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1

Fabrication of ZnO nanorod using spray-pyrolysis and chemical bath deposition method  

SciTech Connect

ZnO thin films with nanorod structure were deposited using Ultrasonic Spray Pyrolysis method for seed growth, and Chemical Bath Deposition (CBD) for nanorod growth. High purity Zn-hydrate and Urea are used to control Ph were dissolved in ethanol and aqua bidest in Ultrasonic Spray Pyrolysis process. Glass substrate was placed above the heater plate of reaction chamber, and subsequently sprayed with the range duration of 5, 10 and 20 minutes at the temperatures of 3500 C. As for the Chemical Bath Deposition, the glass substrate with ZnO seed on the surface was immerse to Zn-hydrate, HMTA (Hexa Methylene Tetra Amine) and deionized water solution for duration of 3, 5 and 7 hour and temperatures of 600 C, washed in distilled water, dried, and annealed at 3500 C for an hour. The characterization of samples was carried out to reveal the surface morphology using Scanning Electron Microscopy (SEM). From the data, the combination of 5 minutes of Ultrasonic Spray Pyrolysis process and 3 hour of CBD has showed the best structure of nanorod. Meanwhile the longer Spraying process and CBD yield the bigger nanorod structure that have been made, and it makes the films more dense which make the nanorod collide each other and as a result produce unsymetric nanorod structure.

Ramadhani, Muhammad F., E-mail: brian@tf.itb.ac.id; Pasaribu, Maruli A. H., E-mail: brian@tf.itb.ac.id; Yuliarto, Brian, E-mail: brian@tf.itb.ac.id; Nugraha, E-mail: brian@tf.itb.ac.id [Advanced Functional Materials Laboratory, Engineering Physics Department Faculty of Industrial Technology, Institut Teknologi Bandung (Indonesia)

2014-02-24

2

Nonlinear optical characterization of ZnS thin film synthesized by chemical spray pyrolysis method  

NASA Astrophysics Data System (ADS)

ZnS thin film was prepared by Chemical Spray Pyrolysis (CSP) method. The sample was characterized by X-ray diffraction method and Z scan technique. XRD pattern showed that ZnS thin film has hexagonal structure with an average size of about 5.6nm. The nonlinear optical properties of ZnS thin film was studied by open aperture Z-Scan technique using Q-switched Nd-Yag Laser at 532nm. The Z-scan plot showed that the investigated ZnS thin film has saturable absorption behavior. The nonlinear absorption coefficient and saturation intensity were also estimated.

G, Sreeja V.; V, Sabitha P.; Anila, E. I.; R, Reshmi; John, Manu Punnan; Radhakrishnan, P.

2014-10-01

3

Synthesis of BaFe 12 O 19 Powder by Modified Coprecipitation and Spray Pyrolysis Methods  

Microsoft Academic Search

Fine barium hexaferrite (BaFe12O19) powder consisting of platelike particles with the magnetoplumbite structure, 30–60 nm in size, is synthesized at 550°C via rapid oxidation of a suspension of barium and iron(II) hydroxides with NaClO. The magnetic properties of BaFe12O19 powders prepared by modified coprecipitation and spray pyrolysis processes are described. The coercivity of fine BaFe12O19 powders is shown to be

V. V. Pankov

2004-01-01

4

Ethylene Glycol Assisted Synthesis of Fluorine Doped Tin Oxide Nanorods Using Improved Spray Pyrolysis Deposition Method  

NASA Astrophysics Data System (ADS)

Fluorine-doped tin oxide nanorod transparent thin films were fabricated with SnCl4·5H2O, NH4F, and ethylene glycol (EG) using an improved spray pyrolysis deposition technique. The fabricated nanorods showed a low resistance of 15.3 ?/sq and a good transparency of 70.8%. The nanorods have a higher surface area than the conventionally used thin films.

Liyanage, Devinda; Mudiyanselage Navaratne Bandara, Herath; Jayaweera, Viraj; Murakami, Kenji

2013-08-01

5

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

6

Production and characterization of submicron hematite (?-Fe2O3) particles by ultrasonic spray pyrolysis method  

NASA Astrophysics Data System (ADS)

The ultrasonic spray pyrolysis (USP) method has been used to prepare submicron hematite (?-Fe2O3) particles using two different industrial pickling solutions of iron chloride (41 g/L FeCl2 and 54 g/L FeCl3) 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 FeCl2 and FeCl3 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

7

Deposition of Ni-CGO composite anodes by electrostatic assisted ultrasonic spray pyrolysis method  

SciTech Connect

Deposition of composite films of Ni and Gd-doped ceria was carried out using the electrostatic assisted ultrasonic spray pyrolysis method for the first time. The composite films were highly homogeneous, as revealed by element mapping via energy-dispersive spectrometry. Scanning electron microscope examinations revealed that deposition temperature and electric field strength had profound influence on resultant microstructure, while composition of the precursor solution had little effect. A highly porous cauliflower structure ideal for solid oxide fuel cell anode performance was obtained with a deposition temperature of 450 deg. C under an electric field introduced by an applied voltage of 12 kV. Films obtained with a lower deposition temperature of 250 deg. C or a higher applied voltage of 15 kV resulted in denser films with low porosity, while lower applied voltages of 7 or 5 kV resulted in thinner or discontinuous films due to the insufficient electrostatic attraction on the aerosol droplets. As revealed by AC impedance measurement, the area specific resistances of the Ni-CGO anode with porous cauliflower structure were rather low and a value of 0.09 {omega} cm{sup 2} at 550 deg. C was obtained.

Chen, J.-C. [Institute of Materials Science and Engineering, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China); Chang, C.-L. [Institute of Materials Science and Engineering, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China); Hsu, C.-S. [Institute of Materials Science and Engineering, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China); Hwang, B.-H. [Institute of Materials Science and Engineering, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China)]. E-mail: zorro@mail.nsysu.edu.tw

2007-09-04

8

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. PMID:23331663

2013-01-01

9

Structure and magnetic properties of manganese-zinc-ferrites prepared by spray pyrolysis method  

NASA Astrophysics Data System (ADS)

A spray pyrolysis of a water solution of iron, manganese and iron nitrates is applied to prepare Zn0.5Mn0.5Fe2O4 single-phase ferrite with a spinel-type structure. The samples are characterized by means of differential scanning calorimetry, scanning and transmission electron microscopy, X-ray diffraction, infrared and 57Fe Mössbauer spectroscopy. The mass magnetization ? and the magnetic susceptibility 1/? of the ferrites are measured as a function of temperature over the range of 78-728 K. The obtained sample contains nanoparticles with an average diameter d ?7 nm possessing MnxZnyFe3-(x+y)O4 spinel-type structure with a uniform distribution of manganese and zinc atoms over the ferrite lattice. The Curie temperature is determined to be 375 ÷ 380 K.

Kotsikau, Dzmitry; Ivanovskaya, Maria; Pankov, Vladimir; Fedotova, Yulia

2015-01-01

10

Self-assembled monolayers assisted thin film growth of aluminum doped zinc oxide by spray pyrolysis method  

NASA Astrophysics Data System (ADS)

In this work, aluminum doped zinc oxide (AZO) were deposited on pristine and self-assembled monolayer (SAM) modified glass substrates by chemical spray pyrolysis technique. The measurements of different parameters showed that modifying the surface of the glass substrates with the different SAMs resulted in excellent nucleation sites for the crystal growth of the AZO thin film. Among the different functional groups, SAMs with sbnd CH3 terminal group improves the quality of the film remarkably, while the other groups improve the quality moderately. From the results we observed that our finding suggests a novel approach of improving the quality of AZO films deposited by spray pyrolysis technique.

Aklilu, Muluken; Tai, Yian

2013-04-01

11

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

12

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

13

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

14

[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

15

CaO-based sorbents for CO2 capture prepared by ultrasonic spray pyrolysis  

E-print Network

CaO-based sorbents for CO2 capture prepared by ultrasonic spray pyrolysis Maryam Sayyah,b Brandon R. Ito,a Massoud Rostam-Abadi,c Yongqi Luc and Kenneth S. Suslick*a We report the ultrasonic spray regenerated upon hydration.17 Aerosol synthesis methods have been extensively utilized to prepare a variety

Suslick, Kenneth S.

16

Electrical, Optical and Structural Properties of Cd0.8Al0.2S Films Grown by Spray Pyrolysis Method  

NASA Astrophysics Data System (ADS)

Cd0.8Al0.2S thin films were grown by spray pyrolysis method onto pyrex glass substrate at temperature 350° C. The electrical resistivity were found to be 9.8 × 109 W-cm and the optical band gap of the films was found to have two values of 2.31 eV and 2.46 eV at room temperature. The crystal structure of the film were studied by x-ray powder method. The peaks in diffraction pattern of the film belong to CdS, Al2O3 and Al2S3 as hexagonal, and the other peak also belongs to monoclinic sulphur.

Ýzcý, Ferhunde; Köse, Salih

1997-10-01

17

ZnS thin films deposited by spray pyrolysis technique  

Microsoft Academic Search

ZnS thin films were prepared by spray pyrolysis technique using aqueous solutions of zinc chloride and thiourea at molar ratio of 1:1, 1:2 and 2:1. The films were characterized by XRD, FTIR, SEM and EDX. The phase composition, structure and morphology of sprayed films are controlled by both, the substrate temperature and the precursors molar ratio in the solution. The

T. Dedova; M. Krunks; O. Volobujeva; I. Oja

2005-01-01

18

Cytotoxicity of Gold Nanoparticles Prepared by Ultrasonic Spray Pyrolysis  

Microsoft Academic Search

The aim of this work was to study the cytotoxicity of different fractions of gold nanoparticles prepared by ultrasonic spray pyrolysis from gold scrap. The target cells were rat thymocytes, as a type of nonproliferating cells, and L929 mouse fibroblasts, as a type of continuous proliferating cells. Fractions 1 and 2, composed of pure gold nanoparticles, as determined by scanning

R. Rudolf; B. Friedrich; S. Stopi?; I. Anžel; S. Tomi?; M. ?oli?

2012-01-01

19

Effects of ultraviolet light on B-doped CdS thin films prepared by spray pyrolysis method using perfume atomizer  

NASA Astrophysics Data System (ADS)

Boron doped CdS thin films were deposited by spray pyrolysis method using perfume atomizer. The effects of ultraviolet light on the structural, optical and electrical properties of B-doped CdS thin films were investigated as a function of dopant concentration (B/Cd). X-ray diffraction studies showed that all samples were polycrystalline nature with hexagonal structure. It was determined that the preferred orientation of non-illuminated samples changes from (1 0 1) to (0 0 2) with B concentration. The c lattice constant of films decreases from 6.810 Å to 6.661 Å with boron doping. The XRD peak intensity increased with the illumination for almost all the samples. The lattice parameters of B-doped samples remained nearly constant after illumination. It was found that the optical transmittance, photoluminescence spectra, resistivity and carrier concentration of the B-doped samples are stable after the illumination with UV light. Also the effects of UV light on B-doped CdS/Cu2S solar cell were investigated and it was determined that photoelectrical parameters of B-doped solar cell were more durable against the UV light.

Novruzov, V. D.; Keskenler, E. F.; Tomakin, M.; Kahraman, S.; Gorur, O.

2013-09-01

20

Effect of fuel rate and annealing process of LiFePO{sub 4} cathode material for Li-ion batteries synthesized by flame spray pyrolysis method  

SciTech Connect

In this study the effect of fuel rate and annealing on particle formation of LiFePO{sub 4} as battery cathode using flame spray pyrolysis method was investigated numerically and experimentally. Numerical study was done using ANSYS FLUENT program. In experimentally, LiFePO{sub 4} was synthesized from inorganic aqueous solution followed by annealing. LPG was used as fuel and air was used as oxidizer and carrier gas. Annealing process attempted in inert atmosphere at 700°C for 240 min. Numerical result showed that the increase of fuel rate caused the increase of flame temperature. Microscopic observation using Scanning Electron Microscopy (SEM) revealed that all particles have sphere and polydisperse. Increasing fuel rate caused decreasing particle size and increasing particles crystallinity. This phenomenon attributed to the flame temperature. However, all produced particles still have more amorphous phase. Therefore, annealing needed to increase particles crystallinity. Fourier Transform Infrared (FTIR) analysis showed that all particles have PO4 function group. Increasing fuel rate led to the increase of infrared spectrum absorption corresponding to the increase of particles crystallinity. This result indicated that phosphate group vibrated easily in crystalline phase. From Electrochemical Impedance Spectroscopy (EIS) analysis, annealing can cause the increase of Li{sup +} diffusivity. The diffusivity coefficient of without and with annealing particles were 6.84399×10{sup ?10} and 8.59888×10{sup ?10} cm{sup 2} s{sup ?1}, respectively.

Halim, Abdul; Setyawan, Heru; Machmudah, Siti; Nurtono, Tantular; Winardi, Sugeng [Chemical Engineering, Sepuluh Nopember Institute of Technology, Kampus Sukolilo Surabaya Indonesia 60111 (Indonesia)

2014-02-24

21

Deposition of YBCO Thin Film by Aerosol Assisted Spray Pyrolysis Using Nitrates  

Microsoft Academic Search

Coated conductor by MOCVD shows the best Ic L performance currently, but cost reduction is still ongoing issue. R&D effort for a process capable of utilizing cheap alternative precursors were tried by many research groups but few of them showed results having potential for replacing current MOCVD. Spray pyrolysis method adopting ultrasonic atomization was tried as one of the possible

Byeong-Joo Kim; Seok-Kwan Hong; Jae-Geun Kim; Jung-Ho Kim; S. X. Dou; L. Dunlop; A. Kursumovic; J. L. MacManus-Driscoll; Hee-Gyoun Lee; Gye-Won Hong

2011-01-01

22

Metal sulfide thin films by chemical spray pyrolysis  

NASA Astrophysics Data System (ADS)

CdS, ZnS and CuS thin films were prepared by spray pyrolysis method using metal chlorides and thiourea (tu) as starting materials. Metal sulfide films form as products of thermal decomposition of complexes Cd(tu)2Cl2, Zn(tu)2Cl2 and Cu(tu)Cl(DOT)1/2H2O, originally formed in aqueous solution at precursors molar ratio 1:2. The metal-ligand bonding is thermally stable up to 220 degrees Celsius, followed by multistep degradation process of complexes. The TG/DTA analysis show similar thermal behavior of complexes up to 300 degrees Celsius with the formation of metal sulfides in this decomposition step. In air intensive oxidation processes are detected close to 400, 600 and 720 degrees Celsius for Cu, Cd and Zn complexes, respectively. The results of thermoanalytical study and XRD of sprayed films show that CdS and ZnS films could be grown at 450 degrees Celsius even in air while deposition of copper sulfide films should be performed in an inert atmosphere. High total impurities content of 10 wt% in CdS films prepared at 240 degrees Celsius is originated from the precursor and reduced to 2 wt% by increasing the growth temperature up to 400 degrees Celsius.

Krunks, Malle; Mellikov, Enn

2001-04-01

23

Investigations of AlGaN/GaN MOS-HEMT with Al2O3 deposition by ultrasonic spray pyrolysis method  

NASA Astrophysics Data System (ADS)

This work investigates Al2O3/AlGaN/GaN metal-oxide-semiconductor high electron mobility transistors (MOS-HEMTs) grown on SiC substrate by using the non-vacuum ultrasonic spray pyrolysis deposition (USPD) method. The Al2O3 was deposited as gate dielectric and surface passivation simultaneously to effectively suppress gate leakage current, enhance output current density, reduce RF drain current collapse, and improve temperature-dependent stabilities performance. The present MOS-HEMT design has shown improved device performances with respect to a Schottky-gate HEMT, including drain-source saturation current density at zero gate bias (IDSS: 337.6 mA mm?1 ? 462.9 mA mm?1), gate-voltage swing (GVS: 1.55 V ? 2.92 V), two-terminal gate-drain breakdown voltage (BVGD: ?103.8 V ? ?183.5 V), unity-gain cut-off frequency (fT: 11.3 GHz ? 17.7 GHz), maximum oscillation frequency (fmax: 14.2 GHz ? 19.1 GHz), and power added effective (P.A.E.: 25.1% ? 43.6%). The bias conditions for measuring fT and fmax of the studied MOS-HEMT (Schottky-gate HEMT) are VGS = ?2.5 (?2) V and VDS = 7 V. The corresponding VGS and VDS biases are ?2.5 (?2) V and 15 V for measuring the P.A.E. characteristic. Moreover, small capacitance-voltage (C–V) hysteresis is obtained in the Al2O3-MOS structure by using USPD. Temperature-dependent characteristics of the present designs at 300–480 K are also studied.

Chou, Bo-Yi; Hsu, Wei-Chou; Liu, Han-Yin; Lee, Ching-Sung; Wu, Yu-Sheng; Sun, Wen-Ching; Wei, Sung-Yen; Yu, Sheng-Min; Chiang, Meng-Hsueh

2015-01-01

24

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

25

Aerosol Spray Pyrolysis Synthesis of Magnetic Manganese Ferrite Particles  

Microsoft Academic Search

We describe the aerosol spray pyrolysis synthesis and subsequent properties of manganese ferrite (MnFe2O4) submicrometer particles. Various combinations of the chlorides and nitrates of manganese and iron dissolved in water were used as precursors. Typical aerosol reactor residence times were 0.5–1.5s. With insufficient reactor temperature, e.g., 650°C, porous, hollow particles with a mixture of the ferrite and the individual metal

Qiang Li; C. M. Sorensen; K. J. Klabunde; G. C. Hadjipanayis

1993-01-01

26

Copper (I) oxide powder generation by spray pyrolysis  

SciTech Connect

Copper oxide powders were prepared by the spray pyrolysis of copper nitrate solutions over a range of temperatures (400{endash}1300{degree}C) and residence times (3{endash}7 s). Phase-pure [by x-ray diffraction (XRD)] copper (I) oxide was obtained at 800{endash}1300{degree}C in an inert (nitrogen) atmosphere. The particles varied from smooth, solid spheres at 1300{degree}C to irregularly shaped and hollow particles at 800{degree}C with dense particles of Cu{sub 2}O being made only at 1000{degree}C or higher. The particles were polycrystalline with an average crystallite size of 42 nm at 800{degree}C, while at 1000{endash}1200{degree}C, the particles were single crystals. Spray-pyrolysis in forming gas (7{percent} H{sub 2}{endash}N{sub 2}) atmosphere at 500{endash}700{degree}C gave Cu while spray pyrolysis in air yielded CuO over 800{endash}1000{degree}C and a mixture of Cu{sub 2}O/CuO at 1200{degree}C. These results show that solid, phase-pure Cu{sub 2}O particles can be produced by aerosol-phase densification at temperatures below its melting point (1235{degree}C). {copyright} {ital 1996 Materials Research Society.}

Majumdar, D.; Shefelbine, T.A.; Kodas, T.T. [Center for Micro-engineered Ceramics, Department of Chemical Engineering, University of New Mexico, Albuquerque, New Mexico 87131 (United States); Glicksman, H.D. [DuPont Electronics, DuPont Company, Experimental Station Building E334, P.O. Box 80334, Wilmington, Delaware 19880 (United States)

1996-11-01

27

Fabrication of functional nanomaterials using flame assisted spray pyrolysis  

SciTech Connect

Flame assisted spray pyrolysis (FASP) is a class of synthesis method for nanomaterials fabrication. The ability to control nanomaterials characteristics and easy to be-scaled up are the main features of FASP. The crystallinity and particles size of the prepared nanomaterials can be easily controlled by variation of fuel flow rate. The precursor concentration, carrier gas flow rate, and carrier gas can be also used to control the prepared nanomaterials. Energy related nanomaterials preparation uses as the example case in FASP application. These material are yttrium aluminum garnet (YAG:Ce) and tungsten oxide (WO{sub 3}). It needs strategies to produce these materials into nano-sized order. YAG:Ce nanoparticles only can be synthesized by FASP using the urea addition. The decomposition of urea under high temperature of flame promotes the breakage of YAG:Ce particles into nanoparticles. In the preparation of WO{sub 3}, the high temperature flame can be used to gasify WO{sub 3} solid material. As a result, WO{sub 3} nanoparticles can be prepared easily. Generally, to produce nanoparticles via FASP method, the boiling point of the material is important to determine the strategy which will be used.

Purwanto, Agus, E-mail: aguspur@uns.ac.id [Chemical Engineering Department, Faculty of Engineering, Sebelas Maret University, Surakarta 632112 (Indonesia)

2014-02-24

28

Near field behavior of SnO2 particle-layer deposited on standard optical fiber by electrostatic spray pyrolysis method  

NASA Astrophysics Data System (ADS)

We report the emergent optical near field profiles from standard single mode optical fibers on the cleaved end of which were deposited particle layers of SnO2. The layers, composed of micron and sub-micron sized particles, were deposited by means of Electrostatic Spray Pyrolysis (ESP) technique. Powerful analytical tools such as Atomic Force Microscopy (AFM) and Scanning Near-field Optical Microscopy (SNOM) were used to obtain simultaneously the SnO2 layers topography and the related optical near field intensity distribution, when the fiber-substrate is illuminated by a light radiation in NIR range. We show that isolated microstructures, positioned in correspondence of the fiber core, reveal highly unusual capability of locally enhancing the collected optical near field. The observed phenomenon leads to new concepts of fiber optic chemical sensors and in fiber microsystems as well.

Cusano, A.; Pilla, P.; Consales, M.; Pisco, M.; Cutolo, A.; Buosciolo, A.; Giordano, M.

2007-04-01

29

Near field behavior of SnO(2) particle-layer deposited on standard optical fiber by electrostatic spray pyrolysis method.  

PubMed

We report the emergent optical near field profiles from standard single mode optical fibers on the cleaved end of which were deposited particle layers of SnO(2). The layers, composed of micron and sub-micron sized particles, were deposited by means of Electrostatic Spray Pyrolysis (ESP) technique. Powerful analytical tools such as Atomic Force Microscopy (AFM) and Scanning Near-field Optical Microscopy (SNOM) were used to obtain simultaneously the SnO(2) layers topography and the related optical near field intensity distribution, when the fiber-substrate is illuminated by a light radiation in NIR range. We show that isolated microstructures, positioned in correspondence of the fiber core, reveal highly unusual capability of locally enhancing the collected optical near field. The observed phenomenon leads to new concepts of fiber optic chemical sensors and in fiber microsystems as well. PMID:19532764

Cusano, A; Pilla, P; Consales, M; Pisco, M; Cutolo, A; Buosciolo, A; Giordano, M

2007-04-16

30

Structural, optical and electrical studies on CdO thin films using spray pyrolysis technique  

NASA Astrophysics Data System (ADS)

Cadmium oxide thin films with enhanced electrical property were prepared on glass substrates at the substrate temperature of 300°C by spray pyrolysis method for various precursor concentration of cadmium acetate in the spray solution. The X-ray diffraction studies revealed that the films exhibit cubic crystal structure. From the transmittance spectra it was found that the CdO thin films coated on low precursor concentration are highly transparent. Hall measurements confirmed that the semiconducting behavior of CdO with n-type electrical conductivity. Thus the results authenticate that the precursor concentration influences the structural, optical and electrical properties of the deposited films.

Sankarasubramanian, K.; Solaichamy, R.; Sethuraman, K.; Rameshbabu, R.; Ramamurthi, K.

2013-02-01

31

Physicochemical properties of fine-particle ZnFe 2 O 4 prepared by spray pyrolysis of nitrate solutions  

Microsoft Academic Search

Fine zinc ferrite (ZnFe2O4) powders uniform in morphology have been prepared by spray pyrolysis of nitrate solutions. Examination by scanning electron\\u000a microscopy showed that the powders consisted of micron- and submicron-sized polycrystalline spherical particles. The ZnFe2O4 sample prepared by pyrolysis at 1000?C had paramagnetic properties. Its crystal structure was refined by the Rietveld method\\u000a and was shown to be a

E. A. Eremina; A. E. Chekanova; A. P. Kazin; M. N. Rumyantseva; P. E. Kazin; Yu. D. Tret’yakov

2007-01-01

32

ZnS thin films deposited by spray pyrolysis technique  

NASA Astrophysics Data System (ADS)

ZnS thin films were prepared by spray pyrolysis technique using aqueous solutions of zinc chloride and thiourea at molar ratio of 1:1, 1:2 and 2:1. The films were characterized by XRD, FTIR, SEM and EDX. The phase composition, structure and morphology of sprayed films are controlled by both, the substrate temperature and the precursors molar ratio in the solution. The films deposited below 380 °C are amorphous and contain thermal decomposition residues of Zn(tu)2Cl2. Chlorine content becomes negligible at 500 °C, carbon and nitrogen in the form of zinc cyanamide are present in a trace amount up to 540 °C. Highly (002) orientated ZnS films with wurtzite structure and closely stoichiometric composition could be grown at temperatures close to 500 °C using Zn:S molar ratio of 1:2 in spray solution. The film consists of well-shaped hexagonal prisms with size of 100 nm. The spray of equimolar solution (Zn:S = 1:1) results in ZnS films with smaller grain size (25 nm) and slightly Zn-rich composition at 500 °C. Higher temperature (530 °C) is needed to grow the films with wurtzite structure. The use of Zn-rich (Zn/S > 1) solution results in the films consisting of ZnO and ZnS phases above 400 °C.

Dedova, T.; Krunks, M.; Volobujeva, O.; Oja, I.

2005-02-01

33

SnS2 Thin Film Deposition by Spray Pyrolysis  

NASA Astrophysics Data System (ADS)

Tin disulfide (SnS2) thin films have been synthesized using a simplified spray pyrolysis technique using a perfume atomizer. The films were deposited using two different solutions prepared by the dilution of SnCl2 and thiourea in distilled water and in methanol. The obtained films have a microcrystalline structure. The film deposited using methanol as the solvent is nearly stochiometric SnS2 with a spinel phase having a (001) preferential orientation. The film prepared with an aqueous solution is Sn-rich. Scanning electronic microscopy (SEM) images reveal that the film deposited with the aqueous solution is rough and is formed with large wires. However, the film deposited with methanol is dense and smooth. Conductivity measurements indicate that the aqueous solution leads to an n-type semiconductor, while methanol leads to a p-type semiconductor.

Jaber, Abdallah Yahia; Alamri, Saleh Noaiman; Aida, Mohammed Salah

2012-06-01

34

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

35

Synthesis of agglomerate-free YAG: Ce3+ phosphors by co-precipitation and low temperature spray pyrolysis  

Microsoft Academic Search

Y3?xCexAl5O12 (YAG: Ce3+) phosphor particles were prepared by a new method called co-precipitation and low temperature spray pyrolysis (CP-LTSP) with oxalic acid and ammonia as precipitant. It corresponds to the first-step chemical liquid reaction, the second step dehydration and partial decomposition of precipitation droplets at 250°C and then heating at 1100°C or above. Spherical as-prepared particles and agglomerate-free YAG: Ce3+

Shengxia Gao; Yibin Chen; Renjie Zeng

2011-01-01

36

Studies on synthetic conditions of spray pyrolysis by acids addition for development of highly active Ni-SDC cermet anode  

Microsoft Academic Search

NiO-Ce0.8Sm0.2O1.9 (SDC) composite particles were synthesized by spray pyrolysis method using the starting solutions containing the components for NiO-SDC and various amounts of nitric acid or acetic acid. It was found that the particles had the smooth surface due to the presence of the dissociated acetic acid in the starting solution and the large specific surface area due to the

Mitsunobu Kawano; Hiroyuki Yoshida; Koji Hashino; Hiroshi Ijichi; Seiichi Suda; Koichi Kawahara; Toru Inagaki

2006-01-01

37

Electrochemical insertion and extraction of lithium-ion at nano-sized LiMn 2O 4 particles prepared by a spray pyrolysis method  

Microsoft Academic Search

Nano-sized LiMn2O4 particles were prepared at 1023K by electrospray pyrolysis in which they were directly deposited on a Pt substrate in gas phase. Cyclic voltammetry gave very sharp and symmetrical redox peaks at ca. 4.0 and 4.1V vs. Li\\/Li+ owing to the insertion and extraction of lithium-ion at LiMn2O4. However, the redox peaks broadened and their peak separation in an

Takayuki Doi; Tsutomu Yahiro; Shigeto Okada; Jun-ichi Yamaki

2008-01-01

38

Spray pyrolysis of ZnO thin films for photovoltaic applications: effect of gas flow rate and solute concentration  

Microsoft Academic Search

A study has been undertaken to establish the influence of the principal process variables governing the spray pyrolysis deposition of ZnO thin films on their electrical and optical properties as pertaining to photovoltaic applications. It shows that the temperature at which optimum ZnO thin films can be deposited by spray pyrolysis using a given set of conditions of solute concentration

C. Mazon; J. Muci; A. Sa-Neto; A. Ortiz-Conde; F. J. Garcia

1991-01-01

39

Properties of CuInGaSe thin films prepared by chemical spray pyrolysis  

Microsoft Academic Search

Polycrystalline films of semiconducting Cu(In1-xGax)Se2 (CIGS) quaternary alloy, one of the promising materials for photovoltaic applications, have been prepared by means of chemical spray pyrolysis (CSP). Copper, Indium and Gallium metal chlorides and Selenourea are used as constituent elements to prepare spray solution. Single phase CIGS films with chalcopyrite structure have been successfully grown on glass substrate at 350°C. The

B. J. Babu; S. Velumani; Arturo Morales-Acevedo; R. Asomoza

2010-01-01

40

Resistance to Corrosion of Zirconia Coatings Deposited by Spray Pyrolysis in Nitrided Steel  

NASA Astrophysics Data System (ADS)

Coatings of zirconium oxide were deposited onto three types of stainless steel, AISI 316L, 2205, and tool steel AISI D2, using the ultrasonic spray pyrolysis method. The effect of the flux ratio on the process and its influence on the structure and morphology of the coatings were investigated. The coatings obtained, 600 nm thick, were characterized using x-ray diffraction, scanning electron microscopy, confocal microscopy, and atomic force microscopy. The resistance to corrosion of the coatings deposited over steel (not nitrided) and stainless steel nitrided (for 2 h at 823 K) in an ammonia atmosphere was evaluated. The zirconia coating enhances the stainless steel's resistance to corrosion, with the greatest increase in corrosion resistance being observed for tool steel. When the deposition is performed on previously nitrided stainless steel, the morphology of the surface improves and the coating is more homogeneous, which leads to an improved corrosion resistance.

Cubillos, G. I.; Olaya, J. J.; Bethencourt, M.; Cifredo, G.; Blanco, G.

2013-10-01

41

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

42

Structural, optical and electrical properties of zinc oxide thin films deposited by a spray pyrolysis technique  

NASA Astrophysics Data System (ADS)

Zinc oxide (ZnO) thin films were deposited on glass substrates by spray pyrolysis technique decomposition of zinc acetate dihydrate in an ethanol solution with 30 mL of deposition rate, the ZnO thin films were deposited at two different temperatures: 300 and 350 °C. The substrates were heated using the solar cells method. The substrate was R217102 glass, whose size was 30 × 17.5 × 1 mm3. The films exhibit a hexagonal wurtzite structure with a strong (002) preferred orientation. The higher value of crystallite size is attained for sprayed films at 350 °C, which is probably due to an improvement of the crystallinity of the films at this point. The average transmittance of obtain films is about 90%–95%, as measured by a UV—vis analyzer. The band gap energy varies from 3.265 to 3.294 eV for the deposited ZnO thin film at 300 and 350 °C, respectively. The electrical resistivity measured of our films are in the order 0.36 ?·cm.

Aoun, Yacine; Benhaoua, Boubaker; Gasmi, Brahim; Benramache, Said

2015-01-01

43

Phase control in the synthesis of yttrium oxide nano and micro-particles by flame spray pyrolysis  

E-print Network

The project synthesizes phase pure Yttria particles using flame spray pyrolysis, and to experimentally determines the effect of various process parameters like residence time, adiabatic flame temperature and precursor droplet size on the phase...

Mukundan, Mallika

2009-05-15

44

Synthesis and deposition of ZnO based particles by aerosol spray pyrolysis  

Microsoft Academic Search

Spray pyrolysis was used for the deposition of well defined submicronic to nanosize particles based on ZnO. The influence of the temperature in the range from 345 to 1165 K, solution concentration (0.004 and 1.5 mol dm?3) and the residence time on the particle morphology is discussed. X-ray diffraction, differential scanning calorimetry and scanning electron microscopy were used in particle

Olivera Miloševi?; Vladimir Gagi?; Jože Vodnik; Aleksandra Mitrovi?; Ljiljana Karanovi?; Biljana Stojanovi?

1997-01-01

45

Aerosol spray pyrolysis synthesis of water-splitting ferrites for solar hydrogen production  

Microsoft Academic Search

Aerosol spray pyrolysis (ASP) was employed for the synthesis of oxygen-deficient doped ferrite systems to be used as redox\\u000a materials for the production of solar Hydrogen from water via a two-step thermochemical water-splitting cycle. In the first\\u000a step (water splitting) the reduced state of a metal oxide is oxidized by taking oxygen from water and producing hydrogen;\\u000a in the second

Souzana Lorentzou; Christos C. Agrafiotis; Athanasios G. Konstandopoulos

2008-01-01

46

Fabrication of Ag-Sheathed Bi2223 tapes using powders produced by aerosol spray pyrolysis  

Microsoft Academic Search

Bi-2223 tapes were manufactured from a fine “two-powder” product produced by using an aerosol spray pyrolysis technique. Critical\\u000a current density of 22000 A\\/ cm2 at 77K and 0 T was achieved. Nondestructive transmission x-ray diffraction study indicated\\u000a good alignment of the superconducting grains. The texturing process of the superconducting phase was found to be nearly complete\\u000a after the first 24

Yuan-Liang Wang; W. Bian; Y. Zhu; Y. Fukumoto; H. J. Wiesmann; M. Suenaga; T. R. Thurston; K. Merken; S. Hong

1995-01-01

47

Synthesis and characterization of spherical calcia stabilized zirconia nano-powders obtained by spray pyrolysis  

Microsoft Academic Search

Fine, spherical Ca0.15Zr0.85O1.85 nano-powders were prepared by spray pyrolysis, starting from a mixed aqueous and ethylic solution of zirconium acetylacetonate and calcium acetate. The influence of solution concentration, furnace temperature, mass flow of carrier gas and voltage of precipitator on microstructure, average particles size and recovery percentage were evaluated. The powders were synthesized without sintering, and for adequate preparation conditions,

H. E Esparza-Ponce; A Reyes-Rojas; W Antúnez-Flores; M Miki-Yoshida

2003-01-01

48

Growth of ZnS thin films obtained by chemical spray pyrolysis: The influence of precursors  

Microsoft Academic Search

Thin films of zinc sulphide (ZnS) were prepared by spray pyrolysis using two mixed aqueous solutions: (a) dehydrated zinc acetate (10-2 M) and thiourea (4×10-2 M) in bidistillated water; (b) zinc chloride (10-2 M) and thiourea (4×10-2 M) in bidistillated water. The structure, surface morphology, chemical composition and optical properties of these films were investigated as a function of initial

M. C. López; J. P. Espinos; F. Martín; D. Leinen; J. R. Ramos-Barrado

2005-01-01

49

Growth and characterization of the ZnO\\/ZnS bilayer obtained by chemical spray pyrolysis  

Microsoft Academic Search

ZnO\\/ZnS bilayer antireflection coatings have been prepared by spray pyrolysis using aqueous solutions of zinc acetate and thiourea or zinc chloride and thiourea. The structure, surface morphology, chemical composition and optical transmittance of the bilayer have been examined as a function of the composition of the initial solution. X-ray photoelectron spectroscopy analysis and Ar ion-beam sputter etching was carried out

M. C. López; J. P. Espinós; D. Leinen; F. Martín; S. P. Centeno; R. Romero; J. R. Ramos-Barrado

2008-01-01

50

Growth of ZnS thin films obtained by chemical spray pyrolysis: The influence of precursors  

Microsoft Academic Search

Thin films of zinc sulphide (ZnS) were prepared by spray pyrolysis using two mixed aqueous solutions: (a) dehydrated zinc acetate (10?2M) and thiourea (4×10?2M) in bidistillated water; (b) zinc chloride (10?2M) and thiourea (4×10?2M) in bidistillated water. The structure, surface morphology, chemical composition and optical properties of these films were investigated as a function of initial (Zn:S) ratio in the

M. C. López; J. P. Espinos; F. Martín; D. Leinen; J. R. Ramos-Barrado

2005-01-01

51

An experimental and modeling investigation of particle production by spray pyrolysis using a laminar flow aerosol reactor  

SciTech Connect

The influence of operating parameters on the morphology of particles prepared by spray pyrolysis was investigated using a temperature-graded laminar flow aerosol reactor. Experimentally, zirconia particles were prepared by spray pyrolysis using an aqueous solution of zirconyl hydroxide chloride. Hollow particles were formed if the reactor temperature was high, the temperature gradient was too large, the flow rate of carrier gas was high, and the initial solute concentration was low. A numerical simulation of the pyrolysis process was developed using a combination of two previous models. The simulation results compared well with the experimental results. (c) 2000 Materials Research Society.

Lenggoro, I. Wuled [Department of Chemical Engineering, Hiroshima University, Kagamiyama 1-4-1, Higashi-Hiroshima 739-8527 Japan (Japan); Hata, Takeshi [Department of Chemical Engineering, Hiroshima University, Kagamiyama 1-4-1, Higashi-Hiroshima 739-8527 Japan (Japan); Iskandar, Ferry [Department of Chemical Engineering, Hiroshima University, Kagamiyama 1-4-1, Higashi-Hiroshima 739-8527 Japan (Japan); Lunden, Melissa M. [Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States); Okuyama, Kikuo [Department of Chemical Engineering, Hiroshima University, Kagamiyama 1-4-1, Higashi-Hiroshima 739-8527 Japan (Japan)

2000-03-01

52

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

53

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

54

Solar selective coatings based on nickel oxide obtained via spray pyrolysis.  

PubMed

The paper presents the optimization process for obtaining NiO thin layers on copper substrate for solar absorber coatings, using an inexpensive and up-scalable technique: spray pyrolysis deposition (SPD). Efficient selective coatings must present a high absorption coefficient of the incident solar irradiation, and low emission of heat. The solar selective coatings design involves tailoring the surface properties for superior optical properties. The deposition parameters were varied for maximizing the solar absorbance and minimizing the thermal emittance. The film morphology was controlled using copolymers of the maleic anhydride as additives into the precursors' solution. The structural and surface properties of the films were investigated by X-ray diffraction and atomic force microscopy, respectively. The Cu/CuO(x)/NiO solar absorber shows good values for the solar absorptance (alpha(s) = 0.95) and thermal emittance (epsilon(T) = 0.05) compared with the ones obtained by other methods employed in literature and new additives are recommended in tailoring the surface of solar selective coatings. PMID:19916443

Voinea, Mihaela; Ienei, Elena; Bogatu, Cristina; Duta, Anca

2009-07-01

55

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 (CH 3COOH. 2H IIO, pure- Merck A. R. grade) and hex hydrate aluminum chloride (AlCl 3 .6H IIO) 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

56

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; Kiran, N.; Panda, Richa; Gangrade, Mohan; Nath, R.; Ganesan, V.

2014-04-01

57

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

SciTech Connect

Ni-doped cadmium sulphide [Cd{sub 1?x}Ni{sub x}S, (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, E-mail: manjumishra.iuc@gmail.com; Gangrade, Mohan; Nath, R.; Ganesan, V. [UGC-DAE Consortium for Scientific Research, Khandawa Road, Indore 452001 (India); Ajay, Akhil [Physics Department, University of Delhi, Delhi-110007 (India); Wala, Arwa Dewas [Holkar Science College, Indore - 452001 (India); N, Kiran [Physics Department, University of Mysore, Mysore-570005 (India); Panda, Richa [AITR, Bhopal-462044 (India)

2014-04-24

58

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

59

Semiconducting properties of Tm doped Yb-ZnO films by spray pyrolysis  

NASA Astrophysics Data System (ADS)

In this work, we have investigated the structural, optical and electrical properties of rare earth co-doped zinc oxide thin films prepared by spray pyrolysis technique. X-ray diffraction has shown that the films are polycrystalline and textured with the c-axis of the wurtzite structure along the growth direction. Scanning electronic microscopy and transmission electronic microscopy were used to study the films composition and morphology. Photoluminescence measurements showed that all the films have a strong emission band at around 380 nm. Layers with electrical resistivity values as low as 5.7 × 10-2 ? cm were obtained.

Chaki, Imane; Belayachi, Azzam; El Bahraoui, Toufik; Regragui, Mohamed; Abd-Lefdil, Mohamed

2014-12-01

60

Ellipsometric studies on TiO 2 thin films synthesized by spray pyrolysis technique  

NASA Astrophysics Data System (ADS)

TiO 2 thin films were synthesized on quartz substrates at substrate temperatures of 350 °C and 450 °C by thermal spray pyrolysis technique using titanium oxy-acetyl acetonate as a precursor. The optical properties of the thin films were characterized by a Spectroscopic Ellipsometer (SE). The surface morphology of the thin films was studied using Atomic Force Microscopy (AFM). The surface roughness values obtained using AFM and SE was compared. The refractive indices of the films were computed using a point by point ellipsometric data extraction procedure. The porosity of the films were modeled from the optical data by effective medium approximation and corroborated from empirical relations. Using Forouhi-Bloomer optical dispersion model, further treatment of SE data was carried out. The experimental investigations and modeling of the data were directed towards optical benchmarking of spray pyrolyzed titania thin films.

Sundari, S. Tripura; Raut, N. C.; Mathews, Tom; Ajikumar, P. K.; Dash, S.; Tyagi, A. K.; Raj, Baldev

2011-06-01

61

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

PubMed

A new flame-assisted spray pyrolysis (FASP) reactor design is presented, which allows the use of inexpensive precursors and solvents (e.g., ethanol) for synthesis of nanoparticles (10-20 nm) with uniform characteristics. In this reactor design, a gas-assisted atomizer generates the precursor solution spray that is mixed and combusted with externally fed inexpensive fuel gases (acetylene or methane) at a defined height above the atomizing nozzle. The gaseous fuel feed can be varied to control the combustion enthalpy content of the flame and onset of particle formation. This way, the enthalpy density of the flame is decoupled from the precursor solution composition. Low enthalpy content precursor solutions are prone to synthesis of non-uniform particles (e.g., bimodal particle size distribution) by standard flame spray pyrolysis (FSP) processes. For example, metal nitrates in ethanol typically produce nanosized particles by gas-to-particle conversion along with larger particles by droplet-to-particle conversion. The present FASP design facilitates the use of such low enthalpy precursor solutions for synthesis of homogeneous nanopowders by increasing the combustion enthalpy density of the flame with low-cost, gaseous fuels. The effect of flame enthalpy density on product properties in the FASP configuration is explored by the example of Bi(2)O(3) nanoparticles produced from bismuth nitrate in ethanol. Product powders were characterized by nitrogen adsorption, X-ray diffraction, X-ray disk centrifuge, and transmission electron microscopy. Homogeneous Bi(2)O(3) nanopowders were produced both by increasing the gaseous fuel content and, most notably, by cutting the air entrainment prior to ignition of the spray. PMID:23408113

Rudin, Thomas; Wegner, Karsten; Pratsinis, Sotiris E

2011-07-01

62

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

63

ZnO films prepared by spray pyrolysis: an overview of physical properties  

NASA Astrophysics Data System (ADS)

ZnO is a versatile, wide band gap material which has found many applications and shown interesting physical properties. Thin zinc oxide films were prepared by a spray pyrolysis technique of zinc nitrate aqueous solution of different concentration between 0.02 and 1.0M(S.A.Studenikin, N.Golego, M.Cocivera, J.Appl.Phys., 1998, 83), 2104.. Influence of preparation conditions on structural, electrical and optical properties has been studied. Dense optical quality or porous films were prepared. Porous films possessed green photoluminescence (S.A.Studenikin, N.Golego, M.Cocivera, J.Appl.Phys., 1998, 84), 2287.. Conductivity of films may be reversibly changed by several orders of magnitude by annealing in hydrogen or oxygen ambient. All films exhibited a long term photoconductivity relaxation occurring over days at room temperature. The relaxation was sensitive to the oxygen partial pressure. Transient photo-Hall effect measurements. were used to extract information about both concentration and mobility changes during the relaxation. For transient analysis, an improved Laplace transform method was used. The desribed approach may be useful for studying other wide band-gap semiconductors.

Studenikin, S. A.; Golego, Nickolay; Cocivera, Michael

1998-10-01

64

Experimental Study of the Effect of Spray Medium on the Collection of Bio-Oil Produced from Biomass Fast Pyrolysis  

Microsoft Academic Search

The yield and properties of bio-oil are influenced by the species of spray medium used in the biomass fast pyrolysis. In this study, the GC-MS analysis of the whole bio-oil and of the mixture with isoparaffin and ethanol respectively gave information about the influence of spray medium on bio-oil composition. It is found that isoparaffin, compared with ethanol, has a

Xinbao Li; Shurong Wang; Qi Wang; Kaige Wang

2009-01-01

65

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

66

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

NASA Astrophysics Data System (ADS)

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.

2007-02-01

67

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

68

Properties of NiO thin films deposited by intermittent spray pyrolysis process  

NASA Astrophysics Data System (ADS)

NiO thin films have been grown on glass substrates by intermittent spray pyrolysis deposition of NiCl 2·6H 2O diluted in distilled water, using a simple "perfume atomizer". The effect of the solution molarity on their properties was studied and compared to those of NiO thin films deposited with a classical spray system. It is shown that NiO thin films crystallized in the NiO structure are achieved after deposition. Whatever the precursor molarity, the grain size is around 25-30 nm. The crystallites are preferentially oriented along the (1 1 1) direction. All the films are p-type. However, the thickness and the conductivity of the NiO films depend on the precursor contraction. By comparison with the properties of films deposited by classical spray technique, it is shown that the critical precursor concentration, which induces strong thin films properties perturbations, is higher when a perfume atomizer is used. This broader stability domain can be attributed to better chlorides decomposition during the rest time used in the perfume atomizer technique.

Reguig, B. A.; Khelil, A.; Cattin, L.; Morsli, M.; Bernède, J. C.

2007-02-01

69

Luminescence Characteristics of Eu-Doped Calcium Magnesium Chlorosilicate Phosphor Particles Prepared by Spray Pyrolysis  

NASA Astrophysics Data System (ADS)

Europium (Eu)-doped calcium magnesium chlorosilicate [Ca8Mg(SiO4)4Cl2:Eu2+] phosphor particles were prepared by spray pyrolysis and their luminescence characteristics were optimized by changing the Ca precursor type, the Eu2+ content, and the post-treatment temperature. It was found that the ratio of calcium nitrate to calcium chloride, which were used as the source of Ca and Cl, respectively, significantly affects the luminescence intensity and the particle morphology. Photoluminescence intensity was monotonically increased by increasing calcium chloride content with respect to calcium nitrate content in the spray solution due to increases in the crystallinity and phase purity of Ca8Mg(SiO4)4Cl2:Eu2+. Ca8Mg(SiO4)4Cl2:Eu2+ was gradually turned from a spherical shape to a polyhedral shape of micron size as the calcium chloride content was increased in the spray solution. The concentration quenching of Eu2+ was observed at 0.375 mol % Ca. The optimized Ca8Mg(SiO4)4Cl2:Eu2+, which showed a broad emission spectrum from 460 to 550 nm with a peak position at 502 nm, had a high brightness under the excitation by short- and long-wavelength ultraviolet lights and is expected to be successfully applied as a green phosphor for UV light emitting diodes (LEDs).

Kang, Hee Sang; Hong, Seung Kwon; Koo, Hye Young; Ju, Seo Hee; Kang, Yun Chan; Jung, Kyeong Youl; Park, Seung Bin

2006-03-01

70

Low-cost plasmonic solar cells prepared by chemical spray pyrolysis  

PubMed Central

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

Katerski, Atanas; Oja Acik, Ilona; Mikli, Valdek; Mere, Arvo; Sildos, Ilmo; Krunks, Malle

2014-01-01

71

Electrical Characterization of n-ZnO/p-Si Heterojunction Prepared by Spray Pyrolysis Technique  

NASA Astrophysics Data System (ADS)

The study reports the experimental and the electrical junction properties analysis of current-voltage characteristics of n-ZnO/p-Si heterostructures. Wide band gap semiconducting layer of n-type ZnO thin film was fabricated on p-type Si wafer with spray pyrolysis technique at 550C° to form n-ZnO/ p-Si heterojunctions. The current-voltage characteristic of the n-Zn0/ p-Si heterojunction device has been measured at room temperature in the dark and under illumination (lamp/160 W). The characteristic parameters of the structure such as barrier height, ideality factor and series resistance were determined from the current-voltage measurement.

Bedia, F. Z.; Bedia, A.; Benyoucef, B.; Hamzaoui, S.

72

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

73

Luminescence Characteristics of Eu-doped Strontium Halophosphate Phosphor Particles Prepared by Spray Pyrolysis  

NASA Astrophysics Data System (ADS)

Eu-doped strontium halophosphate phosphor particles were first prepared by spray pyrolysis from various types of precursor sources and their luminescence characteristics were investigated. Phase-pure halophosphate particles were obtained when ammonium phosphate and ammonium dihydrogen phosphate were used as phosphorous source, while halophosphate particles were not obtained using phosphoric acid. Spherical and nonaggregated particles were obtained when ammonium phosphate and ammonium dihydrogen phosphate were used. However, the particles prepared from phosphoric acid were strongly aggregated. The particles prepared from the mixture of strontium nitrate and strontium chloride as strontium and chlorine sources, had a spherical shape and are nonaggregated. The particles prepared from strontium nitrate, strontium chloride and ammonium dihydrogen phosphate had the highest PL intensity among halophosphates due to their phase purity and spherical morphology.

Lee, Jong Ho; Kang, Yun Chan; Park, Seung Bin; Park, Hee Dong

2001-05-01

74

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

PubMed Central

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

2012-01-01

75

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

76

Growth and characterization of the ZnO/ZnS bilayer obtained by chemical spray pyrolysis  

NASA Astrophysics Data System (ADS)

ZnO/ZnS bilayer antireflection coatings have been prepared by spray pyrolysis using aqueous solutions of zinc acetate and thiourea or zinc chloride and thiourea. The structure, surface morphology, chemical composition and optical transmittance of the bilayer have been examined as a function of the composition of the initial solution. X-ray photoelectron spectroscopy analysis and Ar ion-beam sputter etching was carried out to obtain a depth profile of bilayer. Neither carbon nor other by-products, which could alter the optical transmittance of the bilayer were found in either the interface or bulk. The differences between the bilayers arise from the annealing of the ZnS underlayer, as well as the precursor used to prepare it.

López, M. C.; Espinós, J. P.; Leinen, D.; Martín, F.; Centeno, S. P.; Romero, R.; Ramos-Barrado, J. R.

2008-12-01

77

Growth of ZnS thin films obtained by chemical spray pyrolysis: The influence of precursors  

NASA Astrophysics Data System (ADS)

Thin films of zinc sulphide (ZnS) were prepared by spray pyrolysis using two mixed aqueous solutions: (a) dehydrated zinc acetate (10 -2 M) and thiourea (4×10 -2 M) in bidistillated water; (b) zinc chloride (10 -2 M) and thiourea (4×10 -2 M) in bidistillated water. The structure, surface morphology, chemical composition and optical properties of these films were investigated as a function of initial (Zn:S) ratio in the solution, which varied between (1:1) and (1:6) for both solutions. This parameter was optimized in order to obtain films with a good stoichiometry, crystalline quality and high transmittance. It was found that films prepared from solution A, with a (Zn:S) ratio equal to (1:4) have the largest crystal size, smoothest surface, high optical transmittance and a (Zn/S) ratio in films equal to 0.91, as determined by XPS.

López, M. C.; Espinos, J. P.; Martín, F.; Leinen, D.; Ramos-Barrado, J. R.

2005-11-01

78

Indium Oxide Thin-Film Transistors Processed at Low Temperature via Ultrasonic Spray Pyrolysis.  

PubMed

The use of ultrasonic spray pyrolysis is demonstrated for the growth of polycrystalline, highly uniform indium oxide films at temperatures in the range of 200-300 °C in air using an aqueous In(NO3)3 precursor solution. Electrical characterization of as-deposited films by field-effect measurements reveals a strong dependence of the electron mobility on deposition temperature. Transistors fabricated at ?250 °C exhibit optimum performance with maximum electron mobility values in the range of 15-20 cm(2) V (-1) s(-1) and current on/off ratio in excess of 10(6). Structural and compositional analysis of as-grown films by means of X-ray diffraction, diffuse scattering, and X-ray photoelectron spectroscopy reveal that layers deposited at 250 °C are denser and contain a reduced amount of hydroxyl groups as compared to films grown at either lower or higher temperatures. Microstructural analysis of semiconducting films deposited at 250 °C by high resolution cross-sectional transmission electron microscopy reveals that as-grown layers are extremely thin (?7 nm) and composed of laterally large (30-60 nm) highly crystalline In2O3 domains. These unique characteristics of the In2O3 films are believed to be responsible for the high electron mobilities obtained from transistors fabricated at 250 °C. Our work demonstrates the ability to grow high quality low-dimensional In2O3 films and devices via ultrasonic spray pyrolysis over large area substrates while at the same time it provides guidelines for further material and device improvements. PMID:25490965

Faber, Hendrik; Lin, Yen-Hung; Thomas, Stuart R; Zhao, Kui; Pliatsikas, Nikos; McLachlan, Martyn A; Amassian, Aram; Patsalas, Panos A; Anthopoulos, Thomas D

2015-01-14

79

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

80

Synthesis of Nano-scaled -Al2O3 Particles by Combustion Spray Byungsei Jun1,a  

E-print Network

Synthesis of Nano-scaled -Al2O3 Particles by Combustion Spray Pyrolysis Byungsei Jun1,a Sangjin Lee@ems.psu.edu Keywords: combustion, spray pyrolysis, -Al2O3, nano, particles Abstract. Unagglomerated -Al2O3 powders concentration [7]. Here we describe a modified combustion spray pyrolysis method for synthesizing ultrafine -Al2

Messing, Gary L.

81

Thermal decomposition of thiourea complexes of Cu(I), Zn(II), and Sn(II) chlorides as precursors for the spray pyrolysis deposition of sulfide thin films  

Microsoft Academic Search

Comparative study on thermal decomposition of four thiourea–metal complexes, solid precursors for spray pyrolysis deposition (SPD) methods, had been carried out by using thermoanalytical and X-ray diffraction (XRD) methods in combination. [Cu2(tu)6]Cl2·2H2O (1), ZnCl2(tu)2 (2), Sn2Cl4(tu)5·2H2O (3), and SnCl2(tu) (4) prepared from aqueous thiourea (tu) solutions, had been decomposed in a simultaneous thermogravimetric\\/differential thermoanalytical (TG\\/DTA) apparatus, while XRD phase analysis

János Madarász; Petra Bombicz; Masayuki Okuya; Shoji Kaneko

2001-01-01

82

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

83

Chemical spray pyrolysis of ?-In2S3 thin films deposited at different temperatures  

NASA Astrophysics Data System (ADS)

In2S3 thin films were deposited onto indium tin oxide-coated glass substrates by chemical spray pyrolysis while keeping the substrates at different temperatures. The structures of the sprayed In2S3 thin films were characterized by X-ray diffraction (XFD). The quality of the thin films was determined by Raman spectroscopy. Scanning electron microscopy (SEM) and atomic force microscopy were used to explore the surface morphology and topography of the thin films, respectively. The optical band gap was determined based on optical transmission measurements. The indium sulfide phase exhibited a preferential orientation in the (0, 0, 12) crystallographic direction according to the XRD analysis. The phonon vibration modes determined by Raman spectroscopy also confirmed the presence of the In2S3 phase in our samples. According to SEM, the surface morphologies of the films were free of defects. The optical band gap energy varied from 2.82 eV to 2.95 eV.

Sall, Thierno; Marí Soucase, Bernabé; Mollar, Miguel; Hartitti, Bouchaib; Fahoume, Mounir

2015-01-01

84

Structural analysis of aerosol spray pyrolysis ZnO films exhibiting ultra low ozone detection limits at room temperature  

Microsoft Academic Search

ZnO films grown by a home-made Aerosol Spray Pyrolysis (ASP) system at 350°C have shown a characteristic columnar structure with an inhomogeneous layer structure that extends all the way to the surface. Surface morphology studies revealed grain sizes of the order of 80nm and a highly porous structure which proved catalytic for the performance as gas sensing element. Conductometric ozone

I. Kortidis; K. Moschovis; F. A. Mahmoud; G. Kiriakidis

2009-01-01

85

Gas-phase particle size distributions and lead loss during spray pyrolysis of (Bi,Pb)-Sr-Ca-Cu-O  

Microsoft Academic Search

Gas-phase particle size distributions and lead loss were measured during formation of (Bi,Pb)--Sr--Ca--Cu--O and pure PbO particles by spray pyrolysis at different temperatures. A differential mobility analyzer (DMA) in conjunction with a condensation particle counter (CPC) was used to monitor the gas-phase particle size distributions, and a Berner-type low-pressure impactor was used to obtain mass size distributions and a Berner-type

Abhijit S. Gurav; Toivo T. Kodas; Jorma Joutsensaari; Esko I. Kauppinen; Riita Zilliacus

1995-01-01

86

Role of precursors on morphology and optical properties of ZnS thin films prepared by chemical spray pyrolysis  

Microsoft Academic Search

This study investigates the effect of different growth parameters on the structural and optical properties of ZnS thin films, prepared using spray pyrolysis. The films were prepared using different Zn:S ratios (between 1:1 and 1:6) and in different growth solutions: (A), zinc chloride and thiourea and (B) dehydrated zinc acetate and thiourea, both in distilled water.By varying the Zn:S ratio

M. A. Hernández-Fenollosa; M. C. López; V. Donderis; M. Gonzalez; B. Mari; J. R. Ramos-Barrado

2008-01-01

87

Properties of NiO thin films deposited by chemical spray pyrolysis using different precursor solutions  

NASA Astrophysics Data System (ADS)

NiO thin films have been deposited by chemical spray pyrolysis using a perfume atomizer to grow the aerosol. The influence of the precursor, nickel chloride hexahydrate (NiCl 2·6H 2O), nickel nitrate hexahydrate (Ni(NO 3) 2·6H 2O), nickel hydroxide hexahydrate (Ni(OH) 2·6H 2O), nickel sulfate tetrahydrate (NiSO 4·4H 2O), on the thin films properties has been studied. In the experimental conditions used (substrate temperature 350 °C, precursor concentration 0.2-0.3 M, etc.), pure NiO thin films crystallized in the cubic phase can be achieved only with NiCl 2 and Ni(NO 3) 2 precursors. These films have been post-annealed at 425 °C for 3 h either in room atmosphere or under vacuum. If all the films are p-type, it is shown that the NiO films conductivity and optical transmittance depend on annealing process. The properties of the NiO thin films annealed under room atmosphere are not significantly modified, which is attributed to the fact that the temperature and the environment of this annealing is not very different from the experimental conditions during spray deposition. The annealing under vacuum is more efficient. This annealing being proceeded in a vacuum no better than 10 -2 Pa, it is supposed that the modifications of the NiO thin film properties, mainly the conductivity and optical transmission, are related to some interaction between residual oxygen and the films.

Cattin, L.; Reguig, B. A.; Khelil, A.; Morsli, M.; Benchouk, K.; Bernède, J. C.

2008-07-01

88

Effects of N- and N-In doping on ZnO films prepared by using ultrasonic spray pyrolysis  

NASA Astrophysics Data System (ADS)

The effects of N-doping, and N-In co-doping on ZnO films were studied by analyzing the structural, electrical, and optical properties of the films prepared by using an ultrasonic spray pyrolysis (USP) method. According to scanning electron microscopy (SEM) data, all films had very complex surface structures. Their polycrystallinity were also proven by using an X-ray diffraction method. The Hall-effect measurement showed that both the undoped and the N-doped ZnO films exhibited n-type conductivity and that the N-In co-doped ZnO film showed p-type conductivity. In the extended X-ray absorption fine structure (EXAFS) analysis, the number of oxygen atoms in the N-In codoped ZnO films was found to be larger than that in the N-doped and the undoped ZnO films. The photoluminescence spectra also showed that the N-In co-doping suppressed the concentration of oxygen vacancies in the ZnO films. Through an effective incorporation of indium atoms, more oxygen atoms seem to have been introduced into the lattice of the N-In co-doped ZnO films.

Wang, Qun; Park, Se-Jeong; Shin, Dong-Myeong; Kim, Hyung-Kook; Hwang, Yoon-Hwae; Zhang, Yiwen; Li, Xiaomin

2014-12-01

89

Hierarchical porous carbon by ultrasonic spray pyrolysis yields stable cycling in lithium-sulfur battery.  

PubMed

Utilizing the unparalleled theoretical capacity of sulfur reaching 1675 mAh/g, lithium-sulfur (Li-S) batteries have been counted as promising enablers of future lithium ion battery (LIB) applications requiring high energy densities. Nevertheless, most sulfur electrodes suffer from insufficient cycle lives originating from dissolution of lithium polysulfides. As a fundamental solution to this chronic shortcoming, herein, we introduce a hierarchical porous carbon structure in which meso- and macropores are surrounded by outer micropores. Sulfur was infiltrated mainly into the inner meso- and macropores, while the outer micropores remained empty, thus serving as a "barricade" against outward dissolution of long-chain lithium polysulfides. On the basis of this systematic design, the sulfur electrode delivered 1412 mAh/g sulfur with excellent capacity retention of 77% after 500 cycles. Also, a control study suggests that even when sulfur is loaded into the outer micropores, the robust cycling performance is preserved by engaging small sulfur crystal structures (S2-4). Furthermore, the hierarchical porous carbon was produced in ultrahigh speed by scalable spray pyrolysis. Each porous carbon particle was synthesized through 5 s of carrier gas flow in a reaction tube. PMID:25007002

Jung, Dae Soo; Hwang, Tae Hoon; Lee, Ji Hoon; Koo, Hye Young; Shakoor, Rana A; Kahraman, Ramazan; Jo, Yong Nam; Park, Min-Sik; Choi, Jang Wook

2014-08-13

90

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

91

Preparation and characterization of nanostructured nickel oxide thin films by spray pyrolysis  

NASA Astrophysics Data System (ADS)

Transparent crystalline nanostructured nickel oxide (NiO) thin films were prepared using a simple spray pyrolysis technique from hydrated nickel chloride salt solution (NiCl2·6H2O) onto glass and silicon (n-type) substrates at different temperatures (280, 320, 360, and 400 °C) and with different solution concentrations (0.025, 0.05, 0.075, and 0.1 M). Structural and morphological properties of the grown NiO films were studied using X-ray diffraction (XRD) and atomic force microscope. Optical properties and chemical analysis of the films were characterized by UV-visible absorption spectra and Fourier transform infrared spectroscopy, respectively. The XRD result showed that the deposited film has an amorphous structure when deposited at temperature of T s = 280 °C and concentration of 0.025 M. At higher temperatures ( T s = 320, 360, 400 °C) and solution concentrations (0.05, 0.075, 0.1 M), the deposited films have cubic polycrystalline structure formed with preferred orientation along (111) plane. The band gap of NiO film increases from 3.4 to 3.8 eV as the molarity decreased from 0.1 to 0.05 M.

Ismail, Raid A.; Ghafori, Sa'ad; Kadhim, Ghada A.

2013-12-01

92

Luminescent properties of ZnS:Mn films deposited by spray pyrolysis  

NASA Astrophysics Data System (ADS)

The room temperature, photoluminescent properties of manganese-doped zinc sulfide films deposited by spray pyrolysis are reported. These films were deposited on Pyrex glass substrates at atmospheric pressure using air as a carrier gas. All films were polycrystalline with a wurtzite (hexagonal) structure. The manganese doping was achieved by mixing MnCl3 with the starting solution to deposit ZnS. The photoluminescence spectra was measured at room temperature as a function of the different deposition parameters and the Mn concentration. Besides the characteristic light emission associated with Mn impurities in a ZnS matrix, a peak associated with the self-activated emission was also observed under certain deposition conditions (low substrate temperatures and/or long deposition times). The presence of chlorine impurities in the films is suggested to be associated with this emission. The Mn luminescence presents a quenching effect with the Mn concentration. This quenching effect is similar to the one reported on films deposited by other techniques. The light emission at this center has an activation energy of 0.71±0.05 eV with the deposition temperature. This energy is proposed to be related with the energy required by the Mn atoms to find a proper site during the growth process to form a Mn2+ center.

Falcony, C.; Garcia, M.; Ortiz, A.; Alonso, J. C.

1992-08-01

93

Photoelectrochemical performance of W-doped BiVO4 thin films deposited by spray pyrolysis  

NASA Astrophysics Data System (ADS)

The effects of tungsten doping and hydrogen annealing on the photoelectrochemical (PEC) performance of bismuth vanadate (BiVO4) photoanodes for solar water splitting were studied. Thin films of BiVO were deposited on indium tin oxide-coated glass slides by ultrasonic spray pyrolysis of an aqueous solution containing bismuth nitrate and vanadium oxysulfate. Tungsten doping was achieved by adding either silicotungstic acid (STA) or ammonium metatungstate (AMT) to the precursor. The 1.7- to 2.2-?m-thick films exhibited a highly porous microstructure. Undoped films that were reduced at 375°C in 3% H exhibited the largest photocurrent densities under 0.1 W cm-2 AM1.5 illumination, where photocurrent densities of up to 1.3 mA cm-2 at 0.5 V with respect to Ag/AgCl were achieved. Films doped with 1% or 5% (atomic percent) tungsten from either STA or AMT exhibited reduced PEC performance and greater sample-to-sample performance variations. Powder x-ray diffraction data indicated that the films continue to crystallize in the monoclinic polymorph at low doping levels but crystallize in the tetragonal scheelite structure at higher doping. It is surmised that the phase and morphology differences promoted by the addition of W during the deposition process reduced the PEC performance as measured by photovoltammetry.

Holland, S. Keith; Dutter, Melissa R.; Lawrence, David J.; Reisner, Barbara A.; DeVore, Thomas C.

2014-01-01

94

Spray pyrolysis deposition and photoelectrochemical properties of n-type BiOI nanoplatelet thin films.  

PubMed

Bismuth oxy-iodide is a potentially interesting visible-light-active photocatalyst; yet there is little research regarding its photoelectrochemical properties. Herein we report the synthesis of BiOI nanoplatelet photoelectrodes by spray pyrolysis on fluorine-doped tin oxide substrates at various temperatures. The films exhibited n-type conductivity, most likely due to the presence of anion vacancies, and optimized films possessed incident photon conversion efficiencies of over 20% in the visible range for the oxidation of I(-) to I(3)(-) at 0.4 V vs Ag/AgCl in acetonitrile. Visible-light photons (? > 420 nm) contributed approximately 75% of the overall photocurrent under AM1.5G illumination, illustrating their usefulness under solar light illumination. A deposition temperature of 260 °C was found to result in the best performance due to the balance of morphology, crystallinity, impurity levels, and optical absorption, leading to photocurrents of roughly 0.9 mA/cm(2) at 0.4 V vs Ag/AgCl. Although the films performed stably in acetonitrile, their performance decreased significantly upon extended exposure to water, which was apparently caused by a loss of surface iodine and subsequent formation of an insulating bismuth hydroxide layer. PMID:22891667

Hahn, Nathan T; Hoang, Son; Self, Jeffrey L; Mullins, C Buddie

2012-09-25

95

Effect of temperature on structural, optical and photoluminescence properties of polycrystalline CuInS 2 thin films prepared by spray pyrolysis  

NASA Astrophysics Data System (ADS)

Copper indium disulphide (CuInS 2), is a good absorber material for photovoltaic applications. In this work, CuInS 2 is deposited by chemical spray pyrolysis on heated glass substrates. It is observed that the film growth temperature and the ion ratio Cu/In affects the structural and optical properties of CuInS 2 thin films. This paper presents the effect of temperature on the growth (for the ion ratio Cu/In=1.25), optical and photoluminescence properties of sprayed CuInS 2 films. The XRD patterns confirm the well defined single phase composition of CuInS 2 films grown from 300 to 350 °C (at Cu/In=1.25) as optimum temperature for depositing well defined crystallites along (1 1 2) oriented CuInS 2 thin films with chalcopyrite structure. D 2d point symmetry group is associated with the CuInS 2 crystallites with energy gap of 1.53 eV at room temperature. The chemical nature and the presence of additional phases are discussed based on the EDAX measurements. The absorption coefficient of sprayed CuInS 2 films is found to be in the order of 10 5-10 6 cm -1 in the UV-visible region and the optical band gap decreases with increase in temperature. Defects-related photoluminescence properties are also discussed. CuInS 2 polycrystalline films are prepared by the cost effective method of spray pyrolysis from the aqueous solutions of copper (II) chloride, indium (III) chloride and thiourea for synthesis on heated glass substrates.

Mahendran, C.; Suriyanarayanan, N.

2010-04-01

96

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

97

Direct Synthesis of High-Brightness (CeTb)MgAl11O19 Phosphor Particles by Spray Pyrolysis with Boric Acid Flux  

NASA Astrophysics Data System (ADS)

High-brightness (CeTb)MgAl11O19 (CTMA) phosphor particles were directly prepared by high temperature spray pyrolysis. The boric acid flux added into spray solution affected the morphology and photoluminescence intensity of the CTMA phosphor. The phosphor particles prepared from spray solution with 20 wt % boric acid of the product had a spherical shape and a filled morphology at 1600°C. The phosphor particles prepared by spray pyrolysis from spray solution without flux material under reducing atmosphere at 1600°C had high photoluminescence intensities under ultraviolet. The boric acid flux improved the photoluminescence intensities of the CTMA phosphor. The maximum photoluminescence intensity of the phosphor particles prepared from spray solution with an optimum amount of added boric acid flux was 114% of that of the phosphor particles prepared from spray solution without flux material. The particles directly prepared by spray pyrolysis from spray solution with 20 wt % boric acid of the product had a pure crystal structure of the CTMA phosphor.

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

2006-01-01

98

Spray pyrolysis synthesis of particles possessing magnetic and luminescent properties: application of magnetic/luminescent particles in immunoassays  

NASA Astrophysics Data System (ADS)

Many types of fluorescent nanoparticles have been investigated as alternatives to conventional organic dyes in biochemistry. In addition, magnetic beads are another type of particle that 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 IIO 3). Measurements on a Vibrating Sample Magnetometer showed an overall paramagnetic response of these composite particles. Fluorescence spectroscopy showed spectra typical of the Eu ion in a Gd IIO 3 host; a narrow emission peak centered near 615 nm. Our synthesis method offers low-cost, high-rate synthesis allowing a wide range of biological applications of magnetic/fluorescent core/shell particles. We demonstrate an immunoassay using the magnetic and fluorescent properties of the particles for separation and detection purposes.

Dosev, D.; Nichkova, M.; Dumas, R. K.; Liu, Kai; Kennedy, I. M.

2006-01-01

99

Preparation and characterization of LiMn 2O 4 ion-sieve with high Li + adsorption rate by ultrasonic spray pyrolysis  

Microsoft Academic Search

This study presents the preparation of LiMn2O4 spinel type ion-sieves, characterization of their Li+ extraction\\/insertion rates and discussion about the effect of the particle structure and morphology on lithium adsorption rate. LiMn2O4 spinel powders were synthesized by ultrasonic spray pyrolysis and solid state reaction. LiMn2O4 powder prepared by pyrolysis has agglomerate structure and spherical shape with a very uniform morphology

Cem Özgür

2010-01-01

100

Comparison of carrier transport mechanism under UV/Vis illumination in an AZO photodetector and an AZO/p-Si heterojunction photodiode produced by spray pyrolysis  

NASA Astrophysics Data System (ADS)

In this study, Aluminum doped Zinc Oxide (AZO) layer is deposited on p-type silicon (p-Si) by spray pyrolysis method to fabricate ultraviolet-visible (UV/Vis) photodetector as Al doping process can have positive effect on the photodetector performance. Morphology, crystalline structure, and Al concentration of AZO layer are investigated by SEM, XRD, and EDX. The goal of this study is to analyze the mechanism of carrier transport by means of current-voltage characteristics under UV/Vis illumination in two cases: (a) electrodes connected to the surface of AZO layer and (b) electrodes connected to cross section of heterojunction (AZO/p-Si). Measurements indicate that the AZO/p-Si photodiode exhibits a higher photocurrent and lower photoresponse time under visible illumination with respect to AZO photodetector; while under UV illumination, the above result is inversed. Besides, the internal junction field of AZO/p-Si heterojunction plays an important role on this mechanism.

Shasti, M.; Mortezaali, A.; Dariani, R. S.

2015-01-01

101

Aerosol Spray Pyrolysis Synthesis of spinel-supported catalysts for Hydrogen Production via Solair-aided Steam Reforming of Natural Gas  

Microsoft Academic Search

o C under H2 flow. In the present study, Aerosol Spray Pyrolysis (ASP) was employed for the synthesis of such catalytic systems in one step, within very short times. The synthesis experiments took place in an aerosol reactor consisting of a stainless steel tube (? 3 in, length 40 in), heated between 350-1000 o

A. Zygogianni; S. Lorentzou; P. Dimotikalis; C. Agrafiotis; A. G. Konstandopoulos

102

Facile spray-drying/pyrolysis synthesis of core-shell structure graphite/silicon-porous carbon composite as a superior anode for Li-ion batteries  

NASA Astrophysics Data System (ADS)

A silicon/graphite/amorphous carbon (Si/C) composite with a low silicon content in a core-shell structure has been easily synthesized using a simple method based on spray drying in combination with a subsequent pyrolysis process; natural graphite serves as the core, and silicon nanoparticles, which filled in the porous carbon matrix formed from the pyrolysis of citric acid and pitch precursors, serve as the shell. The combination of the core-shell structure for the composite and porous carbon-coating layer accommodates the large volume change of the silicon during the lithium intercalation/extraction process, thus stabilizing the electrode structure during discharge/charge cycles. As an anode material, the as-obtained Si/C composite demonstrates high capacity and excellent cycle stability. An initial specific discharge capacity of approximately 723.8 mAh g-1 and a reversible specific capacity of approximately 600 mAh g-1 after 100 cycles at a constant density of 100 mA g-1 are reached, about two times the values for graphite. Due to the simple synthesis process and the excellent performance of the resulted electrode, great commercial potential is envisioned.

Li, Min; Hou, Xianhua; Sha, Yujing; Wang, Jie; Hu, Shejun; Liu, Xiang; Shao, Zongping

2014-02-01

103

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

104

Effect of Catalytic Pyrolysis Conditions Using Pulse Current Heating Method on Pyrolysis Products of Wood Biomass  

PubMed Central

The influence of catalysts on the compositions of char and pyrolysis oil obtained by pyrolysis of wood biomass with pulse current heating was studied. The effects of catalysts on product compositions were analyzed using GC-MS and TEM. The compositions of some aromatic compounds changed noticeably when using a metal oxide species as the catalyst. The coexistence or dissolution of amorphous carbon and iron oxide was observed in char pyrolyzed at 800°C with Fe3O4. Pyrolysis oil compositions changed remarkably when formed in the presence of a catalyst compared to that obtained from the uncatalyzed pyrolysis of wood meal. We observed a tendency toward an increase in the ratio of polyaromatic hydrocarbons in the pyrolysis oil composition after catalytic pyrolysis at 800°C. Pyrolysis of biomass using pulse current heating and an adequate amount of catalyst is expected to yield a higher content of specific polyaromatic compounds. PMID:25614894

Honma, Sensho; Hata, Toshimitsu; Watanabe, Takashi

2014-01-01

105

Selective detection of ammonia using spray pyrolysis deposited pure and nickel doped ZnO thin films  

NASA Astrophysics Data System (ADS)

This research paper reports the deposition of nanostructured pure and Ni-doped ZnO thin films deposited at the substrate temperature of 523 K using simple and economical spray pyrolysis technique and subsequently post annealed at 673 K in air atmosphere for 3 h. Ni-doping greatly affected the crystallographic orientation, surface morphology, roughness and room temperature sensing response. Noticeable change in the crystallite size, transmittance and electrical properties was observed. The room temperature sensing characteristics like selectivity, response recovery studies, range of detection, stability and reproducibility of the undoped and Ni-doped ZnO thin films were investigated. Especially, the sensing elements exhibited an excellent selectivity towards ammonia. A lower detection limit of 5 and 25 ppm was observed for undoped and Ni-doped ZnO thin films respectively. The upper detection range was widened to 1000 ppm for the Ni-doped film.

Mani, Ganesh Kumar; Rayappan, John Bosco Balaguru

2014-08-01

106

Synthesis of In2S3 thin films by spray pyrolysis from precursors with different [S]/[In] ratios  

NASA Astrophysics Data System (ADS)

Indium sulfide (In2S3) thin films were prepared by chemical spray pyrolysis technique from solutions with different [S]/[In] ratios on glass substrates at a constant temperature of 250 °C. Thin films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive X-ray spectroscopy (EDS), Raman spectroscopy and optical transmittance spectroscopy. All samples exhibit a polycrystalline structure with a preferential orientation along (0, 0, 12). A good stoichiometry was attained for all samples. The morphology of thin film surfaces, as seen by SEM, was dense and no cracks or pinholes were observed. Raman spectroscopy analysis shows active modes belonging to ?-ln2S3 phase. The optical transmittance in the visible range is higher than 60% and the band gap energy slightly increases with the sulfur to indium ratio, attaining a value of 2.63 eV for [S]/[In] = 4.5.

Sall, Thierno; Nafidi, A.; Marí Soucase, Bernabé; Mollar, Miguel; Hartitti, Bouchaib; Fahoume, Mounir

2014-06-01

107

Effect of annealing on the properties of Sb doped ZnO thin films prepared by spray pyrolysis technique  

NASA Astrophysics Data System (ADS)

Sb doped ZnO thin films have been deposited on glass substrate at 450°C using spray pyrolysis technique. The X-ray diffraction studies revealed that the as deposited films are polycrystalline in nature with (100) preferred orientation. Whereas the films annealed at 450° C for 6h show a preferential orientation along (101) direction. Crystallites size varies from 15.7 nm to 34.95 nm with annealing duration. The Scanning electron microscopic analysis shows the plane and smooth surface of the films. The optical properties of annealed films have shown a variation in the band gap between 3.37 eV and 3.19 eV. Transparency of as grown and annealed films decreases from 78 % to 65% respectively in the visible region. The electrical conductivity of the as grown film shows an increase in the electrical conductivity by one order of magnitude with increase in the annealing duration.

Kumar, N. Sadananda; Bangera, Kasturi V.; Shivakumar, G. K.

2014-01-01

108

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

109

One-step synthesis of bismuth molybdate catalysts via flame spray pyrolysis for the selective oxidation of propylene to acrolein.  

PubMed

Flame spray pyrolysis (FSP) of Bi(iii)- and Mo(vi)-2-ethylhexanoate dissolved in xylene resulted in various nanocrystalline bismuth molybdate phases depending on the Bi/Mo ratio. Besides ?-Bi2Mo3O12 and ?-Bi2MoO6, FSP gave direct access to the metastable ?-Bi2Mo2O9 phase with high surface area (19 m(2) g(-1)). This phase is normally only obtained at high calcination temperatures (>560 °C) resulting in lower surface areas. The ?-phase was stable up to 400 °C and showed superior catalytic performance compared to ?- and ?-phases in selective oxidation of propylene to acrolein at temperatures relevant for industrial applications (360 °C). PMID:25350295

Schuh, K; Kleist, W; Høj, M; Trouillet, V; Jensen, A D; Grunwaldt, J-D

2014-12-18

110

Morphological Control of Y2O3:Eu Phosphor Particles by Adding Polymeric Precursors in Spray Pyrolysis  

NASA Astrophysics Data System (ADS)

The Y2O3:Eu phosphor particles having a spherical shape and dense morphology were prepared by a pilot-scale spray pyrolysis process which involved the introduction of polymeric precursors in the spray solution. The Y2O3:Eu particles prepared from the solution without polymeric precursors had a hollow and fractured structures. However, the particles prepared from the solutions with citric acid and ethylene glycol had a completely spherical shape and dense morphology. The polymeric chains formed from the esterification reaction between carboxyl and alcohol groups changed the drying and decomposition stages of the droplets. The ratio of citric acid, ethylene glycol and their concentrations were critical factors in the control of the morphology of the Y2O3:Eu phosphor particles. The mean crystallite sizes of the particles prepared from solutions with and without citric acid and ethylene glycol were 49 nm and 33 nm, respectively. The maximum photoluminescence intensity of the particles prepared from the solution with suitable concentrations of citric acid and ethylene glycol was 125% of that of the particles prepared from the solution without polymeric precursors.

Sohn, Jong Rak; Kang, Yun Chan; Park, Hee Dong

2002-05-01

111

(CeTb)MgAl11O19 Phosphor Particles Prepared by Spray Pyrolysis from Spray Solution Containing Citric Acid and Ethylene Glycol  

NASA Astrophysics Data System (ADS)

(CeTb)MgAl11O19 (CTMA) phosphor particles were prepared by spray pyrolysis from polymeric precursor solutions under severe preparation conditions. Citric acid and ethylene glycol used as polymeric precursors formed as-prepared and post-treated (CeTb)MgAl11O19 phosphor particles with a spherical shape and a dense morphology. The CTMA phosphor particles prepared from polymeric precursor solutions at 1600°C had a completely spherical shape, a dense morphology, and a nonaggregated morphology after post-treatment at 1400°C. The CTMA phosphor particles prepared from the polymeric precursor solution had a lower impurity content than those prepared from a pure aqueous solution. All the phosphor particles prepared from the polymeric precursor solution had higher photoluminescence intensities than those prepared from the pure aqueous solution at all temperatures. The photoluminescence intensity of the CTMA phosphor particles prepared from the polymeric precursor solution was 108% that of the phosphor particles prepared from the pure aqueous solution at 1600°C.

Jung, Dae Soo; Hong, Seung Kwon; Ju, Seo Hee; Lee, Hyo Jin; Kang, Yun Chan

2005-07-01

112

Pyrolysis of Yttria Stabilized Zirconia and its Characterization  

E-print Network

emulsion Spray pyrolysis Salt assisted aerosol decompositionand colloidal, spray pyrolysis, salt assisted aerosolAerosol out Starting solution Vacuum Pump Fig 3.1: schematic diagram of the utilized spray

FARSHIHAGHRO, EBRAHIM

2013-01-01

113

Synthesis and characterization of nano-V2O5 by flame spray pyrolysis, and its cathodic performance in Li-ion rechargeable batteries  

NASA Astrophysics Data System (ADS)

Vanadium pentoxide (V2O5) nano-particles have been synthesized by flame spray pyrolysis method to investigate their cathodic performance in Li-ion rechargeable batteries. They were characterized by surface area (Brunauer-Emmett-Teller, BET method), scanning electron microscopy (SEM), transmission electron microscopy-energy dispersive spectrometry (TEM-EDS), selected area electron diffraction (SAED), high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) methods. Spherical, crystalline (orthorhombic) nano-V2O5 particles were produced. The electrochemical tests, including cyclic voltammetry (CV) and ac impedance spectroscopy (IS), were performed to obtain the reversibility and conductivity kinetic parameters. From IS measurements, nano film conductivity was found to be 2.42 × 10-6 S cm-1, which is 10-fold higher than the commercial micro-particle V2O5 counterparts. From spectra, it was also found that the interfacial resistance became stable after 7200 s. The impedance results indicated that the rate of reaction at the interphase was controlled by both charge transfer and diffusion processes. The cyclic voltammogram showed high reversibility rate and low polarization.

Sel, Sinem; Duygulu, Ozgur; Kadiroglu, Umit; Machin, Nesrin E.

2014-11-01

114

Nb-doped TiO2/carbon composite supports synthesized by ultrasonic spray pyrolysis for proton exchange membrane (PEM) fuel cell catalysts  

NASA Astrophysics Data System (ADS)

In this paper we report the use of both ultrasonic spray pyrolysis and microwave-assisted polyol reduction methods to synthesize Nb-doped TiO2/carbon (25 wt% Nb0.07Ti0.93O2/75 wt% carbon) composite supports and Pt0.62Pd0.38 alloy catalysts, respectively. The physicochemical properties of the synthesized supports and their Pt0.62Pd0.38 supported catalysts are evaluated using several methods including XRD, TEM, BET surface area analysis, TGA, as well as ICP-MS elemental analysis. The electronic conductivities and thermal/chemical stabilities of the supports are also evaluated with respect to their possible use as catalyst supports. Electrochemical measurements for oxygen reduction activity of the Pt0.62Pd0.38 alloy catalysts supported on oxide/carbon composites are also carried out in order to check their suitability for possible PEM fuel cell applications. The results show that 20wt%Pt0.62Pd0.38/25 wt%(Nb0.07Ti0.93O2)-75 wt%C catalysts exhibit enhanced mass activities compared to those of commercially available 48wt% Pt/C and home-made 20wt% Pt62Pd38/C catalysts.

Senevirathne, Keerthi; Neburchilov, Vladimir; Alzate, Vanesa; Baker, Ryan; Neagu, Roberto; Zhang, Jiujun; Campbell, Stephen; Ye, Siyu

2012-12-01

115

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

116

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

117

Defect-induced magnetism in undoped and Mn-doped wide band gap zinc oxide grown by aerosol spray pyrolysis  

NASA Astrophysics Data System (ADS)

We present a systemic study on the structural, optical and magnetic properties of the un-doped and Mn doped ZnO thin films grown by aerosol spray pyrolysis at different deposition times. XRD profiling has shown that the structures of the prepared products are wurtzite without any evidence of second phases. Surface morphology analysis revealed that incorporation of Mn in the ZnO matrix results in the formation of "doughnut-like" structures while the corresponding un-doped ZnO showed permeable structures only at long deposition time. Optical results demonstrated that Mn-doped ZnO nanostructures exhibited both the characteristic orange Mn2+ ion-related emission at 595 nm and a shoulder around 667 nm, denoting that the Mn ions have successfully occupied lattice positions of Zn ions. The chemical composition and charge states of the Mn ions in the doped ZnO nanostructures analysed by the EDX and XPS, also confirmed that Mn2+ ions were successfully incorporated onto zinc sites in the ZnO host crystal. With the combination of defect analysis based on PL and XPS, the effect of defects on the nature and origin of ferromagnetism through EPR was investigated. These findings suggested that zinc and oxygen defects, especially zinc interstitials and singly ionized oxygen vacancies, play a crucial role in mediating ferromagnetism in the undoped ZnO.

Motaung, D. E.; Kortidis, I.; Papadaki, D.; Nkosi, S. S.; Mhlongo, G. H.; Wesley-Smith, J.; Malgas, G. F.; Mwakikunga, B. W.; Coetsee, E.; Swart, H. C.; Kiriakidis, G.; Ray, S. S.

2014-08-01

118

Photoelectrochemical performance of W-doped BiVO4 thin-films deposited by spray pyrolysis  

NASA Astrophysics Data System (ADS)

The effect of tungsten doping and hydrogen annealing treatments on the photoelectrochemical (PEC) performance of bismuth vanadate (BiVO4) photoanodes for solar water splitting was studied. Thin films of BiVO4 were deposited on ITO-coated glass slides by ultrasonic spray pyrolysis of an aqueous solution containing bismuth nitrate and vanadium oxysulfate. Tungsten doping was achieved by adding either silicotungstic acid (STA) or ammonium metatungstate (AMT) in the aqueous precursor. The 1.7 ?m - 2.2 ?m thick films exhibited a highly porous microstructure. Undoped films that were reduced at 375 ºC in 3% H2 exhibited the largest photocurrent densities under 0.1 W cm-2 AM1.5 illumination. This performance enhancement was believed to be due to the formation of oxygen vacancies, which are shallow electron donors, in the films. Films doped with 1% or 5% tungsten from either STA or AMT exhibited reduced photoelectrochemical performance and greater sample-to-sample performance variations. Powder X-ray diffraction data of the undoped films indicated that they were comprised primarily of the monoclinic scheelite phase while unidentified phases were also present. Scanning electron microscopy showed slightly different morphology characteristics for the Wdoped films. It is surmised that the addition of W in the deposition process promoted the morphology differences and the formation of different phases, thus reducing the PEC performance of the photoanode samples. Significant PEC performance variability was also observed among films deposited using the described process.

Holland, Stephen K.; Dutter, Melissa R.; Lawrence, David J.; Reisner, Barbara A.; DeVore, Thomas C.

2013-09-01

119

Cathodoluminescent and nonlinear optical properties of undoped and erbium doped nanostructured ZnO films deposited by spray pyrolysis  

NASA Astrophysics Data System (ADS)

We have deposited zinc oxide (ZnO) and erbium doped zinc oxide (ZnO:Er) thin films on heated glass substrates using spray pyrolysis technique. The effect of erbium dopant on structural, morphological, luminescent and nonlinear optical properties was studied. The deposited films have been analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), ex situ compositional analysis (ESCA), profilometry, cathodoluminescence (CL) and third harmonic generation (THG) measurements. All films were polycrystalline, having a preferential growth orientation along the ZnO (0 0 2) plane, with a corresponding average crystallite size of less than 41 nm. Addition of erbium can effectively control the film surface morphology and its cathodoluminescent properties. The films containing low erbium concentration show a uniform surface covered with hexagonal shaped grains and a strong UV light emission intensity as well as TH response. In contrast, when the erbium doping ratio exceeds 3%, a porous surface with columnar textural growth becomes more pronounced, and a substantial reduction of the cathodoluminescent and TH response. A strong TH signal was obtained for the film with good crystalline quality at the concentration of 2%. Third order nonlinear optical susceptibility ( ?<3>) values of the studied materials were in the remarkable range of 10 -12 esu.

Lamrani, M. Alaoui; Addou, M.; Sofiani, Z.; Sahraoui, B.; Ebothé, J.; El Hichou, A.; Fellahi, N.; Bernède, J. C.; Dounia, R.

2007-09-01

120

Spray pyrolysis synthesis of MAl 2O 4:Eu 2+ (M=Ba, Sr) phosphor for UV LED excitation  

NASA Astrophysics Data System (ADS)

The UV excited green emitting Eu 2+-activated BaAl 2O 4 and SrAl 2O 4 phosphors were prepared by ultrasonic spray pyrolysis at low temperature. The morphologies of phosphors were spherical and ˜1 ?m size with non-aggregation. The BaAl 2O 4:Eu 2+ and SrAl 2O 4:Eu 2+ were efficiently excited under UV range from 320 to 370 nm, and exhibited broad band emission at about 500 and 520 nm, respectively, corresponding to the 5d-4f transition of Eu 2+. The detailed properties of crystal structure and luminescence behaviors were discussed by measurements of X-ray diffraction and photoluminescence. Phosphor conversion LEDs were fabricated by combining GaN-based 380 nm emitting UV LED as an optical pumping source with the prepared phosphors. The BaAl 2O 4:Eu 2+ phosphor LEDs showed the CIE coordinate of (0.171, 0.432) in bluish-green emission, and SrAl 2O 4:Eu 2+ phosphor LEDs showed that of (0.224, 0.518) in green emission.

Chung, Wonkeun; Jeong Yu, Hong; Hee Park, Sun; Chun, Byung-Hee; Kim, Jihyun; Hyun Kim, Sung

2011-07-01

121

Polymer and Surfactant-Templated Synthesis of Hollow and Porous ZnS Nano- and Microspheres in a Spray Pyrolysis Reactor.  

PubMed

Nanostructured zinc sulfide can provide unique photonic, electronic, and catalytic properties that are of interest for applications ranging from bioimaging to photocatalysis. Here we report an easily controllable continuous method to produce porous and hollow ZnS nano- and microspheres. We used poly(ethylene glycol) methyl ether (PEG), polyvinylpyrrolidone (PVP), ethylene oxide/propylene oxide block copolymer (Pluronic F-38), and cetyltrimethylammonium bromide (CTAB) as templates to synthesize ZnS nano- and microspheres with controlled internal morphology in a spray pyrolysis process, starting from an aqueous solution of chemical precursors and templating agents. Spherical particles were produced by droplet-to-particle conversion of droplets. Zinc acetate and thiourea, used here as precursors for ZnS, react in solution to form bis-thiourea zinc acetate (BTZA), which precipitates with the evaporation of solvent. Upon further heating, BTZA decomposes to yield ZnS. During solvent evaporation, PEG and Pluronic precipitate after BTZA, driving formation of a shell of ZnS and a hollow core. In contrast, PVP and CTAB interact strongly with BTZA and ZnS, such that the PVP and ZnS remain intermixed. After evaporation of solvent, the templating agents can be pyrolyzed at high temperature to leave behind porous or hollow ZnS microspheres composed of many much smaller nanocrystals. PMID:25547202

Sharma, Munish K; Rohani, Parham; Liu, Sha; Kaus, Mark; Swihart, Mark T

2015-01-13

122

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

123

Photoelectrochemical and structural characterization of carbon-doped In2O3 and carbon-doped WO3 films prepared via spray pyrolysis  

NASA Astrophysics Data System (ADS)

Carbon-doped In2O3 and carbon-doped WO3 films were produced using a spray pyrolysis methodology with octanoic acid as the carbon dopant source. C-doped and undoped In2O3 films showed a cubic polycrystalline In2O3 structure, and C-doped and undoped WO3 films displayed a monoclinic polycrystalline WO3 structure. C-doped In2O3 and WO3, compared to their corresponding undoped materials, showed increased absorption in the 350-550 nm range with a red shift in the band gap transition. The presence of carbonate-type species in these C-doped samples was confirmed by XPS. The photoelectrochemical activity was evaluated under near UV-visible light and visible light only irradiation conditions. Under the same irradiation conditions, C-doped In2O3 and C-doped WO3 electrodes produced greater photocurrent densities than their corresponding undoped electrodes. The C-doped In2O3 electrode exhibited photocurrent densities up to 1 mA/cm2, with 40% from visible light irradiation, and the C-doped WO3 electrode showed photocurrent densities up to 1.3 mA/cm2, with 50% from visible light irradiation. These results indicate the potential for further development of In2O3 and WO3 photocatalysts by simple wet chemical methods, and provide useful information towards understanding the structure and enhanced photoelectrochemical properties of these materials.

Sun, Yanping; Rajpura, Rina; Raftery, Daniel

2009-08-01

124

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 Co2+ 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

125

Nanofiber spraying method using a supplementary electrode  

NASA Astrophysics Data System (ADS)

Using a supplementary electrode, electrospun poly(?-carprolactone) fibers were deposited on various substrates with different electrical properties. The ability to coat the substrates was independent of the surface electric resistance of the substrates. This was due to the charge reduction of the sprayed fibers, which resulted from passing through the supplementary electrode. The sprayed fibers might find applications in smart textiles, advanced coating technology, and as biomedical wound dressings.

Kim, GeunHyung; Kim, WanDoo

2006-07-01

126

Dual acceptor doping and aging effect of p-ZnO:(Na, N) nanorod thin films by spray pyrolysis  

SciTech Connect

An attempt has been made to realize p-type ZnO by dual acceptor doping (Na-N) into ZnO thin films. Na and N doped ZnO thin films of different concentrations (0 to 8 at.%) have been grown by spray pyrolysis at 623 K. The grown films on glass substrate have been characterized by X-ray diffraction (XRD), Hall measurement, UV-Vis spectrophotometer, Photoluminescence (PL) and Energy dispersive spectroscopy (EDS) to validate the p-type conduction. The surface morphology and roughness of the ZnO:(Na, N) films are studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. Hall measurement shows that all the films exhibit p-type conductivity except for 0 at.% Na-N doped ZnO film. The obtained resistivity (5.60×10{sup ?2} ? cm) and hole concentration (3.15×10{sup 18} cm{sup ?3}) for the best dual acceptor doped film is 6 at.%. It has been predicted that (Na{sub Zn}?N{sub O}) acceptor complex is responsible for the p-type conduction. The p-type conductivity of the ZnO:(Na, N) films is stable even after 6 months. The crystallinity of the films has been studied by XRD. Energy dispersive spectroscopy (EDS) confirms the presence of Na and N in 6 at.% ZnO:(Na, N) film. Photoluminescence (PL) spectra of ZnO:(Na, N) films show NBE and deep level emissions in the UV and visible regions, respectively. The ZnO:(Na, N) films exhibit a high transmittance about 90% in the visible region.

Swapna, R., E-mail: swapna.ramella@yahoo.com, E-mail: santhoshmc@nitt.edu; Amiruddin, R., E-mail: swapna.ramella@yahoo.com, E-mail: santhoshmc@nitt.edu; Santhosh Kumar, M. C., E-mail: swapna.ramella@yahoo.com, E-mail: santhoshmc@nitt.edu [Advanced Materials Laboratory, Department of Physics, National Institute of Technology, Tiruchirappalli-620 015 (India)

2014-01-28

127

A study of the photoconductivity and thermoelectric properties of SnxSy optical semiconductor thin films deposited by the spray pyrolysis technique  

Microsoft Academic Search

In this paper, thin films of tin sulfide (SnxSy) with atomic ratios of y\\/x=0.25, 0.50, 0.75, 1.00, 1.25 and 1.50 have been prepared on a glass substrate at T=420 °C using the spray pyrolysis technique. The initial materials for the preparation of thin films were an alcoholic solution consisting of tin chloride (SnCl4.5H2O) and thiourea (CS(NH3)2). The prepared thin films

M. R. Fadavieslam; N. Shahtahmasebi; M. Rezaee-Roknabadi; M. M. Bagheri-Mohagheghi

2011-01-01

128

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

129

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

SciTech Connect

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., E-mail: rampap2k@yahoo.co.in; Babu, R. Ramesh, E-mail: rampap2k@yahoo.co.in [Crystal Growth and Thin Films Laboratory, Department of Physics, Bharathidasan University, Tiruchirappalli- 620024, Tamil Nadu (India); Ramamurthi, K. [Department of Physics and Nanotechnology, Faculty of Engineering and Technology, SRM University, Kattankulathur - 603203, Tamil Nadu (India)

2014-04-24

130

Sustained release chitosan microspheres prepared by novel spray drying methods.  

PubMed

Modified spray drying methods, especially a novel w/o/w emulsion-spray drying method, were developed to prepare chitosan microspheres with a sustained drug release pattern. Release of the model drugs cimetidine and famotidine, from the microspheres prepared by the emulsion-spray drying methods, was greatly retarded with release lasting for several hours, compared with drug loaded microspheres prepared by conventional-spray drying or emulsion methods where drug release was almost instant. The slow release of drug was partly due to the poor wetting ability of the microspheres which floated on the surface of the dissolution medium. The addition of a wetting agent increased the release rate significantly. The coating of the microspheres with gelatin decreased the rate of release of drug in the presence of wetting agents. PMID:10340219

He, P; Davis, S S; Illum, L

1999-01-01

131

Influence of optical properties of ZnO thin-films deposited by spray pyrolysis and RF magnetron sputtering on the output performance of silicon solar cell  

NASA Astrophysics Data System (ADS)

ZnO thin-films were deposited by spray pyrolysis and RF magnetron sputtering techniques. The optical reflection of these thin-films is measured using UV-Vis spectrophotometer. The measured optical reflection data is used in PC-1D simulation software to study the output performance of commercial silicon wafer-based solar cell. As far as optical performance is concerned it could be demonstrated that the sprayed ZnO thin-film under laboratory conditions show equivalent performance compared to sputtered ZnO thin-film. The influence of optical properties of 65 nm thick zinc oxide thin-films deposited by vacuum and non-vacuum techniques on quantum efficiency and IV characteristics of commercial silicon-wafer based solar cell is studied and reported here.

Tripathi, Brijesh; Patel, Malkesh; Ray, Abhijit; Kumar, Manoj

2013-05-01

132

Fabrication of highly ordered, macroporous Na2W4O13 arrays by spray pyrolysis using polystyrene colloidal crystals as templates.  

PubMed

Highly ordered, macropore arrays, that is, inverse opal structures, of Na2W4O13 were successfully synthesized by spray pyrolysis using polystyrene (PS) colloidal crystals as templates. A densely packed monolayer of monodisperse PS microspheres was deposited on a silica glass substrate by use of the Langmuir-Blodgett thin film technique. Subsequently, Na2W4O13 layers were deposited on the PS templates as a thin layer by spray pyrolysis of a 5(NH4)2O.12WO(3).5H2O-NaCl solution. The PS templates were, finally, removed by thermal treatment, generating a surface with features (inverse opal structures) located where the interstitial space of the densely hexagonal-packed PS microspheres had been. The macroporous structures obviously depended on the annealing conditions such as time and temperature. The macropores were basically hemispherical in shape and highly honeycombed arrangement, which corresponded well to the PS templates. The inverse opal textures of Na2W4O13 layer surfaces enhanced their hydrophobicity. The surfaces modified by fluoroalkylsilane (FAS) were converted from hydrophobic (water contact angle=127 degrees) to hydrophilic (30 degrees) by photocatalytic oxidation using the Na2W4O13 crystal layer. The Na2W4O13 crystals exhibited high activity for FAS photodegradation. PMID:19421472

Lee, SunHyung; Teshima, Katsuya; Fujisawa, Maki; Fujii, Syuji; Endo, Morinobu; Oishi, Shuji

2009-05-21

133

Eu-doped B2O3-ZnO-PbO glass phosphor powders with spherical shape and fine size prepared by spray pyrolysis  

NASA Astrophysics Data System (ADS)

Eu-doped B2O3-ZnO-PbO glass phosphor powders with spherical shape and fine size were directly prepared by spray pyrolysis. The glass phosphor powders prepared at a temperature of 1100°C had broad XRD peak at around 28°. One glass phosphor powder was formed from one droplet at the preparation temperature range from 900 to 1100°C. The mean size of the glass phosphor powders was 0.75 ?m. The glass transition temperature ( T g ) of the glass phosphor powders prepared by spray pyrolysis was 378.5°C. The excitation spectrum of the glass phosphor powders prepared at the optimum preparation temperature of 1100°C had bands at 362, 381, 392, 463, 525, and 532 nm. The glass phosphor powders had emission spectra with bands at 579, 614, and 653 nm. The glass phosphor powders with doping concentration of Eu of 7 wt% had the maximum photoluminescence intensity. The glass phosphor layer formed from the glass phosphor powders had high transparencies above 90%.

Hong, Seung Kwon; Koo, Hye Young; Ko, You Na; Kim, Jung Hyun; Yi, Jang Heui; Kang, Yun Chan

2010-03-01

134

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

135

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.

Glovan, Ronald J. (Butte, MT); Tierney, John C. (Butte, MT); McLean, Leroy L. (Butte, MT); Johnson, Lawrence L. (Butte, MT); Nelson, Gordon L. (Butte, MT); Lee, Ying-Ming (Butte, MT)

1996-01-01

136

Barium ferrite nanoparticles prepared directly by aerosol pyrolysis  

Microsoft Academic Search

BaFe12O19 nanoparticles, 10 nm in diameter, have been obtained by combination of two methods, the citrate precursor and the aerosol pyrolysis technique. For the first time, well-crystallised barium ferrite particles were obtained by pyrolysis of an aerosol, produced by ultrasonic frequency spraying of a barium iron citrate aqueous solution, in a tubular furnace at 1000°C, without further heat treatment. The

T González-Carreño; M. P Morales; C. J Serna

2000-01-01

137

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

138

High electron mobility thin-film transistors based on Ga2O3 grown by atmospheric ultrasonic spray pyrolysis at low temperatures  

NASA Astrophysics Data System (ADS)

We report on thin-film transistors based on Ga2O3 films grown by ultrasonic spray pyrolysis in ambient atmosphere at 400-450 °C. The elemental, electronic, optical, morphological, structural, and electrical properties of the films and devices were investigated using a range of complementary characterisation techniques, whilst the effects of post deposition annealing at higher temperature (700 °C) were also investigated. Both as-grown and post-deposition annealed Ga2O3 films are found to be slightly oxygen deficient, exceptionally smooth and exhibit a wide energy bandgap of ˜4.9 eV. Transistors based on as-deposited Ga2O3 films show n-type conductivity with the maximum electron mobility of ˜2 cm2/V s.

Thomas, Stuart R.; Adamopoulos, George; Lin, Yen-Hung; Faber, Hendrik; Sygellou, Labrini; Stratakis, Emmanuel; Pliatsikas, Nikos; Patsalas, Panos A.; Anthopoulos, Thomas D.

2014-09-01

139

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

140

Fabrication and characterization of Cu 2ZnSnS 4 thin films deposited by spray pyrolysis technique  

Microsoft Academic Search

We have investigated synthesis conditions and some properties of sprayed Cu2ZnSnS4 (CZTS) thin films in order to determine the best preparation conditions for the realization of CZTS based photovoltaic solar cells. The thin films are made by means of spraying of aqueous solutions containing copper chloride, zinc chloride, tin chloride and thiourea on heated glass substrates at various temperatures. In

N. Kamoun; H. Bouzouita; B. Rezig

2007-01-01

141

Formation of core-shell-structured Zn2SnO4-carbon microspheres with superior electrochemical properties by one-pot spray pyrolysis.  

PubMed

Core-shell structured Zn2SnO4-carbon microspheres with different carbon contents are prepared by one-pot spray pyrolysis without any further heating process. A Zn2SnO4-carbon composite microsphere is prepared from one droplet containing Zn and Sn salts and polyvinylpyrrolidone (PVP). Melted PVP moves to the outside of the composite microsphere during the drying stage of the droplet. In addition, melting of the phase separated metal salts forms the dense core. Carbonization of the phase separated PVP forms the textured and porous thick carbon shell. The discharge capacities of the core-shell structured Zn2SnO4-carbon microspheres for the 2(nd) and 120(th) cycles at a current density of 1 A g(-1) are 864 and 770 mA h g(-1), respectively. However, the discharge capacities of the bare Zn2SnO4 microspheres prepared by the same process without PVP for the 2(nd) and 120(th) cycles are 1106 and 81 mA h g(-1), respectively. The stable and reversible discharge capacities of the Zn2SnO4-carbon composite microspheres prepared from the spray solution with 15 g PVP decrease from 894 to 528 mA h g(-1) as current density increases from 0.5 to 5 A g(-1). PMID:25429709

Hong, Young Jun; Kang, Yun Chan

2015-01-14

142

Pyrolysis of Organomercury Compounds: Investigation by the Method of Matrix Isolation  

PubMed Central

The method of matrix isolation has been used to investigate mechanisms of gas-phase chemical reactions, in particular the pyrolysis of some organomercury compounds. A molecular beam of pyrolysis products was condensed simultaneously with a large excess of rare gas at temperatures from 5 to 15°K to form a matrix that was subsequently studied by infrared spectroscopy. In the case of C6H5HgCCl3, we found that pyrolysis in the temperature range 220-400°C produced mainly dichlorocarbene. In addition, some trichloromethyl radical was observed and increased in relative importance at increased temperatures. Another identified product of pyrolysis was C6H5HgCl. In general, the same reactive intermediates, CCl2 and CCl3, were found from pyrolysis of Hg(CCl3)2 in the temperature range 250-500°C, along with CCl3HgCl and HgCl2. The identity of CCl2 and CCl2 was demonstrated by measurement of the relative intensities and isotopic splittings of stretching vibrations due to the chlorine isotopes. Isotopic patterns found for CCl2 are: v3 (745.8, 744.0, 741.8 cm-1), v1 (719.5, 717.0, 714.9 cm-1) and for CCl3 are: v3 (897.8, 896.4, 895.2, 893.9 cm-1). Less dilution with the rare gas or warming of the matrix produced a decrease of CCl2 and CCl3 spectral bands and an increase of bands due to C2Cl4, C2Cl6, and other products. These results show the usefulness of matrix isolation in the study of such reactive species as CCl2 produced by pyrolysis in the gas phase. PMID:16591960

Maltsev, A. K.; Mikaelian, R. G.; Nefedov, O. M.; Hauge, R. H.; Margrave, J. L.

1971-01-01

143

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

144

Formation of core-shell-structured Zn2SnO4-carbon microspheres with superior electrochemical properties by one-pot spray pyrolysis  

NASA Astrophysics Data System (ADS)

Core-shell structured Zn2SnO4-carbon microspheres with different carbon contents are prepared by one-pot spray pyrolysis without any further heating process. A Zn2SnO4-carbon composite microsphere is prepared from one droplet containing Zn and Sn salts and polyvinylpyrrolidone (PVP). Melted PVP moves to the outside of the composite microsphere during the drying stage of the droplet. In addition, melting of the phase separated metal salts forms the dense core. Carbonization of the phase separated PVP forms the textured and porous thick carbon shell. The discharge capacities of the core-shell structured Zn2SnO4-carbon microspheres for the 2nd and 120th cycles at a current density of 1 A g-1 are 864 and 770 mA h g-1, respectively. However, the discharge capacities of the bare Zn2SnO4 microspheres prepared by the same process without PVP for the 2nd and 120th cycles are 1106 and 81 mA h g-1, respectively. The stable and reversible discharge capacities of the Zn2SnO4-carbon composite microspheres prepared from the spray solution with 15 g PVP decrease from 894 to 528 mA h g-1 as current density increases from 0.5 to 5 A g-1.Core-shell structured Zn2SnO4-carbon microspheres with different carbon contents are prepared by one-pot spray pyrolysis without any further heating process. A Zn2SnO4-carbon composite microsphere is prepared from one droplet containing Zn and Sn salts and polyvinylpyrrolidone (PVP). Melted PVP moves to the outside of the composite microsphere during the drying stage of the droplet. In addition, melting of the phase separated metal salts forms the dense core. Carbonization of the phase separated PVP forms the textured and porous thick carbon shell. The discharge capacities of the core-shell structured Zn2SnO4-carbon microspheres for the 2nd and 120th cycles at a current density of 1 A g-1 are 864 and 770 mA h g-1, respectively. However, the discharge capacities of the bare Zn2SnO4 microspheres prepared by the same process without PVP for the 2nd and 120th cycles are 1106 and 81 mA h g-1, respectively. The stable and reversible discharge capacities of the Zn2SnO4-carbon composite microspheres prepared from the spray solution with 15 g PVP decrease from 894 to 528 mA h g-1 as current density increases from 0.5 to 5 A g-1. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr05373g

Hong, Young Jun; Kang, Yun Chan

2014-12-01

145

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

146

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

147

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

NASA Astrophysics Data System (ADS)

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 10 at.%). 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 (1 1 1) direction. Due to Sb doping, the crystalline quality and the preferential orientation of SnS films were improved up to 6 at.% of doping concentration. However, when doping concentration was increased above 6 at.%, 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 1.60 eV to 1.15 eV with increase in Sb concentration. The photoluminescence spectra displayed that all the samples have an emission peak centered at 760 nm. At 6 at.% of Sb doping, the film has the lowest resistivity of 2.598 × 10-2 ? cm while the carrier concentration was high.

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

2013-11-01

148

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

149

Magneto-transport characteristics of La1.4Ca1.6Mn2O7 thin film deposited by spray pyrolysis  

NASA Astrophysics Data System (ADS)

Polycrystalline thin films of double layer manganite La1.4Ca1.6Mn2O7 (DLCMO) have been deposited by nebulized spray pyrolysis on single crystal LaAlO3 substrates. These single phase films, having grain size in the range ~70-100 nm, exhibit a ferromagnetic transition (FM) at TC ~ 95 K. The short range FM ordering due to the in-plane spin coherence is shown to occur at a higher temperature around ~125 K. The metal to insulator transition occurs at a lower temperature TP ~ 55 K. The transport mechanism above TC is of Mott's variable range hopping type. Below TC the current-voltage characteristics show non-linear behaviour that becomes stronger with decreasing temperature. At lower temperatures below TCA ~ 50 K, a magnetically frustrated spin glass-like state is known to exist. The DLCMO films exhibit reasonable low field magneto-resistance of ~5% at 0.6 kOe and ~13% at 3 kOe at ~77 K. This has been explained on the basis of complete spin-polarized tunnelling of charge carriers through the insulating (La, Ca)O2 layers between the adjacent MnO2 bilayers.

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

2006-09-01

150

Tin-Incorporation Induced Changes in the Microstructural, Optical, and Electrical Behavior of Tungsten Oxide Nanocrystalline Thin Films Grown Via Spray Pyrolysis  

NASA Astrophysics Data System (ADS)

Undoped and Sn-doped WO3 thin films were grown on cleaned glass substrates by chemical spray pyrolysis, using ammonium tungstate (NH4)2WO4 as the host precursor and tin chloride (SnCl4·5H2O) as the source of dopant. The XRD spectra confirm the monoclinic structure with a sharp narrow peak along (200) direction along with other peaks of low relative intensities for all the samples. On Sn doping, the films exhibit reduced crystallinity relative to the undoped film. The standard deviation for relative peak intensity with dopant concentration shows enhancement in heterogeneous nucleation growth. As evident from SEM images, on Sn doping, appearance of island-like structure (i.e., cluster of primary crystallites at few places) takes place. The transmittance has been found to decrease in all the Sn-doped films. The optical band gap has been calculated for both direct and indirect transitions. On Sn doping, the direct band gap shows a red shift and becomes 2.89 eV at 2 at.% doping. Two distinct peaks, one blue emission at 408 nm and other green emission at 533 nm, have been found in the PL spectra. Electrical conductivity has been found to increase with Sn doping.

Mukherjee, Ramnayan; Prajapati, C. S.; Sahay, P. P.

2014-12-01

151

Physical properties of Zn doped TiO2 thin films with spray pyrolysis technique and its effects in antibacterial activity.  

PubMed

Zinc doped Titanium dioxide (TiO2: Zn) thin films were deposited onto glass substrates by the spray pyrolysis technique with the substrate temperature 450°C. The structural, optical, photoluminescence (PL) properties and morphological studies were investigated for the films deposited with various doping concentration (0, 2, 4, 6 and 8at.%) of zinc. The results of X-ray diffraction (XRD) had shown the presence of anatase peak with a strong orientation along (101) plane at 8at.% of Zn-doped TiO2 film. Scanning electron microscopy (SEM) study showed the uniform distribution of grains with porous nature. Atomic force microscopy (AFM) observations indicated the tetragonal shape at 8at.% of Zn-doped TiO2 with the particle size and decrease in surface roughness. The emission at 398nm was observed at the 8at.% of Zn-doped TiO2 thin film. The carrier concentration and Hall mobility was increased with doping. The antibacterial activity was highly yielded for the Zn-doped TiO2 thin films. PMID:25479105

Arunachalam, A; Dhanapandian, S; Manoharan, C; Sivakumar, G

2015-03-01

152

Effect of substrate temperature on optical, structural and electrical properties of FeSe thin films deposited by spray pyrolysis technique  

NASA Astrophysics Data System (ADS)

The versatile spray pyrolysis technique was employed to prepare thin films of iron selenide on glass substrates at different substrate temperatures. The deposition temperature was varied between 473 and 673 K. The as-deposited films were characterized by X-ray diffraction (XRD), SEM, optical and electrical characterization techniques. The X-ray studies reveal that the films are nanocrystalline with tetragonal structure and exhibit (101) preferred orientation. The SEM and AFM studies indicate that the film surface is homogenous with no cracks or pinholes and well covers the glass substrate. The film thickness was found to vary from 110 to 230 nm with substrate temperature. The optical band gap was found to decrease from 2.92 to 2.68 eV depending on deposition temperature. The resistivity of p-type FeSe film is of the order of 8×104 ? cm and it decreases to 1.5×104 ? cm as substrate temperature is increased from 473 K to 673 K.

Ubale, A. U.; Sakhare, Y. S.

2013-10-01

153

Screen-printed (La,Sr)CrO3 coatings on ferritic stainless steel interconnects for solid oxide fuel cells using nanopowders prepared by means of ultrasonic spray pyrolysis  

NASA Astrophysics Data System (ADS)

In order to protect the cathode from chromium poisoning and improve electrical resistance, a perovskite (La,Sr)CrO3 coating was deposited on the surface of a DIN 50049 ferritic stainless steel by means of the screen-printing method, using a paste composed of an ultra-fine powder prepared via ultrasonic spray pyrolysis. Investigations of the oxidation process of the coated steel in air and the Ar-H2-H2O gas mixture at 1073 K for times up to 820 h showed high compactness of the protective film, good adhesion to the metal substrate, as well as area specific resistance (ASR) at a level acceptable for metallic SOFC interconnect materials. The microstructure, nanostructure, phase composition of the thick film, and in particular the film/substrate interface, were examined via chemical analyses by means of SEM-EDS and TEM-SAD. It was shown that the (La,Sr)CrO3 coating interacts with the steel during long-term thermal oxidation in the afore-mentioned conditions and intermediate, chromia-rich and/or spinel multilayer interfacial zones are formed. Cr-vaporization tests showed that the (La,Sr)CrO3 coating may play the role of barriers that decrease the volatilization rate of chromia species.

Brylewski, Tomasz; Dabek, Jaroslaw; Przybylski, Kazimierz; Morgiel, Jerzy; Rekas, Mieczyslaw

2012-06-01

154

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

155

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

156

Fabrication of antimony doped tin oxide (ATO) films by an inexpensive, simplified spray technique using perfume atomizer  

Microsoft Academic Search

By employing a simplified version of spray technique using perfume atomizer, antimony doped tin oxide (ATO) films were fabricated. The structural, electrical and optical properties of the ATO films prepared by this technique were studied and compared with that of the films grown by the conventional spray pyrolysis method using carrier gas. The preferred orientation of the ATO films was

K. Ravichandran; P. Philominathan

2008-01-01

157

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

158

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

159

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

160

Effect of substrate temperature and precursor ratio on properties of thin ZnS films sprayed by improved method  

NASA Astrophysics Data System (ADS)

Zinc sulphide (ZnS) thin films were prepared by improved spray pyrolysis (ISP) method. The ISP parameters, such as carrier gas flow rate, solution flow rate and substrate temperature, were controlled with an accuracy of ±0.25 lpm, ±1 ml/h and ±1 °C, respectively. The solution was sprayed in a pulsed mode. The substrate temperature was optimized by analyzing substrate temperature dependent properties of thin films. The thin film deposited at a temperature of 450 °C was dense and fairly smooth with satisfactory crystallinity and very small impurity content. The effect of precursor ratio in the solution on structural, compositional and optical properties of thin ZnS films, deposited at a temperature of 450 °C, was studied. A gradual increase in band gap energy from 3.524 eV to 3.634 eV, refractive index from 2.5 to 2.9 and dielectric constant from 6.6 to 8.7 were observed with the variation of solution precursor (Zn:S) ratio from (1:2) to (1:6). The structural and compositional studies support this kind of enhancement in optical properties. The results show that the thin ZnS film prepared by ISP at the substrate temperature of 450 °C from a solution with specific precursor ratio can be used for optoelectronic and photovoltaic applications.

Zaware, Rangnath V.; Wagh, Bhiva G.

2014-09-01

161

Method of making powder for thermal spray application  

SciTech Connect

This patent describes a method for preparing an intimate mixture of powders of nickel-chromium-boron-silicon alloy, molybdenum metal powder, and chromium carbide/nichrome alloy suitable for thermal spray coatings. It comprises milling a starting mixture of the nickel-chromium-boron-silicon alloy, molybdenum powder, and the chromium carbide/nichrome alloy to produce a milled mixture wherein the average particle size is less than about 10 micro-meters in diameter; forming an aqueous slurry of the resulting milled mixture and a binder selected from the group consisting of an ammoniacal molybdate compound and polyvinyl alcohol and agglomerating the milled mixture and the binder to produce the intimate mixture.

Anand, V.; Sampath, S.; Houck, D.L.; Vanderpool, J.E.

1992-06-30

162

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

163

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

164

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

165

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

166

Facile water-based spray pyrolysis of earth-abundant Cu2FeSnS4 thin films as an efficient counter electrode in dye-sensitized solar cells.  

PubMed

A novel approach to produce earth-abundant Cu2FeSnS4 (CFTS) thin film using spray pyrolysis of nontoxic aqueous precursors followed by sulfurization is reported. The CFTS phase formation was confirmed by both Raman spectroscopy and X-ray diffraction techniques. Hall measurements of these films reveal p-type conductivity with good charge carrier density and mobilities appropriate for solar harvesting devices. To the best of our knowledge, this is the first report on the electrical properties of solution-processed Cu2FeSnS4 thin films estimated using Hall measurements. Dye-sensitized solar cells (DSSC) fabricated with CFTS thin film as a photocathode in iodine/iodide electrolyte exhibit good power conversion efficiency, 8.03%, indicating that CFTS would be a promising cheaper alternative to replace Pt as a counter electrode in DSSCs. PMID:25255739

Prabhakar, Rajiv Ramanujam; Huu Loc, Nguyen; Kumar, Mulmudi Hemant; Boix, Pablo P; Juan, Sun; John, Rohit Abraham; Batabyal, Sudip K; Wong, Lydia Helena

2014-10-22

167

Spray method for recovery of heat-injured Salmonella Typhimurium and Listeria monocytogenes.  

PubMed

Selective agar is inadequate for supporting recovery of injured cells. During risk assessment of certain foods, both injured and noninjured cells must be enumerated. In this study, a new method (agar spray method) for recovering sublethally heat-injured microorganisms was developed and used for recovery of heat-injured Salmonella Typhimurium and Listeria monocytogenes. Molten selective agar was applied as an overlay to presolidified nonselective tryptic soy agar (TSA) by spray application. Heat-injured cells (55°C for 10 min in 0.1% peptone water or 55°C for 15 min in sterilized skim milk) were inoculated directly onto solidified TSA. After a 2-h incubation period for cell repair, selective agar was applied to the TSA surface with a sprayer, and the plates were incubated. The recovery rate for heat-injured Salmonella Typhimurium and L. monocytogenes with the spray method was compared with the corresponding rates associated with TSA alone, selective media alone, and the conventional overlay method (selective agar poured on top of resuscitated cells grown on TSA and incubated for 2 h). No significant differences (P > 0.05) were found in pathogen recovery obtained with TSA, the overlay method, and the spray method. However, a lower recovery rate (P < 0.05) was obtained for isolation of injured cells on selective media. Overall, these results indicate that the agar spray method is an acceptable alternative to the conventional overlay method and is a simpler and more convenient approach to recovery and detection of injured cells. PMID:23043840

Back, Kyeong-Hwan; Kim, Sang-Oh; Park, Ki-Hwan; Chung, Myung-Sub; Kang, Dong-Hyun

2012-10-01

168

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

169

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

170

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. PMID:23346340

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

2010-01-01

171

Aerosol Spray Synthesis of Porous Molybdenum Sulfide  

E-print Network

Aerosol Spray Synthesis of Porous Molybdenum Sulfide Powder Submitted by SARA E. SKRABALAK. CLASSIFICATION Form: porous, fine powder Function: hydrodesulfurization catalyst Preparation: aerosol spray ABSTRACT Highly porous, nanostructured MoS2 spheres have been prepared by ultrasonic spray pyrolysis (USP

Suslick, Kenneth S.

172

Real-time method for the identification and quantification of hydrocarbon pyrolysis products: Part II. Application to transient pyrolysis and validation by numerical simulation.  

E-print Network

but also to voluntarily decompose it. Some of the resulting pyrolysis products (among hydrogen, ethylene, methane,... [8]) can hal-00641590,version1-17Nov2011 #12;3/38 present sufficiently low auto-ignition

Paris-Sud XI, Université de

173

Method of high heat flux removal by usage of liquid spray cooling  

NASA Astrophysics Data System (ADS)

High heat flux removal are important issue in many perspective applications such as computer chips, laser diode arrays, or boilers working on supercritical parameters. Electronic microchips constructed nowadays are model example of high heat flux removal, where the cooling system have to maintain the temperature below 358 K and take heat flux up to 300 W/cm2. One of the most efficient methods of microchips cooling turns out to be the spray cooling method. Review of installations has been accomplished for removal at high heat flux with liquid sprays. In the article are shown high flux removal characteristic and dependences, boiling critical parameters, as also the numerical method of spray cooling analysis.

Smakulski, Przemys?aw

2013-09-01

174

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); Arzoumanidis, Gregory G. (Naperville, IL)

1997-01-01

175

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

176

DEVELOPMENT OF PROPOSED STANDARD TEST METHOD FOR SPRAY PAINTING TRANSFER EFFICIENCY. VOLUME 2. VERIFICATION PROGRAM  

EPA Science Inventory

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 used by industry were eval...

177

DEVELOPMENT OF PROPOSED STANDARD TEST METHOD FOR SPRAY PAINTING TRANSFER EFFICIENCY. VOLUME 1. LABORATORY DEVELOPMENT  

EPA Science Inventory

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 used by industry were eval...

178

Estimation of thermal cracking stress during spraying of thermal barrier coatings by laser AE method  

NASA Astrophysics Data System (ADS)

Thermal barrier coatings (TBCs) system is deposited by plasma spray method usually contain a number of cracks. These cracks can be classified into vertical and horizontal cracks and certainly affect the performance of TBCs. A monitoring method to detect the crack generation and propagation during plasma spraying is significantly required. In this study, a laser AE technique which enables in-situ and non-contact monitoring during spring process was developed to study the cracking phenomena in TBC. A new scanning pattern of the plasma torch was successfully applied to introduce only vertical cracks into the top coat. More number of AE events could be obtained by applying an improved noise filtering and multiple-threshold event detection procedures. A temperature history during spraying was also measured and used for thermal stress simulation by FEM analyses. A relationship between cracking and thermal stress in the top coat was established based on the results of AE monitoring and FEM simulation.

Ito, Kaita; Kuriki, Hitoshi; Araki, Hiroshi; Kuroda, Seiji; Enoki, Manabu

2014-02-01

179

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

180

Complementary analytical liquid chromatography methods for the characterization of aqueous phase from pyrolysis of lignocellulosic biomasses.  

PubMed

In this work, two analytical liquid chromatography methods were developed and compared for the characterization of aqueous phases from pyrolysis of lignocellulosic biomasses. NanoLC electron ionization-mass spectrometry (EI-MS) represents a novel and useful tool for both separation and identification of semi/nonvolatile and thermolabile molecules. The use of nanoscale flow rates, the highly reproducibility, and high detailed information on EI spectra are the principal advantages of this technique. On the other hand, comprehensive 2D-LC, providing a two-dimensional separation, increases the overall peak capacity lowering the occurrence of peak coelutions. Despite the use of reversed phase modes in both dimensions, a satisfactory degree of orthogonality was achieved by the employment of a smart design of gradient elution strategies in the second dimension in combination with photodiode array detection (PDA) and atmospheric pressure chemical ionization-mass spectrometry (APCI-MS). Because of the absence of the preliminary extraction procedure, the fingerprint obtained for these samples results is independent of the extraction yield or contamination contrary to the gas chromatography-mass spectrometry (GC-MS) approach where a liquid-liquid extraction of the water phase is necessary. The main classes of identified compounds were phenols, ketones, furans, and alcohols. The synergistic information on the two powerful analytical approaches, e.g., NanoLC EI-MS and LC × LC, in the identification of such complex samples has never been investigated and fully benefit on the one hand from the superior degree of mass spectral information from EI-MS and on the other hand from enhanced LC × LC compound separation. PMID:25327521

Tomasini, Débora; Cacciola, Francesco; Rigano, Francesca; Sciarrone, Danilo; Donato, Paola; Beccaria, Marco; Caramão, Elina B; Dugo, Paola; Mondello, Luigi

2014-11-18

181

Confined-Pyrolysis as an Experimental Method for Hydrothermal Organic Synthesis  

NASA Technical Reports Server (NTRS)

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 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.

1995-01-01

182

On radiative transfer in water spray curtains using the discrete ordinates method  

Microsoft Academic Search

Radiative transfer through water spray curtains has been presently addressed in conditions similar to devices used in fire protection systems. The radiation propagation from the heat source through the medium is simulated using a 2D Discrete Ordinates Method. The curtain is treated as an absorbing and anisotropically scattering medium, made of droplets injected in a mixing of air, water vapor

A. Collin; P. Boulet; D. Lacroix; G. Jeandel

2005-01-01

183

Numerical simulation of spray coalescence in an Eulerian framework: Direct quadrature method of moments and multi-fluid method  

SciTech Connect

The scope of the present study is Eulerian modeling and simulation of polydisperse liquid sprays undergoing droplet coalescence and evaporation. The fundamental mathematical description is the Williams spray equation governing the joint number density function f(v,u;x,t) of droplet volume and velocity. Eulerian multi-fluid models have already been rigorously derived from this equation in Laurent et al. [F. Laurent, M. Massot, P. Villedieu, Eulerian multi-fluid modeling for the numerical simulation of coalescence in polydisperse dense liquid sprays, J. Comput. Phys. 194 (2004) 505-543]. The first key feature of the paper is the application of direct quadrature method of moments (DQMOM) introduced by Marchisio and Fox [D.L. Marchisio, R.O. Fox, Solution of population balance equations using the direct quadrature method of moments, J. Aerosol Sci. 36 (2005) 43-73] to the Williams spray equation. Both the multi-fluid method and DQMOM yield systems of Eulerian conservation equations with complicated interaction terms representing coalescence. In order to focus on the difficulties associated with treating size-dependent coalescence and to avoid numerical uncertainty issues associated with two-way coupling, only one-way coupling between the droplets and a given gas velocity field is considered. In order to validate and compare these approaches, the chosen configuration is a self-similar 2D axisymmetrical decelerating nozzle with sprays having various size distributions, ranging from smooth ones up to Dirac delta functions. The second key feature of the paper is a thorough comparison of the two approaches for various test-cases to a reference solution obtained through a classical stochastic Lagrangian solver. Both Eulerian models prove to describe adequately spray coalescence and yield a very interesting alternative to the Lagrangian solver. The third key point of the study is a detailed description of the limitations associated with each method, thus giving criteria for their use as well as for their respective efficiency.

Fox, R.O. [Department of Chemical and Biological Engineering, 2114 Sweeney Hall, Iowa State University, Ames, IA 50011-2230 (United States); Laurent, F. [Laboratoire d'Energetique Moleculaire et Macroscopique, Combustion, UPR CNRS 288 - Ecole Centrale Paris, Grande Voie des Vignes, 92295 Chatenay-Malabry (France)], E-mail: frederique.laurent@em2c.ecp.fr; Massot, M. [Laboratoire d'Energetique Moleculaire et Macroscopique, Combustion, UPR CNRS 288 - Ecole Centrale Paris, Grande Voie des Vignes, 92295 Chatenay-Malabry (France)

2008-03-01

184

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

185

Synthesis of GdCo{sub 1-x}Cu {sub x}O{sub 3-{delta}} (x = 0, 0.15, 0.30) perovskites by ultrasonic spray pyrolysis  

SciTech Connect

Single-phase GdCo{sub 1-x}Cu {sub x}O{sub 3-{delta}} (x = 0, 0.15, 0.30) perovskites were prepared by ultrasonic-assisted spray pyrolysis, at a reactor temperature of 950 deg. C. The starting aqueous solutions containing stoichiometric amounts of gadolinium, cobalt and copper nitrates, were atomized using an ultrasonic transducer, operated at a frequency of {approx}1.7 MHz. The aerosol droplets were then transported by O{sub 2} inside a preheated tube furnace, where solvent evaporation and chemical reaction take place. X-ray powder diffraction gave as a result pure GdCo{sub 1-x}Cu {sub x}O{sub 3-{delta}} (x = 0, 0.15, 0.30) perovskites; this technique also showed that the replacement of Co by Cu increased the unit cell volume. By field emission scanning electron microscopy and transmission electron microscopy, spherical-hollow particles were observed; a detailed inspection showed that the shells are formed by nanoparticles with an average particle size of 49 nm. The substitution of Co by Cu in members with x = 0.15 and 0.30, was confirmed by energy-dispersive X-ray microanalysis.

Michel, C.R. [Departamento de Fisica, CUCEI, Universidad de Guadalajara, Blvd. M. Garcia Barragan 1421, Guadalajara, Jalisco 44430 (Mexico)]. E-mail: michelucr@yahoo.es; Lopez, E.R. [Departamento de Fisica, CUCEI, Universidad de Guadalajara, Blvd. M. Garcia Barragan 1421, Guadalajara, Jalisco 44430 (Mexico); Zea, H.R. [Center for Micro-Engineered Materials, Farris Engineering Center, University of New Mexico, Albuquerque, NM 87131 (United States)

2006-01-05

186

Effect of solvent volume on the physical properties of aluminium doped nanocrystalline zinc oxide thin films deposited using a simplified spray pyrolysis technique  

NASA Astrophysics Data System (ADS)

Aluminium doped zinc oxide (AZO) thin films were deposited by employing a low cost and simplified spray technique using a perfume atomizer from starting solutions having different volumes (10, 20, … , 50 mL) of solvent. The effect of solvent volume on the structural, electrical, optical, photoluminescence (PL) and surface morphological properties was studied. The electrical resistivity of the AZO films is remarkably influenced by the variation in the solvent volume. The X-ray diffraction profiles clearly showed that all the films have preferential orientation along the (0 0 2) plane irrespective of the solvent volume. The crystallite size was found to be in the nano range of 35-46 nm. The optical transmittance in the visible region is desirably high (>85%). The AFM images show columnar morphology with varying grain size. The PL studies revealed that the AZO film deposited from 50 mL of solvent volume has good quality with lesser defect density.

Jabena Begum, N.; Mohan, R.; Ravichandran, K.

2013-01-01

187

Laser diffraction particle sizing by wet dispersion method for spray-dried infant formula  

Microsoft Academic Search

A laser diffraction particle sizing method involving wet analysis could be adapted effectively to measure the accurate particle size distribution of a spray-dried infant formula. Polar, polar aprotic and non-polar solvents, such as ethanol, methanol, acetone, pentane, heptane and hexane, were tested as dispersants for wet analysis. Non-polar solvents such as pentane, heptane and hexane found to be suitable dispersant

Byung-Man Kwak; Ji Eun Lee; Jang-Hyuk Ahn; Tae-Hong Jeon

2009-01-01

188

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

189

NDE Methods for the External Tank Spray on Foam Insulation  

NASA Technical Reports Server (NTRS)

The foam thermal protection system (TPS) of the space shuttle External Tank (ET) has provided some unique challenges to the nondestructive testing community. Three nondestructive evaluation methods have been developed to identify defects in the foam TPS of the ET. Terahertz imaging and backscatter radiography have been developed to identify voids in thick foam regions while shearography has been developed to identify shallow delaminations, shallow voids and crush damage in the foam. The basic theory of operation along with factors, determined from a series of designed experiments, affecting the results of these methods will be described. Results from both test panels and flight tank inspections will be provided, along with predicted probability of detection estimates to show the range in defect sizes and types that can be readily detected.

Walker, James L.; Johnson, Kenneth L.; Santos, Fernando E.; Ussery, W. Warren

2007-01-01

190

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

191

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

192

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

193

Preparation and characterization of celecoxib dispersions in soluplus(®): comparison of spray drying and conventional methods.  

PubMed

The present study deals with characterization of dispersions of a poorly water-soluble drug, celecoxib (CLX) in polyvinyl caprolactame-polyvinyl acetate-polyethylene glycol graft copolymer (Soluplus(®) (SOL)) prepared by different techniques. Dispersions of CLX in SOL at different ratios (2:1, 1:1, 1:2, 1:4 and 1:6) were prepared by spray drying, conventional solvent evaporation and melting methods. The solid states of samples were characterized using particle size measurements, optical and scanning electron microscopy, XRPD, DSC and FT-IR. The Gordon-Taylor equation was used to predict the Tg of samples and the possibility of interaction between CLX and SOL. The solubility and dissolution rate of all samples were determined. Stability of samples was studied at ambient conditions for a period of 12 months. DSC and XRPD analyses confirmed amorphous state of drug in samples. Surprisingly dispersions of CLX:SOL with the ratio of 2:1 and 1:1 showed slower dissolution rate than CLX while other samples showed higher dissolution rate. At 1:2 ratio the spray dried samples exhibited higher dissolution rate than corresponding samples prepared by other methods. However at higher SOL content (1:4 and 1:6), samples prepared by different methods showed similar dissolution profiles. The stability studies showed that there were no remarkable changes in the dissolution profiles and solid state of the drug after 12 months storage at ambient conditions. It was concluded that SOL was a proper carrier to enhance the dissolution rate of CLX. At high SOL ratios the method of preparation of dispersed samples had no effect on dissolution rate, whilst at low SOL content spray drying was more efficient method. PMID:25561910

Homayouni, Alireza; Sadeghi, Fatemeh; Nokhodchi, Ali; Varshosaz, Jaleh; Afrasiabi Garekani, Hadi

2015-01-01

194

Preparation and Characterization of Celecoxib Dispersions in Soluplus®: Comparison of Spray Drying and Conventional Methods  

PubMed Central

The present study deals with characterization of dispersions of a poorly water-soluble drug, celecoxib (CLX) in polyvinyl caprolactame–polyvinyl acetate–polyethylene glycol graft copolymer (Soluplus® (SOL)) prepared by different techniques. Dispersions of CLX in SOL at different ratios (2:1, 1:1, 1:2, 1:4 and 1:6) were prepared by spray drying, conventional solvent evaporation and melting methods. The solid states of samples were characterized using particle size measurements, optical and scanning electron microscopy, XRPD, DSC and FT-IR. The Gordon-Taylor equation was used to predict the Tg of samples and the possibility of interaction between CLX and SOL. The solubility and dissolution rate of all samples were determined. Stability of samples was studied at ambient conditions for a period of 12 months. DSC and XRPD analyses confirmed amorphous state of drug in samples. Surprisingly dispersions of CLX:SOL with the ratio of 2:1 and 1:1 showed slower dissolution rate than CLX while other samples showed higher dissolution rate. At 1:2 ratio the spray dried samples exhibited higher dissolution rate than corresponding samples prepared by other methods. However at higher SOL content (1:4 and 1:6), samples prepared by different methods showed similar dissolution profiles. The stability studies showed that there were no remarkable changes in the dissolution profiles and solid state of the drug after 12 months storage at ambient conditions. It was concluded that SOL was a proper carrier to enhance the dissolution rate of CLX. At high SOL ratios the method of preparation of dispersed samples had no effect on dissolution rate, whilst at low SOL content spray drying was more efficient method. PMID:25561910

Homayouni, Alireza; Sadeghi, Fatemeh; Nokhodchi, Ali; Varshosaz, Jaleh; Afrasiabi Garekani, Hadi

2015-01-01

195

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. PMID:24143097

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

2013-01-01

196

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

197

Constrained Response Surface Optimisation and Taguchi Methods for Precisely Atomising Spraying Process  

NASA Astrophysics Data System (ADS)

This research presents a development of a design of experiment technique for quality improvement in automotive manufacturing industrial. The quality of interest is the colour shade, one of the key feature and exterior appearance for the vehicles. With low percentage of first time quality, the manufacturer has spent a lot of cost for repaired works as well as the longer production time. To permanently dissolve such problem, the precisely spraying condition should be optimized. Therefore, this work will apply the full factorial design, the multiple regression, the constrained response surface optimization methods or CRSOM, and Taguchi's method to investigate the significant factors and to determine the optimum factor level in order to improve the quality of paint shop. Firstly, 2? full factorial was employed to study the effect of five factors including the paint flow rate at robot setting, the paint levelling agent, the paint pigment, the additive slow solvent, and non volatile solid at spraying of atomizing spraying machine. The response values of colour shade at 15 and 45 degrees were measured using spectrophotometer. Then the regression models of colour shade at both degrees were developed from the significant factors affecting each response. Consequently, both regression models were placed into the form of linear programming to maximize the colour shade subjected to 3 main factors including the pigment, the additive solvent and the flow rate. Finally, Taguchi's method was applied to determine the proper level of key variable factors to achieve the mean value target of colour shade. The factor of non volatile solid was found to be one more additional factor at this stage. Consequently, the proper level of all factors from both experiment design methods were used to set a confirmation experiment. It was found that the colour shades, both visual at 15 and 45 angel of measurement degrees of spectrophotometer, were nearly closed to the target and the defective at quality gate was also reduced from 0.35 WDPV to 0.10 WDPV. This reveals that the objective of this research is met and this procedure can be used as quality improvement guidance for paint shop of automotive vehicle.

Luangpaiboon, P.; Suwankham, Y.; Homrossukon, S.

2010-10-01

198

Integrated gray-level gradient method applied for the extraction of three-dimensional velocity fields of sprays in in-line digital holography.  

PubMed

In this study, an integrated gray-level gradient method is applied to extract the three-dimensional (3D) velocity fields of sprays. This method consists of a conventional edge-sharpness method and a new method, namely, the overall-sharpness method, which is an efficient supplement of the former. And then the synchronization system is designed and assembled to record double-exposure spray holograms in a short time interval. Finally, using the integrated gray-level gradient method and some image processing techniques, the 3D coordinates of droplets are easily obtained, which can be used to evaluate the 3D velocity fields and the size features of spray droplets in different spray injection pressures. It proves that the integrated gray-level gradient method is well applied to measure the characteristics of sprays in in-line digital holography. PMID:22270523

Yang, Yan; Li, Guangyong; Tang, Lili; Huang, Liang

2012-01-10

199

Method and Apparatus for Thermal Spraying of Metal Coatings Using Pulsejet Resonant Pulsed Combustion  

NASA Technical Reports Server (NTRS)

An apparatus and method [or thermal spraying a metal coating on a substrate is accomplished with a modified pulsejet and optionally an ejector to assist in preventing oxidation. Metal such a Aluminum or Magnesium may be used. A pulsejet is first initiated by applying fuel, air. and a spark. Metal is inserted continuously in a high volume of meta1 into a combustion chamber of the pulsejet. The combustion is thereafter. controlled resonantly at high frequency and the metal is heated to a molten state. The metal is then transported from the combustion chamber into a tail pipe of said pulsejet and is expelled therefrom at high velocity and deposited on a target substrate.

Paxson, Daniel E. (Inventor)

2010-01-01

200

Production and analysis of fast pyrolysis oils from proteinaceous biomass  

Technology Transfer Automated Retrieval System (TEKTRAN)

Fast pyrolysis of lignocellulosic biomass is a facile method for producing high yields of liquid fuel intermediates. However, because most fast pyrolysis oils are highly oxygenated, acidic and unstable identification of feedstocks that produce higher quality pyrolysis liquids is desirable. Therefor...

201

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

202

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

203

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

204

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

205

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

206

Miniature spray-painting booth  

NASA Technical Reports Server (NTRS)

Transparent spray booth provides method for quality painting and repair of surfaces in clean room or other specialized environments. Overspray and virtually all contaminating vapor and odor can be eliminated. Touch-up painting is achieved with spray gun.

Fee, K. W.

1970-01-01

207

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

208

Method for minimizing decarburization and other high temperature oxygen reactions in a plasma sprayed material  

DOEpatents

A method is disclosed for spray coating material which employs a plasma gun that has a cathode, an anode, an arc gas inlet, a first powder injection port, and a second powder injection port. A suitable arc gas is introduced through the arc gas inlet, and ionization of the arc gas between the cathode and the anode forms a plasma. The plasma is directed to emenate from an open-ended chamber defined by the boundary of the anode. A coating is deposited upon a base metal part by suspending a binder powder within a carrier gas that is fed into the plasma through the first powder injection port; a material subject to degradation by high temperature oxygen reactions is suspended within a carrier gas that is fed into the plasma through the second injection port. The material fed through the second injection port experiences a cooler portion of the plasma and has a shorter dwell time within the plasma to minimize high temperature oxygen reactions. The material of the first port and the material of the second port intermingle within the plasma to form a uniform coating having constituent percentages related to the powder-feed rates of the materials through the respective ports.

Lenling, William J. (Madison, WI); Henfling, Joseph A. (Bosque Farms, NM); Smith, Mark F. (Albuquerque, NM)

1993-06-08

209

Method for Thermal Spraying of Coatings Using Resonant-Pulsed Combustion  

NASA Technical Reports Server (NTRS)

A method has been devised for high-volume, high-velocity surface deposition of protective metallic coatings on otherwise vulnerable surfaces. Thermal spraying is used whereby the material to be deposited is heated to the melting point by passing through a flame. Rather than the usual method of deposition from the jet formed from the combustion products, this innovation uses non-steady combustion (i.e. high-frequency, periodic, confined bursts), which generates not only higher temperatures and heat transfer rates, but exceedingly high impingement velocities an order of magnitude higher than conventional thermal systems. Higher impingement rates make for better adhesion. The high heat transfer rates developed here allow the deposition material to be introduced, not as an expensive powder with high surface-area-to-volume, but in convenient rod form, which is also easier and simpler to feed into the system. The nonsteady, resonant combustion process is self-aspirating and requires no external actuation or control and no high-pressure supply of fuel or air. The innovation has been demonstrated using a commercially available resonant combustor shown in the figure. Fuel is naturally aspirated from the tank through the lower Tygon tube and into the pulsejet. Air for starting is ported through the upper Tygon tube line. Once operation commences, this air is no longer needed as additional air is naturally aspirated through the inlet. A spark plug on the device is needed for starting, but the process carries on automatically as the operational device is resonant and reignites itself with each 220-Hz pulse.

Paxson, Daniel E.

2008-01-01

210

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

211

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

212

An improved whitecap timescale for sea spray aerosol production flux modeling using the discrete whitecap method  

NASA Astrophysics Data System (ADS)

The discrete whitecap method (DWM) to model the sea spray aerosol (SSA) production flux explicitly requires a whitecap timescale, which up to now has only considered a whitecap decay timescale, ?decay. A reevaluation of the DWM suggests that the whitecap timescale should account for the total whitecap lifetime (?wcap), which consists of both the formation timescale (?form) and the decay timescale (timescale definitions are given in the text). Here values of ?form for 552 oceanic whitecaps measured at the Martha's Vineyard Coastal Observatory on the east coast of the USA are presented, and added to the corresponding values of ?decay to form 552 whitecap timescales. For the majority of whitecaps, ?form makes up about 20-25% of ?wcap, but this can be as large as 70% depending on the value of ?decay. Furthermore, an area-weighted mean whitecap timescale for use in the DWM (?DWM) is defined that encompasses the variable nature of individual whitecap lifetimes within a given time period, and is calculated to be 5.3 s for this entire data set. This value is combined with previously published whitecap coverage parameterizations and estimates of SSA particle production per whitecap area to form a size-resolved SSA production flux parameterization (dF(r80)/dlog10r80). This parameterization yields integrated sea-salt mass fluxes that are largely within the range of uncertainty of recent measurements over the size range 0.029 µm < r80 < 0.580 µm. Physical factors controlling whitecap lifetime such as bubble plume lifetime and surfactant stabilization are discussed in the context of SSA production from whitecaps.

Callaghan, Adrian H.

2013-09-01

213

Kinetics study on conventional and microwave pyrolysis of moso bamboo.  

PubMed

A comparative study on the pyrolysis kinetics of moso bamboo has been conducted in a conventional thermogravimetric analyzer and a microwave thermogravimetric analyzer respectively. The effect of heating rate on the pyrolysis process was also discussed. The results showed that both the maximum and average reaction rates increased with the heating rate increasing. The values of activation energy increased from 58.30 to 84.22 kJ/mol with the heating rate decreasing from 135 to 60 °C/min during conventional pyrolysis. The value of activation energy was 24.5 kJ/mol for microwave pyrolysis, much lower than that for conventional pyrolysis at a similar heating rate of 160 °C/min. The pyrolysis of moso bamboo exhibited a kinetic compensation effect. The low activation energy obtained under microwave irradiation suggests that microwaves heating would be a promising method for biomass pyrolysis. PMID:25194260

Dong, Qing; Xiong, Yuanquan

2014-11-01

214

High-temperature digital image correlation method for full-field deformation measurement captured with filters at 2600°C using spraying to form speckle patterns  

NASA Astrophysics Data System (ADS)

A method is presented for obtaining good images of a sprayed speckle pattern on specimen surfaces at high temperatures, suitable for strain measurement, by digital image correlation (DIC) using plasma spray for speckle preparation in which a bandpass filter, neutral density filters, and a linear polarizing filter are used to reduce intensity and noise in images. This is accomplished by speckle preparation through the use of plasma spray and suppression of black-body radiation through the use of filters. By using plasma spray for speckle preparation and the filters for image acquisition, the method was demonstrated to be capable of providing accurate DIC measurements up to 2600°C. The full-field stretching deformation of the specimen was determined using the DIC technique. Experimental results indicate that the proposed high-temperature DIC method is easy to implement and can be applied to practical, full-field, high-temperature deformation measurements with high accuracy.

Guo, Xiang; Liang, Jin; Tang, Zhengzong; Cao, Binggang; Yu, Miao

2014-06-01

215

Manufacturing methods and technology measure arc plasma for sprayed phase shifter elements  

Microsoft Academic Search

Nonmagnetic Li-Ti ferrite dielectrics have been processed, fired and ground to final dimensions in preparation for arc plasma spraying (APS). Thermal expansion data are given on a series of compositions with variations in alumina content. The ferrite powder to be used for APS coating has been examined by SEM and X-ray fluorescent analysis. We report data on microwave and other

H. J. Vanhook; L. Lesensky; H. Miller

1975-01-01

216

Manufacturing methods and technology measure for arc plasma sprayed phase shifter elements  

Microsoft Academic Search

Physical property data are given on a series of nonmagnetic Li-Ti ferrite dielectrics which have been used in arc plasma spraying of phase shifter samples. Thermal expansion data are given on a new series of compositions with variations in Li-Ti and Al content. A new fully reacted ferrite powder has been characterized in terms of particle size and magnetic properties.

H. J. Vanhook; D. Masse; J. Saunders

1976-01-01

217

High order moment method for polydisperse evaporating sprays with mesh movement: application to internal combustion engines  

E-print Network

to internal combustion engines D. Kaha,3 , O. Emreb,c,d,2 , Q. H. Trand , S. de Chaisemartind, , S. Jayd , F meshes. Extending the approach to internal combustion engine and fuel injection requires solving two simulations with spray in internal combustion engines have become a critical target in the automotive industry

Paris-Sud XI, Université de

218

APPLICATION OF A SPRAY DEPOSITION METHOD FOR REVERSED PHASE LIQUID CHROMATOGRAPHY-MASS SPECTROMETRY  

EPA Science Inventory

Four coal gasification wastewater samples were analyzed for nonvolatile and polar organics by liquid chromatography-mass spectrometry (LC/MS). Samples were separated on a reverse phase liquid chromatographic column using an aqueous solvent as the eluant. A special spray depositio...

219

An improved method to study the impact of pesticide sprays on small song birds  

Microsoft Academic Search

Four test groups of small songbirds (Zebra Finch, Poephila guttata) were sprayed in a chamber with varying concentrations of fenitrothion. Exposure levels were assessed by monitoring air concentrations, deposits of the active ingredient (AI) on glass plates and droplets\\/cm on Kromekote® cards. All indices of exposure were linearly correlated and the mean AI deposit on glass plates for the four

Pierre Mineau; Kanth M. S. Sundaram; Alam Sundaram; Cecilia Feng; Donald G. Busby; Peter A. Pearce

1990-01-01

220

Carbon nanoscrolls by pyrolysis of a polymer  

NASA Astrophysics Data System (ADS)

3D network of carbon nanoscrolls was synthesized starting from pyrolysis of poly(acrylic acid-co-maleic acid) sodium salt. It is a catalyst-free process where pyrolysis of polymer leads to formation of carbon form and sodium carbonate. Upon water soaking of pyrolysis product, the carbon form undergoes self-assembly to form carbon nanoscrolls. The interlayer distance between the walls of carbon nanoscroll was found to be 0.34 nm and the carbon nanoscrolls exhibited a surface area of 188 m2/g as measured by the BET method.

Yadav, Prasad; Warule, Sambhaji; Jog, Jyoti; Ogale, Satishchandra

2012-12-01

221

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

222

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

223

Zone heating for fluidized bed silane pyrolysis  

NASA Technical Reports Server (NTRS)

An improved heated fluidized bed reactor and method for the production of high purity polycrystalline silicon by silane pyrolysis wherein silicon seed particles are heated in an upper heating zone of the reactor and admixed with particles in a lower reaction zone, in which zone a silane-containing gas stream, having passed through a lower cooled gas distribution zone not conducive to silane pyrolysis, contacts the heated seed particles whereon the silane is heterogeneously reduced to silicon.

Iya, Sridhar K. (Inventor)

1987-01-01

224

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

225

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

226

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 different surface preparation conditions before applying the coating, e.g., grit-blasted surface, wire-brush cleaned surface, and a dirty surface. A quad-frequency eddy current probe was used to manually scan over the coating surface to evaluate the bonding quality. Experimental results show that the three surface preparation conditions can be successfully differentiated by looking into the impedance difference observed from the eddy current probe. The measurement is fairly robust and consistent. More specimens are also prepared with variations of process parameters, such as spray angle, stand-off distance, and application of corrosion protective sealant, etc. They are blindly tested to evaluate the reliability of the eddy current system. Quantitative relations between the coating bond strength and the eddy current response are also established with the support of destructive testing. This non-contact, non-destructive, 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; X. Zhao; R. Bayles

2006-05-26

227

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

228

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

229

Potential method for gas production: High temperature co-pyrolysis of lignite and sewage sludge with vacuum reactor and long contact time.  

PubMed

Lignite and sewage sludge were co-pyrolyzed in a vacuum reactor with high temperature (900°C) and long contact time (more than 2h). Beneficial synergetic effect on gas yield was clearly observed. Gas yield of blend fuel was evidently higher than that of both parent fuels. The gas volume yield, gas lower heating value (LHV), fixed carbon conversion and H2/CO ratio were 1.42Nm(3)/kg(blend fuel), 10.57MJ/Nm(3), 96.64% and 0.88% respectively, which indicated this new method a feasible one for gas production. It was possible that sewage sludge acted as gasification agents (CO2 and H2O) and catalyst (alkali and alkaline earth metals) provider during co-pyrolysis, promoting CO2-char and H2O-char gasification which, as a result, invited the improvement of gas volume yield, gas lower heating value and fixed carbon conversion. PMID:25542402

Yang, Xiao; Yuan, Chengyong; Xu, Jiao; Zhang, Weijiang

2015-03-01

230

Study on initial permeability of Ni-Zn ferrite films prepared by the spin spray method  

NASA Astrophysics Data System (ADS)

Initial permeability of Ni-Zn ferrite films prepared by spin spray chemical plating is investigated. They exhibit a semi-hard magnetization process but have relatively high permeability with explicit dual peak resonance loss in the GHz frequency range. In this study, it turned out that the loss is determined mainly by the two magnetic parameters, namely, the crystalline anisotropy and a uniaxial anisotropy induced by Co addition. Measurement of permeability in an external DC field clarified that the semi-hard wall coercivity fixes the spin direction of residual magnetization state and, consequently, gives rise to uniaxial permeability with dependence of its direction on the previously applied DC field.

Shimada, Yutaka; Matsushita, Nobuhiro; Abe, Masanori; Kondo, Koichi; Chiba, T.; Yoshida, Shigeyoshi

2004-07-01

231

Systematic interconnected web-like architecture growth of sprayed TiO2 films.  

PubMed

Systematic improvement in interconnected web-like architecture with thickness of TiO2 films synthesized by spray pyrolysis method is reported and characterized for the structural, optical, surface morphological, and wettability properties. Deposited TiO2 films were crystalline with [120] direction orientation, uniform and adherent to the glass substrate. Interestingly, with increase in film thickness, fuzzy and blurred web-like architecture becomes more clear and sharp with well-defined boundaries. The band gap energy was decreased with increase in film thickness. Change in surface architecture resulted into smaller surface wettability in thick film compared to thin one. PMID:17270449

More, A M; Gunjkar, J L; Lokhande, C D; Mane, R S; Han, Sung-Hwan

2007-01-01

232

Catalytic pyrolysis-GC/MS of lignin from several sources  

Technology Transfer Automated Retrieval System (TEKTRAN)

Lignin from four different sources extracted by various methods were pyrolyzed at 650 degree C using analytical pyrolysis methods, py-GC/MS. Pyrolysis was carried out in the absence and presence of two heterogeneous catalysts , an acidic zeolite (HZSM-5) catalyst and a mixed metal oxide catalyst (Co...

233

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

234

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

235

Supersonic-Spray Cleaner  

NASA Technical Reports Server (NTRS)

Spraying system for cleaning mechanical components uses less liquid and operates at pressures significantly lower. Liquid currently used is water. Designed to replace chlorofluorocarbon (CFC) solvent-based cleaning and cleanliness verification methods. Consists of spray head containing supersonic converging/diverging nozzles, source of gas at regulated pressure, pressurized liquid tank, and various hoses, fittings, valves, and gauges. Parameters of nozzles set so any of large variety of liquids and gases combined in desired ratio and rate of flow. Size and number of nozzles varied so system built in configurations ranging from small hand-held spray heads to large multinozzle cleaners. Also used to verify part adequately cleaned. Runoff liquid from spray directed at part collected. Liquid analyzed for presence of contaminants, and part recleaned if necessary.

Caimi, Raoul E. B.; Lin, Feng-Nan; Thaxton, Eric A.

1995-01-01

236

Pyrolysis of cellulose and lignin  

NASA Astrophysics Data System (ADS)

X-ray and UV-induced photoelectron spectroscopy (XPS and UPS) and scanning electron microscopy (SEM) have been performed to characterise the pyrolysis of cellulose and lignin and their interaction with methanol. Clean highly oriented pyrolitic graphite (HOPG) was also analysed as a reference material. Asymmetric C1s core level fits and valence band XPS of the samples indicate a graphitic-like structure after the pyrolysis at 1200 °C. Due to the low polar contents in pyrolysed cellulose and lignin, an interaction with methanol under high vacuum conditions could not be identified. From a technical viewpoint a temperature of 1200 °C is attainable without high costs. Therefore, the pyrolysis of wood-based polymers containing high amounts of cellulose and lignin are potential low-cost materials for various applications. If it is possible to generate graphite in complex structures made of wood-based polymers, a cheap and energy-efficient method will become available for producing bipolar plates for fuel cells. Technical problems like form instability and foaming are discussed as well as further development and possible modifications of the ground material to achieve optimal compositions.

Haensel, T.; Comouth, A.; Lorenz, P.; Ahmed, S. I.-U.; Krischok, S.; Zydziak, N.; Kauffmann, A.; Schaefer, J. A.

2009-06-01

237

Qualitative characteristics of the fuel gas obtained as a result of the thermochemical processing of plant biomass by the pyrolysis method  

Microsoft Academic Search

Results of experimental investigations on determination of the output, composition, and combustion heat of the fuel gas obtained\\u000a as a result of the pyrolysis of willow and alder sawdust, wood-waste pellets, peat, neutralized hydrolytic lignin, and plant-growing\\u000a wastes (straw and flax boon) and the mechanisms of its formation under different pyrolysis conditions are presented.

P. L. Falyushin; G. I. Zhuravskii; R. F. Bratishko; V. N. Kozhurin; E. V. Anufrieva

2009-01-01

238

Spray Calendar.  

E-print Network

rvr-lub8-30m TEXAS AGRICULTURAL EXPERIMENT STATIONS. BULLETIN NO. 113. AUGUST, 1908. SPRAY CALENDAR C. E. SANBORN, ENTOMOLOGIST. POSTOFFICE. COLLEGE STATION, BRAZOS COUB AUSTIN: VON BOECKMANN-JONES COMP,4NY, PRIl 1908. TEXAS AGRICULTURAL...-half gallon of nrarm rater; pour this into a vessel containing the bran and arsenic - *In a former spray calendar (Circular No. 10) issued by this department is designated a "Bordeaux Mixture" for stone fruits. To this the following phrase should be added...

Sanborn, C. E. (Charles Emerson)

1908-01-01

239

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

240

Method of making supercritical fluid molecular spray films, powder and fibers  

DOEpatents

Solid films are deposited, or fine powders formed, by dissolving a solid material into a supercritical fluid solution at an elevated pressure and then rapidly expanding the solution through a heated nozzle having a short orifice into a region of relatively low pressure. This produces a molecular spray which is directed against a substrate to deposit a solid thin film thereon, or discharged into a collection chamber to collect a fine powder. In another embodiment, the temperature of the solution and nozzle is elevated above the melting point of the solute, which is preferably a polymer, and the solution is maintained at a pressure such that, during expansion, the solute precipitates out of solution within the nozzle in a liquid state. Alternatively, a secondary solvent mutually soluble with the solute and primary solvent and having a higher critical temperature than that of primary solvent is used in a low concentration (<20%) to maintain the solute in a transient liquid state. The solute is discharged in the form of long, thin fibers. The fibers are collected at sufficient distance from the orifice to allow them to solidify in the low pressure/temperature region.

Smith, Richard D. (Richland, WA)

1988-01-01

241

Identification and characterization of vinylpyrrolidone-vinylimidazolium chloride copolymers in cosmetic products by pyrolysis-gas chromatography-mass spectrometry method.  

PubMed

Synopsis Commercially available copolymers of 1-vinyl-2-pyrrolidone and 1-vinyl-3-methylimidazolium chloride, known as 'Luviquat' types in the cosmetic industry, were analysed for their composition using a combination of pyrolysis-gas chromatography-mass spectrometry method. This is a report on the determined pyrolytic products and the fast identification of the analysed polymers both in raw materials and cosmetic products. Calibration with defined material ensures the determination of monomer ratios with good reproducibility. Résumé Les copolymères de chlorure de 1-vinyle-2-pyrolidone et de 1-vinyle-3-methylimidazolium disponibles dans le commerce, connus dans l'industrie cosmétique sous la dénomination de copolymères de vinyle, ont été analysés à laide d'une méthode combinant la pyrolyse, la spectrométrie de mass et la chromatographie en phase gazeuse. Cet article constitue un rapport sur les produits déterminés par pyrolyse et sur la rapidité d'identification des polymères analysés à la fois dans des matières premières et dans des produits cosmétiques. Le calibrage avec un matériel défini assure une bonne détermination des taux de monomères dotés d'une reproductibilité. PMID:19272122

Gmahl, E; Ruess, W

1993-04-01

242

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

243

Thermal spray processing  

NASA Technical Reports Server (NTRS)

Thermal spray processing has been used for a number of years to cost-effecticely apply TBC's for a wide range of heat engine applications. In particular, bond coats are applied by plasma spray and HVOF techniques and partially-stabilized zirconia top coats are applied by plasma spray methods. Thermal spray involves melting and rapid transport of the molten particles to the substrate, where high-rate solidification and coating build-up occur. It is the very nature of this melt processing that leads to the unique layered microstructure, as well as the apparent imperfections, so readily identified with thermal spray. Modeling the process, process-induced residual stresses, and thermal conductivity will be discussed in light of a new understanding of porosity and its anisotropy. Microcracking can be understood using new approaches, allowing a fuller view of the processing-performance connection. Detailed electron microscopic, novel neutron diffraction and fracture analysis of the deposits can lead to a better understanding of how overall microstructure can be controlled to influence critical properties of the deposited TBC system.

Herman, H.; Berndt, C. C.

1995-01-01

244

Determining residence time and hydrocarbon partial pressure in pyrolysis furnaces  

SciTech Connect

A method of calculating residence time and hydrocarbon partial pressure which is applicable to both pilot and commercial pyrolysis coils has been developed. This method allows direct comparison of pilot unit and plant sampler data. Experimental data obtained with ARCO's pilot unit and olefins plant sampling device demonstrate good agreement between the two units. This method has also been extended to ARCO's millisecond pyrolysis furnaces, with similar results.

Cozzone, G.E.; Vavra, F.J.

1987-01-01

245

Combustion properties of slow pyrolysis bio-oil produced from indigenous Australian species  

Microsoft Academic Search

Bio-oil derived via slow pyrolysis process of two indigenous Australian tree species, red gum (Eucalyptus camaldulensis) from the basin of Murray, Victoria, and blue gum (Eucalyptus globulus) wood from the region of Mount Gambier, South Australia was blended with ethanol and burned in a circular jet spray at atmospheric pressure. Bio-oil flames were shorter, wider and brighter than diesel fuel

V. Stamatov; D. Honnery; J. Soria

2006-01-01

246

Pyrolysis of Table Sugar  

PubMed Central

Table sugars were pyrolyzed at different temperatures (300, 400, and 500°C) in a fixed-bed reactor. The effect of pyrolysis temperature on yields of liquid, solid, and gaseous products was investigated. As expected the yield of liquid products gradually increased and the yield of solid products gradually decreased when the pyrolysis temperature was raised. The yield of liquid products was greatest (52?wt%) at 500°C. The composition of bio-oils extracted with diethyl ether was identified by means of gas chromatography mass spectrometry (GC-MS), nuclear magnetic resonance (1H-NMR), and Fourier transform infrared spectroscopy (FTIR). The following compounds were observed in bio-oils produced from the pyrolysis of table sugar at 500°C: 1,4:3,6-dianhydro-?-d-glucopyranose, 5-(hydroxymethyl) furfural, 5-acetoxymethyl-2-furaldehyde, and cyclotetradecane liquid product. The relative concentration of 5-(hydroxymethyl) furfural was the highest in bio-oils obtained from pyrolysis of table sugars at 500°C. PMID:24223500

Karagöz, Selhan

2013-01-01

247

[Structural identification of carboxylic esters by pyrolysis gas chromatography].  

PubMed

A pyrolysis gas chromatographic method has been investigated for structural identification of carboxylic esters. The method can be applied to identify not only pure components, but also those separated by thin layer chromatography and scraped from the TLC plate without removing the adsorbent. The samples were pyrolyzed in tube furnace pyrolyzer at 500 degrees C (conventional pyrolysis) or were pyrolyzed at 550 degrees C after mixing with soda-lime powder (pyrolysis with soda-lime). Some esters such as iso-octyl palmitate, glycerol monostearate and diethyl phthalate were pyrolyzed. The pyrolysis products were identified by comparing with the known. The parent alcohols of monohydric and polyhydric alcohol esters can be determined respectively according to alcohols, alkenes produced on pyrolysis and dehydrated products of polyhydric alcohol at high temperature. The parent acids of monocarboxylic esters can be determined according to carboxylic acid produced on conventional pyrolysis or corresponding alkane formed from decarboxylation of parent acids on pyrolysis with soda-lime. For esters formed from dicarboxylic acids that can be dehydrated to produce five-, six-membered cyclic ketones or can be dehydrated and decarboxylated simultaneously to produce five-, six-membered cyclic acid anhydrides, parent acids can be determined according to corresponding cyclic ketones or cyclic acid anhydrides. This method is useful for identification of common carboxylic esters. When the compound or the component of the mixture was confirmed to contain ester-group by infra-red spectroscopy, PGC or TLC-PGC can be employed to make further identification. PMID:15739430

Liu, E; Chen, W

1997-01-01

248

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

249

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

250

Rapid method for hydrocarbon-type analysis of heavy oils and synthetic fuels by pyrolysis thin layer chromatography  

Microsoft Academic Search

This work describes a rapid method for hydrocargon-type analysis applying thin layer chromatography (TLC) to the pentane-soluble fraction *malthenes) of the petroleum and synthetic fuels boiling above 200°C. The principal component types encountered in this paper are saturates (SA), aromatics (AR), (mono and di together) polynuclear aromatics (PNA) and polar material (PO). The method uses a Iatroscan TLC pyrolyzer which

M. A. Poirier; A. E. George

1982-01-01

251

A method to determine the course of heating value and heat production rate of volatiles during the pyrolysis of a solid fuel particle  

Microsoft Academic Search

The heating value of volatiles released from a solid fuel particle during pyrolysis is determined as a function of time. The experimental setup consists of a thermogravimetric analyser (TGA) and a flow-calorimeter (FC). One single fuel particle is quickly inserted into the TGA which is continuously purged with N2 and operated at a constant temperature of 825°C. The evolved volatiles

G Steiner; J Rath; M. G Wolfinger; G Staudinger

2003-01-01

252

Rapid method for hydrocarbon-type analysis of heavy oils and synthetic fuels by pyrolysis thin layer chromatography  

SciTech Connect

This work describes a rapid method for hydrocargon-type analysis applying thin layer chromatography (TLC) to the pentane-soluble fraction *malthenes) of the petroleum and synthetic fuels boiling above 200/sup 0/C. The principal component types encountered in this paper are saturates (SA), aromatics (AR), (mono and di together) polynuclear aromatics (PNA) and polar material (PO). The method uses a Iatroscan TLC pyrolyzer which combines the resolution capabilities of TLC with the possibility of quantification by using a flame-ionization detector (FID). Comparison of the results with those obtained by the API-60 procedure is presented.

Poirier, M.A.; George, A.E.

1982-09-01

253

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

254

A rapid method for hydrocarbon-type analysis of heavy oils and synthetic fuels by pyrolysis thin layer chromatography  

SciTech Connect

Hydrocarbon-type fractions (saturates, aromatics, polynuclear aromatics, and polar compounds) from heavy crude oils and synthetic fuels were separated by thin layer chromatography (TLC) on chromarods, using an Iatroscan TH-10 analyzer. The best results were obtained on a silica gel chromarod when nhexane, 10 percent benzene in n-hexane, and 5 percent ethyl acetate in benzene were used as developing solvent. A complete analysis of six samples takes 60 min and requires only 60 mg of sample. Separation was applied to pure hydrocarbon mixtures as well as hydrocarbon-type concentrates isolated from Athabasca bitumen by liquid chromatography. The method is applicable to middle distillates, b.p. 200 to 350/sup 0/C, as well as to deasphaltened fractions (malthenes) boiling higher than 350/sup 0/C. Seven samples of malthenes (penthane-solubles) were analyzed by this method. Repeatability of the results was compared with that of the USBM-API procedure.

Poirier, M.A.; George, A.E.

1983-01-01

255

Plasma spraying method for forming diamond and diamond-like coatings  

DOEpatents

A method and composition is disclosed for the deposition of a thick layer of diamond or diamond-like material. The method includes high temperature processing wherein a selected composition 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. The softened or molten composition crystallizes on the substrate to form a thick deposition layer comprising at least a diamond or diamond-like material. The selected composition includes at least glassy carbon as a primary constituent and may include at least one secondary constituent. Preferably, the secondary constituents are selected from the group consisting of at least diamond powder, boron carbide (B{sub 4}C) powder and mixtures thereof. 9 figs.

Holcombe, C.E.; Seals, R.D.; Price, R.E.

1997-06-03

256

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

257

Manufacturing methods and technology measure for arc-plasma sprayed phase-shifter elements  

Microsoft Academic Search

The Phased-array radar antenna is now well established as a means of achieving agile search and multi-target tracking in the current and projected military government. Each new system with its phased-array antenna has many thousands of radiating elements. Since each element contains a ferrite phase shifter, it is appropriate to develop manufacturing methods and processes that will minimize the cost

J. J. Green; H. J. Vanhook; R. J. Maher; D. Masse

1977-01-01

258

Characteristics of hydroxyapatite coated titanium porous coatings on Ti-6Al-4V substrates by plasma sprayed method.  

PubMed

A porous metal coating applied to solid substrate implants has been shown, in vivo, to anchor implants by bone ingrowth. Calcium phosphate ceramics, in particular hydroxyapatite [Ca(10)(PO(4))(6)(OH)(2), HA], are bioactive ceramics, which are known to be biocompatible and osteoconductive, and these ceramics deposited on to porous-coated devices may enhance bone ingrowth and implant fixation. In this study, bi-feedstock of the titanium powder and composite (Na(2)CO(3)/HA) powder were simultaneously deposited on a Ti-6Al-4V substrate by a plasma sprayed method. At high temperature of plasma torch, the solid state of Na(2)CO(3) would decompose to release CO(2) gas and then eject the molten Ti powder to induce the interconnected pores in the coatings. After cleaning and soaking in deionized water, the residual Na(2)CO(3) in the coating would dissolve to form the open pores, and the HA would exist at the surface of pores in the inner coatings. By varying the particle size of the composite powder, the porosity of porous coating could be varied from 25.0 to 34.0%, and the average pore size of the porous coating could be varied to range between 158.5 and 202.0 microm. Using a standard adhesive test (ASTM C-633), the bonding strength of the coating is between 27.3 and 38.2 MPa. By SEM, the HA was observed at the surface of inner pore in the porous coating. These results suggest that the method exhibits the potential to manufacture the bioactive ceramics on to porous-coated specimen to achieve bone ingrowth fixation for biomedical applications. PMID:17245748

Yang, C Y; Chen, C R; Chang, E; Lee, T M

2007-08-01

259

Agricultural Spraying  

NASA Technical Reports Server (NTRS)

AGDISP, a computer code written for Langley by Continuum Dynamics, Inc., aids crop dusting airplanes in targeting pesticides. The code is commercially available and can be run on a personal computer by an inexperienced operator. Called SWA+H, it is used by the Forest Service, FAA, DuPont, etc. DuPont uses the code to "test" equipment on the computer using a laser system to measure particle characteristics of various spray compounds.

1986-01-01

260

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

261

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

262

Effect of whey protein isolate and ?-cyclodextrin wall systems on stability of microencapsulated vanillin by spray-freeze drying method.  

PubMed

Vanillin flavour is highly volatile in nature and due to that application in food incorporation is limited; hence microencapsulation of vanillin is an ideal technique to increase its stability and functionality. In this study, vanillin was microencapsulated for the first time by non-thermal spray-freeze-drying (SFD) technique and its stability was compared with other conventional techniques such as spray drying (SD) and freeze-drying (FD). Different wall materials like ?-cyclodextrin (?-cyd), whey protein isolate (WPI) and combinations of these wall materials (?-cyd+WPI) were used to encapsulate vanillin. SFD microencapsulated vanillin with WPI showed spherical shape with numerous fine pores on the surface, which in turn exhibited good rehydration ability. On the other hand, SD powder depicted spherical shape without pores and FD encapsulated powder yielded larger particle sizes with flaky structure. FTIR analysis confirmed that there was no interaction between vanillin and wall materials. Moreover, spray-freeze-dried vanillin+WPI sample exhibited better thermal stability than spray dried and freeze-dried microencapsulated samples. PMID:25529646

Hundre, Swetank Y; Karthik, P; Anandharamakrishnan, C

2015-05-01

263

Measurement of visibility through spray  

E-print Network

of visual impairment from simulated levels of splash and spray on target vehicle identification distances. Five levels of hand held spray simulation frames were used to compare image digitization methods with visual performance (Snellen acuity... or contrast sensitivity) assessment to predict a drivers ability to identify an oncoming target vehicle. The image digitization process was found to be highly correlated with actual target vehicle identification distances. Additionally, very high...

Wright, Bruce Alan

2012-06-07

264

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

265

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 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. 4 figs.

Kuo, L.J.H.; Vora, S.D.

1995-02-21

266

In situ fuel concentration measurement near a spark plug in a spray-guided direct-injection spark-ignition engine using infrared absorption method  

NASA Astrophysics Data System (ADS)

Vaporized fuel concentration in a spray-guided direct-injection spark-ignition (SG-DISI) engine was measured using an optical sensor installed in a spark plug. A laser infrared absorption method was applied to quantify the instantaneous gasoline concentration near the spark plug. This paper discusses the feasibility of obtaining in situ air-fuel ratio measurements with this sensor installed inside an SG-DISI engine cylinder. First, the effects of the spray plume from a multi-hole injector on the vaporized fuel concentration measurements near the spark-plug sensor were examined using a visible laser. We determined the best position for the sensor in the engine, which was critical due to the spray and vapor plume formation. Then, a 3.392-?m He-Ne laser that coincided with the absorption line of the hydrocarbons was used as a light source to examine the stratified mixture found during ultra-lean engine operation. A combustible mixture existed around the spark plug during the injection period when a preset air-fuel ratio of 45.0 was used with different fuel injection timings and net mean effect pressure conditions. The effects of the orientation of the spark plug on the measured results and ignitability of the SG-DISI engine were examined. Orienting the spark plug vertically to one of the spray plumes provided more accurate results and better engine reliability. The study demonstrated that it was possible to qualify the air-fuel ratio near the spark plug during the injection period using the developed spark-plug sensor in an SG-DISI engine.

Kawahara, Nobuyuki; Tomita, Eiji; Kadowaki, Takuya; Honda, Tetsuya; Katashiba, Hideaki

2010-10-01

267

TG-DSC-FTIR Analysis of Cyanobacteria Pyrolysis  

NASA Astrophysics Data System (ADS)

Pyrolysis of cyanobacteria from Dianchi lake was investigated by TG-DSC-FTIR analysis at different heating rates (10, 20, 40°C/min). The results indicated that the pyrolysis of cyanobacteria can be divided into four stages: evaporation, depolymerization, devolatilization and carbonization. Meanwhile, the initial weight-loss temperature, weight-loss extreme position, endothermic and exothermic peaks were moved to higher temperature with the increaseing of the heating rate. The kinetic analysis was made with Popescu method. It indicated that the best kinetic model for the pyrolysis of cyanobacteria was the cylindrical symmetry of the phase boundary reaction model. The main pyrolysis gases checked with real-time online FTIR were HCN, NH3, CO, CO2, water vapor and hydrocarbons.

Supeng, Luo; Guirong, Bao; Hua, Wang; Fashe, Li; Yizhe, Li

268

Corrosivity Of Pyrolysis Oils  

SciTech Connect

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 carbon steel and other alloys with relatively low chromium content. Stress corrosion cracking samples of carbon steel and several low alloy steels developed through-wall cracks after a few hundred hours of exposure at 50 C. Thermochemical processing of biomass can produce solid, liquid and/or gaseous products depending on the temperature and exposure time used for processing. The liquid product, known as pyrolysis oil or bio-oil, as produced contains a significant amount of oxygen, primarily as components of water, carboxylic acids, phenols, ketones and aldehydes. As a result of these constituents, these oils are generally quite acidic with a Total Acid Number (TAN) that can be around 100. Because of this acidity, bio-oil is reported to be corrosive to many common structural materials. Despite this corrosive nature, these oils have the potential to replace some imported petroleum. If the more acidic components can be removed from this bio-oil, it is expected that the oil could be blended with crude oil and then processed in existing petroleum refineries. The refinery products could be transported using customary routes - pipelines, barges, tanker trucks and rail cars - without a need for modification of existing hardware or construction of new infrastructure components - a feature not shared by ethanol.

Keiser, James R [ORNL] [ORNL; Bestor, Michael A [ORNL] [ORNL; Lewis Sr, Samuel Arthur [ORNL] [ORNL; Storey, John Morse [ORNL] [ORNL

2011-01-01

269

Optimal spray characteristics in water spray cooling  

Microsoft Academic Search

The dependence of the efficiency of liquid usage (?) at CHF on spray parameters was experimentally investigated for subcooled water spray cooling. A spray can be characterized by three independent parameters (droplet Sauter-mean diameter, d32, droplet velocity, V, and droplet flux, N). In this study, each of these parameters was varied with the other two kept constant by using a

Ruey-Hung Chen; Louis C. Chow; Jose E. Navedo

2004-01-01

270

Kinetics of scrap tyre pyrolysis under vacuum conditions  

SciTech Connect

Scrap tyre pyrolysis under vacuum is attractive because it allows easier product condensation and control of composition (gas, liquid and solid). With the aim of determining the effect of vacuum on the pyrolysis kinetics, a study has been carried out in thermobalance. Two data analysis methods have been used in the kinetic study: (i) the treatment of experimental data of weight loss and (ii) the deconvolution of DTG (differential thermogravimetry) curve. The former allows for distinguishing the pyrolysis of the three main components (volatile components, natural rubber and styrene-butadiene rubber) according to three successive steps. The latter method identifies the kinetics for the pyrolysis of individual components by means of DTG curve deconvolution. The effect of vacuum in the process is significant. The values of activation energy for the pyrolysis of individual components of easier devolatilization (volatiles and NR) are lower for pyrolysis under vacuum with a reduction of 12 K in the reaction starting temperature. The kinetic constant at 503 K for devolatilization of volatile additives at 0.25 atm is 1.7 times higher than that at 1 atm, and that corresponding to styrene-butadiene rubber at 723 K is 2.8 times higher. Vacuum enhances the volatilization and internal diffusion of products in the pyrolysis process, which contributes to attenuating the secondary reactions of the repolymerization and carbonization of these products on the surface of the char (carbon black). The higher quality of carbon black is interesting for process viability. The large-scale implementation of this process in continuous mode requires a comparison to be made between the economic advantages of using a vacuum and the energy costs, which will be lower when the technologies used for pyrolysis require a lower ratio between reactor volume and scrap tyre flow rate.

Lopez, Gartzen; Aguado, Roberto [Departamento de Ingenieria Quimica, Universidad del Pais Vasco, Apartado 644, 48080 Bilbao (Spain); Olazar, Martin [Departamento de Ingenieria Quimica, Universidad del Pais Vasco, Apartado 644, 48080 Bilbao (Spain)], E-mail: martin.olazar@ehu.es; Arabiourrutia, Miriam; Bilbao, Javier [Departamento de Ingenieria Quimica, Universidad del Pais Vasco, Apartado 644, 48080 Bilbao (Spain)

2009-10-15

271

A comprehensive aerosol spray method for the rapid photocatalytic grid area analysis of semiconductor photocatalyst thin films  

Microsoft Academic Search

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 10cm×10cm

Andreas Kafizas; Andrew Mills; Ivan P. Parkin

2010-01-01

272

Chemical Composition and Resistivity of Sprayed CuInS2 Thin Films for Solar Cells  

Microsoft Academic Search

CuInS2 thin films were prepared on glass substrates with the spray pyrolysis technique. The films were sprayed at 390degC using different ratios of x = [Cu] \\/ [In] in the aqueous solutions with the objective of studying their compositional, structural, optical and electrical properties. The values of the Cu\\/In ratio in the aqueous solutions have been changed in the range

J. M. Peza-Tapia; A. Morales-Acevedo; M. Ortega-Lopez

2007-01-01

273

Detection of segmentation cracks in top coat of thermal barrier coatings during plasma spraying by non-contact acoustic emission method  

NASA Astrophysics Data System (ADS)

Numerous cracks can be observed in the top coat of thermal barrier coatings (TBCs) deposited by the atmospheric plasma spraying (APS) method. These cracks can be classified into vertical and horizontal ones and they have opposite impact on the properties of TBCs. Vertical cracks reduce the residual stress in the top coat and provide strain tolerance. On the contrary, horizontal cracks trigger delamination of the top coat. However, monitoring methods of cracks generation during APS are rare even though they are strongly desired. Therefore, an in situ, non-contact and non-destructive evaluation method for this objective was developed in this study with the laser acoustic emission (AE) technique by using laser interferometers as a sensor. More AE events could be detected by introducing an improved noise reduction filter and AE event detection procedures with multiple thresholds. Generation of vertical cracks was successfully separated from horizontal cracks by a newly introduced scanning pattern of a plasma torch. Thus, generation of vertical cracks was detected with certainty by this monitoring method because AE events were detected only during spraying and a positive correlation was observed between the development degree of vertical cracks and the total AE energy in one experiment.

Ito, Kaita; Kuriki, Hitoshi; Araki, Hiroshi; Kuroda, Seiji; Enoki, Manabu

2014-06-01

274

Successful field trial of attractive toxic sugar bait (ATSB) plant-spraying methods against malaria vectors in the Anopheles gambiae complex in Mali, West Africa  

PubMed Central

Background Based on highly successful demonstrations in Israel that attractive toxic sugar bait (ATSB) methods can decimate local populations of mosquitoes, this study determined the effectiveness of ATSB methods for malaria vector control in the semi-arid Bandiagara District of Mali, West Africa. Methods Control and treatment sites, selected along a road that connects villages, contained man-made ponds that were the primary larval habitats of Anopheles gambiae and Anopheles arabiensis. Guava and honey melons, two local fruits shown to be attractive to An. gambiae s.l., were used to prepare solutions of Attractive Sugar Bait (ASB) and ATSB that additionally contained boric acid as an oral insecticide. Both included a color dye marker to facilitate determination of mosquitoes feeding on the solutions. The trial was conducted over a 38-day period, using CDC light traps to monitor mosquito populations. On day 8, ASB solution in the control site and ATSB solution in the treatment site were sprayed using a hand-pump on patches of vegetation. Samples of female mosquitoes were age-graded to determine the impact of ATSB treatment on vector longevity. Results Immediately after spraying ATSB in the treatment site, the relative abundance of female and male An. gambiae s.l. declined about 90% from pre-treatment levels and remained low. In the treatment site, most females remaining after ATSB treatment had not completed a single gonotrophic cycle, and only 6% had completed three or more gonotrophic cycles compared with 37% pre-treatment. In the control site sprayed with ASB (without toxin), the proportion of females completing three or more gonotrophic cycles increased from 28.5% pre-treatment to 47.5% post-treatment. In the control site, detection of dye marker in over half of the females and males provided direct evidence that the mosquitoes were feeding on the sprayed solutions. Conclusion This study in Mali shows that even a single application of ATSB can substantially decrease malaria vector population densities and longevity. It is likely that ATSB methods can be used as a new powerful tool for the control of malaria vectors, particularly since this approach is highly effective for mosquito control, technologically simple, inexpensive, and environmentally safe. PMID:20663142

2010-01-01

275

Structure and morphology of sprayed ZnS thin films  

Microsoft Academic Search

Zinc sulphide (ZnS) thin films have been prepared on Pyrex substrates by the spray pyrolysis technique using zinc chloride and thiourea as precursors. The depositions were carried out on substrates heated at 450 °C. The films were then annealed under sulphur atmosphere for one hour at 450 or 500 °C. This process allows one to obtain well-crystallized cubic-type -ZnS thin

T. Ben Nasrallah; M. Amlouk; J. C. Bernède; S. Belgacem

2004-01-01

276

Thermal Spraying Coatings Assisted by Laser Treatment  

NASA Astrophysics Data System (ADS)

Coatings produced by air plasma spraying (APS) are widely used to protect components against abrasive wear and corrosion. However, APS coatings contain porosities and the properties of these coatings may thereby be reduced. To improve these properties, various methods could be proposed, including post-laser irradiation [1-4]. Firstly, PROTAL process (thermal spraying assisted by laser) has been developed as a palliative technique to degreasing and grit-blasting prior to thermal spraying. Secondly, thermal spray coatings are densified and remelted using Laser treatment. In this study, a review of microstructure coatings prepared by laser-assisted air plasma spraying will be presented. Mechanical and magnetic properties will be evaluated in relation to changes in the coating microstructure and the properties of such coatings will be compared with those of as-sprayed APS coatings.

Fenineche, N. E.; Cherigui, M.

2008-09-01

277

Structural, Optical, and Electrical Characterization of Spray Pyrolysed Indium Sulfide Thin Films  

NASA Astrophysics Data System (ADS)

Indium sulfide (In2S3) thin films were deposited onto the glass substrates by a low cost simple spray pyrolysis technique at 300°C temperature. Aqueous solution of indium chloride and thiourea were used to deposit the binary In-S film. The deposited thin films were annealed at 400° and 500°C temperatures and characterized structurally, optically and electrically using EDX, X-ray diffraction, UV-visible spectroscopy and four probe van der Pauw methods. The optical constants such as refractive index and extinction coefficient are calculated from absorbance and transmittance data from 300 to 1100 nm wavelength. The optical transmittance increased after annealing at 400° and 500°C. The band gap energy was reduced from 2.90 to 2.50 eV after annealing the as deposited films. The electrical conductivity as well as the activation energy was increased after annealing the samples.

Rahman, F.; Podder, J.; Ichimura, M.

2013-04-01

278

Catalytic partial oxidation of pyrolysis oils  

NASA Astrophysics Data System (ADS)

This thesis explores the catalytic partial oxidation (CPO) of pyrolysis oils to syngas and chemicals. First, an exploration of model compounds and their chemistries under CPO conditions is considered. Then CPO experiments of raw pyrolysis oils are detailed. Finally, plans for future development in this field are discussed. In Chapter 2, organic acids such as propionic acid and lactic acid are oxidized to syngas over Pt catalysts. Equilibrium production of syngas can be achieved over Rh-Ce catalysts; alternatively mechanistic evidence is derived using Pt catalysts in a fuel rich mixture. These experiments show that organic acids, present in pyrolysis oils up to 25%, can undergo CPO to syngas or for the production of chemicals. As the fossil fuels industry also provides organic chemicals such as monomers for plastics, the possibility of deriving such species from pyrolysis oils allows for a greater application of the CPO of biomass. However, chemical production is highly dependent on the originating molecular species. As bio oil comprises up to 400 chemicals, it is essential to understand how difficult it would be to develop a pure product stream. Chapter 3 continues the experimentation from Chapter 2, exploring the CPO of another organic functionality: the ester group. These experiments demonstrate that equilibrium syngas production is possible for esters as well as acids in autothermal operation with contact times as low as tau = 10 ms over Rh-based catalysts. Conversion for these experiments and those with organic acids is >98%, demonstrating the high reactivity of oxygenated compounds on noble metal catalysts. Under CPO conditions, esters decompose in a predictable manner: over Pt and with high fuel to oxygen, non-equilibrium products show a similarity to those from related acids. A mechanism is proposed in which ethyl esters thermally decompose to ethylene and an acid, which decarbonylates homogeneously, driven by heat produced at the catalyst surface. Chapter 4 details the catalytic partial oxidation of glycerol without preheat: droplets of glycerol are sprayed directly onto the top of the catalyst bed, where they react autothermally with contact times on the order of tau ? 30 ms. The reactive flash volatilization of glycerol results in equilibrium syngas production over Rh-Ce catalysts. In addition, water can be added to the liquid glycerol, resulting in true autothermal reforming. This highly efficient process can increase H2 yields and alter the H2 to CO ratio, allowing for flexibility in syngas quality depending on the purpose. Chapter 5 details the results of a time on stream experiment, in which optimal syngas conditions are chosen. Although conversion is 100% for 450 hours, these experiments demonstrate the deactivation of the catalyst over time. Deactivation is exhibited by decreases in H2 and CO 2 production accompanied by a steady increase in CO and temperature. These results are explained as a loss of water-gas shift equilibration. SEM images suggest catalyst sintering may play a role; EDS indicates the presence of impurities on the catalyst. In addition, the instability of quartz in the reactor is demonstrated by etching, resulting in a hole in the reactor tube at the end of the experiment. These results suggest prevaporization may be desirable in this application, and that quartz is not a suitable material for the reactive flash volatilization of oxygenated fuels. In Chapter 6, pyrolysis oil samples from three sources - poplar, pine, and hardwoods - are explored in the context of catalytic partial oxidation. Lessons derived from the tests with model compounds are applied to reactor design, resulting in the reactive flash vaporization of bio oils. Syngas is successfully produced, though deactivation due to coke and ash deposition keeps H2 below equlibrium. Coke formation is observed on the reactor walls, but is avoided between the fuel injection site and catalyst by increasing the proximity of these in the reactor design. Low temperatures are maintained in the fuel delivery system utilizing a water-

Rennard, David Carl

2009-12-01

279

Thin layer chromatography-spray mass spectrometry: a method for easy identification of synthesis products and UV filters from TLC aluminum foils.  

PubMed

A straightforward procedure for direct mass spectrometric (MS) analysis of spots from thin layer chromatography (TLC) plates, without the need of an external ion source, was developed using the aluminum plate backing as spray tip. The spots were cut out shaped as a tip with a 60° angle, mounted in front of the MS orifice, and after addition of a spray solvent spectra were obtained immediately. A high-resolution time-of-flight MS was used since the method is of particular interest for rapid identification or confirmation of spots from TLC plates. The practical benefits of this technique were demonstrated by detection of by-products of organic reactions, by identification of degradation products, and by accurate confirmation of spots when UV filters in sunscreens were analyzed by TLC. Employing the described method TLC spots can be evaluated fast without the need of an external ion source or devices for analyte transfer from TLC to MS, only a basic MS instrument and a high-voltage power supply is required. PMID:24500757

Himmelsbach, Markus; Waser, Mario; Klampfl, Christian W

2014-06-01

280

Surface characteristic of chemically converted graphene coated low carbon steel by electro spray coating method for polymer electrolyte membrane fuel cell bipolar plate.  

PubMed

Graphene was coated on low carbon steel (SS400) by electro spray coating method to improve its properties of corrosion resistance and contact resistance. Exfoliated graphite was made of the graphite by chemical treatment (Chemically Converted Graphene, CCG). CCG is distributed using dispersing agent, and low carbon steel was coated with diffuse graphene solution by electro spray coating method. The structure of the CCG was analyzed using XRD and the coating layer of surface was analyzed using SEM. Analysis showed that multi-layered graphite structure was destroyed and it was transformed in to fine layers graphene structure. And the result of SEM analysis on the surface and the cross section, graphene layer was uniformly formed with 3-5 microm thickness on the surface of substrate. Corrosion resistance test was applied in the corrosive solution which is similar to the polymer electrolyte membrane fuel cell (PEMFC) stack inside. And interfacial contact resistance (ICR) test was measured to simulate the internal operating conditions of PEMFC stack. As a result of measuring corrosion resistance and contact resistance, it could be confirmed that low carbon steel coated with CCG was revealed to be more effective in terms of its applicability as PEMFC bipolar plate. PMID:23858864

Kim, Jungsoo; Kim, Yang Do; Nam, Dae Geun

2013-05-01

281

Comparison of properties of polymer organic solar cells prepared using highly conductive modified PEDOT:PSS films by spin- and spray-coating methods  

NASA Astrophysics Data System (ADS)

Bulk heterojunction (BHJ) solar cells have made great progress over the past decade and consequently are now attracting extensive academic and commercial interest because of their potential advantages: lightweight, flexible, low cost, and high-throughput production. Polymer conductivity is a key factor for improving the performance of electronic and photonic devices. Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is promising for use as a next-generation transparent electrode of optoelectronic devices. In this research, we compare the effect of nanomorphology on conductivity, and power conversion efficiency of polymer organic solar cells prepared by the spin- and spray-coating methods. To improve the conductivity of spray-deposited PEDOT:PSS, we modified the PEDOT:PSS films by simple UV irradiation and by UV irradiation with treatment using various solvents such as methanol, ethanol, acetone, acetonitrile, hydrochloric acid, and sulfuric acid to form a hole transport layer (HTL). The active layer of PTB7:PC70BM is spray-coated on top of the PEDOT:PSS layer. The films were examined by optical spectroscopy, micro-Raman spectroscopy, and conductivity measurements. The surface morphology of the deposited films was examined by atomic force microscopy (AFM). The current density-voltage (J-V) characteristics were measured under illumination with simulated solar light at 100 mW/cm2 (AM 1.5G) using an oriel 1000 W solar simulator. The obtained results are expected to have a considerable impact and suggest a bright future for organic polymer solar cells.

Kumar, Palanisamy; Santhakumar, Kannappan; Tatsugi, Jiro; Shin, Paik-Kyun; Ochiai, Shizuyasu

2014-01-01

282

Slow pyrolysis of pistachio shell  

Microsoft Academic Search

In this study, pistachio shell is taken as the biomass sample to investigate the effects of pyrolysis temperature on the product yields and composition when slow pyrolysis is applied in a fixed-bed reactor at atmospheric pressure to the temperatures of 300, 400, 500, 550, 700°C. The maximum liquid yield was attained at about 500–550°C with a yield of 20.5%. The

Esin Apaydin-Varol; Ersan Pütün; Ay?e E. Pütün

2007-01-01

283

Pyrolysis characteristics of the mixture of printed circuit board scraps and coal powder.  

PubMed

Thermogravimetric (TG) analysis and infrared spectroscopy were used to analyze the pyrolysis characteristics of printed circuit board scraps (PCBs), coal powder and their mixtures under nitrogen atmosphere. The experimental results show that there is a large difference between waste PCBs and coal powder in pyrolysis processing. The pyrolysis properties of the mixing samples are the result of interaction of the PCBs and coal powder, which is influenced by the content of mixture. The degree of pyrolysis and pyrolysis properties of the mixture are much better than that of the single component. The TG and the differential thermogravimetric (DTG) curves of the PCBs mixed with coal powder move towards the high-temperature zone with increasing amount of coal powder and subsequently the DTG peak also becomes wider. The Coats-Redfern integral method was used to determine the kinetic parameters of pyrolysis reaction mechanism with the different proportion of mixture. The gas of pyrolysis mainly composes of CO2, CO, H2O and some hydrocarbon. The bromide characteristic absorption peak has been detected obviously in the pyrolysis gas of PCBs. On the contrary, the absorption peak of the bromide is not obvious in pyrolysis gas of the PCBs samples adding 40% coal powder. PMID:24269060

Hao, Juan; Wang, Haifeng; Chen, Shuhe; Cai, Bin; Ge, Linhan; Xia, Wencheng

2014-10-01

284

Research on air sprays and unique foam application methods. Phase II report. Laboratory investigation of foam systems  

SciTech Connect

The objective of this study is to assess the effectiveness of air sprays and foam systems for dust control on longwall double-drum shearer faces. Laboratory testing has been conducted using foam systems and promising results have been obtained. Upon Bureau approval, underground testing will be scheduled to assess the effectiveness of foam systems under actual operating conditions. Laboratory testing of air sprays is being conducted at present. This report presents the results of the laboratory testing of foam systems. Specifically, the results obtained on the evaluation of selected foaming agents are presented, the feasibility investigation of flushing foam through the shearer-drum are demonstrated, and conceptual layout of the foam system on the shearer is discussed. The laboratory investigation of the selected foaming agents reveal that the Onyx Microfoam, Onyx Maprosyl and DeTer Microfoam foaming agents have higher expansion ratios compared to the others tested. Flushing foam through the shearer drum is entirely feasible and could be a viable technique for dust suppression on longwall faces.

Not Available

1982-06-01

285

Plasma Pyrolysis Assembly Regeneration Evaluation  

NASA Technical Reports Server (NTRS)

In April 2010 the Carbon Dioxide Reduction Assembly (CRA) was delivered to the International Space Station (ISS). This technology requires hydrogen to recover oxygen from carbon dioxide. This results in the production of water and methane. Water is electrolyzed to provide oxygen to the crew. Methane is vented to space resulting in a loss of valuable hydrogen and unreduced carbon dioxide. This is not critical for ISS because of the water resupply from Earth. However, in order to have enough oxygen for long-term missions, it will be necessary to recover the hydrogen to maximize oxygen recovery. Thus, the Plasma Pyrolysis Assembly (PPA) was designed to recover hydrogen from methane. During operation, the PPA produces small amounts of carbon that can ultimately reduce performance by forming on the walls and windows of the reactor chamber. The carbon must be removed, although mechanical methods are highly inefficient, thus chemical methods are of greater interest. The purpose of this effort was to determine the feasibility of chemically removing the carbon from the walls and windows of a PPA reactor using a pure carbon dioxide stream.

Medlen, Amber; Abney, Morgan B.; Miller, Lee A.

2011-01-01

286

Water content of pyrolysis oil: Comparison between Karl Fischer titration, GC\\/MS-corrected azeotropic distillation and 1H NMR spectroscopy  

Microsoft Academic Search

Pyrolysis converts biomass waste mainly into pyrolysis oil, which is a possible source of renewable energy and\\/or value-added chemicals. A very important characteristic of pyrolysis oil is its water content. Karl Fischer titration and azeotropic distillation by the Dean-Stark method are two common techniques for water determination. In this study, the water content is determined for several pyrolysis oil samples

K. Smets; P. Adriaensens; J. Vandewijngaarden; M. Stals; T. Cornelissen; S. Schreurs; R. Carleer; J. Yperman

2011-01-01

287

Structural, morphological, optical and photoluminescent properties of spray-deposited ZnSe thin film  

NASA Astrophysics Data System (ADS)

ZnSe thin films are successfully deposited by spray pyrolysis deposition technique. Deposited thin films are characterized by X-ray diffraction study, and it reveals that spray-deposited ZnSe thin films are polycrystalline with hexagonal crystal structure. Surface morphology is carried out by scanning electron microscopy. It shows cotton-like morphology, and optical properties, such as absorbance, transmittance, reflectance, band gap, refractive index, extinction coefficient are studied. Photoluminescence shows strong emission at 497 nm. Also, spray-deposited ZnSe thin films are hydrophilic in nature, which is shown by contact angle meter.

Lohar, G. M.; Shinde, S. K.; Fulari, V. J.

2014-11-01

288

Effect of deposition temperature on structural and optical properties of sprayed nickel oxide thin films  

NASA Astrophysics Data System (ADS)

NiO thin films were prepared by spray pyrolysis technique on preheated glass substrate. The effect of deposition temperature on the structural, morphological and optical properties was studied by XRD, AFM and UV-visible spectrophotometer. XRD analysis indicated polycrystalline cubic structure of sprayed films with (111) preferred orientation. It has been found that optical absorption behavior and surface morphology of the films can be controlled by substrate temperature. UV-visible spectra shows that the absorption edges of sprayed films shift to short wavelength with increasing deposition temperature.

Sharma, R.; Acharya, A. D.; Moghe, Shweta; Shrivastava, S. B.; Ganesan, V.

2013-06-01

289

Experimental Research of Pyrolysis Gases Cracking on Surface of Charcoal  

NASA Astrophysics Data System (ADS)

For several years, in the Joint Institute for High Temperatures of Russian Academy of Sciences, two-stage technology of biomass processing has been developing [1]. The technology is based on pyrolysis of biomass as the first stage. The second stage is high-temperature conversion of liquid fraction of the pyrolysis on the surface of porous charcoal matrix. Synthesis gas consisted of carbon monoxide and hydrogen is the main products of the technology. This gas is proposed to be used as fuel for gas-engine power plant. For practical implementation of the technology it is important to know the size of hot char filter for full cracking of the pyrolysis gases on the surface of charcoal. Theoretical determination of the cracking parameters of the pyrolysis gases on the surface of coal is extremely difficult because the pyrolysis gases include tars, whose composition and structure is complicated and depends on the type of initial biomass. It is also necessary to know the surface area of the char used in the filter, which is also a difficult task. Experimental determination of the hot char filter parameters is presented. It is shown that proposed experimental method can be used for different types of biomass.

Kosov, Valentin; Kosov, Vladimir; Zaichenko, Victor

290

soluble fish proteins obtained by enzymatic treatment of fresh fish offals dried according to the Hatmaker or Spray methods. Six artificial milks were made by dry pelleting of either cow skim-  

E-print Network

to the Hatmaker or Spray methods. Six artificial milks were made by dry pelleting of either cow skim- milk powder into the feeds containing fish concentrates. The milk substitutes were offered between i2 and 35 days of age gain generally decreased when the substitution rate of milk proteins by fish proteins increased

Boyer, Edmond

291

The effect of educating the use of spray by visual concept mapping method on the quality of life of children with asthma.  

PubMed

One of the most important goals in treating chronic diseases, especially asthma, is the promotion of quality of life (QOL). The present study aimed at identifying the effect of educating method on the QOL of children, who suffered from asthma.In this clinical trial study, 80 children aged 6-12 years with asthma were divided into two groups: control (face-to-face method) and experimental (visual concept mapping method). The QOL of both groups was measured before and after educating by the Juniper's Quality of Life Questionnaire with a one-month interval.The rate of change in the QOL score of the experimental group was 0.3 (±0.7) both before and after intervention and 0.1 (±0.3) in the control group, which was statistically significant (p<0.05).Educating by the visual concept mapping method with regard to the manner of using sprays is taken into account as an efficient and effective method in improving the QOL of children with asthma. PMID:23454780

Bozorgzad, Parisa; Ebadi, Abbas; Moin, Mostafa; Sarhangy, Forough; Nasiripour, Somayyeh; Soleimani, Mohammad Ali

2013-03-01

292

Microstructural and macroscopic properties of cold sprayed copper coatings  

NASA Astrophysics Data System (ADS)

Cold spraying is a coating technique in which the formation of dense, tightly bonded coatings occurs only due to the kinetic energy of high velocity particles of the spray powder. These particles are still in the solid state as they impinge on the substrate. This study correlates optimized deposition parameters with the corresponding microstructure as well as mechanical and conductive behavior of cold sprayed copper coatings in order to explain possible bonding mechanisms. In addition, the performance of cold sprayed copper coatings is compared to that of cold rolled copper and to coatings prepared by thermal spray methods.

Borchers, C.; Gärtner, F.; Stoltenhoff, T.; Assadi, H.; Kreye, H.

2003-06-01

293

Initial Stages of Pyrolysis of Polyethylene  

NASA Astrophysics Data System (ADS)

Combustion and flammability of plastics are important topics of practical interest directly related to fire safety and recycling of polymeric materials; pyrolysis of the solid is the initial step of its combustion. One of the main ways to study such complicated processes is through detailed mechanistic modeling, in which the process is represented by a set of many elementary reactions. Mechanistic modeling of combustion of plastics is considerably hindered by the lack of necessary kinetic data. In virtually all existing models of polymer pyrolysis the majority of kinetic data used are derived from the corresponding gas phase values of smaller species. The use of gas phase rate constants is, generally, not justified without an experimental justification. In the first part of the work the influence of condensed phase on the rate of scission of a carbon-carbon bond (the reaction that initiates pyrolysis and combustion) in polyethylene (PE) was studied using the method of Reactive Molecular Dynamics (RMD). A method based on a two-step kinetic mechanism was developed to decouple the cage effect from the kinetics of the reaction under study. It was observed that under the conditions of condensed phase the rate constant of C-C bond scission in PE decreased by an order of magnitude compared to that obtained in vacuum. It was also shown that under the conditions of polymer melt the rate constant does not depend on the length of the polymer chain. In the second part of the work the kinetics of liquid phase and gas phase products of PE pyrolysis were studied experimentally using Gas Chromatography and Nuclear Magnetic Resonance. Based on the assumption of applicability of gas phase kinetic data for C-C scission reaction and beta-scission reaction under the conditions of polymer melt, rate constants of hydrogen transfer, radical addition to double bonds, and radical recombination were determined via kinetic modeling of the experimental results. The obtained values of the rate constants were found to be in reasonable agreement with the constants of similar reactions of smaller molecules in the gas phase.

Popov, Konstantin V.

294

Comparative pyrolysis and combustion kinetics of oil shales  

Microsoft Academic Search

In this research, thermal characteristics and kinetic parameters of eight Turkish oil shale samples were determined by thermogravimetry (TG\\/DTG) at non-isothermal heating conditions both for pyrolysis and combustion processes. A general computer program was developed and the methods are compared with regard to their accuracy and the ease of interpretation of the kinetics of thermal decomposition. Activation energies of the

Mustafa Versan Kök; M. Reha Pamir

2000-01-01

295

Plasma-Sprayed Coatings on Porous Surfaces  

NASA Technical Reports Server (NTRS)

Need for combining benefits of duplex thermal-barrier coatings with film cooling on gas-turbine vanes and blades stimulated development of improved method for plasma spraying these coatings. Method reduces blocking of holes by plasma-sprayed material and at same time reduces base-metal oxidation during coating operation. Features provide potential for increased engine efficiency and power, reduced fuel consumption, use of less costly materials or construction procedures, and extended life and durability.

Leibert, C. H.

1986-01-01

296

Simplifying pyrolysis; using gasification to produce corn stover and wheat straw biochar for sorptive and horitcultural media  

Technology Transfer Automated Retrieval System (TEKTRAN)

Biochar is a renewable, useful material that can be utilized in many different applications. Biochar is commonly produced via pyrolysis methods using a retort-style oven with inert gas. Gasification is another method that can utilize pyrolysis to produce biochar, but with the advantage of not requir...

297

Vacuum pyrolysis of used tires  

SciTech Connect

The vacuum pyrolysis of used tires enables the recovery of useful products, such as pyrolytic oil and pyrolytic carbon black (CB{sub P}). The light part of the pyrolytic oil contains dl-limonene which has a high price on the market. The naphtha fraction can be used as a high octane number component for gasoline. The middle distillate demonstrated mechanical and lubricating properties similar to those of the commercial aromatic oil Dutrex R 729. The heavy oil was tested as a feedstock for the production of needle coke. It was found that the surface morphology of CB{sub P} produced by vacuum pyrolysis resembles that of commercial carbon black. The CB{sub P} contains a higher concentration of inorganic compounds (especially ZnO and S) than commercial carbon black. The pyrolysis process feasibility looks promising. One old tire can generate upon vacuum pyrolysis, incomes of at least $2.25 US with a potential of up to $4.83 US/tire upon further product improvement. The process has been licensed to McDermott Marketing Servicing Inc. (Houston) for its exploitation in the US.

Roy, C.; Darmstadt, H.; Benallal, B.; Chaala, A.; Schwerdtfeger, A.E. [Univ. Laval, Quebec City, Quebec (Canada). Dept. de Geneie Chimique

1995-11-01

298

A simple and sensitive gas chromatography method for determination of isosorbide dinitrate and its metabolites in human plasma: application to pharmacokinetics study on oral spray.  

PubMed

A sensitive method for the simultaneous determination of isosorbide dinitrate (ISDN) and its mononitrate metabolites, isosorbide 2-mononitrate and isosorbide 5-mononitrate (IS-2-MN and IS-5-MN), in human plasma was developed using capillary gas chromatography with electron-capture detection, whereas 1,2,4-butanetriol trinitrate was used as internal standard. The analytes were extracted with a simple liquid-liquid extraction from plasma and separated on a DB-1 column. The results of method validation demonstrated that the calibration curves were linear in range of 2-60?ng/mL for ISDN and IS-5-MN, 1-20?ng/mL for IS-2-MN, respectively. The precision (RSD%) was less than 15%, and the lower limit of quantitation was identifiable and reproducible at 2?ng/mL for ISDN and IS-5-MN, 1?ng/mL for IS-2-MN. The analytes in plasma were stable after being stored for more than 30 days and after 2 freeze-thaw cycles (-20 to 25°C). And then this method was successfully applied to a pharmacokinetic investigation on isosorbide dinitrate oral spray in healthy volunteers. PMID:23904215

Jiang, Z; Wei, C; Sun, Z; Guo, J; Li, R; Zhang, R; Yuan, G; Guo, R

2014-02-01

299

Bear Spray Safety Program  

USGS Publications Warehouse

A bear spray safety program for the U.S. Geological Survey (USGS) was officially initiated by the Firearms Safety Committee to address accident prevention and to promote personnel training in bear spray and its transportation, storage, and use for defense against wild animals. Used as part of a system including firearms, or used alone for those who choose not to carry a firearm, bear spray is recognized as an effective tool that can prevent injury in a wild animal attack.

Blome, C.D.; Kuzniar, R.L.

2009-01-01

300

Numerical parametric studies of spray combustion instability  

NASA Technical Reports Server (NTRS)

A coupled numerical algorithm has been developed for studies of combustion instabilities in spray-driven liquid rocket engines. The model couples gas and liquid phase physics using the method of fractional steps. Also introduced is a novel, efficient methodology for accounting for spray formation through direct solution of liquid phase equations. Preliminary parametric studies show marked sensitivity of spray penetration and geometry to droplet diameter, considerations of liquid core, and acoustic interactions. Less sensitivity was shown to the combustion model type although more rigorous (multi-step) formulations may be needed for the differences to become apparent.

Pindera, M. Z.

1993-01-01

301

Studies on dynamic IV curves of semiconductor-liquid junction cells formed with Cd 0·8 Zn 0·2 S films prepared at various spray rates  

Microsoft Academic Search

Cd0·8Zn0·2S films were prepared by the spray pyrolysis technique on glass and conducting glass (fluorine doped tin oxide) substrates,\\u000a by spraying aqueous solutions of cadmium chloride, zinc chloride and thiourea. The spray rate was varied from 4 cc\\/min to\\u000a 16 cc\\/min. It is found that film thickness increases with increase in spray rate. The electrical and optical properties of\\u000a the

M D Uplane; S H Pawar

1985-01-01

302

LSPRAY-IV: A Lagrangian Spray Module  

NASA Technical Reports Server (NTRS)

LSPRAY-IV is a Lagrangian spray solver developed for application with parallel computing and unstructured grids. It is designed to be massively parallel and could easily be coupled with any existing gas-phase flow and/or Monte Carlo Probability Density Function (PDF) solvers. The solver accommodates the use of an unstructured mesh with mixed elements of either triangular, quadrilateral, and/or tetrahedral type for the gas flow grid representation. It is mainly designed to predict the flow, thermal and transport properties of a rapidly vaporizing spray. Some important research areas covered as a part of the code development are: (1) the extension of combined CFD/scalar-Monte- Carlo-PDF method to spray modeling, (2) the multi-component liquid spray modeling, and (3) the assessment of various atomization models used in spray calculations. The current version contains the extension to the modeling of superheated sprays. The manual provides the user with an understanding of various models involved in the spray formulation, its code structure and solution algorithm, and various other issues related to parallelization and its coupling with other solvers.

Raju, M. S.

2012-01-01

303

A Novel Energy-Efficient Pyrolysis Process: Self-pyrolysis of Oil Shale Triggered by Topochemical Heat in a Horizontal Fixed Bed  

PubMed Central

This paper proposes a novel energy-efficient oil shale pyrolysis process triggered by a topochemical reaction that can be applied in horizontal oil shale formations. The process starts by feeding preheated air to oil shale to initiate a topochemical reaction and the onset of self-pyrolysis. As the temperature in the virgin oil shale increases (to 250–300°C), the hot air can be replaced by ambient-temperature air, allowing heat to be released by internal topochemical reactions to complete the pyrolysis. The propagation of fronts formed in this process, the temperature evolution, and the reaction mechanism of oil shale pyrolysis in porous media are discussed and compared with those in a traditional oxygen-free process. The results show that the self-pyrolysis of oil shale can be achieved with the proposed method without any need for external heat. The results also verify that fractured oil shale may be more suitable for underground retorting. Moreover, the gas and liquid products from this method were characterised, and a highly instrumented experimental device designed specifically for this process is described. This study can serve as a reference for new ideas on oil shale in situ pyrolysis processes. PMID:25656294

Sun, You-Hong; Bai, Feng-Tian; Lü, Xiao-Shu; Li, Qiang; Liu, Yu-Min; Guo, Ming-Yi; Guo, Wei; Liu, Bao-Chang

2015-01-01

304

A Novel Energy-Efficient Pyrolysis Process: Self-pyrolysis of Oil Shale Triggered by Topochemical Heat in a Horizontal Fixed Bed.  

PubMed

This paper proposes a novel energy-efficient oil shale pyrolysis process triggered by a topochemical reaction that can be applied in horizontal oil shale formations. The process starts by feeding preheated air to oil shale to initiate a topochemical reaction and the onset of self-pyrolysis. As the temperature in the virgin oil shale increases (to 250-300°C), the hot air can be replaced by ambient-temperature air, allowing heat to be released by internal topochemical reactions to complete the pyrolysis. The propagation of fronts formed in this process, the temperature evolution, and the reaction mechanism of oil shale pyrolysis in porous media are discussed and compared with those in a traditional oxygen-free process. The results show that the self-pyrolysis of oil shale can be achieved with the proposed method without any need for external heat. The results also verify that fractured oil shale may be more suitable for underground retorting. Moreover, the gas and liquid products from this method were characterised, and a highly instrumented experimental device designed specifically for this process is described. This study can serve as a reference for new ideas on oil shale in situ pyrolysis processes. PMID:25656294

Sun, You-Hong; Bai, Feng-Tian; Lü, Xiao-Shu; Li, Qiang; Liu, Yu-Min; Guo, Ming-Yi; Guo, Wei; Liu, Bao-Chang

2015-01-01

305

Fixed-bed pyrolysis of safflower seed: influence of pyrolysis parameters on product yields and compositions  

Microsoft Academic Search

Fixed-bed slow pyrolysis experiments have been conducted on a sample of safflower seed to determine particularly the effects of pyrolysis temperature, heating rate, particle size and sweep gas flow rate on the pyrolysis product yields and their chemical compositions. The maximum oil yield of 44% was obtained at the final pyrolysis temperature of 500°C, particle size range of +0.425–1.25 mm,

S. H. Beis; Ö. Onay; Ö. M. Koçkar

2002-01-01

306

Spray measurement technology: a review  

NASA Astrophysics Data System (ADS)

Sprays are among the most intellectually challenging and practically important topics in fluid mechanics. This paper reviews needs, milestones, challenges, and a broad array of techniques for spray measurement. In addition, tabular summaries provide cross-referenced entry points to the vast literature by organizing over 300 citations according to key spray phenomena, physical parameters and measurement techniques for each of the principal spray regions (nozzle internal flow, near-field spray-formation region, far-field developed spray, and spray-wall interaction). The article closes with perspectives on some current issues in spray research, including the cost and complexity of apparatus for spray physics and spray engineering, the need for simultaneous diagnostic measurements under application-relevant conditions, and the effective comparison of spray measurements and numerical simulations.

Fansler, Todd D.; Parrish, Scott E.

2015-01-01

307

A simplified model of aerosol removal by containment sprays  

SciTech Connect

Spray systems in nuclear reactor containments are described. The scrubbing of aerosols from containment atmospheres by spray droplets is discussed. Uncertainties are identified in the prediction of spray performance when the sprays are used as a means for decontaminating containment atmospheres. A mechanistic model based on current knowledge of the physical phenomena involved in spray performance is developed. With this model, a quantitative uncertainty analysis of spray performance is conducted using a Monte Carlo method to sample 20 uncertain quantities related to phenomena of spray droplet behavior as well as the initial and boundary conditions expected to be associated with severe reactor accidents. Results of the uncertainty analysis are used to construct simplified expressions for spray decontamination coefficients. Two variables that affect aerosol capture by water droplets are not treated as uncertain; they are (1) {open_quote}Q{close_quote}, spray water flux into the containment, and (2) {open_quote}H{close_quote}, the total fall distance of spray droplets. The choice of values of these variables is left to the user since they are plant and accident specific. Also, they can usually be ascertained with some degree of certainty. The spray decontamination coefficients are found to be sufficiently dependent on the extent of decontamination that the fraction of the initial aerosol remaining in the atmosphere, m{sub f}, is explicitly treated in the simplified expressions. The simplified expressions for the spray decontamination coefficient are given. Parametric values for these expressions are found for median, 10 percentile, and 90 percentile values in the uncertainty distribution for the spray decontamination coefficient. Examples are given to illustrate the utility of the simplified expressions to predict spray decontamination of an aerosol-laden atmosphere.

Powers, D.A. [Sandia National Labs., Albuquerque, NM (US); Burson, S.B. [Nuclear Regulatory Commission, Washington, DC (US). Div. of Safety Issue Resolution

1993-06-01

308

A simplified model of aerosol removal by containment sprays  

SciTech Connect

Spray systems in nuclear reactor containments are described. The scrubbing of aerosols from containment atmospheres by spray droplets is discussed. Uncertainties are identified in the prediction of spray performance when the sprays are used as a means for decontaminating containment atmospheres. A mechanistic model based on current knowledge of the physical phenomena involved in spray performance is developed. With this model, a quantitative uncertainty analysis of spray performance is conducted using a Monte Carlo method to sample 20 uncertain quantities related to phenomena of spray droplet behavior as well as the initial and boundary conditions expected to be associated with severe reactor accidents. Results of the uncertainty analysis are used to construct simplified expressions for spray decontamination coefficients. Two variables that affect aerosol capture by water droplets are not treated as uncertain; they are (1) [open quote]Q[close quote], spray water flux into the containment, and (2) [open quote]H[close quote], the total fall distance of spray droplets. The choice of values of these variables is left to the user since they are plant and accident specific. Also, they can usually be ascertained with some degree of certainty. The spray decontamination coefficients are found to be sufficiently dependent on the extent of decontamination that the fraction of the initial aerosol remaining in the atmosphere, m[sub f], is explicitly treated in the simplified expressions. The simplified expressions for the spray decontamination coefficient are given. Parametric values for these expressions are found for median, 10 percentile, and 90 percentile values in the uncertainty distribution for the spray decontamination coefficient. Examples are given to illustrate the utility of the simplified expressions to predict spray decontamination of an aerosol-laden atmosphere.

Powers, D.A. (Sandia National Labs., Albuquerque, NM (United States)); Burson, S.B. (Nuclear Regulatory Commission, Washington, DC (United States). Div. of Safety Issue Resolution)

1993-06-01

309

Study of TEOS and TPOS anticorrosion coatings developed at different ranges of pyrolysis temperatures  

NASA Astrophysics Data System (ADS)

Anticorrosion coatings were produced by spraying pure simple silane compounds, either tetraethoxysilane (TEOS) or tetraphenoxysilane (TPOS), in a preheated furnace on specimens of carbon steel alloy. These specimens were thermally decomposed over various temperature ranges, covering a total temperature range of 20-1050 °C. This temperature range was divided into four sectors. The specific functions of each of these sectors were described as: hydrolysis (20-50 °C), low pyrolysis (50-250 °C), middle pyrolysis (250-750 °C), and high pyrolysis (750-1050 °C). SEM, ultrasonic vibration (USV), plane-cross polarized microscope, micro-hardness tester, XRD, and cyclic voltammography were utilized for analysis of the produced coatings. A comparison study between the anticorrosion coatings produced using TEOS or TPOS was targeted to evaluate two aspects. The first was the microstructure morphologies and corresponding variations of the chemical constituents and textural surfaces of the TEOS and TPOS coating materials at the selected pyrolysis temperature ranges. The second was the property of the TEOS and TPOS anticorrosion coating materials producing minimal decay for electrochemical protection of carbon steel alloy against corrosion under low and high acidic conditions.

Hashem, Khaled M. E.

2003-07-01

310

Pyrolysis process for producing fuel gas  

NASA Technical Reports Server (NTRS)

Solid waste resource recovery in space is effected by pyrolysis processing, to produce light gases as the main products (CH.sub.4, H.sub.2, CO.sub.2, CO, H.sub.2O, NH.sub.3) and a reactive carbon-rich char as the main byproduct. Significant amounts of liquid products are formed under less severe pyrolysis conditions, and are cracked almost completely to gases as the temperature is raised. A primary pyrolysis model for the composite mixture is based on an existing model for whole biomass materials, and an artificial neural network models the changes in gas composition with the severity of pyrolysis conditions.

Serio, Michael A. (Inventor); Kroo, Erik (Inventor); Wojtowicz, Marek A. (Inventor); Suuberg, Eric M. (Inventor)

2007-01-01

311

Pyrolysis processing for solid waste resource recovery  

NASA Technical Reports Server (NTRS)

Solid waste resource recovery in space is effected by pyrolysis processing, to produce light gases as the main products (CH.sub.4, H.sub.2, CO.sub.2, CO, H.sub.2O, NH.sub.3) and a reactive carbon-rich char as the main byproduct. Significant amounts of liquid products are formed under less severe pyrolysis conditions, and are cracked almost completely to gases as the temperature is raised. A primary pyrolysis model for the composite mixture is based on an existing model for whole biomass materials, and an artificial neural network models the changes in gas composition with the severity of pyrolysis conditions.

Serio, Michael A. (Inventor); Kroo, Erik (Inventor); Wojtowicz, Marek A. (Inventor); Suuberg, Eric M. (Inventor)

2007-01-01

312

Physicochemical Characterization and In Vivo Evaluation of Amorphous and Partially Crystalline Calcium Phosphate Coatings Fabricated on Ti-6Al-4V Implants by the Plasma Spray Method  

PubMed Central

Objective. To characterize the topographic and chemical properties of 2 bioceramic coated plateau root form implant surfaces and evaluate their histomorphometric differences at 6 and 12 weeks in vivo. Methods. Plasma sprayed hydroxyapatite (PSHA) and amorphous calcium phosphate (ACP) surfaces were characterized by scanning electron microscopy (SEM), interferometry (IFM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). Implants were placed in the radius epiphysis, and the right limb of dogs provided implants that remained for 6 weeks, and the left limb provided implants that remained 12 weeks in vivo. Thin sections were prepared for bone-to-implant contact (BIC) and bone-area-fraction occupancy (BAFO) measurements (evaluated by Friedman analysis P < 0.05). Results. Significantly, higher Sa (P < 0.03) and Sq (P < 0.02) were observed for ACP relative to PSHA. Chemical analysis revealed significantly higher HA, calcium phosphate, and calcium pyrophosphate for the PSHA surface. BIC and BAFO measurements showed no differences between surfaces. Lamellar bone formation in close contact with implant surfaces and within the healing chambers was observed for both groups. Conclusion. Given topographical and chemical differences between PSHA and ACP surfaces, bone morphology and histomorphometric evaluated parameters showed that both surfaces were osseoconductive in plateau root form implants. PMID:22969806

Bonfante, Estevam A.; Witek, Lukasz; Tovar, Nick; Suzuki, Marcelo; Marin, Charles; Granato, Rodrigo; Coelho, Paulo G.

2012-01-01

313

Spray drift mitigation with spray mix adjuvants  

Technology Transfer Automated Retrieval System (TEKTRAN)

Numerous drift reduction adjuvants and spray deposition aids are available to applicators of crop production and protection chemicals. Performance of many of the newly introduced drift control adjuvants has not been well documented for aerial application. Four new drift control adjuvants were sele...

314

Parameters for the Pyrolysis of Organic Material - Perchlorate Mixtures  

NASA Astrophysics Data System (ADS)

The ESA-lead Mars rover ExoMars (launch in 2018) will carry a suit of instruments, one of the in-struments is the Mars Organic Molecule Analyzer MOMA. Organic material in the Martian soil will be either pyrolyzed at temperatures of up to 1000°C and separated by gas chromatography or volatilized with the help of an UV-laser. A mass spectrometer will be the detector for both methods. Chlorinated organics have been detected in pyroly-sis GC-MS experiments on Mars two times. The first time during the Viking mission in 1976 and a second time with the Sample Analysis on Mars (SAM) in-strument onboard the Curiosity rover in 2012. [1] [2] The presence of perchlorates found by the Phoenix mission in 2008 [3] lead to the discovery that organic molecules not only get oxidized during pyrolysis, but also chlorinated organic compounds can be pro-duced. [4] The parameters used for pyrolysis and the sample composition especially the distribution of organics and perchlorates within the sample and the concentrations of organics and perchlorate have a huge influence on the products created. It is possible to change the condi-tions of the pyrolysis by spatially separating the organ-ics from the perchlorates that the chloromethanes get the major product of the pyrolysis. This might help to understand the results of the (SAM) instrument yield-ing mono-, di- and trichloromethane and a chlorinated 4-hydrocarbon molecule. References: [1] Biemann K et al. (1977) JGR, 82, 4641-4658. [2] Grotzinger J. P et al. (2011) AGU Fall Meeting U13A-01 [3] Hecht M. H., et al. (2009) Science, 325 64-67. [4] Steininger H., Goesmann F., Goetz W. (2011) Planet. & Space Sci., 71, 9-17. Acknowledgments: This work was funded by DLR (FKZ 50QX1001)

Steininger, Harald; Goesmann, Fred; Goetz, Walter

2013-04-01

315

Efficient spray-coated colloidal quantum dot solar cells.  

PubMed

A colloidal quantum dot solar cell is fabricated by spray-coating under ambient conditions. By developing a room-temperature spray-coating technique and implementing a fully automated process with near monolayer control-an approach termed as sprayLD-an electronic defect is eliminated resulting in solar cell performance and statistical distribution superior to prior batch-processed methods along with a hero performance of 8.1%. PMID:25382752

Kramer, Illan J; Minor, James C; Moreno-Bautista, Gabriel; Rollny, Lisa; Kanjanaboos, Pongsakorn; Kopilovic, Damir; Thon, Susanna M; Carey, Graham H; Chou, Kang Wei; Zhitomirsky, David; Amassian, Aram; Sargent, Edward H

2015-01-01

316

High mass throughput particle generation using multiple nozzle spraying  

DOEpatents

Spraying apparatus and methods that employ multiple nozzle structures for producing multiple sprays of particles, e.g., nanoparticles, for various applications, e.g., pharmaceuticals, are provided. For example, an electrospray dispensing device may include a plurality of nozzle structures, wherein each nozzle structure is separated from adjacent nozzle structures by an internozzle distance. Sprays of particles are established from the nozzle structures by creating a nonuniform electrical field between the nozzle structures and an electrode electrically isolated therefrom.

Pui, David Y. H. (Plymouth, MN); Chen, Da-Ren (Creve Coeur, MO)

2009-03-03

317

Plasma Spray System  

NASA Technical Reports Server (NTRS)

Computer aided, fully-automatic TRW system sprays very hot plasma onto a turbine blade. Composed of gas into which metallic and ceramic powders have been injected, the plasma forms a two-layer coating which insulates the blade. Critical part of operation is controlling the thickness of the deposit which is measured in thousandths of an inch. This is accomplished by an optical detector which illuminates spots at various locations on the blade and determines thickness by measuring the light reflections. Optical sensor monitors spraying process until precise thickness is attained, then computer halts the spraying.

1980-01-01

318

Full containment spray drying  

SciTech Connect

Aspects of safety, environmental protection, and powder quality will continue to influence advances within spray dryer design and operation, and the concept of full containment spray drying offers a means to meet future industrial requirements. Process air recycle and powder containment within the drying chamber leads to no process air discharge to atmosphere, provides a more favorable operator environment around the spray dryer installation, reduces regions within the dryer layout where potential explosive powder/air mixtures can exist, improves yields, reduces powder losses, and provides easier cleaning operations with reduced wash water requirements.

Masters, K.

1999-11-01

319

Pyrolysis of humic and fulvic acids  

USGS Publications Warehouse

Pyrolysis of humic and fulvic acids isolated from a North Carolina soil yields a variety of aromatic, heterocyclic and straight chain organ compounds. The pyrolysis products identified by gas chromatography and mass spectrometry indicate that humic and fulvic acids have aromatic and polysaccharide structures in their molecules. ?? 1969.

Wershaw, R.L.; Bohner, G.E., Jr.

1969-01-01

320

General kinetic model of oil shale pyrolysis  

Microsoft Academic Search

A mathematical model for pyrolysis of Green River oil shale is developed from previous experiments on oil, water, and gas evolution and oil cracking over a wide range of pyrolysis conditions. Reactions included are evolution of 5 gas species, oil, and water from kerogen, clay dehydration, oil coking and cracking, and evolution of Hâ and CHâ from char. Oil is

Alan K. Burnham; Robert L. Braun

1985-01-01

321

Preparation, characterizations and CO sensing performance of chemically sprayed nanostructured SnO2 thin films  

NASA Astrophysics Data System (ADS)

Thin films of nanostructured SnO2 were prepared using simple chemical spray pyrolysis technique. As prepared thin films were characterized using the XRD and FE-SEM technique. The average grain size was observed to be less than 48 nm. These films were observed to most sensitive (S = 180.81) to CO for 100 ppm at 300°C. The sensor shows quick response (3 s) and recovery (8 s).

Bari, R. H.

2013-06-01

322

Photoluminescence studies on off-stoichiometric defects in sprayed CZTS thin films  

NASA Astrophysics Data System (ADS)

Photoluminescence (PL) technique was used for studying the defects in Copper Zinc Tin Sulphide (CZTS) thin films deposited by Chemical Spray Pyrolysis (CSP). Measurements were done on films prepared for different Cu:Zn:Sn:S ratios. An emission at 0.805 eV was monitored from 15 K to room temperature and activation energy was calculated. Excitation power dependent studies were done to analyze the type of transition.

Poornima, N.; Rajeshmon, V. G.; Kartha, C. Sudha; Vijayakumar, K. P.

2014-04-01

323

Tl-based superconducting films prepared by aerosol spray deposition and thallinated in an open system  

Microsoft Academic Search

Superconducting Tl-based films were prepared on a LaAlO3 single crystal substrate. Spray pyrolysis of Ba, Ca and Cu nitrate solutions was used for deposition of the precursor films.\\u000a They were subsequently ex-situ thallinated in flowing oxygen (open system). While the superconducting Tl-2212 phase formed at an annealing temperature\\u000a of 880°C, thallination at 900°C led to the formation of a Tl-2223

Zuzana Matkovicová; Vladimír Štrbík; Gustav Plesch; Michaela Valeriánová; Agáta Dujavová

2007-01-01

324

Microstructure and cathodoluminescence study of sprayed Al and Sn doped ZnS thin films  

Microsoft Academic Search

Here we report on the study of ZnS and X-doped ZnS (with 4 at% of X = Al, Sn) thin films, prepared by spray pyrolysis technique using chloride precursors. Cathodoluminescence imaging and spectroscopy, x-ray diffraction, x-ray energy dispersive spectrometry and spectrophotometry have been used for their characterization. Deposited at their optimal substrate temperature (Ts = 773 K), these films are

A. El Hichou; M. Addou; J. L. Bubendorff; J. Ebothé; B. El Idrissi; M. Troyon

2004-01-01

325

Sensing low concentrations of CO using flame-spray-made Pt\\/SnO 2 nanoparticles  

Microsoft Academic Search

Tin dioxide nanoparticles of different sizes and platinum doping contents were synthesized in one step using the flame spray\\u000a pyrolysis (FSP) technique. The particles were used to fabricate semiconducting gas sensors for low level CO detection, i.e.\\u000a with a CO gas concentration as low as 5 ppm in the absence and presence of water. Post treatment of the SnO2 nanoparticles was

L. Mädler; T. Sahm; A. Gurlo; J.-D. Grunwaldt; N. Barsan; U. Weimar; S. E. Pratsinis

2006-01-01

326

Formation of dl-limonene in used tire vacuum pyrolysis oils. [dipentene  

SciTech Connect

Tire recycling has become an important environmental issue recently due to the huge piles of tires that threaten the environment. Thermal decomposition of tire, a synthetic rubber material, enables the recovery of carbon black and liquid hydrocarbon oils. Both have potential economic values. Pyrolysis oils obtained under vacuum conditions contain a significant portion of a volatile, naptha-like fraction with an octane number similar to petroleum naphtha fraction, in addition, contains approximately 15% limonene. Potential applications of vacuum pyrolysis oil and carbon black have been investigated. However, the process economics is greatly influenced by the quality of the oil and carbon black products. This paper discusses limonene formation during used tire vacuum pyrolysis and its postulated reaction mechanism. The limonene separation method from pyrolysis oil, as well as its purification in laboratory scale, and structural characterization are discussed. Large-scale limonene separation and purification is under investigation.

Pakdel, H.; Roy, C.; Aubin, H.; Jean, G. (Univ. Lavel, Sainte-Foy, Quebec (Canada)); Coulombe, S. (CANMET, Varennes, Quebec (Canada))

1991-09-01

327

Extraction of phenols from lignin microwave-pyrolysis oil using a switchable hydrophilicity solvent.  

PubMed

Microwave pyrolysis of lignin, an aromatic polymer byproduct from paper-pulping industry, produces char, gases, and lignin pyrolysis oil. Within the oil are valuable phenolic compounds such as phenol, guaiacol and catechol. In this work, we describe a method using switchable hydrophilicity solvents (SHS) to extract phenols as a mixture from lignin microwave-pyrolysis oil at the scale of 10 g of bio-oil. Even at this small scale, losses are small; 96% of the bio-oil was recovered in its three fractions, 72% of guaiacol and 70% of 4-methylguaiacol, the most abundant phenols in the bio-oil, were extracted and 91% of the solvent SHS was recovered after extraction. The starting material (lignin microwave-pyrolysis oil) and the three fractions resulted from SHS extraction were characterized by GC-MS and quantitative (13)C{(1)H} and (31)P{(1)H} NMR spectroscopy. PMID:24384316

Fu, Dongbao; Farag, Sherif; Chaouki, Jamal; Jessop, Philip G

2014-02-01

328

Nicotine Nasal Spray  

MedlinePLUS

... Nicotine nasal spray is in a class of medications called smoking cessation aids. It works by providing nicotine to your body to decrease the withdrawal symptoms experienced when smoking is stopped ...

329

Metal atomization spray nozzle  

DOEpatents

A spray nozzle for a magnetohydrodynamic atomization apparatus has a feed passage for molten metal and a pair of spray electrodes mounted in the feed passage. The electrodes, diverging surfaces which define a nozzle throat and diverge at an acute angle from the throat. Current passes through molten metal when fed through the throat which creates the Lorentz force necessary to provide atomization of the molten metal.

Huxford, Theodore J. (Harriman, TN)

1993-01-01

330

Surface and Spray Aeration  

Microsoft Academic Search

\\u000a urface aeration involves the use of special floating aerators or spray aerators for removing taste\\/odor-causing substances,\\u000a carbon dioxide, hydrogen sulfide, methane, volatile organic compounds, etc. from water, and for oxidizing iron and manganese\\u000a in drinking water. The topics covered in this chapter are: gas solubility, diffusion, equilibrium, mixing, gas transfer, reaeration,\\u000a instream aeration, surface aeration, spray aeration, and engineering design.

Jerry R. Taricska; J. Paul Chen; Yung-Tse Hung; Lawrence K. Wang; Shuai-Wen Zou

331

Motion planning for robotic spray cleaning with environmentally safe solvents  

SciTech Connect

Automatic motion planning of a spray cleaning robot with collision avoidance is presented in this paper. In manufacturing environments, electronic and mechanical components are traditionally cleaned by spraying or dipping them using chlorofluorocarbon (CFC) solvents. As new scientific data show that such solvents are major causes for stratospheric ozone depletion, an alternate cleaning method is needed. Part cleaning with aqueous solvents is environmentally safe, but can require precision spraying at high pressures for extended time periods. Operator fatigue during manual spraying can decrease the quality of the cleaning process. By spraying with a robotic manipulator, the necessary spray accuracy and consistency to manufacture highreliability components can be obtained. Our motion planner was developed to automatically generate motions for spraying robots based on the part geometry and cleaning process parameters. For spraying paint and other coatings a geometric description of the parts and robot may be sufficient for motion planning, since coatings are usually done over the visible surfaces. For spray cleaning, the requirement to reach hidden surfaces necessitates the addition of a rule-based method to the geometric motion planning.

Hwang, Yong K.; Meirans, L.; Drotning, W.D.

1993-09-01

332

Pyrolysis and gasification kinetics of Jordanian oil-shales  

Microsoft Academic Search

Two Jordanian oil-shale samples have been pyrolysed and gasified, non-isothermally, using a thermogravimetric analyser. The controlling parameters studied were the final temperature and influence of particle size as well as the heating rate employed during the process of thermal degradation of the oil-shale sample. The integral method was used in the analysis of weight-loss data to determine the pyrolysis and

J. O. Jaber; S. D. Probert

1999-01-01

333

Non-Isothermal Pyrolysis and Kinetics of Oil Shales  

Microsoft Academic Search

In this research, non-isothermal pyrolysis behavior and kinetics of three oil shales were studied by thermal analysis methods.\\u000a All the thermal effects were endothermic and no exothermic region was observed in DSC curves. When oil shales are heated in\\u000a nitrogen atmosphere in TG\\/DTG, two different mechanisms causing loss of mass were observed. The region between ambient temperature\\u000a and 500 K

M. V. Kök; M. R. Pamir

1999-01-01

334

Pyrolysis of coal  

DOEpatents

A method for mild gasification of crushed coal in a single vertical elongated reaction vessel providing a fluidized bed reaction zone, a freeboard reaction zone, and an entrained reaction zone within the single vessel. Feed coal and gas may be fed separately to each of these reaction zones to provide different reaction temperatures and conditions in each reaction zone. The reactor and process of this invention provides for the complete utilization of a coal supply for gasification including utilization of caking and non-caking or agglomerating feeds in the same reactor. The products may be adjusted to provide significantly greater product economic value, especially with respect to desired production of char having high surface area.

Babu, Suresh P. (Willow Springs, IL); Bair, Wilford G. (Morton Grove, IL)

1992-01-01

335

Waste tire recycling by pyrolysis  

SciTech Connect

This project examines the City of New Orleans' waste tire problem. Louisiana State law, as of January 1, 1991, prohibits the knowing disposal of whole waste tires in landfills. Presently, the numerous waste tire stockpiles in New Orleans range in size from tens to hundreds of tires. New Orleans' waste tire problem will continue to increase until legal disposal facilities are made accessible and a waste tire tracking and regulatory system with enforcement provisions is in place. Tires purchased outside of the city of New Orleans may be discarded within the city's limits; therefore, as a practical matter this study analyzes the impact stemming from the entire New Orleans metropolitan area. Pyrolysis mass recovery (PMR), a tire reclamation process which produces gas, oil, carbon black and steel, is the primary focus of this report. The technical, legal and environmental aspects of various alternative technologies are examined. The feasibility of locating a hypothetical PMR operation within the city of New Orleans is analyzed based on the current economic, regulatory, and environmental climate in Louisiana. A thorough analysis of active, abandoned, and proposed Pyrolysis operations (both national and international) was conducted as part of this project. Siting a PMR plant in New Orleans at the present time is technically feasible and could solve the city's waste tire problem. Pending state legislation could improve the city's ability to guarantee a long term supply of waste tires to any large scale tire reclamation or recycling operation, but the local market for PMR end products is undefined.

Not Available

1992-10-01

336

Flash flow pyrolysis: mimicking flash vacuum pyrolysis in a high-temperature/high-pressure liquid-phase microreactor environment.  

PubMed

Flash vacuum pyrolysis (FVP) is a gas-phase continuous-flow technique where a substrate is sublimed through a hot quartz tube under high vacuum at temperatures of 400-1100 °C. Thermal activation occurs mainly by molecule-wall collisions with contact times in the region of milliseconds. As a preparative method, FVP is used mainly to induce intramolecular high-temperature transformations leading to products that cannot easily be obtained by other methods. It is demonstrated herein that liquid-phase high-temperature/high-pressure (high-T/p) microreactor conditions (160-350 °C, 90-180 bar) employing near- or supercritical fluids as reaction media can mimic the results obtained using preparative gas-phase FVP protocols. The high-T/p liquid-phase "flash flow pyrolysis" (FFP) technique was applied to the thermolysis of Meldrum's acid derivatives, pyrrole-2,3-diones, and pyrrole-2-carboxylic esters, producing the expected target heterocycles in high yields with residence times between 10 s and 10 min. The exact control over flow rate (and thus residence time) using the liquid-phase FFP method allows a tuning of reaction selectivities not easily achievable using FVP. Since the solution-phase FFP method does not require the substrate to be volatile any more--a major limitation in classical FVP--the transformations become readily scalable, allowing higher productivities and space-time yields compared with gas-phase protocols. Differential scanning calorimetry measurements and extensive DFT calculations provided essential information on pyrolysis energy barriers and the involved reaction mechanisms. A correlation between computed activation energies and experimental gas-phase FVP (molecule-wall collisions) and liquid-phase FFP (molecule-molecule collisions) pyrolysis temperatures was derived. PMID:22321044

Cantillo, David; Sheibani, Hassan; Kappe, C Oliver

2012-03-01

337

Validation of salt spray corrosion test  

Microsoft Academic Search

Quality control of corrosion test results implies the validation of the corrosion test method and estimation of the uncertainty of corrosion rate measurement. The corrosion test in an artificial atmosphere of the salt spray mist needs evaluation of corrosivity of the test cabinet by reference specimens. Such calibration of corrosion environment raises very strict requirements for the method description and

Eugenija Ramoškien?; Mykolas Gladkovas; Mudis Šalkauskas

2003-01-01

338

Measurements in liquid fuel sprays  

NASA Technical Reports Server (NTRS)

Techniques for studying the events directly preceding combustion in the liquid fuel sprays are being used to provide information as a function of space and time on droplet size, shape, number density, position, angle of flight and velocity. Spray chambers were designed and constructed for: (1) air-assist liquid fuel research sprays; (2) high pressure and temperature chamber for pulsed diesel fuel sprays; and (3) coal-water slurry sprays. Recent results utilizing photography, cinematography, and calibration of the Malvern particle sizer are reported. Systems for simultaneous measurement of velocity and particle size distributions using laser Doppler anemometry interferometry and the application of holography in liquid fuel sprays are being calibrated.

Chigier, N.

1984-01-01

339

Transportation fuels from biomass via fast pyrolysis and hydroprocessing  

SciTech Connect

Biomass is a renewable source of carbon, which could provide a means to reduce the greenhouse gas impact from fossil fuels in the transportation sector. Biomass is the only renewable source of liquid fuels, which could displace petroleum-derived products. Fast pyrolysis is a method of direct thermochemical conversion (non-bioconversion) of biomass to a liquid product. Although the direct conversion product, called bio-oil, is liquid; it is not compatible with the fuel handling systems currently used for transportation. Upgrading the product via catalytic processing with hydrogen gas, hydroprocessing, is a means that has been demonstrated in the laboratory. By this processing the bio-oil can be deoxygenated to hydrocarbons, which can be useful replacements of the hydrocarbon distillates in petroleum. While the fast pyrolysis of biomass is presently commercial, the upgrading of the liquid product by hydroprocessing remains in development, although it is moving out of the laboratory into scaled-up process demonstration systems.

Elliott, Douglas C.

2013-09-21

340

Electrostatic-spray ionization mass spectrometry.  

PubMed

An electrostatic-spray ionization (ESTASI) method has been used for mass spectrometry (MS) analysis of samples deposited in or on an insulating substrate. The ionization is induced by a capacitive coupling between an electrode and the sample. In practice, a metallic electrode is placed close to but not in direct contact with the sample. Upon application of a high voltage pulse to the electrode, an electrostatic charging of the sample occurs leading to a bipolar spray pulse. When the voltage is positive, the bipolar spray pulse consists first of cations and then of anions. This method has been applied to a wide range of geometries to emit ions from samples in a silica capillary, in a disposable pipet tip, in a polymer microchannel, or from samples deposited as droplets on a polymer plate. Fractions from capillary electrophoresis were collected on a polymer plate for ESTASI MS analysis. PMID:22876737

Qiao, Liang; Sartor, Romain; Gasilova, Natalia; Lu, Yu; Tobolkina, Elena; Liu, Baohong; Girault, Hubert H

2012-09-01

341

Preparation, characterisation and optimisation of lithium battery anodes consisting of silicon synthesised using Laser assisted Chemical Vapour Pyrolysis  

NASA Astrophysics Data System (ADS)

Suitability of silicon prepared using Laser assisted Chemical Vapour Pyrolysis (LaCVP) as a potential anode material in lithium batteries is systematically investigated. Its compositional, morphological, physical-chemical and electrochemical properties are compared to a current benchmark commercial silicon. Important differences in particle size and particle composition are found which, as shown, affect critically the rheological properties of the corresponding electrode slurries. In order to overcome the rheological problems of prepared nanosilicon, we introduce and optimise a spraying method instead of using the usual casting technique for slurry application. Interestingly, the optimised electrodes show similar electrochemical performance, regardless of the particle size or composition of nanosilicon. This unexpected result is explained by the unusually high resistance of electrochemical wiring in silicon-based electrodes (about 60 Ohm per 1 mg cm-2 of active material loading). Despite that, the optimised material still shows a capacity up to 1200 mA h g-1 at a relatively high loading of 1.6 mg cm-2 and after 20 cycles. On the other hand, by decreasing the loading to below ca. 0.9 mg cm-2 the wiring problems are effectively overcome and capacities close to theoretical values can be obtained.

Veliscek, Ziga; Perse, Lidija Slemenik; Dominko, Robert; Kelder, Erik; Gaberscek, Miran

2015-01-01

342

Waste tire recycling by pyrolysis  

SciTech Connect

This project examines the City of New Orleans` waste tire problem. Louisiana State law, as of January 1, 1991, prohibits the knowing disposal of whole waste tires in landfills. Presently, the numerous waste tire stockpiles in New Orleans range in size from tens to hundreds of tires. New Orleans` waste tire problem will continue to increase until legal disposal facilities are made accessible and a waste tire tracking and regulatory system with enforcement provisions is in place. Tires purchased outside of the city of New Orleans may be discarded within the city`s limits; therefore, as a practical matter this study analyzes the impact stemming from the entire New Orleans metropolitan area. Pyrolysis mass recovery (PMR), a tire reclamation process which produces gas, oil, carbon black and steel, is the primary focus of this report. The technical, legal and environmental aspects of various alternative technologies are examined. The feasibility of locating a hypothetical PMR operation within the city of New Orleans is analyzed based on the current economic, regulatory, and environmental climate in Louisiana. A thorough analysis of active, abandoned, and proposed Pyrolysis operations (both national and international) was conducted as part of this project. Siting a PMR plant in New Orleans at the present time is technically feasible and could solve the city`s waste tire problem. Pending state legislation could improve the city`s ability to guarantee a long term supply of waste tires to any large scale tire reclamation or recycling operation, but the local market for PMR end products is undefined.

Not Available

1992-10-01

343

Characterisations Of Al{sub 2}O{sub 3}-13% Wt TiO{sub 2} Deposition On Mild Steel Via Plasma Spray Method  

SciTech Connect

To date, plasma sprayed alumina titania have been widely used as wear resistance coatings in textile, machinery and printing industries. Previous studies showed that the coating microstructures and properties were strongly depended on various parameters such as ceramic composition, grain size powders and spray parameters, thus, influencing the melting degree of the alumina titania during the deposition process. The aim of this study focuses on the evolution of the micron sizes of alumina-13%wt titania at different plasma spray power, ranging from 20kW to 40kW. It was noted that the coating porosity of alumina-13%wt titania were decreased from 6.2% to 4% by increasing the plasma power from 20 to 40 kW. At lower power value, partially melted powders were deposited, generating over 6% porosity within the microstructures. Percentage of porosity about 5.6% gave the best ratio of bi-modal structures, providing the highest microhardness value. Furthermore, the effect of microstructure and porosity formation on wear resistance was also discussed. Coatings with less porosity exhibited better resistance to wear, in which the wear resistance of coated mild steel possessed only {approx}5 x 10{sup -4} cm{sup 3}/Nm with 4% of porosity.

Yusoff, N. H.; Isa, M. C. [Maritime Technology Divison, Science And Technology Research Institute For Defence (STRIDE) c/o KD MALAYA 32100 Pangkalan TLDM, Lumut, Perak (Malaysia); Ghazali, M. J.; Muchtar, A.; Forghani, S. [Dept. of Mechanical and Materials Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor (Malaysia); Daud, A. R. [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor (Malaysia)

2011-01-17

344

Spray combustion stability  

NASA Technical Reports Server (NTRS)

The central purpose of this project is the improvement of liquid-fueled rocket motor design technology in order to assist the establishment of economical commercial access to space through the development of engines with enhanced performance and reliability. Specific research effort is focused on spray physics and associated combustion instability phenomena. Results concerning high pressure droplet gasification model, droplet turbulent dispersion model, and spray atomization model will contribute to the development of new computational tools for design of stable liquid propellant rocket engines.

Liang, Pak-Yan; Jeng, San-Mou; Litchford, Ronald

1989-01-01

345

Spray deposition - A summary  

NASA Astrophysics Data System (ADS)

Important findings are presented from six studies concerning the application of the Osprey metal spray-deposition process to (1) Cu-base alloys, (2) Cu-base case-hardening alloys, (3) preform formation, (4) 7075 and 8090 Al alloys, (5) superalloys, and (6) superalloy tubes. It is in the aggregate shown that while the details of the process are materials-specific, there are no technical barriers to scale-up and commercialization. Each of the alloy systems considered can be spray-formed into various near-net-shape products.

Lewis, Richard E.; Lawley, Alan

346

Products from pyrolysis of gas-phase propionaldehyde.  

PubMed

A hyperthermal nozzle was utilized to study the thermal decomposition of propionaldehyde, CH3CH2CHO, over a temperature range of 1073-1600 K. Products were identified with two detection methods: matrix-isolation Fourier transform infrared spectroscopy and photoionization mass spectrometry. Evidence was observed for four reactions during the breakdown of propionaldehyde: ?-C-C bond scission yielding CH3CH2, CO, and H, an elimination reaction forming methylketene and H2, an isomerization pathway leading to propyne via the elimination of H2O, and a ?-C-C bond scission channel forming methyl radical and (•)CH2CHO. The products identified during this experiment were CO, HCO, CH3CH2, CH3CH?C?O, H2O, CH3C?CH, CH3, H2C?C?O, CH2CH2, CH3CH?CH2, HC?CH, CH2CCH, H2CO, C4H2, C4H4, and CH3CHO. The first eight products result from primary or bimolecular reactions involving propionaldehyde while the remaining products occur from reactions including the initial pyrolysis products. While the pyrolysis of propionaldehyde involves reactions similar to those observed for acetaldehyde and butyraldehyde in recent studies, there are a few unique products observed which highlight the need for further study of the pyrolysis mechanism. PMID:25526259

Warner, Brian J; Wright, Emily M; Foreman, Hannah E; Wellman, Courtney D; McCunn, Laura R

2015-01-01

347

Mechanism of fast pyrolysis of lignin: studying model compounds.  

PubMed

Fast pyrolysis of lignin is one of the most promising methods to convert the complex and irregular structure of lignin into renewable chemicals and fuel. During pyrolysis the complex set of radical reactions, rearrangements, and eliminations is influenced by temperature, pressure, and the lignin origin and structure. This model compound study aims to understand reaction pathways and how primary intermediates lead to the observed product selectivity. The pyrolysis microreactor directly connected to the gas chromatograph with a mass spectrometer (py-GC/MS) detects the final products, while imaging photoelectron photoion coincidence (iPEPICO) with VUV synchrotron radiation shows primary decomposition radicals. The tested model compounds, diphenylether (DPE) and ortho-methoxyphenol (guaiacol), represent a common lignin linkage and the most present subunit in lignin, respectively. Radical fragments, such as the hydroxycyclopentadienyl radical in guaiacol decomposition, are identified by mass-selected threshold photoelectron spectra (ms-TPES) in excellent agreement with the Franck-Condon simulation. While homolysis produces phenoxy-, phenyl-, and hydroxyphenoxy radicals, which are observed in high vacuum, radically initiated reactions are dominant in ambient conditions and produce recombination and rearrangement products, such as 2-hydroxybenzaldehyde in the case of guaiacol. The degree of substitution plays a dominant role in both the stabilization of the intermediate radical and the following degree of recombination. The recombination of phenoxy radicals is enhanced compared to hydroxy-phenoxy radicals. PMID:24937704

Custodis, Victoria B F; Hemberger, Patrick; Ma, Zhiqiang; van Bokhoven, Jeroen A

2014-07-24

348

CORROSIVITY AND COMPOSITION OF RAW AND TREATED PYROLYSIS OILS  

SciTech Connect

Fast pyrolysis offers a relatively low cost method of processing biomass to produce a liquid product that has the potential for conversion to several types of liquid fuels. The liquid product of fast pyrolysis, known as pyrolysis oil or bio-oil, contains a high oxygen content primarily in the form of water, carboxylic acids, phenols, ketones and aldehydes. These oils are typically very acidic with a Total Acid Number that is often in the range of 50 to 100, and previous studies have shown this material to be quite corrosive to common structural materials. Removal of at least some of the oxygen and conversion of this oil to a more useful product that is considerably less corrosive can be accomplished through a hydrogenation process. The product of such a treatment is considered to have the potential for blending with crude oil for processing in petroleum refineries. Corrosion studies and chemical analyses have been conducted using as produced bio-oil samples as well as samples that have been subjected to different levels of oxygen removal. Chemical analyses show treatment affected the concentrations of carboxylic acids contained in the oil, and corrosion studies showed a positive benefit of the oxygen removal. Results of these studies will be presented in this paper.

Keiser, Jim; Howell, Michael; Connatser, Raynella M.; Lewis, Sam; Elliott, Douglas C.

2012-10-14

349

Pyrolysis kinetics of algal consortia grown using swine manure wastewater.  

PubMed

In this study, pyrolysis kinetics of periphytic microalgae consortia grown using swine manure slurry in two seasonal climatic patterns in northwest Arkansas were investigated. Four heating rates (5, 10, 20 and 40 °C min(-1)) were used to determine the pyrolysis kinetics. Differences in proximate, ultimate, and heating value analyses reflected variability in growing substrate conditions, i.e., flocculant use, manure slurry dilution, and differences in diurnal solar radiation and air temperature regimes. Peak decomposition temperature in algal harvests varied with changing the heating rate. Analyzing pyrolysis kinetics using differential and integral isoconversional methods (Friedman, Flynn-Wall-Ozawa, and Kissinger-Akahira-Sunose) showed strong dependency of apparent activation energy on the degree of conversion suggesting parallel reaction scheme. Consequently, the weight loss data in each thermogravimetric test was modeled using independent parallel reactions (IPR). The quality of fit (QOF) for the model ranged between 2.09% and 3.31% indicating a good agreement with the experimental data. PMID:25105272

Sharara, Mahmoud A; Holeman, Nathan; Sadaka, Sammy S; Costello, Thomas A

2014-10-01

350

Production of bran castor biochar through slow pyrolysis  

NASA Astrophysics Data System (ADS)

Pyrolysis is a thermal process of great importance in the present context, since it constitutes a significant alternative to adequate use of organic waste. The principal products obtained in the pyrolysis of discarded biomass are bio-oil, biogas and biochar. Biochar, in turn, may play a relevant role when applied to the soil to sequester carbon and as a soil conditioner, a material comparable to organic matter of Indians Black Earths from the Amazon Region [1]. Seeking to determine the best methods of preparation of biochar, we studied the pyrolysis of bran castor residue of the Brazilian biodiesel industry. Eight samples, from FM1 to FM8, were prepared in a factorial design 23 using two temperature (300 and 350 °C), two heating velocity (5 and 10 °C min-1) and two period of heating (30 and 60 min). The eight samples were studied using the spectroscopy: EPR, FTIR, RMN, XPS, and elemental analysis. By elemental analysis, the samples that keep for lower temperature of pyrolysis, 300 °C, showed H/C and N/C ratios greater than the samples of 350 °C. That higher value can be attributed to chemical structure more aliphatic than aromatic mainly in the FM7 sample (V = 10 °C min-1, T = 300 °C, P = 30 min). The greater N/C ratio correlated with a superior amount of nitrogenous functions, presenting by both FM7 and FM4 samples, as determined by 13C NMR spectroscopy with absorptions in 175 ppm (amide) and 55 ppm (N-alkyl).

Pissinati de Rezende, E. I.; Mangrich, A. S.; Batista, M. G. F.; Toledo, J. M. S.; Novotny, E. H.

2012-04-01

351

Programable Plasma-Spray System  

NASA Technical Reports Server (NTRS)

NASA-funded research led to development of automated plasma-spray system programable and reproducible. System utilizes standard plasma-spray equipment with noncoherent light-measuring system and microprocessor. System monitors and controls surface contours and coating thickness. Other advantages of system are consistant coating reproducibility, exact blending and feathering operations, ability to handle complex shapes and ease of changing spray parameters.

Fetheroff, C. W.; Derkacs, T.; Matay, I. M.; Toth, I.

1982-01-01

352

Pyrolysis of waste tyres: A review  

SciTech Connect

Graphical abstract: - Highlights: • Pyrolysis of waste tyres produces oil, gas and char, and recovered steel. • Batch, screw kiln, rotary kiln, vacuum and fluidised-bed are main reactor types. • Product yields are influenced by reactor type, temperature and heating rate. • Pyrolysis oils are complex and can be used as chemical feedstock or fuel. • Research into higher value products from the tyre pyrolysis process is reviewed. - Abstract: Approximately 1.5 billion tyres are produced each year which will eventually enter the waste stream representing a major potential waste and environmental problem. However, there is growing interest in pyrolysis as a technology to treat tyres to produce valuable oil, char and gas products. The most common reactors used are fixed-bed (batch), screw kiln, rotary kiln, vacuum and fluidised-bed. The key influence on the product yield, and gas and oil composition, is the type of reactor used which in turn determines the temperature and heating rate. Tyre pyrolysis oil is chemically very complex containing aliphatic, aromatic, hetero-atom and polar fractions. The fuel characteristics of the tyre oil shows that it is similar to a gas oil or light fuel oil and has been successfully combusted in test furnaces and engines. The main gases produced from the pyrolysis of waste tyres are H{sub 2}, C{sub 1}–C{sub 4} hydrocarbons, CO{sub 2}, CO and H{sub 2}S. Upgrading tyre pyrolysis products to high value products has concentrated on char upgrading to higher quality carbon black and to activated carbon. The use of catalysts to upgrade the oil to a aromatic-rich chemical feedstock or the production of hydrogen from waste tyres has also been reported. Examples of commercial and semi-commercial scale tyre pyrolysis systems show that small scale batch reactors and continuous rotary kiln reactors have been developed to commercial scale.

Williams, Paul T., E-mail: p.t.williams@leeds.ac.uk

2013-08-15

353

Pyrolysis Analysis and Kinetics of Crude Oils  

Microsoft Academic Search

This research presents the results of an experimental study on the determination of pyrolysis behaviour and kinetics of six\\u000a crude oils by differential scanning calorimetry (DSC) and thermogravimetry (TG\\/DTG). Crude oil pyrolysis indicated two main\\u000a temperature ranges where loss of mass was observed. The first region between ambient to 400°C was distillation. The second\\u000a region between 400 and 600°C was

M. V. Kök; O. Karacan

1998-01-01

354

Current problems in plasma spray processing  

SciTech Connect

This detailed report summarizes 8 contributions from a thermal spray conference that was held in late 1991 at Brookhaven National Laboratory (Upton, Long Island, NY, USA). The subject of ``Plasma Spray Processing`` is presented under subject headings of Plasma-particle interactions, Deposit formation dynamics, Thermal properties of thermal barrier coatings, Mechanical properties of coatings, Feed stock materials, Porosity: An integrated approach, Manufacture of intermetallic coatings, and Synchrotron x-ray microtomographic methods for thermal spray materials. Each section is intended to present a concise statement of a specific practical and/or scientific problem, then describe current work that is being performed to investigate this area, and finally to suggest areas of research that may be fertile for future activity.

Berndt, C.C.; Brindley, W.; Goland, A.N.; Herman, H.; Houck, D.L.; Jones, K.; Miller, R.A.; Neiser, R.; Riggs, W.; Sampath, S.; Smith, M.; Spanne, P. [State Univ. of New York, Stony Brook, NY (United States). Thermal Spray Lab.

1991-12-31

355

Current problems in plasma spray processing  

SciTech Connect

This detailed report summarizes 8 contributions from a thermal spray conference that was held in late 1991 at Brookhaven National Laboratory (Upton, Long Island, NY, USA). The subject of Plasma Spray Processing'' is presented under subject headings of Plasma-particle interactions, Deposit formation dynamics, Thermal properties of thermal barrier coatings, Mechanical properties of coatings, Feed stock materials, Porosity: An integrated approach, Manufacture of intermetallic coatings, and Synchrotron x-ray microtomographic methods for thermal spray materials. Each section is intended to present a concise statement of a specific practical and/or scientific problem, then describe current work that is being performed to investigate this area, and finally to suggest areas of research that may be fertile for future activity.

Berndt, C.C.; Brindley, W.; Goland, A.N.; Herman, H.; Houck, D.L.; Jones, K.; Miller, R.A.; Neiser, R.; Riggs, W.; Sampath, S.; Smith, M.; Spanne, P. (State Univ. of New York, Stony Brook, NY (United States). Thermal Spray Lab.)

1991-01-01

356

Decaking of coal or oil shale during pyrolysis in the presence of iron oxides  

DOEpatents

A method for producing a fuel from the pyrolysis of coal or oil shale in the presence of iron oxide in an inert gas atmosphere is described. The method includes the steps of pulverizing feed coal or oil shale, pulverizing iron oxide, mixing the pulverized feed and iron oxide, and heating the mixture in a gas atmosphere which is substantially inert to the mixture so as to form a product fuel, which may be gaseous, liquid and/or solid. The method of the invention reduces the swelling of coals, such as bituminous coal and the like, which are otherwise known to swell during pyrolysis. 4 figs., 8 tabs.

Rashid Khan, M.

1988-05-05

357

Analysis of photographic records of coal pyrolysis  

SciTech Connect

Bituminous coals upon heating undergo melting and pyrolytic decomposition with significant parts of the coal forming an unstable liquid that can escape from the coal by evaporation. The transient liquid within the pyrolyzing coal causes softening or plastic behavior that can influence the chemistry and physics of the process. Bubbles of volatiles can swell the softened coal mass in turn affecting the combustion behavior of the coal particles. The swelling behavior of individual coal particles has to be taken into account both as the layout as well as for the operation of pyrolysis, coking and performance of coal-fired boilers. Increased heating rates generally increase the amount of swelling although it is also known that in some cases, even highly swelling coals can be transformed into char with no swelling if they are heated slowly enough. The swelling characteristics of individual coal particles have been investigated by a number of workers employing various heating systems ranging from drop tube and shock tube furnaces, flow rate reactors and electrical heating coils. Different methods have also been employed to determine the swelling factors. The following sections summarize some of the published literature on the subject and outline the direction in which the method of analysis will be further extended in the study of the swelling characteristics of hvA bituminous coal particles that have been pyrolyzed with a laser beam.

Dodoo, J.N.D.

1991-10-01

358

Ocean Spray Lubricates Winds  

ERIC Educational Resources Information Center

According to a new study by two University of California, Berkeley, mathematicians and their Russian colleague, the water droplets kicked up by rough seas serve to lubricate the swirling winds of hurricanes and cyclones, letting them build to speeds approaching 200 miles per hour. Without the lubricating effect of the spray, the mathematicians…

Journal of College Science Teaching, 2005

2005-01-01

359

Invisible fingerprints Spray bottle  

E-print Network

Invisible fingerprints Procedure Materials Ninhydrin Methanol Spray bottle Index card Hairdryer with an index card that has several well placed fingerprints. Pass this card around the room at the beginning the next. The idea of using fingerprints as a unique identifying feature was accepted in the United States

Weston, Ken

360

Titanium Cold Spray Coatings  

NASA Astrophysics Data System (ADS)

Titanium Cold Spray Coatings Cold Spray is an emerging technology used for the deposition of coatings for many industries including aerospace. This technique allows the deposition of metallic materials at low temper-atures below their melting point. The aim of this research was to develop a test technique that can measure the degree to which a cold spray coating achieves mechanical properties similar to a traditional bulk material. Vickers hardness testing and nanoindentation were used as micro-and nano-scale measurement techniques to characterize the mechanical properties of titanium coatings, deposited at different deposition conditions, and bulk Ti. The mechanical properties of bulk titanium and titanium coatings were measured over a range of length scales, with the indentation size effect examined with Meyer's law. Hardness measurements are shown to be affected by material porosity, microstructure and coating particle bonding mechanism. Hard-ness measurements showed that Ti coatings deposited at higher gas pressures and temperatures demonstrate an indentation load response similar to bulk Ti. Key words: titanium, cold spray, Vickers hardness, nanoindentation, indentation size effect, microstructure, mechanical properties

Ajaja, Jihane; Goldbaum, Dina; Chromik, Richard; Yue, Stephen; Rezaeian, Ahmad; Wong, Wilson; Irissou, Eric; Legoux, Jean-Gabriel

361

Comparative assessment of municipal sewage sludge incineration, gasification and pyrolysis for a sustainable sludge-to-energy management in Greece  

SciTech Connect

Highlights: • The high output of MSS highlights the need for alternative routes of valorization. • Evaluation of 3 sludge-to-energy valorisation methods through SWOT analysis. • Pyrolysis is an energy and material recovery process resulting to ‘zero waste’. • Identification of challenges and barriers for MSS pyrolysis in Greece was investigated. • Adopters of pyrolysis systems face the challenge of finding new product markets. - Abstract: For a sustainable municipal sewage sludge management, not only the available technology, but also other parameters, such as policy regulations and socio-economic issues should be taken in account. In this study, the current status of both European and Greek Legislation on waste management, with a special insight in municipal sewage sludge, is presented. A SWOT analysis was further developed for comparison of pyrolysis with incineration and gasification and results are presented. Pyrolysis seems to be the optimal thermochemical treatment option compared to incineration and gasification. Sewage sludge pyrolysis is favorable for energy savings, material recovery and high added materials production, providing a ‘zero waste’ solution. Finally, identification of challenges and barriers for sewage sludge pyrolysis deployment in Greece was investigated.

Samolada, M.C. [Dept. Secretariat of Environmental and Urban Planning – Decentralized Area Macedonian Thrace, Taki Oikonomidi 1, 54008 Thessaloniki (Greece); Zabaniotou, A.A., E-mail: azampani@auth.gr [Aristotle University of Thessaloniki, Dept. of Chemical Engineering, University Box 455, University Campus, 541 24 Thessaloniki (Greece)

2014-02-15

362

Trap and recombination centers study in sprayed Cu2ZnSnS4 thin films  

NASA Astrophysics Data System (ADS)

In this work, a study of trap and recombination center properties in polycrystalline Cu2ZnSnS4 thin films is carried out in order to understand the poor performance in Cu2ZnSnS4 thin film solar cells. Thermally stimulated current has been studied in Cu2ZnSnS4 deposited by pneumatic spray pyrolysis method using various heating rates, in order to gain information about trap centers and/or deep levels present within the band-gap of this material. A set of temperature-dependent current curves revealed three levels with activation energy of 126 ± 10, 476 ± 25, and 1100 ± 100 meV. The possible nature of the three levels found is presented, in which the first one is likely to be related to CuZn antisites, while second and third to Sn vacancies and SnCu antisites, respectively. The values of frequency factor, capture cross section, and trap concentration have been determined for each center.

Courel, Maykel; Vigil-Galán, O.; Jiménez-Olarte, D.; Espíndola-Rodríguez, M.; Saucedo, E.

2014-10-01

363

Effect of Indium Doping on the Properties of Sprayed Cd0.8 Zn0.2S Films  

NASA Astrophysics Data System (ADS)

Indium doped mixed sulphide films were prepared by the spray pyrolysis technique on glass substrates by spraying aqueous solutions of Cadmium chloride, Zinc Chloride, Indium Trichloride and Thiourea. The Indium doping concentration was varied from 0.025% to 2.00% by weight. It is found that the film thickness increases with increase in doping concentration. The electrical and optical properties of the films such as dark conductivity thermoelectric power and optical absorption were studied. The films prepared with 1% by weight doping concentration show high thermoelectric power and dark conductivity.

Uplane, M. D.; Lokhande, C. D.; Patil, P. S.; Bhosale, C. H.

1996-10-01

364

Improved Orifice Plate for Spray Gun  

NASA Technical Reports Server (NTRS)

Erratic spray pattern of commercial spray gun changed to repeatable one by simple redesign of two parts. In modified spray gun orifice plate and polytetrafluoroethylene bushing redesigned to assure centering and alignment with nozzle. Such improvement useful in many industrial applications requiring repeatable spray patterns. Might include spraying of foam insulation, paint, other protective coatings, detergents, abrasives, adhesives, process chemicals, or fuels. Unmodified spray gun produces erratic spray because lateral misalignment between orifice plate and nozzle.

Cunningham, W.

1986-01-01

365

Simulation of a turbulent spray flame using coupled PDF gas phase and spray flamelet modeling  

SciTech Connect

A joint mixture fraction-enthalpy probability density function (PDF) is proposed for the simulation of turbulent spray flames. The PDF transport equation is deduced and modeled. The interaction-by-exchange-with-the-mean (IEM) model that has been developed for gas-phase flows is extended to describe molecular mixing in nonreactive and reactive spray flows. The joint PDF transport equation is solved by a hybrid finite-volume and Lagrangian Monte Carlo method. Standard spray and turbulence models are used to describe the gas phase and the liquid phase. A turbulent methanol/air spray flame is simulated using the present method. Detailed chemistry is implemented through the spray flamelet model. The precalculated spray flamelet library for methanol/air combustion comprises 23 species and 168 elementary reactions. Thus, the model is capable of predicting the formation of radicals and of pollutants. Different values for the model constant C{sub {phi}} in the IEM model are tested. The numerical results for the gas velocity, the gas temperature, and the mass fraction of methanol vapor are compared with experimental data in the literature. Good agreement with experiment is obtained when C{sub {phi}}=2.0. Marginal PDFs of mixture fraction, enthalpy, and gas temperature are presented. The computed PDFs of mixture fraction are compared with the presumed standard {beta} function and modified {beta} function. The results show that the standard {beta} function fails to reproduce bimodal shapes observed in transported PDF computation, while the modified {beta} function, fits the computed PDFs very well. Moreover, joint PDFs of mixture fraction and enthalpy are presented and analyzed. The enthalpy and mixture fraction are strongly correlated. The samples that deviate from the linear correlation are due to the energy consumption of local spray evaporation. (author)

Ge, Hai-Wen [Engine Research Center, University of Wisconsin-Madison, 1500 Engineering Drive, Madison, WI 53706 (United States); Gutheil, Eva [Interdisziplinaeres Zentrum fuer Wissenschaftliches Rechnen, Universitaet Heidelberg, Im Neuenheimer Feld 368, 69120 Heidelberg (Germany)

2008-04-15

366

The study on the interdependence of spray characteristics and evaporation history of fuel spray in high temperature air crossflow  

NASA Astrophysics Data System (ADS)

A numerical calculation method is used to predict the variation of the characteristics of fuel spray moving in a high temperature air crossflow, mainly, Sauter mean diameter SMD, droplet size distribution index N of Rosin-Rammler distribution and evaporation percentage changing with downstream distance X from the nozzle. The effect of droplet heat-up period evaporation process and forced convection are taken into full account; thus, the calculation model is a very good approximation to the process of spray evaporation in a practical combustor, such as ramjet, aero-gas turbine, liquid propellant rocket, diesel and other liquid fuel-powered combustion devices. The changes of spray characteristics N, SMD and spray evaporation percentage with air velocity, pressure, temperature, fuel injection velocity, and the initial spray parameters are presented.

Zhu, J. Y.; Chin, J. S.

1986-06-01

367

Catalytic fast pyrolysis of lignocellulosic biomass  

SciTech Connect

Increasing energy demand, especially in the transportation sector, and soaring CO2 emissions necessitate the exploitation of renewable sources of energy. Despite the large variety of new energy Q3 carriers, liquid hydrocarbon still appears to be the most attractive and feasible form of transportation fuel taking into account the energy density, stability and existing infrastructure. Biomass is an abundant, renewable source of energy; however, utilizing it in a cost-effective way is still a substantial challenge. Lignocellulose is composed of three major biopolymers, namely cellulose, hemicellulose and lignin. Fast pyrolysis of biomass is recognized as an efficient and feasible process to selectively convert lignocellulose into a liquid fuel—bio-oil. However bio-oil from fast pyrolysis contains a large amount of oxygen, distributed in hundreds of oxygenates. These oxygenates are the cause of many negative properties, such as low heating values, high corrosiveness, high viscosity, and instability; they also greatly Q4 limit the application of bio-oil particularly as transportation fuel. Hydrocarbons derived from biomass are most attractive because of their high energy density and compatibility with the existing infrastructure. Thus, converting lignocellulose into transportation fuels via catalytic fast pyrolysis has attracted much attention. Many studies related to catalytic fast pyrolysis of biomass have been published. The main challenge of this process is the development of active and stable catalysts that can deal with a large variety of decomposition intermediates from lignocellulose. This review starts with the current understanding of the chemistry in fast pyrolysis of lignocellulose and focuses on the development of catalysts in catalytic fast pyrolysis. Recent progress in the experimental studies on catalytic fast pyrolysis of biomass is also summarized with the emphasis on bio-oil yields and quality.

Liu, Changjun; Wang, Huamin; Karim, Ayman M.; Sun, Junming; Wang, Yong

2014-11-21

368

Laser pyrolysis fabrication of ferromagnetic gamma'-Fe4N and FeC nanoparticles  

NASA Technical Reports Server (NTRS)

Using the laser pyrolysis method, single phase gamma'-Fe4N nanoparticles were prepared by a two step method involving preparation of nanoscale iron oxide and a subsequent gas-solid nitridation reaction. Single phase Fe3C and Fe7C3 could be prepared by laser pyrolysis from Fe(CO)5 and 3C2H4 directly. Characterization techniques such as XRD, TEM and vibrating sample magnetometer were used to measure phase structure, particle size and magnetic properties of these nanoscale nitride and carbide particles. c2000 American Journal of Physics.

Grimes, C. A.; Qian, D.; Dickey, E. C.; Allen, J. L.; Eklund, P. C.

2000-01-01

369

Well-to-wheels analysis of fast pyrolysis pathways with the GREET model.  

SciTech Connect

The pyrolysis of biomass can help produce liquid transportation fuels with properties similar to those of petroleum gasoline and diesel fuel. Argonne National Laboratory conducted a life-cycle (i.e., well-to-wheels [WTW]) analysis of various pyrolysis pathways by expanding and employing the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. The WTW energy use and greenhouse gas (GHG) emissions from the pyrolysis pathways were compared with those from the baseline petroleum gasoline and diesel pathways. Various pyrolysis pathway scenarios with a wide variety of possible hydrogen sources, liquid fuel yields, and co-product application and treatment methods were considered. At one extreme, when hydrogen is produced from natural gas and when bio-char is used for process energy needs, the pyrolysis-based liquid fuel yield is high (32% of the dry mass of biomass input). The reductions in WTW fossil energy use and GHG emissions relative to those that occur when baseline petroleum fuels are used, however, is modest, at 50% and 51%, respectively, on a per unit of fuel energy basis. At the other extreme, when hydrogen is produced internally via reforming of pyrolysis oil and when bio-char is sequestered in soil applications, the pyrolysis-based liquid fuel yield is low (15% of the dry mass of biomass input), but the reductions in WTW fossil energy use and GHG emissions are large, at 79% and 96%, respectively, relative to those that occur when baseline petroleum fuels are used. The petroleum energy use in all scenarios was restricted to biomass collection and transportation activities, which resulted in a reduction in WTW petroleum energy use of 92-95% relative to that found when baseline petroleum fuels are used. Internal hydrogen production (i.e., via reforming of pyrolysis oil) significantly reduces fossil fuel use and GHG emissions because the hydrogen from fuel gas or pyrolysis oil (renewable sources) displaces that from fossil fuel natural gas and the amount of fossil natural gas used for hydrogen production is reduced; however, internal hydrogen production also reduces the potential petroleum energy savings (per unit of biomass input basis) because the fuel yield declines dramatically. Typically, a process that has a greater liquid fuel yield results in larger petroleum savings per unit of biomass input but a smaller reduction in life-cycle GHG emissions. Sequestration of the large amount of bio-char co-product (e.g., in soil applications) provides a significant carbon dioxide credit, while electricity generation from bio-char combustion provides a large energy credit. The WTW energy and GHG emissions benefits observed when a pyrolysis oil refinery was integrated with a pyrolysis reactor were small when compared with those that occur when pyrolysis oil is distributed to a distant refinery, since the activities associated with transporting the oil between the pyrolysis reactors and refineries have a smaller energy and emissions footprint than do other activities in the pyrolysis pathway.

Han, J.; Elgowainy, A.; Palou-Rivera, I.; Dunn, J.B.; Wang, M.Q. (Energy Systems)

2011-12-01

370

The role of growth parameters on structural, morphology and optical properties of sprayed ZnS thin films  

Microsoft Academic Search

ZnS thin films were prepared by spray pyrolysis technique using aqueous of zinc chloride and thiourea at molar ratio of 1:1,\\u000a 1:2, and 2:1. The depositions were carried out on substrates heated from 400 to 520 C The films were then annealed under\\u000a sulphur atmosphere for 90 min at 450 and 550 C. The crystallites exhibit preferential orientation along the [002]? or [111]?

Mustafa Özta?; Metin Bedir; ?ule Ocak; R. Güler Y?ld?r?m

2007-01-01

371

9 CFR 590.542 - Spray process drying operations.  

Code of Federal Regulations, 2014 CFR

...cleaning methods or dismantled and cleaned after use or as necessary when operations have been interrupted. (1) Spray nozzles, orifices, cores, or whizzers shall be cleaned immediately after cessation of drying operations. (2) Equipment shall be...

2014-01-01

372

9 CFR 590.542 - Spray process drying operations.  

Code of Federal Regulations, 2012 CFR

...cleaning methods or dismantled and cleaned after use or as necessary when operations have been interrupted. (1) Spray nozzles, orifices, cores, or whizzers shall be cleaned immediately after cessation of drying operations. (2) Equipment shall be...

2012-01-01

373

9 CFR 590.542 - Spray process drying operations.  

Code of Federal Regulations, 2013 CFR

...cleaning methods or dismantled and cleaned after use or as necessary when operations have been interrupted. (1) Spray nozzles, orifices, cores, or whizzers shall be cleaned immediately after cessation of drying operations. (2) Equipment shall be...

2013-01-01

374

Theory vs. Practice in Direct Evaporative Roof Spray Cooling  

E-print Network

This paper will examine in depth the development of roof spray cooling in this country and elsewhere, the theory and practice of roof cooling, and the limits of system application. While this relatively simple method of air conditioning has been...

Smith, J. L.; Smith, J. C.

1985-01-01

375

Structural, morphological, optical and compositional characterization of spray deposited Ga doped ZnO thin film for Dye-Sensitized Solar Cell application  

NASA Astrophysics Data System (ADS)

Zinc Oxide and Gallium doped Zinc Oxide films have been deposited by the Spray Pyrolysis method onto preheated glass substrates using Zinc acetate and Gallium (III) acetyl acetonate as precursors for Zn and Ga ions, respectively. The effect of ZnO and Ga doping on the structural, morphological, optical and chemical properties of sprayed ZnO and Gallium doped ZnO thin films were investigated. XRD studies reveal that the films are crystalline with hexagonal (wurtzite) crystal structure. The average transparency in the visible range was around 75% for the thin film deposited using Gallium doping. X-ray Photoelectron Spectroscopy (XPS) was utilized to view the changes in the oxidation state of ZnO and Gallium doped ZnO thin films. The ZnO and Gallium doped ZnO thin film has been deposited above the Indium Tin Oxide (ITO) coated glass substrate. The efficiency of the obtained DSSC measured for 0.1 M ZnO thin film by sensitizing for 12 h was, ? = 2.5%. Similarly for Gallium doped Zinc Oxide, the efficiency ? is found to be 3.9%, 4.1% and 4.3% for every increase in doping of Gallium concentrations which is utilized for the application of Dye-Sensitized Solar Cell.

Amala Rani, A.; Ernest, Suhashini

2014-11-01

376

The effect of the film thickness and doping content of SnO2:F thin films prepared by the ultrasonic spray method  

NASA Astrophysics Data System (ADS)

This paper reports on the effects of film thickness and doping content on the optical and electrical properties of fluorine-doped tin oxide. Tin (II) chloride dehydrate, ammonium fluoride dehydrate, ethanol and HCl were used as the starting materials, dopant source, solvent and stabilizer, respectively. The doped films were deposited on a glass substrate at different concentrations varying between 0 and 5 wt% using an ultrasonic spray technique. The SnO2:F thin films were deposited at a 350 °C pending time (5, 15, 60 and 90 s). The average transmission was about 80%, and the films were thus transparent in the visible region. The optical energy gap of the doped films with 2.5 wt% F was found to increase from 3.47 to 3.89 eV with increasing film thickness, and increased after doping at 5 wt%. The decrease in the Urbach energy of the SnO2:F thin films indicated a decrease in the defects. The increase in the electrical conductivity of the films reached maximum values of 278.9 and 281.9 (?·cm)-1 for 2.5 and 5 wt% F, respectively, indicating that the films exhibited an n-type semiconducting nature. A systematic study on the influence of film thickness and doping content on the properties of SnO2:F thin films deposited by ultrasonic spray was reported.

Rahal, Achour; Benramache, Said; Benhaoua, Boubaker

2013-09-01

377

Catalytic pyrolysis using UZM-39 aluminosilicate zeolite  

DOEpatents

A new family of coherently grown composites of TUN and IMF zeotypes has been synthesized and shown to be effective catalysts for catalytic pyrolysis of biomass. These zeolites are represented by the empirical formula. Na.sub.nM.sub.m.sup.n+R.sub.rQ.sub.qAl.sub.1-xE.sub.xSi.sub.yO.s- ub.z where M represents zinc or a metal or metals from Group 1, Group 2, Group 3 or the lanthanide series of the periodic table, R is an A,.OMEGA.-dihalosubstituted paraffin such as 1,4-dibromobutane, Q is a neutral amine containing 5 or fewer carbon atoms such as 1-methylpyrrolidine and E is a framework element such as gallium. The process involves contacting a carbonaceous biomass feedstock with UZM-39 at pyrolysis conditions to produce pyrolysis gases comprising hydrocarbons. The catalyst catalyzes a deoxygenation reaction converting oxygenated hydrocarbons into hydrocarbons and removing the oxygen as carbon oxides and water. A portion of the pyrolysis gases is condensed to produce low oxygen biomass-derived pyrolysis oil.

Nicholas, Christopher P; Boldingh, Edwin P

2014-10-07

378

Pyrolysis of waste tyres: a review.  

PubMed

Approximately 1.5 billion tyres are produced each year which will eventually enter the waste stream representing a major potential waste and environmental problem. However, there is growing interest in pyrolysis as a technology to treat tyres to produce valuable oil, char and gas products. The most common reactors used are fixed-bed (batch), screw kiln, rotary kiln, vacuum and fluidised-bed. The key influence on the product yield, and gas and oil composition, is the type of reactor used which in turn determines the temperature and heating rate. Tyre pyrolysis oil is chemically very complex containing aliphatic, aromatic, hetero-atom and polar fractions. The fuel characteristics of the tyre oil shows that it is similar to a gas oil or light fuel oil and has been successfully combusted in test furnaces and engines. The main gases produced from the pyrolysis of waste tyres are H(2), C(1)-C(4) hydrocarbons, CO(2), CO and H(2)S. Upgrading tyre pyrolysis products to high value products has concentrated on char upgrading to higher quality carbon black and to activated carbon. The use of catalysts to upgrade the oil to a aromatic-rich chemical feedstock or the production of hydrogen from waste tyres has also been reported. Examples of commercial and semi-commercial scale tyre pyrolysis systems show that small scale batch reactors and continuous rotary kiln reactors have been developed to commercial scale. PMID:23735607

Williams, Paul T

2013-08-01

379

Catalytic pyrolysis using UZM-39 aluminosilicate zeolite  

DOEpatents

A new family of coherently grown composites of TUN and IMF zeotypes has been synthesized and show to be effective catalysts for catalytic pyrolysis of biomass. These zeolites are represented by the empirical formula. Na.sub.nM.sub.m.sup.n+R.sub.rQ.sub.qAl.sub1-xE.sub.xSi.sub.yO.s- ub.z where M represents zinc or a metal or metals from Group 1, Group 2, Group 3 or the lanthanide series of the periodic table, R is an A,.OMEGA.-dihalosubstituted paraffin such as 1,4-dibromobutane, Q is a neutral amine containing 5 or fewer carbon atoms such as 1-methylpyrrolidine and E is a framework element such as gallium. The process involves contacting a carbonaceous biomass feedstock with UZM-39 at pyrolysis conditions to produce pyrolysis gases comprising hydrocarbons. The catalyst catalyzes a deoxygenation reaction converting oxygenated hyrdocarbons into hydrocarbons removing the oxygen as carbon oxides and water. A portion of the pyrolysis gases is condensed to produce low oxygen biomass-derived pyrolysis oil.

Nicholas, Christpher P; Boldingh, Edwin P

2013-12-17

380

Synthesis of advanced materials for bio-oil production from rice straw by pyrolysis  

NASA Astrophysics Data System (ADS)

Bio-oil from rice straw is produced by pyrolysis with and without solid acid catalysts. Solid acid catalysts used in rice straw pyrolysis synthesis were the diatomite acidified by an 'atomic implantation method' and nano-sized porous Al-SBA1SBA: Santa Barbara Amorphous type mesoporous silica.-15. Catalysts were characterized by a field emission-scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), infrared spectroscopy (IR), N2 adsorption/desorption, differential thermal analysis/thermogravimetric analysis (DTA/TGA) and NH3 temperature programmed desorption (NH3-TPD). The obtained results revealed that a similar bio-oil yield (liquid product) of 44–48% can be reached by pyrolysis in the presence of solid acid catalysts at 450?°C compared to that of pyrolysis without catalyst at 550?°C. Moreover, a low yield of gas product was observed. These results show significant potential applications of solid acid catalysts for the improvement of bio-oil yield in the pyrolysis of rice straw.

Phuong Dang, Tuyet; Le, Gia Hy; Thu Giang Pham, Thi; Kien Nguyen, Trung; Canh Dao, Duc; Vu, Thi Minh Hong; Thu Thuy Hoang, Thi; Hoa Tran, Thi Kim; Vu, Anh Tuan

2011-12-01

381

Emulsions from Aerosol Sprays  

Microsoft Academic Search

An electrostatic emulsification apparatus has been designed for the purpose of studying diffusion from oil droplets which have a mean size in the range of ?1.5–3.5 ?m, with standard deviations of 40–50%. The emulsification technique involves the collection of a spray of electrically charged oil droplets onto a rotating water film which is sustained from a reservoir. In this way,

Rudy Hengelmolen; Brian Vincent; Graham Hassall

1997-01-01

382

Tissue Paper Spray Art  

NSDL National Science Digital Library

In this activity, learners observe color mixing and absorbency using colored tissue paper and spray bottles. Learners create collages out of colored tissue paper shapes and then lightly mist the tissue paper with water. When the learners remove the colored tissue, a colorful print appears. Use this activity to illustrate how materials absorb water as well as how colors can mix to form new colors.

Museum, Kohl C.

2012-01-01

383

Vacuum plasma spray coating  

NASA Technical Reports Server (NTRS)

Currently, protective plasma spray coatings are applied to space shuttle main engine turbine blades of high-performance nickel alloys by an air plasma spray process. Originally, a ceramic coating of yttria-stabilized zirconia (ZrO2.12Y2O3) was applied for thermal protection, but was removed because of severe spalling. In vacuum plasma spray coating, plasma coatings of nickel-chromium-aluminum-yttrium (NiCrAlY) are applied in a reduced atmosphere of argon/helium. These enhanced coatings showed no spalling after 40 MSFC burner rig thermal shock cycles between 927 C (1700 F) and -253 C (-423 F), while current coatings spalled during 5 to 25 test cycles. Subsequently, a process was developed for applying a durable thermal barrier coating of ZrO2.8Y2O3 to the turbine blades of first-stage high-pressure fuel turbopumps utilizing the enhanced NiCrAlY bond-coating process. NiCrAlY bond coating is applied first, with ZrO2.8Y2O3 added sequentially in increasing amounts until a thermal barrier coating is obtained. The enchanced thermal barrier coating has successfully passed 40 burner rig thermal shock cycles.

Holmes, Richard R.; Mckechnie, Timothy N.

1989-01-01

384

Composition of gases released during olive stones pyrolysis  

Microsoft Academic Search

The main aim of this work is to study the variation in the composition of the gas mixture released during olive stones pyrolysis as a function of the temperature. Pyrolysis was carried out in a Gray-King type furnace and in a microbalance for TG\\/DTG studies. The pyrolysis products were fractionated into char, liquids and gases, the latter being analyzed by

M. C Blanco López; C. G Blanco; A Mart??nez-Alonso; J. M. D Tascón

2002-01-01

385

Pyrolysis of the Moroccan (Tarfaya) oil shales under microwave irradiation  

Microsoft Academic Search

The pyrolysis studies of the Tarfaya (Morocco) oil shales were performed using an installation specially adapted to the pyrolysis of oil shale under microwave irradiation.The microwave cavity and the reactor were designed to assure a good transfer of the microwave energy to the material and, to study the pyrolysis of the oil shales. The results obtained revealed that this process

K. El harfi; A. Mokhlisse; M. B. Chanâa; A. Outzourhit

2000-01-01

386

Pyrolysis of Sawdust, Rice Husk and Sugarcane Bagasse: Kinetic Modeling and Estimation of Kinetic Parameters using Different Optimization Tools  

NASA Astrophysics Data System (ADS)

The present study provides the kinetic model to describe the pyrolysis of sawdust, rice-husk and sugarcane bagasse as biomass. The kinetic scheme used for modelling of primary pyrolysis consisting of the two parallel reactions giving gaseous volatiles and solid char. Estimation of kinetic parameters for pyrolysis process has been carried out for temperature range of 773-1,173 K. As there are serious issues regarding non-convergence of some of the methods or solutions converging to local-optima, the proposed kinetic model is optimized to predict the best values of kinetic parameters for the system using three approaches—Two-dimensional surface fitting non-linear regression technique, MS-Excel Solver Tool and COMSOL software. The model predictions are in agreement with experimental data over a wide range of pyrolysis conditions. The estimated value of kinetic parameters are compared with earlier researchers and found to be matching well.

Khonde, Ruta Dhanram; Chaurasia, Ashish Subhash

2015-01-01

387

Production of Gasoline and Diesel from Biomass via Fast Pyrolysis, Hydrotreating and Hydrocracking: A Design Case  

SciTech Connect

The purpose of this study is to evaluate a processing pathway for converting biomass into infrastructure-compatible hydrocarbon biofuels. This design case investigates production of fast pyrolysis oil from biomass and the upgrading of that bio-oil as a means for generating infrastructure-ready renewable gasoline and diesel fuels. This study has been conducted using the same methodology and underlying basis assumptions as the previous design cases for ethanol. The overall concept and specific processing steps were selected because significant data on this approach exists in the public literature. The analysis evaluates technology that has been demonstrated at the laboratory scale or is in early stages of commercialization. The fast pyrolysis of biomass is already at an early stage of commercialization, while upgrading bio-oil to transportation fuels has only been demonstrated in the laboratory and at small engineering development scale. Advanced methods of pyrolysis, which are under development, are not evaluated in this study. These may be the subject of subsequent analysis by OBP. The plant is designed to use 2000 dry metric tons/day of hybrid poplar wood chips to produce 76 million gallons/year of gasoline and diesel. The processing steps include: 1.Feed drying and size reduction 2.Fast pyrolysis to a highly oxygenated liquid product 3.Hydrotreating of the fast pyrolysis oil to a stable hydrocarbon oil with less than 2% oxygen 4.Hydrocracking of the heavy portion of the stable hydrocarbon oil 5.Distillation of the hydrotreated and hydrocracked oil into gasoline and diesel fuel blendstocks 6. Hydrogen production to support the hydrotreater reactors. The “as received” feedstock to the pyrolysis plant will be “reactor ready.” This development will likely further decrease the cost of producing the fuel. An important sensitivity is the possibility of co-locating the plant with an existing refinery. In this case, the plant consists only of the first three steps: feed prep, fast pyrolysis, and upgrading. Stabilized, upgraded pyrolysis oil is transferred to the refinery for separation and finishing into motor fuels. The off-gas from the hydrotreaters is also transferred to the refinery, and in return the refinery provides lower-cost hydrogen for the hydrotreaters. This reduces the capital investment. Production costs near $2/gal (in 2007 dollars) and petroleum industry infrastructure-ready products make the production and upgrading of pyrolysis oil to hydrocarbon fuels an economically attractive source of renewable fuels. The study also identifies technical areas where additional research can potentially lead to further cost improvements.

Jones, Susanne B.; Valkenburt, Corinne; Walton, Christie W.; Elliott, Douglas C.; Holladay, Johnathan E.; Stevens, Don J.; Kinchin, Christopher; Czernik, Stefan

2009-02-28

388

Production of Gasoline and Diesel from Biomass via Fast Pyrolysis, Hydrotreating and Hydrocracking: A Design Case  

SciTech Connect

The purpose of this study is to evaluate a processing pathway for converting biomass into infrastructure-compatible hydrocarbon biofuels. This design case investigates production of fast pyrolysis oil from biomass and the upgrading of that bio-oil as a means for generating infrastructure-ready renewable gasoline and diesel fuels. This study has been conducted using similar methodology and underlying basis assumptions as the previous design cases for ethanol. The overall concept and specific processing steps were selected because significant data on this approach exists in the public literature. The analysis evaluates technology that has been demonstrated at the laboratory scale or is in early stages of commercialization. The fast pyrolysis of biomass is already at an early stage of commercialization, while upgrading bio-oil to transportation fuels has only been demonstrated in the laboratory and at small engineering development scale. Advanced methods of pyrolysis, which are under development, are not evaluated in this study. These may be the subject of subsequent analysis by OBP. The plant is designed to use 2000 dry metric tons/day of hybrid poplar wood chips to produce 76 million gallons/year of gasoline and diesel. The processing steps include: 1.Feed drying and size reduction 2.Fast pyrolysis to a highly oxygenated liquid product 3.Hydrotreating of the fast pyrolysis oil to a stable hydrocarbon oil with less than 2% oxygen 4.Hydrocracking of the heavy portion of the stable hydrocarbon oil 5.Distillation of the hydrotreated and hydrocracked oil into gasoline and diesel fuel blendstocks 6. Hydrogen production to support the hydrotreater reactors. The "as received" feedstock to the pyrolysis plant will be "reactor ready". This development will likely further decrease the cost of producing the fuel. An important sensitivity is the possibility of co-locating the plant with an existing refinery. In this case, the plant consists only of the first three steps: feed prep, fast pyrolysis, and upgrading. Stabilized, upgraded pyrolysis oil is transferred to the refinery for separation and finishing into motor fuels. The off-gas from the hydrotreaters is also transferred to the refinery, and in return the refinery provides lower-cost hydrogen for the hydrotreaters. This reduces the capital investment. Production costs near $2/gal (in 2007 dollars) and petroleum industry infrastructure-ready products make the production and upgrading of pyrolysis oil to hydrocarbon fuels an economically attractive source of renewable fuels. The study also identifies technical areas where additional research can potentially lead to further cost improvements.

Jones, Susanne B.; Valkenburt, Corinne; Walton, Christie W.; Elliott, Douglas C.; Holladay, Johnathan E.; Stevens, Don J.; Kinchin, Christopher; Czernik, Stefan

2009-02-25

389

Behavior of chlorine during coal pyrolysis  

USGS Publications Warehouse

The behavior of chlorine in Illinois coals during pyrolysis was evaluated by combined thermo-gravimetry-Fourier transform infrared spectroscopy-ion chromatography (TG-FTIR-IC) techniques. It was found that more than 90% of chlorine in Illinois coals (IBC-103, 105, 106, and 109) was liberated as HCl gas during pyrolysis from 300 to 600??C, with the rate reaching a maximum at 440 ??C. Similarity of the HCl and NH3 release profiles during pyrolysis of IBC-109 supports the hypothesis that the chlorine in coal may be associated with nitrogen and the chlorine is probably bonded to the basic nitrogen sites on the inner walls of coal micropores. ?? 1994 American Chemical Society.

Shao, D.; Hutchinson, E.J.; Cao, H.; Pan, W.-P.; Chou, C.-L.

1994-01-01

390

Pyrolysis and volatilization of cocaine  

SciTech Connect

The increasing popularity of inhaling cocaine vapor prompted the present study, to determine cocaine's fate during this process. The free base of (3H)cocaine (1 microCi/50 mg) was added to a glass pipe, which was then heated in a furnace to simulate freebasing. Negative pressure was used to draw the vapor through a series of glass wool, ethanol, acidic, and basic traps. Air flow rate and temperature were found to have profound effects on the volatilization and pyrolysis of cocaine. At a temperature of 260 degrees C and a flow rate of 400 mL/min, 37% of the radioactivity remained in the pipe, 39% was found in the glass wool trap, and less than 1% in the remainder of the volatilization apparatus after a 10-min volatilization. Reducing the air flow rate to 100 mL/min reduced the amount of radioactivity collected in the glass wool trap to less than 10% of the starting material and increased the amount that remained in the pipe to 58%. GC/MS analysis of the contents of the glass wool trap after volatilization at 260 degrees C and a flow rate of 400 mL/min revealed that 60% of the cocaine remained intact, while approximately 6 and 2% of the starting material was recovered as benzoic acid and methylecgonidine, respectively. As the temperature was increased to 650 degrees C, benzoic acid and methylecgonidine accounted for 83 and 89% of the starting material, respectively, whereas only 2% of the cocaine remained intact. Quantitation of cocaine in the vapor during the course of volatilization revealed high concentrations during the first two min and low concentrations for the remaining time.

Martin, B.R.; Lue, L.P.; Boni, J.P. (Virginia Commonwealth Univ., Richmond (USA))

1989-05-01

391

Pyrolysis of Phenolic Impregnated Carbon Ablator (PICA).  

PubMed

Molar yields of the pyrolysis products of thermal protection systems (TPSs) are needed in order to improve high fidelity material response models. The volatile chemical species evolved during the pyrolysis of a TPS composite, phenolic impregnated carbon ablator (PICA), have been probed in situ by mass spectrometry in the temperature range 100 to 935 °C. The relative molar yields of the desorbing species as a function of temperature were derived by fitting the mass spectra, and the observed trends are interpreted in light of the results of earlier mechanistic studies on the pyrolysis of phenolic resins. The temperature-dependent product evolution was consistent with earlier descriptions of three stages of pyrolysis, with each stage corresponding to a temperature range. The two main products observed were H2O and CO, with their maximum yields occurring at ?350 °C and ?450 °C, respectively. Other significant products were CH4, CO2, and phenol and its methylated derivatives; these products tended to desorb concurrently with H2O and CO, over the range from about 200 to 600 °C. H2 is presumed to be the main product, especially at the highest pyrolysis temperatures used, but the relative molar yield of H2 was not quantified. The observation of a much higher yield of CO than CH4 suggests the presence of significant hydroxyl group substitution on phenol prior to the synthesis of the phenolic resin used in PICA. The detection of CH4 in combination with the methylated derivatives of phenol suggests that the phenol also has some degree of methyl substitution. The methodology developed is suitable for real-time measurements of PICA pyrolysis and should lend itself well to the validation of nonequilibrium models whose aim is to simulate the response of TPS materials during atmospheric entry of spacecraft. PMID:25490209

Bessire, Brody K; Lahankar, Sridhar A; Minton, Timothy K

2015-01-28

392

Hypergolic bipropellant spray combustion and flow modelling in rocket engines  

NASA Technical Reports Server (NTRS)

A predictive tool for hypergolic bipropellant spray combustion and flow evolution in small rocket combustion chambers is described. It encompasses a computational technique for the gas-phase governing equations, a discrete particle method for liquid bipropellant sprays, and constitutive models for combustion chemistry, interphase exchanges, and unlike impinging hypergolic spray interactions. Emphasis is placed on the phenomenological modeling of the hypergolic liquid bipropellant gasification processes. Sample computations with the N2H4-N2O4 propellant system are given in order to show some of the capabilities and inadequacies of this tool.

Larosiliere, Louis M.; Litchford, Ron J.; Jeng, San-Mou

1990-01-01

393

Consider Upgrading Pyrolysis Oils Into Renewale Fuels  

SciTech Connect

To enable a sustained supply of biomass-based transportation fuels, the capability to process feedstocks outside the food chain must be developed. Significant industry efforts are underway to develop these new technologies, such as converting cellulosic wastes to ethanol. An alternate route being pursued involves using a fast pyrolysis operation to generate pyrolysis oil (pyoil for short). Current efforts are focused on developing a thermochemical platform to convert pyoils to renewable gasoline, diesel and jet fuel. The fuels produced will be indistinguishable from their fossil fuel counterparts and, therefore, will be compatible with existing transport and distribution infrastructure.

Holmgren, J.; Marinangeli, R.; Nair, P.; Elliott, D.; Bain, R.

2008-09-01

394

Pyrolysis Of Mustard De-Oiled Cake  

E-print Network

Abstract: A fixed bed pyrolysis has been designed and fabricated for obtaining liquid fuel from mustard de-oiled cake. Thermal pyrolysis of mustard deoiled cake were carried out in a semi batch reactor made up of stainless steel at temperature range from 450 0 C to 600 0 C and at a rate of 150C /min to produce bio-fuel. The maximum yield of oil was 51 % on wt. % basis for mustard de-oiled cake, it was obtained at a temperature of 600 0 C with a less completion time. The fuel analysis of oil reveals that this pyrolytic oil can be used as fuel.

Anil Kumar; Sewa Singh

395

Pyrolysis kinetics for the Bakken shale  

SciTech Connect

Pyrolysis kinetics are reported and compared for rapid open pyrolysis experiments: Py-TG-FTIR, Py-FID, and Py-MS. Where the type of information obtained overlapped, the results were very similar. The principal activation energy for total hydrocarbon generation using a parallel reaction model is 52 kcal/mol. As with most petroleum source rocks, carbon dioxide generation tends to lead oil formation while ethene and methane generation tend to lag oil generation. The midpoint of oil generation for a geological heating rate of 3 {degrees}C/m.y. is predicted to be between 130 and 140{degrees}C. 5 refs., 4 figs., 1 tab.

Burnham, A.K.

1992-01-01

396

Photomicrographic Studies of Fuel Sprays  

NASA Technical Reports Server (NTRS)

A large number of photomicrographs of fuel sprays were taken for the purpose of studying the spray structure and the process of spray formation. They were taken at magnifying powers of 2.5, 3.25, and 10, using a spark discharge of very short duration for illumination. Several types and sizes of nozzles were investigated, different liquids were used, and a wide range of injection pressures was employed. The sprays were photographed as they were injected into a glass-walled chamber in which the air density was varied from 14 atmospheres to 0.0013 atmosphere.

Lee, Dana W; Spencer, Robert C

1934-01-01

397

Steel surface modification with plasma spraying electrothermal installation using a liquid electrode  

NASA Astrophysics Data System (ADS)

Recently, much attention has been paid to different processes using low- temperature plasma, and in particular, the process of plasma spraying. Despite the fact that the plasma spraying method has been established for a relatively long time, there are several unsolved issues in this field that are associated with the choice of the optimal spraying modes. It is connected with the fact that the development of optimal spraying process modes is a rather difficult task, since the problem of creating an optimal design for the plasmatron is not solved yet. In this article the technological plasma plant with liquid electrode is discussed, which provides a plasma spray with a temperature up to 5000°C and lengths up to 100 mm. Engineered installation allows to carry out plasma spraying of steel surface. The process and parameters of plasma spraying optimal modes are examined in the article.

Khafizov, A. A.; Valiev, R. I.; Shakirov, Yu I.; Valiev, R. A.

2014-11-01

398

Structure and morphology of sprayed ZnS thin films  

NASA Astrophysics Data System (ADS)

Zinc sulphide (ZnS) thin films have been prepared on Pyrex substrates by the spray pyrolysis technique using zinc chloride and thiourea as precursors. The depositions were carried out on substrates heated at 450 °C. The films were then annealed under sulphur atmosphere for one hour at 450 or 500 °C. This process allows one to obtain well-crystallized cubic-type -ZnS thin films. The crystallites exhibit preferential orientation along the (111) direction. The undesirable ZnO phase does not appear in the X-ray diffraction spectra of the films. Microprobe analysis shows that a nearly stoichiometric composition is obtained using these annealing temperatures. Moreover only a surface contamination by oxygen of such films was found as determined from X-ray photoelectron spectroscopy measurements.

Ben Nasrallah, T.; Amlouk, M.; Bernède, J. C.; Belgacem, S.

2004-11-01

399

Spray nozzle designs for agricultural aviation applications. [relation of drop size to spray characteristics and nozzle efficiency  

NASA Technical Reports Server (NTRS)

Techniques of generating monodisperse sprays and information concerning chemical liquids used in agricultural aviation are surveyed. The periodic dispersion of liquid jet, the spinning disk method, and ultrasonic atomization are the techniques discussed. Conceptually designed spray nozzles for generating monodisperse sprays are assessed. These are based on the classification of the drops using centrifugal force, on using two opposing liquid laden air jets, and on operating a spinning disk at an overloaded flow. Performance requirements for the designs are described and estimates of the operational characteristics are presented.

Lee, K. W.; Putnam, A. A.; Gieseke, J. A.; Golovin, M. N.; Hale, J. A.

1979-01-01

400

Effect of wastewater treatment processes on the pyrolysis properties of the pyrolysis tars from sewage sludges  

NASA Astrophysics Data System (ADS)

The pyrolysis properties of five different pyrolysis tars, which the tars from 1# to 5# are obtained by pyrolyzing the sewage sludges of anaerobic digestion and indigestion from the A2/O wastewater treatment process, those from the activated sludge process and the indigested sludge from the continuous SBR process respectively, were studied by thermal gravimetric analysis at a heating rate of 10 °C/min in the nitrogen atmosphere. The results show that the pyrolysis processes of the pyrolysis tars of 1#, 2#, 3# and 5# all can be divided into four stages: the stages of light organic compounds releasing, heavy polar organic compounds decomposition, heavy organic compounds decomposition and the residual organic compounds decomposition. However, the process of 4# pyrolysis tar is only divided into three stages: the stages of light organic compounds releasing, decomposition of heavy polar organic compounds and the residual heavy organic compounds respectively. Both the sludge anaerobic digestion and the "anaerobic" process in wastewater treatment processes make the content of light organic compounds in tars decrease, but make that of heavy organic compounds with complex structure increase. Besides, both make the pyrolysis properties of the tars become worse. The pyrolysis reaction mechanisms of the five pyrolysis tars have been studied with Coats-Redfern equation. It shows that there are the same mechanism functions in the first stage for the five tars and in the second and third stage for the tars of 1#, 2#, 3# and 5#, which is different with the function in the second stage for 4# tar. The five tars are easy to volatile.

Wu, Xia; Xie, Li-Ping; Li, Xin-Yu; Dai, Xiao-Hong; Fei, Xue-Ning; Jiang, Yuan-Guang

2011-06-01

401

Novel sorbent materials for environmental remediation via Pyrolysis of biomass  

NASA Astrophysics Data System (ADS)

One of the major challenges facing society at this moment is the transition from a non-sustainable, fossil resources-based economy to a sustainable bio-based economy. By producing multiple products, a biorefinery can take advantage of the differences in biomass components and intermediates and maximize the value derived from the biomass feedstock. The high-value products enhance profitability, the high-volume fuel helps meet national energy needs, and the power production reduces costs and avoids greenhouse-gas emissions From pyrolysis, besides gas and liquid products a solid product - char, is derived as well. This char contains the non converted carbon and can be used for activated carbon production and/or as additive in composite material production. Commercially available activated carbons are still considered expensive due to the use of non-renewable and relatively expensive starting material such as coal. The present study describes pyrolysis as a method to produce high added value carbon materials such as activated carbons (AC) from agricultural residues pyrolysis. Olive kernel has been investigated as the precursor of the above materials. The produced activated carbon was characterized by proximate and ultimate analyses, BET method and porosity estimation. Furthermore, its adsorption of pesticide compound in aqueous solution by was studied. Pyrolysis of olive kernel was conducted at 800 oC for 45min in a fixed reactor. For the production of the activated carbon the pyrolytic char was physically activated under steam in the presence of CO2 at 970oC for 3 h in a bench scale reactor. The active carbons obtained from both scales were characterized by N2 adsorption at 77 K, methyl-blue adsorption (MB adsorption) at room temperature and SEM analysis. Surface area and MB adsorption were found to increase with the degree of burn-off. The surface area of the activated carbons was found to increase up to 1500 m2/g at a burn-off level of 60-65wt.%, while SEM analysis showed the appearance of micropores to mesopores in the produced tire active carbons. Activated carbon prepared from olive kernel is a super active carbon and used as an adsorbent for the removal of pesticide from aqueous solutions (Bromopropylate). The higher removal achieved was 100% in 60 min. The produced activated carbon from agricultural residue was proved to be very effective for gas and water stream purification. Biomass can give a wide spectrum of fuels and materials in the integrated concept of biorefinery

Zabaniotou, Anastasia

2013-04-01

402

Hydrogen isotope ratio determinations in hydrocarbons using the pyrolysis preparation technique  

Microsoft Academic Search

This report describes the successful development of a new and efficient method for the determination of stable hydrogen isotope composition of the Cââ aliphatic fraction of crude oils. This new technique makes use of high-temperature pyrolysis reactions in which the aliphatic hydrocarbons in oils are directly converted to hydrogen gas (plus methane and graphite) followed by direct measurement for hydrogen

Zvi. Sofer; Craig F. Schiefelbein

1986-01-01

403

Conversion of agricultural bio-mass to energy via catalyst assisted pyrolysis  

Technology Transfer Automated Retrieval System (TEKTRAN)

One method for converting agricultural waste or specifically grown crops to energy is by heating this “bio-mass” to high temperatures in the absence of oxygen, a process called pyrolysis. Burning bio-mass in the presence of oxygen produces mostly carbon dioxide and water. Burning biomass in the ab...

404

The reduction and control technology of tar during biomass gasification\\/pyrolysis: An overview  

Microsoft Academic Search

Biomass is an important primary energy source as well as renewable energy source. As the most promising biomass utilization method, gasification\\/pyrolysis produces not only useful fuel gases, char and chemicals, but also some byproducts like fly ash, NOx, SO2 and tar. Tar in the product gases will condense at low temperature, and lead to clogged or blockage in fuel lines,

Jun Han; Heejoon Kim

2008-01-01

405

Application of extended surfaces in pyrolysis coils  

SciTech Connect

This paper describes the utilization of extended surface tubing on the pyrolysis coil design for high selectivity and high capacity heaters. The results of heat transfer and pressure drop experiments for this new material are reviewed and utilization of this material in new heaters is discussed.

Albano, J.V.; Sundaram, K.; Maddock, M.J. (The Lummus Crest Inc., Bloomfield, NJ (US))

1988-01-01

406

Pyrolysis of lipids using various catalysts  

Technology Transfer Automated Retrieval System (TEKTRAN)

A specific pursuit of the thermochemical (combustion, gasification, pyrolysis, and liquefaction) conversion of biomass to energy research effort is the potential of converting lipids to alkanes, petroleum-like fuels and chemicals. Arguments can be made for, and against, the use of agricultural lipi...

407

Flash vacuum pyrolysis of lignin model compounds  

SciTech Connect

Despite the extensive research into the pyrolysis of lignin, the underlying chemical reactions that lead to product formation are poorly understood. Detailed mechanistic studies on the pyrolysis of biomass and lignin under conditions relevant to current process conditions could provide insight into utilizing this renewable resource for the production of chemicals and fuel. Currently, flash or fast pyrolysis is the most promising process to maximize the yields of liquid products (up to 80 wt %) from biomass by rapidly heating the substrate to moderate temperatures, typically 500{degrees}C, for short residence times, typically less than two seconds. To provide mechanistic insight into the primary reaction pathways under process relevant conditions, we are investigating the flash vacuum pyrolysis (FVP) of lignin model compounds that contain a {beta}-ether. linkage and {alpha}- or {gamma}-alcohol, which are key structural elements in lignin. The dominant products from the FVP of PhCH{sub 2}CH{sub 2}OPh (PPE), PhC(OH)HCH{sub 2}OPh, and PhCH{sub 2}CH(CH{sub 2}OH)OPh at 500{degrees}C can be attributed to homolysis of the weakest bond in the molecule (C-O bond) or 1,2-elimination. Surprisingly, the hydroxy-substituent dramatically increases the decomposition of PPE. It is proposed that internal hydrogen bonding is accelerating the reaction.

Cooney, M.J.; Britt, P.F.; Buchanan, A.C. III

1997-03-01

408

Pyrolysis mechanisms of lignin model compounds  

SciTech Connect

The flash vacuum pyrolysis of lignin model compounds was studied under conditions optimized for the production of liquid products to provide mechanistic insight into the reaction pathways that lead to product formation. The major reaction products can be explained by cleavage of the C-O either linkage by a free radial or concerted 1,2-elimination.

Britt, P.F.; Buchanan, A.C. III; Cooney, M.J.

1997-06-01

409

Determination of polymer additives using analytical pyrolysis  

Microsoft Academic Search

When analyzing a polymeric material using pyrolysis-GC, the majority of the peaks seen are degradation products from the polymer matrix, but there may be specific compounds present resulting from the presence of antioxidants, plasticisers, stabilizers, flame retardants and other additives. Some of these compounds may be volatile or semi-volatile and appear as intact molecules, while others are larger and only

Karen D. Jansson; Charles P. Zawodny; Thomas P. Wampler

2007-01-01

410

Catalytic pyrolysis using UZM-44 aluminosilicate zeolite  

DOEpatents

A new family of aluminosilicate zeolites designated UZM-44 has been synthesized. These zeolites are represented by the empirical formula Na.sub.nM.sub.m.sup.k+T.sub.tAl.sub.1-xE.sub.xSi.sub.yO.sub.z where "n" is the mole ratio of Na to (Al+E), M represents a metal or metals from zinc, Group 1, Group 2, Group 3 and or the lanthanide series of the periodic table, "m" is the mole ratio of M to (Al+E), "k" is the average charge of the metal or metals M, T is the organic structure directing agent or agents, and E is a framework element such as gallium. The process involves contacting a carbonaceous biomass feedstock with UZM-44 at pyrolysis conditions to produce pyrolysis gases comprising hydrocarbons. The catalyst catalyzes a deoxygenation reaction converting oxygenated hydrocarbons into hydrocarbons and removing the oxygen as carbon oxides and water. A portion of the pyrolysis gases is condensed to produce low oxygen biomass-derived pyrolysis oil.

Nicholas, Christopher P; Boldingh, Edwin P

2013-12-17

411

Catalytic pyrolysis using UZM-44 aluminosilicate zeolite  

DOEpatents

A new family of aluminosilicate zeolites designated UZM-44 has been synthesized. These zeolites are represented by the empirical formula. Na.sub.nM.sub.m.sup.k+T.sub.tAl.sub.1-xE.sub.xSi.sub.yO.sub.z where "n" is the mole ratio of Na to (Al+E), M represents a metal or metals from zinc, Group 1, Group 2, Group 3 and or the lanthanide series of the periodic table, "m" is the mole ratio of M to (Al+E), "k" is the average charge of the metal or metals M, T is the organic structure directing agent or agents, and E is a framework element such as gallium. The process involves contacting a carbonaceous biomass feedstock with UZM-44 at pyrolysis conditions to produce pyrolysis gases comprising hydrocarbons. The catalyst catalyzes a deoxygenation reaction converting oxygenated hydrocarbons into hydrocarbons and removing the oxygen as carbon oxides and water. A portion of the pyrolysis gases is condensed to produce low oxygen biomass-derived pyrolysis oil.

Nicholas, Christopher P; Boldingh, Edwin P

2014-04-29

412

Vacuum pyrolysis of softwood and hardwood biomass  

Microsoft Academic Search

Softwood bark (SWBR) and hardwood rich in fibres (HWRF) biomass samples were used as model feedstocks to study the properties of bio-oils obtained by vacuum pyrolysis. The content and composition of extractives in the feedstocks were determined after fractionation into different classes of compounds using solvents of different polarities followed by GC\\/MS analysis. The content in cellulose, hemicellulose and lignin

M. Garcìa-Pérez; A. Chaala; H. Pakdel; D. Kretschmer; C. Roy

2007-01-01

413

Characterization of products obtained from pyrolysis and steam gasification of wood waste, RDF, and RPF.  

PubMed

Pyrolysis and steam gasification of woody biomass chip (WBC) obtained from construction and demolition wastes, refuse-derived fuel (RDF), and refuse paper and plastic fuel (RPF) were performed at various temperatures using a lab-scale instrument. The gas, liquid, and solid products were examined to determine their generation amounts, properties, and the carbon balance between raw material and products. The amount of product gas and its hydrogen concentration showed a considerable difference depending on pyrolysis and steam gasification at higher temperature. The reaction of steam and solid product, char, contributed to an increase in gas amount and hydrogen concentration. The amount of liquid products generated greatly depended on temperature rather than pyrolysis or steam gasification. The compositions of liquid product varied relying on raw materials used at 500°C but the polycyclic aromatic hydrocarbons became the major compounds at 900°C irrespective of the raw materials used. Almost fixed carbon (FC) of raw materials remained as solid products under pyrolysis condition whereas FC started to decompose at 700°C under steam gasification condition. For WBC, both char utilization by pyrolysis at low temperature (500°C) and syngas recovery by steam gasification at higher temperature (900°C) might be practical options. From the results of carbon balance of RDF and RPF, it was confirmed that the carbon conversion to liquid products conspicuously increased as the amount of plastic increased in the raw material. To recover feedstock from RPF, pyrolysis for oil recovery at low temperature (500°C) might be one of viable options. Steam gasification at 900°C could be an option but the method of tar reforming (e.g. catalyst utilization) should be considered. PMID:24246576

Hwang, In-Hee; Kobayashi, Jun; Kawamoto, Katsuya

2014-02-01

414

Thiophenic Sulfur Compounds Released During Coal Pyrolysis.  

PubMed

Thiophenic sulfur compounds are released during coal gasification, carbonization, and combustion. Previous studies indicate that thiophenic sulfur compounds degrade very slowly in the environment, and are more carcinogenic than polycyclic aromatic hydrocarbons and nitrogenous compounds. Therefore, it is very important to study the principle of thiophenic sulfur compounds during coal conversion, in order to control their emission and promote clean coal utilization. To realize this goal and understand the formation mechanism of thiophenic sulfur compounds, this study focused on the release behavior of thiophenic sulfur compounds during coal pyrolysis, which is an important phase for all coal thermal conversion processes. The pyrolyzer (CDS-5250) and gas chromatography-mass spectrometry (Focus GC-DSQII) were used to analyze thiophenic sulfur compounds in situ. Several coals with different coal ranks and sulfur contents were chosen as experimental samples, and thiophenic sulfur compounds of the gas produced during pyrolysis under different temperatures and heating rates were investigated. Levels of benzothiophene and dibenzothiophene were obtained during pyrolysis at temperatures ranging from 200°C to 1300°C, and heating rates ranging from 6°C/ms to 14°C/ms and 6°C/s to 14°C/s. Moreover, the relationship between the total amount of benzothiophene and dibenzothiophene released during coal pyrolysis and the organic sulfur content in coal was also discussed. This study is beneficial for understanding the formation and control of thiophenic sulfur compounds, since it provides a series of significant results that show the impact that operation conditions and organic sulfur content in coal have on the amount and species of thiophenic sulfur compounds produced during coal pyrolysis. PMID:23781126

Xing, Mengwen; Kong, Jiao; Dong, Jie; Jiao, Haili; Li, Fan

2013-06-01

415

User friendliness, efficiency & spray quality of stirrup pumps versus hand compression pumps for indoor residual spraying  

PubMed Central

Background & objectives: Indoor residual spraying (IRS) is a proven tool to reduce visceral leishmaniasis vectors in endemic villages. In India IRS is being done with stirrup pumps, whereas Nepal, Bangladesh, and other countries use compression pumps. The present study was conducted with the objectives to compare the efficiency, cost and user friendliness of stirrup and compression pumps. Methods: The study was carried out in Gorigawan village of the Vaishali district in north Bihar and included a total population of 3259 inhabitants in 605 households. Spraying with 50 per cent DDT was done by two teams with 6 persons per team under the supervision of investigators over 5 days with each type of pump (10 days in total using 2 stirrup pumps and 3 compression pumps) by the same sprayers in an alternate way. The spraying technique was observed using an observation check list, the number of houses and room surfaces sprayed was recorded and an interview with sprayers on their satisfaction with the two types of pumps was conducted. Results: On average, 65 houses were covered per day with the compression pump and 56 houses were covered with the stirrup pump. The surface area sprayed per squad per day was higher for the compression pump (4636 m2) than for the stirrup pump (4102 m2). Observation showed that it was easy to maintain the spray swath with the compression pump but very difficult with the stirrup pump. The wastage of insecticide suspension was negligible for the compression pump but high for the stirrup pump. Interpretation & conclusions: The compression pump was found to be more user friendly due to its lower weight, easier to operate, lower operation cost, higher safety and better efficiency in terms of discharge rate and higher area coverage than the stirrup pump. PMID:24056601

Kumar, Vijay; Kesari, Shreekant; Chowdhury, Rajib; Kumar, Sanjiv; Sinha, Gunjan; Hussain, Saddam; Huda, M. Mamun; Kroeger, Axel; Das, Pradeep

2013-01-01

416

Influence of Spraying Parameters on the Microstructure and Properties of Plasma-sprayed Al2O3/40%TiO2 Coating  

NASA Astrophysics Data System (ADS)

In this paper, the influences of parameters such as spraying voltage, spraying current, primary gas feed rate and spraying distance on the properties of plasma-sprayed Al2O3-40 wt.%TiO2 composite ceramic coating were studied by using orthogonal experimental design. The influence sequences of the parameters on the properties of plasma-sprayed Al2O3-40 wt.%TiO2 coating are: spraying distance, spraying voltage, spraying current, argon gas flow rate. The optimum parameters were determined: spraying distance 100 mm, spraying current 440 A, spraying voltage 120 V, and argon gas flow rate 3.0 m3/h. Scanning electronic microscope was used to observe the surface and cross-section morphologies of the Al2O3-40 wt.%TiO2 coating prepared by using the optimum parameters. The phase structure was analyzed by X ray diffraction. The through-thickness microhardness was measured by microhardness instrument. The bonding strength between the coating and substrate was determined by dual tensile test method. The porosity was measured by image analysis method. The results showed that the plasma-sprayed Al2O3-40 wt.%TiO2 composite ceramic coating has a dense structure with the porosity of 1.5%. In addition, the coating has typical layered structure. Al2O3-rich area and TiO2-rich area exhibiting different colors have homogeneous distribution and good combination. Due to the function of NiAl/AlSi bond coating, the bonding strength between the Al2O3- 40 wt.% TiO2 coating and substrate reaches 45 MPa. The coating is mainly composed of ?-Al2O3 metastable phase, ?-Al2O3 stable phase, Ti8O15 and Al2TiO5.

Kang, J. J.; Xu, B. S.; Wang, H. D.; Wang, C. B.

417

Preparation of Chitosan and Water-Soluble Chitosan Microspheres via Spray-Drying Method to Lower Blood Lipids in Rats Fed with High-Fat Diets  

PubMed Central

This experiment aimed to investigate the effects of the chitosan (CTS) and water-soluble chitosan (WSC) microspheres on plasma lipids in male Sprague-Dawley rats fed with high-fat diets. CTS microspheres and WSC microspheres were prepared by the spray-drying technique. Scanning electron microscopy (SEM) micrographs showed that the microspheres were nearly spherical in shape. The mean size of CTS microspheres was 4.07 ?m (varying from 1.50 to 7.21 ?m) and of WSC microspheres was 2.00 ?m (varying from 0.85 to 3.58 ?m). The rats were classified into eight groups (n = 8) and were fed with high-fat diets for two weeks to establish the hyperlipidemic condition and were then treated with CTS microspheres and WSC microspheres, CTS and WSC for four weeks. The results showed that CTS and WSC microspheres reduced blood lipids and plasma viscosity and increased the serum superoxide dismutase (SOD) levels significantly. This study is the first report of the lipid-lowering effects of CTS and WSC microspheres. CTS and WSC microspheres were found to be more effective in improving hyperlipidemia in rats than common CTS and WSC. PMID:23429200

Tao, Yi; Zhang, Hong-Liang; Hu, Yin-Ming; Wan, Shuo; Su, Zheng-Quan

2013-01-01

418

Demonstration of split-flow ventilation and recirculation as flow-reduction methods in an Air Force paint spray booth. Final technical report, February 1991-October 1992  

SciTech Connect

During a series of painting operations in a horizontal-flow paint spray booth at Travis AFB, CA, baseline concentrations of four classes of toxic airborne pollutants were measured at 24 locations across a plane immediately forward of the exhaust filters, in the exhaust duct, and inside and outside the respirator in the painter`s breathing zone (BZ). The resulting data were analyzed and used to design a modified ventilation system that (1) separates a portion of the exhaust exiting the lower portion of the booth, which contains a concentration of toxic pollutants greater than the average at the exhaust plane (split-flow); and (2) provides an option to return the flow from the upper portion of the exhaust to the intake plenum for mixing with fresh air and recirculation through the booth (recirculation). After critical review by cognizant Air Force offices and an experimental demonstration showing that a flame ionization detector monitoring the air entering the booth is able to detect excursions above the equivalent exposure limit for the solvents in the paint, the exhaust duct was reconfigured for split-flow and recirculating ventilation. A volunteer painter was briefed on the increased risk of exposure during recirculation, and on the purposes and possible benefits of this study. He then signed an informed consent form before participating in the recirculation tests. A series of tests generally equivalent to the baseline series was conducted during split-flow and recirculating ventilation, and three tests were performed during only split-flow ventilation.

Hughes, S.; Ayer, J.; Sutay, R.

1994-07-01

419

Chemical sprays as a method for improvement in microbiological quality and shelf-life of fresh sheep and goat meats during refrigeration storage (5-7°C).  

PubMed

The shelf-life of meats from freshly slaughtered sheep and goat carcasses at 5-7 °C was extended after spraying (pressure 3 kg/cm(2)) the carcasses with solution 'B' containing potassium sorbate, sodium acetate, sodium citrate, sodium lactate each at 2.5% and sodium chloride at 5% (prepared w/v in potable water), when compared with solution 'A' (without potassium sorbate). Solution B treatment inhibited Bacillus spp. to minimum and were not detected up to sixth day. It extended the lag phase of all organisms including psychrotrophes (pseudomonads) and reduction of differential counts in sheep and goat meat were noted throughout the refrigerated storage. On sixth day (control) and seventh day (solution "A treated") meat samples developed off odour and discoloration with total viable count (TVC)>10(7) cfu/g. Solution B treated meat samples showed no spoilage at seventh or eighth day, indicating an extended shelf-life of 3 and 2 days when compared with control and solution A treated meat, respectively. PMID:22062386

Nadeem Ahmed, Shaikh; Chattopadhyay, U K; Sherikar, A T; Waskar, V S; Paturkar, A M; Latha, C; Munde, K D; Pathare, N S

2003-03-01

420

Ageing effect in spray pyrolysed B:SnO2 thin films for LPG sensing  

NASA Astrophysics Data System (ADS)

For LPG sensing, boron doped (0.2 to 0.8 wt. %) polycrystalline tin oxide thin films are deposited by spray pyrolysis in the temperature range 325 - 430 °C. Sensor response of 56 % is achieved for 1000 ppm of LPG, at an operating temperature of 350 °C. The effects of ageing under ambient conditions on the sensor response are investigated for a storage period of six years. Ageing increases the film resistance but the gas response is lowered. XRD, SEM, FESEM, FTIR and XPS are utilized for structural, morphological and compositional charaterisations.

Skariah, Benoy; Thomas, Boben

2014-10-01

421

Photoelectrocatrocatalytic hydrolysis of starch by using sprayed ZnO thin films  

NASA Astrophysics Data System (ADS)

Thin films of zinc oxide have been deposited onto glass/FTO substrates at optimized 400 °C by using a chemical spray pyrolysis technique. Deposited films are character photocatalytic activity by using XRD, an SEM, a UV-vis spectrophotometer, and a PEC single-cell reactor. Films are polycrystalline and have a hexagonal (wurtzite) crystal structure with c-axis (002) orientation growth perpendicular to the substrate surface. The observed direct band gap is about 3.22 eV for typical films prepared at 400 °C. The photocatalytic activity of starch with a ZnO photocatalyst has been studied by using a novel photoelectrocatalytic process.

Sapkal, R. T.; Shinde, S. S.; Rajpure, K. Y.; Bhosale, C. H.

2013-05-01

422

Surface morphology dependent TMA sensing response of spray deposited ZnO thin films  

NASA Astrophysics Data System (ADS)

ZnO thin films of different surface morphology were prepared using spray pyrolysis technique by varying precursor salt and solvent. The field emission scanning electron micrograph show the presence of nanofibers, nanoparticles, nanorods and nanosponges like structure owing to the change of precursor solution. The sensing response of ZnO films of different morphology towards trimethylamine (TMA) at room temperature (˜30 °C) were analyzed and reported. The results portray that the nanofibers have moderate sensing abilities towards TMA vapors and out performs the other nanostructures with its response and recovery time being 15 s and 14 s respectively.

Subbulakshmi, K.; Pandeeswari, R.; Jeyaprakash, B. G.

2014-01-01

423

Techno-economics of rice husk pyrolysis, conversion with catalytic treatment to produce liquid fuel  

Microsoft Academic Search

A study was carried out on the techno-economic analysis of the primary pyrolysis process and pyrolysis process with catalytic treatment converting rice husk waste to pyrolysis oil and solid char. The processes considered for detailed analysis were Fluidised Bed Fast Pyrolysis (FBFP) and Fluidised Bed Fast Pyrolysis with Catalytic Treatment (FBFPCT). The assessment was carried out in US$ for three

M. N. Islam; F. N. Ani

2000-01-01

424

Measurements and predictions for nonevaporating sprays in a quiescent environment  

NASA Technical Reports Server (NTRS)

Yule et al. (1982) have conducted a study of vaporizing sprays with the aid of laser techniques. The present investigation has the objective to supplement the measurements performed by Yule et al., by considering the limiting case of a spray in a stagnant environment. Mean and fluctuating velocities of the continuous phase are measured by means of laser Doppler anemometry (LDA) techniques, while Fraunhofer diffraction and slide impaction methods are employed to determine drop sizes. Liquid fluxes in the spray are found by making use of an isokinetic sampling probe. The obtained data are used as a basis for the evaluation of three models of the process, including a locally homogeneous flow (LHF) model, a deterministic separated flow (DSF) model, and a stochastic separated flow (SSF) model. It is found that the LHF and DSF models do not provide very satisfactory predictions for the test sprays, while the SSF model does provide reasonably good predictions of the observed structure.

Solomon, A. S. P.; Shuen, J.-S.; Faeth, G. M.; Zhang, Q.-F.

1983-01-01

425

Catalytic pyrolysis of waste rice husk over mesoporous materials  

NASA Astrophysics Data System (ADS)

Catalytic fast pyrolysis of waste rice husk was carried out using pyrolysis-gas chromatography/mass spectrometry [Py-GC/MS]. Meso-MFI zeolite [Meso-MFI] was used as the catalyst. In addition, a 0.5-wt.% platinum [Pt] was ion-exchanged into Meso-MFI to examine the effect of Pt addition. Using a catalytic upgrading method, the activities of the catalysts were evaluated in terms of product composition and deoxygenation. The structure and acid site characteristics of the catalysts were analyzed by Brunauer-Emmett-Teller surface area measurement and NH3 temperature-programmed desorption analysis. Catalytic upgrading reduced the amount of oxygenates in the product vapor due to the cracking reaction of the catalysts. Levoglucosan, a polymeric oxygenate species, was completely decomposed without being detected. While the amount of heavy phenols was reduced by catalytic upgrading, the amount of light phenols was increased because of the catalytic cracking of heavy phenols into light phenols and aromatics. The amount of aromatics increased remarkably as a result of catalytic upgrading, which is attributed to the strong Brönsted acid sites and the shape selectivity of the Meso-MFI catalyst. The addition of Pt made the Meso-MFI catalyst even more active in deoxygenation and in the production of aromatics.

Jeon, Mi-Jin; Kim, Seung-Soo; Jeon, Jong-Ki; Park, Sung Hoon; Kim, Ji Man; Sohn, Jung Min; Lee, See-Hoon; Park, Young-Kwon

2012-01-01

426

Electrocatalytic upgrading of biomass pyrolysis oils to chemical and fuel  

NASA Astrophysics Data System (ADS)

The present project's aim is to liquefy biomass through fast pyrolysis and then upgrade the resulting "bio-oil" to renewable fuels and chemicals by intensifying its energy content using electricity. This choice reflects three points: (a) Liquid hydrocarbons are and will long be the most practical fuels and chemical feedstocks because of their energy density (both mass and volume basis), their stability and relative ease of handling, and the well-established infrastructure for their processing, distribution and use; (b) In the U.S., the total carbon content of annually harvestable, non-food biomass is significantly less than that in a year's petroleum usage, so retention of plant-captured carbon is a priority; and (c) Modern technologies for conversion of sunlight into usable energy forms---specifically, electrical power---are already an order of magnitude more efficient than plants are at storing solar energy in chemical form. Biomass fast pyrolysis (BFP) generates flammable gases, char, and "bio-oil", a viscous, corrosive, and highly oxygenated liquid consisting of large amounts of acetic acid and water together with hundreds of other organic compounds. With essentially the same energy density as biomass and a tendency to polymerize, this material cannot practically be stored or transported long distances. It must be upgraded by dehydration, deoxygenation, and hydrogenation to make it both chemically and energetically compatible with modern vehicles and fuels. Thus, this project seeks to develop low cost, general, scalable, robust electrocatalytic methods for reduction of bio-oil into fuels and chemicals.

Lam, Chun Ho

427

Catalytic pyrolysis of waste rice husk over mesoporous materials  

PubMed Central

Catalytic fast pyrolysis of waste rice husk was carried out using pyrolysis-gas chromatography/mass spectrometry [Py-GC/MS]. Meso-MFI zeolite [Meso-MFI] was used as the catalyst. In addition, a 0.5-wt.% platinum [Pt] was ion-exchanged into Meso-MFI to examine the effect of Pt addition. Using a catalytic upgrading method, the activities of the catalysts were evaluated in terms of product composition and deoxygenation. The structure and acid site characteristics of the catalysts were analyzed by Brunauer-Emmett-Teller surface area measurement and NH3 temperature-programmed desorption analysis. Catalytic upgrading reduced the amount of oxygenates in the product vapor due to the cracking reaction of the catalysts. Levoglucosan, a polymeric oxygenate species, was completely decomposed without being detected. While the amount of heavy phenols was reduced by catalytic upgrading, the amount of light phenols was increased because of the catalytic cracking of heavy phenols into light phenols and aromatics. The amount of aromatics increased remarkably as a result of catalytic upgrading, which is attributed to the strong Brönsted acid sites and the shape selectivity of the Meso-MFI catalyst. The addition of Pt made the Meso-MFI catalyst even more active in deoxygenation and in the production of aromatics. PMID:22221540

2012-01-01

428

INEL Spray-forming Research  

NASA Technical Reports Server (NTRS)

Spray forming is a near-net-shape fabrication technology in which a spray of finely atomized liquid droplets is deposited onto a suitably shaped substrate or mold to produce a coherent solid. The technology offers unique opportunities for simplifying materials processing without sacrificing, and oftentimes substantially improving, product quality. Spray forming can be performed with a wide range of metals and nonmetals, and offers property improvements resulting from rapid solidification (e.g., refined microstructures, extended solid solubilities and reduced segregation). Economic benefits result from process simplification and the elimination of unit operations. Researchers at the Idaho National Engineering Laboratory (INEL) are developing spray-forming technology for producing near-net-shape solids and coatings of a variety of metals, polymers, and composite materials. Results from several spray forming programs are presented to illustrate the range of capabilities of the technique as well as the accompanying technical and economic benefits. Low-carbon steel strip greater than 0.75 mm thick and polymer membranes for gas/gas and liquid/liquid separations that were spray formed are discussed; recent advances in spray forming molds, dies, and other tooling using low-melting-point metals are described.

Mchugh, Kevin M.; Key, James F.

1993-01-01

429

The plasma spray forming of Astroloy  

SciTech Connect

The work described in this paper is part of a general study concerning new methods for the manufacturing of turbo-engine and turbo-pump parts. The presented results concern a VPS formed nickel-based alloy, the Astroloy (AFNOR NK17CDAT). In a first time are presented the metallographic microstructures of the as-sprayed and heat-treated deposits and secondly spray formed test pieces developed in order to characterize the mechanical properties of such materials. Then, the mechanical properties, including the tensile properties, the Low Cycle Fatigue life-time, the creep life-time and the adherence are presented. The results have been compared with those of sintered parts and the measured performances of such plasma formed free-standing shapes were found to be equivalent or superior. Such good results are attributed to the very fine grained, recrystallized microstructures and to the very low level of macroporosities in the deposit.

Montavon, G.; Roussel, E.; Coddet, C. [LERMPS-Institut Polytechnique de Sevenans, Belfort (France); Cornu, D.; Monicault, J.M. De [Societe Europeenne de Propulsion, Vernon (France); Fauvet, E.; Huchin, J.P. [Sochata, Chatellerault (France); Garcia, J.C.; Pellerin, F. [Turbomeca, Tarnos (France)

1994-12-31

430

Enhanced photocatalytic activity of sprayed Au doped ferric oxide thin films for salicylic acid degradation in aqueous medium.  

PubMed

Various doping percentage of Au were successfully introduced into the Fe2O3 photocatalysts via a spray pyrolysis method different. The effect of Au doping on photoelectrochemical, structural, optical and morphological properties of these deposited thin films is studied. The PEC characterization shows that, the photocurrent increases gradually with increasing Au content initially up to 2at.% indicating the maximum values of short circuit current (Isc) and open circuit voltage (Voc) are (Isc=90?A and Voc=220.5mV) and then decreases after exceeding the optimal Au doping content. Therefore, the photocurrent of Au doped Fe2O3 photocatalysts can be adjusted by the Au content. Deposited films are polycrystalline with a rhombohedral crystal structure having (104) preferred orientation. SEM and AFM images show deposited thin films are compact and uniform. The photocatalytic activities of the Fe2O3 and Au:Fe2O3 photocatalyst were evaluated by photoelectrocatalytic degradation of salicylic acid under sunlight irradiation. The results show that the Au:Fe2O3 thin film photocatalyst exhibited about 45% more degradation of pollutants than the pure Fe2O3. Thus, in Au doped Fe2O3 photocatalysts, the interaction between Au and Fe2O3 reduces the recombination of photogenerated charge carriers and improve the photocatalytic activity. PMID:25496876

Mahadik, M A; Shinde, S S; Kumbhar, S S; Pathan, H M; Rajpure, K Y; Bhosale, C H

2015-01-01

431

Physical and photo-electrochemical characterizations of ZnO thin films deposited by ultrasonic spray method: Application to HCrO4- photoreduction  

NASA Astrophysics Data System (ADS)

ZnO thin films, prepared by ultrasonic spray onto glass substrate, crystallize in the wurtzite structure. The XRD pattern shows preferential orientation along the [0 0 2] direction. The films deposited at 350 °C consist of 60 nm crystallites with an average thickness of ?150 nm and SEM images show rough surface areas. The gap increases with increasing the temperature of the substrate and a value of 3.25 eV is obtained for films deposited at 350 °C. ZnO is nominally non-stochiometric and exhibits n-type conduction because of the native defects such as oxygen vacancies (VO) and/or interstitial zinc atom (Zni) which act as donor shallows. The conductivity is thermally activated and obeys to an exponential type law with activation energy of 57 meV and an electron mobility of 7 cm2 V-1 s-1. The capacitance-voltage (C-2 V) measurement in acid electrolyte (pH ? 3) shows a linear behavior with a positive slope, characteristic of n-type conduction. A flat band potential of -0.70 VSCE and a donors density of 5.30 × 1016 cm-3 are determined. The Nyquist plot exhibits two semicircles attributed to a capacitive behavior with a low density of surface states within the gap region. The centre is localized below the real axis with a depletion angle of 16° ascribed to a constant phase element (CPE) due to the roughness of the film. The energy band diagram assesses the potentiality of ZnO films for the photo-electrochemical conversion. As application, 94% of chromate (3.8 × 10-4 M) is reduced after 6 h under sunlight (AM 1) with a quantum yield of 0.06% and the oxidation follows a first order kinetic.

Zebbar, N.; Trari, M.; Doulache, M.; Boughelout, A.; Chabane, L.

2014-02-01

432

The Durability of Adhesively-Bonded Titanium: Performance of Plasma-Sprayed Polymeric Coating Pretreatments  

Microsoft Academic Search

Non-solution and electrochemical treatments in preparation for adhesive bonding of titanium have been studied. Polymeric materials, LaRC TPI-2000, LaRC PETI-5, and Aurum polyimides were deposited onto titanium-6Al-4V surfaces via plasma spraying. The plasma-sprayed surfaces were characterized using infrared, solid state NMR, and surface-sensitive analytical methods. The chemical nature of plasma-sprayed polymers is equivalent to that for powdered materials. The durability

J. G. Dillard; F. R. Jackson; B. L. Holmes; L. Aartun; H. Parvatareddy; D. A. Dillard; R. Zatorski

1998-01-01

433

The hot erosion behavior of HVOF chromium carbide-metal cermet coatings sprayed with different powders  

Microsoft Academic Search

The high velocity oxygen fuel (HVOF) sprayed chromium carbide-metal cermet coatings have shown some attractive behavior, which makes them superior to arc-sprayed iron base coatings in preventing erosion. While their hot erosion behavior and its dependence on carbide\\/metal matrix proportion have been investigated, the detail study of the hot erosion behavior being dependent on the spraying methods and the starting

Bu Qian Wang; Zheng Rong Shui

2002-01-01

434

Touch spray mass spectrometry for in situ analysis of complex samples.  

PubMed

Touch spray, a spray-based ambient in situ ionization method, uses a small probe, e.g. a teasing needle to pick up sample and the application of voltage and solvent to cause field-induced droplet emission. Compounds extracted from the microsample are incorporated into the sprayed micro droplets. Performance tests include disease state of tissue, microorganism identification, and therapeutic drug quantitation. Chemical derivatization is performed simultaneously with ionization. PMID:24756256

Kerian, Kevin S; Jarmusch, Alan K; Cooks, R Graham

2014-06-01

435

Gas Dynamic Spray Technology Demonstration  

NASA Technical Reports Server (NTRS)

Zinc primer systems are currently used across NASA and AFSPC for corrosion protection of steel. AFSPC and NASA have approved the use of Thermal Spray Coatings (TSCs) as an environmentally preferable alternative. TSCs are approved in NASA-STD-5008 and AFSPC and KSC is currently looking for additional applications in which TSC can be used. Gas Dynamic Spray (GDS, also known as Cold Spray) is being evaluated as a means of repairing TSCs and for areas such as corners and edges where TSCs do not work as well. Other applications could include spot repair/maintenance of steel on structures, facilities, and ground support equipment.

Burford, Pattie Lewis

2011-01-01

436

Effects of torrefaction and densification on switchgrass pyrolysis products.  

PubMed

The pyrolysis behaviors of four types of pretreated switchgrass (torrefied at 230 and 270°C, densification, and torrefaction at 270°C followed by densification) were studied at three temperatures (500, 600, 700°C) using a pyroprobe attached to a gas chromatogram mass spectroscopy (Py-GC/MS). The torrefaction of switchgrass improved its oxygen to carbon ratio and energy content. Contents of anhydrous sugars and phenols in pyrolysis products of torrefied switchgrass were higher than those in pyrolysis products of raw switchgrass. As the torrefaction temperature increased from 230 to 270°C, the contents of anhydrous sugars and phenols in pyrolysis products increased whereas content of guaiacols decreased. High pyrolysis temperature (600 and 700°C as compared to 500°C) enhanced decomposition of lignin and anhydrous sugars, leading to increase in phenols, aromatics and furans. Densification enhanced depolymerization of cellulose and hemicellulose during pyrolysis. PMID:25463807

Yang, Zixu; Sarkar, Madhura; Kumar, Ajay; Tumuluru, Jaya Shankar; Huhnke, Raymond L

2014-12-01

437

Pyrolysis of Spent Ion Exchange Resins - 12210  

SciTech Connect

Organic ion exchangers (IEX) play a major and increasing role in the reactor coolant and other water purification processes. During their operation time they receive significant amounts of radioactivity, making their disposal, together with their organic nature, as medium active waste challenging. Processes applied so far do not eliminate the organic matter, which is unwanted in disposal facilities, or, if high temperatures are applied, raise problems with volatile radionuclides. NUKEM Technologies offers their well introduces process for the destruction of spent solvent (TBP), the pebble bed pyrolysis, now for the treatment of spent IEX (and other problematic waste), with the following benefits: the pyrolysis product is free of organic matter, and the operation temperature with approx. 500 deg. C keeps Cs radionuclides completely in the solid residue. (authors)

Braehler, Georg; Slametschka, Rainer [NUKEM Technologies GmbH (Germany)

2012-07-01

438

Char reactions during kraft black liquor pyrolysis  

SciTech Connect

The pyrolysis characteristics of dried black liquor particles were investigated at high heating rates in a laminar entrained-flow reactor at temperatures of 600-1100{degrees}C. Primary pyrolysis of the organic fraction occurred very rapidly, in less 0.5 seconds. Char yields at the end or volatiles evolution were 58-72%. The decreased with increasing reactor temperature to 900{degrees}C but remained constant at higher temperatures. 35-65% of the fuel nitrogen was volatilized, nearly all in less than 0.5 s. Relatively little fuel nitrogen was evolved from the char. Significant alkali metal chloride volatization from the char occurred at all temperatures, while additional sodium volatilization became important above 900{degrees}C. Reduction of sulfur species in the char increased rapidly with increasing temperature. A temperature-dependent delay time in the onset of Na{sub 2}S formation was observed.

Frederick, W.J.; Sricharoenchaikul, V.; Reis, V.V. [Oregon State Univ., Corvallis, OR (United States)

1995-12-01

439

Modifications Of A Commercial Spray Gun  

NASA Technical Reports Server (NTRS)

Commercial spray gun modified to increase spray rate and make sprayed coats more nearly uniform. Consists of gun head and pneumatic actuator. Actuator opens valves for two chemical components, called "A" and "B," that react to produce foam. Components flow through orifices, into mixing chamber in head. Mixture then flows through control orifice to spray tip. New spray tip tapered to reduce area available for accumulation of foam and makes tip easier to clean.

Allen, Peter B.

1993-01-01

440

Characterization of fully functional spray-on antibody thin films  

NASA Astrophysics Data System (ADS)

The authors recently demonstrated that fully functional Escherichia coli O157:H7 antibody thin films can be prepared using a simple pneumatic nebulizer on glass surface [1]. This paper focuses on the investigation of the morphology and physical properties of these films with the aim to better understand their performance. A series of E. coli O157:H7 antibody spray-on thin films were investigated by ellipsometry, X-ray photoelectron spectroscopy (XPS), immunoassays, attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), fluorescence microscopy, atomic force microscope (AFM) and contact angle analysis. These data were compared to measurements on films prepared with the biotin-avidin covalent bonding scheme. The investigation showed that films created by a 2 min pneumatic spray deposition time can capture antigens similar as the avidin-biotin wet-chemical method. The results also suggests that an influential factor for the comparable capture cell ability between sprayed and covalent films is an increased antibody surface coverage for the sprayed films (non-equilibrium technique), which compensates for the lack of its antibody orientation. There was no significant antibody denaturation detected on any of the sprayed films. Both techniques led to the formation of cluster-aggregates, a factor that seems unavoidable due to the natural tendency of protein to cluster. The avidin-biotin bridge films generally had a higher roughness, which manifested itself in a higher wettability compared to the sprayed films.

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

2014-02-01

441

Studies on fuel spray characteristics in high-pressure environment  

NASA Technical Reports Server (NTRS)

The present study deals with several issues involving the improvement of physical submodels and the computational efficiency in modeling dense fuel sprays. To improve the computational efficiency, a parcel PDF approach is implemented which can account for turbulent dispersion within each computational parcel. The advantage of a parcel PDF tracking method is to reduce the number of computational parcels representing the spray dynamics as well as to obtain grid-independent solutions for two-phase flows. To account for the dense spray effects, an existing drop collision and coalescence model, two breakup models, and a Reitz's wave instability model were used. These models were incorporated into a state-of-the-art multiphase all-speed transient flow solution procedure. Comparative performance for two breakup models as well as the turbulence modulation effects are also studied. Validation cases include the nonevaporating and evaporating solid-cone dense sprays. The predictions show a reasonably good agreement with available experimental results in terms of spray penetration, drop sizes, gas and drop mean velocities, and gas and drop rms velocities. The numerical results indicate that th