10 rate, 105 mA h g -1 at 1C, and 87 mA h g -1 at 5C.

Teng, Tsung-Hsien; Yang, Mu-Rong; Wu, She-hung; Chiang, Yi-Ping

2007-05-01

220

Application of Taguchi Method to the Optimization of Detonation Spraying Process  

Microsoft Academic Search

The present study deals with an application of the Taguchi method to the optimization of a detonation spray process for alumina coatings. Coating experiments were conducted using the TaguchUfractional factorial (L8) design parametric study to optimize spray process parameters. The Taguchi design evaluated the effects of four detonation spray process parameters: acetylene to oxygen ratio, carrier gas flow rate, frequency

P. Saravanan; V. Selvarajan; D. Srinivasa Rao; S. V. Joshi; G. Sundararajan

2000-01-01

221

Preparation of pyrolysis reference samples: evaluation of a standard method using a tube furnace.  

PubMed

A new, simple method for the reproducible creation of pyrolysis products from different materials that may be found at a fire scene is described. A temperature programmable steady-state tube furnace was used to generate pyrolysis products from different substrates, including softwoods, paper, vinyl sheet flooring, and carpet. The temperature profile of the tube furnace was characterized, and the suitability of the method to reproducibly create pyrolysates similar to those found in real fire debris was assessed. The use of this method to create proficiency tests to realistically test an examiner's ability to interpret complex gas chromatograph-mass spectrometric fire debris data, and to create a library of pyrolsates generated from materials commonly found at a fire scene, is demonstrated. PMID:22220974

Sandercock, P Mark L

2012-05-01

222

Pyrolysis combustion flow calorimetry  

Microsoft Academic Search

A method for evaluating the combustibility of milligram samples is described. Pyrolysis-combustion flow calorimetry (PCFC) separately reproduces the solid state and gas phase processes of flaming combustion in a nonflaming test by controlled pyrolysis of the sample in an inert gas stream followed by high temperature oxidation of the volatile pyrolysis products. Oxygen consumption calorimetry is used to measure the

Richard E Lyon; Richard N Walters

2004-01-01

223

Method and apparatus for atomization and spraying of molten metals  

SciTech Connect

A method and device for dispersing molten metal into fine particulate spray, the method comprises applying an electric current through the molten metal and simultaneously applying a magnetic field to the molten metal in a plane perpendicular to the electric current, whereby the molten metal is caused to form into droplets at an angle perpendicular to both the electric current and the magnetic field. The device comprises a structure for providing a molten metal, appropriately arranged electrodes for applying an electric current through the molten metal, and a magnet for providing a magnetic field in a plane perpendicular to the electric current.

Hobson, David O. (Oak Ridge, TN); Alexeff, Igor (Oak Ridge, TN); Sikka, Vinod K. (Clinton, TN)

1990-01-01

224

Method and apparatus for atomization and spraying of molten metals  

DOEpatents

A method and device for dispersing molten metal into fine particulate spray, the method comprises applying an electric current through the molten metal and simultaneously applying a magnetic field to the molten metal in a plane perpendicular to the electric current, whereby the molten metal is caused to form into droplets at an angle perpendicular to both the electric current and the magnetic field. The device comprises a structure for providing a molten metal, appropriately arranged electrodes for applying an electric current through the molten metal, and a magnet for providing a magnetic field in a plane perpendicular to the electric current. 11 figs.

Hobson, D.O.; Alexeff, I.; Sikka, V.K.

1988-07-19

225

Sn-Doped In2O3 Nanocrystalline Thin Films Deposited by Spray Pyrolysis: Microstructural, Optical, Electrical, and Formaldehyde-Sensing Characteristics  

NASA Astrophysics Data System (ADS)

Undoped and Sn-doped (1, 1.5 and 2 at.%) indium oxide (In2O3) thin films have been grown by the chemical spray pyrolysis technique on cleaned glass substrates using indium nitrate [In(NO3)3] and stannic tetrachloride hydrated (SnCl4·5H2O) as the host and dopant precursors, respectively, and deionized water as the solvent. Structural characterization using x-ray diffraction reveals that the films possess cubic structure, with the average crystallite size in the range 10-14 nm. The surface morphology and roughness of the films have been investigated by means of an atomic force microscope. UV-Vis measurements indicate an enhancement in the optical transmittance in the visible region on Sn doping. Further, the doping effect has been found to substantially reduce the electrical resistance to a few orders of magnitude of the undoped In2O3 film. We report a simultaneous improvement in both the optical and electrical properties of indium oxide thin film due to the doping of Sn ions. These results indicate that Sn-doped In2O3 thin film can be a potential candidate for use in various optoelectronic devices. Among all the films examined, the 1 at.% Sn-doped film shows the maximum response (~91%) at 300 °C for 80 ppm concentration of formaldehyde in air.

Pramod, N. G.; Pandey, S. N.; Sahay, P. P.

2013-08-01

226

Morphology control and luminescent property of Y{sub 3}Al{sub 5}O{sub 12}:Tb particles prepared by spray pyrolysis  

SciTech Connect

A spray pyrolysis process was used to prepare spherical yttrium aluminum garnet (Y{sub 3}Al{sub 5}O{sub 12}:Tb) phosphor particles with enhanced luminescence properties. The aim of the process was to improve the morphology and luminescent intensity of the Y{sub 3}Al{sub 5}O{sub 12}:Tb phosphor particles by modifying the precursor solution. The particles produced from a nitrate aqueous solution were spherical with a hollow structure that was deformed by the post treatment at 1400 deg. C. To avoid the hollowness, the nitrate solution was modified by the addition of an NH{sub 4}OH solution so that a polycation solution could be obtained. Compared with the hollow particles prepared from the nitrate aqueous solution, the Y{sub 3}Al{sub 5}O{sub 12}:Tb particles with the spherical morphology and nonaggregated structure, even after the post treatment, were successfully prepared and found to have an improved photoluminescence and cathodoluminescence intensity.

Jung, Kyeong Youl [Advanced Materials Division, Korea Research Institute of Chemical Technology, 100 Jang-dong, Yuseong-gu, Daejeon 305-343 (Korea, Republic of)]. E-mail: kyjung@krict.re.kr; Lee, Dong Youl [Advanced Materials Division, Korea Research Institute of Chemical Technology, 100 Jang-dong, Yuseong-gu, Daejeon 305-343 (Korea, Republic of); Kang, Yun Chan [Department of Chemical Engineering, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701 (Korea, Republic of)

2005-12-08

227

Preparation and characterization of nanostructures of in-doped ZnO films deposited by chemically spray pyrolysis: Effect of substrate temperatures  

NASA Astrophysics Data System (ADS)

We deposited undoped (ZnO) and indium-doped ZnO (IZO) films onto glass substrate via ultrasonic spray pyrolysis technique. The variation in structural, surface morphology, electrical, optical and photoluminescent properties as a function of substrate temperature is investigated. X-rays pattern confirms that as-synthesized IZO phase is grown along a (002) preferential plane. Nanosized grains (<50 nm) are determined by X-ray analysis. Morphology of as-grown films shows broadened nanostructures which have grown along c-axis and nanostructures are found to be smooth (RMS˜60 nm). Study by spectrophotometer reveals that the as-grown films are highly transparent in the visible and IR spectra (T ˜ 88%), and that the bandgap is slightly narrowed (3.17 eV). Electrical measurements confirm the enhancement of conductivity, ? < 1 ? cm, due to indium incorporation into the starting solution. An electron concentration of 1017 cm-3 and a mobility of 3 cm2/Vs are found for IZO films grown at 400 °C. The photoluminescence analysis demonstrates strong yellow (2.1 eV) and blue (2.8 eV) light and weak green (2.3 eV) emissions.

Benhaliliba, M.; Benouis, C. E.; Mouffak, Z.; Ocak, Y. S.; Tiburcio-Silver, A.; Aida, M. S.; Garcia, A. A.; Tavira, A.; Sanchez Juarez, A.

2013-11-01

228

Improving electrical performance of ultrasonic spray pyrolysis grown textured ZnO films by introducing In2O3:W interface layer  

NASA Astrophysics Data System (ADS)

The main focus of this paper was the improvement in the Hall mobility of ZnO films prepared by ultrasonic spray pyrolysis. In order to achieve low resistivity and high transparency simultaneously, we used the tungsten doped In2O3 (IWO) deposited by electron beam evaporation as interface layer to prepare IWO/ZnO films. Hall mobility can be improved to close to 50 cm2 V-1 s-1, and the resistivity kept as low as 1.48 × 10-3 ? cm, while the transparency of the IWO/ZnO was about 80% in the range of 400-2000 nm (including glass) at the same time. X-ray diffraction and scanning electron microscope measurements were used to investigate the structure properties and surface morphologies of the ZnO and IWO/ZnO films. Secondary ion mass spectrometry measurement revealed that the indium and tungsten can diffuse from the IWO layer into the following deposited ZnO layer. The oxygen interstitial of the ZnO layer can be decreased by the tungsten diffusing from the IWO layer, and this was the main reason of the higher Hall mobility. Atom force microscopy measurement indicated the IWO/ZnO films with high value texture.

Jiao, Bao-chen; Zhang, Xiao-dan; Wei, Chang-chun; Huang, Qian; Chen, Xin-liang; Zhao, Ying

2013-08-01

229

Photoelectrochemical performances of n-CdS{sub 1-x}Se{sub x} thin films prepared by spray pyrolysis technique  

SciTech Connect

The CdS{sub 1-x}Se{sub x} (0.0 {<=} x {<=} 1.0) thin films of various compositions have been deposited onto the amorphous and FTO coated glass substrates using a spray pyrolysis technique. An electrode/electrolyte interface has been formed between an n-type CdS{sub 1-x}Se{sub x} (0.0 {<=} x {<=} 1.0) alloyed/mixed type semiconductor and a sulphide/polysulphide redox electrolyte and investigated through the current-voltage, capacitance-voltage and photovoltaic power output characteristics. The dependence of the dark current through the junction and the junction capacitance on the voltage across the junction have been examined and analysed. Upon illumination of the interface with a light of 20 mW/cm{sup 2}, an open-circuit voltage of the order of 335 mV and a short-circuit current of 1.02 mA/cm{sup 2} have been developed (for x = 0.8), which results in energy conversion efficiency and fill factor 0.79% and 0.46% respectively. The magnitudes of the barrier heights at the interfaces have been determined. The significant electrochemical properties have been observed for a cell with electrode composition x = 0.8. (author)

Yadav, A.A.; Masumdar, E.U. [Thin Film Physics Laboratory, Department of Physics, Electronics and Photonics, Rajarshi Shahu Mahavidyalaya, Latur-413 512, Maharashtra (India)

2010-08-15

230

Spray pyrolysis of tin selenide thin-film semiconductors: the effect of selenium concentration on the properties of the thin films  

NASA Astrophysics Data System (ADS)

Thin films of tin selenide (SnxSey) with an atomic ratio of , 1 and 1.5 were prepared on a glass substrate at T = 470°C using a spray pyrolysis technique. The initial materials for the preparation of the thin films were an alcoholic solution consisting of tin chloride (SnCl4· 5H2O) and selenide acide (H2SeO3). The prepared thin films were characterized by X-ray diffraction (XRD), scanning electron microscopy, scanning tunneling microscopy, scanning helium ion microscopy, and UV-vis spectroscopy. The photoconductivity and thermoelectric effects of the SnxSey thin films were then studied. The SnxSey thin films had a polycrystalline structure with an almost uniform surface and cluster type growth. The increasing atomic ratio of r in the films, the optical gap, photosensitivity and Seebeck coefficient were changed from 1.6 to 1.37 eV, 0.01 to 0.31 and -26.2 to -42.7 mV/K (at T = 350 K), respectively. In addition, the XRD patterns indicated intensity peaks in r = 1 that corresponded to the increase in the SnSe and SnSe2 phases.

Fadavieslam, M. R.; Bagheri-Mohagheghi, M. M.

2013-08-01

231

Preparation and characterization of indium doped CdS{sub 0.2}Se{sub 0.8} thin films by spray pyrolysis  

SciTech Connect

The CdS{sub 0.2}Se{sub 0.8} and indium doped CdS{sub 0.2}Se{sub 0.8} thin films have been deposited onto the amorphous glass and fluorine doped tin oxide coated glass substrates by spray pyrolysis. The doping concentration of indium has been optimized by photoelectrochemical characterization technique. The structural, surface morphological, optical and electrical properties of CdS{sub 0.2}Se{sub 0.8} and indium doped CdS{sub 0.2}Se{sub 0.8} thin films have been studied. X-ray diffraction studies reveal that the films are polycrystalline in nature with hexagonal crystal structure. Scanning electron microscopy studies reveal that the grains are uniform with uneven spherically shaped, distributed over the entire substrate surface. The complete surface morphology has been changed after doping. In optical studies, the transition of the deposited films is found to be direct allowed with optical energy gaps decreasing from 1.91 to 1.67 eV with indium doping. Semiconducting behavior has been observed from resistivity measurements. The thermoelectric power measurements reveal that the films exhibit n-type conductivity.

Yadav, A.A., E-mail: aay_physics@yahoo.co.in [Thin Film Physics Laboratory, Department of Physics, Electronics and Photonics, Rajarshi Shahu Mahavidyalaya, Latur 413512, Maharashtra (India); Masumdar, E.U. [Thin Film Physics Laboratory, Department of Physics, Electronics and Photonics, Rajarshi Shahu Mahavidyalaya, Latur 413512, Maharashtra (India)] [Thin Film Physics Laboratory, Department of Physics, Electronics and Photonics, Rajarshi Shahu Mahavidyalaya, Latur 413512, Maharashtra (India)

2010-10-15

232

Effect of Sb dopant on the structural, optical and electrical properties of SnS thin films by spray pyrolysis technique.  

PubMed

Thin films of antimony doped tin sulphide (SnS:Sb) with different antimony concentrations have been prepared by the spray pyrolysis technique at the substrate temperature of 350°C. The physical properties of the films were studied as a function of increase in antimony dopant concentration (up to 10at.%). The films were characterized by different techniques to study their structural, optical and electrical properties. The X-ray diffraction analysis revealed that the films were polycrystalline in nature and having orthorhombic crystal structure with a preferred orientation in (111) direction. Due to Sb doping, the crystalline quality and the preferential orientation of SnS films were improved up to 6at.% of doping concentration. However, when doping concentration was increased above 6at.%, the crystalline quality and the preferential orientation of SnS films was deteriorated. Atomic force microscopy images revealed that the surface roughness of the films increased due to Sb doping. Optical measurements showed that the band gap values decreased from 1.60eV to 1.15eV with increase in Sb concentration. The photoluminescence spectra displayed that all the samples have an emission peak centered at 760nm. At 6at.% of Sb doping, the film has the lowest resistivity of 2.598×10(-2)?cm while the carrier concentration was high. PMID:23892347

Santhosh Kumar, K; Manoharan, C; Dhanapandian, S; Gowri Manohari, A

2013-11-01

233

Method and apparatus for atomization and spraying of molten metals  

SciTech Connect

This patent describes a method and device for dispersing molten metal into fine particulate spray. It comprises applying an electric current through the molten metal and simultaneously applying a magnetic field to the molten metal in a plane perpendicular to the electric current, whereby the molten metal is caused to form into droplets at an angle perpendicular to both the electric current and the magnetic field. The device comprises a structure for providing a molten metal, appropriately arranged electrodes for applying an electric current through the molten metal, and a magnet for providing a magnetic field in a plane perpendicular to the electric current.

Hobson, D.O.; Alexeff, I.; Sikka, V.K.

1990-04-24

234

Molecular characterization and comparison of shale oils generated by different pyrolysis methods  

USGS Publications Warehouse

Shale oils generated using different laboratory pyrolysis methods have been studied using standard oil characterization methods as well as Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) with electrospray ionization (ESI) and atmospheric photoionization (APPI) to assess differences in molecular composition. The pyrolysis oils were generated from samples of the Mahogany zone oil shale of the Eocene Green River Formation collected from outcrops in the Piceance Basin, Colorado, using three pyrolysis systems under conditions relevant to surface and in situ retorting approaches. Significant variations were observed in the shale oils, particularly the degree of conjugation of the constituent molecules and the distribution of nitrogen-containing compound classes. Comparison of FT-ICR MS results to other oil characteristics, such as specific gravity; saturate, aromatic, resin, asphaltene (SARA) distribution; and carbon number distribution determined by gas chromatography, indicated correspondence between higher average double bond equivalence (DBE) values and increasing asphaltene content. The results show that, based on the shale oil DBE distributions, highly conjugated species are enriched in samples produced under low pressure, high temperature conditions, and under high pressure, moderate temperature conditions in the presence of water. We also report, for the first time in any petroleum-like substance, the presence of N4 class compounds based on FT-ICR MS data. Using double bond equivalence and carbon number distributions, structures for the N4 class and other nitrogen-containing compounds are proposed.

Birdwell, Justin E.; Jin, Jang Mi; Kim, Sunghwan

2012-01-01

235

Facile synthesis of antimony-doped tin oxide nanoparticles by a polymer-pyrolysis method  

SciTech Connect

In this article, antimony-doped tin oxide (ATO) nanoparticles was synthesized by a facile polymer-pyrolysis method. The pyrolysis behaviors of the polymer precursors prepared via in situ polymerization of metal salts and acrylic acid were analyzed by simultaneous thermogravimetric and differential scanning calorimetry (TG-DSC). The structural and morphological characteristics of the products were studied by powder X-ray diffraction (XRD) and transmission electron microscope (TEM). The results reveal that the ATO nanoparticles calcined at 600 {sup o}C show good crystallinity with the cassiterite structure and cubic-spherical like morphology. The average particle size of ATO decreases from 200 to 15 nm as the Sb doping content increases from 5 mol% to 15 mol%. Electrical resistivity measurement shows that the resistivity for the 10-13 mol% Sb-doped SnO{sub 2} nanoparticles is reduced by more than three orders compared with the pure SnO{sub 2} nanoparticles. In addition, due to its versatility this polymer-pyrolysis method can be extended to facile synthesis of other doped n-type semiconductor, such as In, Ga, Al doped ZnO, Sn doped In{sub 2}O{sub 3}.

Li, Yuan-Qing, E-mail: yqli@mail.ipc.ac.cn [School of Materials Science and Engineering, Shijiazhuang Railway Institute, Shijiazhuang 050043 (China)] [School of Materials Science and Engineering, Shijiazhuang Railway Institute, Shijiazhuang 050043 (China); Wang, Jian-Lei [School of Materials Science and Engineering, Shijiazhuang Railway Institute, Shijiazhuang 050043 (China)] [School of Materials Science and Engineering, Shijiazhuang Railway Institute, Shijiazhuang 050043 (China); Fu, Shao-Yun, E-mail: syfu@mail.ipc.ac.cn [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China)] [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Mei, Shi-Gang; Zhang, Jian-Min; Yong, Kang [School of Materials Science and Engineering, Shijiazhuang Railway Institute, Shijiazhuang 050043 (China)] [School of Materials Science and Engineering, Shijiazhuang Railway Institute, Shijiazhuang 050043 (China)

2010-06-15

236

A three-dimensional model of the spray forming method  

Microsoft Academic Search

A three-dimensional model has been formulated to calculate the shape of the general preform, using vector calculus. The shape\\u000a of a rod, tube, plate, or irregular preform can be calculated at given spray forming conditions. The shape of a spray-formed\\u000a rod was analyzed at various spray forming conditions using the three-dimensional model. The effects of spray forming parameters,\\u000a such as

Hyun-Kwang Seok; Kyu Hwan Oh; Hyung Yong Ra; Dong-Hun Yeo; Ho-In Lee

1998-01-01

237

Preparation and electrical properties of Ga-doped ZnO nanoparticles by a polymer pyrolysis method  

Microsoft Academic Search

In this article, preparation of Ga-doped zinc oxide (GZO) nanoparticles by a polymer pyrolysis method is reported. The pyrolysis behaviors of the polymer precursors prepared via the in situ polymerization of metal salts and acrylic acid are analyzed using thermalgravity-differential scanning calorimetry (TG-DSC) techniques. Then, the structural characteristics of the products are studied by X-ray diffraction (XRD) and transmission electron

Yuan-Qing Li; Kang Yong; Hong-Mei Xiao; Wang-Jing Ma; Guang-Lei Zhang; Shao-Yun Fu

2010-01-01

238

Colloidal spray method for low cost thin coating deposition  

DOEpatents

A dense or porous coating of material is deposited onto a substrate by forcing a colloidal suspension through an ultrasonic nebulizer and spraying a fine mist of particles in a carrier medium onto a sufficiently heated substrate. The spraying rate is essentially matched to the evaporation rate of the carrier liquid from the substrate to produce a coating that is uniformly distributed over the surface of the substrate. Following deposition to a sufficient coating thickness, a single sintering step may be used to produce a dense ceramic coating. Using this method, coatings ranging in thickness from about one to several hundred microns can be obtained. By using a plurality of compounds in the colloidal suspension, coatings of mixed composition can be obtained. By using a plurality of solutions and separate pumps and a single or multiple ultrasonic nebulizer(s), and varying the individual pumping rates and/or the concentrations of the solutions, a coating of mixed and discontinuously graded (e.g., stepped) or continuously graded layers may be obtained. This method is particularly useful for depositing ceramic coatings. Dense ceramic coating materials on porous substrates are useful in providing improved electrode performance in devices such as high power density solid oxide fuel cells. Dense ceramic coatings obtained by the invention are also useful for gas turbine blade coatings, sensors, steam electrolyzers, etc. The invention has general use in preparation of systems requiring durable and chemically resistant coatings, or coatings having other specific chemical or physical properties.

Pham, Ai-Quoc (San Jose, CA); Glass, Robert S. (Livermore, CA); Lee, Tae H. (Naperville, IL)

2002-01-01

239

Spray automated balancing of rotors: Methods and materials  

NASA Technical Reports Server (NTRS)

The work described consists of two parts. In the first part, a survey is performed to assess the state of the art in rotor balancing technology as it applies to Army gas turbine engines and associated power transmission hardware. The second part evaluates thermal spray processes for balancing weight addition in an automated balancing procedure. The industry survey reveals that: (1) computerized balancing equipment is valuable to reduce errors, improve balance quality, and provide documentation; (2) slow-speed balancing is used exclusively, with no forseeable need for production high-speed balancing; (3) automated procedures are desired; and (4) thermal spray balancing is viewed with cautious optimism whereas laser balancing is viewed with concern for flight propulsion hardware. The FARE method (Fuel/Air Repetitive Explosion) was selected for experimental evaluation of bond strength and fatigue strength. Material combinations tested were tungsten carbide on stainless steel (17-4), Inconel 718 on Inconel 718, and Triballoy 800 on Inconel 718. Bond strengths were entirely adequate for use in balancing. Material combinations have been identified for use in hot and cold sections of an engine, with fatigue strengths equivalent to those for hand-ground materials.

Smalley, Anthony J.; Baldwin, Richard M.; Schick, Wilbur R.

1988-01-01

240

Numerical modeling of spray combustion with an advanced VOF method  

NASA Technical Reports Server (NTRS)

This paper summarizes the technical development and validation of a multiphase computational fluid dynamics (CFD) numerical method using the volume-of-fluid (VOF) model and a Lagrangian tracking model which can be employed to analyze general multiphase flow problems with free surface mechanism. The gas-liquid interface mass, momentum and energy conservation relationships are modeled by continuum surface mechanisms. A new solution method is developed such that the present VOF model can be applied for all-speed flow regimes. The objectives of the present study are to develop and verify the fractional volume-of-fluid cell partitioning approach into a predictor-corrector algorithm and to demonstrate the effectiveness of the present approach by simulating benchmark problems including laminar impinging jets, shear coaxial jet atomization and shear coaxial spray combustion flows.

Chen, Yen-Sen; Shang, Huan-Min; Shih, Ming-Hsin; Liaw, Paul

1995-01-01

241

Cu doping: An effective method for improving optoelectronic properties of sprayed SnS thin films  

NASA Astrophysics Data System (ADS)

SnS thin films were deposited using Chemical Spray Pyrolysis (CSP) technique at a substrate temperature of 415 °C. Resistivity of pristine SnS thin film was 120 ?.cm. In order to decrease resistivity, in-situ copper doping was done and its effects on the structural, optical and electrical properties were studied. Percentage of Cu was varied as 2%, 4%, 6%, 8% and 10% of tin in the precursor solution. Resistivity decreased with minimum resistivity of 1.6 ?.cm for the sample doped with 6% copper. Beyond 6 % doping, resistivity increased. All the films were n type irrespective of doping.

Ninan, Gisa Grace; Rajeshmon, V. G.; Kartha, C. Sudha; Vijayakumar, K. P.

2014-04-01

242

Structure and optical band gap of ZnO1-xSx thin films synthesized by chemical spray pyrolysis for application in solar cells  

NASA Astrophysics Data System (ADS)

Highly crystalline c-axis oriented and homogeneous ZnO1-xSx films with sulfur composition 0.05 <= x <= 0.9 without phase separation were deposited using spray pyrolysis of aqueous precursors. A mechanism of film growth is proposed which envisages a slower kinetics of ZnO precursor decomposition and its specific by-products combined with S-precursor decomposition which enables homogeneous ZnO1-xSx phase formation over a wide S-composition range 0.05 <= x <= 0.9. This is achieved by controlling the substrate temperature to <= 300 °C and the spray rate at ~ 3 ml/min. The ZnO1-xSx films primarily form by S2- substitution at the O2- lattice sites which is confirmed by detailed analysis of the Zn2p, S2p and O1s x-ray photoelectron spectroscopy peaks. With the increasing of S-content, a structural transformation is observed in ZnO1-xSx films; for x < 0.3, the ZnO1-xSx films in the oxygen-rich phase are in ZnO wurtzite crystal structure and for x >= 0.44, the ZnO1-xSx films lie in the sulfur-rich phase with ?-ZnS structure. At threshold x = 0.3, in the structural transition state, diffraction peaks corresponding to both structural phases are observed. The optical transmission spectra at the band gap transition energy position shift to the red side for 0.05 <= x < 0.52 and towards the blue side with the further increase in S-content in the 0.52 < x <= 0.9 range. Optical band gap energy determined for ZnO1-xSx films show strong band gap bowing over the entire S-composition range, 0.05 <= x <= 0.9. The band gap modulation with increased S-content is inconsistent with the use of a single bowing parameter. A bowing parameter of 2.5 eV shows a closer fit for 0.05 <= x < 0.52. By accounting for additional effect of the strain energy on the band gap due to addition of excess S-content, a closer fit for the observed variation in the band gap is explained in the 0.52 < x <= 0.9 composition range. Electrical resistivity variation with S-content is consistent with the compensating effect of S2- substitution at the O2- sites in ZnO1-xSx films.

Thankalekshmi, Ratheesh R.; Rastogi, A. C.

2012-09-01

243

Spray-spinning: a novel method for making alginate\\/chitosan fibrous scaffold  

Microsoft Academic Search

The subject of our investigations was the process of obtaining alginate\\/chitosan polyelectrolyte complex (PEC) fibers. In\\u000a this study, a novel method named “spray-spinning” was developed for the making of these hybrid fibers. In spray-spinning,\\u000a a chitosan solution was sprayed into a flowing sodium alginate solution and sheared into streamlines. The elongated streamlines\\u000a subsequently transformed into alginate\\/chitosan PEC fibers. Average diameter

Jian-Zheng Wang; Xiao-Bo Huang; Jing Xiao; Nan Li; Wei-Ting Yu; Wei Wang; Wei-Yang Xie; Xiao-Jun Ma; Ying-Li Teng

2010-01-01

244

Preparation and characteristics of a BaO-Al2O3B2O3SiO2La2O3 glass ceramic via spray pyrolysis  

Microsoft Academic Search

The characteristics of a BaO-Al2O3-B2O3-SiO2-La2O3 glass ceramic prepared by spray pyrolysis were studied. Glass powders with spherical shape and amorphous phase were prepared by complete melting at a preparation temperature of 1 500°C. The mean size and geometric standard deviation of the powders prepared at the temperature of 1 500°C were 0.6 mum and 1.3. The glass powders had similar

D. S. Jung; Y. C. Kang

2009-01-01

245

Preparation and characteristics of a BaO–Al 2 O 3 –B 2 O 3 –SiO 2 –La 2 O 3 glass ceramic via spray pyrolysis  

Microsoft Academic Search

The characteristics of a BaO–Al2O3–B2O3–SiO2–La2O3 glass ceramic prepared by spray pyrolysis were studied. Glass powders with spherical shape and amorphous phase were prepared\\u000a by complete melting at a preparation temperature of 1?500°C. The mean size and geometric standard deviation of the powders\\u000a prepared at the temperature of 1?500°C were 0.6 ?m and 1.3. The glass powders had similar composition to

D. S. Jung; Y. C. Kang

2009-01-01

246

Understanding the sprayed boric acid method for bulk doping of silicon ribbons  

NASA Astrophysics Data System (ADS)

The sprayed boric acid (SBA) method for bulk doping of silicon ribbons is investigated. Experimental procedures and main results are reviewed. Computational fluid dynamics and experimental tests using partial spraying suggest the role of gas transported evaporated boron oxide to explain the boron incorporation profiles along the sample. The industrial applicability of the SBA method is discussed.

Silva, J. A.; Pêra, David; Brito, Miguel C.; Alves, Jorge Maia; Serra, João; Vallêra, A. M.

2011-07-01

247

Plasma resistant aluminum oxide coatings for semiconductor processing apparatus by atmospheric aerosol spray method  

Microsoft Academic Search

To decrease the amount of contaminant particles generated during semiconductor manufacturing processes, coatings that can prevent erosion on the inner surfaces and parts of the chamber are required. In this study, plasma resistant dense Al2O3 film was formed on a silicon substrate through the atmospheric aerosol spray method (AAS). AAS is a novel powder spray method, which can form a

Hoomi Choi; Kwangsu Kim; Heesung Choi; Sangwoo Kang; Juyoung Yun; Yonghyeon Shin; Taesung Kim

2010-01-01

248

Manual fire suppression methods on typical machinery space spray fires  

Microsoft Academic Search

A series of tests was conducted to evaluate the effectiveness of Aqueous Film Forming Foam (AFFF), potassium bicarbonate powder (PKP) and Halon 1211, alone and in various combinations, in extinguishing spray fires. The sprays were generated by JP-5 jet fuel issuing from an open sounding tube, and open petcock, a leaking flange or a slit pipe, and contacting an ignition

H. W. Carhart; J. T. Leonard; E. K. Budnick; R. J. Ouellette; J. H. Shanley Jr.

1990-01-01

249

Material design of ceramic coating by plasma spray method  

Microsoft Academic Search

In the ceramic coating on substrate, cracking and peeling occur due to the difference of thermal expansion between substrate material and coating material. For evaluation of peeling property of plasma sprayed coating, it is demanded that thermal properties of plasma sprayed coating are estimated in detail. In this study, the results of comparison of thermal properties between bulk material and

Masaru Nakamichi; Takeshi Takabatake; Hiroshi Kawamura

1998-01-01

250

Methods for coating conduit interior surfaces utilizing a thermal spray gun with extension arm  

DOEpatents

Systems and methods for applying a coating to an interior surface of a conduit. In one embodiment, a spray gun configured to apply a coating is attached to an extension arm which may be inserted into the bore of a pipe. The spray gun may be a thermal spray gun adapted to apply a powder coating. An evacuation system may be used to provide a volume area of reduced air pressure for drawing overspray out of the pipe interior during coating. The extension arm as well as the spray gun may be cooled to maintain a consistent temperature in the system, allowing for more consistent coating.

Moore, Karen A. (Idaho Falls, ID); Zatorski, Raymond A. (East Hampton, CT)

2007-10-02

251

Effects of synthesis conditions on the physical and electrochemical properties of Li1.2Mn0.54Ni0.13Co0.13O2 prepared by spray pyrolysis  

NASA Astrophysics Data System (ADS)

Layered Li1.2Mn0.54Ni0.13Co0.13O2 materials were synthesized via spray pyrolysis. Synthesis conditions were varied in order to understand their effect on the electrochemical properties of the material. Three process parameters were evaluated: aerosol flow rate, reactor wall temperature and precursor concentration. Electrochemical results show excellent batch-to-batch reproducibility and no non-uniformities, as measured by energy dispersive X-ray spectroscopy (EDX). Phase purity is maintained for all the samples as measured by powder X-ray diffraction (XRD). The primary particle size has the most significant effect on the electrochemical performance of the materials with smaller primary particles promoting electrochemical activation and increasing capacity. Discharge capacities exceeding 200 mAh g-1 after 100 cycles at C/3 rate (where 1C = 200 mAh g-1) are consistently obtained over a wide range of operating conditions. Spray pyrolysis is shown to be a promising, robust synthesis technique for the production of Li1.2Mn0.54Ni0.13Co0.13O2 material, delivering excellent electrochemical performance within a wide range of process conditions.

Lengyel, Miklos; Atlas, Gal; Elhassid, Dror; Luo, Peter Y.; Zhang, Xiaofeng; Belharouak, Ilias; Axelbaum, Richard L.

2014-09-01

252

Development of Proposed Standard Test Method for Spray Painting Transfer Efficiency. Volume 2. Verification Program.  

National Technical Information Service (NTIS)

The two-volume report gives results of a program to develop and verify a standardized spray-painting transfer-efficiency test method. Both review of the literature and laboratory research were conducted. Transfer efficiency measurement methods presently u...

K. C. Kennedy

1988-01-01

253

Method and apparatus for heat extraction by controlled spray cooling  

SciTech Connect

Two solutions to the problem of cooling a high temperature, high heat flux surface using controlled spray cooling are presented for use on a mandrel. In the first embodiment, spray cooling is used to provide a varying isothermal boundary layer on the side portions of a mandrel by providing that the spray can be moved axially along the mandrel. In the second embodiment, a spray of coolant is directed to the lower temperature surface of the mandrel. By taking advantage of super-Leidenfrost cooling, the temperature of the high temperature surface of the mandrel can be controlled by varying the mass flux rate of coolant droplets. The invention has particular applicability to the field of diamond synthesis using chemical vapor deposition techniques.

NONE

1999-11-30

254

Method and apparatus for heat extraction by controlled spray cooling  

DOEpatents

Two solutions to the problem of cooling a high temperature, high heat flux surface using controlled spray cooling are presented for use on a mandrel. In the first embodiment, spray cooling is used to provide a varying isothermal boundary layer on the side portions of a mandrel by providing that the spray can be moved axially along the mandrel. In the second embodiment, a spray of coolant is directed to the lower temperature surface of the mandrel. By taking advantage of super-Leidenfrost cooling, the temperature of the high temperature surface of the mandrel can be controlled by varying the mass flux rate of coolant droplets. The invention has particular applicability to the field of diamond synthesis using chemical vapor deposition techniques.

Edwards, Christopher Francis (5492 Lenore Ave., Livermore, Alameda County, CA 94550); Meeks, Ellen (304 Daisyfield Dr., Livermore, Alameda County, CA 94550); Kee, Robert (864 Lucille St., Livermore, Alameda County, CA 94550); McCarty, Kevin (304 Daisyfield Dr., Livermore, Alameda County, CA 94550)

1999-01-01

255

Genetic programming:? a novel method for the quantitative analysis of pyrolysis mass spectral data.  

PubMed

A technique for the analysis of multivariate data by genetic programming (GP) is described, with particular reference to the quantitative analysis of orange juice adulteration data collected by pyrolysis mass spectrometry (PyMS). The dimensionality of the input space was reduced by ranking variables according to product moment correlation or mutual information with the outputs. The GP technique as described gives predictive errors equivalent to, if not better than, more widespread methods such as partial least squares and artificial neural networks but additionally can provide a means for easing the interpretation of the correlation between input and output variables. The described application demonstrates that by using the GP method for analyzing PyMS data the adulteration of orange juice with 10% sucrose solution can be quantified reliably over a 0-20% range with an RMS error in the estimate of ?1%. PMID:21639171

Gilbert, R J; Goodacre, R; Woodward, A M; Kell, D B

1997-11-01

256

Methode de Fabrication de Materiaux Photovoltaiques par Pulverisation Chimique Spray (Fabrication Method for Photovoltaic Materials by Chemical Atomisation Spray).  

National Technical Information Service (NTIS)

Acetonitrile has been shown to be a suitable carrier solvent for the preparation of thin layers of cuprous sulphide by chemical atomisation. A reactive spraying apparatus for monodispersed mist has been developed. It is claimed to be indispensible for est...

M. Savelli J. LaHaye J. Vedel

1982-01-01

257

Solid waste utilization: pyrolysis  

Microsoft Academic Search

As a part of the Integrated Community Energy System (ICES) Program, a number of technology evaluations are being prepared on various current and emerging sources of energy. This evaluation considers the use of pyrolysis as a method of producing energy from municipal solid waste. The energy can be in the form of a gas, oil, chars, or steam. Pyrolysis, the

W. J. Jr. Boegly; W. R. Mixon; C. Dean; D. J. Lizdas

1977-01-01

258

Second chance for pyrolysis  

Microsoft Academic Search

Reports on how pyrolysis is being used not only for breaking down municipal waste, plastics and tires but also for handling toxic wastes that can foul incinerators. One big advantage over conventional disposal methods (e.g. incineration) is that the contaminants don't pass on to the gaseous emissions and foul up downstream units. Key to the pyrolysis unit will be a

L. Kaplan; R. Lewald; H. Short; S. Ushio

1982-01-01

259

Emulsion Combustion and Flame Spray Synthesis of Zinc Oxide\\/Silica Particles  

Microsoft Academic Search

Two flame spray methods, emulsion combustion method (ECM) and flame spray pyrolysis (FSP), were compared for synthesis of pure and mixed SiO2 and ZnO nanoparticles. The effect of silicon precursor was investigated using liquid hexamethyldisiloxane (HMDSO) or SiO2 sol, while for ZnO zinc acetate (ZA) was used. Gas phase reaction took place when using HMDSO as Si precursor, forming nanoparticles,

Takao Tani; Naoyoshi Watanabe; Kazumasa Takatori

2003-01-01

260

Repair of Damaged Mold Surface by Cold-Spray Method  

Microsoft Academic Search

Thermal-mechanical loads during molding can cause wearing of the surfaces of the molds. In this research, a mold repair technique at low temperature was developed by applying cold-spray deposition. Aluminum particles were deposited on top of the damaged aluminum mold. The original mold surface was recovered by milling the deposited material. Material properties such as hardness, coefficient of thermal expansion,

J. C. Lee; H. J. Kang; W. S. Chu; S. H. Ahn

2007-01-01

261

Mixed-metal oxide nanopowders by liquid-feed flame spray pyrolysis (LF-FSP): Synthesis and processing of core-shell nanoparticles  

NASA Astrophysics Data System (ADS)

In this dissertation, liquid feed--flame spray pyrolysis (LF-FSP) was used for the synthesis and characterization of mixed-metal oxide nanopowders in the Ce-Zr-Al-O system for potential catalytic, photonic, electronic and structural applications. The LF-FSP process aerosolizes metalloorganic precursors dissolved in an alcohol solvent with oxygen, combusts the aerosol, and then rapidly quenches the gaseous species to produce nanosize oxide "soot" with the same compositions as those in the starting precursor solutions. The wide variety of potential metal oxide precursors allows the synthesis of multiple chemical compositions, phase and unique particle morphologies in the resulting nanopowders. Surprisingly, LF-FSP with the correct choice of metalloorganic precursors provides access to core-shell nanopowders in a single step. The (ZrOx)x(Al2O3 )1-x system was explored first for potential structural applications as zirconia toughened alumina (ZTA) composites. During the LF-FSP process, core-shell nanoparticles with ?-alumina shell and tetragonal zirconia core form at (ZrO2)x(Al2O3) 1-x (x = 0.4-0.8). Evidence is presented suggesting the incorporation of Zr2+/3+ ions in the ?-alumina lattice. The (CeOx)x(Al2O3)1-x system was studied for potential catalytic and photonic applications. Small amounts of Ce3+ ions substitute into the ?-alumina lattice at all concentrations and Ce-magnetoplumbite is observed at 5-10 mole % CeOx concentrations. The CexZr1-xO2 and (Ce0.7Zr 0.3O2)x(Al2O3)1-x systems were also investigated for potential catalytic applications. We were able to produce nano-size single crystal Ce1- xZrxO 2 solid solutions and core-shell nanostructured (Ce0.7Zr 0.3O2)x(Al2O3)1-x nanopowders. Sintering studies of the (ZrOx)x(Al2O 3)1-x core-shell nanopowders were performed to produce ZTA composites for structural applications. We were able to produce ZTA composites with 99 +% density and average grain sizes less than 200 nm by pressureless sintering < 1150 °C. Tetragonal zirconia was partially stabilized without added yttria. Phase transformation of zirconia (tetragonal to monoclinic) was observed by applied pressure. Additionally, nanopowders in the (ZnO)x(Al2O 3)1-x system were produced as potential transparent conducting oxides (TCOs) for display applications. Al2O3 doped ZnO nanopowders (ZnO rich region) were characterized suggesting Al 3+ ions incorporation into the interstitial sites of zincite. Spinel phase was found not only at 50 mole % ZnO in Al2O3 but also at 30 mole % ZnO in Al2O3.

Kim, Min

262

Preparation and characterization of hollow hydroxyapatite microspheres by spray drying method  

Microsoft Academic Search

Hollow hydroxyapatite (Ca10(PO4)6(OH)2) microspheres were prepared using a simple spray drying method. The incorporation of ammonium bicarbonate could produce carbon dioxide and ammonia gas bubbles during the spraying, and thus created a hollow inner structure in the resultant microspheres. The hollow microspheres prepared using different amounts of ammonium bicarbonate were also characterized. These microspheres were composed of nanoparticles with an

Ruixue Sun; Yupeng Lu; Kezheng Chen

2009-01-01

263

Optimization of Plasma Spray Process Using Statistical Methods  

NASA Astrophysics Data System (ADS)

The microstructure features of coatings produced by a plasma spray process are affected significantly by the process parameters such as powder size, spray gun nozzle size, total plasma gas flow, ratio of H2 + N2 over total gas flow, and so on. This article presents a study of the effects of these parameters on the microstructure (porosity, formation of crack, unmelted particle and oxide phase) of NiCrAlY coatings deposited by the Mettech Axial III™ System. A Taguchi array is used to design the spraying process parameters. The results of the microstructure evaluation are used to generate regression equations for the prediction of coating microstructure based on process parameters. The results predicted from the regression equations are in good agreement with the experimental results according to a confidence level of 0.95. Among the parameters examined, the powder size and the ratio of H2 + N2 over total gas flow rate are the most significant parameters affecting the occurrence of crack, porosity, unmelted particle and oxide. Within the range of the designed process parameters, lower powder size and higher ratio of H2 + N2 over total gas flow rate lead to less cracks, pores, unmelted particles but more oxides. Nozzle size has marginal influence on oxides which increase with nozzle size. Gas flow rate has no direct influence on any coating feature evaluated with the range of variation.

Gao, F.; Huang, X.; Liu, R.; Yang, Q.

2012-01-01

264

Nano spray drying: a novel method for preparing protein nanoparticles for protein therapy.  

PubMed

There has been an increasing interest in the development of protein nanotherapeutics for diseases such as cancer, diabetes and asthma. Spray drying with prior micro mixing is commonly used to obtain these powders. However, the separation and collection of protein nanoparticles with conventional spray dryer setups has been known to be extremely challenging due to its typical low collection efficiency for fine particles less than 2?m. To date, there has been no feasible approach to produce these protein nanoparticles in a single step and with high yield (>70%). In this study, we explored the feasibility of the novel Nano Spray Dryer B-90 (equipped with a vibrating mesh spray technology and an electrostatic particle collector) for the production of bovine serum albumin (BSA) nanoparticles. A statistical experimental design method (Taguchi method based on three levels, five variables L(18) orthogonal array robust design) was implemented to study the effect of and optimize the experimental conditions of: (1) spray mesh size, (2) BSA solution concentration, (3) surfactant concentration, (4) drying air flow rate and (5) inlet temperature on: (1) size and (2) morphology (axial ratio). Particle size and morphology were predominantly influenced by the spray mesh size and surfactant concentration, respectively. The drying air flow rate and inlet temperature had minimal impact. Optimized production of smooth spherical nanoparticles (median size: 460±10nm, axial ratio: 1.03±0.00, span 1.03±0.03, yield: 72±4%) was achieved using the 4?m spray mesh at BSA concentration of 0.1% (w/v), surfactant concentration of 0.05% (w/v), drying flow rate of 150L/min and inlet temperature of 120°C. The Nano Spray Dryer B-90 thus offers a new, simple and alternative approach for the production of protein nanoparticles suited for a variety of drug delivery applications. PMID:20951781

Lee, Sie Huey; Heng, Desmond; Ng, Wai Kiong; Chan, Hak-Kim; Tan, Reginald B H

2011-01-17

265

One-Dimensional Ablation with Pyrolysis Gas Flow Using a Full Newton's Method and Finite Control Volume Procedure  

NASA Technical Reports Server (NTRS)

The development and verification of a one-dimensional material thermal response code with ablation is presented. The implicit time integrator, control volume finite element spatial discretization, and Newton's method for nonlinear iteration on the entire system of residual equations have been implemented and verified for the thermochemical ablation of internally decomposing materials. This study is a continuation of the work presented in "One-Dimensional Ablation with Pyrolysis Gas Flow Using a Full Newton's Method and Finite Control Volume Procedure" (AIAA-2006-2910), which described the derivation, implementation, and verification of the constant density solid energy equation terms and boundary conditions. The present study extends the model to decomposing materials including decomposition kinetics, pyrolysis gas flow through the porous char layer, and a mixture (solid and gas) energy equation. Verification results are presented for the thermochemical ablation of a carbon-phenolic ablator which involves the solution of the entire system of governing equations.

Amar, Adam J.; Blackwell, Ben F.; Edwards, Jack R.

2007-01-01

266

Antibody immobilization using pneumatic spray: comparison with the avidin-biotin bridge immobilization method.  

PubMed

The formation of a thin antibody film on a glass surface using pneumatic spray was investigated as a potential immobilization technique for capturing pathogenic targets. Goat-Escherichia coli O157:H7 IgG films were made by pneumatic spray and compared against the avidin-biotin bridge immobilized films by assaying with green fluorescent protein (GFP) transformed E. coli O157:H7 cells and fluorescent reporter antibodies. Functionality, stability, and immobilization of the films were tested. The pneumatic spray films had lower fluorescence intensity values than the avidin-biotin bridge films but resulted in similar detection for E. coli O157:H7 at 10(5)-10(7)cells/ml sample concentrations with no detection of non-E. coli O157:H7 strains. Both methods also resulted in similar percent capture efficiencies. The results demonstrated that immobilization of antibody via pneumatic spray did not render the antibody non-functional and produced stable antibody films. The amount of time necessary for immobilization of the antibody was reduced significantly from 24h for the avidin-biotin bridge to 7 min using the pneumatic spray technique, with additional benefits of greatly reduced use of materials and chemicals. The pneumatic spray technique promises to be an alternative for the immobilization of antibodies on glass slides for capturing pathogenic targets and use in biosensor type devices. PMID:22955211

Figueroa, Jhon; Magaña, Sonia; Lim, Daniel V; Schlaf, Rudy

2012-12-14

267

Method and system including a double rotary kiln pyrolysis or gasification of waste material  

DOEpatents

A method is described for destructively distilling an organic material in particulate form wherein the particulates are introduced through an inlet into one end of an inner rotating kiln ganged to and coaxial with an outer rotating kiln. The inner and outer kilns define a cylindrical annular space with the inlet being positioned in registry with the axis of rotation of the ganged kilns. During operation, the temperature of the wall of the inner rotary kiln at the inlet is not less than about 500 C to heat the particulate material to a temperature in the range of from about 200 C to about 900 C in a pyrolyzing atmosphere to reduce the particulate material as it moves from the one end toward the other end. The reduced particulates including char are transferred to the annular space between the inner and the outer rotating kilns near the other end of the inner rotating kiln and moved longitudinally in the annular space from near the other end toward the one end in the presence of oxygen to combust the char at an elevated temperature to produce a waste material including ash. Also, heat is provided which is transferred to the inner kiln. The waste material including ash leaves the outer rotating kiln near the one end and the pyrolysis vapor leaves through the particulate material inlet. 5 figs.

McIntosh, M.J.; Arzoumanidis, G.G.

1997-09-02

268

Method and system including a double rotary kiln pyrolysis or gasification of waste material  

DOEpatents

A method of destructively distilling an organic material in particulate form wherein the particulates are introduced through an inlet into one end of an inner rotating kiln ganged to and coaxial with an outer rotating kiln. The inner and outer kilns define a cylindrical annular space with the inlet being positioned in registry with the axis of rotation of the ganged kilns. During operation, the temperature of the wall of the inner rotary kiln at the inlet is not less than about 500.degree. C. to heat the particulate material to a temperature in the range of from about 200.degree. C. to about 900.degree. C. in a pyrolyzing atmosphere to reduce the particulate material as it moves from the one end toward the other end. The reduced particulates including char are transferred to the annular space between the inner and the outer rotating kilns near the other end of the inner rotating kiln and moved longitudinally in the annular space from near the other end toward the one end in the presence of oxygen to combust the char at an elevated temperature to produce a waste material including ash. Also, heat is provided which is transferred to the inner kiln. The waste material including ash leaves the outer rotating kiln near the one end and the pyrolysis vapor leaves through the particulate material inlet.

McIntosh, Michael J. (Bolingbrook, IL) [Bolingbrook, IL; Arzoumanidis, Gregory G. (Naperville, IL) [Naperville, IL

1997-01-01

269

Monte Carlo Method for Predicting a Physically Based Drop Size Distribution Evolution of a Spray  

NASA Astrophysics Data System (ADS)

We report in this paper a method for predicting the evolution of a physically based drop size distribution of a spray, by coupling the Maximum Entropy Formalism and the Monte Carlo scheme. Using the discrete or continuous population balance equation, a Mass Flow Algorithm is formulated taking into account interactions between droplets via coalescence. After deriving a kernel for coalescence, we solve the time dependent drop size distribution equation using a Monte Carlo method. We apply the method to the spray of a new print-head known as a Spray On Demand (SOD) device; the process exploits ultrasonic spray generation via a Faraday instability where the fluid/structure interaction causing the instability is described by a modified Hamilton's principle. This has led to a physically-based approach for predicting the initial drop size distribution within the framework of the Maximum Entropy Formalism (MEF): a three-parameter generalized Gamma distribution is chosen by using conservation of mass and energy. The calculation of the drop size distribution evolution by Monte Carlo method shows the effect of spray droplets coalescence both on the number-based or volume-based drop size distributions.

Tembely, Moussa; Lécot, Christian; Soucemarianadin, Arthur

2010-03-01

270

In Vitro Evaluation of Dimensional Stability of Alginate Impressions after Disinfection by Spray and Immersion Methods  

PubMed Central

Background and aims The most common method for alginate impression disinfection is spraying it with disinfecting agents, but some studies have shown that these impressions can be immersed, too. The aim of this study was to evaluate the dimensional stability of alginate impressions following disinfecting by spray and immersion methods. Materials and methods Four common disinfecting agents (Sodium Hypochlorite, Micro 10, Glutaraldehyde and De-conex) were selected and the impressions (n=108) were divided into four groups (n=24) and eight subgroups (n=12) for disinfecting by any of the four above-mentioned agents by spray or immersion methods. The control group (n=12) was not disinfected. Then the impressions were poured by type III Dental Stone Plaster in a standard method. The results were ana-lyzed by descriptive methods (mean and standard deviation), t-test, two-way analysis of variance (ANOVA) and Duncan test, using SPSS 14.0 software for windows. Results The mean changes of length and height were significant between the various groups and disinfecting methods. Regarding the length, the greatest and the least amounts were related to Deconex and Micro 10 in the immersion method, respectively. Regarding height, the greatest and the least amounts were related to Glutaraldehyde and Deconex in the im-mersion method, respectively. Conclusion Disinfecting alginate impressions by Sodium Hypochlorite, Deconex and Glutaraldehyde by immersion method is not recommended and it is better to disinfect alginate impressions by spraying of Micro 10, Sodium Hypochlorite, Glutaraldehyde and immersion in Micro 10.

Hamedi Rad, Fahimeh; Ghaffari, Tahereh; Safavi, Sayed Hamed

2010-01-01

271

Sealing HVOF Thermally Sprayed WC-CoCr Coatings by Sol-Gel Methods  

NASA Astrophysics Data System (ADS)

The offshore industry faces challenges with corrosion resistance in hydraulic cylinders used in marine environments. Thermal spray coating appears to be a promising technique for replacing electroplated coating in many applications, but the performance of thermal spray coatings in highly corrosive environments must be improved. In the present work, a new sealing method for HVOF WC-CoCr coatings for their application on hydraulic cylinders for marine environments has been tested. The method consists of applying sol-gel solution that can penetrate, fill, and thus seal the pores and cracks in the coating. The sealed coatings have been tested with and without posttreatment and compared with as-sprayed coatings. Open-circuit potential (OCP) and tribocorrosion tests in 3.4% NaCl were performed to evaluate the performance of the sealing method. Both tests showed that the sealed coatings had the best performance.

Armada, S.; Tilset, B. G.; Pilz, M.; Liltvedt, R.; Bratland, H.; Espallargas, N.

2011-06-01

272

Measurement of the Young's Modulus of Thermal Spray Coatings by Means of Several Methods  

NASA Astrophysics Data System (ADS)

Thermally sprayed coatings are usually defined by their hardness, porosity, roughness, and wear resistance. Even though the Young's modulus is an essential property, which describes the mechanical behavior of the coated components during their use, only few efforts have been made in the past to determine this property. The most common measurement methods of the Young's modulus of thermally sprayed coatings are tensile tests, bending tests, and nanoindentations. During the tensile and bending tests a sliding of the splats can occur due to the laminar structure of the thermally sprayed coatings, influencing the measurement value. When using the nanoindentation test, only the elastic behavior of some splats can be determined because of a minimal measuring volume. However, the Young's modulus of thermally sprayed coatings can also be determined by means of a resonant method, called impulse excitation technique. In this paper, the values of the Young's moduli of thermally sprayed coatings, measured by several methods, are compared with each other and correlated to the microstructure of the coatings, investigated by means of scanning electron microscopy.

Tillmann, W.; Selvadurai, U.; Luo, W.

2013-03-01

273

Adhesive and cohesive properties by indentation method of plasma-sprayed hydroxyapatite coatings  

NASA Astrophysics Data System (ADS)

Adhesive and cohesive properties of the plasma-sprayed hydroxyapatite (HA) coatings, deposited on Ti-6Al-4V substrates by varying the plasma power level and spray distance (SD), were evaluated by an indentation method. The crystallinity and the porosity decreased with increasing both of these two parameters. The microhardness value, Young's modulus ( E) and coating fracture toughness ( KC) were found to increase with a combinational increase in spray power and SD. The Knoop and Vickers indentation methods were used to estimate E and KC, respectively. The critical point at which no crack appears at the interface was determined by the interface indentation test. This was used to define the apparent interfacial toughness ( KCa) which is representative of the crack initiation resistance of the interface. It was found that KCa reaches to a maximum at a medium increase in both spray power and SD, while other mechanical properties of the coatings reaches to the highest value with further increase in these two plasma parameters. The tensile adhesion strength of the coatings, measure by the standard adhesion test, ISO 13779-4, was shown to alter in the same manner with KCa results. It was deduced that a combinational increase in spray power and SD which leads to a higher mechanical properties in the coatings, does not necessarily tends to a better mechanical properties at the interface.

Mohammadi, Z.; Ziaei-Moayyed, A. A.; Mesgar, A. Sheikh-Mehdi

2007-03-01

274

Methods for detecting the mobility of trace elements during medium-temperature pyrolysis  

USGS Publications Warehouse

The mobility (volatility) of trace elements in coal during pyrolysis has been studied for distances of up to 40 cm between the coal and the trace element collector, which was graphite or a baffled solvent trap. Nineteen elements not previously recorded as mobile were detected. ?? 1983.

Shiley, R. H.; Konopka, K. L.; Cahill, R. A.; Hinckley, C. C.; Smith, G. V.; Twardowska, H.; Saporoschenko, M.

1983-01-01

275

Proton NMR thermal scanning methods for the study of oil shale pyrolysis  

Microsoft Academic Search

Dynamic experimental techniques by which non-equilibrium states of a system can be observed during thermally induced transformations allow the kinetics of pyrolysis mechanisms to be directly studied. This paper reports on the novel use of simple low resolution Proton nuclear magnetic resonance (¹HNMR) measurements as a reaction time probe to monitor the state of oil shales during heating from room

L. J. Lynch; D. S. Webster

1983-01-01

276

Confined-pyrolysis as an experimental method for hydrothermal organic synthesis  

NASA Astrophysics Data System (ADS)

A closed pyrolysis system has been developed as a tool for studying the reactions of organic compounds under extreme hydrothermal conditions. Small high pressure stainless steel vessels in which the ratio of sediment or sample to water has been adjusted to eliminate the headspace at peak experimental conditions confines the organic components to the bulk solid matrix and eliminates the partitioning of the organic compounds away from the inorganic components during the experiment. Confined pyrolysis experiments were performed to simulate thermally driven catagenetic changes in sedimentary organic matter using a solids to water ratio of 3.4 to 1. The extent of alteration was measured by monitoring the steroid and triterpenoid biomarkers and polycyclic aromatic hydrocarbon distributions. These pyrolysis experiments duplicated the hydrothermal transformations observed in nature. Molecular probe experiments using alkadienes, alkenes and alkanes in H2O and D2O elucidated the isomerization and hydrogenation reactions of aliphatic compounds and the competing oxidative reactions occurring under hydrothermal conditions. This confined pyrolysis technique is being applied to test experiments on organic synthesis of relevance to chemical evolution for the origin of life.

Leif, Roald N.; Simoneit, Bernd R. T.

1995-10-01

277

Waste pyrolysis - Alternative fuel source  

Microsoft Academic Search

Four means for producing alternative fuel sources via waste pyrolysis are considered. In the first, low-Btu gas is produced by waste pyrolysis in a refractory-lined rotary kiln. The second is based on solid waste passing through a gasifier, and then through stages of drying, pyrolysis, and combustion. This also yields a low-Btu gas. The third method produces a medium-Btu gas

L. M. Pruce

1978-01-01

278

Effect of gas flow swirling on coating deposition by the cold gas-dynamic spray method  

NASA Astrophysics Data System (ADS)

The effect of gas flow swirling on the process of coating deposition onto a target by the cold gas-dynamic spray method is studied experimentally and numerically. Flow swirling is found to change the gas flow field and to reduce the gas flow rate under typical conditions of cold gas-dynamic spray. In a non-swirled flow, the shape of the deposited spot is similar to a sharp cone. In contrast, the deposited spot in a swirled flow is shaped as a crater without particles at the center of this crater. It is found that this effect is caused by centrifugal forces acting on particles in a swirled gas flow.

Kiselev, S. P.; Kiselev, V. P.; Zaikovskii, V. N.

2012-03-01

279

Characterization of polycyclic aromatic hydrocarbons (PAHs) on lime spray dryer (LSD) ash using different extraction methods  

Microsoft Academic Search

In this study, traditional Soxhlet, automatic Soxhlet and ultrasonic extraction techniques were employed to determine the speciation and concentration of polycyclic aromatic hydrocarbons (PAHs) on lime spray dryer (LSD) ash samples collected from the baghouse of a spreader stoker boiler. To test the efficiencies of different extraction methods, LSD ash samples were doped with a mixture of 16 US EPA

Ping Sun; Linda K. Weavers; Panuwat Taerakul; Harold W. Walker

2006-01-01

280

Spray atomization and combustion  

NASA Technical Reports Server (NTRS)

New theoretical and experimental methods for studying sprays are reviewed. Common methods to analyze dilute sprays are described and used to interpret recent measurements of the structure of dilute sprays and related dispersed turbulent jets. Particle-laden jets, nonevaporating, evaporating, and combusting sprays, and noncondensing and condensing bubbly jets are examined and used to initially evaluate current analytical methods for a wide range of conditions. Dense sprays are briefly discussed.

Faeth, G. M.

1986-01-01

281

Application of scalar Monte Carlo probability density function method for turbulent spray flames  

SciTech Connect

The objective of the present work is twofold: (1) extend the coupled Monte Carlo probability density function (PDF)/computational fluid dynamics (CFD) computations to the modeling of turbulent spray flames, and (2) extend the PDF/SPRAY/CFD module to parallel computing in order to facilitate large-scale combustor computations. In this approach, the mean gas phase velocity and turbulence fields are determined from a standard turbulence model, the joint composition of species and enthalpy from the solution of a modeled PDF transport equation, and a Lagrangian-based dilute spray model is used for the liquid-phase representation. The PDF transport equation is solved by a Monte Carlo method, and the mean gas phase velocity and turbulence fields together with the liquid phase equations are solved by existing state-of-the-art numerical representations. The application of the method to both open as well as confined axisymmetric swirl-stabilized spray flames shows good agreement with the measured data. Preliminary estimates indicate that it is well within reach of today`s modern parallel computer to do a realistic gas turbine combustor simulation within a reasonable turnaround time. The article provides complete details of the overall algorithm, parallelization, and other numerical issues related to coupling between the three solvers.

Raju, M.S. [Nyma, Inc., Brook Park, OH (United States)

1996-12-01

282

Investigation of the spray characteristics for a secondary fuel injection nozzle using a digital image processing method  

NASA Astrophysics Data System (ADS)

There are many ways to reduce diesel engine exhaust emissions. However, NOx emission is difficult to reduce because the hydrocarbon (HC) concentration in a diesel engine is not sufficient for NOx conversion. Therefore, in order to create stoichiometric conditions in the De-NOx catalyst, a secondary injection system is designed to inject liquid HC into the exhaust pipe. The atomization and distribution characteristics of the HC injected from a secondary injector are key technologies to obtain a high NOx conversion because inhomogeneous droplets of injected HC cause not only high fuel consumption but also deterioration of NOx emission. This paper describes the spray characteristics of a secondary injector including the spray angle, penetration length and breakup behaviour of the spray to optimize the reduction rate of the NOx catalyst. In this study, various optical diagnostics were applied to investigate these spray characteristics, the atomization mechanism and spray developing process. The visualization and image processing method for the spray pulsation were developed by high speed photography. The influence of the fuel supply pressure on the spray behaviour and a more detailed spray developing process have been analysed experimentally using image processing. Finally, the experimental results were used to correlate the spray structure to the injection system performance and to provide a design guide for a secondary injector nozzle.

Jeong, Haeyoung; Lee, Kihyung; Ikeda, Yuji

2007-05-01

283

The feasibility study of hot cell decontamination by the PFC spray method  

SciTech Connect

The characteristics of per-fluorocarbon compounds (PFC) are colorless, non-toxic, easily vaporized and nonflammable. Also, some of them are liquids of a high density, low surface tension, low latent heat and low specific heat. These particular chemical and physical properties of fluoro-organic compounds permit their use in very different fields such as electronics, medicine, tribology, nuclear and material science. The Sonatol process was developed under a contract with the DOE. The Sonatol process uses an ultrasonic agitation in a PFC solution that contains a fluorinated surfactant to remove radioactive particles from surfaces. Filtering the suspended particles allows the solutions to be reused indefinitely. They applied the Sonatol process to the decontamination of a heterogeneous legacy Pu-238 waste that exhibited an excessive hydrogen gas generation, which prevents a transportation of such a waste to a Waste Isolation Pilot Plant. Korea Atomic Energy Research Institute (KAERI) is developing dry decontamination technologies applicable to a decontamination of a highly radioactive area loosely contaminated with radioactive particles. This contamination has occurred as a result of an examination of a post-irradiated material or the development of the DUPIC process. The dry decontamination technologies developed are the carbon dioxide pellet spray method and the PFC spray method. As a part of the project, PFC ultrasonic decontamination technology was developed in 2004. The PFC spray decontamination method which is based on the test results of the PFC ultrasonic method has been under development since 2005. The developed PFC spray decontamination equipment consists of four modules (spray, collection, filtration and distillation). Vacuum cup of the collection module gathers the contaminated PFC solution, then the solution is moved to the filtration module and it is recycled. After a multiple recycling of the spent PFC solution, it is purified in the distillation module. A performance test on each module was executed and the results have been reported. A combined test of the four modules, however, has not been performed as yet. The main objective of the present study is to demonstrate the feasibility of the full PFC spray decontamination process. Decontamination of the inside of the IMEF hot cell by the PFC spray method was also performed. PFC spray decontamination process was demonstrated by using a surrogate wall contaminated with Eu{sub 2}O{sub 3} powder. The spray pressure was 41 kgf/cm{sup 2}, the orifice diameter was 0.2 mm and the spray velocity was 0.2 L/min. And, the decontaminated area was 100 cm{sup 2}. From previous test results, we found that the decontamination factor of the PFC spray method was in the range from 9.6 to 62.4. When the decontamination efficiency of Co-60 was high, then the decontamination efficiency of Cs-137 was also high. As the surface roughness of the specimen increased, the PFC spray decontamination efficiency decreased. Inferring from the previous results, the surface of the surrogate wall was cleaned by the PFC spray method. The vacuum cup of the collection module operated well and gathered more than 99 % of the PFC solution. Also, filtration and distillation modules operated well. All the filtered PFC solution flowed to the storage chamber where some of the PFC solution was distilled. The coolant of the distillation module was a dry ice. And, the recycled solution was transferred to the spray module by a high pressure pump. To evaluate the PFC spray decontamination efficiency, a smear device was fabricated and operated by a manipulator. Before and after decontamination, a smear test was performed. The tested area was 100 cm{sup 2} and the radioactivity was estimated indirectly by measuring the radioactivity of the filter paper. The average decontamination factor was in the range between 10 and 15. One application time was 2 minutes. The sprayed PFC solution was collected by the vacuum cup and it was stored in the collection equipment. After the termination of the decontamination test, th

Hui-Jun Won; Chong-Hun Jung; Jei-Kwon Moon [Korea Atomic Energy Research Institute, 1045 Daedeokdaero, Yuseong-Gu, Daejeon, 305-353 (Korea, Republic of)

2008-01-15

284

On-line mass spectrometric methods for the determination of the primary products of fast pyrolysis of carbohydrates and for their gas-phase manipulation.  

PubMed

Mass spectrometric methodology was developed for the determination and manipulation of the primary products of fast pyrolysis of carbohydrates. To determine the true primary pyrolysis products, a very fast heating pyroprobe was coupled to a linear quadrupole ion trap mass spectrometer through a custom-built adaptor. A home-built flow tube that simulates pyrolysis reactor conditions was used to examine the secondary reactions of the primary products. Depending on the experiment, the pyrolysis products were either evaporated and quenched or allowed to react for a period of time. The quenched products were ionized in an atmospheric pressure chemical ionization (APCI) source infused with one of two ionization reagents, chloroform or ammonium hydroxide, to aid in ionization. During APCI in negative ion mode, chloroform produces chloride anions that are known to readily add to carbohydrates with little bias and little to no fragmentation. On the other hand, in positive ion mode APCI, ammonium hydroxide forms ammonium adducts with carbohydrates with little to no fragmentation. The latter method ionizes compounds that are not readily ionized upon negative ion mode APCI, such as furan derivatives. Six model compounds were studied to verify the ability of the ionization methods to ionize known pyrolysis products: glycolaldehyde, hydroxyacetone, furfural, 5-hydroxymethylfurfural, levoglucosan, and cellobiosan. The method was then used to examine fast pyrolysis of cellobiose. The primary fast pyrolysis products were determined to consist of only a handful of compounds that quickly polymerize to form anhydro-oligosaccharides when allowed to react at high temperatures for an extended period of time. PMID:24098979

Hurt, Matthew R; Degenstein, John C; Gawecki, Piotr; Borton, David J; Vinueza, Nelson R; Yang, Linan; Agrawal, Rakesh; Delgass, W Nicholas; Ribeiro, Fabio H; Kenttämaa, Hilkka I

2013-11-19

285

Nanostructured PbO materials obtained in situ by spray solution technique for Li-ion batteries  

Microsoft Academic Search

This paper describes a systematic study of the effect of various spray pyrolysis parameters, such as temperature, solution concentration and solution flow rate on the morphology, crystallization process, crystal size, specific surface area and electrochemical performance of in situ prepared ?-PbO spherically agglomerated nano-structured powders. Different analytical methods such as XRD, SEM, TEM, BET gas sorption specific surface area measurements

K. Konstantinov; S. H. Ng; J. Z. Wang; G. X. Wang; D. Wexler; H. K. Liu

2006-01-01

286

Spray pyrolysis of MgO templates on Hastelloy C276 and 310-austenitic stainless steel substrates for Y Ba2Cu3O7 (YBCO) deposition by pulsed laser deposition  

NASA Astrophysics Data System (ADS)

MgO thin films were deposited on Hastelloy C276 (HC) and 310 austenitic stainless steel by the spray pyrolysis technique, using magnesium nitrate and magnesium acetate as precursors. Thermogravimetrical analysis of the decomposition of the precursors was used to provide a guideline temperature for the thin film deposition. It was suggested that an amorphous MgO thin film was deposited on both 310-stainless steel and Hastelloy C-276 when using low concentration of the magnesium nitrate precursor. Higher concentrations were needed to obtain (200) oriented MgO films on C276. However, 310-stainless steel was found to not be a suitable substrate for MgO thin film deposition due to surface instability. A (200) oriented MgO thin film was grown on Hastelloy C276 using a magnesium acetate precursor at a much lower concentration compared to the nitrate precursor. The characterization of the thin films was done using scanning electron microscopy, x-ray photoelectron spectroscopy, atomic force microscopy, x-ray diffraction 2?-scans, rocking curves (?-scans), and pole figure measurements. MgO was found to have a very weak in-plane texture.

Khateeb, Shadi Al; Button, T. W.; Abell, J. S.

2010-09-01

287

Effect of Ag doping on the transition temperature and critical current density of Hg 1- xTl xBa 2Ca 2Cu 3O 8+ ? films fabricated through spray pyrolysis  

NASA Astrophysics Data System (ADS)

The Ag doped Hg(Tl):1223 films have been synthesised by annealing Ba 2Ca 2.2Cu 3.3O z(Ag y); y= 0, 0.25, 0.5, 0.75, 1.0 precursors deposited by spray pyrolysis on single crystal MgO and ZrO 2 substrates, in controlled Hg-Tl vapour ambient in an evacuated sealed quartz tube at 860°C for 720 minutes. The transition temperature ( Tc), dc transport critical current density ( Jc) and microstructure of the films have been found sensitive to Ag content. The microstructural details as revealed through scanning electron microscopy exhibit the curious characteristics of the existence of spiral like growth feature which is found to deteriorate with increasing Ag concentration. The maximum Tc = 126 K of the as synthesized Ag doped film with Ag = 0.50 is nearly the same as the T c = 127 K of oxygen annealed Ag-free films, suggesting in itu oxygenation. The transition temperature has been found to decrease for higher Ag contents (0.50 < y < 1.00). The Jc has been observed to decrease steadily with increase in silver content, being highest (7.2 x 10 4 A/cm 2, 20 K) in Ag-free case. This decrease in Jc has been accounted for in term of formation of Ag(Hg) amalgam due to the reaction of Ag with Hg already present in the grain boundary region.

Singh, H. K.; Saxena, A. K.; Srivastava, O. N.

1997-02-01

288

Generation of functional structures by laser pyrolysis of polysilazane  

Microsoft Academic Search

The pyrolysis of polysilazanes by laser power represents an innovative technique for the generation of ceramic-like coatings and structures. The dissolved polysilazanes can be easily applied by painting techniques such as dipping or spraying. In the following pyrolysis the polysilazane layer transforms into an amorphous ceramic-like coating. The laser power is absorbed in the precursor layer, which leads to the

Hans-Joachim Krauss; Andreas Otto

2002-01-01

289

Tabletted polylactide microspheres prepared by a w/o emulsion-spray drying method.  

PubMed

An emulsification-spray drying technique is used to prepare poly(D,L-lactic acid) (PDLLA) microparticles loaded with a water soluble, non-steroidal anti-inflammatory drug (NSAID), sodium naproxen (NaNPX). The method involves the preparation of a w/o emulsion in which the water soluble drug is dissolved in the aqueous dispersed phase, while the polymer is dissolved in the organic continuous phase. As a comparison, microparticles were prepared by spraying a suspension of the drug into an organic solution of the polymer. The spray-dried particles were characterized using SEM, DSC, XRD and in vitro release tests. The spray-dried product was then compressed (direct compression) to obtain controlled release matrix tablets. All microparticles release NaNPX within 30 min. The matrix tablets release the drug in 8-10 h; the matrix tablets characterized by the presence of surfactant (due to the emulsion used to obtain the microparticles) have the highest release rate. PMID:11063418

Giunchedi, P; Gavini, E; Bonacucina, G; Palmieri, G F

2000-01-01

290

Determination of Pyrolysis Temperature for Charring Materials.  

National Technical Information Service (NTIS)

An energy and mass balanced method of determining the pyrolysis temperature is proposed. The concept is to find the pyrolysis temperature that consumes the same amount of energy to produce the same amount of mass when using the pyrolysis front model as wh...

A. Atreya H. R. Baum W. C. Park

2007-01-01

291

High temperature fatigue deformation behaviors of thermally sprayed steel measured with electronic speckle pattern interferometry method  

SciTech Connect

High temperature fatigue (R=0) damage and deformation behaviors of SUS304 steel thermally sprayed with Al{sub 2}O{sub 3}/NiCr coating were investigated using an electronic speckle pattern interferometry (ESPI) method. Surface cracks and delamination occurred after 1x10{sup 5} cycles test when {sigma}{sub max} was 202 MPa at 873 K. The lengths and number of cracks and delamination largely decreased when {sigma}{sub max} or temperature decreased to 115 MPa or 573 K, respectively. Strain values along cracks measured with the ESPI method were much larger than other areas due to crack opening under the tensile load. The positions of strain concentration zones on strain distribution figures by ESPI method were well corresponded to those of cracks on sprayed coatings. Strain values decreased largely where local delamination occurred.

Wang, Rongguang; Kido, Mitsuo

2003-07-14

292

Roughness-based monitoring of transparency and conductivity in boron-doped ZnO thin films prepared by spray pyrolysis  

SciTech Connect

Graphical abstract: Display Omitted Highlights: ? We report surface roughness dependent transparency and conductivity in ZnO films. ? The surface roughness with respected to boron doping concentrations is studied. ? Boron doped and pristine Zinc oxide thin films have showed ?95% transmittance. ? Increased carrier concentration of 9.21 × 10{sup 21} cm{sup ?3} revealed from Hall measurement. -- Abstract: Sprayed polycrystalline ZnO and boron-doped ZnO thin films composed of spherical grains of 25–32 nm in diameters are used in roughness measurement and further correlated with the transparency and the conductivity characteristics. The surface roughness is increased up to Zn{sub 0.98}B{sub 0.02}O and then declined at higher boron concentrations. The sprayed ZnO films revealed ?95% transmittance in the visible wavelength range, 1.956 × 10{sup ?4} ? cm electrical resistivity, 46 cm{sup 2}/V s Hall mobility and 9.21 × 10{sup 21} cm{sup ?3} charge carrier concentration. The X-ray photoelectron spectroscopy study has confirmed 0.15 eV binding energy change for Zn 2p{sub 3/2} when 2 at% boron content is mixed without altering electro-optical properties substantially. Finally, using soft modeling importance of these textured ZnO over non-textured films for enhancing the solar cells performance is explored.

Gaikwad, Rajendra S. [Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of) [Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of); Department of Physics, Yashwantrao Mohite College, Bharati Vidyapeeth Deemed University, Pune 411038, Maharashtra (India); Bhande, Sambhaji S. [Centre for Nanomaterials and Energy Devices, School of Physical Sciences, Swami Ramand Teerth Marathwada University, Nanded (India)] [Centre for Nanomaterials and Energy Devices, School of Physical Sciences, Swami Ramand Teerth Marathwada University, Nanded (India); Mane, Rajaram S., E-mail: rsmane_2000@yahoo.com [Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of); Inorganic Nanomaterials Laboratory, Department of Chemistry, Hanyang University, Seoul 133-791 (Korea, Republic of); Centre for Nanomaterials and Energy Devices, School of Physical Sciences, Swami Ramand Teerth Marathwada University, Nanded (India); Pawar, Bhagwat N. [Department of Physics, Yashwantrao Mohite College, Bharati Vidyapeeth Deemed University, Pune 411038, Maharashtra (India)] [Department of Physics, Yashwantrao Mohite College, Bharati Vidyapeeth Deemed University, Pune 411038, Maharashtra (India); Gaikwad, Sanjay L. [Centre for Nanomaterials and Energy Devices, School of Physical Sciences, Swami Ramand Teerth Marathwada University, Nanded (India)] [Centre for Nanomaterials and Energy Devices, School of Physical Sciences, Swami Ramand Teerth Marathwada University, Nanded (India); Han, Sung-Hwan [Inorganic Nanomaterials Laboratory, Department of Chemistry, Hanyang University, Seoul 133-791 (Korea, Republic of)] [Inorganic Nanomaterials Laboratory, Department of Chemistry, Hanyang University, Seoul 133-791 (Korea, Republic of); Joo, Oh-Shim, E-mail: jookat@kist.ac.kr [Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of)] [Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of)

2012-12-15

293

Heat Transfer Applications of Meshless Local Petrov-Galerkin (MLPG) Method during Plasma Spray  

Microsoft Academic Search

In this work, a compact computational formulation is established based on the truly meshless method MLPG, and is firstly used\\u000a to solve steady and transient heat conductions of the plasma spray. The unknown function of temperature distribution is approximated\\u000a by moving least square approximation functions. These approximants are constructed by using a weight function, a polynomial\\u000a basis and a set

S. C. Wu; H. O. Zhang; G. L. Wang; W. S. Xia

294

Structure and properties of aluminum coatings obtained by the cold gas-dynamic spraying method  

Microsoft Academic Search

Structure and properties of aluminum coatings deposited onto steel substrates by the cold gas-dynamic spraying (CGS) method\\u000a were examined. Aluminum CGS coatings fundamentally differ from their thermal counterparts as they enable the formation of\\u000a heavy-duty layers of metal particles on substrates at temperatures below 500 K. A dense, low-porosity coating is found to\\u000a form, tightly bound to the base metal.

L. I. Tushinsky; A. P. Alkhimov; V. F. Kosarev; A. V. Plokhov; N. S. Mochalina

2006-01-01

295

The Optical Properties of CdSe Quantum Dots by Using Spray-Atomization Method  

NASA Astrophysics Data System (ADS)

Cadmium Selenide (CdSe) quantum dots (QDs) is inorganic material by using spray-atomization method which is the novelty to find out the optical properties for the CdSe QDs. The Selenium (Se) precursor and Cadmium (Cd) precursor were prepared first. Se precursor by using sodium sulfite aqueous was mixed with selenium (Se) powder. For Cd precursor was used cadmium chloride (CdCI) as the Cd precursor. From previous research, CdSe QDs was obtained by using capping agent such as tri-n-octylphosphine oxide (TOPO) and trioctylphosphine (TOP). These capping agent are hazardous to environment and human. By using spray-atomization method it is more safe and economically. The photoluminescence (PL) was used to investigate the optical properties and to investigate the energy band gap from PL result. The field emission scanning electron microscopy (FESEM) was used to know the surface morphology of CdSe QDs. By PL result, the energy band gap was calculate and the comparison was investigate between the size of particle and the energy band gap. This important in this paper is to investigate the optical properties of CdSe QDs by using sprays-atomization method and to relate with the particle size.

Rosmani, C. H.; Abdullah, S.; Rusop, M.

2013-06-01

296

Fabrication of ordered bulk heterojunction organic photovoltaic cells using nanopatterning and electrohydrodynamic spray deposition methods.  

PubMed

Organic photovoltaic cells with an ordered heterojunction (OHJ) active layer are expected to show increased performance. In the study described here, OHJ cells were fabricated using a combination of nanoimprinting and electrohydrodynamic (EHD) spray deposition methods. After an electron donor material was nanoimprinted with a PDMS stamp (valley width: 230 nm, period: 590 nm) duplicated from a Si nanomold, an electron acceptor material was deposited onto the nanoimprinted donor layer using an EHD spray deposition method. The donor-acceptor interface layer was observed by obtaining cross-sectional images with a focused ion beam (FIB) microscope. The photocurrent generation performance of the OHJ cells was evaluated with the current density-voltage curve under air mass (AM) 1.5 conditions. It was found that the surface morphology of the electron acceptor layer affected the current and voltage outputs of the photovoltaic cells. When an electron acceptor layer with a smooth thin (250 nm above the valley of the electron donor layer) surface morphology was obtained, power conversion efficiency was as high as 0.55%. The electrohydrodynamic spray deposition method used to produce OHJ photovoltaic cells provides a means for the adoption of large area, high throughput processes. PMID:23138540

Park, Sung-Eun; Kim, Sehwan; Kim, Kangmin; Joe, Hang-Eun; Jung, Buyoung; Kim, Eunkyoung; Kim, Woochul; Min, Byung-Kwon; Hwang, Jungho

2012-12-21

297

Numerical Modeling of Spray Combustion with an Unstructured-Grid Method  

NASA Technical Reports Server (NTRS)

The present unstructured-grid method follows strictly the basic finite volume forms of the conservation laws of the governing equations for the entire flow domain. High-order spatially accurate formulation has been employed for the numerical solutions of the Navier-Stokes equations. A two-equation k-epsilon turbulence model is also incorporated in the unstructured-grid solver. The convergence of the resulted linear algebraic equation is accelerated with preconditioned Conjugate Gradient method. A statistical spray combustion model has been incorporated into the present unstructured-grid solver. In this model, spray is represented by discrete particles, rather than by continuous distributions. A finite number of computational particles are used to predict a sample of total population of particles. Particle trajectories are integrated using their momentum and motion equations and particles exchange mass, momentum and energy with the gas within the computational cell in which they are located. The interaction calculations are performed simultaneously and eliminate global iteration for the two-phase momentum exchange. A transient spray flame in a high pressure combustion chamber is predicted and then the solution of liquid-fuel combusting flow with a rotating cup atomizer is presented and compared with the experimental data. The major conclusion of this investigation is that the unstructured-grid method can be employed to study very complicated flow fields of turbulent spray combustion. Grid adaptation can be easily achieved in any flow domain such as droplet evaporation and combustion zone. Future applications of the present model can be found in the full three-dimensional study of flow fields of gas turbine and liquid propulsion engine combustion chambers with multi-injectors.

Shang, H. M.; Chen, Y. S.; Liaw, P.; Shih, M. H.; Wang, T. S.

1996-01-01

298

Method and Process Development of Advanced Atmospheric Plasma Spraying for Thermal Barrier Coatings  

NASA Astrophysics Data System (ADS)

Over the last few years, global economic growth has triggered a dramatic increase in the demand for resources, resulting in steady rise in prices for energy and raw materials. In the gas turbine manufacturing sector, process optimizations of cost-intensive production steps involve a heightened potential of savings and form the basis for securing future competitive advantages in the market. In this context, the atmospheric plasma spraying (APS) process for thermal barrier coatings (TBC) has been optimized. A constraint for the optimization of the APS coating process is the use of the existing coating equipment. Furthermore, the current coating quality and characteristics must not change so as to avoid new qualification and testing. Using experience in APS and empirically gained data, the process optimization plan included the variation of e.g. the plasma gas composition and flow-rate, the electrical power, the arrangement and angle of the powder injectors in relation to the plasma jet, the grain size distribution of the spray powder and the plasma torch movement procedures such as spray distance, offset and iteration. In particular, plasma properties (enthalpy, velocity and temperature), powder injection conditions (injection point, injection speed, grain size and distribution) and the coating lamination (coating pattern and spraying distance) are examined. The optimized process and resulting coating were compared to the current situation using several diagnostic methods. The improved process significantly reduces costs and achieves the requirement of comparable coating quality. Furthermore, a contribution was made towards better comprehension of the APS of ceramics and the definition of a better method for future process developments.

Mihm, Sebastian; Duda, Thomas; Gruner, Heiko; Thomas, Georg; Dzur, Birger

2012-06-01

299

Effect of boric acid on the properties of Li{sub 2}MnO{sub 3}·LiNi{sub 0.5}Mn{sub 0.5}O{sub 2} composite cathode powders prepared by large-scale spray pyrolysis with droplet classifier  

SciTech Connect

Graphical abstract: Display Omitted Highlights: ? Spherical shape Li{sub 2}MnO{sub 3}·LiNi{sub 0.5}Mn{sub 0.5}O{sub 2} composite cathode powders are prepared by large-scale spray pyrolysis with droplet classifier. ? Boric acid improves the morphological and electrochemical properties of the composite cathode powders. ? The discharge capacity of the composite cathode powders decreases from 217 to 196 mAh g{sup ?1} by the 30th cycle. -- Abstract: Spherically shaped 0.3Li{sub 2}MnO{sub 3}·0.7LiNi{sub 0.5}Mn{sub 0.5}O{sub 2} composite cathode powders with filled morphology and narrow size distribution are prepared by large-scale spray pyrolysis. A droplet classification reduces the standard deviation of the size distribution of the composite cathode powders. Addition of boric acid improves the morphological properties of the product powders by forming a lithium borate glass material with low melting temperature. The optimum amount of boric acid dissolved in the spray solution is 0.8 wt% of the composite powders. The powders prepared from the spray solution with 0.8 wt% boric acid have a mixed layered crystal structure comprising Li{sub 2}MnO{sub 3} and LiNi{sub 0.5}Mn{sub 0.5}O{sub 2} phases, thus forming a composite compound. The initial charge and discharge capacities of the composite cathode powders prepared from the 0.8 wt% boric acid spray solution are 297 and 217 mAh g{sup ?1}, respectively. The discharge capacity of the powders decreases from 217 to 196 mAh g{sup ?1} by the 30th cycle, in which the capacity retention is 90%.

Hong, Young Jun; Choi, Seung Ho; Sim, Chul Min; Lee, Jung-Kul [Department of Chemical Engineering, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701 (Korea, Republic of)] [Department of Chemical Engineering, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701 (Korea, Republic of); Kang, Yun Chan, E-mail: yckang@konkuk.ac.kr [Department of Chemical Engineering, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701 (Korea, Republic of)

2012-12-15

300

Numerical analysis of partially molten splat during thermal spray process using the finite element method  

NASA Astrophysics Data System (ADS)

A finite element method is used to simulate the deposition of the thermal spray coating process. A set of governing equations is solving by a volume of fluid method. For the solidification phenomenon, we use the specific heat method (SHM). We begin by comparing the present model with experimental and numerical model available in the literature. In this study, completely molten or semi-molten aluminum particle impacts a H13 tool steel substrate is considered. Next we investigate the effect of inclination of impact of a partially molten particle on flat substrate. It was found that the melting state of the particle has great effects on the morphologies of the splat.

Zirari, M.; Abdellah El-Hadj, A.; Bacha, N.

2010-03-01

301

Study of Surface Cleaning Methods and Pyrolysis Temperature on Nano-Structured Carbon Films using X-ray Photoelectron Spectroscopy  

SciTech Connect

Nanostructured carbon (ns-C) films fabricated by stabilization and pyrolysis of di-block copolymers are of interest for a variety of electrical/electronic applications due to their chemical inertness, high-temperature insensitivity, very high surface area, and tunable electrical resistivity over a wide range [Kulkarni et al., Synth. Met. 159, (2009) 177]. Because of their high porosity and associated high specific surface area, controlled surface cleaning studies are important for fabricating electronic devices from these films. In this study, quantification of surface composition and surface cleaning studies on ns-C films synthesized by carbonization of di-block copolymers of polyacrylonitrile-b-poly(n-butyl acrylate) (PAN-b-PBA) at two different temperatures were carried out. X-ray photoelectron spectroscopy was used for elemental analysis and to determine the efficacy of various surface cleaning methods for ns-C films and to examine the polymer residues in the films. The in-situ surface cleaning methods included: HF vapor treatment, vacuum annealing, and exposure to UV-ozone. Quantitative analysis of high-resolution XPS scans showed 11 at. % of nitrogen present in the films pyrolyzed at 600 °C, suggesting incomplete denitrogenation of the copolymer films. The nitrogen atomic concentration reduced significantly for films pyrolyzed at 900 °C confirming extensive denitrogenation at that temperature. Furthermore, quantitative analysis of nitrogen sub-peaks indicated higher loss of nitrogen atoms residing at the edge of graphitic clusters relative to that of nitrogen atoms within the graphitic cluster, suggesting higher graphitization with increasing pyrolysis temperature. Of the surface cleaning methods investigated, in-situ annealing of the films at 300 °C for 40 min was found to be the most efficacious in removing adventitious carbon and oxygen impurities from the surface.

Kerber, Pranita B.; Porter, Lisa M.; McCullough, L. A.; Kowalewski, Tomasz; Engelhard, Mark H.; Baer, Donald R.

2012-10-12

302

Study of surface cleaning methods and pyrolysis temperatures on nanostructured carbon films using x-ray photoelectron spectroscopy  

SciTech Connect

Nanostructured carbon (ns-C) films fabricated by stabilization and pyrolysis of diblock copolymers are of interest for a variety of electrical/electronic applications due to their chemical inertness, high-temperature insensitivity, very high surface area, and tunable electrical resistivity over a wide range [Kulkarni et al., Synth. Met. 159, 177 (2009)]. Because of their high porosity and associated high specific surface area, controlled surface cleaning studies are important for fabricating electronic devices from these films. In this study, quantification of surface composition and surface cleaning studies on ns-C films synthesized by carbonization of diblock copolymers of polyacrylonitrile-b-poly(n-butyl acrylate) at two different temperatures were carried out. X-ray photoelectron spectroscopy was used for elemental analysis and to determine the efficacy of various surface cleaning methods for ns-C films and to examine the polymer residues in the films. The in-situ surface cleaning methods included HF vapor treatment, vacuum annealing, and exposure to UV-ozone. Quantitative analysis of high-resolution XPS scans showed 11 at. % nitrogen was present in the films pyrolyzed at 600 Degree-Sign C, suggesting incomplete denitrogenation of the copolymer films. The nitrogen atomic concentration decreased significantly for films pyrolyzed at 900 Degree-Sign C confirming extensive denitrogenation at that temperature. Furthermore, quantitative analysis of nitrogen subpeaks indicated higher loss of nitrogen atoms residing at the edge of graphitic clusters relative to that of nitrogen atoms within the graphitic clusters, suggesting higher graphitization with increasing pyrolysis temperature. Of the surface cleaning methods investigated, in-situ annealing of the films at 300 Degree-Sign C for 40 min was found to be the most efficacious in removing adventitious carbon and oxygen impurities from the surface.

Kerber, Pranita; Porter, Lisa M.; McCullough, Lynne A.; Kowalewski, Tomasz; Engelhard, Mark; Baer, Donald [Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213 (United States); Chemistry Department, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213 (United States); Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352 (United States)

2012-11-15

303

Synthesis of nano-sized Co 3 O 4 powder by spray conversion method for anode material of lithium battery  

Microsoft Academic Search

A nano-sized Co3O4 powder was prepared using a spray conversion method that could be applied for mass production. The spray-conversion process\\u000a consisted of spray drying of a metallic liquid solution, a calcination treatment, and a ball milling process. The calcined\\u000a Co3O4 powder consisted of agglomerated spherical clusters with nano-sized particles. After milling for 24 h, agglomerated powders\\u000a were fragmented into

Seong-Hyeon Hong; Jong-Soo Bae; Hyo-Jun Ahn

2008-01-01

304

Molecular characterization and comparison of shale oils generated by different pyrolysis methods using FT-ICR mass spectrometry  

USGS Publications Warehouse

Fourier transform ion cyclotron resonance mass spectrometry (FT ICR-MS) was applied in the analysis of shale oils generated using two different pyrolysis systems under laboratory conditions meant to simulate surface and in situ oil shale retorting. Significant variations were observed in the shale oils, particularly the degree of conjugation of the constituent molecules. Comparison of FT ICR-MS results to standard oil characterization methods (API gravity, SARA fractionation, gas chromatography-flame ionization detection) indicated correspondence between the average Double Bond Equivalence (DBE) and asphaltene content. The results show that, based on the average DBE values and DBE distributions of the shale oils examined, highly conjugated species are enriched in samples produced under low pressure, high temperature conditions and in the presence of water.

Jin, J. M.; Kim, S.; Birdwell, J. E.

2011-01-01

305

Recent advances in nanoparticle preparation by spray and micro-emulsion methods.  

PubMed

Micro- and nano-sized metal, semiconductor, pharmaceutical, and simple or complex ceramic particles have numerous applications in the development of sensors, thermal barrier coatings, catalysts, pigments, drugs, etc. The challenges include controlling the particle size, size distribution, particle crystallinity, morphology and shape, being able to use the nanoparticles for a given purpose, and to produce them from a variety of precursors. There are several methods to produce nanoparticles, each suitable for a range of applications. In this article, two methods that are receiving increasing attention are considered: spray and microemulsion methods. Spray techniques are single-step methods of producing a broad spectrum of simple to multicomponent functional micro and nanoparticles and quantum dots. Microemulsion is a wet chemistry method. A micro-emulsion system consists of aqueous domains, called reverse micelles, dispersed in a continuous oil phase. In this article, the above mentioned methods of nanoparticle production are introduced and recent advances, research directions and challenges, and the pertinent patents are reviewed and discussed. PMID:19519594

Eslamian, Morteza; Shekarriz, Marzieh

2009-01-01

306

Cetirizine dihydrochloride loaded microparticles design using ionotropic cross-linked chitosan nanoparticles by spray-drying method  

Microsoft Academic Search

To control the release rate and mask the bitter taste, cetirizine dihydrochloride (CedH) was entrapped within chitosan nanoparticles\\u000a (CS-NPs) using an ionotropic gelation process, followed by microencapsulation to produce CS matrix microparticles using a\\u000a spray-drying method. The aqueous colloidal CS-NPs dispersions with a drug encapsulation efficiency (EE) of <15%, were then\\u000a spray dried to produce a powdered nanoparticles-in-microparticles system with

Feng-Qian Li; Rui-Rui Ji; Xu Chen; Ben-Ming You; Yong-Hua Pan; Jia-Can Su

2010-01-01

307

Chemical spray pyrolysis of Tl-Ba-Ca-Cu-O high-T(sub c) superconductors for high-field bitter magnets  

NASA Technical Reports Server (NTRS)

The deposition of Tl-Ba-Ca-Cu-O thick films by spray pyrolyzing a Ba-Ca-Cu-O precursor film and diffusing thallium into the film to form the superconducting phase is examined. This approach was taken to reduce exposure to thallium and its health and safety hazards. The Tl-Ba-Ca-Cu-O system was selected because it has very attractive features which make it appealing to device and manufacturing engineering. Tl-Ba-Ca-Cu-O will accommodate a number of superconducting phases. This attribute makes it very forgiving to stoichiometric fluctuations in the bulk and film. It has excellent thermal and chemical stability, and appears to be relatively insensitive to chemical impurities. Oxygen is tightly bound into the systems, consequently there is no orthorhombic (conductor) to tetragonal (insulator) transition which would affect a component's lifetime. More significantly, the thallium based superconductors appear to have harder magnetic properties than the other high-Tc oxide ceramics. Estimates using magnetoresistance measurements indicate that at 77 K Tl2Ba2CaCu2O10 will have an upper critical field, H(sub c2) fo 26 Tesla for applied fields parallel to the c-axis and approximately 1000 Tesla for fields oriented in the a-b plane. Results to date have shown that superconducting films can be reproducibly deposited on 100 oriented MgO substrates. One film had a zero resistance temperature of 111.5 K. Furthermore, x ray diffraction analysis of the films showed preferential c-axis orientation parallel to the plane of the substrate. These results have now made it possible to consider the manufacture of a superconducting tape wire which can be configured into a topology useful for high-field magnet designs. The research which leads to the preparation of these films and plans for further development are reviewed.

Derochemont, L. Pierre; Zhang, John G.; Squillante, Michael R.; Hermann, A. M.; Duan, H. M.; Andrews, Robert J.; Kelliher, Warren C.

1991-01-01

308

Gas phase temperature measurements in the liquid and particle regime of a flame spray pyrolysis process using O2-based pure rotational coherent anti-Stokes Raman scattering.  

PubMed

For the production of oxide nanoparticles at a commercial scale, flame spray processes are frequently used where mostly oxygen is fed to the flame if high combustion temperatures and thus small primary particle sizes are desired. To improve the understanding of these complex processes in situ, noninvasive optical measurement techniques were applied to characterize the extremely turbulent and unsteady combustion field at those positions where the particles are formed from precursor containing organic solvent droplets. This particle-forming regime was identified by laser-induced breakdown detection. The gas phase temperatures in the surrounding of droplets and particles were measured with O(2)-based pure rotational coherent anti-Stokes Raman scattering (CARS). Pure rotational CARS measurements benefit from a polarization filtering technique that is essential in particle and droplet environments for acquiring CARS spectra suitable for temperature fitting. Due to different signal disturbing processes only the minority of the collected signals could be used for temperature evaluation. The selection of these suitable signals is one of the major problems to be solved for a reliable evaluation process. Applying these filtering and signal selection steps temperature measurements have successfully been conducted. Time-resolved, single-pulse measurements exhibit temperatures between near-room and combustion temperatures due to the strongly fluctuating and flickering behavior of the particle-generating flame. The mean flame temperatures determined from the single-pulse data are decreasing with increasing particle concentrations. They indicate the dissipation of large amounts of energy from the surrounding gas phase in the presence of particles. PMID:22945152

Engel, Sascha R; Koegler, Andreas F; Gao, Yi; Kilian, Daniel; Voigt, Michael; Seeger, Thomas; Peukert, Wolfgang; Leipertz, Alfred

2012-09-01

309

A novel preparation method for drug nanocrystals and characterization by ultrasonic spray-assisted electrostatic adsorption  

PubMed Central

Purpose The purpose of this study was to develop a novel and continuous method for preparing a nanosized particle of drug crystals and to characterize its properties. Materials and methods A new apparatus was introduced to crystallize nanosized drug crystals of amitriptyline hydrochloride as a model drug. The samples were prepared in the pure state by ultrasonic spray, and elaborated deposition was completed via electrostatic adsorption. Scanning electron microscopy, X-ray powder diffraction, and atomic force microscopy were used to characterize the size of the particles; this was subsequently followed by differential scanning calorimetry. Results and discussion Nanoparticles of drug crystals were successfully prepared. The size of the drug crystals ranged from 20 nm to 400 nm; the particle size of amitriptyline hydrochloride was approximately 71 nm. The particles were spherical and rectangular in shape. Moreover, the melting point of the nanoparticles decreased from 198.2°C to 196.3°C when compared to raw particle crystals. Furthermore, the agglomeration effect was also attenuated as a result of electrostatic repulsion among each particle when absorbed, and depositing on the inner wall of the gathering unit occurred under the electrostatic effect. Conclusion Ultrasonic spray-assisted electrostatic adsorption is a very effective and continuous method to produce drug nanocrystals. This method can be applied to poorly water-soluble drugs, and it can also be a very effective alternative for industrial production. Once the working parameters are given, drug nanocrystals will be produced continuously.

Gao, Bing; Wang, Jun; Wang, Dunju; Zhu, Ziqiang; Qiao, Zhiqiang; Yang, Guangcheng; Nie, Fude

2013-01-01

310

ANALYSIS OF A FAN-SHAPED SPRAY USING 2D ILIDS METHOD  

Microsoft Academic Search

KEYWORDS - Fan-shaped spray, ILIDS, Droplet size, Droplet velocity, Droplet distribution ABSTRACT - DI (direct injection) systems have been studied to improve thermal efficiency of gasoline engines. The analysis of spray behavior is important to examine the combustion characteristics of DI gasoline engines because fuel-air mixture formation is controlled by spray characteristics and gas motion. In this study, the characteristics

Ryo Uchida; Yasuo Moriyoshi; Takagi Masahide

2006-01-01

311

Acoustic microscopy of functionally graded thermal sprayed coatings using stiffness matrix method and Stroh formalism  

NASA Astrophysics Data System (ADS)

Acoustic microscopy of multilayered media as well as functionally graded coatings on substrate necessitates to model acoustic wave propagation in such materials. In particular, we chose to use Stroh formalism and the recursive stiffness matrix method to obtain the reflection coefficient of acoustic waves on these systems because this allows us to address the numerical instability of the conventional transfer matrix method. In addition, remarkable simplification and computational efficiency are obtained. We proposed a modified formulation of the angular spectrum of the transducer based on the theoretical analysis of a line-focus transducer for broadband acoustic microscopy. A thermally sprayed coating on substrate is treated as a functionally graded material along the depth of the coating and is approximately represented by a number of homogeneous elastic layers with exponentially graded elastic properties. The agreement between our experimental and numerical analyses on such thermal sprayed coatings with different thicknesses confirms the efficiency of the method. We proved the ability of the inversion procedure to independently determine both thickness and gradient of elastic properties. The perspective of this work is the opportunity to non-destructively measure these features in functionally graded materials.

Deng, X. D.; Monnier, T.; Guy, P.; Courbon, J.

2013-06-01

312

Kinetics of biomass catalytic pyrolysis  

Microsoft Academic Search

The Coats–Redfern method was used to analyze the kinetic characteristics of biomass catalytic pyrolysis, indicating that it can be described by multi-step reactions, rather than as a simple first-order reaction. Friedman model-free calculations were used to describe the starting reaction types and the corresponding initial kinetic parameters. Finally, nonlinear regression of biomass catalytic pyrolysis showed that the reaction mechanism of

Changbo Lu; Wenli Song; Weigang Lin

2009-01-01

313

Pyrolysis of lignin in the presence of tetramethylammonium hydroxide: a convenient method for S/G ratio determination.  

PubMed

Pyrolysis-gas chromatography in the presence of tetramethylammonium hydroxide (TMAH) was applied to the determination of the ratio of the abundances of the syringyl beta-aryl ether subunits to those of the guaiacyl equivalents (S/G) in lignin. Diazomethane-methylated kenafs (Hibiscus cannabinus and Hibiscus sabdariffa) and beech (Fagus crenata) in situ lignins were employed. Relative abundances of pyrolysis products derived from the guaiacyl and syringyl beta-aryl ether subunits were determined. The S/G ratios for in situ lignins were obtained with average 3.1% relative standard deviation for a minimum of six repeated runs. The S/G ratios determined by pyrolysis in the presence of TMAH agreed well with those determined by thioacidolysis, with a significant linear regression (R(2) = 0.9867). The results showed that pyrolysis with TMAH is an effective tool for obtaining information on the S/G ratio for in situ lignins. PMID:11853474

Kuroda, Ken-ichi; Nishimura, Natsuno; Izumi, Akiko; Dimmel, Donald R

2002-02-27

314

Optimizing formulation factors in preparing chitosan microparticles by spray-drying method.  

PubMed

The chitosan only, chitosan/Pluronic F68, chitosan/gelatin, chitosan/Pluronic F68/gelatin microparticles and betamethasone-loaded chitosan/Pluronic F68/gelatin microparticles were successfully prepared by a spray-drying method. Microparticle characteristics (yield rate, zeta potential, particle size and tap density), loading efficiencies, microparticle morphology and in-vitro release properties were investigated. By properly choosing excipient type, concentration and varying the spray-drying parameters, a high degree of control was achieved over the physical properties of the dry chitosan powders. SEM micrograph shows that the particle sizes of the varied chitosan composed microparticles ranged from 2.12-5.67 microm and the external surfaces appear smooth. Using betamethasone as model drug, the spray-drying is a promising way to produce good spherical and smooth surface microparticles with a narrow particle size range for controlled delivery of betamethasone. The positively charged betamethasone-loaded microparticles entrapped in the chitosan/Pluronic F68/gelatin microparticles with trapping efficiencies up to 94.5%, yield rate 42.5% and mean particle size 5.64 microm varied between 4.32-6.20 microm and tap densities 0.128 g/cm(3). The pH of particle was increased with increasing betamethasone-loaded amount, but both zeta potential and tap density of the particles decreased with increasing betamethasone-loaded amount. The betamethasone release rates from chitosan/Pluronic F68/gelatin microparticles were influenced by the drug/polymer ratio in the manner that an increase in the release% and burst release% was observed when the drug loading was decreased. The in vitro release of betamethasone showed a dose-dependent burst followed by a slower release phase that was proportional to the drug concentration in the concentration range between 14-44%w/w. PMID:12554378

Huang, Y-C; Chiang, C-H; Yeh, M-K

2003-01-01

315

High-quality quantum-dot-based full-color display technology by pulsed spray method  

NASA Astrophysics Data System (ADS)

We fabricated the colloidal quantum-dot light-emitting diodes (QDLEDs) with the HfO2/SiO2-distributed Bragg reflector (DBR) structure using a pulsed spray coating method. Moreover, pixelated RGB arrays, 2-in. wafer-scale white light emission, and an integrated small footprint white light device were demonstrated. The experimental results showed that the intensity of red, blue, and green (RGB) emissions exhibited considerable enhancement because of the high reflectivity in the UV region by the DBR structure, which subsequently increased the use in the UV optical pumping of RGB QDs. In this experiment, a pulsed spray coating method was crucial in providing uniform RGB layers, and the polydimethylsiloxane (PDMS) film was used as the interface layer between each RGB color to avoid crosscontamination and self-assembly of QDs. Furthermore, the chromaticity coordinates of QDLEDs with the DBR structure remained constant under various pumping powers in the large area sample, whereas a larger shift toward high color temperatures was observed in the integrated device. The resulting color gamut of the proposed QDLEDs covered an area 1.2 times larger than that of the NTSC standard, which is favorable for the next generation of high-quality display technology.

Chen, Kuo-Ju; Chen, Hsin-Chu; Tsai, Kai-An; Lin, Chien-Chung; Tsai, Hsin-Han; Chien, Shih-Hsuan; Cheng, Bo-Siao; Hsu, Yung-Jung; Shih, Min-Hsiung; Kuo, Hao-Chung

2013-03-01

316

Deposition of titanium nitride layers by electric arc - Reactive plasma spraying method  

NASA Astrophysics Data System (ADS)

Titanium nitride (TiN) is a ceramic material which possesses high mechanical properties, being often used in order to cover cutting tools, thus increasing their lifetime, and also for covering components which are working in corrosive environments. The paper presents the experimental results on deposition of titanium nitride coatings by a new combined method (reactive plasma spraying and electric arc thermal spraying). In this way the advantages of each method in part are combined, obtaining improved quality coatings in the same time achieving high productivity. Commercially pure titanium wire and C45 steel as substrate were used for experiments. X-ray diffraction analysis shows that the deposited coatings are composed of titanium nitride (TiN, Ti2N) and small amounts of Ti3O. The microstructure of the deposited layers, investigated both by optical and scanning electron microscopy, shows that the coatings are dense, compact, without cracks and with low porosity. Vickers microhardness of the coatings presents maximum values of 912 HV0.1. The corrosion tests in 3%NaCl solution show that the deposited layers have a high corrosion resistance compared to unalloyed steel substrate.

?erban, Viorel-Aurel; Ro?u, Radu Alexandru; Bucur, Alexandra Ioana; Pascu, Doru Romulus

2013-01-01

317

Physical properties of chemically sprayed tin oxide and indium tin oxide transparent conductive films  

Microsoft Academic Search

Optical and electrical properties of transparent conductive oxide films of undoped and doped SnO2 and In2O3 prepared using the pyrolysis spray method were studied. The optical constants extracted from transmittance and reflectance measurements between 0.25 and 3 mu m are interpreted to give values of the direct allowed band gap (4.54 eV for SnO2:F and 3.80 eV for ITO) and

F. Demichelis; E. Minetti-Mezzetti; V. Smurro; A. Tagliaferro; E. Tresso

1985-01-01

318

Investigation of Chemical Spray and Electrodeposition Techniques for the Growth of Thin Film CdTe Solar Cell Materials. Final Report.  

National Technical Information Service (NTIS)

This work is concerned with the spray pyrolysis and electrodeposition of thin CdTe films. Cadmium telluride films have been successfully formed by both chemical spray pyrolysis and electrodeposition. The sprayed films range in thickness from 1 to 4 mu m a...

J. L. Boone T. P. Van Doren

1982-01-01

319

Determination of absolute coccolith abundances in deep-sea sediments by spiking with microbeads and spraying (SMS-method)  

Microsoft Academic Search

A quick new method is described for the quantification of absolute nannofossil proportions in deep-sea sediments. This method (SMS) is the combination of Spiking a sample with Microbeads and Spraying it on a cover slide. It is suitable for scanning electron microscope (SEM) analyses and for light microscope (LM) analyses. Repeated preparation and counting of the same sample (30 times)

Jörg Bollmann; Bernhard Brabec; Mara Y Cortés; Markus Geisen

1999-01-01

320

A composition joint PDF method for the modeling of spray flames  

NASA Technical Reports Server (NTRS)

This viewgraph presentation discusses an extension of the probability density function (PDF) method to the modeling of spray flames to evaluate the limitations and capabilities of this method in the modeling of gas-turbine combustor flows. The comparisons show that the general features of the flowfield are correctly predicted by the present solution procedure. The present solution appears to provide a better representation of the temperature field, particularly, in the reverse-velocity zone. The overpredictions in the centerline velocity could be attributed to the following reasons: (1) the use of k-epsilon turbulence model is known to be less precise in highly swirling flows and (2) the swirl number used here is reported to be estimated rather than measured.

Raju, M. S.

1995-01-01

321

Optical characterization of eu-doped and undoped gd(2)o(3) nanoparticles synthesized by the hydrogen flame pyrolysis method.  

PubMed

Rare-earth-doped nanoparticles are promising materials for fluorescent labeling, as they are characterized by a high Stokes shift, narrow emission spectra, long lifetimes, minimized photobleaching, and low toxicity. We examined the structural and optical properties of europium-doped gadolinium oxide nanoparticles synthesized by the flame pyrolysis method, with specific emphasis on full spectral characterization and fluorescence kinetics. The emission-excitation characterization revealed the presence of predominantly monoclinic but also highly luminescent cubic phases with a prominent oxygen-to-europium charge-transfer band in the 230-260 nm range. A broad emission band in the visible region, corresponding to a similar band in undoped Gd(2)O(3), related to the matrix surface defects, was observed in time-gated spectroscopy of doped nanopowders. All of the examined nanopowders showed very short decay components, on the order of 2 ns, and much longer millisecond decay times characteristic of lanthanide ions. At intermediate times, on the order of 20-100 ns, a complex behavior of the decay was observed, indicative of progressive energy transfer to the lanthanide ion, which varied with different intrashell transitions. Structural characterization data by means of XRD measurements allowed for unambiguous determination of the Eu:Gd(2)O(3) crystallographic structure and cell dimensions to be consistent with a predominantly monoclinic phase. PMID:17090033

Goldys, Ewa M; Drozdowicz-Tomsia, Krystyna; Jinjun, Sun; Dosev, Dosi; Kennedy, Ian M; Yatsunenko, Sergiey; Godlewski, Marek

2006-11-15

322

Thermal sprayed composite melt containment tubular component and method of making same  

DOEpatents

A tubular thermal sprayed melt containment component for transient containment of molten metal or alloy wherein the tubular member includes a thermal sprayed inner melt-contacting layer for contacting molten metal or alloy to be processed, a thermal sprayed heat-generating layer deposited on the inner layer, and an optional thermal sprayed outer thermal insulating layer. The thermal sprayed heat-generating layer is inductively heated as a susceptor of an induction field or electrical resistively heated by passing electrical current therethrough. The tubular thermal sprayed melt containment component can comprise an elongated melt pour tube of a gas atomization apparatus where the melt pour tube supplies molten material from a crucible to an underlying melt atomization nozzle.

Besser, Matthew F. (Urbandale, IA); Terpstra, Robert L. (Ames, IA); Sordelet, Daniel J. (Ames, IA); Anderson, Iver E. (Ames, IA)

2002-03-19

323

The structure of Fe-Cr-B coatings obtained using selected methods of thermal spraying  

NASA Astrophysics Data System (ADS)

This paper presents issues connected with the production of protective coatings via thermal spraying. Information about wire coating materials which contain phases from the Fe-Cr-B system is presented. Arc thermal spraying is characterised and its possible applications are determined. The results of the examinations of the structure of coatings obtained by means of various arc spraying systems are discussed. Coatings of this type are used in the machine building and power engineering industries.

Szyma?ski, K.; Szpak, M.

2012-05-01

324

An approximate method for analyzing transient condensation on spray in HYLIFE-II  

SciTech Connect

The HYLIFE-II conceptual design calls for analysis of highly transient condensation on droplets to achieve a rapidly decaying pressure field. Drops exposed to the required transient vapor pressure field are first heated by condensation but later begin to reevaporate after the vapor temperature falls below the drop surface temperature. An approximate method of analysis has been developed based on the assumption that the thermal resistance is concentrated in the liquid. The time dependent boundary condition is treated via the Duhamel integral for the pure conduction model. The resulting Nusselt number is enhanced to account for convection within the drop and then used to predict the drop mean temperature history. Many histories are considered to determine the spray rate necessary to achieve the required complete condensation.

Bai, R.Y.; Schrock, V.E. (California Univ., Berkeley, CA (USA). Dept. of Nuclear Engineering)

1990-01-01

325

A high order moment method simulating evaporation and advection of a polydisperse liquid spray  

NASA Astrophysics Data System (ADS)

In this paper, we tackle the modeling and numerical simulation of sprays and aerosols, that is dilute gas-droplet flows for which polydispersity description is of paramount importance. Starting from a kinetic description for point particles experiencing transport either at the carrier phase velocity for aerosols or at their own velocity for sprays as well as evaporation, we focus on an Eulerian high order moment method in size and consider a system of partial differential equations (PDEs) on a vector of successive integer size moments of order 0 to N, N > 2, over a compact size interval. There exists a stumbling block for the usual approaches using high order moment methods resolved with high order finite volume methods: the transport algorithm does not preserve the moment space. Indeed, reconstruction of moments by polynomials inside computational cells coupled to the evolution algorithm can create N-dimensional vectors which fail to be moment vectors: it is impossible to find a size distribution for which there are the moments. We thus propose a new approach as well as an algorithm which is second order in space and time with very limited numerical diffusion and allows to accurately describe the advection process and naturally preserves the moment space. The algorithm also leads to a natural coupling with a recently designed algorithm for evaporation which also preserves the moment space; thus polydispersity is accounted for in the evaporation and advection process, very accurately and at a very reasonable computational cost. These modeling and algorithmic tools are referred to as the Eulerian Multi Size Moment (EMSM) model. We show that such an approach is very competitive compared to multi-fluid approaches, where the size phase space is discretized into several sections and low order moment methods are used in each section, as well as with other existing high order moment methods. An accuracy study assesses the order of the method as well as the low level of numerical diffusion on structured meshes. Whereas the extension to unstructured meshes is provided, we focus in this paper on cartesian meshes and two 2D test-cases are presented: Taylor-Green vortices and turbulent free jets, where the accuracy and efficiency of the approach are assessed.

Kah, D.; Laurent, F.; Massot, M.; Jay, S.

2012-01-01

326

Pyrolysis of Waste Paper: Characterization and Composition of Pyrolysis Oil  

Microsoft Academic Search

This article presents the results of an experimental study of waste paper pyrolysis in tubular furnace pyrolysis equipment. Pyrolysis of waste paper has been conducted in different pyrolysis temperatures and heating rates to investigate the product distribution and yields of pyrolysis products. The pyrolysis oil was characterized by elemental analysis and various chromatographic and spectroscopic techniques, which are HPLC, H

Lin Li; Hongxun Zhang; Xuliang Zhuang

2005-01-01

327

A pyrolysis/gas chromatographic method for the determination of hydrogen in solid samples  

NASA Technical Reports Server (NTRS)

A method is described for the determination of hydrogen in solid samples. The sample is heated under vacuum after which the evolved gases are separated by gas chromatography with a helium ionization detector. The system is calibrated by injecting known amounts of hydrogen, as determined manometrically. The method, which is rapid and reliable, was checked for a variety of lunar soils; the limit of detection is about 10 ng of hydrogen.

Carr, R. H.; Bustin, R.; Gibson, E. K.

1987-01-01

328

Production and Analysis of Fast Pyrolysis Oils from Proteinaceous Biomass  

Microsoft Academic Search

Fast pyrolysis of lignocellulosic biomass is a facile method for producing high yields of liquid fuel intermediates. However,\\u000a because most fast pyrolysis oils are highly oxygenated, acidic, and unstable, identification of feedstocks that produce higher\\u000a quality pyrolysis liquids is desirable. Therefore, the effect of feedstock protein content was studied by performing fast\\u000a pyrolysis experiments on biomass with varying protein content.

Charles A. Mullen; Akwasi A. Boateng

329

PYROLYSIS AND COMBUSTION OF SCRAP TIRE  

Microsoft Academic Search

In this paper a literature review of both pyrolysis and combustion processes of scrap tires is presented. The work reports, the characteristics of materials, methods, effect of various process parameters, kinetic modelling applied to the pyrolysis and combustion of tires, characteristics of the products and emissions. From the published works results that scrap tire rubber consists of about 60 wt.%

M. Juma; Z. Kore?ová; J. Annus

330

Catalytic pyrolysis of cellulose with sulfated metal oxides: a promising method for obtaining high yield of light furan compounds.  

PubMed

Pyrolysis-gas chromatography/mass-spectrometry (Py-GC/MS) was employed to achieve fast pyrolysis of cellulose and on-line analysis of the pyrolysis vapors. Three sulfated metal oxides (SO(4)(2-)/TiO(2), SO(4)(2-)/ZrO(2) and SO(4)(2-)/SnO(2)) were prepared and used for catalytic cracking of the pyrolysis vapors. The distribution of the pyrolytic products was significantly altered by the catalysts. Those important primary pyrolytic products, such as levoglucosan and hydroxyacetaldehyde, were significantly decreased or even completely eliminated. Meanwhile, the catalysis increased three light furan compounds (5-methyl furfural, furfural and furan) greatly. In regard to the selectivity of the three catalysts, the SO(4)(2-)/SnO(2) was the most effective catalyst for obtaining 5-methyl furfural, while the SO(4)(2-)/TiO(2) favored the formation of furfural and the SO(4)(2-)/ZrO(2) favored the formation of furan. PMID:19473837

Lu, Qiang; Xiong, Wan-Ming; Li, Wen-Zhi; Guo, Qing-Xiang; Zhu, Xi-Feng

2009-10-01

331

Paper spray mass spectrometry-based method for analysis of droplets in a gravity-driven microfluidic chip.  

PubMed

This work presents a paper spray mass spectrometry-based method, to analyze microdroplets produced in a gravity-driven microchip. Droplets at ambient pressure were passively transferred from the chip to a paper substrate by the capillary wicking effect. Paper spray ionization was then performed for mass spectrometry (MS) analysis of droplet contents. The qualitative and quantitative analytical performances of this technique for single droplets were demonstrated. This manually controlled interface is straightforward, low-cost and simple to implement. Moreover, paper spray ionization MS holds promise in the direct analysis of real biological/chemical microreaction samples because of its tolerance with complex matrices. As a proof-of-concept example, the droplet-based acetylcholine hydrolysis was carried out to demonstrate the validation of our method for the direct analysis of micro-chemical/biological reactions. We also introduced a flow injection analysis (FIA) system combined with our droplet system to generate a concentration gradient. As a result, the microreaction can be performed at different concentrations and kinetic information can be obtained in one sample injection. In conclusion, the combination of a microdroplet chip with paper spray ionization and the introduction of the FIA system and make our droplet-MS scheme a useful platform for monitoring and analyzing organic-phase chemical/biological reactions. PMID:24432351

Zhang, Yandong; Li, Haifang; Ma, Yuan; Lin, Jin-Ming

2014-03-01

332

Characterization of polycyclic aromatic hydrocarbons (PAHs) on lime spray dryer (LSD) ash using different extraction methods.  

PubMed

In this study, traditional Soxhlet, automatic Soxhlet and ultrasonic extraction techniques were employed to determine the speciation and concentration of polycyclic aromatic hydrocarbons (PAHs) on lime spray dryer (LSD) ash samples collected from the baghouse of a spreader stoker boiler. To test the efficiencies of different extraction methods, LSD ash samples were doped with a mixture of 16 US EPA specified PAHs to measure the matrix spike recoveries. The results showed that the spike recoveries of PAHs were different using these three extraction methods with dichloromethane (DCM) as the solvent. Traditional Soxhlet extraction achieved slightly higher recoveries than automatic Soxhlet and ultrasonic extraction. Different solvents including toluene, DCM:acetone (1:1 V/V) and hexane:acetone (1:1 V/V) were further examined to optimize the recovery using ultrasonic extraction. Toluene achieved the highest spike recoveries of PAHs at a spike level of 10 microg kg(-1). When the spike level was increased to 50 microg kg(-1), the spike recoveries of PAHs also correspondingly increased. Although the type and concentration of PAHs detected on LSD ash samples by different extraction methods varied, the concentration of each detected PAH was consistently low, at microg kg(-1) levels. PMID:15990154

Sun, Ping; Weavers, Linda K; Taerakul, Panuwat; Walker, Harold W

2006-01-01

333

Thermal Diffusivity Measurement for Thermal Spray Coating Attached to Substrate Using Laser Flash Method  

NASA Astrophysics Data System (ADS)

Ceramic-based thermal barrier coatings are used as heat and wear shields of gas turbine blades. There is a strong need to evaluate the thermal conductivity of coating for thermal design and use. The thermal conductivity of a bulk material is obtained as the product of thermal diffusivity, specific heat capacity, and density above room temperature in many cases. Thermal diffusivity and thermal conductivity are unique for a given material because they are sensitive to the structure of the material. Therefore, it is important to measure them in each sample. However it is difficult to measure the thermal diffusivity and thermal conductivity of coatings because coatings are attached to substrates. In order to evaluate the thermal diffusivity of a coating attached to the substrate, we have examined the laser flash method with the multilayer model on the basis of the response function method. We carried out laser flash measurements in layered samples composed of a CoNiCrAlY bond coating and a 8YSZ top coating by thermal spraying on a Ni-based superalloy substrate. It was found that the procedure using laser flash method with the multilayer model is useful for the thermal diffusivity evaluation of a coating attached to a substrate.

Akoshima, Megumi; Tanaka, Takashi; Endo, Satoshi; Baba, Tetsuya; Harada, Yoshio; Kojima, Yoshitaka; Kawasaki, Akira; Ono, Fumio

2011-11-01

334

Chemometric methods for studying the effects of chemicals on cellulose pyrolysis by thermogravimetry–mass spectrometry  

Microsoft Academic Search

Chemometric methods were used for extracting information out of the mixture mass spectra recorded in a thermogravimetric–mass spectrometric (TG–MS) analysis. Principal Component Analysis (PCA) and Discriminant Rotation (DR) were applied for studying the effects of fire retardants on the gases evolved during thermal degradation of cellulose. The chemicals (NH4)2SO4, (NH4)2HPO4 and a commercial retardant (Fire Trol) were used as fire

A. Pappa; K. Mikedi; N. Tzamtzis; M. Statheropoulos

2003-01-01

335

Conductivity improvements to spray-produced LiFePO 4 by addition of a carbon source  

Microsoft Academic Search

We present order-of-magnitude conductivity data for “carbon-included” lithium iron phosphate (LFP) powders lightly pelletised as used as cathodes in Li-ion batteries. The powders were synthesised by a spray pyrolysis method, with a short ameliorating sinter to optimise phase purity. Carbon was introduced into the materials by adding stoichiometric amounts of sucrose into the starting ingredients. We obtained X-ray diffraction patterns

S. L. Bewlay; K. Konstantinov; G. X. Wang; S. X. Dou; H. K. Liu

2004-01-01

336

Effect of acetic acid complex on physical properties of nanostructured spray deposited FeCdS 3 thin films  

Microsoft Academic Search

Spray pyrolysis method which is simple as well as economic was used for the preparation of ternary nanostructured FeCdS3 thin films onto glass substrates from ferric nitrate and cadmium chloride as Cd and Fe source and acetic acid as a complexing agent. The prepared films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and optical absorption techniques. The

A. U. Ubale; S. G. Ibrahim

2011-01-01

337

Laser melted ZrO 2–Y 2O 3 thermal barrier obtained by plasma spraying method  

Microsoft Academic Search

The aim of the paper is to determine the influence of laser melting upon the selected physical properties of ZrO2–Y2O3 ceramic coatings deposited by APS method on super-alloys which function as TBC. Laser melting which helps to eliminate pores and other structural defects of coatings deposited by plasma spraying method should contribute to the improvement of their density and durability

Krystyna Kobyla?ska Szkaradek

2010-01-01

338

Comparison of Isolated Indentation and Grid Indentation Methods for HVOF Sprayed Cermets  

NASA Astrophysics Data System (ADS)

This paper compares the results of two approaches of instrumented indentation for characterization of mechanical properties of HVOF coatings. Three types of HVOF sprayed coatings (Cr3C2-NiCr, WC-Co, (Ti, Mo)(C,N)-NiCo) were investigated by the means of isolated nanoindentation and grid indentation methods. The results of the isolated indentation revealed hardness and elastic modulus of the individual phases in very good agreement with the corresponding bulk material. The grid indentation method, based on statistical evaluation of a large number of indentations, was influenced by the carbide-matrix interface, which gave rise to a third peak apart from the two peaks corresponding to the carbides and metallic matrix. As a consequence, the bimodal Gaussian fit was insufficient and a trimodal fit had to be used. The results extracted from low load grid nanoindentations were quite close to the results of isolated indentations whereas higher load grid nanoindentation revealed overall properties of the coating.

Nohava, Ji?í; Haušild, Petr; Houdková, Šárka; Enžl, Radek

2012-06-01

339

Manufacturing Method for Photo-Voltaic Materials by Chemical Spray Pulverization.  

National Technical Information Service (NTIS)

Acetonitrile has been shown to be a suitable carrier solvent for the preparation of thin layers of cuprous sulphide by chemical atomization. A reactive spraying apparatus for monodispersed mist has been developed. It is claimed to be indispensable for est...

M. Savelli J. Lahaye J. Vedel

1983-01-01

340

Selective laser pyrolysis of metallo-organics as a method of forming patterned thin film superconductors  

SciTech Connect

This patent describes a method for forming patterned films of superconductive materials forming a solution from the neodecanoates of yttrium, barium and copper. The neodecanoates forming an oxide mixture exhibiting superconductive properties upon subsequent thermal decompositions wherein the oxide mixture is characterized by a ratio of yttrium:barium:copper of approximately 1:2:4, the solution comprising an organic solvent such as xylene; adding to the solution an appropriate dye, depositing a film of the solution having the dye onto a strontium titanate substrate; exposing selective regions of the film with an Argon laser emitting the wavelength of light, such that the exposed regions of the film become insoluble in the xylene; immersing the film into the xylene so that the soluble; unexposed regions of the film are removed from the substrate; heating the film to thermally decompose the neodecanoates into a film containing yttrium, barium and copper oxides; to promote recrystallization and grain growth of the metal oxides within the film and induce a change therein by which the film exhibits superconducting properties.

Mantese, J.V.; Catalan, A.B.; Sell, J.A.; Meyer, M.S.; Mance, A.M.

1990-04-10

341

Heat of wood pyrolysis  

Microsoft Academic Search

The heat of pyrolysis of beech and spruce wood was investigated by means of a differential scanning calorimeter. Wide variations were found for the heat of the primary pyrolysis process, depending on the initial sample weight and on the conditions used in the measurements. However, reporting the heat of the primary pyrolysis process versus the final char yield resulted in

J. Rath; M. G. Wolfinger; G. Steiner; G. Krammer; F. Barontini; V. Cozzani

2003-01-01

342

10 CFR 431.264 - Uniform test method for the measurement of flow rate for commercial prerinse spray valves.  

Code of Federal Regulations, 2010 CFR

...measurement of flow rate for commercial prerinse spray valves. 431.264 Section 431.264...INDUSTRIAL EQUIPMENT Commercial Prerinse Spray Valves Test Procedures § 431.264...measurement of flow rate for commercial prerinse spray valves. (a) Scope. This...

2010-01-01

343

10 CFR 431.264 - Uniform test method for the measurement of flow rate for commercial prerinse spray valves.  

Code of Federal Regulations, 2010 CFR

...measurement of flow rate for commercial prerinse spray valves. 431.264 Section 431.264...INDUSTRIAL EQUIPMENT Commercial Prerinse Spray Valves Test Procedures § 431.264...measurement of flow rate for commercial prerinse spray valves. (a) Scope. This...

2009-01-01

344

Kinetic investigation of wood pyrolysis  

SciTech Connect

The objective of this investigation was to determine the kinetics of the primary reactions of wood pyrolysis. A new experimental method was developed which enabled us to measure the rate of gas, tar, and char production while taking into account the temperature variations during the wood heating up. The experimental method developed did not require any sophisticated instruments. It facilitated the collection of gas, tar and residue (unreacted wood and char) as well as accurate measurement of the temperature inside the wood sample. Expressions relating the kinetic parameters to the measured variables were derived. The pyrolysis kinetics was investigated in the range of 300 to 400/sup 0/C at atmospheric pressure and under nitrogen atmosphere. Reaction temperature and mass fractions of gas, tar, and residue were measured as a function of time. Assuming first-order reactions, the kinetic parameters were determined using differential method. The measured activation energies of wood pyrolysis to gas, tar, and char were 88.6, 112.7, and 106.5 kJ/mole, respectively. These kinetic data were then used to predict the yield of the various pyrolysis products. It was found that the best prediction was obtained when an integral-mean temperature obtained from the temperature-time curve was used as reaction temperature. The pyrolysis products were analyzed to investigate the influence of the pyrolysis conditions on the composition. The gas consisted mainly of carbon dioxide, carbon monoxide, oxygen, and C/sub 3//sup +/-compounds. The gas composition depended on reaction time as well as reactor temperature. The tar analysis indicated that the tar consisted of about seven compounds. Its major compound was believed to be levoglucosan. Elemental analysis for the char showed that the carbon content increased with increasing temperature.

Thurner, F.; Mann, U.; Beck, S. R.

1980-06-01

345

Fluorine doped-tin oxide prepared using spray method for dye sensitized solar cell application  

NASA Astrophysics Data System (ADS)

Fluorine-doped Tin Oxide (FTO) film was fabricated by spray deposition method. FTO films were prepared in different sheet resistance 6.7, 12.1, 19.3, and 23.5 ?/sq. X-ray diffractograms showed that the as-grown FTO film was tetragonal SnO2. The prepared FTO film have an average transmittance of 80% in the visible region (?=400-800 nm). These FTO films were then used to fabricate Dye Sensitized Solar Cell (DSSC). The working electrode was made from TiO2 paste using doctor blade technique. DSSC samples were characterized using solar simulator under AM 1.5 (100 mW/cm2). It is found that the efficiency of DSSC was much affected by sheet resistance of FTO film. The efficiency of DCCS was 2.32, 2.4, 1.1 and 0.97 (%) for the FTO sheet resistance 6.7, 12.1, 19.3, and 23.5 ?/sq, respectively. It is shown that the optimum DSSC efficiency was made from FTO with sheet resistance 12.1 ?/sq.

Widiyandari, Hendri; Purwanto, Agus; Diharjo, Kuncoro; Suyitno; Hidayanto, Eko

2013-09-01

346

Evaluation of methods to reduce bacteria concentrations in spray-dried animal plasma and its effects on nursery pig performance.  

PubMed

Four experiments with 1,040 weanling pigs (17 +/- 2 d of age at weaning) were conducted to evaluate the effects of spray-dried animal plasma source, drying technique, and methods of bacterial reduction on nursery pig performance. In Exp. 1, 180 barrows and gilts (initial BW 5.9 +/- 1.8 kg) were used to compare effects of animal plasma, animal plasma source, drying technique (spray-dried or freeze-dried), and plasma irradiation in nursery pig diets. From d 0 to 10, pigs fed diets containing irradiated spray-dried animal plasma had increased ADG and ADFI (P < 0.05) compared with pigs fed diets containing nonirradiated spray-dried animal plasma. Pigs fed irradiated animal plasma Sources 1 and 2 were similar in ADG and ADFI, but pigs fed animal plasma Source 1 had greater ADG (P < 0.05) than pigs fed animal plasma Source 2 and pigs not fed plasma. Pigs fed freeze-dried animal plasma had growth performance similar (P > 0.36) to pigs fed spray-dried animal plasma. Overall (d 0 to 24), pigs fed irradiated spray-dried animal plasma were heavier (P < 0.05) than pigs fed no animal plasma, whereas pigs fed nonirradiated spray-dried plasma were intermediate. In Exp. 2, 325 barrows and gilts (initial BW 5.8 +/- 1.7 kg) were used to compare the effects of irradiation or formaldehyde treatment of animal plasma and formaldehyde treatment of the whole diet. Pigs fed diets containing irradiated animal plasma had greater ADG (P < 0.05) than pigs fed nonirradiated plasma. Pigs fed formaldehyde-treated plasma had greater ADG and ADFI (P < 0.05) than pigs fed diets with either nonirradiated plasma or whole diet treated with formaldehyde. In Exp. 3 (360 barrows and gilts; initial BW 6.3 +/- 2.7 kg) and Exp. 4 (175 barrows and gilts; initial BW 6.1 +/- 1.7 kg), the irradiation of feed (high bacteria) and food-grade (low bacteria) animal plasma in nursery pig diets was examined. Pigs fed irradiated feed-grade plasma Product 2 had increased ADG (P < 0.05) compared with pigs fed nonirradiated plasma Product 2 and pigs fed the control diet without plasma. In Exp. 3 and 4, pigs fed irradiated food-grade plasma had growth performance similar to pigs fed nonirradiated food-grade plasma (P > 0.12). These studies indicate that bacterial reduction of feed-grade, but not food-grade animal plasma, improves nursery pig performance. PMID:14753369

DeRouchey, J M; Tokach, M D; Nelssen, J L; Goodband, R D; Dritz, S S; Woodworth, J C; James, B W; Webster, M J; Hastad, C W

2004-01-01

347

A comparative study of concentration effect of complexing agent on the properties of spray deposited Sb 2S 3 thin films and precipitated powders  

Microsoft Academic Search

Sb2S3 semiconducting thin films and precipitated powders have been prepared by a spray pyrolysis technique and bulk precipitation method, respectively. The concentration of solution is kept constant at 0.1 M and only the concentration of complexing agent (tartaric acid) is varied from 0.25 M to 1 M. The thickness of the film measured by weight difference method is found to

K. Y. Rajpure; C. D. Lokhande; C. H. Bhosale

1997-01-01

348

The effect of hygroscopicity on sea-spray aerosol fluxes: a comparison of high-rate and bulk correction methods  

NASA Astrophysics Data System (ADS)

The eddy covariance technique is the most direct of the methods that have been used to measure the flux of sea-spray aerosol between the ocean and atmosphere, but has been applied in only a handful of studies. However, unless the aerosol is dried before the eddy covariance measurements are made, the hygroscopic nature of sea-spray may combine with a relative humidity flux to result in a bias in the calculated aerosol flux. "Bulk" methods have been presented to account for this bias, however they rely on assumptions of the shape of the aerosol spectra which may not be valid for near-surface measurements of sea-spray. Here we describe a method of correcting aerosol spectra for relative humidity induced size variations at the high frequency (10 Hz) measurement timescale, where counting statistics are poor and the spectral shape cannot be well represented by a simple power law. Such a correction allows the effects of hygroscopicity and relative humidity flux on the aerosol flux to be explicitly evaluated and compared to the bulk corrections, both in their original form and once reformulated to better represent the measured mean aerosol spectra. In general, the bulk corrections - particularly when reformulated for the measured mean aerosol spectra - perform relatively well, producing flux corrections of the right sign and approximate magnitude. However, there are times when the bulk methods either significantly over- or underestimate the required flux correction. We thus conclude that, where possible, relative humidity corrections should be made at the measurement frequency.

Sproson, D. A. J.; Brooks, I. M.; Norris, S. J.

2012-09-01

349

Electrochemical characteristics of silicon coated graphite prepared by gas suspension spray method for anode material of lithium secondary batteries  

Microsoft Academic Search

Silicon-coated graphite particles were tested as anodes for lithium ion rechargeable batteries. The synthetic graphite particles\\u000a were first coated with silicon precursor containing solution by gas suspension spray method and then calcined at heat treatment\\u000a temperature at 500 ?C under hydrogen atmosphere. The silicon-coated graphite showed high specific capacity and good cycle\\u000a performance due to the formation of amorphous silicon-carbon

Bup Ju Jeon; Sung Won Kang; Joong Kee Lee

2006-01-01

350

Method and closing pores in a thermally sprayed doped lanthanum chromite interconnection layer  

DOEpatents

A dense, substantially gas-tight electrically conductive interconnection layer is formed on an air electrode structure of an electrochemical cell by (A) providing an air electrode surface; (B) forming on a selected portion of the electrode surface, a layer of doped LaCrO.sub.3 particles doped with an element or elements selected from Ca, Sr, Ba, Mg, Co, Ni, Al and mixtures thereof by thermal spraying doped LaCrO.sub.3 particles, either by plasma arc spraying or flame spraying; (C) depositing a mixture of CaO and Cr.sub.2 O.sub.3 on the surface of the thermally sprayed layer; and (D) heating the doped LaCrO.sub.3 layer coated with CaO and Cr.sub.2 O.sub.3 surface deposit at from about 1000.degree. C. to 1200.degree. C. to substantially close the pores, at least at a surface, of the thermally sprayed doped LaCrO.sub.3 layer. The result is a dense, substantially gas-tight, highly doped, electrically conductive interconnection material bonded to the electrode surface. A solid electrolyte layer can be applied to the nonselected portion of the air electrode. A fuel electrode can be applied to the solid electrolyte, to form an electrochemical cell, for example for generation of electrical power.

Singh, Prabhakar (Export, PA); Ruka, Roswell J. (Pittsburgh, PA)

1995-01-01

351

Method and closing pores in a thermally sprayed doped lanthanum chromite interconnection layer  

DOEpatents

A dense, substantially gas-tight electrically conductive interconnection layer is formed on an air electrode structure of an electrochemical cell by (A) providing an air electrode surface; (B) forming on a selected portion of the electrode surface, a layer of doped LaCrO{sub 3} particles doped with an element or elements selected from Ca, Sr, Ba, Mg, Co, Ni, Al and mixtures thereof by thermal spraying doped LaCrO{sub 3} particles, either by plasma arc spraying or flame spraying; (C) depositing a mixture of CaO and Cr{sub 2}O{sub 3} on the surface of the thermally sprayed layer; and (D) heating the doped LaCrO{sub 3} layer coated with CaO and Cr{sub 2}O{sub 3} surface deposit at from about 1,000 C to 1,200 C to substantially close the pores, at least at a surface, of the thermally sprayed doped LaCrO{sub 3} layer. The result is a dense, substantially gas-tight, highly doped, electrically conductive interconnection material bonded to the electrode surface. A solid electrolyte layer can be applied to the nonselected portion of the air electrode. A fuel electrode can be applied to the solid electrolyte, to form an electrochemical cell, for example for generation of electrical power. 5 figs.

Singh, P.; Ruka, R.J.

1995-02-14

352

Plasma pyrolysis of toxic waste  

Microsoft Academic Search

The comparison of technical economic indexes of different waste treatment methods and plasma pyrolysis is presented in the paper. It testifies that plasma technologies are economically expedient for these purposes. Physical prerequisites allowing realizing plasma technologies are presented. Reliable and economical (70–120 Euro per ton of treated product) plasma generation is the basic condition of the technology realization. In this

Ph G Rutberg

2003-01-01

353

Superhydrophilic multilayer silica nanoparticle networks on a polymer microchannel using a spray layer-by-layer nanoassembly method.  

PubMed

Nanoporous and superhydrophilic multilayer silica nanoparticle networks have been developed on a hydrophobic cyclic olefin copolymer (COC) microchannel using a spray layer-by-layer (LbL) electrostatic nanoassembly method. This powerful and promising LbL method provides a simple, cost-effective, and high-throughput nanoporous silica multilayer selectively onto the hydrophobic polymer surfaces. These newly developed multilayer networks have also been successfully characterized by contact angle measurement, environmental scanning electron microscopy (ESEM), energy-dispersive X-ray spectroscopy (EDS), and atomic force microscopy (AFM). The superhydrophilic effect, which was confirmed by the contact angle measurements, of the silica networks ensured the hydrophilic nature of the selectively constructed nanoporous silica nanoparticles onto the patterned hydrophobic COC microchannel. The capillary effect of the developed surface was characterized by measuring the length of a test liquid driven by the induced capillary forces in an on-chip capillary pumping platform with horizontal microchannels. The pumping capability achieved from the sprayed nanoporous surface for the on-chip micropump was mainly due to the strong capillary imbibition driven by the multicoated bilayers of hydrophilic silica nanoparticles. The developed networks with spray-assembled nanoparticles were also applied for an on-chip blood plasma separation platform with closed microchannels. The spray LbL method developed in this work can be a highly practical approach for the modification of various polymer microchannels because of several advantages such as an extremely simple process for the multilayer formation and flexibly controlled surface functionality at room temperature. PMID:23915270

Lee, Kang Kug; Ahn, Chong H

2013-09-11

354

Nondestructive Evaluation of Thermal Spray Coating Interface Quality by Eddy Current Method  

NASA Astrophysics Data System (ADS)

Thermal spray coating is usually applied through directing molten or softened particles at very high velocities onto a substrate. An eddy current non-destructive inspection technique is presented here for thermal spray coating interface quality characterization. Several high-velocity-oxy-fuel (HVOF) coated steel plates were produced with various surface preparation conditions or spray process parameters. A quad-frequency eddy current probe was used to manually scan over the coating surface to evaluate the bonding quality. Experimental results show that different surface preparation conditions and varied process parameters can be successfully differentiated by the impedance value observed from the eddy current probe. The measurement is fairly robust and consistent. This non-contact, nondestructive, easy-to-use technique has the potential for evaluating the coating quality immediately after its application so that any defects can be corrected immediately.

Mi, Bao; Zhao, Xiaoliang (George); Bayles, Robert

2007-03-01

355

Non-Destructive Evaluation of Thermal Spray Coating Interface Quality By Eddy Current Method  

SciTech Connect

Thermal spray coating is usually applied through directing molten or softened particles at very high velocities onto a substrate. An eddy current non-destructive inspection technique is presented here for thermal spray coating interface quality characterization. Several high-velocity-oxy-fuel (HVOF) coated steel plates were produced with various surface preparation conditions or spray process parameters. A quad-frequency eddy current probe was used to manually scan over the coating surface to evaluate the bonding quality. Experimental results show that different surface preparation conditions and varied process parameters can be successfully differentiated by the impedance value observed from the eddy current probe. The measurement is fairly robust and consistent. This non-contact, nondestructive, easy-to-use technique has the potential for evaluating the coating quality immediately after its application so that any defects can be corrected immediately.

B. Mi; G. Zhao; R. Bayles

2006-08-10

356

Method for the determination of lignin content of a sample by flash pyrolysis in an atmosphere of hydrogen or helium and method therefor  

NASA Technical Reports Server (NTRS)

The lignin content of wood, paper pulp or other material containing lignin (such as filter paper soaked in black liquor) is more readily determined by flash pyrolysis of the sample at approximately 550.degree. C. in a reducing atmosphere of hydrogen or in an inert atmosphere of helium followed by a rapid analysis of the product gas by a mass spectrometer. The heated pyrolysis unit as fabricated comprises a small platinum cup welded to an electrically-heated stainless steel ribbon with control means for programmed short duration (1.5 sec, approximately) heating and means for continuous flow of hydrogen or helium. The pyrolysis products enter an electron-ionization mode mass spectrometer for spectral evaluation. Lignin content is obtained from certain ratios of integrated ion currents of many mass spectral lines, the ratios being linearly related to the Kappa number of Klason lignin.

Shakkottai, Parthasarathy (Inventor); Kwack, Eug Y. (Inventor); Lawson, Daniel D. (Inventor)

1991-01-01

357

Waste minimization pretreatment via pyrolysis and oxidative pyrolysis of organic ion exchange resin  

SciTech Connect

Pyrolysis and/or oxidative pyrolysis of organic ion exchange resins and other combustible waste may be effective pretreatment processes before vitrification. Three different methods were examined with the TGA to pretreat the resins: pyrolysis; oxidative pyrolysis; and oxidative pyrolyses of ash remaining after the pyrolysis of resin. The latter two methods were found to provide better volume reduction than the pyrolysis-only process. Between the two types of resins, cationic and anionic, the cationic exchange resin was less volatile. Pyrolysis and oxidative pyrolysis of mixed resin (50% cation and 50% anion by wt.) showed volatilization at the temperatures where volatilization was observed for each of the separate resins. Because of certain limitations of the commercial TGA, tube furnace experiments were performed, generally, to examine the pyrolysis of larger quantities of cationic, anionic, and mixed resin, and to examine off-gas characteristics. The cationic resin-only and anionic resin-only gravimetric results showed good agreement with the smaller-scale TGA results. SEM pictures of the different variants of the resin (cationic, anionic, and mixed) show a different morphology for each. Off-gas data showed the presence of H{sub 2}S, SO{sub 2}, CO, and NO during the pyrolysis of cationic resin. CO was observed during the pyrolysis of anionic resin. The mixed resin trials showed the presence of the gases approximately at the temperatures where the gases would evolve if the results of the two different resins (cationic and anionic) were superimposed. However, the amount of hydrogen sulfide relative to the sulfur dioxide was found to increase significantly compared to the results of the cationic resin-only trials.

Chun, U.K.; Choi, K.; Yang, K.H.; Park, J.K.; Song, M.J. [Korea Electric Power Research Inst., Taejon (Korea, Republic of). Nuclear Power Generation Lab.] [Korea Electric Power Research Inst., Taejon (Korea, Republic of). Nuclear Power Generation Lab.

1998-12-31

358

Plasma spray forming  

Microsoft Academic Search

The technology of plasma spray forming (PSF) is introduced, and the technical processes of plasma spray for fabricating parts and moulds are investigated emphatically in this paper. The technological characteristics of PSF are summarized, including original prototype fabrication and surface treatment, post-treatment of a formed workpiece and demoulding methods. Also, some important factors affecting the qualities of workpiece formed by

J. C Fang; W. J Xu

2002-01-01

359

The characteristics of betamethasone-loaded chitosan microparticles by spray-drying method.  

PubMed

Betamethasone (BTM)-loaded microparticles prepared by a spray drying method using chitosan (CTS) as raw material, type-A gelatin and ethylene oxide-propylene oxide block copolymer (Pluronic F68) as modifiers. The BTM-loaded in varied chitosan/Pluronic F68/gelatin microparticle formulations was investigated. By properly choosing excipient type and concentration a high degree of control was achieved over the physical properties of the BTM-loaded microparticles. Microparticle characteristics (zeta potential, tap density, particle size and yield), loading efficiencies, microparticle morphology and in-vitro release properties were examined. Surface morphological characteristics and surface charges of prepared microparticles were observed by using scanning electron microscopy (SEM) and microelectrophoresis. A SEM micrograph shows that the particle sizes of the varied chitosan composed microparticles ranged from 1.1-4.7 microm and the external surfaces appear smooth. The BTM-loaded microparticles entrapped in the chitosan/Pluronic F68/gelatin microparticles with trapping efficiencies up to 93%, collected yield rate 44%, and mean particle size varied between 1-3 microm, positive surface charge (20-40 mv), and tap densities (0.04-0.40 g/cm3) were obtained. The collected BTM yield and size of particle was increased with increasing BTM-loaded amount but both zeta potential and tap density of the particles decreased with increasing BTM-loaded amount. The in vitro release of BTM showed a dose-dependent burst followed by a slower release phase that was proportional to the drug concentration in the concentration range between 5-30%w/w. The in vitro drug release from the chitosan/Pluronic F68/gelatin 1/0.1/0.4 microspheres had a prolong release pattern. These formulation factors were correlated to particulate characteristics for optimizing BTM microspheres in pulmonary delivery. PMID:12851046

Huang, Y-C; Yeh, M-K; Cheng, S-N; Chiang, C-H

2003-01-01

360

Optimal design of a convergent-barrel cold spray nozzle by numerical method  

Microsoft Academic Search

A convergent-barrel (CB) cold spray nozzle was designed through numerical simulation. It was found that the main factors influencing significantly particle velocity and temperature include the length and diameter of the barrel section, the nature of the accelerating gas and its pressure and temperature, and the particle size. Particles can achieve a relatively low velocity but a high temperature under

Wen-Ya Li; Hanlin Liao; Hong-Tao Wang; Chang-Jiu Li; Ga Zhang; C. Coddet

2006-01-01

361

Hybrid Turbulence Modeling of Liquid Spray Impingement on a Heated Wall with Arbitrary Lagrangian Eulerian Method  

Microsoft Academic Search

Numerical simulation of two phase spray impingement on a heated wall was carried out. Hybrid turbulence modeling was used for analysis where large eddy simulation was employed away from the wall, and a k-epsilon model was employed near the wall. The effect of vortex motion on turbulent heat flux values was analyzed using different Reynolds numbers of impingement and at

S. Kondaraju; J. S. Lee

2007-01-01

362

Analysis of drugs by pyrolysis. II--An improved method for the determination of carpronium chloride in plasma by selected ion monitoring.  

PubMed

A sensitive and specific method has been devised for the determination of carpronium chloride, a parasympathomimetic agent, in plasma. The method is based on selected ion monitoring combined with the pyrolysis reaction of (3-isopropoxycarbopropyl)trimethylammonium chloride derived by transesterification of the drug. Carpronium chloride-[2H9] is used as an internal standard. The drug and the internal standard are separated from deproteinized plasma by ion pair extraction, and converted into isopropyl ester derivatives. The derivatives are pyrolysed to produce the respective isopropyl N,N-dimethyl-gamma-aminobutyrates available for selected ion monitoring. Measurement is carried out in the electron impact mode by monitoring the fragment ion [M-OC3H7]+ (m/z 114, 120). The method is applicable to 5 ng ml-1 plasma with about 10% coefficient of variation, and has been utilized successfully for the pharmacokinetics of carpronium chloride in man. PMID:7397317

Sano, M; Ohya, K; Shintani, S

1980-01-01

363

Fundamental Pyrolysis Studies  

SciTech Connect

Progress on the direct mass spectrometric sampling of pyrolysis products from wood and its constituents is described for the period from June 1982 to February 1983. A brief summary and references to detailed reports, of the qualitative demonstration of our approach to the study of the separated processes of primary and secondary pyrolysis is presented. Improvements and additions to the pyrolysis and data acquisition systems are discussed and typical results shown. Chief of these are a heated-grid pyrolysis system for controlled primary pyrolysis and a sheathed flame arrangement for secondary cracking studies. Qualitative results of the secondary cracking of cellulose, lignin, and wood are shown as are comparisons with the literature for the pyrolysis spectra of cellulose, lignin, and levoglucosan. 'Fingerprints' for a number of materials are shown, with spectra taken under carefully controlled conditions so that sensitivity calibrations for different compounds, now being determined, can be applied.

Milne, T. A.; Evans, R. J.; Soltys, M. N.

1983-03-01

364

Antistatic sprays  

NASA Technical Reports Server (NTRS)

Antistatic sprays from several different manufacturers are examined. The sprays are examined for contamination potential (i.e., outgassing and nonvolatile residue), corrosiveness on an aluminum mirror surface, and electrostatic effectiveness. In addition, the chemical composition of the antistatic sprays is determined by infrared spectrophotometry, mass spectrometry, and ultraviolet spectrophotometry. The results show that 12 of the 17 antistatic sprays examined have a low contamination potential. Of these sprays, 7 are also noncorrosive to an aluminum surface. And of these, only 2 demonstrate good electrostatic properties with respect to reducing voltage accumulation; these sprays did not show a fast voltage dissipation rate however. The results indicate that antistatic sprays can be used on a limited basis where contamination potential, corrosiveness, and electrostatic effectiveness is not critical. Each application is different and proper evaluation of the situation is necessary. Information on some of the properties of some antistatic sprays is presented in this document to aid in the evaluation process.

Ming, James E.

1989-01-01

365

Antistatic Sprays.  

National Technical Information Service (NTIS)

Antistatic sprays from several different manufacturers are examined. The sprays are examined for contamination potential (i.e., outgassing and nonvolatile residue), corrosiveness on an aluminum mirror surface, and electrostatic effectiveness. In addition,...

J. E. Ming

1989-01-01

366

Spray pyrolyzed NiO–C nanocomposite as an anode material for the lithium-ion battery with enhanced capacity retention  

Microsoft Academic Search

NiO–C nanocomposite was prepared by a spray pyrolysis method using a mixture of Ni(NO3)2 and citric acid solution at 600°C. The microstructure and morphology of the NiO–C composite were characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) mapping, and thermogravimetric analysis (TGA). The results showed that the NiO nanoparticles were surrounded by amorphous

M. M. Rahman; Shu-Lei Chou; Chao Zhong; Jia-Zhao Wang; David Wexler; Hua-Kun Liu

2010-01-01

367

Studies on Spray Deposited SnO2, Pd:SnO2 and F:SnO2 Thin Films for Gas Sensor Applications  

Microsoft Academic Search

Undoped tin oxide (TO), palladium?doped tin oxide (PTO) and fluorine?doped tin oxide (FTO) thin films have been prepared by spray pyrolysis method, under optimized conditions. Transmission measurement of the TO, PTO and FTO films have been studied in the UV?Visible region. Band gap energy evaluated from the spectral data lies between 3.15 eV and 3.8 eV. The X?ray diffraction analysis

N. Sankara Subramanian; B. Santhi; S. Sundareswaran; K. S. Venkatakrishnan

2006-01-01

368

Spray forming  

Microsoft Academic Search

Spray forming is a relatively new manufacturing process for near net shape preforms in a wide variety of alloys. Spray formed materials have a characteristic equiaxed microstructure with small grain sizes, low levels of solute partitioning, and inhibited coarsening of secondary phases. After consolidation to full density, spray formed materials have consistently shown properties superior to conventionally cast materials, and

P. S. Grant

1995-01-01

369

Bovine serum albumin as a lyoprotectant for preparation of DNA dry powder formulations using the spray-freeze drying method.  

PubMed

The development of efficient and selective therapeutic gene delivery methods is a potential medical treatment for intractable diseases. Dry powder inhalers (DPIs) can efficiently deliver drugs locally to the lung. Many reports discuss preparation methods for DPIs. Spray-freeze drying is a method by which highly porous particulates can be prepared. However, altered physical properties after preparation may result in changes in gene expression. In this study, bovine serum albumin (BSA) was added as a lyoprotectant, and 1,2-dioleoyl-3-trimethylammonium propane/cholesterol liposomes/pCMV-Luc DPIs (lipoplex DPIs) were prepared by spray-freeze drying. The mean particle sizes of the lipoplex DPIs prepared without BSA increased by approximately 6.7-fold compared with that of the lipoplexes solution. In contrast, the mean particle sizes of the lipoplex/BSA DPIs increased only slightly. Gene expression was evaluated after the intratracheal administration of the lipoplexes solution, with maximum gene expression observed at 12?h after the administration. In contrast, maximum gene expression of the lipoplex/BSA DPIs occurred at 6?h after administration. The gene expression associated with the lipoplex DPIs was significantly lower compared with that of the lipoplex/BSA DPIs at 6 (p<0.01), 12 (p<0.01), and 24?h (p<0.05). These variances may be due to the difference in mean particle size between the DPI formulations. The results suggest that BSA is a useful lyoprotectant for dry powder formulation preparations of DNA using the spray-freeze drying method, given that the preparation results in minimal variation of physical properties and gene expression. PMID:22791169

Tsukamoto, Masashi; Okuda, Tomoyuki; Okamoto, Hirokazu; Higuchi, Yuriko; Kawakami, Shigeru; Yamashita, Fumiyoshi; Hashida, Mitsuru

2012-01-01

370

Method for thermally spraying crack-free mullite coatings on ceramic-based substrates  

NASA Technical Reports Server (NTRS)

A process for depositing a mullite coating on a silicon-based material, such as those used to form articles exposed to high temperatures and including the hostile thermal environment of a gas turbine engine. The process is generally to thermally spray a mullite powder to form a mullite layer on a substrate, in which the thermal spraying process is performed so that the mullite powder absorbs a sufficient low level of energy from the thermal source to prevent evaporation of silica from the mullite powder. Processing includes deposition parameter adjustments or annealing to maintain or reestablish phase equilibrium in the mullite layer, so that through-thickness cracks in the mullite layer are avoided.

Spitsberg, Irene T. (Inventor); Wang, Hongyu (Inventor); Heidorn, Raymond W. (Inventor)

2000-01-01

371

Method for thermally spraying crack-free mullite coatings on ceramic-based substrates  

NASA Technical Reports Server (NTRS)

A process for depositing a mullite coating on a silicon-based material, such as those used to form articles exposed to high temperatures and including the hostile thermal environment of a gas turbine engine. The process is generally to thermally spray a mullite powder to form a mullite layer on a substrate, in which the thermal spraying process is performed so that the mullite powder absorbs a sufficient low level of energy from the thermal source to prevent evaporation of silica from the mullite powder. Processing includes deposition parameter adjustments or annealing to maintain or reestablish phase equilibrium in the mullite layer, so that through-thickness cracks in the mullite layer are avoided.

Spitsberg, Irene T. (Inventor); Wang, Hongyu (Inventor); Heidorn, Raymond W. (Inventor)

2001-01-01

372

Corrosivity Of Pyrolysis Oils  

Microsoft Academic Search

Pyrolysis oils from several sources have been analyzed and used in corrosion studies which have consisted of exposing corrosion coupons and stress corrosion cracking U-bend samples. The chemical analyses have identified the carboxylic acid compounds as well as the other organic components which are primarily aromatic hydrocarbons. The corrosion studies have shown that raw pyrolysis oil is very corrosive to

James R Keiser; Michael A Bestor; Samuel Arthur Lewis Sr; John Morse Storey

2011-01-01

373

Deposição de filmes de ZEI 8% em mol por sistema de spray pirólise modificado  

Microsoft Academic Search

In this work zirconia stabilized with itria films 8 mol% (8YSZ) had been produced, applied as electrolytes for solid oxide fuel cell (SOFC), deposited in quartz substrate spray-pyrolysis technique and treated at 1000ºC. For attainment of films a system deposition for spray-pyrolysis modified according to patent deposited in INPI was used, that if compared with traditional system where atomized is

C. H. M. Rodrigues; M. Toniato; H. R. Paes Jr

2008-01-01

374

Analytical pyrolysis evaluation of the retorting potential of Kentucky oil shale  

Microsoft Academic Search

This work is an examination of an analytical pyrolysis technique as a method for determining oil shale retorting potential. A carefully selected and prepared set of oil shale samples was evaluated by three methods: Fischer Assay, bench scale fluid bed retorting and an analytical pyrolysis method. Data are presented to show that an analytical pyrolysis based assay is an acceptable

M. J. Margolis; D. N. Taulbee; A. M. Rubel; J. L. Howard

1984-01-01

375

Decomposition of ion exchange resins by pyrolysis  

SciTech Connect

Pyrolysis of spent ion exchange resins is one of the most effective methods for reducing radioactive waster volume and for making the final waste form more stable. Fundamental experiments were performed to clarify the pyrolysis characteristics of anion and cation exchange resins. Residual elemental analyses and off-gas analyses showed that the decomposition ratio of cation resins was only 50 wt% at 600/sup 0/C, while that of anion resins was 90 wt% at 400/sup 0/C. Infrared spectroscopy for cation resins attributed its low decomposition ratio to formation of a highly heat-resistant polymer (sulfur bridged) during pyrolysis. Measurements of residual hygroscopicity and cement package strength indicated that the optimum pyrolysis temperatures for preventing resins swelling and package expansion were between 300 and 500/sup 0/C.

Matsuda, M.; Funabashi, K.; Nishi, T.; Yusa, H.; Kikuchi, M.

1986-11-01

376

Pyrolysis system evaluation study  

NASA Technical Reports Server (NTRS)

An evaluation of two different pyrolysis concepts which recover energy from solid waste was conducted in order to determine the merits of each concept for integration into a Integrated Utility System (IUS). The two concepts evaluated were a Lead Bath Furnace Pyrolysis System and a Slagging Vertical Shaft, Partial Air Oxidation Pyrolysis System. Both concepts will produce a fuel gas from the IUS waste and sewage sludge which can be used to offset primary fuel consumption in addition to the sanitary disposal of the waste. The study evaluated the thermal integration of each concept as well as the economic impact on the IUS resulting from integrating each pyrolysis concepts. For reference, the pyrolysis concepts were also compared to incineration which was considered the baseline IUS solid waste disposal system.

1974-01-01

377

A coupled implicit solution method for turbulent spray combustion in propulsion systems  

NASA Technical Reports Server (NTRS)

Many reacting flows in propulsion devices cannot be efficiently calculated by modern compressible flow CFD algorithms. Most low-speed reacting flow codes based on TEACH-type technologies are inefficient and lack robustness for complex flows. Tremendous progress has been made in high-speed compressible flow CFD in the past two decades; extending its application range to low-speed regimes is highly desirable. The objectives of this document is to present an efficient and robust algorithm for multi-phase chemically reacting flows at all speeds, with emphasis on low Mach number flows, and to calculate turbulent spray combustion flow in a gas turbine combustor.

Chen, K.-H.; Shuen, J.-S.

1993-01-01

378

Method of forming a plasma sprayed interconnection layer on an electrode of an electrochemical cell  

DOEpatents

A dense, substantially gas-tight, electrically conductive interconnection layer is formed on an air electrode structure of an electrochemical cell by (A) providing an electrode surface; (B) forming on a selected portion of the electrode surface, a layer of doped LaCrO{sub 3} particles doped with an element selected from Ca, Sr, Ba, Mg, Co, Ni, Al and mixtures thereof by plasma spraying doped LaCrO{sub 3} powder, preferably compensated with chromium as Cr{sub 2}O{sub 3} and/or dopant element, preferably by plasma arc spraying; and, (C) heating the doped and compensated LaCrO{sub 3} layer to about 1100 C to 1300 C to provide a dense, substantially gas-tight, substantially hydration-free, electrically conductive interconnection material bonded to the electrode surface. A solid electrolyte layer can be applied to the unselected portion of the air electrode, and a fuel electrode can be applied to the solid electrolyte, to provide an electrochemical cell. 6 figs.

Spengler, C.J.; Folser, G.R.; Vora, S.D.; Kuo, L.; Richards, V.L.

1995-06-20

379

Method of forming a plasma sprayed interconnection layer on an electrode of an electrochemical cell  

DOEpatents

A dense, substantially gas-tight, electrically conductive interconnection layer is formed on an air electrode structure of an electrochemical cell by (A) providing an electrode surface; (B) forming on a selected portion of the electrode surface, a layer of doped LaCrO.sub.3 particles doped with an element selected from Ca, Sr, Ba, Mg, Co, Ni, Al and mixtures thereof by plasma spraying doped LaCrO.sub.3 powder, preferably compensated with chromium as Cr.sub.2 O.sub.3 and/or dopant element, preferably by plasma arc spraying; and, (C) heating the doped and compensated LaCrO.sub.3 layer to about 1100.degree. C. to 1300.degree. C. to provide a dense, substantially gas-tight, substantially hydration-free, electrically conductive interconnection material bonded to the electrode surface. A solid electrolyte layer can be applied to the unselected portion of the air electrode, and a fuel electrode can be applied to the solid electrolyte, to provide an electrochemical cell.

Spengler, Charles J. (Murrysville, PA); Folser, George R. (Lower Burrell, PA); Vora, Shailesh D. (Monroeville, PA); Kuo, Lewis (Monroeville, PA); Richards, Von L. (Anyola, IN)

1995-01-01

380

Pyrolysis mass spectrometry and its applications in biotechnology  

Microsoft Academic Search

Pyrolysis mass spectrometry is a rapid and high-resolution method for the analysis of otherwise non-volatile material and has been widely applied for discriminating between closely related microbial strains. Recent advances in statistical and neural network methods based on supervised learning have now permitted exploitation of pyrolysis mass spectrometry in the quantitative analysis of many diverse samples of biotechnological interest; the

Royston Goodacre; Douglas B Kell

1996-01-01

381

Thermal Arc Spray Overview  

NASA Astrophysics Data System (ADS)

Usage of protective coating for corrosion protection was on highly demand during the past decade; and thermal spray coating played a major part during that time. In recent years, the thermal arc spray coating becomes a popular coating. Many big players in oil and gas such as PETRONAS, EXXON MOBIL and SHELL in Malaysia tend to use the coating on steel structure as a corrosion protection. Further developments in coating processes, the devices, and raw materials have led to expansion of functional coatings and applications scope from conventional coating to specialized industries. It is widely used because of its ability to withstand high process temperature, offer advantages in efficiency, lower cost and acts as a corrosion protection. Previous research also indicated that the thermal arc spray offers better coating properties compared to other methods of spray. This paper reviews some critical area of thermal spray coating by discussing the process/parameter of thermal arc spray technology and quality control of coating. Coating performance against corrosion, wear and special characteristic of coating are also described. The field application of arc spray technology are demonstrated and reviewed.

Hafiz Abd Malek, Muhamad; Hayati Saad, Nor; Kiyai Abas, Sunhaji; Mohd Shah, Noriyati

2013-06-01

382

DEVELOPMENT OF THE THERMAL SPRAYING PROCESS FOR SURFACE COATING  

Microsoft Academic Search

Most commonly used methods of anticorrosion protection of large metal structures are painting and metal spraying. Painting is considerably cheaper than metal spraying, but the latter gives structures protection up to 20 years and reduces maintenance costs substantially. Metal spraying is typically achieved by spraying of molten zinc, aluminium or their alloys using thermal spraying technologies, such as Wire Flame

Igor A. Gorlach; Daniela Ghelase; Nelson Mandela

383

Spray drying method for large-scale and high-performance silicon negative electrodes in Li-ion batteries.  

PubMed

Nanostructured silicon electrodes have shown great potential as lithium ion battery anodes because they can address capacity fading mechanisms originating from large volume changes of silicon alloys while delivering extraordinarily large gravimetric capacities. Nonetheless, synthesis of well-defined silicon nanostructures in an industrially adaptable scale still remains as a challenge. Herein, we adopt an industrially established spray drying process to enable scalable synthesis of silicon-carbon composite particles in which silicon nanoparticles are embedded in porous carbon particles. The void space existing in the porous carbon accommodates the volume expansion of silicon and thus addresses the chronic fading mechanisms of silicon anodes. The composite electrodes exhibit excellent electrochemical performance, such as 1956 mAh/g at 0.05C rate and 91% capacity retention after 150 cycles. Moreover, the spray drying method requires only 2 s for the formation of each particle and allows a production capability of ~10 g/h even with an ultrasonic-based lab-scale equipment. This investigation suggests that established industrial processes could be adaptable to the production of battery active materials that require sophisticated nanostructures as well as large quantity syntheses. PMID:23537321

Jung, Dae Soo; Hwang, Tae Hoon; Park, Seung Bin; Choi, Jang Wook

2013-05-01

384

A Generalized Critical Velocity Window Based on Material Property for Cold Spraying by Eulerian Method  

NASA Astrophysics Data System (ADS)

In this paper, the previously developed Eulerian model (Yu et al., J Therm Spray Technol 21(3):745-752, 2012), which could well predict the critical velocity and erosion velocity, was extended to other commonly used materials such as aluminum, iron, nickel, stainless steel 316, and Inconel718 for studying the influence of material property and establishing a generalized window of critical velocity. Results show that the deformation behavior of the used materials could be classified as coordinated deformation (copper, iron, nickel) and uncoordinated deformation patterns (aluminum, stainless steel, and Inconel718). However, it was found that the steady maximum equivalent plastic strain values at the critical velocity for each material concentrate in the extent of 2.6-3.0 regardless of deformation pattern. Dimensionless analysis shows that, the calculated critical velocity increases with the increase of material characteristic velocity, and this relationship can be primarily used to predict the critical velocity.

Li, W. Y.; Yu, M.; Wang, F. F.; Yin, S.; Liao, H. L.

2014-02-01

385

Fabrication method for photovoltaic materials by chemical atomisation spray. Final report  

SciTech Connect

Acetonitrile has been shown to be a suitable carrier solvent for the preparation of thin layers of cuprous sulphide by chemical atomisation. A reactive spraying apparatus for monodispersed mist has been developed. It is claimed to be indispensible for establishing a firm relation between the characteristics of the mist and those of the films obtained. The formation of thin layers of cadmium sulphide and stannic oxide on various supports has been studied and the quality of the layers, their adhesion to the support, and the influence of the nature and temperature of the support on the reactions have been investigated. Three laboratories have participated in the evaluation of the physical characteristics of the thin layers.

Savelli, M.; LaHaye, J.; Vadel, J.

1982-09-01

386

Pyrolysis System and Process.  

National Technical Information Service (NTIS)

A pyrolysis system and process for recovering energy from solid waste and other feedstocks containing hydrocarbons such as coal, asphalt, naphtha, cheap crude oils, etc. is described. The process is comprised of the following steps: continuously feeding t...

S. I. Cheng

1975-01-01

387

Relationship between hydrous and ordinary pyrolysis.  

National Technical Information Service (NTIS)

Pyrolysis results are reviewed briefly with the intent of drawing comparisons between open, high pressure, and hydrous pyrolysis. Empirically, the degree of pyrolysis severity to form volatile products in open pyrolysis is similar to that required to form...

A. K. Burnham

1993-01-01

388

Cellulose pyrolysis kinetics: The current state of knowledge  

Microsoft Academic Search

Recent advances in experimental methods and computer modeling have shed new light on the kinetics of cellulose pyrolysis. The rich slate of reaction products that evolve when cellulose is heated implies that the pyrolysis chemistry is exceedingly complex. Nevertheless, a simple, first order, high activation energy (ca. 238 kJ\\/mol) model accurately describes the pyrolytic decomposition of an extraordinary variety of

Michael Jerry Jr. Antal; Gabor Varhegyi

1995-01-01

389

Characterization of pyrolytic carbon blacks from commercial tire pyrolysis plants  

Microsoft Academic Search

Pyrolysis of used tires yields oil and pyrolytic carbon black (CBP). The tire pyrolysis process can be performed either in vacuo or at atmospheric pressure. The CBP recovered in both processes are different from the commercial carbon blacks used in the tire fabrication. Different spectroscopic methods such as ESCA, SIMS, Auger-spectroscopy and XRD were used to characterize CBP obtained in

Hans Darmstadt; Christian Roy; Serge Kaliaguine

1995-01-01

390

Stabilization of Fast Pyrolysis Oil: Post Processing Final Report  

SciTech Connect

UOP LLC, a Honeywell Company, assembled a comprehensive team for a two-year project to demonstrate innovative methods for the stabilization of pyrolysis oil in accordance with DOE Funding Opportunity Announcement (FOA) DE-PS36-08GO98018, Biomass Fast Pyrolysis Oil (Bio-oil) Stabilization. In collaboration with NREL, PNNL, the USDA Agricultural Research Service (ARS), Pall Fuels and Chemicals, and Ensyn Corporation, UOP developed solutions to the key technical challenges outlined in the FOA. The UOP team proposed a multi-track technical approach for pyrolysis oil stabilization. Conceptually, methods for pyrolysis oil stabilization can be employed during one or both of two stages: (1) during the pyrolysis process (In Process); or (2) after condensation of the resulting vapor (Post-Process). Stabilization methods fall into two distinct classes: those that modify the chemical composition of the pyrolysis oil, making it less reactive; and those that remove destabilizing components from the pyrolysis oil. During the project, the team investigated methods from both classes that were suitable for application in each stage of the pyrolysis process. The post processing stabilization effort performed at PNNL is described in this report. The effort reported here was performed under a CRADA between PNNL and UOP, which was effective on March 13, 2009, for 2 years and was subsequently modified March 8, 2011, to extend the term to December 31, 2011.

Elliott, Douglas C.; Lee, Suh-Jane; Hart, Todd R.

2012-03-01

391

Effect of quantity of spraying solution on the properties of spray deposited fluorine doped tin oxide thin films  

Microsoft Academic Search

Thin films of fluorine doped tin oxide (F:SnO2) have been prepared using cost effective spray pyrolysis technique. Thin films of different thickness are obtained by varying quantity of spraying solution. Films of up to 1071 nm thickness have been deposited at a maximum growth rate of 3 nm\\/s. The structural, optical and electrical properties of these films have been studied.

A. A. Yadav; E. U. Masumdar; A. V. Moholkar; K. Y. Rajpure; C. H. Bhosale

2009-01-01

392

Effect of quantity of spraying solution on the properties of spray deposited fluorine doped tin oxide thin films  

Microsoft Academic Search

Thin films of fluorine doped tin oxide (F:SnO2) have been prepared using cost effective spray pyrolysis technique. Thin films of different thickness are obtained by varying quantity of spraying solution. Films of up to 1071nm thickness have been deposited at a maximum growth rate of 3nm\\/s. The structural, optical and electrical properties of these films have been studied. It is

A. A. Yadav; E. U. Masumdar; A. V. Moholkar; K. Y. Rajpure; C. H. Bhosale

2009-01-01

393

Nanocomposites Materials Generated from a Spray  

Microsoft Academic Search

The Spray Pyrolysis (SP) process has been employed at moderate temperature (470-970 K) for the synthesis of micro- and nano-particles of hydrated metal oxides and of related nanocomposites. It has been applied to iron nitrate solutions, without or with the addition of sodium chloride as a flux. After removal of the flux, nanocomposites of ferrihydrite (5Fe2O3,9H2O) \\/ hematite (a- Fe2O3)

R. F. C. Marques; J. M. A. Caiut; C. O. Paiva-Santos; S. J. L. Ribeiro; Y. Messaddeq; C. Garcia; D. Neumeyer; H. Dexpert; M. Verelst; J. Dexpert-Ghys

2009-01-01

394

Nuclear reactor containment spray testing system. [PWR  

Microsoft Academic Search

Disclosed is a method for periodic testing of a spray system in a nuclear reactor containment. The method includes injecting a gas into the spray system such that a temperature differential exists between the gas and the containment atmosphere. Scanning the gas jet discharged from the spray nozzles with infrared apparatus then provides a real-time thermal image on a monitor,

Rubin

1978-01-01

395

Metal spray tooling for composite forming  

Microsoft Academic Search

Thermal spraying methods have been mooted as a method of manufacturing tooling for many years and yet they have not made a significant in-road into this market. Generally, recent metal spraying research has focussed on the manufacture of small, high-pressure tools (for example, for automotive injection moulding tools). However, the metal spray process really lends itself to the manufacture of

D. I Wimpenny; G. J Gibbons

2003-01-01

396

Triboelectric spray ionization.  

PubMed

Triboelectric spray ionization (TESI) is a variation of electrospray ionization (ESI) using common instrumental components, including gas flow, solvent flow rate and heat, the only difference being the use of a high-voltage power supply for ESI or a static charge for TESI. The ionization of solvent or analyte is due to the electrostatic potential difference formed between the spray electrode and counter electrode. The ion source contains a pneumatic spray operated over a range of flow rates (0.15-1.5 µl/min) and gas pressures (0-100). This new design contains a standalone spray assembly and an optional metal mesh in front of the spray. There are several parameters that affect the performance during ionization of molecules including the flow rate of solvent, gas pressure, temperature, solvent acidity, distance and potential difference between emitter and counter electrode. A variable electrostatic potential can be applied for higher ionization efficiency. The new ionization method was successfully applied to solutions of various proteins under different conditions. The same charge-state distributions compared to other ESI techniques are observed for all the protein samples. The unique feature of TESI is very efficient spraying by using a natural electrostatic potential even at the potential that a human body can produce. This provides very gentle ionization efficiency of peptides and proteins in different solvents. PMID:23378087

Özdemir, Abdil; Lin, Jung-Lee; Gillig, Kent J; Chen, Chung-Hsuan

2013-02-01

397

Chemical analysis of biomass fast pyrolysis oils  

SciTech Connect

This paper reviews the development of the field of chemical analysis of biomass fast pyrolysis oils. The techniques applied to pyrolysis oil analysis are reviewed including proximate and ultimate analysis, water (moisture) analysis, and chemical component analysis by various forms of chromatography, solvent separations, and spectrophotometric analyses, like infrared and ultraviolet. Advanced analytical techniques such as nuclear magnetic resonance and molecular beam -- mass spectrometry are also discussed. This paper reviews and compares the methods and the results of the analyses. The advantages and shortcomings of the various methods applied are identified. Comparisons derived from the IEA Round Robin are incorporated.

Elliott, D.C.

1994-09-01

398

Molecular configuration and pyrolysis reactions of phenolic-novolaks.  

NASA Technical Reports Server (NTRS)

Description of a statistical method for characterizing the structure of an average phenolic-novolak prepolymer molecule in terms of the total number of phenolic nuclei that compose the molecule and the number of these nuclei that are pendent. It is only necessary to resort to experimental pyrolysis to evaluate the thermokinetic parameters for pyrolysis for the ablator. In addition, the fraction of phenolic involved in the major pyrolysis reactions can be estimated in terms of the parameters previously evaluated. It is shown that the overlapping reactions which occur during pyrolysis of a phenolic-novolak can be resolved by pyrolyzing samples with different extents of cure. It is then possible to determine the kinetic parameters for pyrolysis for the major reactions by well-known methods which often fail when reactions are not well resolved.

Winkler, E. L.; Parker, J. A.

1971-01-01

399

Vacuum Plasma Spraying Replaces Electrodeposition  

NASA Technical Reports Server (NTRS)

Vacuum plasma spraying used to fabricate large parts with complicated contours and inner structures, without uninspectable welds. Reduces time, and expense of fabrication. Wall of combustion chamber built up inside of outer nickel-alloy jacket by plasma spraying. Particles of metal sprayed partially melted in plasma gun and thrown at supersonic speed toward deposition surface. Vacuum plasma-spray produces stronger bond between the grooves and covering layer completing channels and wall of combustion chamber. In tests, bond withstood pressure of 20 kpsi, three times allowable limit by old method.

Holmes, Richard R.; Power, Chris; Burns, David H.; Daniel, Ron; Mckechnie, Timothy N.

1992-01-01

400

The effect of mixing methods and polymer infiltration and pyrolysis (PIP) cycles on the densification of silicon carbide inert matrix fuel through a polymer precursor route  

NASA Astrophysics Data System (ADS)

The effect of mixing methods on the fabrication of silicon carbide (SiC) inert matrix fuel through a polymer precursor route was investigated in order to break up the agglomerates of the SiC particles observed in earlier studies. It was found that a high energy shaker mill could effectively break up the agglomerates and thereby achieve a higher pellet density. Moreover, it was found that the pellet density depended less on the pressing pressure, when the particles are well mixed. SEM images showed cracks caused by the springback effect on pellets with a high cold pressing pressure of 600 MPa, but no signs of springback effect were observed for the 200 MPa pressed pellets. The polymer infiltration and pyrolysis (PIP) cycles were used to further increase the pellet density and close the open pores. The first PIP cycle was found to increase the theoretical density of the pellets from 81.2% to 86.0% and close ˜50% of the open pores. The pore size distribution showed that most of the remaining open pores had diameters smaller than 10 nm. The successive second PIP cycle is not as effective on either the density or the pore size distribution because the small pores present before the second PIP cycle made the infiltration process difficult.

Shih, Chunghao; Tulenko, J. S.; Baney, R. H.

2011-12-01

401

Simulations of Spray Reacting Flows in a Single Element LDI Injector With and Without Invoking an Eulerian Scalar PDF Method  

NASA Technical Reports Server (NTRS)

This paper presents the numerical simulations of the Jet-A spray reacting flow in a single element lean direct injection (LDI) injector by using the National Combustion Code (NCC) with and without invoking the Eulerian scalar probability density function (PDF) method. The flow field is calculated by using the Reynolds averaged Navier-Stokes equations (RANS and URANS) with nonlinear turbulence models, and when the scalar PDF method is invoked, the energy and compositions or species mass fractions are calculated by solving the equation of an ensemble averaged density-weighted fine-grained probability density function that is referred to here as the averaged probability density function (APDF). A nonlinear model for closing the convection term of the scalar APDF equation is used in the presented simulations and will be briefly described. Detailed comparisons between the results and available experimental data are carried out. Some positive findings of invoking the Eulerian scalar PDF method in both improving the simulation quality and reducing the computing cost are observed.

Shih, Tsan-Hsing; Liu, Nan-Suey

2012-01-01

402

Toxicity of pyrolysis gases from polytetrafluoroethylene  

NASA Technical Reports Server (NTRS)

A sample of polytetrafluoroethylene was evaluated for toxicity of pyrolysis gases, using various test conditions of the toxicity screening test method developed at the University of San Francisco. Time to death appears to be affected by the material of which the pyrolysis tube is made, with Monel tending to give longer times to death than quartz. When quartz tubes are used, time to death seems to be related to carbon monoxide concentration. When Monel tubes are used, carbon monoxide does not appear to be the principal toxicant.

Hilado, C. J.; Schneider, J. E.

1979-01-01

403

Azelastine Nasal Spray  

MedlinePLUS

Astelin® Nasal Spray ... Astepro® Nasal Spray ... Azelastine comes as a nasal spray. Azelastine usually is sprayed in each nostril two times a day. Follow the directions on your prescription label carefully, and ask ...

404

Pyrolysis of the tetra pak  

SciTech Connect

This study deals with pyrolysis of tetra pak which is widely used as an aseptic beverage packaging material. Pyrolysis experiments were carried out under inert atmosphere in a batch reactor at different temperatures and by different pyrolysis modes (one- and two-step). The yields of char, liquid and gas were quantified. Pyrolysis liquids produced were collected as three separate phases; aqueous phase, tar and polyethylene wax. Characterization of wax and the determination of the total amount of phenols in aqueous phase were performed. Chemical compositions of gas and char products relevant to fuel applications were determined. Pure aluminum can be also recovered by pyrolysis.

Korkmaz, Ahmet [Ege University, Faculty of Science, Chemistry Department, 35100 Izmir (Turkey); Yanik, Jale [Ege University, Faculty of Science, Chemistry Department, 35100 Izmir (Turkey)], E-mail: jale.yanik@ege.edu.tr; Brebu, Mihai; Vasile, Cornelia ['Petru Poni' Institute of Macromolecular Chemistry, Physical Chemistry of Polymers Laboratory, 700487 Iasi (Romania)

2009-11-15

405

Spray-formed tooling and aluminum strip  

Microsoft Academic Search

Spray forming is an advanced materials processing technology that converts a bulk liquid metal to a near-net-shape solid by depositing atomized droplets onto a suitably shaped substrate. By combining rapid solidification processing with product shape control, spray forming can reduce manufacturing costs while improving product quality. De Laval nozzles offer an alternative method to the more conventional spray nozzle designs.

McHugh

1995-01-01

406

Detection, Characterization and Classification of Biological Components in Aerosols by Time-Resolved Laser Pyrolysis Mass Spectrometry.  

National Technical Information Service (NTIS)

The original objective of the work reported here was to develop computerized pyrolysis mass spectrometry techniques for detection of biological aerosol components in general and time-resolved Carbon dioxide laser pyrolysis MS methods in particular. Since ...

H. L. Meuzelaar W. Windig

1987-01-01

407

Toxicity of pyrolysis gases from foam plastics  

NASA Technical Reports Server (NTRS)

Twenty-three samples of flexible foams and twelve samples of rigid foams were evaluated for toxicity of pyrolysis gases, using the USF toxicity screening test method. Polychloroprene among the flexible foams, and polystyrene among the rigid foams, appeared to exhibit the least toxicity under these particular test conditions.

Hilado, C. J.; Cumming, H. J.; Casey, C. J.

1980-01-01

408

Microwave-induced pyrolysis of sewage sludge  

Microsoft Academic Search

This paper describes a new method for pyrolyzing sewage sludge using a microwave furnace. It was found that if just the raw wet sludge is treated in the microwave, only drying of the sample takes place. However, if the sludge is mixed with a small amount of a suitable microwave absorber (such as the char produced in the pyrolysis itself)

J. A Menéndez; M Inguanzo; J. J Pis

2002-01-01

409

ENGINEERING BULLETIN: PYROLYSIS TREATMENT  

EPA Science Inventory

Pyrolysis is formally defined as chemical decomposition induced in organic materials by heat in the absence of oxygen. In practice, it is not possible to achieve a completely oxygen-free atmosphere; actual pyrolytic systems are operated with less than stoichiometric quantities of...

410

The Pyrolysis of Tetrafluorohydrazine.  

National Technical Information Service (NTIS)

The pyrolysis of tetrafluorohydrazine was studied in a passivated monel bulb over the temperature range 315-520C and at pressures from about 30-700 torr. The stoichiometry was confirmed by gas chromatographic analysis, and the reaction kinetics investigat...

J. B. Levy W. N. Corbin

1970-01-01

411

Resource Recovery by Pyrolysis.  

National Technical Information Service (NTIS)

While by means of the conventional pyrolysis technologies it was possible to treat one specific waste only, it is the aim of this project to develop a technology which enables to process a great number of hydrocarbonaceous industrial wastes, even in mixtu...

B. Andreas W. Birckenstaedt G. P. Bracker G. Collin G. Grigoleit

1981-01-01

412

Evaluation of optical parameters and characterization of ultrasonically sprayed MgO films by spectroscopic ellipsometry  

NASA Astrophysics Data System (ADS)

MgO is a chemically stable buffer layer and a good candidate with its unique optical and structural characteristics such as low refractive index and good lattice matching for the deposition of technologically important materials. In this work, we have produced MgO films by a low cost ultrasonic spray pyrolysis technique and tried to improve their characteristics by thermal annealing. MgO films have been obtained on glass substrates at 325 ± 5 °C and annealed at two different temperatures as 500 °C and 600 °C for 2 h. Elemental analyses have been made by energy-dispersive X-ray spectroscopy. Thicknesses, refractive indices and extinction coefficient values have been determined by spectroscopic ellipsometry technique using Cauchy-Urbach model. Band gap values of the films have been calculated using the absorbance spectra and optical method. X-ray diffraction patterns have been used to investigate the structural properties and to calculate lattice parameters. Atomic force microscope images have been taken to see the effect of thermal annealing on surface morphology. Electrical resistivity values of the films have been determined using a four-point probe set-up. As a result, annealing temperature has a strong effect on the mentioned properties and a low cost ultrasonic spray pyrolysis technique allows the production of new and alternative MgO buffer layers for technological applications.

Kurtaran, S.; Akyuz, I.; Atay, F.

2013-01-01

413

Classification of pyrolysis mass spectra by fuzzy multivariate rule induction-comparison with regression, K-nearest neighbour, neural and decision-tree methods  

Microsoft Academic Search

The fuzzy multivariate rule building expert system (FuRES) is applied to solve classification problems using two pyrolysis mass spectral data sets. The first data set contains three types of milk (from cow, goat and ewe) and the second data set contains two types of olive oils (adulterated and extra virgin). The performance of FuRES is compared with a selection of

B. K. Alsberg; R. Goodacre; J. J. Rowland; D. B. Kell

1997-01-01

414

Additives initiate selective production of chemicals from biomass pyrolysis.  

PubMed

To improve chemicals selectivity under low temperature, a new method that involves the injection of additives into biomass pyrolysis is introduced. This method allows biomass pyrolysis to achieve high selectivity to chemicals under low temperature (300°C), while nothing was obtained in typical pyrolysis under 300°C. However, by using the new method, the first liquid drop emerged at the interval between 140°C and 240°C. Adding methanol to mushroom scrap pyrolysis obtained high selectivity to acetic acid (98.33%), while adding ethyl acetate gained selectivity to methanol (65.77%) in bagasse pyrolysis and to acetone (72.51%) in corncob pyrolysis. Apart from basic chemicals, one high value-added chemical (2,3-dihydrobenzofuran) was also detected, which obtained the highest selectivity (10.33%) in corncob pyrolysis through the addition of ethyl acetate. Comparison of HZSM-5 and CaCO3 catalysis showed that benzene emerged in the liquid because of the larger degree of cracking and hydrodeoxygenation over HZSM-5. PMID:24508091

Leng, Shuai; Wang, Xinde; Wang, Lei; Qiu, Huizhe; Zhuang, Guilin; Zhong, Xing; Wang, Jianguo; Ma, Fengyun; Liu, Jingmei; Wang, Qiang

2014-03-01

415

A comprehensive aerosol spray method for the rapid photocatalytic grid area analysis of semiconductor photocatalyst thin films.  

PubMed

Indicator inks, previously shown to be capable of rapidly assessing photocatalytic activity via a novel photo-reductive mechanism, were simply applied via an aerosol spray onto commercially available pieces of Activ self-cleaning glass. Ink layers could be applied with high evenness of spread, with as little deviation as 5% upon UV-visible spectroscopic assessment of 25 equally distributed positions over a 10cmx10cm glass cut. The inks were comprised of either a resazurin (Rz) or dichloroindophenol (DCIP) redox dye with a glycerol sacrificial electron donor in an aqueous hydroxyethyl cellulose (HEC) polymer media. The photo-reduction reaction under UVA light of a single spot was monitored by UV-vis spectroscopy and digital images attained from a flat-bed scanner in tandem for both inks. The photo-reduction of Rz ink underwent a two-step kinetic process, whereby the blue redox dye was initially reduced to a pink intermediate resorufin (Rf) and subsequently reduced to a bleached form of the dye. In contrast, a simple one-step kinetic process was observed for the reduction of the light blue redox dye DCIP to its bleached intermediates. Changes in red-green-blue colour extracted from digital images of the inks were inversely proportional to the changes seen at corresponding wavelengths via UV-visible absorption spectroscopy and wholly indicative of the reaction kinetics. The photocatalytic activity areas of cuts of Activ glass, 10cmx10cm in size, were assessed using both Rz and DCIP indicator inks evenly sprayed over the films; firstly using UVA lamp light to activate the underlying Activ film (1.75mWcm(-2)) and secondly under solar conditions (2.06+/-0.14mWcm(-2)). The photo-reduction reactions were monitored solely by flat-bed digital scanning. Red-green-blue values of a generated 14x14 grid (196 positions) that covered the entire area of each film image were extracted using a custom-built program entitled RGB Extractor(C). A homogenous degradation over the 196 positions analysed for both Rz (Red colour deviation=19% UVA, 8% Solar; Green colour deviation=17% UVA, 12% Solar) and DCIP (Red colour deviation=22% UVA, 16% Solar) inks was seen in both UVA and solar experiments, demonstrating the consistency of the self-cleaning titania layer on Activ. The method presented provides a good solution for the high-throughput photocatalytic screening of a number of homogenous photocatalytically active materials simultaneously or numerous positions on a single film; both useful in assessing the homogeneity of a film or determining the best combination of reaction components to produce the optimum performance photocatalytic film. PMID:20172099

Kafizas, Andreas; Mills, Andrew; Parkin, Ivan P

2010-03-17

416

Spray plasma device, a new method to process nanostructured layers. application to deposit ZnO thin layers.  

PubMed

The aim of this paper is to present a new plasma spray device to deposit nanostructured films. In this process, aqueous droplets of a starting material, in this case, a nitrate salt, of small and uniform size produced in an aerosol generator are injected into a low pressure plasma reactor. Droplets are then submitted to the reactivity of plasma and projected against a substrate where they form the final film. The reactor is designed to reduce the turbulence that results in coalescence of the particles and affects the uniformity of the deposited films. The plasma is produced by an inductive RF generator that avoids the contamination of the layers by electrodes. The control of plasma gas composition, i.e., argon and oxygen, permits adjustment of the concentration of reactive species leading to control the stoichiometry of the deposited layers. The ability of this process to produce nano scale zinc oxide films by the use of an aqueous solution containing Zn(NO3)2 is demonstrated. The films obtained under defined experimental conditions are smooth, colorless and transparent. SEM and AFM photographs show the formation of uniform layers with 20 to 60 nm in thickness. XRD patterns of deposited films showed that preferential c-axis orientation of crystallites depends highly on the concentration of Zn(NO3)2 in the starting solution. Willamson-Hall method in accordance with AFM photographs showed that the size of crystallites ranges between 24 and 34 nm. PMID:20352774

Nikravech, Mehrdad

2010-02-01

417

Annealing-free, flexible silver nanowire-polymer composite electrodes via a continuous two-step spray-coating method  

NASA Astrophysics Data System (ADS)

For the realization of high-efficiency flexible optoelectronic devices, transparent electrodes should be fabricated through a low-temperature process and have the crucial feature of low surface roughness. In this paper, we demonstrated a two-step spray-coating method for producing large-scale, smooth and flexible silver nanowire (AgNW)-poly3,4-ethylenedioxythiophene:polystyrenesulfonate (PEDOT:PSS) composite electrodes. Without the high-temperature annealing process, the conductivity of the composite film was improved via the lamination of highly conductive PEDOT:PSS modified by dimethyl sulfoxide (DMSO). Under the room temperature process condition, we fabricated the AgNW-PEDOT:PSS composite film showing an 84.3% mean optical transmittance with a 10.76 ? sq-1 sheet resistance. The figure of merit ?TC was higher than that obtained from the indium tin oxide (ITO) films. The sheet resistance of the composite film slightly increased less than 5.3% during 200 cycles of tensile and compression folding, displaying good electromechanical flexibility for use in flexible optoelectronic applications.

Choi, Dong Yun; Kang, Hyun Wook; Sung, Hyung Jin; Kim, Sang Soo

2013-01-01

418

The synthesis and optical property of solid-state-prepared YAG:Ce phosphor by a spray-drying method  

SciTech Connect

Ce{sup 3+}-activated yttrium aluminum garnet (Y{sub 3}Al{sub 5}O{sub 12}:Ce, YAG:Ce) powder as luminescent phosphor was synthesized by the solid-state reaction method. The phase identification, microstructure and photoluminescent properties of the products were investigated by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), absorption spectrum and photoluminescence (PL) analysis. Spherical phosphor particle is considered better than irregular-shaped particle to improve PL property and application, so this phosphor was granulated into a sphere-like shape by a spray-drying device. After calcinating at 1500 deg. C for 0, 4, and 8 h, the product was identified as YAG and CeO{sub 2} phases. The CeO{sub 2} phase content is decreased by increasing the calcination time or decreasing the Ce{sup 3+} doping content. The product showed higher emission intensity resulted from more Ce{sup 3+} content and larger grain size. The product with CeO{sub 2} was found to have lower emission intensity. This paper presents the crystal structures of Rietveld refinement results of powder XRD data.

Lee, H.-M.; Cheng, C.-C. [Department of Resources Engineering, National Cheng Kung University, No. 1 University Road, Tainan 70101, Taiwan (China); Huang, C.-Y. [Department of Resources Engineering, National Cheng Kung University, No. 1 University Road, Tainan 70101, Taiwan (China)], E-mail: cyhuang@mail.ncku.edu.tw

2009-05-06

419

The effect of hygroscopicity on eddy covariance estimates of sea-spray aerosol fluxes: a comparison of high-rate and bulk correction methods  

NASA Astrophysics Data System (ADS)

The eddy covariance technique is the most direct of the methods that have been used to measure the flux of sea-spray aerosol between the ocean and atmosphere, but has been applied in only a handful of studies. However, unless the aerosol is dried before the eddy covariance measurements are made, the hygroscopic nature of sea-spray may combine with a relative humidity flux to result in a bias in the calculated aerosol flux. "Bulk" methods have been presented to account for this bias, however, they rely on assumptions of the shape of the aerosol spectra which may not be valid for near-surface measurements of sea-spray. Here we describe a method of correcting aerosol spectra for relative humidity induced size variations at the high frequency (10 Hz) measurement timescale, where counting statistics are poor and the spectral shape cannot be well represented by a simple power law. Such a correction allows the effects of hygroscopicity and relative humidity flux on the aerosol flux to be explicitly evaluated and compared to the bulk corrections, both in their original form and once reformulated to better represent the measured mean aerosol spectra. In general, the bulk corrections - particularly when reformulated for the measured mean aerosol spectra - perform relatively well, producing flux corrections of the right sign and approximate magnitude. However, there are times when the bulk methods either significantly over- or underestimate the required flux correction. We conclude that, where possible, relative humidity corrections should be made at the measurement frequency.

Sproson, D. A. J.; Brooks, I. M.; Norris, S. J.

2013-02-01

420

Pyrolysis kinetics of scrap tire rubbers. 1: Using DTG and TGA  

SciTech Connect

Tire pyrolysis kinetics was investigated to explore an economically viable design for the pyrolysis process. Derivative thermogravimetry (DTG) and thermogravimetric analysis (TGA) were found to provide valuable information on pyrolysis kinetics and mechanisms of a heterogeneous compound like scrap tire rubbers. Kinetic parameters of each compositional compound were obtained by analyzing DTG and TGA results with a series of mathematical methods proposed in this study. The pyrolysis kinetics of the scrap tire rubbers tested was well accounted for by the first-order irreversible independent reactions of three compositional compounds. The sidewall and tread rubber exhibited different thermal degradation patterns, suggesting a compositional difference between them. Isothermal pyrolysis results showed that the sidewall rubber would hardly be degraded at low temperature regions (<600 K), whereas it would be more rapidly degraded than the tread rubber at higher temperatures ({>=}746 K). Because of the shorter pyrolysis time, the higher isothermal pyrolysis temperature appeared to be more economically favorable.

Kim, S.; Park, J.K. [Univ. of Wisconsin, Madison, WI (United States); Chun, H.D. [Research Inst. of Industrial Science and Technology, Pohang (Korea, Republic of)

1995-07-01

421

Substrate system for spray forming  

DOEpatents

A substrate system for receiving a deposit of sprayed metal droplets including a movable outer substrate on which the sprayed metal droplets are deposited. The substrate system also includes an inner substrate disposed adjacent the outer substrate where the sprayed metal droplets are deposited on the outer substrate. The inner substrate includes zones of differing thermal conductivity to resist substrate layer porosity and to resist formation of large grains and coarse constituent particles in a bulk layer of the metal droplets which have accumulated on the outer substrate. A spray forming apparatus and associated method of spray forming a molten metal to form a metal product using the substrate system of the invention is also provided.

Chu, Men G. (Export, PA); Chernicoff, William P. (Harrisburg, PA)

2002-01-01

422

Substrate system for spray forming  

DOEpatents

A substrate system for receiving a deposit of sprayed metal droplets including a movable outer substrate on which the sprayed metal droplets are deposited. The substrate system also includes an inner substrate disposed adjacent the outer substrate where the sprayed metal droplets are deposited on the outer substrate. The inner substrate includes zones of differing thermal conductivity to resist substrate layer porosity and to resist formation of large grains and coarse constituent particles in a bulk layer of the metal droplets which have accumulated on the outer substrate. A spray forming apparatus and associated method of spray forming a molten metal to form a metal product using the substrate system of the invention is also provided.

Chu, Men G. (Export, PA); Chernicoff, William P. (Harrisburg, PA)

2000-01-01

423

An experimental study on synthesizing submicron MoSi 2-based coatings using electrothermal explosion ultra-high speed spraying method  

Microsoft Academic Search

The MoSi2-based coatings were synthesized on the surface of the low carbon steel substrate using electrothermal explosion ultra-high speed spraying method. Microstructure, phase structure, elements distribution and microhardness of the coatings were characterized by SEM, XRD, EDS and Vickers hardness tester, respectively. It is found that MoSi2 coating and MoSi2+MoB2 multiphase coating were in-situ formed. The coatings have compact microstructure,

Zong-de Liu; Shi-xiang Hou; Dong-yu Liu; Li-ping Zhao; Bin Li; Jing-jing Liu

2008-01-01

424

A nano-porous TiO 2 thin film coating method for dye sensitized solar cells (DSSCs) using electrostatic spraying with dye solution  

Microsoft Academic Search

The dye coloring process on a nano-porous TiO2 thin film for DSSCs was studied using an electrostatic spraying (ESS) method. In this study, dye coating experiments were performed using homemade ESS equipment. The coating patterns on the TiO2 thin film are changed by adjusting the applied voltages of the ESS system. The geometry of the coating patterns is observed by

Ji-Tae Hong; Hyunwoong Seo; Dong-Gil Lee; Jin-Ju Jang; Tae-Pung An; Hee-Je Kim

2010-01-01

425

Piezoelectric and ferroelectric properties of K 0.5Na 0.5NbO 3 ceramics synthesized by spray drying method  

Microsoft Academic Search

Potassium–sodium niobate was synthesized at 800°C for 1h using dried precursors in a powder form obtained by the spray drying method. Different samples were sintered from 1060 to 1120°C for 2h reaching a relative density as high as 96% of the theoretical value. Piezoelectric and ferroelectric properties were studied for these samples and some of the most prominent results are:

Rigoberto López; Federico González; M. P. Cruz; M. E. Villafuerte-Castrejon

426

Complete oxidation of methane and CO at low temperature over LaCoO 3 prepared by spray-freezing\\/freeze-drying method  

Microsoft Academic Search

Perovskite-type LaCoO3 oxides were prepared by spray-freezing\\/freeze-drying method using citrate precursor. The calcination temperature for a single phase of LaCoO3 could be lowered to 500°C without formation of any other oxides and the product had the highest surface area of 23.7m2\\/g. Below 500°C, this catalyst with the perovskite structure and the high surface area showed higher activity for complete oxidation

Seong Ho Lee; Joon Yeob Lee; Young Moo Park; Jung-Ho Wee; Kwan-Young Lee

2006-01-01

427

Novel method for in-flight particle temperature and velocity measurements in plasma spraying using a single CCD camera  

NASA Astrophysics Data System (ADS)

A novel, technically simple imaging system for individual, in-flight particle temperature and velocity measurements for plasma and other thermal spray processes is described. A custom double dichroic mirror is used to add spectral resolving capability to a single, black-and-white, fast-shutter digital charge coupled device (CCD) camera. The spectral double images produced by the individual in-flight particles are processed using specialized image processing algorithms. Particle temperature determination is based on two-color pyrometry, and particle velocities are measured from the length of the particle traces during known exposure times. In this paper, experimental results using the first prototype system are presented. Laboratory tests were performed using rotating pinholes to simulate in-flight particles, and plasma spraying experiments were performed with commercial, standard spraying equipment operated with Al2O3 and NiCrAlY powders. The prototype instrument can be readily used to determine velocity and temperature distributions of individual in-flight particles from the imaged region of interest of the plume. Dividing the imaged area into smaller sections, spatial distributions of particle temperature, velocity, and number of detected particles can be studied. The study aims to develop a technically simple, single imaging instrument, which can provide a visual overview of the spray plume in combination with quantitative evaluation of the most important spray particle parameters.

Vattulainen, J.; Hämäläinen, E.; Hernberg, R.; Vuoristo, P.; Mäntylä, T.

2001-03-01

428

Plasma spraying method for forming diamond and diamond-like coatings  

DOEpatents

A method and composition for the deposition of a thick layer (10) of diamond or diamond-like material. The method includes high temperature processing wherein a selected composition (12) including at least glassy carbon is heated in a direct current plasma arc device to a selected temperature above the softening point, in an inert atmosphere, and is propelled to quickly quenched on a selected substrate (20). The softened or molten composition (18) crystallizes on the substrate (20) to form a thick deposition layer (10) comprising at least a diamond or diamond-like material. The selected composition (12) includes at least glassy carbon as a primary constituent (14) and may include at least one secondary constituent (16). Preferably, the secondary constituents (16) are selected from the group consisting of at least diamond powder, boron carbide (B.sub.4 C) powder and mixtures thereof.

Holcombe, Cressie E. (Farragut, TN); Seals, Roland D. (Oak Ridge, TN); Price, R. Eugene (Knoxville, TN)

1997-01-01

429

Acidity of biomass fast pyrolysis bio-oils  

SciTech Connect

The use of the TAN method for measuring the acidity of biomass fast pyrolysis bio-oil was evaluated. Suggestions for carrying out the analysis have been made. The TAN method by ASTM D664 or D3339 can be used for measuring the acidity of fast pyrolysis bio-oils and their hydrotreating products. The main difference between the methods is that ASTM D664 is specified for higher TAN values than ASTM D3339. Special focus should be placed on the interpretation of the TAN curves because they differ significantly from those of mineral oils. The curve for bio-oils is so gentle that the automatic detection may not observe the end point properly and derivatization should be used. The acidity of fast pyrolysis bio-oils is mainly derived (60-70%) from volatile acids. Other groups of compounds in fast pyrolysis bio-oils that influence acidity include phenolics, fatty and resin acids, and hydroxy acids.

Oasmaa, Anja; Elliott, Douglas C.; Korhonen, Jaana

2010-12-17

430

In-source pyrolysis-field ionization mass spectrometry and Curie-point pyrolysis-gas chromatography\\/mass spectrometry of amino acids in humic substances and soils  

Microsoft Academic Search

With the aid of in-source pyrolysis-field ionization mass spectrometry (Py-FIMS) and Curie-point pyrolysis-gas chromatography\\/mass spectrometry (cPy-GC\\/MS) in the conventional electron impact mode, characteristic signals of 23 amino acid standards were described. Thermal and mass spectrometric fragmentation pathways of these amino acids differed with each method and complemented each other. Pyrolysis products assigned by Py-FIMS extended the range of signals for

C. Sorge; M. Schnitzer; H.-R. Schulten

1993-01-01

431

Development of an efficient transformation method by Agrobacterium tumefaciens and high throughput spray assay to identify transgenic plants for woodland strawberry (Fragaria vesca) using NPTII selection.  

PubMed

KEY MESSAGE : We developed an efficient Agrobacterium -mediated transformation method using an Ac/Ds transposon tagging construct for F. vesca and high throughput paromomycin spray assay to identify its transformants for strawberry functional genomics. Genomic resources for Rosaceae species are now readily available, including the Fragaria vesca genome, EST sequences, markers, linkage maps, and physical maps. The Rosaceae Genomic Executive Committee has promoted strawberry as a translational genomics model due to its unique biological features and transformability for fruit trait improvement. Our overall research goal is to use functional genomic and metabolic approaches to pursue high throughput gene discovery in the diploid woodland strawberry. F. vesca offers several advantages of a fleshy fruit typical of most fruit crops, short life cycle (seed to seed in 12-16 weeks), small genome size (206 Mbb/C), small plant size, self-compatibility, and many seeds per plant. We have developed an efficient Agrobacterium tumefaciens-mediated strawberry transformation method using kanamycin selection, and high throughput paromomycin spray assay to efficiently identify transgenic strawberry plants. Using our kanamycin transformation method, we were able to produce up to 98 independent kanamycin resistant insertional mutant lines using a T-DNA construct carrying an Ac/Ds transposon Launchpad system from a single transformation experiment involving inoculation of 22 leaf explants of F. vesca accession 551572 within approx. 11 weeks (from inoculation to soil). Transgenic plants with 1-2 copies of a transgene were confirmed by Southern blot analysis. Using our paromomycin spray assay, transgenic F. vesca plants were rapidly identified within 10 days after spraying. PMID:23160638

Pantazis, Christopher J; Fisk, Sarah; Mills, Kerri; Flinn, Barry S; Shulaev, Vladimir; Veilleux, Richard E; Dan, Yinghui

2013-03-01

432

Modeling CFB biomass pyrolysis reactors  

Microsoft Academic Search

Fluidized bed-fast pyrolysis of biomass is considered as having a high commercial potential for the thermal treatment of biomass.This paper mainly presents a model developed further to improvements in the understanding of the science, and capable of predicting pyrolysis yields that are in satisfactory agreement with literature data.The kinetics and endothermicity of biomass pyrolysis are reviewed from extensive TGA and

Manon Van de Velden; Jan Baeyens; Ioannis Boukis

2008-01-01

433

Thermal effects in cellulose pyrolysis: Relationship to char formation processes  

SciTech Connect

The thermochemistry of cellulose pyrolysis has been studied by a combination of differential scanning calorimetry and thermogravimetric analysis. Additionally, the vapor pressure and heat of vaporization of levoglucosan have been determined by an effusion method. The cellulose pyrolysis has been carried out under inert gas at heating rates from 0.1 to 60 K/min. The main cellulose thermal degradation pathway is endothermic, in the absence of mass transfer limitations that promote char formation. The endothermicity is estimated to be about 538 J/g of volatiles evolved. It is concluded that this endothermicity mainly reflects a latent heat requirement for vaporizing the primary tar decomposition products. Pyrolysis can be driven in the exothermic direction by char-forming processes that compete with tar-forming processes. The formation of char is estimated to be exothermic to the extent of about 2 kJ/g of char formed. Low heating rates, in concert with mass transfer limitations, serve to drive the pyrolysis in this direction. The enthalpy of cellulose pyrolysis is thus seen to be a sensitive function of the pyrolysis conditions. Pyrolysis appears to initially follow a common thermal pathway (in terms of enthalpy required per mass of volatile loss), irrespective of heating rate. Only at some finite level of conversion does the thermal trajectory of the process follow a heating rate dependent path, as significant char formation begins to occur.

Milosavljevic, I.; Oja, V.; Suuberg, E.M. [Brown Univ., Providence, RI (United States). Div. of Engineering] [Brown Univ., Providence, RI (United States). Div. of Engineering

1996-03-01

434

Pyrolysis process and apparatus  

DOEpatents

This invention discloses a process and apparatus for pyrolyzing particulate coal by heating with a particulate solid heating media in a transport reactor. The invention tends to dampen fluctuations in the flow of heating media upstream of the pyrolysis zone, and by so doing forms a substantially continuous and substantially uniform annular column of heating media flowing downwardly along the inside diameter of the reactor. The invention is particularly useful for bituminous or agglomerative type coals.

Lee, Chang-Kuei (Sewell, NJ)

1983-01-01

435

Analysis of polycyclic aromatic hydrocarbons in contaminated soil by Curie point pyrolysis coupled to gas chromatography–mass spectrometry, an alternative to conventional methods  

Microsoft Academic Search

Curie point pyrolysis gas chromatography–mass spectrometry (Py–GC–MS) has been compared with classical extraction procedures (Soxhlet, sonication, KOH digestion, microwave-assisted) followed by GC–MS analysis for the determination of polycyclic aromatic hydrocarbons (PAHs) in contaminated soil. In each case, the efficiency of the technique was examined for 16 PAHs included in the US Environmental Protection Agency Priority Pollutant List. The results indicate

S. Buco; M. Moragues; P. Doumenq; A. Noor; G. Mille

2004-01-01

436

Spray pyrolytic deposition and characterization of SnS and SnS2 thin films  

Microsoft Academic Search

The spray pyrolysis technique is employed to prepare thin films of SnS on glass substrates and SnS2 on glass as well as fluorine doped tin oxide (FTO) coated glass substrates. The pyrolysis temperatures of SnS and SnS2 are 350 °C and 275 °C, respectively. The films are found to be n-type semiconductors. The SnS thin film is amorphous, whereas the

B. Thangaraju; P. Kaliannan

2000-01-01

437

Fast pyrolysis of agricultural wastes: Characterization of pyrolysis products  

Microsoft Academic Search

This study deals with pyrolysis of three agricultural wastes (corncob, straw and oreganum stalks) at 500 °C in a fluidized bed reactor. The yields of char, liquid and gas were quantified. Pyrolysis liquids produced were in two separate phases; aqueous phase and oil. Oil yields varied between 35 and 41%, depending on biomass type, whereas the yields of aqueous phases were

Jale Yanik; Christoph Kornmayer; Mehmet Saglam; Mithat Yüksel

2007-01-01

438

Non-isothermal pyrolysis kinetics of three Turkish oil shales  

Microsoft Academic Search

A non-isothermal experimental study using thermogravimetric analysis (t.g.a.) was conducted to determine the overall kinetics of pyrolysis of three Turkish oil shales: Beypazari, Seyitömer and Himmeto?lu. The integral method was used in the analysis of the t.g.a. data to determine first-order pyrolysis kinetics. Particle sizes of 0.7, 1.3 and 2.6 mm and final temperatures of 400, 550 and 700°C were

Ö. Murat Do?an; B. Zühtü Uysal

1996-01-01

439

Application of analytical pyrolysis for wood fire protection control  

Microsoft Academic Search

The effect of two flame-retardant compositions (A-76% potassium carbonate, B-67% sulphate ammonium) on the process of thermal degradation of wood and the composition of volatile products of pyrolysis has been investigated by the thermogravimetry and analytical pyrolysis methods. It has been shown that the effect of flame retardants manifests itself in the low-temperature region with the formation of more thermally

G. Dobele; I. Urbanovich; A. Zhurins; V. Kampars; D. Meier

2007-01-01

440

Method of forming a leak proof plasma sprayed interconnection layer on an electrode of an electrochemical cell  

DOEpatents

A dense, substantially gas-tight, electrically conductive interconnection layer is formed on an electrode structure of an electrochemical cell by: (A) providing an electrode structure; (B) forming on a selected portion of the electrode surface, an interconnection layer having the general formula La.sub.1-x M.sub.x Cr.sub.1-y N.sub.y O.sub.3, where M is a dopant selected from the group of Ca, Sr, Ba, and mixtures thereof, and where N is a dopant selected from the group of Mg, Co, Ni, Al, and mixtures thereof, and where x and y are each independently about 0.075-0.25, by thermally spraying, preferably plasma arc spraying, a flux added interconnection spray powder, preferably agglomerated, the flux added powder comprising flux particles, preferably including dopant, preferably (CaO).sub.12. (Al.sub.2 O.sub.3).sub.7 flux particles including Ca and Al dopant, and LaCrO.sub.3 interconnection particles, preferably undoped LaCrO.sub.3, to form a dense and substantially gas-tight interconnection material bonded to the electrode structure by a single plasma spraying step; and, (C) heat treating the interconnection layer at from about 1200.degree. to 1350.degree. C. to further densify and heal the micro-cracks and macro-cracks of the thermally sprayed interconnection layer. The result is a substantially gas-tight, highly doped, electrically conductive interconnection material bonded to the electrode structure. The electrode structure can be an air electrode, and a solid electrolyte layer can be applied to the unselected portion of the air electrode, and further a fuel electrode can be applied to the solid electrolyte, to form an electrochemical cell for generation of electrical power.

Kuo, Lewis J. H. (Monroeville, PA); Vora, Shailesh D. (Monroeville, PA)

1995-01-01

441

Method of forming a leak proof plasma sprayed interconnection layer on an electrode of an electrochemical cell  

DOEpatents

A dense, substantially gas-tight, electrically conductive interconnection layer is formed on an electrode structure of an electrochemical cell by: (A) providing an electrode structure; (B) forming on a selected portion of the electrode surface, an interconnection layer having the general formula La{sub 1{minus}x}M{sub x}Cr{sub 1{minus}y}N{sub y}O{sub 3}, where M is a dopant selected from the group of Ca, Sr, Ba, and mixtures thereof, and where N is a dopant selected from the group of Mg, Co, Ni, Al, and mixtures thereof, and where x and y are each independently about 0.075--0.25, by thermally spraying, preferably plasma arc spraying, a flux added interconnection spray powder, preferably agglomerated, the flux added powder comprising flux particles, preferably including dopant, preferably (CaO){sub 12}(Al{sub 2}O{sub 3}){sub 7} flux particles including Ca and Al dopant, and LaCrO{sub 3} interconnection particles, preferably undoped LaCrO{sub 3}, to form a dense and substantially gas-tight interconnection material bonded to the electrode structure by a single plasma spraying step; and (C) heat treating the interconnection layer at from about 1,200 to 1,350 C to further densify and heal the micro-cracks and macro-cracks of the thermally sprayed interconnection layer. The result is a substantially gas-tight, highly doped, electrically conductive interconnection material bonded to the electrode struct