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Sample records for spray pyrolysis method

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

    SciTech Connect

    Ramadhani, Muhammad F. Pasaribu, Maruli A. H. Yuliarto, Brian Nugraha

    2014-02-24

    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.

  2. Method to synthesize and produce thin films by spray pyrolysis

    DOEpatents

    Squillante, Michael R.

    1982-06-22

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

  3. Method to synthesize and produce thin films by spray pyrolysis

    DOEpatents

    Turcotte, Richard L.

    1982-07-06

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

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

    SciTech Connect

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

    2014-10-15

    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.

  5. Hydrogen-free spray pyrolysis chemical vapor deposition method for the carbon nanotube growth: Parametric studies

    NASA Astrophysics Data System (ADS)

    Ionescu, Mihnea Ioan; Zhang, Yong; Li, Ruying; Sun, Xueliang; Abou-Rachid, Hakima; Lussier, Louis-Simon

    2011-05-01

    Spray pyrolysis chemical vapor deposition (CVD) in the absence of hydrogen at low carrier gas flow rates has been used for the growth of carbon nanotubes (CNTs). A parametric study of the carbon nanotube growth has been conducted by optimizing various parameters such as temperature, injection speed, precursor volume, and catalyst concentration. Experimental observations and characterizations reveal that the growth rate, size and quality of the carbon nanotubes are significantly dependent on the reaction parameters. Scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy techniques were employed to characterize the morphology, structure and crystallinity of the carbon nanotubes. The synthesis process can be applied to both semiconducting silicon wafer and conducting substrates such as carbon microfibers and stainless steel plates. This approach promises great potential in building various nanodevices with different electron conducting requirements. In addition, the absence of hydrogen as a carrier gas and the relatively low synthesis temperature (typically 750 °C) qualify the spray pyrolysis CVD method as a safe and easy way to scale up the CNT growth, which is applicable in industrial production.

  6. A Spray Pyrolysis Method to Grow Carbon Nanotubes on Carbon Fibres, Steel and Ceramic Bricks.

    PubMed

    Vilatela, Juan J; Rabanal, M E; Cervantes-Sodi, Felipe; García-Ruiz, Máximo; Jiménez-Rodríguez, José A; Reiband, Gerd; Terrones, Mauricio

    2015-04-01

    We demonstrate a spray pyrolysis method to grow carbon nanotubes (CNTs) with high degree of crystallinity, aspect ratio and degree of alignment on a variety of different substrates, such as conventional steel, carbon fibres (CF) and ceramics. The process consists in the chemical vapour deposition of both a thin SiO2 layer and CNTs that subsequently grow on this thin layer. After CNT growth, increases in specific surface by factors of 1000 and 30 for the steel and CF samples, respectively, are observed. CNTs growth on ceramic surfaces results in a surface resistance of 37.5 Ohm/sq. When using conventional steel as a rector tube, we observed CNTs growth rates of 0.6 g/min. Details of nanotube morphology and the growth mechanism are discussed. Since the method discussed here is highly versatile, it opens up a wide variety of applications in which specific substrates could be used in combination with CNTs.

  7. Synthesis of kerosene based nanocarbons by a nebulized spray pyrolysis method

    NASA Astrophysics Data System (ADS)

    Widjaja, Ongky; Arie, Arenst Andreas; Halim, Martin; Lee, Joong Kee

    2016-04-01

    In this work, kerosene oil based nanocarbons were synthesized by a nebulized spray pyrolysis method. This method was conducted at temperature of 700°C under a nitrogen inert atmospheric condition. Activated carbon and ferrocene were used as substrate and catalyst, respectively. Initially, ferrocene was dissolved in the oil with fixed concentration of 0.02 g/ml. The pyrolysis reaction was carried out by varying the operating time of 15, 30 and 45 minutes. The main aim of this work was to investigate the effect of varying the operation time on the morphology and structural characteristics of as-prepared carbon products. The morphology and structural characteristics of synthesized nanocarbons were examined by Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), and Raman Spectroscopy, respectively. SEM and TEM observations showed that nano carbons were formed as agglomerated carbon nanospheres (CNSs) and graphene for all variation of operating time. Furthermore, it was observed that the size of agglomerated CNSs was proportional with the operating time from 15 to 45 minutes. Raman analysis showed that the ratio between graphite like and disorder carbon structure (IG/ID)of carbon samples increased from operating time of 15 to 30 minutes, however the ratio decreased from 30 minutes to 45 minutes.

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

    NASA Astrophysics Data System (ADS)

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

    2008-01-01

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

  9. Spray pyrolysis of CZTS nanoplatelets.

    PubMed

    Exarhos, S; Bozhilov, K N; Mangolini, L

    2014-10-01

    We demonstrate that copper-zinc-tin-sulphide nanoplatelets can be directly grown onto a molybdenum-coated substrate using spray pyrolysis starting from a mixture of metal thiocarbamates precursors. The structure and phase purity of the nanoplatelets is discussed in detail. PMID:25119262

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

    NASA Astrophysics Data System (ADS)

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

    2013-08-01

    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 Ω/sq and a good transparency of 70.8%. The nanorods have a higher surface area than the conventionally used thin films.

  11. Development of Ag/WO3/ITO thin film memristor using spray pyrolysis method

    NASA Astrophysics Data System (ADS)

    Dongale, T. D.; Mohite, S. V.; Bagade, A. A.; Gaikwad, P. K.; Patil, P. S.; Kamat, R. K.; Rajpure, K. Y.

    2015-11-01

    The unique nonlinear relationship between charge and magnetic flux along with the pinched hysteresis loop in I- V plane provide memory with resistance combinations of attribute to Memristor which lead to their novel applications in non volatile memory, nonlinear dynamics, analog computations and neuromorphic biological systems etc. The present paper reports development of Ag/WO3/ITO thin film memristor device using spray pyrolysis method. The structural, morphological and electrical properties of the thin film memristor device are further characterized using x-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and semiconductor device analyzer. The memristor is simulated using linear dopent drift model to ascertain the theoretical and experimental conformations. For the simulation purpose, the width of doped region (w) limited to the interval [0, D] is considered as a state variable along with the window function characterized by the equation f ( x) = w (1 - w). The reported memristor device exhibits the symmetric pinched hysteresis loop in I- V plane within the low operating voltage (±1 V). [Figure not available: see fulltext.

  12. Properties of cadmium-doped tin oxide thin films prepared by spray pyrolysis method

    NASA Astrophysics Data System (ADS)

    Choudhury, M. G. M.; Hossain, M. Mortuza; Rahman, M. Mozibur; Hakim, M. O.; Khan, M. K. R.

    2003-10-01

    Cadmium doped Tin Oxide Thin Films have been prepared by Spray Pyrolysis Method on glass substrates at 350°C. Structural, electrical and optical properties have been measured. From XRD it is found that films deposited are crystalline in nature with tetragonal structure having lattice constant a=b=3.86 A° and c=5.62A°. Hall effect measurements show that films prepared are of n-type and the carrier concentration (~1018 cm-3) and room temperature conductivity decreases with the increases in cadmium concentration in the films. Activation energy has been calculated from conductivity measurements and it was found that conduction within the temperature range we have measured is due to hoping of carriers through the spectrum of localized states. Band gap of the un-doped films calculated from transmission spectrum is about 3.1 eV and the value decrease slightly with the addition of cadmium. The refractive index, extinction coefficient, real and imaginary parts of the dielectric constant have been calculated from the optical spectra. The refractive index decreases with photon energy and also decreases slightly with cadmium concentration while extinction coefficient increases with photon energy.

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

    SciTech Connect

    Chen, J.-C.; Chang, C.-L.; Hsu, C.-S.; Hwang, B.-H. . E-mail: zorro@mail.nsysu.edu.tw

    2007-09-04

    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.

  14. Structural and physical properties of boron doped ZnO films prepared by chemical spray pyrolysis method

    NASA Astrophysics Data System (ADS)

    Kerli, S.; Alver, U.; Tanriverdi, A.; Avar, B.

    2015-11-01

    In this work, ZnO and boron doped ZnO (ZnO:B) thin films were produced by chemical spray pyrolysis method. ZnO and ZnO:B films were obtained onto glass substrates at 450°C by spray pyrolysis method and the physical properties of those films were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible spectrometer (UV) and four probe technique. XRD measurements show that all films have hexagonal wurtzite structure and all films grow preferentially along (002) direction. Morphologies of the films were examined by using a scanning electron microscopy and it was observed that almost all films were quite intense with a regular structure. Optical measurements showed that the band gap energies of the films increased with boron concentrations. The resistances of the B-doped ZnO films were measured by four probe method and resistances of films initially decreased to its minimum 1 at% boron doping and then it increased again with increasing B concentration. It was also observed that that boron doping increased the activation energies of the films.

  15. Photocatalytic Activities of Copper Doped Cadmium Sulfide Microspheres Prepared by a Facile Ultrasonic Spray-Pyrolysis Method.

    PubMed

    Su, Jinzhan; Zhang, Tao; Li, Yufeng; Chen, Yubin; Liu, Maochang

    2016-01-01

    Ultrasonic spray pyrolysis is a superior method for preparing and synthesizing spherical particles of metal oxide or sulfide semiconductors. Cadmium sulfide (CdS) photocatalysts with different sizes and doped-CdS with different dopants and doping levels have been synthesized to study their properties of photocatalytic hydrogen production from water. The CdS photocatalysts were characterized with scanning electron microscopy (SEM), X-ray fluorescence-spectrometry (XRF), UV-Vis absorption spectra and X-ray diffraction (XRD) to study their morphological and optical properties. The sizes of the prepared CdS particles were found to be proportional to the concentration of the metal nitrates in the solution. The CdS photocatalyst with smaller size showed a better photocatalytic activity. In addition, Cu doped CdS were also deposited and their photocatalytic activities were also investigated. Decreased bandgaps of CdS synthesized with this method were found and could be due to high density surface defects originated from Cd vacancies. Incorporating the Cu elements increased the bandgap by taking the position of Cd vacancies and reducing the surface defect states. The optimal Cu-doped level was found to be 0.5 mol % toward hydrogen evolution from aqueous media in the presence of sacrificial electron donors (Na₂S and Na₂SO₃) at a pH of 13.2. This study demonstrated that ultrasonic spray pyrolysis is a feasible approach for large-scale photocatalyst synthesis and corresponding doping modification. PMID:27314320

  16. Using Modified Spray Pyrolysis-Calcination Method and Their Magnetic Properties

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

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

  17. The effect of substrate temperature on the structure of tin oxide thin films obtained by spray pyrolysis method

    SciTech Connect

    Rozati, S.M. . E-mail: smrozati@guilan.ac.ir

    2006-09-15

    Undoped SnO{sub 2} thin films were prepared on glass substrates by spray pyrolysis technique. The variation in the structural properties with a variation in the substrate temperature was investigated by means of X-ray diffraction (XRD). In this paper we employed the XRD technique to achieve the impression of the crystalline planes and also the possible orientation of crystallites in the films prepared at different substrate temperature ranging from 250 to 575 deg. C.

  18. Producing Quantum Dots by Spray Pyrolysis

    NASA Technical Reports Server (NTRS)

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

    2006-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

    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 Ω·cm, which is beneficial for solar cells, were achieved.

  20. Vertically aligned carbon nanotubes from natural precursors by spray pyrolysis method and their field electron emission properties

    NASA Astrophysics Data System (ADS)

    Ghosh, Pradip; Soga, T.; Tanemura, M.; Zamri, M.; Jimbo, T.; Katoh, R.; Sumiyama, K.

    2009-01-01

    Vertically aligned carbon nanotubes have been synthesized from botanical hydrocarbons: Turpentine oil and Eucalyptus oil on Si(100) substrate using Fe catalyst by simple spray pyrolysis method at 700°C and at atmospheric pressure. The as-grown carbon nanotubes were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), thermogravimetric analysis (TGA), differential thermal analysis (DTA), and Raman spectroscopy. It was observed that nanotubes grown from turpentine oil have better degree of graphitization and field emission performance than eucalyptus oil grown carbon nanotubes. The turpentine oil and eucalyptus oil grown carbon nanotubes indicated that the turn-on field of about 1.7 and 1.93 V/μm, respectively, at 10 μA/cm2. The threshold field was observed to be about 2.13 and 2.9 V/μm at 1 mA/cm2 of nanotubes grown from turpentine oil and eucalyptus oil respectively. Moreover, turpentine oil grown carbon nanotubes show higher current density in relative to eucalyptus oil grown carbon nanotubes. The maximum current density of 15.3 mA/cm2 was obtained for ˜3 V/μm corresponding to the nanotubes grown from turpentine oil. The improved field emission performance was attributed to the enhanced crystallinity, fewer defects, and greater length of turpentine oil grown carbon nanotubes.

  1. Mössbauer studies of nanocrystalline ZnFe2O4 particles prepared by spray pyrolysis method

    NASA Astrophysics Data System (ADS)

    Kurian, Jessyamma; John, Subin P.; M, Jacob Mathew; Reddy, V. R.; E, Abraham K.; Prasad, V. S.

    2015-02-01

    This paper reports the synthesis and characterization of nanoparticles of Zn Fe2O4 by spray pyrolysis method. XRD studies indicates that the particle formed are ultra fine (20 nm) associated with strain. The particle size is confirmed by TEM analysis. The room temperature Mossbauer spectrum shows only a doublet which could be indicative of either paramaganetic or superparamagnetic phase. The value of isomer shift is in the range 0.34±0.01 mm/s while quadruple splitting is in the range 0.48±0.01 mm/s. A series of low temperature studies has been performed and the spectra obtained at 20 K and 5K show the presence of two well resolved sextets, which are attributed to the Fe3+ ion in the tetrahedral and octahedral sites of the spinel structure. The application of external magnetic field yields a better fitting resolution of the sub spectra between A and B sites. The temperature dependant and in-field measurements yielded valuable insights about magnetic phase (superparamagnetic), local cation distribution among A sites and B sites, inversion parameter (δ =0.74), canted spin alignment (ψA = 29.58, ψB= 48.46) and the blocking temperature (TB= 50 K).

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

    NASA Astrophysics Data System (ADS)

    Kırcı, Burak; Ebin, Burçak; Gürmen, Sebahattin

    2013-12-01

    The ultrasonic spray pyrolysis (USP) method has been used to prepare submicron hematite (α-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.

  3. Spray pyrolysis as a method for preparing PbO coatings amenable to use in lead-acid batteries

    NASA Astrophysics Data System (ADS)

    Cruz, M.; Hernán, L.; Morales, J.; Sánchez, L.

    Lead(II) oxide thin films were prepared by spray pyrolysis of aqueous solutions of Pb(CH 3COO) 2·2H 2O and deposited onto a lead substrate. A homogeneous coating was obtained at 260 °C that consisted of well-crystallized α-PbO. Following soaking and curing, the oxide became a phase mixture the main component of which was PbO·PbSO 4. The electroformation of the cured plate produces dense agglomerates of small β-PbO 2 particles accompanied by unreacted α-PbO. Preliminary electrochemical tests of the cell revealed a progressive decrease in polarization during charging in the first few cycles probably associated to improved adherence of active particles to the substrate. The cell was found to maintain a discharge capacity of ca. 100 A h/kg (40% of the theoretical value) upon extensive cycling.

  4. Magnetic-luminescent spherical particles synthesized by ultrasonic spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Michel, Norma L.; Flores, Dora L.; Hirata, Gustavo A.

    2015-07-01

    The combination of magnetic and luminescent properties in a single particle system, opens-up a wide range of potential applications in biotechnology and biomedicine. In this work, we performed the synthesis of magnetic-luminescent Gd2O3:Eu3+@Fe2O3 particles by ultrasonic spray pyrolysis performed in a tubular furnace. In order to achieve the composite formation, commercial superparamagnetic Fe3O4 nanoparticles were coated with a luminescent Eu3+-doped Gd2O3 shell in a low-cost one-step process. The spray pyrolysis method yields deagglomerated spherical shape magneto/luminescent particles. The photoluminescence spectra under UV excitation (λExc = 265 nm) of the magnetic Gd2O3:Eu3+@Fe2O3 compound showed the characteristic red emission of Eu3+ (λEm = 612 nm). This magneto/luminescent system will find applications in biomedicine and biotechnology.

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  6. Ternary Porous Sulfur/Dual-Carbon Architectures for Lithium/Sulfur Batteries Obtained Continuously and on a Large Scale via an Industry-Oriented Spray-Pyrolysis/Sublimation Method.

    PubMed

    Liang, Xin; Kaiser, Mohammad Rejaul; Konstantinov, Konstantin; Tandiono, Richard; Wang, Zhaoxiang; Chen, Chunhua; Liu, Hua-Kun; Dou, Shi-Xue; Wang, Jiazhao

    2016-09-28

    Ternary composites with porous sulfur/dual-carbon architectures have been synthesized by a single-step spray-pyrolysis/sublimation technique, which is an industry-oriented method that features continuous fabrication of products with highly developed porous structures without the need for any further treatments. A double suspension of commercial sulfur and carbon scaffolding particles was dispersed in ethanol/water solution and sprayed at 180 °C using a spray pyrolysis system. In the resultant composites, the sulfur particles were subjected to an ultrashort sublimation process, leading to the development of a highly porous surface, and were meanwhile coated with amorphous carbon, obtained through the pyrolysis of the ethanol, which acts as an adhesive interface to bind together the porous sulfur with the scaffolding carbon particles, to form a ternary composite architecture. This material has an effective conducting-carbon/sulfur-based matrix and interconnected open pores to reduce the diffusion paths of lithium ions, buffer the sulfur volumetric expansion, and absorb electrolyte and polysulfides. Because of the unique chemistry and the structure, the composites show stable cycling performance for 200 cycles and good rate capability of 520 mAh g(-1) at 2 C. This advanced spray-pyrolysis/sublimation method is easy to scale up and shows great potential for commercialization of lithium/sulfur batteries.

  7. Ternary Porous Sulfur/Dual-Carbon Architectures for Lithium/Sulfur Batteries Obtained Continuously and on a Large Scale via an Industry-Oriented Spray-Pyrolysis/Sublimation Method.

    PubMed

    Liang, Xin; Kaiser, Mohammad Rejaul; Konstantinov, Konstantin; Tandiono, Richard; Wang, Zhaoxiang; Chen, Chunhua; Liu, Hua-Kun; Dou, Shi-Xue; Wang, Jiazhao

    2016-09-28

    Ternary composites with porous sulfur/dual-carbon architectures have been synthesized by a single-step spray-pyrolysis/sublimation technique, which is an industry-oriented method that features continuous fabrication of products with highly developed porous structures without the need for any further treatments. A double suspension of commercial sulfur and carbon scaffolding particles was dispersed in ethanol/water solution and sprayed at 180 °C using a spray pyrolysis system. In the resultant composites, the sulfur particles were subjected to an ultrashort sublimation process, leading to the development of a highly porous surface, and were meanwhile coated with amorphous carbon, obtained through the pyrolysis of the ethanol, which acts as an adhesive interface to bind together the porous sulfur with the scaffolding carbon particles, to form a ternary composite architecture. This material has an effective conducting-carbon/sulfur-based matrix and interconnected open pores to reduce the diffusion paths of lithium ions, buffer the sulfur volumetric expansion, and absorb electrolyte and polysulfides. Because of the unique chemistry and the structure, the composites show stable cycling performance for 200 cycles and good rate capability of 520 mAh g(-1) at 2 C. This advanced spray-pyrolysis/sublimation method is easy to scale up and shows great potential for commercialization of lithium/sulfur batteries. PMID:27529563

  8. Synthesis of Carbon Nanotubes by CVD and Spray Pyrolysis and Their Characterization by Scattering Techniques

    NASA Astrophysics Data System (ADS)

    Bahadur, J.; Prakash, J.; Sen, D.; Mazumder, S.; Sathiyamoorthy, D.

    2011-07-01

    Carbon nanotubes have been synthesized by catalytic chemical vapor deposition and spray pyrolysis methods. Synthesized nanotubes were characterized by Small-angle neutron scattering, X-ray diffraction and Raman spectroscopy. Scattering data reveals the aggregated nature of nanotubes, the average diameter and average length have also been estimated. It has been observed that the nanotubes, synthesized by spray pyrolysis methods, possess fewer defects in their graphitic nature of wall. The X-ray diffraction data reveals that the nanotubes possess metal oxide impurities.

  9. Photoluminescence of spray pyrolysis deposited ZnO nanorods

    PubMed Central

    2011-01-01

    Photoluminescence of highly structured ZnO layers comprising well-shaped hexagonal rods is presented. The ZnO rods (length 500-1,000 nm, diameter 100-300 nm) were grown in air onto a preheated soda-lime glass (SGL) or ITO/SGL substrate by low-cost chemical spray pyrolysis method using zinc chloride precursor solutions and growth temperatures in the range of 450-550°C. We report the effect of the variation in deposition parameters (substrate type, growth temperature, spray rate, solvent type) on the photoluminescence properties of the spray-deposited ZnO nanorods. A dominant near band edge (NBE) emission is observed at 300 K and at 10 K. High-resolution photoluminescence measurements at 10 K reveal fine structure of the NBE band with the dominant peaks related to the bound exciton transitions. It is found that all studied technological parameters affect the excitonic photoluminescence in ZnO nanorods. PACS: 78.55.Et, 81.15.Rs, 61.46.Km PMID:21711895

  10. An easy and innovative method based on spray-pyrolysis deposition to obtain high efficiency cathodes for Solid Oxide Fuel Cells

    NASA Astrophysics Data System (ADS)

    dos Santos-Gómez, L.; Porras-Vázquez, J. M.; Martín, F.; Ramos-Barrado, J. R.; Losilla, E. R.; Marrero-López, D.

    2016-07-01

    A novel electrode preparation method based on the spray-pyrolysis deposition of metal nitrate solutions onto a porous electrolyte scaffold is proposed. This method has been proved with different cathode materials, usually used in Solid Oxide Fuel Cells, such as La0.8Sr0.2MnO3-δ and La0.6Sr0.4Co1-xFexO3-δ (x = 0, 0.2, 0.8 and 1). The electrode microstructure is composed by two layers; the inner layer is a porous electrolyte scaffold homogeneously coated by cathode nanoparticles, providing an increased number of triple phase boundary sites for oxygen reduction, whereas, the top layer is formed by only cathode nanoparticles and acts mainly as a current collector. Polarization resistance values as low as 0.07 and 1.0 Ω cm2 at 600 and 450 °C, respectively, are obtained at open circuit voltage. This alternative approach has several advantages with respect to the traditional wet infiltration method for large area electrode fabrication, such as higher reproducibility, shorter preparation time in a single thermal deposition step, and easy implementation at industrial scale as a continuous process.

  11. Nano-designing of Mg doped phosphate tungsten bronzes and SiO2 composite obtained by ultrasonic spray pyrolysis method.

    PubMed

    Jokanovic, V; Nedic, Z

    2010-01-01

    In this study, the structure and substructure of SiO(2)-Mg phosphate tungsten bronzes, MgPTB, (MgHPW(12)O(40).29H(2)O) obtained by ultrasonic spray pyrolysis method from a silica sol, and a MgPTB solution, obtained by the ion exchange method, as precursors were investigated. The mechanism of the formation of aerosol droplets is discussed. Phase composition, structure and substructure of SiO(2)-MgPTB particles were investigated by X-ray powder diffraction (XRPD) analysis, transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Good agreement between the theoretically predicted values for the mean diameters of particles and subparticles (1.27 microm and 75.4 nm, respectively) and the experimentally obtained ones (1.17 microm and 65-90 nm) was found. This agreement confirms the applicability of the model to get a satisfactory prediction of the most important data related to the nano-structural design of SiO(2)-MgPTB powders. PMID:19501536

  12. Production and characterization of submicron hematite (α−Fe{sub 2}O{sub 3}) particles by ultrasonic spray pyrolysis method

    SciTech Connect

    Kırcı, Burak; Ebin, Burçak; Gürmen, Sebahattin

    2013-12-16

    The ultrasonic spray pyrolysis (USP) method has been used to prepare submicron hematite (α−Fe{sub 2}O{sub 3}) particles using two different industrial pickling solutions of iron chloride (41 g/L FeCl{sub 2} and 54 g/L FeCl{sub 3}) Particles were obtained by thermal decomposition of generated aerosols from precursor solutions using 1.7 MHz ultrasonic atomizer. Reaction temperature was set up at 800 °C and aerosol droplets were carried into the heated zone by 0.7 L/min air flow rate. X-Ray Diffraction (XRD) studies were used to determine the crystal structure and crystallite size of the particles. Results indicate that patterns correspond to hematite phase with rhombohedral crystal structure (space group: R3c). The crystallite sizes of particles prepared from FeCl{sub 2} and FeCl{sub 3} 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.

  13. 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

    Halim, Abdul; Setyawan, Heru; Machmudah, Siti; Nurtono, Tantular; Winardi, Sugeng

    2014-02-24

    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.

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

    PubMed

    Wu, Chia-Ching; Yang, Cheng-Fu

    2013-06-12

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-09-01

    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.

  16. Flame spray pyrolysis for sensing at the nanoscale.

    PubMed

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

    2013-11-01

    Progress in developing novel gas sensors based on semiconducting metal oxides (SMOX) has been hindered by the cumbersome fabrication technologies currently employed. They involve time intensive synthesis procedures for gaining sensitive materials and preparation of the inks employed for realizing sensing layers. In this paper we review the opportunities offered by the relatively young method of flame spray pyrolysis, with which it is possible not only to synthesize a broad selection of SMOX in pure or doped form, but also to simultaneously deposit thick and highly porous gas sensitive films on a variety of substrates. In less than ten years the properties of nine base materials have been evaluated for all most relevant target gases and the obtained results are promising for future development. PMID:24113649

  17. Deposition and characterization of La 2Ti 2O 7 thin films via spray pyrolysis process

    NASA Astrophysics Data System (ADS)

    Todorovsky, D. S.; Todorovska, R. V.; Milanova, M. M.; Kovacheva, D. G.

    2007-03-01

    Thin films of La 2Ti 2O 7 have been deposited on fused silica and Si substrates by a spray pyrolysis method using ethylene glycol solution of La(III)-Ti(IV)-citrate complexes as starting material and O 2 as a carrier gas. The composition, crystal structure and morphology of the films are studied.

  18. Tailoring of optical band gap by varying Zn content in Cd1-xZnxS thin films prepared by spray pyrolysis method

    NASA Astrophysics Data System (ADS)

    Kumar, Vipin; Sharma, D. K.; Agrawal, Sonalika; Sharma, Kapil K.; Dwivedi, D. K.; Bansal, M. K.

    2016-05-01

    Cd1-XZnXS thin films (X = 0.2, 0.4, 0.6, 0.8) have been grown on glass substrate by spray pyrolysis technique using equimolar concentration aqueous solution of cadmium chloride, zinc acetate and thiourea. Prepared thin films have been characterized by UV-VIS spectrophotometer. The optical band gap of the films has been studied by transmission spectra in wavelength range 325-600nm. It has been observed that optical band gap increases with increasing zinc concentration. The optical band gap of these thin films varies from 2.59 to 3.20eV with increasing Zn content.

  19. Continuous Synthesis of Doped Pyrochlore Materials by Spray Pyrolysis for Auto-thermal Reforming Applications

    NASA Astrophysics Data System (ADS)

    Yancey, Jonathan

    The use of a spray-pyrolysis method is studied for the continuous synthesis of refractory oxide reforming catalyst for the conversion of hydrocarbon fuels to H2 and CO at 900°C. Nickel- and rhodium-doped zirconate pyrochlore materials with the formulas La1.89Ni2.81Y 0.25Ca0.11Zr1.47 and La1.89Rh 1.09Y0.25Ca0.11Zr1.641 were synthesized using the spray pyrolysis method. Both Pechini and glycine-nitrate precursor solutions were used in order to control the particle morphology, crystallinity, and surface area of the catalyst powder. Samples synthesized by the Pechini solution required post-synthesis heat treatment to 1000 °C for 2 hours to form the fully-crystalline pyrochlore phase. Both the Ni- and Rh-doped compositions formed by the spray-pyrolysis method performed as reported elsewhere for powder produced by solid-state and Pechini bulk methods. The use of the glycine-nitrate precursor solution in the spray-pyrolysis resulted in the formation of fully crystalline pyrochlore catalyst for the Ni-doped composition without any additional high temperature treatment. The Rh-doped catalysts synthesized from the glycine-nitrate precursor did not form a fully crystalline material directly from the spray-pyrolysis process, but required a further thermal treatment to 800 °C for 8 hours to transform the powder and burn-off excess carbon remaining from the synthesis process. Rapid catalyst aging tests for the Rh-doped catalysts synthesized by spray-pyrolysis (using either the Pechini and glycine-nitrate precursor solutions) produced stable and active catalysts achieving equilibrium hydrogen yield of 90% for 15 hours. To conclude, the work showed that through proper chemical design of the precursor system, a high surface area, chemically active, and stable zirconate pyrochlore catalyst could be synthesized efficiently by the spray-pyrolysis method developed.

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

    NASA Astrophysics Data System (ADS)

    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

    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.

  1. Fabrication of functional nanomaterials using flame assisted spray pyrolysis

    SciTech Connect

    Purwanto, Agus

    2014-02-24

    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.

  2. Using of SnO{sub 2} deposition by spray pyrolysis method for thin film gas sensors (TFGS) manufacturing

    SciTech Connect

    Dmitriev, S.V.; Korotchenkov, G.S.; Brynzari, V.I.

    1996-12-31

    This report presents results of investigations aimed to TFGS technology elaboration. As follows from the results of electronic model of TFGS and technological possibilities optimal parameters of gas sensitive films are: the concentration of charge carriers in the film - 10<17> - 10<19> cm<-3> and film thickness d - 30-100 rim. At that for getting high reproducibility of TFGS parameters these parameters of the films must have high degree of surface uniformity. Other aspects of the problem of gas sensitive films deposition are bounded with the fact that gas sensitive films have to deposit on the already formed by collective methods {open_quotes}chip{close_quotes} of TFGS, and that gas sensors have high temperature active zones. So, for minimization of degradation effects in {open_quotes}chip{close_quotes}, the chosen method must provide: high deposition rate, low deposition temperature, high gas sensitivity, and high demanded stoichiometry of tin oxide films. The gas detection performance of these sensors was evaluated for methane, hydrogen, carbon monoxide, and propane.

  3. Laser-induced damage to spray pyrolysis deposited transparent conducting films

    NASA Astrophysics Data System (ADS)

    Radhakrishnan, P.; Sathianandan, K.; Subhash, N.

    1986-02-01

    Laser-induced damage study of transparent conducting coatings of tin oxide prepared by spray pyrolysis has been made using a dye Q-switched Nd:glass laser emitting 25-ns (FWHM) pulses at 1062 nm. For comparison tin oxide films prepared by the chemical vapor deposition (CVD) method and indium tin oxide (ITO) prepared by the reactive RF sputtering method have also been damage tested. The study reveals that the spray pyrolysis method yields good electrical and optical quality films with a damage threshold value of 5.2 + or - 0.3 J/sq cm. Though CVD technique provides the highest damage threshold coatings (14.2 + or - 0.6 J/sq cm), their electrical characteristics and uniformity are inferior to RF-sputtered ITO films which have the best electrical properties and the lowest damage threshold values (1.3 + or - 0.1 J/sq cm).

  4. Properties of Transparent Zinc-Tin Oxide Conducting Films Prepared by Chemical Spray Pyrolysis

    NASA Astrophysics Data System (ADS)

    Martinez, Arturo I.; Garcia, Benjamin A.; Acosta, Dwight R.

    2005-06-01

    In this work we have prepared thin films of zinc-tin oxide by the chemical spray pyrolysis method. The structural, electrical and optical properties were studied for all films as a function of the zinc content in the starting solution, yielding values of electrical resistivity (ρ), Hall mobility (μ), carrier concentration (n), and optical transmission (T) suitable for optoelectronic applications, e.g. our optimal values were ρ = 3.56×10-2 Ω cm and T = 0.77.

  5. Deposition of YBCO films by high temperature spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Shields, T. C.; Abell, J. S.; Button, T. W.; Chakalov, R. A.; Chakalova, R. I.; Cai, C.; Haessler, W.; Eickemeyer, J.; de Boer, B.

    2002-08-01

    The fabrication of YBCO coated conductors on flexible textured metallic substrates requires the deposition of biaxially textured buffer layers and superconducting films. In this study we have prepared YBCO thin films on single crystal SrTiO 3 substrates and cube textured Ni substrates by spray pyrolysis. The Ni substrates have been pre-buffered with CeO 2/YSZ/CeO 2, layers deposited by pulsed laser deposition. Spray pyrolysis of nitrate solutions has been performed directly on heated substrates at temperatures between 800 and 900 °C without need for a subsequent annealing step. YBCO films deposited on both types of substrate are biaxially textured. Full width half maximum values determined from φ-scans are 8° and 20° for films on SrTiO 3 and buffered Ni substrates respectively. A transport Jc value of 1.2×10 5 A/cm 2 at 77 K and zero field has been achieved on SrTiO 3 ( T c onset=91 K, ΔTc=6 K). χ ac susceptibility measurements of films on buffered Ni substrates show Tc onsets of 88 K with ΔTc=18 K.

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

    NASA Astrophysics Data System (ADS)

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

    2012-01-01

    In this paper, the SnO2-Al2O3 binary thin-film system has been deposited on a glass substrate by the spray pyrolysis technique. The effect of aluminum concentration on the structural, electrical, thermoelectrical, optical and photoconductivity properties of films was studied. The [Al]/[Sn] atomic ratio was in the range 0-100 at.% in solution. X-ray diffraction analysis shows that all films with different doping levels have polycrystalline SnO2 cassiterite phase. At doping levels of 40 at.% and above, the Al2O3 phase was observed and the sheet resistance of the films increased with increasing Al doping in the ranges from 5 at.% to less than 40 at.% and more than 60 at.% due to the substitution of Al3+ with Sn4+. Minimum sheet resistance of films was found in the range 40-60 at.%. Using Hall effect measurements, the majority carriers concentration obtained was of the order of 1018 cm-3. Hall effect and thermoelectrical measurements show that at doping levels between 10 and 20% and also higher than 60 at.%, majority carriers change from electrons (n-type conduction) to holes (p-type conduction). Also, a higher Seebeck coefficient value equal to -341 μV K-1 was obtained for the 30 at.% Al-doping level. The average transmittance of the films at low doping levels was about 75-90%. The photoconductivity properties of SnO2-Al2O3 thin films increased with increasing doping level.

  7. SnS2 Thin Film Deposition by Spray Pyrolysis

    NASA Astrophysics Data System (ADS)

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

    2012-06-01

    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.

  8. Titania by spray pyrolysis for photocatalytic destruction of organics in aqueous solutions

    SciTech Connect

    Fotou, G.P.; Himebaugh, L.; Kodas, T.T.; Wu, M.

    1996-12-31

    In this study, the potential of spray pyrolysis and spray calcination for the synthesis of effective titanium dioxide photocatalysts is explored. The product titanium dioxide powders were used in the photoassisted oxidation of salicylic acid in aqueous solutions. Titania particles were produced by spray pyrolysis of dihydroxybis titanium solutions in water at concentrations between 20 to 70% by volume at temperatures from 500 to 1100{degrees}C. Powders were made by spray calcination of titanium hydrolysate solutions at temperatures from 700 to 900 {degrees}C. Spray pyrolysis produced titania particles which were partially hollow. Spray calcination resulted in agglomerates which consisted of 15 nm primary particles that showed high photoactivity in the photooxidation of aqueous salicylic acid solutions. Doping with palladium oxide or ruthenium oxides did not improve the photocatalytic activity of these powders. 6 refs., 3 figs.

  9. Metal semiconductor transition in undoped ZnO films deposited by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Kavasoglu, Nese; Sertap Kavasoglu, A.

    2008-08-01

    ZnO films were deposited on glass substrate by using spray pyrolysis method. Films were deposited at different solution molarities 0.02 and 0.1 M. The films are highly transparent in the visible range of the electromagnetic spectrum with a transmission reaching up values to 90%. Band gaps were calculated as 3.24 and 3.28 eV with the help of transmission spectrums. When the solution molarity of the sprayed solution is increased from 0.02 to 0.1 M, carrier concentrations of the films increase from 1.6×10 19 cm -3 to 5.1×10 19 cm -3. Temperature-dependent conductivity measurements of these conducting and transparent films also showed, for the first time, a metal-semiconductor transition (MST). The deposited ZnO films show metallic conductivity above ∼420 K and semiconducting behavior at temperatures below it.

  10. Effect of precursor concentration and spray pyrolysis temperature upon hydroxyapatite particle size and density.

    PubMed

    Cho, Jung Sang; Lee, Jeong-Cheol; Rhee, Sang-Hoon

    2016-02-01

    In the synthesis of hydroxyapatite powders by spray pyrolysis, control of the particle size was investigated by varying the initial concentration of the precursor solution and the pyrolysis temperature. Calcium phosphate solutions (Ca/P ratio of 1.67) with a range of concentrations from 0.1 to 2.0 mol/L were prepared by dissolving calcium nitrate tetrahydrate and diammonium hydrogen phosphate in deionized water and subsequently adding nitric acid. Hydroxyapatite powders were then synthesized by spray pyrolysis at 900°C and at 1500°C, using these calcium phosphate precursor solutions, under the fixed carrier gas flow rate of 10 L/min. The particle size decreased as the precursor concentration decreased and the spray pyrolysis temperature increased. Sinterability tests conducted at 1100°C for 1 h showed that the smaller and denser the particles were, the higher the relative densities were of sintered hydroxyapatite disks formed from these particles. The practical implication of these results is that highly sinterable small and dense hydroxyapatite particles can be synthesized by means of spray pyrolysis using a low-concentration precursor solution and a high pyrolysis temperature under a fixed carrier gas flow rate.

  11. Methods and apparatuses for preparing upgraded pyrolysis oil

    DOEpatents

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

    2013-10-01

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

  12. Synthesis and characterization of ZnO nano and micro structures grown by low temperature spray pyrolysis and vapor transport.

    PubMed

    Agouram, S; Bushiri, M J; Montenegro, D N; Reig, C; Martínez-Tomás, M C; Muñoz-Sanjosé, V

    2012-08-01

    In this work we present a systematic study of ZnO micro and nanostructures grown by spray pyrolysis (SP) and by physical vapour transport (PVT) on glass and c-sapphire substrates at low temperatures. Optimised growth conditions have allowed to obtain homogeneous ZnO nanolayers composed of quasi-spherical nanoparticles in the range 2 to 8 nm by spray pyrolysis, while by PVT the selected growth conditions allow to produce a wide variety of morphologies (tripods, grains, arrows and wires) of nano and microsize dimension. Grazing incidence X-ray diffraction, field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) and energy dispersive X-ray spectroscopy (EDX) were used as characterization techniques in the investigation of structural, morphological and compositional nature of these nanostructures in relation with the growth method.

  13. Synthesis of TiO{sub 2} core/RuO{sub 2} shell particles using multistep ultrasonic spray pyrolysis

    SciTech Connect

    Stopic, Srecko; Friedrich, Bernd; Schroeder, Michael; Weirich, Thomas E.

    2013-09-01

    Graphical abstract: - Highlights: • TiO{sub 2} core/RuO{sub 2} shell submicron-particles were prepared via a sequential spray pyrolysis. • Spherical particles have the mean particle diameters between 200 and 400 nm. • This method is promising for synthesis of core–shell and core–multishell materials. - Abstract: Spherical submicron-particles with TiO{sub 2} core–RuO{sub 2} shell structure have been synthesized by employing sequential ultrasonic spray pyrolysis. The particles have been investigated by X-ray powder diffraction, scanning electron microscopy and different transmission electron microscopy techniques. The quality of the core–shell structure of the particles has been confirmed by comparison of the experimental data with those generated on the basis of a hard sphere core–shell model. It has been found that the mixing of the Ru-containing aerosol with the TiO{sub 2} particle stream has a significant impact on the core–shell formation. The method introduced in this study can probably be applied for preparation of core–shell and core–multishell materials that are difficult to synthesize in a single step spray pyrolysis process.

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

    SciTech Connect

    Halmenschlager, C.M.; Neagu, R.; Rose, L.; Malfatti, C.F.

    2013-02-15

    Graphical abstract: Gas-tight CGO made by spray pyrolysis suitable to be used as SOFC electrolyte. Display Omitted Highlights: ► Dense and crystalline CGO films deposited by spray pyrolysis on various substrates. ► Solvent did not have a strong influence on the film microstructure, defect concentration or thickness. ► The substrate did not have a strong influence on the film microstructure, defect concentration or thickness. ► Films with at least 2.5 μm of thickness presented high impermeability. ► The films obtained are suitable to use as a SOFC electrolyte. -- Abstract: This work presents the results of a process of optimization applied to gadolinia-doped ceria (Ce{sub 0.8}Gd{sub 0.2}O{sub 1.9−x}, or CGO) thin films, deposited by spray pyrolysis (SP). Spray pyrolysis is a high thermal deposition method that combines material deposition and heat treatment. This combination is advantageous since the post-deposition heat treatment step is not necessary. However, stresses are solidified in the coating during the deposition, which may lead to the initiation of a crack in the coating. The aim of this work was to achieve thin, dense, and continuous CGO coatings, which may be used as gas separation membranes and as a solid state electrochemical interfaces. Dense, flat, low-defect substrates such as silica slides, silicon mono crystal wafers, and porous substrates were used as substrates in this work. Cerium ammonium nitrate and gadolinium acetylacetonate were dissolved in ethanol and butyl carbitol to form a precursor solution that was sprayed on the heated substrates. Process parameters such as solvent composition, deposition rate and different heating regimes were analyzed. The microstructure was analyzed by secondary electron microscopy (SEM) and was found that thin, dense, and defect-free films could be produced on dense and porous substrates. The results obtained show that it is possible to obtain a CGO dense film deposited by spray pyrolysis. X

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

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

    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.

  16. Domain switching in spray pyrolysis-deposited nano-crystalline BiFeO3 films

    NASA Astrophysics Data System (ADS)

    Annapu Reddy, V.; Pathak, N. P.; Nath, R.

    2012-12-01

    Single-phase nano-scale BiFeO3 (BFO) films have been prepared under a controlled substrate temperature by a simple spray pyrolysis method. Fourier-transform infrared spectroscopy results indicate that single-phase BFO is deposited at low temperature. A magnetoelectric coupling to the anti-ferromagnetic and α-β phase transitions was observed at 350.2 and 832.8 °C, respectively. The capacitance-voltage (C-V) curves exhibit two coercive fields corresponding to ferroelastic (71° and 109°) and ferroelectric (180°) domains. Ferroelectric domain switching is dominant at lower electric fields. A non-volatile domain switching in the BFO films can prevent domain wall pinning and can enhance fatigue behavior in the films.

  17. Preparation and characterization of tin diselenide thin film by spray pyrolysis technique

    SciTech Connect

    Amalraj, L.; Jayachandran, M.; Sanjeeviraja, C. . E-mail: sanjeeviraja@rediffmail.com

    2004-12-02

    Tin diselenide (SnSe{sub 2}) thin film is deposited on to non-conducting glass substrate by spray pyrolysis technique at an optimized substrate temperature of 523 K. Hot probe method is used to identify the type of conductivity of the film to be an n-type semiconductor. X-ray diffraction study reveals the polycrystalline nature of the film with a preferential orientation growth. Spherical shaped grains with an average diameter of 233 nm are observed from the SEM photograph. The elemental composition on the surface of the film is analyzed with EDAX spectrum and formed almost in stoichiometric in composition. Room temperature resistivity of 1.27 x 10{sup 4} {omega} cm is determined using the linear four-probe method. Activation energy of 0.058 eV is determined by studying the variation of resistivity of the film with temperature. Optical absorption spectrum of this sprayed SnSe{sub 2} thin film is analyzed and found to have a direct allowed transition with a band gap of 1.48 eV.

  18. Mn-Doped Zn2SiO4 Phosphors Synthesis Using Flame Spray Pyrolysis

    NASA Astrophysics Data System (ADS)

    Lee, Jae Seok; Oh, Myoung Hwan; Kumar, Purushottam; Khanna, Aniruddh; Singh, Rajiv K.; Ranade, Madhav B.

    2011-09-01

    Zn2SiO4:Mn2+ particles are used as green phosphors in plasma display panels and cathode ray tubes. In this study, we report the synthesis of zinc silicate phosphors by flame spray pyrolysis using different Zn-sources and under different process conditions. The XRD and luminescence measurement showed the phosphors prepared from Zn-nitrate source to have better crystallinity and emission characteristics. The luminescence properties of the phosphor particles were found to improve both at higher methane flow rates during pyrolysis and at higher annealing temperatures.

  19. Ultrasonic spray pyrolysis growth of ZnO and ZnO:Al nanostructured films: Application to photocatalysis

    SciTech Connect

    Kenanakis, G.; Katsarakis, N.

    2014-12-15

    Highlights: • Al–ZnO thin films and nanostructures were obtained by ultrasonic spray pyrolysis. • The texture and morphology of the samples depend on the deposition parameters. • The photocatalytic degradation of stearic acid was studied upon UV-A irradiation. - Abstract: Pure and Al-doped ZnO (Al = 1, 3, 5%) nanostructured thin films were grown at 400 °C on glass substrates by ultrasonic spray pyrolysis, a simple, environmental-friendly and inexpensive method, using aqueous solutions as precursors. The structural and morphological characteristics of the samples depend drastically on deposition parameters; ZnO nanostructured films, nanopetals and nanorods were systematically obtained by simply varying the precursor solution and/or the spraying time. Transmittance measurements have shown that all samples are transparent in the visible wavelength region. Finally, the photocatalytic properties of the samples were investigated against the degradation of stearic acid under UV-A light illumination (365 nm); both pure and Al-doped ZnO nanostructured thin films show good photocatalytic activity regarding the degradation of stearic acid, due to their good crystallinity and large surface area.

  20. Low-Temperature Growth of ZnO Films by Spray Pyrolysis

    NASA Astrophysics Data System (ADS)

    Yoshino, Kenji; Takemoto, Yujin; Oshima, Minoru; Toyota, Kouji; Inaba, Koichiro; Haga, Ken-ichi; Tokudome, Koichi

    2011-04-01

    Nondoped ZnO film on a polyethylene terephthalate film was successfully grown by conventional spray pyrolysis at 100 °C using a diethylzinc-based solution under air atmosphere. The samples had an average optical transmittance of more than 80%, a flat surface, and an a-axis orientation from the optical transmittance, scanning electron microscopy, and X-ray diffraction measurements, respectively. It was assumed that the growth at low temperature was attributed to atmospheric oxygen and/or steam.

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

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

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

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

    NASA Astrophysics Data System (ADS)

    Goyal, Ankit; Lakhotia, Harish

    2013-06-01

    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.

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

    PubMed

    Jokanović, V; Nedić, Z; Colović, B

    2008-12-01

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

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

    SciTech Connect

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

    2003-01-01

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

  5. Zirconium doped TiO2 thin films deposited by chemical spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Juma, A.; Oja Acik, I.; Oluwabi, A. T.; Mere, A.; Mikli, V.; Danilson, M.; Krunks, M.

    2016-11-01

    Chemical spray pyrolysis (CSP) is a flexible deposition technique that allows for mixing of the precursor solutions in different proportions suitable for doping thin films. The CSP method was used to dope TiO2 thin films with Zr by adding zirconium(IV) acetylacetonate into a solution of titanium(IV) isopropoxide in ethanol stabilized by acetylacetone at [Zr]/[Ti] of 0, 5, 10 and 20 at%. The Zr-doped TiO2 thin films were uniform and homogeneous showing much smaller grains than the undoped TiO2 films. Zr stabilized the anatase phase to temperatures above 800 °C depending on Zr concentration in the spray solution. The concentration of Zr determined by XPS was 6.4 at% for the thin film deposited from the 20 at% solution. According to AFM studies, Zr doping decreased the root mean square roughness of TiO2 film from 5.9 to 1.1 nm. An XRD study of samples with the highest Zr amount showed the ZrTiO4 phase started forming after annealing at 800 °C. The optical band gap for TiO2 decreased from 3.3 eV to 3.0 eV after annealing at 800 °C but for the TiO2:Zr(20) film it remained at 3.4 eV. The dielectric constant increased by more than four times with Zr-doping and this was associated with the change in the bond formations caused by substitution of Ti by Zr in the lattice.

  6. Production and characterization of ZnO nanoparticles and porous particles by ultrasonic spray pyrolysis using a zinc nitrate precursor

    NASA Astrophysics Data System (ADS)

    Ebin, Burçak; Arıg, Elif; Özkal, Burak; Gürmen, Sebahattin

    2012-07-01

    ZnO nanoparticles and porous particles were produced by an ultrasonic spray pyrolysis method using a zinc nitrate precursor at various temperatures under air atmosphere. The effects of reaction temperature on the size and morphology of ZnO particles were investigated. The samples were characterized by energy dispersive spectroscopy, X-ray diffraction, transmission electron microscopy, and scanning electron microscopy. ZnO particles were obtained in a hexagonal crystal structure and the crystallite shapes changed from spherical to hexagonal by elevating the reaction temperature. The crystallite size grew by increasing the temperature, in spite of reducing the residence time in the heated zone. ZnO nanoparticles were obtained at the lowest reaction temperature and ZnO porous particles, formed by aggregation of ZnO nanoparticles due to effective sintering, were prepared at higher temperatures. The results showed that the properties of ZnO particles can be controlled by changing the reaction temperature in the ultrasonic spray pyrolysis method.

  7. Corrosion resistance of zirconium oxynitride coatings deposited via DC unbalanced magnetron sputtering and spray pyrolysis-nitriding

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

    ZrOxNy/ZrO2 thin films were deposited on stainless steel using two different methods: ultrasonic spray pyrolysis-nitriding (SPY-N) and the DC unbalanced magnetron sputtering technique (UBMS). Using the first method, ZrO2 was initially deposited and subsequently nitrided in an anhydrous ammonia atmosphere at 1023 K at atmospheric pressure. For UBMS, the film was deposited in an atmosphere of air/argon with a Φair/ΦAr flow ratio of 3.0. Structural analysis was carried out through X-ray diffraction (XRD), and morphological analysis was done through scanning electron microscopy (SEM) and atomic force microscopy (AFM). Chemical analysis was carried out using X-ray photoelectron spectroscopy (XPS). ZrOxNy rhombohedral polycrystalline film was produced with spray pyrolysis-nitriding, whereas using the UBMS technique, the oxynitride films grew with cubic Zr2ON2 crystalline structures preferentially oriented along the (2 2 2) plane. Upon chemical analysis of the surface, the coatings exhibited spectral lines of Zr3d, O1s, and N1s, characteristic of zirconium oxynitride/zirconia. SEM analysis showed the homogeneity of the films, and AFM showed morphological differences according to the deposition technique of the coatings. Zirconium oxynitride films enhanced the stainless steel's resistance to corrosion using both techniques. The protective efficacy was evaluated using electrochemical techniques based on linear polarization (LP). The results indicated that the layers provide good resistance to corrosion when exposed to chloride-containing media.

  8. Conductivity study of nitrogen-doped calcium zinc oxide prepared by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Hsu, Yu-Ting; Lan, Wen-How; Huang, Kai-Feng; Lin, Jia-Ching; Chang, Kuo-Jen

    2016-01-01

    In this study, the spray pyrolysis method was used to prepare unintentionally doped and nitrogen-doped calcium zinc oxide films by using zinc acetate, calcium nitrate precursor, and ammonium acetate precursor. Morphological and structural analyses were conducted using scanning electron microscopy and X-ray diffraction. The results indicated that film grain size decreased as the nitrogen doping was increased. Both calcium oxide and zinc oxide structures were identified in the unintentionally doped calcium zinc oxide. When nitrogen doping was introduced, the film mainly exhibited a zinc oxide structure with preferred (002) and (101) orientations. The concentration and mobility were investigated using a Hall measurement system. P-type films with a mobility and concentration of 10.6 cm2 V-1 s-1 and 2.8×1017 cm-3, respectively, were obtained. Moreover, according to a temperature-dependent conductivity analysis, an acceptor state with activation energy 0.266 eV dominated the p-type conduction for the unintentionally doped calcium zinc oxide. By contrast, a grain boundary with a barrier height of 0.274-0.292 eV dominated the hole conduction for the nitrogen-doped calcium zinc oxide films.

  9. Thin Fluorine-Doped Tin Oxide Films Prepared Using an Electric Field-Modified Spray Pyrolysis Deposition Technique

    NASA Astrophysics Data System (ADS)

    Gupta, Archana; Pandya, Dinesh K.; Kashyap, Subhash C.

    2004-12-01

    Very thin fluorine-doped tin oxide films (60-70 nm) were prepared on glass substrates at low deposition temperatures (275-300°C), these films showed an electrical resistivity of 3.2 × 10-4Ω-cm and a transparency of 88% at 625 nm with the application of a dc electric field on the film surface during growth using a spray pyrolysis deposition technique. In this first study of its kind, the applied electric field during growth by spray pyrolysis resulted in the reduction in the critical thickness and the increases in both the electrical conductivity and transparency of continuous films. The obtained X-ray diffraction (XRD) patterns showed that the films prepared with an electric field were polycrystalline, whereas those prepared without an electric field were amorphous. This method shows potential for producing very thin oxide films at a low deposition temperature with a high growth rate, an enhanced optical quality and an improved electrical conductivity.

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

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    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.

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

    SciTech Connect

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

    2014-04-24

    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.

  12. Structural and optical characterization of InAs nanocrystals deposited by spray pyrolysis

    SciTech Connect

    Mousa, A. M. Mohammed, M. A.; Kadhim, R.

    2015-03-30

    4-5 nm size InAs nanocrystals were prepared by spray pyrolysis technique on glass substrates from alkaline solution containing InCl{sub 3} and As{sub 2}O. X-Ray diffraction and absorption spectra suggested that the deposition conditions (deposition time and temperature) had a profound influence on the structure and thickness of deposited layers. The optical absorption band edges shifted to lower energy when increasing the thickness with respect to the bulk material. The marked blue shift of the optical absorption edge indicated a strong quantum confinement effect in InAs films.

  13. Fine-sized Tb3Al5O12:Ce phosphor powders prepared by spray pyrolysis from spray solution with ethylenediaminetetraacetic acid

    NASA Astrophysics Data System (ADS)

    Kim, Hyung Tae; Kim, Jung Hyun; Hong, Young Jun; Lee, Jung-Kul; Kang, Yun Chan

    2012-06-01

    Fine Tb2.91Al5O12:Ce0.09 (TAG:Ce) phosphor powders are prepared by spray pyrolysis from a spray solution with ethylenediaminetetraacetic acid (EDTA). EDTA is used as an organic additive to form hollow precursor powders as well as a chelating agent. The powders prepared from the spray solution with EDTA have mean sizes of 350, 400 and 604 nm at post-treatment temperatures of 1400°C, 1450°C and 1500°C, respectively. The phosphor powders prepared from the spray solution with EDTA have similar photoluminescence intensities at post-treatment temperatures of 1450°C and 1500°C. The photoluminescence intensity of the phosphor powders prepared from the spray solution with EDTA is 116% of that of the phosphor powders prepared from the spray solution without EDTA at a post-treatment temperature of 1450°C.

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

    PubMed

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

    2011-07-01

    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

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

    PubMed Central

    Rudin, Thomas; Wegner, Karsten

    2013-01-01

    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 Bi2O3 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 Bi2O3 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

  16. Study of optical and structural properties of CZTS thin films grown by co-evaporation and spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Moreno, R.; Ramirez, E. A.; Gordillo Guzmán, G.

    2016-02-01

    Results regarding optical and structural properties of Cu2ZnSnS4 (CZTS) thin films prepared by co-evaporation using a novel procedure are compared with those obtained with CZTS films grown using a solution based route. The lattice strain ε and crystallite size D of CZTS films prepared by co-evaporation and by spray pyrolysis were estimated through X-ray diffraction (XRD) measurements using Williamson-Hall-isotropic strain model. The results of estimated average crystallite size of CZTS films by Scherrer and Williamson-Hall plot methods were compared with AFM (atomic force microscopy) measurements. It was found that the average crystallite size measured by Williamson-Hall plot methods agree quite well with AFM results. Further, information regarding the influence of preparation method on both, crystalline phases and the formation of structural defects was achieved through Raman and Urbach energy measurements.

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

    NASA Astrophysics Data System (ADS)

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

    2008-02-01

    The structural and optical properties of pure and zinc doped tin oxide (SnO2) thin films have been studied in detail. Thin films of pure and zinc doped tin oxide (Zn : SnO2) were prepared on Si(1 0 0) and quartz substrates by the spray pyrolysis technique at a substrate temperature of 400 °C. The zinc dopant concentration was varied from 0 to 25 wt%. The films were systematically characterized by different methods to understand their structural and optical property variations, and the results were correlated. The x-ray diffraction (XRD) method shows that pure SnO2 films possess tetragonal crystalline structure with the preferred (1 1 0) orientation. Upon increasing the zinc concentration the preferred orientation changes from the (1 1 0) plane to the (2 0 0) plane, and at the same time the crystalline quality was found to be deteriorated. The Raman measurements also confirm the tetragonal structure of the films for the entire range of Zn doping. High resolution scanning electron microscopy measurements reveal that upon increasing the Zn concentration, the surface morphology of the films changes continuously and the grains also deteriorate. The elemental analysis of the films measured by energy dispersive XRD spectroscopy shows that the Zn concentration in the solid film is slightly less than that of the starting solution. Optical transmittance measurements of the films reveal that the films are fully transparent in the visible region. Upon increasing the Zn concentration, the band gap of the films decreases from 3.85 to 3.57 eV. Thus, the structural study performed by XRD and Raman spectroscopy clearly indicates the incorporation of Zn ion into SnO2 lattice, and the change in the optical properties of the films was directly attributed to the effect of Zn ion incorporation into SnO2 lattice.

  18. Surfactant-assisted ultrasonic spray pyrolysis of nickel oxide and lithium-doped nickel oxide thin films, toward electrochromic applications

    NASA Astrophysics Data System (ADS)

    Denayer, Jessica; Bister, Geoffroy; Simonis, Priscilla; Colson, Pierre; Maho, Anthony; Aubry, Philippe; Vertruyen, Bénédicte; Henrist, Catherine; Lardot, Véronique; Cambier, Francis; Cloots, Rudi

    2014-12-01

    Lithium-doped nickel oxide and undoped nickel oxide thin films have been deposited on FTO/glass substrates by a surfactant-assisted ultrasonic spray pyrolysis. The addition of polyethylene glycol in the sprayed solution has led to improved uniformity and reduced light scattering compared to films made without surfactant. Furthermore, the presence of lithium ions in NiO films has resulted in improved electrochromic performances (coloration contrast and efficiency), but with a slight decrease of the electrochromic switching kinetics.

  19. Electrochemical properties of tungsten sulfide-carbon composite microspheres prepared by spray pyrolysis.

    PubMed

    Choi, Seung Ho; Boo, Sung Jin; Lee, Jong-Heun; Kang, Yun Chan

    2014-01-01

    Tungsten sulfide (WS2)-carbon composite powders with superior electrochemical properties are prepared by a two-step process. WO3-carbon composite powders were first prepared by conventional spray pyrolysis, and they were then sulfidated to form WS2-carbon powders. Bare WS2 powders are also prepared by sulfidation of bare WO3 powders obtained by spray pyrolysis. Stacked graphitic layers could not be found in the bare WS2 and WS2-carbon composite powders. The amorphous bare WS2 and WS2-carbon composite powders have Brunauer-Emmett-Teller (BET) surface areas of 2.8 and 4 m(2) g(-1), respectively. The initial discharge and charge capacities of the WS2-carbon composite powders at a current density of 100 mA g(-1) are 1055 and 714 mA h g(-1), respectively, and the corresponding initial Coulombic efficiency is 68%. On the other hand, the initial discharge and charge capacities of the bare WS2 powders are 514 and 346 mA h g(-1), respectively. The discharge capacities of the WS2-carbon composite powders for the 2(nd) and 50(th) cycles are 716 and 555 mA h g(-1), respectively, and the corresponding capacity retention measured after first cycle is 78%.

  20. Electrochemical properties of tungsten sulfide–carbon composite microspheres prepared by spray pyrolysis

    PubMed Central

    Choi, Seung Ho; Boo, Sung Jin; Lee, Jong-Heun; Kang, Yun Chan

    2014-01-01

    Tungsten sulfide (WS2)–carbon composite powders with superior electrochemical properties are prepared by a two-step process. WO3-carbon composite powders were first prepared by conventional spray pyrolysis, and they were then sulfidated to form WS2-carbon powders. Bare WS2 powders are also prepared by sulfidation of bare WO3 powders obtained by spray pyrolysis. Stacked graphitic layers could not be found in the bare WS2 and WS2–carbon composite powders. The amorphous bare WS2 and WS2–carbon composite powders have Brunauer–Emmett–Teller (BET) surface areas of 2.8 and 4 m2 g−1, respectively. The initial discharge and charge capacities of the WS2–carbon composite powders at a current density of 100 mA g−1 are 1055 and 714 mA h g−1, respectively, and the corresponding initial Coulombic efficiency is 68%. On the other hand, the initial discharge and charge capacities of the bare WS2 powders are 514 and 346 mA h g−1, respectively. The discharge capacities of the WS2–carbon composite powders for the 2nd and 50th cycles are 716 and 555 mA h g−1, respectively, and the corresponding capacity retention measured after first cycle is 78%. PMID:25169439

  1. Antimony-Doped Tin Oxide Thin Films Grown by Home Made Spray Pyrolysis Technique

    NASA Astrophysics Data System (ADS)

    Yusuf, Gbadebo; Babatola, Babatunde Keji; Ishola, Abdulahi Dimeji; Awodugba, Ayodeji O.; Solar cell Collaboration

    2016-03-01

    Transparent conducting antimony-doped tin oxide (ATO) films have been deposited on glass substrates by home made spray pyrolysis technique. The structural, electrical and optical properties of the ATO films have been investigated as a function of Sb-doping level and annealing temperature. The optimum target composition for high conductivity and low resistivity was found to be 20 wt. % SnSb2 + 90 wt. ATO. Under optimized deposition conditions of 450oC annealing temperature, electrical resistivity of 5.2×10-4 Ω -cm, sheet resistance of 16.4 Ω/sq, average optical transmittance of 86% in the visible range, and average optical band-gap of 3.34eV were obtained. The film deposited at lower annealing temperature shows a relatively rough, loosely bound slightly porous surface morphology while the film deposited at higher annealing temperature shows uniformly distributed grains of greater size. Keywords: Annealing, Doping, Homemade spray pyrolysis, Tin oxide, Resistivity

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

    NASA Astrophysics Data System (ADS)

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

    1998-10-01

    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.

  3. Boron doped nanostructure ZnO films deposited by ultrasonic spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Karakaya, Seniye; Ozbas, Omer

    2015-02-01

    ZnO is an II-VI compound semiconductor with a wide direct band gap of 3.3 eV at room temperature. Doped with group III elements (B, Al or Ga), it becomes an attractive candidate to replace tin oxide (SnO2) or indium tin oxide (ITO) as transparent conducting electrodes in solar cell devices and flat panel display due to competitive electrical and optical properties. In this work, ZnO and boron doped ZnO (ZnO:B) films have been deposited onto glass substrates at 350 ± 5 °C by a cost-efficient ultrasonic spray pyrolysis technique. The optical, structural, morphological and electrical properties of nanostructure undoped and ZnO:B films have been investigated. Electrical resistivity of films has been analyzed by four-probe technique. Optical properties and thicknesses of the films have been examined in the wavelength range 1200-1600 nm by using spectroscopic ellipsometry (SE) measurements. The optical constants (refractive index (n) and extinction coefficient (k)) and the thicknesses of the films have been fitted according to Cauchy model. The optical method has been used to determine the band gap value of the films. Transmission spectra have been taken by UV spectrophotometer. It is found that both ZnO and ZnO:B films have high average optical transmission (≥80%). X-ray diffraction (XRD) patterns indicate that the obtained ZnO has a hexagonal wurtzite type structure. The morphological properties of the films were studied by atomic force microscopy (AFM). The surface morphology of the nanostructure films is found to depend on the concentration of B. As a result, ZnO:B films are promising contender for their potential use as transparent window layer and electrodes in solar cells.

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

    NASA Astrophysics Data System (ADS)

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

    2007-02-01

    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.

  5. Formation of CuAlO2 Film by Ultrasonic Spray Pyrolysis

    NASA Astrophysics Data System (ADS)

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

    2011-10-01

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

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

    PubMed Central

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

    2014-01-01

    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. PMID:25551068

  7. Properties of NiO thin films deposited by intermittent spray pyrolysis process

    NASA Astrophysics Data System (ADS)

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

    2007-02-01

    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.

  8. Methods for deoxygenating biomass-derived pyrolysis oil

    SciTech Connect

    Brandvold, Timothy A.

    2015-07-14

    Methods for deoxygenating a biomass-derived pyrolysis oil are provided. A method comprising the steps of diluting the biomass-derived pyrolysis oil with a phenolic-containing diluent to form a diluted pyoil-phenolic feed is provided. The diluted pyoil-phenolic feed is contacted with a deoxygenating catalyst in the presence of hydrogen at hydroprocessing conditions effective to form a low-oxygen biomass-derived pyrolysis oil effluent.

  9. Methods for deoxygenating biomass-derived pyrolysis oil

    DOEpatents

    Baird, Lance Awender; Brandvold, Timothy A.

    2015-06-30

    Methods for deoxygenating a biomass-derived pyrolysis oil are provided. A method for deoxygenating a biomass-derived pyrolysis oil comprising the steps of combining a biomass-derived pyrolysis oil stream with a heated low-oxygen-pyoil diluent recycle stream to form a heated diluted pyoil feed stream is provided. The heated diluted pyoil feed stream has a feed temperature of about 150.degree. C. or greater. The heated diluted pyoil feed stream is contacted with a first deoxygenating catalyst in the presence of hydrogen at first hydroprocessing conditions effective to form a low-oxygen biomass-derived pyrolysis oil effluent.

  10. Field emission property of ZnO nanowires prepared by ultrasonic spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Htay, Myo Than; Hashimoto, Yoshio

    2015-08-01

    The field emission property of cold cathode emitters utilizing the ZnO nanowires with various conditions prepared by ultrasonic spray pyrolysis technique was discussed. It is found that the emission current was enhanced in the emitters having higher aspect ratio as well as smaller sheet resistance. Applying of post-annealing process, utilization of additional Mo back electrode in the cathode, and coating of Mo on the ZnO nanowires resulted in the improvement of the emission current and lowering the threshold voltage. A threshold voltage of about 5.5 V/μm to obtain 1.0 μA/cm2 was achieved in the sample prepared at the growth temperatures varying continuously from 250 °C to 300 °C.

  11. Solution-based carbohydrate synthesis of individual solid, hollow, and porous carbon nanospheres using spray pyrolysis.

    PubMed

    Wang, Chengwei; Wang, Yuan; Graser, Jake; Zhao, Ran; Gao, Fei; O'Connell, Michael J

    2013-12-23

    A facile and scalable solution-based, spray pyrolysis synthesis technique was used to synthesize individual carbon nanospheres with specific surface area (SSA) up to 1106 m(2)/g using a novel metal-salt catalyzed reaction. The carbon nanosphere diameters were tunable from 10 nm to several micrometers by varying the precursor concentrations. Solid, hollow, and porous carbon nanospheres were achieved by simply varying the ratio of catalyst and carbon source without using any templates. These hollow carbon nanospheres showed adsorption of to 300 mg of dye per gram of carbon, which is more than 15 times higher than that observed for conventional carbon black particles. When evaluated as supercapacitor electrode materials, specific capacitances of up to 112 F/g at a current density of 0.1 A/g were observed, with no capacitance loss after 20,000 cycles.

  12. Properties of antimony doped ZnO thin films deposited by spray pyrolysis technique

    SciTech Connect

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

    2015-07-15

    Antimony (Sb) doped zinc oxide (ZnO) thin films were deposited on the glass substrate at 450°C using spray pyrolysis technique. Effect of Sb doping on surface morphology structural, optical and electrical properties were studied. X-ray diffraction (XRD) analysis showed that both the undoped and doped ZnO thin films are polycrystalline in nature with (101) preferred orientation. SEM analysis showed a change in surface morphology of Sb doped ZnO thin films. Doping results in a marked increase in conductivity without affecting the transmittance of the films. ZnO films prepared with 3 at % Sb shows the lowest resistivity of 0.185 Ohm cm with a Hall mobility of 54.05 cm{sup 2} V{sup –1} s{sup –1}, and a hole concentration of 6.25 × 10{sup 17} cm{sup –3}.

  13. Synthesis of ZnO Microrods by the Spray Pyrolysis Technique

    NASA Astrophysics Data System (ADS)

    Ikhmayies, Shadia J.

    2016-08-01

    Zinc oxide (ZnO) microrods were synthesized by the spray pyrolysis technique on aluminum substrates at a substrate temperature of 350 ± 5°C. The samples were characterized by x-ray diffraction (XRD), x-ray fluorescence (XRF), scanning electron microscopy (SEM), and energy dispersion x-ray spectroscopy (EDX). XRD diffractograms presented the wurtzite (hexagonal) structure with (002) as the preferential orientation. The SEM observations showed typical microrods of hexagonal cross sections with lengths in the range 1.0-2.5 μm and diameter in the range 300-400 nm. XRF and EDX analysis revealed that the samples contain chlorine, and other impurities, which are related to the aluminum substrate and the starting material zinc chloride (ZnCl2). It is found that the microrods are rich in oxygen, which make them of potential use in gas sensors, besides solar cells, lithium ion batteries and other electo-optic devices.

  14. Some physical properties of CdO:F thin films prepared by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Bagheri Khatibani, A.; Hallaj, Z. A.; Rozati, S. M.

    2015-12-01

    Different attractions of cadmium oxide in the field of materials science especially in semiconductor science and engineering encouraged us to study its physical properties. The preparation of a transparent conducting cadmium oxide doped with various concentration of fluorine (0%, 3%, 6%) in the spray solution on a glass substrate by spray pyrolysis is reported. The structural, morphological, electrical and optical properties were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), Hall effect and UV-visible spectrophotometry. Different optical quantities such as optical band gap, refractive index, extinction coefficient, Urbach energy, oscillator energy, dispersion energy and nonlinear optical susceptibility were determined. The XRD, SEM, Hall effect and AFM showed the doping concentration effects on CdO thin-films properties. Observations such as the decrease of the sheet resistance to 9.20 (Ω/Box), the mobility increase up to 29.3(cm2/V·s), the transmittance up to 84% and the increase of the band gap up to 2.76(eV) state the sample CdO:F 3% is the best candidate for transparent and conducting oxide application.

  15. Pyrolysis and catalytic pyrolysis as a recycling method of waste CDs originating from polycarbonate and HIPS

    SciTech Connect

    Antonakou, E.V.; Kalogiannis, K.G.; Stephanidis, S.D.; Triantafyllidis, K.S.; Lappas, A.A.; Achilias, D.S.

    2014-12-15

    Highlights: • Thermal and catalytic pyrolysis is a powerful method for recycling of WEEEs. • Liquid products obtained from the pyrolysis of PC or HIPS found in waste CDs are very different. • Mainly phenols are obtained from pyrolysis PC based wastes while aromatics from HIPS. • Use of MgO catalyst increases the amount of phenols from CD recycling compared to ZSM-5. • Use of MgO or ZSM-5 catalysts reduces the amount of styrene recovered from HIPS. - Abstract: Pyrolysis appears to be a promising recycling process since it could convert the disposed polymers to hydrocarbon based fuels or various useful chemicals. In the current study, two model polymers found in WEEEs, namely polycarbonate (PC) and high impact polystyrene (HIPS) and their counterparts found in waste commercial Compact Discs (CDs) were pyrolysed in a bench scale reactor. Both, thermal pyrolysis and pyrolysis in the presence of two catalytic materials (basic MgO and acidic ZSM-5 zeolite) was performed for all four types of polymers. Results have shown significant recovery of the monomers and valuable chemicals (phenols in the case of PC and aromatic hydrocarbons in the case of HIPS), while catalysts seem to decrease the selectivity towards the monomers and enhance the selectivity towards other desirable compounds.

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

    SciTech Connect

    Choi, Sungho; Kim, Kyoungun; Moon, Young-Min; Park, Byung-Yoon; Jung, Ha-Kyun

    2010-08-15

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

  17. Effect of solvent composition on oxide morphology during flame spray pyrolysis of metal nitrates.

    PubMed

    Strobel, Reto; Pratsinis, Sotiris E

    2011-05-28

    The effect of solvent composition on particle formation during flame spray pyrolysis of inexpensive metal-nitrates has been investigated for alumina, iron oxide, cobalt oxide, zinc oxide and magnesium oxide. The as-prepared materials were characterized by electron microscopy, nitrogen adsorption, X-ray diffraction (XRD) and disc centrifugation (XDC). The influence of solvent parameters such as boiling point, combustion enthalpy and chemical reactivity on formation of either homogeneous nanoparticles by evaporation/nucleation/coagulation (gas-to-particle conversion) or large particles through precipitation and conversion within the sprayed droplets (droplet-to-particle conversion) is discussed. For Al(2)O(3), Fe(2)O(3), Co(3)O(4) and partly also MgO, the presence of a carboxylic acid in the FSP solution resulted in homogeneous nanoparticles. This is attributed to formation of volatile metal carboxylates in solution as evidenced by attenuated total reflectance spectroscopy (ATR). For ZnO and MgO rather homogeneous nanoparticles were formed regardless of solvent composition. For ZnO this is attributed to its relatively low dissociation temperature compared to other oxides. While for MgO this is traced to the high decomposition temperature of Mg(NO(3))(2) together with Mg(OH)(2)↔MgO transformations. Cobalt oxide (Co(3)O(4)) nanoparticles made by FSP were not aggregated but rather loosely agglomerated as determined by the excellent agreement between XRD- and XDC-derived crystallite and particle sizes, respectively, pointing out the potential of FSP to make non-aggregated particles. PMID:21468418

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

    NASA Astrophysics Data System (ADS)

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

    2008-07-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    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.

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

    SciTech Connect

    Ait Aouaj, M.; Diaz, R.; Belayachi, A.; Rueda, F.; Abd-Lefdil, M.

    2009-07-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    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.

  2. Investigation on vanadium oxide thin films deposited by spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Margoni, Mudaliar Mahesh; Mathuri, S.; Ramamurthi, K.; Babu, R. Ramesh; Sethuraman, K.

    2016-05-01

    Vanadium oxide thin films were deposited at 400 °C by spray pyrolysis technique using 0.1 M aqueous precursor solution of ammonium meta vanadate (AMV) with two different pH values. X-ray diffraction results showed that the film prepared using aqueous precursor AMV solution (solution A; pH 7) is amorphous in nature and the film prepared by adding HNO3 in the AMV aqua solution A (solution B; pH 3) is polycrystalline in nature. Vanadium oxide film prepared from the precursor solution B is in the mixed phases of V2O5 and V4O7. Crystallinity is improved for the film prepared using solution B when compared to film prepared from solution A. Crystallite size, strain and dislocation density calculated for the film prepared from solution B is respectively 72.1 nm, 0.4554 × 10-3 lin.-2m-4 and 1.7263 × 1014 lin.m-2. Morphology study revealed that the size of the flakes formed on the surface of the films is influenced by the pH of the precursor solution. Average Visible Transmittance and maximum transmittance of the deposited films exceed 70% and the direct optical band gap value calculated for the films deposited from A and B solution is 1.91 eV and 2.08 eV respectively.

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

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

    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-μm-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.

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

    PubMed

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

    2012-09-25

    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 (λ > 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

  5. Spray pyrolysis synthesis of ZnS nanoparticles from a single-source precursor.

    PubMed

    Liu, Sha; Zhang, Hongwang; Swihart, Mark T

    2009-06-10

    ZnS, a II-VI semiconductor with a relatively high direct bandgap (approximately 3.6 eV) in the near-UV region, has potential applications in areas such as solar cells, lasers and displays. In addition, ZnS nanoparticles can be applied as phosphors, probes for bioimaging, emitters in light emitting diodes and photocatalysts. Here, we report synthesis of cubic ZnS nanoparticles from a low-cost single-source precursor in a continuous spray pyrolysis reactor. In this approach, the evaporation and decomposition of precursor and nucleation of particles occur sequentially. Product particles were characterized by HRTEM, XRD, and EDX. Particles with diameters ranging from 2 to 7 nm were produced. HF was used to remove ZnO impurities and other surface contamination. As-synthesized ZnS nanoparticles exhibit blue photoluminescence near 440 nm under UV excitation and have quantum yields up to 15% after HF treatment. This demonstrates a potentially general approach for continuous low-cost synthesis of semiconductor quantum dots for applications where tight control of the size distribution is less important than scalable, economical production.

  6. Synthesis of nanocrystalline Cu2ZnSnS4 thin films grown by the spray-pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Chandel, Tarun; Singh, Joginder; Rajaram, P.

    2015-08-01

    Spray pyrolysis was used to deposit Cu2ZnSnS4 (CZTS) thin films on soda lime glass substrates at 300 °C. Aqueous solutions of copper chloride, zinc chloride, stannous chloride and thiourea were mixed together to form the spray liquid. The sprayed films were annealed under vacuum at 350 °C, 400 °C and 450 °C. Structural and optical characterization was performed on the CZTS films using X-ray diffraction (XRD) and UV-VIS spectrophotometry. XRD results indicate that the films are single phase nanocrystalline CZTS. Optical studies show that the optical gap values are 1.44 eV for the as-grown film and 1.46 eV, 1.48 eV and 1.49 eV for the films annealed at 350 °C, 400 °C and 450 °C, respectively.

  7. Correlation between porous structure and electrochemical properties of porous nanostructured vanadium pentoxide synthesized by novel spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Kong, Long; Taniguchi, Izumi

    2016-04-01

    Porous nanostructured vanadium pentoxide (V2O5) particles were successfully prepared by spray pyrolysis (SP) in a precursor solution with an ammonium nitrate (NH4NO3) additive. The correlation between the porous structure and the electrochemical properties of the V2O5 particles was investigated. The porous structure markedly changed upon increasing the concentration of NH4NO3 in the precursor solution from 0 to 0.408 mol L-1. Pore structure analysis based on N2 adsorption-desorption isotherm measurements indicated that porous nanostructured V2O5 particles with a pore size of less than 100 nm can be prepared by the novel SP method and that an increase in the NH4NO3 concentration in the precursor solution can enlarge the pores in the V2O5 particles, especially those with a size between 20 and 80 nm. The porous nanostructured V2O5 prepared with an NH4NO3 concentration of 0.272 mol L-1 exhibited a first discharge capacity of 400 mAh g-1 at 20 mA g-1. The unique porous structure of V2O5 particles significantly enhanced the rate performance and exhibited a first discharge capacity of 180 mAh g-1 at 1200 mA g-1, which is much higher than that of dense V2O5 particles (70 mAh g-1).

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

    NASA Astrophysics Data System (ADS)

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

    2006-01-01

    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.

  9. Optical, structural and electrical properties of tin doped indium oxide thin films prepared by spray-pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Subba Ramaiah, Kodigala; Sundara Raja, V.; Bhatnagar, A. K.; Tomlinson, R. D.; Pilkington, R. D.; Hill, A. E.; Chang, S. J.; Su, Y. K.; Juang, F. S.

    2000-07-01

    Tin doped indium oxide (In2O3:Sn) or indium tin oxide (ITO) thin films have been successfully deposited by the low cost spray-pyrolysis method. Low sheet resistance and high mobility films were obtained when the films were deposited at the substrate temperature of 793 K. The direct optical bandgaps for the films deposited at 793 (a) and 753 K (b) were found to be 3.46 and 3.40 eV, respectively. Similarly, the indirect bandgaps for a- and b-type films were found to be 3.0 and 2.75 eV, respectively. The Burstein-Moss shift was observed in the films. The refractive index (n) and extinction coefficient (k) were found to be in the range of 2.1 to 1.1 and 0.6 to 0.01, respectively. The various scattering mechanisms such as lattice, ionized impurity, neutral impurity, grain boundary and alloy scattering due to variation of theoretical mobilities with temperature are discussed, in order to compare experimental results. In the lattice scattering mechanism, the quantum size effect phenomena were employed to estimate the energy dilation (EI). The a-type films exhibited SnO2 as secondary phase whereas b-type films showed single phase In2O3:Sn with high sheet resistance. The lattice constants were found to be 10.16 and 10.09 Å for a- and b-type films, respectively.

  10. Luminescence properties of Eu-complex formations into ordered mesoporous silica particles obtained by the spray pyrolysis process

    NASA Astrophysics Data System (ADS)

    Rocha, Lucas A.; Freiria, Janaina do C.; Caiut, José Maurício A.; Ribeiro, Sidney J. L.; Messaddeq, Younes; Verelst, Marc; Dexpert-Ghys, Jeannette

    2015-08-01

    Ordered mesoporous, highly luminescent SiO2 particles have been synthesized by spray pyrolysis from solutions containing tetraethylorthosilicate (TEOS), Eu(NO3)3.6H2O, and cetyltrimethylammonium bromide (CTAB) as structure-directing agents. The 1,10-phenantroline (Phen) molecules were coordinated in a post-synthesis step by a simple wet impregnation method. In addition, other matrices were also prepared by the encapsulation of europium complex Eu(fod)3 (where fod = 6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionato) into mesoporous silica, and then the Phen molecules were encapsulated by different impregnation steps, after which the luminescence properties were investigated. The obtained materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder x-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Powders with polydisperse spherical grains were obtained, displaying an ordered hexagonal array of mesochannels. Luminescence results revealed that Phen molecules had been successfully coordinated as an additional ligand in the Eu(fod)3 complex into the channels of the mesoporous particles without disrupting the structure.

  11. Evolution of Zinc Oxide Nanostructures Grown on Graphene by Ultrasonic Spray Pyrolysis and Its Statistical Growth Modelling

    NASA Astrophysics Data System (ADS)

    Ali, Amgad Ahmed; Hashim, Abdul Manaf

    2015-11-01

    The evolution of zinc oxide nanostructures grown on graphene by alcohol-assisted ultrasonic spray pyrolysis was investigated. The evolution of structures is strongly depended on pyrolysis parameters, i.e., precursor molarity, precursor flow rate, precursor injection/deposition time, and substrate temperature. Field-effect scanning electron microscope analysis, energy dispersive X-ray spectroscopy, X-ray diffraction, and transmission electron microscopy were used to investigate the properties of the synthesized nanostructures and to provide evidence for the structural changes according to the changes in the pyrolysis parameters. The optimum parameters to achieve maximum density and well-defined hexagonally shaped nanorods were a precursor molarity of 0.2 M, an injection flow rate of 6 ml/min, an injection time of 10 min, and a substrate temperature of 250-355 °C. Based on the experimental results, the response surface methodology (RSM) was used to model and optimize the independent pyrolysis parameters using the Box-Behnken design. Here, the responses, i.e., the nanostructure density, size, and shape factor, are evaluated. All of the computations were performed using the Design-Expert software package. Analysis of variance (ANOVA) was used to evaluate the results of the model and to determine the significant values for the independent pyrolysis parameters. The evolution of zinc oxide (ZnO) structures are well explained by the developed modelling which confirms that RSM is a reliable tool for the modelling and optimization of the pyrolysis parameters and prediction of nanostructure sizes and shapes.

  12. Superior Na-ion storage properties of high aspect ratio SnSe nanoplates prepared by a spray pyrolysis process.

    PubMed

    Park, Gi Dae; Lee, Jong-Heun; Kang, Yun Chan

    2016-06-01

    SnSe nanoplates with thin and uniform morphology are prepared by one-pot spray pyrolysis, and are examined as anode materials for Na-ion batteries. During the spray pyrolysis process, metallic Se and Sn are prepared from SeO2 and SnO2, respectively, under a reducing atmosphere. Metallic Sn and metalloid Se, with melting points of 232 and 221 °C, respectively, form a melted Sn-Se mixture, which reacts exothermally to form SnSe nanocrystals. Several of these nanocrystals are grown simultaneously forming a micron-sized powder. Complete elimination of the excess amount of metalloid Se, by forming H2Se gas, results in aggregation-free SnSe nanoplates. The aspect ratio of these nanoplates is as high as 11.3. The discharge capacities for the SnSe nanoplates, prepared from spray solutions containing 100, 400, and 800% of the stoichiometric SeO2 content needed to form SnSe, are 407, 558, and 211 mA h g(-1), respectively, after 50 cycles at a constant current density of 0.3 A g(-1); their capacity retentions calculated from the second cycle onwards are 77, 100, and 60%, respectively. The phase pure SnSe nanoplates with a high aspect ratio show good cycling and rate performances for Na-ion storage. PMID:27240748

  13. Influence of solution deposition rate on properties of V2O5 thin films deposited by spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Abd-Alghafour, N. M.; Ahmed, Naser M.; Hassan, Zai; Mohammad, Sabah M.

    2016-07-01

    Vanadium oxide (V2O5) thin films were deposited on glass substrates by using a cost-efficient spray pyrolysis technique. The films were grown at 350° through thermal decomposition of VCl3 in deionized water with different solution spray rates. The high resolution X-ray diffraction results revealed the formation of nanocrystalline films having orthorhombic structures with preferential orientation along (101) direction. The spray rate influenced the surface morphology and crystallite size of the films. The crystallite size was found to increase whereas the micro-strain was decreased by increasing the spray deposition rates. The increase in crystallite size and decrease in the macrostrain resulted in an improvement in the films' crystallinity. The UV-Visible spectroscopy analysis indicated that the average transmittance of all films lies in the range 75-80 %. The band gap of V2O5 film was decreased from 2.65 to 2.46 eV with increase of the spray deposition rate from 5 ml/min to 10 ml/min. first, second, and third level headings (first level heading).

  14. Low Sheet Resistivity of Transparent Ga-Doped ZnO Film Grown by Atmospheric Spray Pyrolysis

    NASA Astrophysics Data System (ADS)

    Takemoto, Yujin; Oshima, Minoru; Yoshino, Kenji; Toyota, Kouji; Inaba, Koichiro; Haga, Ken-ichi; Tokudome, Koichi

    2011-08-01

    Ga-doped ZnO film on polyethylene terephthalate film was successfully grown at 150 °C by conventional atmospheric spray pyrolysis using diethylzinc-based solution. The samples had an average optical transmittance of more than 80% and were strongly a-axis orientated according to the result of optical transmittance and X-ray diffraction analyses, respectively. The n-type Ga-doped ZnO films had a low sheet resistivity of 250 Ω/square at an optimal Ga content of 1 at. % upon UV irradiation.

  15. Preparation of TiO 2 thin films by spray pyrolysis to be used as a photocatalyst

    NASA Astrophysics Data System (ADS)

    Abou-Helal, M. O.; Seeber, W. T.

    2002-07-01

    Transparent TiO 2 thin films were successfully prepared on glass substrates by using spray pyrolysis technique. The films are amorphous at deposition temperatures up to 450 °C. Starting at about 550 °C, the films are partially crystallized (anatase phase). The prepared films have good homogeneity with some porosity, which is suitable for the photocatalytic applications. By using high performance liquid chromatography (HPLC) technique, it was possible to prove the photocatalytic properties of TiO 2 thin films. The procedure uses basically the UV-catalytic transformation of methanol traces in water to methanal. Deposition parameters such as deposition temperature and spray time are varied to investigate the effect on the photocatalytic activity of the prepared films.

  16. Methods and apparatuses for deoxygenating biomass-derived pyrolysis oil

    DOEpatents

    Baird, Lance Awender; Brandvold, Timothy A.

    2015-10-20

    Embodiments of methods and apparatuses for deoxygenating a biomass-derived pyrolysis oil are provided. In one example, a method comprises the steps of separating a low-oxygen biomass-derived pyrolysis oil effluent into a low-oxygen-pyoil organic phase stream and an aqueous phase stream. Phenolic compounds are removed from the aqueous phase stream to form a phenolic-rich diluent recycle stream. A biomass-derived pyrolysis oil stream is diluted and heated with the phenolic-rich diluent recycle stream to form a heated diluted pyoil feed stream. The heated diluted pyoil feed stream is contacted with a deoxygenating catalyst in the presence of hydrogen to deoxygenate the heated diluted pyoil feed stream.

  17. One-Step Synthesis of Pt/Graphene Composites from Pt Acid Dissolved Ethanol via Microwave Plasma Spray Pyrolysis

    NASA Astrophysics Data System (ADS)

    Jo, Eun Hee; Chang, Hankwon; Kim, Sun Kyung; Choi, Ji-Hyuk; Park, Su-Ryeon; Lee, Chong Min; Jang, Hee Dong

    2016-09-01

    Pt nanoparticles-laden graphene (Pt/GR) composites were synthesized in the gas phase from a mixture of ethanol and Pt precursor by microwave plasma spray pyrolysis. The morphology of Pt/GR composites has the shape of wrinkled sheets of paper, while Pt nanoparticles (Pt NPs) that are less than 2.6 nm in the mean diameter are uniformly well deposited on the surface of GR sheets stacked in only three layers. The Pt/GR composite prepared with 20 wt% of Pt had the highest specific surface area and electrochemical surface area of up to 402 m2 g‑1 and 77 m2 g‑1 (Pt), respectively. In addition, the composite showed superior electrocatalytic activity compared with commercial Pt-carbon black. The excellent electrocatalytic activity was attributed to the high specific surface area and electrochemical surface area of the Pt/GR composite directly produced by microwave plasma spray pyrolysis. Thus, it is clearly expected that the Pt/GR composite is a promising material for DMFC catalysts.

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

    PubMed

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

    2012-05-11

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

  19. One-Step Synthesis of Pt/Graphene Composites from Pt Acid Dissolved Ethanol via Microwave Plasma Spray Pyrolysis.

    PubMed

    Jo, Eun Hee; Chang, Hankwon; Kim, Sun Kyung; Choi, Ji-Hyuk; Park, Su-Ryeon; Lee, Chong Min; Jang, Hee Dong

    2016-09-13

    Pt nanoparticles-laden graphene (Pt/GR) composites were synthesized in the gas phase from a mixture of ethanol and Pt precursor by microwave plasma spray pyrolysis. The morphology of Pt/GR composites has the shape of wrinkled sheets of paper, while Pt nanoparticles (Pt NPs) that are less than 2.6 nm in the mean diameter are uniformly well deposited on the surface of GR sheets stacked in only three layers. The Pt/GR composite prepared with 20 wt% of Pt had the highest specific surface area and electrochemical surface area of up to 402 m(2) g(-1) and 77 m(2) g(-1) (Pt), respectively. In addition, the composite showed superior electrocatalytic activity compared with commercial Pt-carbon black. The excellent electrocatalytic activity was attributed to the high specific surface area and electrochemical surface area of the Pt/GR composite directly produced by microwave plasma spray pyrolysis. Thus, it is clearly expected that the Pt/GR composite is a promising material for DMFC catalysts.

  20. One-Step Synthesis of Pt/Graphene Composites from Pt Acid Dissolved Ethanol via Microwave Plasma Spray Pyrolysis

    PubMed Central

    Jo, Eun Hee; Chang, Hankwon; Kim, Sun Kyung; Choi, Ji-Hyuk; Park, Su-Ryeon; Lee, Chong Min; Jang, Hee Dong

    2016-01-01

    Pt nanoparticles-laden graphene (Pt/GR) composites were synthesized in the gas phase from a mixture of ethanol and Pt precursor by microwave plasma spray pyrolysis. The morphology of Pt/GR composites has the shape of wrinkled sheets of paper, while Pt nanoparticles (Pt NPs) that are less than 2.6 nm in the mean diameter are uniformly well deposited on the surface of GR sheets stacked in only three layers. The Pt/GR composite prepared with 20 wt% of Pt had the highest specific surface area and electrochemical surface area of up to 402 m2 g−1 and 77 m2 g−1 (Pt), respectively. In addition, the composite showed superior electrocatalytic activity compared with commercial Pt-carbon black. The excellent electrocatalytic activity was attributed to the high specific surface area and electrochemical surface area of the Pt/GR composite directly produced by microwave plasma spray pyrolysis. Thus, it is clearly expected that the Pt/GR composite is a promising material for DMFC catalysts. PMID:27622908

  1. Low Temperature Synthesis of Fluorine-Doped Tin Oxide Transparent Conducting Thin Film by Spray Pyrolysis Deposition.

    PubMed

    Ko, Eun-Byul; Choi, Jae-Seok; Jung, Hyunsung; Choi, Sung-Churl; Kim, Chang-Yeoul

    2016-02-01

    Transparent conducting oxide (TCO) is widely used for the application of flat panel display like liquid crystal displays and plasma display panel. It is also applied in the field of touch panel, solar cell electrode, low-emissivity glass, defrost window, and anti-static material. Fluorine-doped tin oxide (FTO) thin films were fabricated by spray pyrolysis of ethanol-added FTO precursor solutions. FTO thin film by spray pyrolysis is very much investigated and normally formed at high temperature, about 500 degrees C. However, these days, flexible electronics draw many attentions in the field of IT industry and the research for flexible transparent conducting thin film is also required. In the industrial field, indium-tin oxide (ITO) film on polymer substrate is widely used for touch panel and displays. In this study, we investigated the possibility of FTO thin film formation at relatively low temperature of 250 degrees C. We found out that the control of volume of input precursor and exhaust gases could make it possible to form FTO thin film with a relatively low electrical resistance, less than 100 Ohm/sq and high optical transmittance about 88%. PMID:27433704

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

    PubMed

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

    2012-05-11

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

  3. Low Temperature Synthesis of Fluorine-Doped Tin Oxide Transparent Conducting Thin Film by Spray Pyrolysis Deposition.

    PubMed

    Ko, Eun-Byul; Choi, Jae-Seok; Jung, Hyunsung; Choi, Sung-Churl; Kim, Chang-Yeoul

    2016-02-01

    Transparent conducting oxide (TCO) is widely used for the application of flat panel display like liquid crystal displays and plasma display panel. It is also applied in the field of touch panel, solar cell electrode, low-emissivity glass, defrost window, and anti-static material. Fluorine-doped tin oxide (FTO) thin films were fabricated by spray pyrolysis of ethanol-added FTO precursor solutions. FTO thin film by spray pyrolysis is very much investigated and normally formed at high temperature, about 500 degrees C. However, these days, flexible electronics draw many attentions in the field of IT industry and the research for flexible transparent conducting thin film is also required. In the industrial field, indium-tin oxide (ITO) film on polymer substrate is widely used for touch panel and displays. In this study, we investigated the possibility of FTO thin film formation at relatively low temperature of 250 degrees C. We found out that the control of volume of input precursor and exhaust gases could make it possible to form FTO thin film with a relatively low electrical resistance, less than 100 Ohm/sq and high optical transmittance about 88%.

  4. One-Step Synthesis of Pt/Graphene Composites from Pt Acid Dissolved Ethanol via Microwave Plasma Spray Pyrolysis.

    PubMed

    Jo, Eun Hee; Chang, Hankwon; Kim, Sun Kyung; Choi, Ji-Hyuk; Park, Su-Ryeon; Lee, Chong Min; Jang, Hee Dong

    2016-01-01

    Pt nanoparticles-laden graphene (Pt/GR) composites were synthesized in the gas phase from a mixture of ethanol and Pt precursor by microwave plasma spray pyrolysis. The morphology of Pt/GR composites has the shape of wrinkled sheets of paper, while Pt nanoparticles (Pt NPs) that are less than 2.6 nm in the mean diameter are uniformly well deposited on the surface of GR sheets stacked in only three layers. The Pt/GR composite prepared with 20 wt% of Pt had the highest specific surface area and electrochemical surface area of up to 402 m(2) g(-1) and 77 m(2) g(-1) (Pt), respectively. In addition, the composite showed superior electrocatalytic activity compared with commercial Pt-carbon black. The excellent electrocatalytic activity was attributed to the high specific surface area and electrochemical surface area of the Pt/GR composite directly produced by microwave plasma spray pyrolysis. Thus, it is clearly expected that the Pt/GR composite is a promising material for DMFC catalysts. PMID:27622908

  5. Liquid-feed flame spray pyrolysis synthesis of oxide nanopowders for the processing of ceramic composites

    NASA Astrophysics Data System (ADS)

    Taylor, Nathan John

    In the liquid-feed flame spray pyrolysis (LF-FSP) process, alcohol solutions of metalloorganic precursors are aerosolized by O2 and combusted. The metal oxide combustion products are rapidly quenched (< 10 ms) from flame temperatures of 1500°C to temperatures < 400° C, limiting particle growth. The resulting nanopowders are typically agglomerated but unaggregated. Here, we demonstrate two processing approaches to dense materials: nanopowders with the exact composition, and mixed single metal oxide nanopowders. The effect of the initial degree of phase separation on the final microstructures was determined by sintering studies. Our first studies included the production of yttrium aluminum garnet, Y3Al5O12 (YAG), tubes which we extruded from a thermoplastic/ceramic blend. At equivalent final densities, we found finer grain sizes in the from the mixed Y2O3 and Al2 O3 nanopowders, which was attributed to densification occurring before full transformation to the YAG phase. The enhanced densification in production of pure YAG from the reactive sintering process led us to produce composites in the YAG/alpha-Al 2O3 system. Finally, a third Y2O3 stabilized ZrO2 (YSZ) phase was added to further refine grain sizes using the same two processing approaches. In a separate study, single-phase metastable Al2O3 rich spinels with the composition MO•3Al 2O3 where M = Mg, Ni, and Co were sintered to produce dense MAl2O4/alpha-Al2O3 composites. All of these studies provide a test of the bottom-up approach; that is, how the initial length scale of mixing affects the final composite microstructure. Overall, the length scale of mixing is highly dependent upon the specific oxide composites studied. This work provides a processing framework to be adopted by other researchers to further refine microstructural size. LF-FSP flame temperatures were mapped using different alcohols with different heats of combustion: methanol, ethanol, 1-propanol, and n-butanol. The effect of different

  6. Superior Na-ion storage properties of high aspect ratio SnSe nanoplates prepared by a spray pyrolysis process

    NASA Astrophysics Data System (ADS)

    Park, Gi Dae; Lee, Jong-Heun; Kang, Yun Chan

    2016-06-01

    SnSe nanoplates with thin and uniform morphology are prepared by one-pot spray pyrolysis, and are examined as anode materials for Na-ion batteries. During the spray pyrolysis process, metallic Se and Sn are prepared from SeO2 and SnO2, respectively, under a reducing atmosphere. Metallic Sn and metalloid Se, with melting points of 232 and 221 °C, respectively, form a melted Sn-Se mixture, which reacts exothermally to form SnSe nanocrystals. Several of these nanocrystals are grown simultaneously forming a micron-sized powder. Complete elimination of the excess amount of metalloid Se, by forming H2Se gas, results in aggregation-free SnSe nanoplates. The aspect ratio of these nanoplates is as high as 11.3. The discharge capacities for the SnSe nanoplates, prepared from spray solutions containing 100, 400, and 800% of the stoichiometric SeO2 content needed to form SnSe, are 407, 558, and 211 mA h g-1, respectively, after 50 cycles at a constant current density of 0.3 A g-1 their capacity retentions calculated from the second cycle onwards are 77, 100, and 60%, respectively. The phase pure SnSe nanoplates with a high aspect ratio show good cycling and rate performances for Na-ion storage.SnSe nanoplates with thin and uniform morphology are prepared by one-pot spray pyrolysis, and are examined as anode materials for Na-ion batteries. During the spray pyrolysis process, metallic Se and Sn are prepared from SeO2 and SnO2, respectively, under a reducing atmosphere. Metallic Sn and metalloid Se, with melting points of 232 and 221 °C, respectively, form a melted Sn-Se mixture, which reacts exothermally to form SnSe nanocrystals. Several of these nanocrystals are grown simultaneously forming a micron-sized powder. Complete elimination of the excess amount of metalloid Se, by forming H2Se gas, results in aggregation-free SnSe nanoplates. The aspect ratio of these nanoplates is as high as 11.3. The discharge capacities for the SnSe nanoplates, prepared from spray solutions

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

    SciTech Connect

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

    2015-01-14

    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.

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

    ERIC Educational Resources Information Center

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

    2007-01-01

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

  9. Effect of annealing on the properties of nanocrystalline CuInSSe thin films deposited by spray pyrolysis

    SciTech Connect

    Shrotriya, Vipin Rajaram, P.

    2015-08-28

    The effect of annealing CuInSSe thin films, which were grown on glass substrates using the spray pyrolysis technique from spray solutions having S/Se ionic ratio 0.6, were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and optical transmission measurements. The CuInSSe films were co-deposited from an aqueous solution containing CuCl{sub 2}, InCl{sub 3}, thiourea and SeO{sub 2}. EDC was used as a complexing agent and films were deposited at the constant temperature 300°C. Post annealing (at 350°C) was used to improve the structural, morphological and optical properties of CuInSSe thin films. From the results, it is found that the films are single phase, p-type in conductivity having the chalcopyrite structure. From the Scherrer formula the average size of the films was found to be in the range (15-28) nm. Optical studies show that the optical band gap value increases slightly from 1.35 eV to 1.37 eV with annealing for films grown from spray solutions having S/Se ionic ratio 0.6.

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

    DOEpatents

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

    2013-08-27

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

  11. 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)

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

    2014-02-01

    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.

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

    SciTech Connect

    Martinez, H.M.; Torres, J.; Lopez Carreno, L.D.; Rodriguez-Garcia, M.E.

    2013-01-15

    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.

  13. Investigations of superparamagnetism in magnesium ferrite nano-sphere synthesized by ultrasonic spray pyrolysis technique for hyperthermia application

    NASA Astrophysics Data System (ADS)

    Das, Harinarayan; Sakamoto, Naonori; Aono, Hiromichi; Shinozaki, Kazuo; Suzuki, Hisao; Wakiya, Naoki

    2015-10-01

    In this paper, we present the synthesized of magnesium ferrite (MgFe2O4) nano-spheres by a single-step ultrasonic spray pyrolysis (USP) technique from the aqueous metal nitrate precursor solution without any organic additives or post-annealing processes. The effects of different pyrolysis temperatures on the particles size, morphology and their superparamagnetic behavior have been investigated to evaluate the heat generation efficiency in an AC magnetic field. The X-ray powder diffraction spectra of MgFe2O4 nano-spheres synthesized at the pyrolysis temperatures of 600, 700, 800 and 900 °C exhibited single phase cubic structure and obtained mean crystallite size (primary particles) of 4.05, 9.6, 15.97 and 31.48 nm, respectively. Transmission electron microscopy (TEM) confirms that the particles consisted of aggregates of the primary crystallite had densely congested spherical morphology with extremely smooth surface appearance. Field emission electron microscopy (FESEM) reveals that the shape and size of the nano-spheres (secondary particles) does not change significantly but the degree of agglomeration between the secondary particles was reduced with increasing the pyrolysis temperature. The average size and size distribution of nano-spheres measured using electrophoretic scattering photometer have found very low polydispersity index (PDI) for all samples. The field dependent magnetization studies indicated superparamagnetic nature for the particles having crystallite size i.e. 4.05 and 9.6 nm and exhibited ferromagnetic nature for 15.97 and 31.48 nm. It is also demonstrated that, as the pyrolysis temperature increases, the saturation magnetization of the MgFe2O4 nanopowders increases due to enhancement of crystallites. The shift in Curie temperature is well described by the finite-size scaling formula. The magnetically loss heating values of selected samples in crystallite size of 9.6 and 15.97 nm were investigated by measuring the time dependent temperature

  14. Effect of catalytic pyrolysis conditions using pulse current heating method on pyrolysis products of wood biomass.

    PubMed

    Honma, Sensho; Hata, Toshimitsu; Watanabe, Takashi

    2014-01-01

    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.

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

    PubMed Central

    Honma, Sensho; Hata, Toshimitsu; Watanabe, Takashi

    2014-01-01

    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

  16. Effect of catalytic pyrolysis conditions using pulse current heating method on pyrolysis products of wood biomass.

    PubMed

    Honma, Sensho; Hata, Toshimitsu; Watanabe, Takashi

    2014-01-01

    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

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

    NASA Astrophysics Data System (ADS)

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

    2013-09-01

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

  18. Selectivity Enhancement by Using Double-Layer MOX-Based Gas Sensors Prepared by Flame Spray Pyrolysis (FSP)

    PubMed Central

    Rebholz, Julia; Grossmann, Katharina; Pham, David; Pokhrel, Suman; Mädler, Lutz; Weimar, Udo; Barsan, Nicolae

    2016-01-01

    Here we present a novel concept for the selective recognition of different target gases with a multilayer semiconducting metal oxide (SMOX)-based sensor device. Direct current (DC) electrical resistance measurements were performed during exposure to CO and ethanol as single gases and mixtures of highly porous metal oxide double- and single-layer sensors obtained by flame spray pyrolysis. The results show that the calculated resistance ratios of the single- and double-layer sensors are a good indicator for the presence of specific gases in the atmosphere, and can constitute some building blocks for the development of chemical logic devices. Due to the inherent lack of selectivity of SMOX-based gas sensors, such devices could be especially relevant for domestic applications. PMID:27608028

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

    PubMed

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

    2014-12-18

    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 α-Bi2Mo3O12 and γ-Bi2MoO6, FSP gave direct access to the metastable β-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 β-phase was stable up to 400 °C and showed superior catalytic performance compared to α- and γ-phases in selective oxidation of propylene to acrolein at temperatures relevant for industrial applications (360 °C). PMID:25350295

  20. Electronic properties of ZnO field-effect transistors fabricated by spray pyrolysis in ambient air

    NASA Astrophysics Data System (ADS)

    Adamopoulos, George; Bashir, Aneeqa; Wöbkenberg, Paul H.; Bradley, Donal D. C.; Anthopoulos, Thomas D.

    2009-09-01

    We report the application of spray pyrolysis (SP) for the deposition of high quality zinc oxide (ZnO) films and the fabrication of thin-film transistors. The chemical, structural, optical, and electronic properties of as-deposited ZnO films are studied using infrared spectroscopy, atomic force microscopy, UV-visible spectroscopic ellipsometry, and field-effect measurements. SP ZnO films are found to be uniform and polycrystalline with a band gap of 3.32 eV. ZnO transistors exhibit n-channel characteristics with electron mobility in the range 10-22 cm2/Vs. Device performance is found to depend on the work function of source/drain metal electrodes and on the device architecture employed.

  1. Ethylene glycol assisted spray pyrolysis for the synthesis of hollow BaFe12O19 spheres

    SciTech Connect

    Xu, X; Park, J; Hong, YK; Lane, AM

    2015-04-01

    Hollow spherical BaFe12O19 particles were synthesized by spray pyrolysis from a solution containing ethylene glycol (EG) and precursors at 1000 degrees C. The effects of EG concentration on particle morphology, crystallinity and magnetic properties were investigated. The hollow spherical particles were found to consist of primary particles, and higher EG concentration led to a bigger primary particle size. EG concentration did not show much effect on the hollow particle size. Better crystallinity and higher magnetic coercivity were obtained with higher EG concentration, which is attributed to further crystallization with the heat produced from EG combustion. Saturation magnetization (emu/g) decreased with increasing EG concentration due to residual carbon from EG incomplete combustion, contributing as a non-magnetic phase to the particles. Published by Elsevier B.V.

  2. Selectivity Enhancement by Using Double-Layer MOX-Based Gas Sensors Prepared by Flame Spray Pyrolysis (FSP).

    PubMed

    Rebholz, Julia; Grossmann, Katharina; Pham, David; Pokhrel, Suman; Mädler, Lutz; Weimar, Udo; Barsan, Nicolae

    2016-01-01

    Here we present a novel concept for the selective recognition of different target gases with a multilayer semiconducting metal oxide (SMOX)-based sensor device. Direct current (DC) electrical resistance measurements were performed during exposure to CO and ethanol as single gases and mixtures of highly porous metal oxide double- and single-layer sensors obtained by flame spray pyrolysis. The results show that the calculated resistance ratios of the single- and double-layer sensors are a good indicator for the presence of specific gases in the atmosphere, and can constitute some building blocks for the development of chemical logic devices. Due to the inherent lack of selectivity of SMOX-based gas sensors, such devices could be especially relevant for domestic applications. PMID:27608028

  3. Impact of active layer thickness in thin-film transistors based on Zinc Oxide by ultrasonic spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Dominguez, Miguel A.; Flores, Francisco; Luna, Adan; Martinez, Javier; Luna-Lopez, Jose A.; Alcantara, Salvador; Rosales, Pedro; Reyes, Claudia; Orduña, Abdu

    2015-07-01

    In this work, the preparation of Zinc Oxide (ZnO) films by ultrasonic spray pyrolysis at low-temperature and its application in thin-film transistors (TFTs) are presented, as well, the impact of the active layer thickness and gate dielectric thickness in the electrical performance of the ZnO TFTs. A thinner active layer resulted in better transfer characteristics such as higher on/off-current ratio, while a thicker active layer resulted in better output characteristics. The ZnO films were deposited from 0.2 M precursor solution of Zinc acetate in methanol, using air as carrier gas on a hotplate at 200 °C. The ZnO films obtained at 200 °C were characterized by optical transmittance, Photoluminescence spectroscopy and X-ray diffraction.

  4. Effect of In doping on the properties and antibacterial activity of ZnO films prepared by spray pyrolysis.

    PubMed

    Manoharan, C; Pavithra, G; Dhanapandian, S; Dhamodharan, P

    2015-01-01

    Pure and In-doped ZnO thin films were deposited onto glass substrates by spray pyrolysis technique. XRD results showed that all films were polycrystalline in nature with the wurzite structure. A change in preferential orientation from (002) to (101) plane was observed with increase in content of Indium. A reduce in crystallite size was observed with increase of In content. The small sized grains with the porous nature of the film was observed from SEM analysis. AFM study depicted polycrystalline nature and uniformly distributed grains with small pores in the doped film. A decrease in band gap was noticed with increase in In content. The absence of green emission in PL spectra indicated the decreased oxygen defects. The decrease in the resistivity with increase of Hall mobility was noted for the doped film. A better antibacterial activity was observed against Staphylococcus aureus by doped ZnO thin film. PMID:25997176

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

    SciTech Connect

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

    2014-01-28

    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.

  6. Photoluminescence of (YGd)2O3:Eu phosphors produced by nanoparticle-seeded flame-assisted spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Kubrin, R.; Huang, J.; Moglia, F.; Petermann, K.; Bauhofer, W.

    2011-05-01

    We report on synthesis of europium-doped (Y1-xGdx)2O3 by flame-assisted spray py-rolysis in premixed propane/air flames. Phosphor powders with an average particle size on the order of 0.5 μm were obtained from 0.2 M aqueous solutions of the corresponding metal salts. Relative concentration of gadolinium (x) was varied in the range 0 to 1. For excitation at a wavelength of 254 nm, the highest intensity of photoluminescence was achieved for x = 0.2 (110% of brightness of the samples without gadolinia). Doping pure yttria and gadolinia with nanoparticles of Y2O3:Eu (dBET = 24 nm) was tested. Addition of nanoseeds (up to 50 mol.% in the obtained powders) noticeably decreased surface roughness of phosphor particles.

  7. Spin wave study and optical properties in Fe-doped ZnO thin films prepared by spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Lmai, F.; Moubah, R.; El Amiri, A.; Abid, Y.; Soumahoro, I.; Hassanain, N.; Colis, S.; Schmerber, G.; Dinia, A.; Lassri, H.

    2016-07-01

    We investigate the magnetic and optical properties of Zn1-xFexO (x = 0, 0.03, 0.05, and 0.07) thin films grown by spray pyrolysis technique. The magnetization as a function of temperature [M (T)] shows a prevailing paramagnetic contribution at low temperature. By using spin wave theory, we separate the M (T) curve in two contributions: one showing intrinsic ferromagnetism and one showing a purely paramagnetic behavior. Furthermore, it is shown that the spin wave theory is consistent with ab-initio calculations only when oxygen vacancies are considered, highlighting the key role played by structural defects in the mechanism driving the observed ferromagnetism. Using UV-visible measurements, the transmittance, reflectance, band gap energy, band tail, dielectric coefficient, refractive index, and optical conductivity were extracted and related to the variation of the Fe content.

  8. Low-temperature spray-pyrolysis of FeS2 films and their electrical and optical properties

    NASA Astrophysics Data System (ADS)

    Orletskii, I. G.; Mar'yanchuk, P. D.; Maistruk, E. V.; Solovan, M. N.; Brus, V. V.

    2016-01-01

    Iron disulfide (FeS2) films with a wide range of electrical resistivities 100 Ω cm ⩽ ρ ⩽ 800 kΩ cm, a high adhesion to the substrate, and a resistance to aggressive media have been prepared by the spray pyrolysis of aqueous solutions of the salts FeCl3 · 6H2O and (NH2)2CS at low temperatures in the range 250°C ⩽ T S ⩽ 400°C. It has been found that the FeS2 films have a high transmittance T ≈ 60-70% and are characterized by a sharp transmission edge. It has been shown that the optical band gap for direct ( E g op = 2.19-2.78 eV) and indirect ( E g 'op = 1.26-1.36 eV) optical transitions depends on the conditions of film preparation.

  9. Apparatuses and methods for deoxygenating biomass-derived pyrolysis oil

    SciTech Connect

    Kalnes, Tom N.

    2015-12-29

    Apparatuses and methods for deoxygenating a biomass-derived pyrolysis oil are provided herein. In one example, the method comprises of dividing a feedstock stream into first and second feedstock portions. The feedstock stream comprises the biomass-derived pyrolysis oil and has a temperature of about 60.degree. C. or less. The first feedstock portion is combined with a heated organic liquid stream to form a first heated diluted pyoil feed stream. The first heated diluted pyoil feed stream is contacted with a first deoxygenating catalyst in the presence of hydrogen to form an intermediate low-oxygen pyoil effluent. The second feedstock portion is combined with the intermediate low-oxygen pyoil effluent to form a second heated diluted pyoil feed stream. The second heated diluted pyoil feed stream is contacted with a second deoxygenating catalyst in the presence of hydrogen to form additional low-oxygen pyoil effluent.

  10. Elaboration of Ti{sub 0.5}Pb{sub 0.5}Sr{sub 2}CaCu{sub 2}O{sub x} superconducting phases by an ultrasonic spray-pyrolysis process

    SciTech Connect

    Abraham, R.; Guenard, F.; Lebbou, K.; Trosset, S.; Cohen-Adad, M.T.; Jorda, J.L.; Couach, M.

    1998-02-01

    An ultrasonic spray-pyrolysis process has been used to prepare a homogeneous T{sub 10.5}Pb{sub 0.5}Sr{sub 2}CaCu{sub 2}O{sub x} high-temperature superconductor. Depending on experimental conditions, the grain morphology changes from platelet to cauliflower-like, contrary to the three copper layers series. The (Tl/Pb)-Sr-1212 phase has remarkable stability and does not decompose before melting. The critical temperature onset, about 80 K, is similar to that for samples prepared by the usual sintering methods.

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

    SciTech Connect

    Ortel, Marlis; Balster, Torsten; Wagner, Veit

    2013-12-21

    Zinc oxide thin film transistors (TFTs) deposited by continuous and pulsed spray pyrolysis were investigated to analyze process kinetics which make reduction of process temperature possible. Thus, fluid mechanics, chemical composition, electrical performance, and deposition and annealing temperature were systematically analyzed. It was found that ZnO layers continuously deposited at 360 °C contained zinc oxynitrides, CO{sub 3}, and hydro carbonate groups from pyrolysis of basic zinc acetate. Statistically, every second wurtzite ZnO unit cell contained an impurity atom. The purity and performance of the ZnO-TFTs increased systematically with increasing deposition temperature due to an improved oxidation processes. At 500 °C the zinc to oxygen ratio exceeded a high value of 0.96. Additionally, the ZnO film was not found to be in a stabilized state after deposition even at high temperatures. Introducing additional subsequent annealing steps stabilizes the film and allows the reduction of the overall thermal stress to the substrate. Further improvement of device characteristics was obtained by pulsed deposition which allowed a more effective transport of the by-products and oxygen. A significant reduction of the deposition temperature by 140 °C was achieved compared to the same performance as in continuous deposition mode. The trap density close to the Fermi energy could be reduced by a factor of two to 4 × 10{sup 17} eV{sup −1} cm{sup −3} due to the optimized combustion process on the surface. The optimization of the deposition processes made the fabrication of TFTs with excellent performance possible. The mobility was high and exceeded 12 cm{sup 2}/V s, the subthreshold slope was 0.3 V dec{sup −1}, and an on-set close to the ideal value of 0 V was achieved.

  12. Novel mechanism for high speed growth of transparent and conducting tin oxide thin films by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Kameswara Rao, L.; Vinni, V.

    1993-08-01

    A novel mechanism is proposed for efficient manipulation of transport forces acting on the droplets during spray pyrolytic deposition of thin films. A ``burst mode'' technique of spraying is used to adjust the deposition conditions so as to transport the droplets under the new mechanism. Transparent, conducting thin films of undoped tin oxide prepared by this method showed significant improvement in growth rate. The films are found to be of fairly good quality with optical transmission of 82% and sheet resistance of 35 Ω/⧠. The films are chemically homogeneous and grow preferentially along <200> direction.

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

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

    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.

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

    PubMed

    Hu, Zhifeng; Ma, Xiaoqian; Li, Longjun

    2013-07-01

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

  15. Nanofiber spraying method using a supplementary electrode

    NASA Astrophysics Data System (ADS)

    Kim, GeunHyung; Kim, WanDoo

    2006-07-01

    Using a supplementary electrode, electrospun poly(ɛ-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.

  16. Ni-SiO₂ catalysts for the carbon dioxide reforming of methane: varying support properties by flame spray pyrolysis.

    PubMed

    Lovell, Emma C; Scott, Jason; Amal, Rose

    2015-01-01

    Silica particles were prepared by flame spray pyrolysis (FSP) as a support for nickel catalysts. The impact of precursor feed rate (3, 5 and 7 mL/min) during FSP on the silica characteristics and the ensuing effect on catalytic performance for the carbon dioxide, or dry, reforming of methane (DRM) was probed. Increasing the precursor feed rate: (i) progressively lowered the silica surface area from ≈340 m2/g to ≈240 m2/g; (ii) altered the silanol groups on the silica surface; and (iii) introduced residual carbon-based surface species to the sample at the highest feed rate. The variations in silica properties altered the (5 wt %) nickel deposit characteristics which in turn impacted on the DRM reaction. As the silica surface area increased, the nickel dispersion increased which improved catalyst performance. The residual carbon-based species also appeared to improve nickel dispersion, and in turn catalyst activity, although not to the same extent as the change in silica surface area. The findings illustrate both the importance of silica support characteristics on the catalytic performance of nickel for the DRM reaction and the capacity for using FSP to control these characteristics. PMID:25774491

  17. Opto-structural, electrical and electrochromic properties of crystalline nickel oxide thin films prepared by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Mahmoud, S. A.; Akl, A. A.; Kamal, H.; Abdel-Hady, K.

    2002-02-01

    Polycrystalline nickel oxide films with preferential growth along (1 1 1) plane were deposited onto glass substrates, maintained at 350°C, by the spray pyrolysis technique using nickel chloride as starting solution. The effect of solution concentration on their structural, electrical, and optical properties was studied. Using X-ray diffraction, the structural characteristics have been studied and due to the high degree of preferred orientation, Voigt analysis of single reflection was used to determine the microstructural properties (crystallite size and microstrain). The refractive index n and the extinction coefficient k have been computed from the corrected transmittance and reflectance measurements over the spectral range 300-2400 nm. Analysis of the absorption versus photon energy curves revealed a direct transition with optical band gap, Eg, of 3.6 eV and indirect transition within the range 3.97-3.75 eV as solution molarity increases from 0.05 to 0.3 M. The electrochromic behaviour of polycrystalline nickel oxide film were investigated by means of cyclic voltametry in 1 M KOH aqueous solution. Cycling showed significant increase in solar optical modulation reaching a value of 0.23 after 150 cycles.

  18. Influence of concentration and volume of precursor on the electrochemical properties of vanadium oxide thin films prepared by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Ingole, R. S.; Fugare, B. Y.; Lokhande, B. J.

    2016-04-01

    Vanadium oxide (V2O5) thin films have been prepared by spray pyrolysis using different concentrations and volumes of precursor solution via aqueous route at 673K deposition temperature. The influences of concentration and volume on the structural, morphological and electrochemical properties of the deposited samples are studied well. X - ray diffraction study shows orthorhombic crystal structure with V2O5 phase, confirmed by FTIR spectroscopy. Scanning electron microscopy shows granular, homogeneous and dense surface morphology. Cyclic voltammetery of all samples carried at all scan rates. Samples prepared using 0.05M, 40 ml of precursor solution shows highest specific capacitance 428.25 F/gm at 5 mV/s, Charge discharge behavior exhibits specific energy 18.73 Wh/kg, specific power 36.00 kW/kg, columbic efficiency 87.50 %. Impedance spectroscopy study was carried in the frequency range 1mHz - 1MHz, reveals pseudocapacitive behavior of the electrode exhibiting internal resistance 1.34 ohm.

  19. Optical properties of undoped and tin-doped nanostructured In2O3 thin films deposited by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Fellahi, Nabil; Addou, Mohammed; Kachouane, Amina; El Jouad, Mohamed; Sofiani, Zouhair

    2016-05-01

    Tin-doped indium oxide (In2O3:Sn) thin films in different concentrations (Sn = 0, 3, 5, 8 at.%) were deposited by reactive chemical pulverisation spray pyrolysis on heated glass substrates at 500 °C. The effect of the tin dopant on the nonlinear optical properties was investigated using X-ray diffraction, transmission, electrical resistivity and third harmonic generation (THG). All films were polycrystalline, and crystallised in a cubic structure with a preferential orientation along the (400) direction. The Sn (5 at.%) doped In2O3 thin films exhibited a lower resistivity of 3 × 10-4 Ω cm, and higher transmission in the visible region of about 94%. Optical parameters, such as the extinction coefficient (k), refractive index (n) and energy band gap (Eg), were also studied to show the composition-dependence of tin-doped indium oxide films. The nonlinear properties of the In2O3:Sn thin films have been found to be influenced by doping concentration, and the best value of χ(3) = 3 × 10-11 (esu) was found for the 5 at.% doped sample. Contribution to the topical issue "Materials for Energy Harvesting, Conversion and Storage (ICOME 2015) - Elected submissions", edited by Jean-Michel Nunzi, Rachid Bennacer and Mohammed El Ganaoui

  20. Ni-SiO₂ catalysts for the carbon dioxide reforming of methane: varying support properties by flame spray pyrolysis.

    PubMed

    Lovell, Emma C; Scott, Jason; Amal, Rose

    2015-01-01

    Silica particles were prepared by flame spray pyrolysis (FSP) as a support for nickel catalysts. The impact of precursor feed rate (3, 5 and 7 mL/min) during FSP on the silica characteristics and the ensuing effect on catalytic performance for the carbon dioxide, or dry, reforming of methane (DRM) was probed. Increasing the precursor feed rate: (i) progressively lowered the silica surface area from ≈340 m2/g to ≈240 m2/g; (ii) altered the silanol groups on the silica surface; and (iii) introduced residual carbon-based surface species to the sample at the highest feed rate. The variations in silica properties altered the (5 wt %) nickel deposit characteristics which in turn impacted on the DRM reaction. As the silica surface area increased, the nickel dispersion increased which improved catalyst performance. The residual carbon-based species also appeared to improve nickel dispersion, and in turn catalyst activity, although not to the same extent as the change in silica surface area. The findings illustrate both the importance of silica support characteristics on the catalytic performance of nickel for the DRM reaction and the capacity for using FSP to control these characteristics.

  1. Thickness-Dependent Structural and Optoelectronic Properties of In2O3 Films Prepared by Spray Pyrolysis Technique

    NASA Astrophysics Data System (ADS)

    Khan, M. A. Majeed; Khan, Wasi

    2016-08-01

    In this work, nanostructured In2O3 thin films with thickness in the range of 40-160 nm were deposited on glass substrates by the chemical spray pyrolysis technique. The microstructural, surface morphology and optical properties were investigated as a function of film thickness through x-ray diffraction, scanning electron microscopy equipped with energy dispersive spectroscopy, atomic force microscopy, Raman spectroscopy, UV-visible spectroscopy and photoluminescence measurements. The x-ray diffraction analysis showed that the deposited films were polycrystalline in nature with a cubic structure having (222) as preferred orientation. The morphological analyses of the samples exhibited uniform and smooth surface of the films with systematical increments in the surface roughness with increasing film thickness. The grain size increased from 9 nm to 13 nm with increasing film thickness. Raman spectroscopy has been employed to study the crystalline quality and the structural disorder of the films. A blue-shift in the energy band gap ( E g) from 3.74 eV to 3.98 eV was observed with the increase of film thickness. Moreover, photoluminescence peaks of the In2O3 films appeared at 443 nm and 527 nm for all films. The thickness had a substantial influence on the microstructural and optical properties as well as on the luminescence intensity of the films. The strategy presented here indicates that the prepared films could be suitable candidates for optoelectronic device applications.

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

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

    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 β-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.

  3. High-performance p-n heterojunction photodetectors based on V2O5 nanorods by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Abd-Alghafour, N. M.; Ahmed, Naser. M.; Hassan, Z.; Bououdina, M.

    2016-09-01

    V2O5 heterojunction photodetector was fabricated onto Si(100) substrate using spray pyrolysis technique. Vanadium chloride (VCl3) precursor with 0.05 M concentration was used to prepare V2O5 thin film. The structural, morphological, and optical properties of V2O5 thin film were investigated. High-resolution X-ray diffraction analysis confirmed the formation of V2O5 thin film with a preferred orientation along (110) plane. Morphological observations using field emission scanning electron microscope displayed the formation of thin film with rod-like nanostructure. The optical properties examined by photoluminescence spectroscopy indicated a high-intensity visible peak centered around 530 nm. Current-voltage ( I- V) characteristics of the fabricated device under visible light exhibited low dark current and high photocurrent of 540 μA at 3 V bias voltages. Upon exposure to 560 nm visible light (24 mW/cm2) at 3 V, the device displayed a good sensitivity of 20.16 × 102. In addition, the internal gain of the photodiode was 21.16, and the photoresponse peak was 50 mA/W. The rise and recovery times of the photodiode were calculated to be 0.127 and 0.526 s under visible light (560 nm, 24 mW/cm2), respectively, at 3 V.

  4. Nano porous Al2O3-TiO2 thin film based humidity sensor prepared by spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Chandrashekara, H. D.; Angadi, Basavaraj; Ravikiran, Y. T.; Poornima, P.; Shashidhar, R.; Murthy, L. C. S.

    2016-05-01

    The nano porous surface structured TiO2 and Al2O3-TiO2 thin films were prepared using spray pyrolysis technique at 350°C. The XRD pattern of Al2O3-TiO2 film shows anatase phase and mixed phase of Al2TiO5. The surface morphology of films show a uniformly distributed nano porous structure. The elemental analysis through EDAX shows good stoichiometry. The sensitivity for humidity sensing were determined for both films of TiO2 and Al2O3-TiO2 and corresponding values are found to be 74.2% and 84.02%, this result reveal that Al2O3-TiO2 films shows higher sensing percent than the TiO2 due to the nano porous surface nature. The Al2O3-TiO2 film shows fast response time and long recovery time than the TiO2 film, this may be due to the meso-porous morphology of these films.

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

    PubMed

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

    2010-03-01

    Ag-glass composite powders with various glass contents and excellent conducting properties were prepared by spray pyrolysis. Irrespective of the glass content, all the prepared powders were found to comprise spherical particles with nonaggregation characteristics. The crystal structure of the powder particles resembled that of pure Ag particles, irrespective of the glass content. Conducting layers formed from pure Ag did not melt even when sintered at 400 degrees C. On the other hand, conducting layers formed from composite powders containing 3 and 5 wt% glass melted when sintered at 400 degrees C. The optimum glass content of the composite powders was 3 wt% at sintering temperatures of 400 and 450 degrees C. However, the optimum glass content decreased to 1 wt% when the sintering temperature was increased to 550 degrees C. The lowest specific resistances of the conducting layers formed from the composite powders were 5.3 and 2.3 microohms-cm at sintering temperatures of 400 and 550 degrees C, respectively. PMID:20036371

  6. Synthesis of nanocrystalline Cu{sub 2}ZnSnS{sub 4} thin films grown by the spray-pyrolysis technique

    SciTech Connect

    Chandel, Tarun Singh, Joginder; Rajaram, P.

    2015-08-28

    Spray pyrolysis was used to deposit Cu{sub 2}ZnSnS{sub 4} (CZTS) thin films on soda lime glass substrates at 300 °C. Aqueous solutions of copper chloride, zinc chloride, stannous chloride and thiourea were mixed together to form the spray liquid. The sprayed films were annealed under vacuum at 350 °C, 400 °C and 450 °C. Structural and optical characterization was performed on the CZTS films using X-ray diffraction (XRD) and UV-VIS spectrophotometry. XRD results indicate that the films are single phase nanocrystalline CZTS. Optical studies show that the optical gap values are 1.44 eV for the as-grown film and 1.46 eV, 1.48 eV and 1.49 eV for the films annealed at 350 °C, 400 °C and 450 °C, respectively.

  7. Effects of drying control chemical additive on properties of Li 4Ti 5O 12 negative powders prepared by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Ju, Seo Hee; Kang, Yun Chan

    High-density Li 4Ti 5O 12 powders comprising spherical particles are prepared by spray pyrolysis from a solution containing dimethylacetamide (drying control chemical additive) and citric acid and ethylene glycol (organic additives). The prepared powders have high discharge capacities and good cycle properties. The optimum concentration of dimethylacetamide is 0.5 M. The addition of dimethylacetamide to the polymeric spray solutions containing citric acid and ethylene glycol helps in the effective control of the morphology of the Li 4Ti 5O 12 powders. At a constant current density of 0.17 mA g -1, the initial discharge capacities of the powders obtained from the spray solution with and without the organic additives are 171 and 167 mAh g -1, respectively.

  8. High-Temperature Jet Spray Reactor for the Preparation of Rare Earth Oxides by Pyrolysis: Computer Simulation

    NASA Astrophysics Data System (ADS)

    Zhao, Qiu-yue; Lv, Chao; Zhang, Zi-mu; Dou, Zhi-he; Zhang, Ting-an; Liu, Yan; Lv, Guo-zhi

    2014-09-01

    A new type of high-temperature jet spray pyrolysis (SP) reactor is investigated in this article as part of studies on the preparation of rare earth oxides at Northeastern University (NEU), Shenyang, China. The jet spray reactor examined here is a horizontal, tubular reactor conveying the hot products of the combustion of methane and oxygen with a converging-diverging jet section in an arrangement that provides for inspiration of LaCl3 solution to pyrolyze to La2O3 with the hot gas. The present article is concerned with a computer simulation using a computational fluid dynamic model to develop the velocity, temperature, and pressure profiles in the jet reactor since direct measurement is difficult. The article includes brief comments on a room-temperature model designed to examine the flow characteristics of the jet SP reactor. It was found that the velocity decreased at first, and then it increased near the jet throat. The highest velocity occurred at the throat of jet SP reactor where the LaCl3 enters the unit. Along the reactor axis, the temperature decreases with distance from the gas inlet. The lowest temperature zone was near the wall before the throat of the reactor due to wall heat losses. The temperature was estimated to be close to 1700 K at the throat of the reactor, and it was about 1300 K toward the exit of the reactor. It was shown that a reaction would take place mainly in the throat and in the vicinity of first contact between gas and induced spray. A negative pressure was produced as gas passes through the converging-diverging throat of the jet SP reactor that causes the LaCl3 solution to enter the throat of the reactor. While the investigations of this type of reactor are at an early stage, the results look promising. NEU continues to investigate this approach for the preparation of La2O3 based on high-temperature testwork and physical modeling techniques.

  9. High-Temperature Jet Spray Reactor for the Preparation of Rare Earth Oxides by Pyrolysis: Computer Simulation

    NASA Astrophysics Data System (ADS)

    Zhao, Qiu-yue; Lv, Chao; Zhang, Zi-mu; Dou, Zhi-he; Zhang, Ting-an; Liu, Yan; Lv, Guo-zhi

    2014-08-01

    A new type of high-temperature jet spray pyrolysis (SP) reactor is investigated in this article as part of studies on the preparation of rare earth oxides at Northeastern University (NEU), Shenyang, China. The jet spray reactor examined here is a horizontal, tubular reactor conveying the hot products of the combustion of methane and oxygen with a converging-diverging jet section in an arrangement that provides for inspiration of LaCl3 solution to pyrolyze to La2O3 with the hot gas. The present article is concerned with a computer simulation using a computational fluid dynamic model to develop the velocity, temperature, and pressure profiles in the jet reactor since direct measurement is difficult. The article includes brief comments on a room-temperature model designed to examine the flow characteristics of the jet SP reactor. It was found that the velocity decreased at first, and then it increased near the jet throat. The highest velocity occurred at the throat of jet SP reactor where the LaCl3 enters the unit. Along the reactor axis, the temperature decreases with distance from the gas inlet. The lowest temperature zone was near the wall before the throat of the reactor due to wall heat losses. The temperature was estimated to be close to 1700 K at the throat of the reactor, and it was about 1300 K toward the exit of the reactor. It was shown that a reaction would take place mainly in the throat and in the vicinity of first contact between gas and induced spray. A negative pressure was produced as gas passes through the converging-diverging throat of the jet SP reactor that causes the LaCl3 solution to enter the throat of the reactor. While the investigations of this type of reactor are at an early stage, the results look promising. NEU continues to investigate this approach for the preparation of La2O3 based on high-temperature testwork and physical modeling techniques.

  10. Polymer and surfactant-templated synthesis of hollow and porous ZnS nano- and microspheres in a spray pyrolysis reactor.

    PubMed

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

    2015-01-13

    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.

  11. Effects of synthesis conditions on Curie temperature of La0.75Sr0.25MnO3 fine particles formed by ultrasonic spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Kinoshita, Takuya; Furuyabu, Takamitsu; Adachi, Motoaki

    2014-10-01

    Manganese perovskite La0.75Sr0.25MnO3 (LSM) fine particles were synthesized by an ultrasonic spray pyrolysis method at various synthesis temperatures (Ts), reaction times (tr), and source solution concentrations (Ctotal) to clarify the effects of these synthesis conditions on their Curie temperature Tc and maximum particle temperature attained by magnetic heating at Thmax. At constant Ctotal, the Tc of synthesized LSM particles was increased from 288.6 to 363.5 K (15.6 to 90.5 °C) by increasing Ts from 1073 to 1627 K (800 to 1400 °C), and was increased from 281.8 to 339 K (8.89 to 66 °C) by increasing tr from 2.4 to 19 s. When the AC magnetic field was applied, the particles generated heat, and the particle temperature Th increased with time for t < about 2 min, and then attained constant Thmax near Tc. Thmax increased with increasing Tc. The LSM particles produced at Ts = 1213 K, Ctotal = 0.5 mol L-1, and tr = 9.4 s had Thmax = 316.6 K (43.6 °C), which is within the temperature range of 316-318 K (43-45 °C) for hyperthermia therapy for cancer.

  12. Pyrolysis and catalytic pyrolysis as a recycling method of waste CDs originating from polycarbonate and HIPS.

    PubMed

    Antonakou, E V; Kalogiannis, K G; Stephanidis, S D; Triantafyllidis, K S; Lappas, A A; Achilias, D S

    2014-12-01

    Pyrolysis appears to be a promising recycling process since it could convert the disposed polymers to hydrocarbon based fuels or various useful chemicals. In the current study, two model polymers found in WEEEs, namely polycarbonate (PC) and high impact polystyrene (HIPS) and their counterparts found in waste commercial Compact Discs (CDs) were pyrolysed in a bench scale reactor. Both, thermal pyrolysis and pyrolysis in the presence of two catalytic materials (basic MgO and acidic ZSM-5 zeolite) was performed for all four types of polymers. Results have shown significant recovery of the monomers and valuable chemicals (phenols in the case of PC and aromatic hydrocarbons in the case of HIPS), while catalysts seem to decrease the selectivity towards the monomers and enhance the selectivity towards other desirable compounds.

  13. Spray drift reduction test method correlation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ASTM Standard E609 Terminology Relating to Pesticides defines drift as “The physical movement of an agrochemical through the air at the time of application or soon thereafter to any non or off target site.” Since there are many commercial tank mix adjuvants designed to reduce spray drift, ASTM esta...

  14. Preparation of iron aluminate (FeAl2O4) nanoparticles from FeAl2O4 hollow particles fabricated by using a spray pyrolysis process

    NASA Astrophysics Data System (ADS)

    Yun, Jaecheol; Kim, Yangdo; Park, Dahee; Yun, Jung-Yeul

    2015-05-01

    Iron aluminate (FeAl2O4) hollow particles with a spinel structure were synthesized by using a spray pyrolysis process. FeAl2O4 hollow particles were formed at a reaction temperature of 900 °C at a flow rate of 40 L/min as a result of the rapid solvent evaporation and decomposition gases from the droplets in the spray solution prepared from metal salts and organic reagents. FeAl2O4 hollow particles were fabricated at a reaction temperature of 900 °C with a flow rate of 40 L/min. The FeAl2O4 hollow particles were heat treated for 3 hours at 600 °C in a 5% H2/Ar atmosphere to form the crystal particles. Subsequently, FeAl2O4 nanoparticles were fabricated from the FeAl2O4 hollow particles by using the wet milling process. After milling for 60 minutes, transmission electron microscopy revealed the FeAl2O4 particles to have a mean size of approximately 50 nm. The FeAl2O4 nanoparticles were fabricated successfully by using a two-step process, spray pyrolysis and wet milling.

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

    SciTech Connect

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

    2003-02-20

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

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

    SciTech Connect

    Swapna, R. E-mail: santhoshmc@nitt.edu; Amiruddin, R. E-mail: santhoshmc@nitt.edu; Santhosh Kumar, M. C. E-mail: santhoshmc@nitt.edu

    2014-01-28

    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} Ω 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.

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

    SciTech Connect

    Jiang, Changyun; Koh, Wei Lin; Leung, Man Yin; Hong, Wei; Li, Yuning; Zhang, Jie

    2013-02-15

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

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

    NASA Astrophysics Data System (ADS)

    Doan, The Nam Long; Taniguchi, Izumi

    LiMnPO 4/C nanocomposites could be prepared by a combination of spray pyrolysis and wet ball-milling followed by heat treatment in the range of spray pyrolysis temperature from 200 to 500 °C. The ordered LiMnPO 4 olivine structure without any impurity phase could be identified by X-ray diffraction analysis for all samples. It could be also confirmed from scanning electron microscopy and transmission electron microscopy observations that the final samples were the LiMnPO 4/C nanocomposites with approximately 100 nm in primary particles size. The LiMnPO 4/C nanocomposite samples were used as cathode active materials for lithium batteries, and the electrochemical tests were carried out for the cell Li|1 M LiPF 6 in EC:DMC = 1:1|LiMnPO 4/C at various charge/discharge rates in three charge modes. As a result, the final sample which was synthesized at 300 °C by spray pyrolysis showed the best electrochemical performance due to the largest specific surface area, the smallest primary particle size and a well distribution of carbon. At galvanostatic charge/discharge rates of 0.05 C, the cell delivered first discharge capacities of 123 and 165 mAh g -1 in correspondence to charge cutoff voltages of 4.4 and 5.0 V, respectively. Furthermore, in a constant current-constant voltage charge mode at 4.4 V, the cells also exhibited initial discharge capacities of 147 mAh g -1 at 0.05 C, 145 mAh g -1 at 0.1 C, 123 mAh g -1 at 1 C and 65 mAh g -1 at 10 C. Moreover, the cells showed fair good cycleability over 100 cycles.

  19. Method and apparatus for spraying molten materials

    DOEpatents

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

    1996-01-01

    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.

  20. Method and apparatus for spraying molten materials

    DOEpatents

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

    1996-06-25

    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.

  1. Method of producing thermally sprayed metallic coating

    DOEpatents

    Byrnes, Larry Edward; Kramer, Martin Stephen; Neiser, Richard A.

    2003-08-26

    The cylinder walls of light metal engine blocks are thermally spray coated with a ferrous-based coating using an HVOF device. A ferrous-based wire is fed to the HVOF device to locate a tip end of the wire in a high temperature zone of the device. Jet flows of oxygen and gaseous fuel are fed to the high temperature zone and are combusted to generate heat to melt the tip end. The oxygen is oversupplied in relation to the gaseous fuel. The excess oxygen reacts with and burns a fraction of the ferrous-based feed wire in an exothermic reaction to generate substantial supplemental heat to the HVOF device. The molten/combusted metal is sprayed by the device onto the walls of the cylinder by the jet flow of gases.

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

    SciTech Connect

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

    2014-04-24

    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.

  3. Method for preventing plugging in the pyrolysis of agglomerative coals

    DOEpatents

    Green, Norman W.

    1979-01-23

    To prevent plugging in a pyrolysis operation where an agglomerative coal in a nondeleteriously reactive carrier gas is injected as a turbulent jet from an opening into an elongate pyrolysis reactor, the coal is comminuted to a size where the particles under operating conditions will detackify prior to contact with internal reactor surfaces while a secondary flow of fluid is introduced along the peripheral inner surface of the reactor to prevent backflow of the coal particles. The pyrolysis operation is depicted by two equations which enable preselection of conditions which insure prevention of reactor plugging.

  4. Synthesis of Zn1- x Co x Al2O4 Spinel Nanoparticles by Liquid-Feed Flame Spray Pyrolysis: Ceramic Pigments Application

    NASA Astrophysics Data System (ADS)

    Betancur Granados, Natalia; Yi, Eongyu; Laine, Richard M.; Restrepo Baena, Oscar Jaime

    2016-01-01

    Zn1- x Co x Al2O4 ( x = 0.0, 0.2, 0.4, 0.6, 0.8, and 1.0) spinel nanoparticles were synthesized by a liquid-feed flame spray pyrolysis (LF-FSP) method by combusting metallorganic precursor solutions to produce nanopowders with precise composition control. The precursor solutions were aerosolized into a methane/oxygen flame where it was combusted in an oxygen-rich environment to result in nanopowders at a single step. The nanopowders were analyzed by x-ray diffraction, Fourier transform infrared spectroscopy, colorimetry, field emission scanning electron microscopy, transmission electron microscopy, and BET (Brunauer-Emmett-Teller) N2 adsorption. Results show formation of spherical nanopowders with specific surface areas of 42 m2/g to 50 m2/g, which correspond to average particle sizes of 26 nm to 31 nm. Single-phase materials were obtained with a high control of composition, which indicates that LF-FSP is an excellent method to produce mixed-metal oxides for applications in which powder homogeneity is crucial. The products were evaluated for ceramic pigment application, where the ratio of Zn to Co was gradually changed to observe the color change in the structure with the increase of cobalt concentration. The resulting pigments were calcined at 1200°C, which aimed to identify the color stability after a high-temperature process, whereby the colors were measured using the color space CIE L*a*b* under standardized light, D65. Finally, the powders were tested for ceramic decoration using transparent glazes and ceramic bodies. The application was carried out at 1250°C to evaluate the color performance after a decoration process.

  5. One-Pot Synthesis of CoSex -rGO Composite Powders by Spray Pyrolysis and Their Application as Anode Material for Sodium-Ion Batteries.

    PubMed

    Park, Gi Dae; Kang, Yun Chan

    2016-03-14

    A simple one-pot synthesis of metal selenide/reduced graphene oxide (rGO) composite powders for application as anode materials in sodium-ion batteries was developed. The detailed mechanism of formation of the CoSe(x)-rGO composite powders that were selected as the first target material in the spray pyrolysis process was studied. The crumple-structured CoSe(x)-rGO composite powders prepared by spray pyrolysis at 800 °C had a crystal structure consisting mainly of Co0.85 Se with a minor phase of CoSe2. The bare CoSe(x) powders prepared for comparison had a spherical shape and hollow structure. The discharge capacities of the CoSe(x)-rGO composite and bare CoSe(x) powders in the 50th cycle at a constant current density of 0.3 A g(-1) were 420 and 215 mA h g(-1), respectively, and their capacity retentions measured from the second cycle were 80 and 46%, respectively. The high structural stability of the CoSe(x)-rGO composite powders for repeated sodium-ion charge and discharge processes resulted in superior sodium-ion storage properties compared to those of the bare CoSe(x) powders.

  6. Electrochemical properties of hollow-structured MnS-carbon nanocomposite powders prepared by a one-pot spray pyrolysis process.

    PubMed

    Lee, Su Min; Lee, Jung-Kul; Kang, Yun Chan

    2014-02-01

    Spherical, hollow MnS-C composite powders were prepared from a solution of manganese salt, thiourea, and sucrose by one-pot spray pyrolysis. The MnS-C composite powders were generated by direct sulfidation of MnO with hydrogen sulfide gas generated in situ by decomposition of thiourea during spray pyrolysis. Sucrose, which is used as a carbon source material, plays a key role in the formation of the MnS-C composite powders by improving the reducing atmosphere around the powders. Dot-mapping images of the composite powders demonstrated uniform distribution of the manganese, sulfur, and carbon components within the MnS-C composite powder. Fine crystals of MnS were uniformly mixed with carbon derived from polymerization and carbonization of sucrose. The carbon content of the MnS-C composite powders was 26 wt%. The discharge capacities of the MnS-C composite powders in the 2nd and 200th cycles were 863 and 967 mA h g(-1), respectively, at a current density of 1000 mA g(-1). The spherical and hollow morphology of the MnS-C composite powders was completely retained, even after 200 cycles. The enhanced cycling and rate performance of the MnS-C composite powders is ascribed to the structural stability of the composite powders.

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

    NASA Astrophysics Data System (ADS)

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

    2012-09-01

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

  8. Physical and electrochemical properties of LiFePO 4 nanoparticles synthesized by a combination of spray pyrolysis with wet ball-milling

    NASA Astrophysics Data System (ADS)

    Konarova, Muxina; Taniguchi, Izumi

    A novel preparation technique was developed to synthesize LiFePO 4 nanoparticles through a combination of spray pyrolysis (SP) with wet ball-milling (WBM). Using this technique, the preparation of LiFePO 4 nanoparticles was investigated for a wide range of process parameters such as ball-milling time and sintering temperature. The effect of process parameters on the physical and electrochemical properties of LiFePO 4 was then discussed through analysis using by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), the Brunauer-Emmet-Teller (BET) method, Raman spectroscopy and using an electrochemical cell of Li|1 M LiClO 4 in EC:DEC = 1:1|LiFePO 4. LiFePO 4 nanoparticles with a geometric mean diameter of 58 nm were prepared at a rotating speed of 800 rpm and a ball-milling time of 12 h in an Ar atmosphere followed by heat treatment at 500 °C for 4 h in a N 2 + 3% H 2 atmosphere. The sample delivered first discharge capacities of 164 and 100 mAh g -1 at charge-discharge rates of 0.1 and 10 C in the test cells, respectively. The electrochemical properties of LiFePO 4 nanoparticles were strongly affected by the formation of Fe 2P, Fe 3P and α-Fe 2O 3 at higher charge-discharge rates.

  9. Flame spray pyrolysis for finding multicomponent nanomaterials with superior electrochemical properties in the CoO(x)-FeO(x) system for use in lithium-ion batteries.

    PubMed

    Kim, Jung Hyun; Lee, Jong-Heun; Kang, Yun Chan

    2014-10-01

    High-temperature flame spray pyrolysis is employed for finding highly efficient nanomaterials for use in lithium-ion batteries. CoO(x)-FeO(x) nanopowders with various compositions are prepared by one-pot high-temperature flame spray pyrolysis. The Co and Fe components are uniformly distributed over the CoO(x)-FeO(x) composite powders, irrespective of the Co/Fe mole ratio. The Co-rich CoO(x)-FeO(x) composite powders with Co/Fe mole ratios of 3:1 and 2:1 have mixed crystal structures with CoFe2O4 and Co3O4 phases. However, Co-substituted magnetite composite powders prepared from spray solutions with Co and Fe components in mole ratios of 1:3, 1:2, and 1:1 have a single phase. Multicomponent CoO(x)-FeO(x) powders with a Co/Fe mole ratio of 2:1 and a mixed crystal structure with Co3O4 and CoFe2O4 phases show high initial capacities and good cycling performance. The stable reversible discharge capacities of the composite powders with a Co/Fe mole ratio of 2:1 decrease from 1165 to 820 mA h g(-1) as the current density is increased from 500 to 5000 mA g(-1); however, the discharge capacity again increases to 1310 mA h g(-1) as the current density is restored to 500 mA g(-1). PMID:25065898

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

    NASA Astrophysics Data System (ADS)

    Azurdia, Jose Antonio

    The liquid-feed flame spray pyrolysis (LF-FSP) process aerosolizes metal-carboxylate precursors dissolved in alcohol with oxygen and combusts them at >1500°C. The products are quenched rapidly (˜10s msec) to < 400°C. By selecting the appropriate precursor mixtures, the compositions of the resulting oxide nanopowders can be tailored easily, which lends itself to combinatorial studies of systems facilitating material property optimization. The resulting nanopowders typically consist of single crystal particles with average particle sizes (APS) < 35 nm, specific surface areas (SSA) of 20-60 m2/g and spherical morphology. LF-FSP provides access to novel single phase nanopowders, known phases at compositions outside their published phase diagrams, intimate mixing at nanometer length scales in multi metallic oxide nanopowders, and control of stoichiometry to ppm levels. The materials produced may exhibit unusual properties including structural, catalytic, and photonic ones and lower sintering temperatures. Prior studies used LF-FSP to produce MgAl2O4 spinel for applications in transparent armor and IR radomes. In these studies, a stable spinel structure with a (MgO)0.1(Al2O3)0.9 composition well outside the known phase field was observed. The work reported here extends this observation to two other spinel systems: Al2O3-NiO, Al2O3-CoOx; followed by three series of transition metal binary oxides, NiO-CoO, NiO-MoO3, NiO-CuO. The impetus to study spinels derives both from the fact that a number of them are known transparent ceramics, but also others offer high SSAs coupled with unusual phases that suggest potentially novel catalytic materials. Because LF-FSP provides access to any composition, comprehensive studies of the entire tie-lines were conducted rather than just compositions of value for catalytic applications. Initial efforts established baseline properties for the nano aluminate spinels, then three binary transition metal oxide sets (Ni-Co, Ni-Mo and Ni

  11. Method of producing pyrolysis gases from carbon-containing materials

    DOEpatents

    Mudge, Lyle K.; Brown, Michael D.; Wilcox, Wayne A.; Baker, Eddie G.

    1989-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

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

  13. High electron mobility thin-film transistors based on Ga{sub 2}O{sub 3} grown by atmospheric ultrasonic spray pyrolysis at low temperatures

    SciTech Connect

    Thomas, Stuart R. E-mail: thomas.anthopoulos@imperial.ac.uk; Lin, Yen-Hung; Faber, Hendrik; Anthopoulos, Thomas D. E-mail: thomas.anthopoulos@imperial.ac.uk; Adamopoulos, George; Sygellou, Labrini; Stratakis, Emmanuel; Pliatsikas, Nikos; Patsalas, Panos A.

    2014-09-01

    We report on thin-film transistors based on Ga{sub 2}O{sub 3} 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 Ga{sub 2}O{sub 3} 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 Ga{sub 2}O{sub 3} films show n-type conductivity with the maximum electron mobility of ∼2 cm{sup 2}/V s.

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

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

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

  15. Computational Analysis of the Optical and Charge Transport Properties of Ultrasonic Spray Pyrolysis-Grown Zinc Oxide/Graphene Hybrid Structures.

    PubMed

    Ali, Amgad Ahmed; Hashim, Abdul Manaf

    2016-12-01

    We demonstrate a systematic computational analysis of the measured optical and charge transport properties of the spray pyrolysis-grown ZnO nanostructures, i.e. nanosphere clusters (NSCs), nanorods (NRs) and nanowires (NWs) for the first time. The calculated absorbance spectra based on the time-dependent density functional theory (TD-DFT) shows very close similarity with the measured behaviours under UV light. The atomic models and energy level diagrams for the grown nanostructures were developed and discussed to explain the structural defects and band gap. The induced stresses in the lattices of ZnO NSCs that formed during the pyrolysis process seem to cause the narrowing of the gap between the energy levels. ZnO NWs and NRs show homogeneous distribution of the LUMO and HOMO orbitals all over the entire heterostructure. Such distribution contributes to the reduction of the band gap down to 2.8 eV, which has been confirmed to be in a good agreement with the experimental results. ZnO NWs and NRs exhibited better emission behaviours under the UV excitation as compared to ZnO NSCs and thin film as their visible range emissions are strongly quenched. Based on the electrochemical impedance measurement, the electrical models and electrostatic potential maps were developed to calculate the electron lifetime and to explain the mobility or diffusion behaviours in the grown nanostructure, respectively. PMID:27173675

  16. Computational Analysis of the Optical and Charge Transport Properties of Ultrasonic Spray Pyrolysis-Grown Zinc Oxide/Graphene Hybrid Structures

    NASA Astrophysics Data System (ADS)

    Ali, Amgad Ahmed; Hashim, Abdul Manaf

    2016-05-01

    We demonstrate a systematic computational analysis of the measured optical and charge transport properties of the spray pyrolysis-grown ZnO nanostructures, i.e. nanosphere clusters (NSCs), nanorods (NRs) and nanowires (NWs) for the first time. The calculated absorbance spectra based on the time-dependent density functional theory (TD-DFT) shows very close similarity with the measured behaviours under UV light. The atomic models and energy level diagrams for the grown nanostructures were developed and discussed to explain the structural defects and band gap. The induced stresses in the lattices of ZnO NSCs that formed during the pyrolysis process seem to cause the narrowing of the gap between the energy levels. ZnO NWs and NRs show homogeneous distribution of the LUMO and HOMO orbitals all over the entire heterostructure. Such distribution contributes to the reduction of the band gap down to 2.8 eV, which has been confirmed to be in a good agreement with the experimental results. ZnO NWs and NRs exhibited better emission behaviours under the UV excitation as compared to ZnO NSCs and thin film as their visible range emissions are strongly quenched. Based on the electrochemical impedance measurement, the electrical models and electrostatic potential maps were developed to calculate the electron lifetime and to explain the mobility or diffusion behaviours in the grown nanostructure, respectively.

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

    PubMed

    Hong, Young Jun; Kang, Yun Chan

    2015-01-14

    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).

  18. Electrochemical properties of bare nickel sulfide and nickel sulfide-carbon composites prepared by one-pot spray pyrolysis as anode materials for lithium secondary batteries

    NASA Astrophysics Data System (ADS)

    Son, Mun Yeong; Choi, Jeong Hoo; Kang, Yun Chan

    2014-04-01

    Spherical bare nickel sulfide and nickel sulfide-carbon composite powders are prepared by a one-step spray pyrolysis. Submicron bare nickel sulfide particles with a dense structure have mixed crystal phases of NiS, Ni7S6, and NixS6. The nickel sulfide-carbon composite powders prepared from a spray solution containing 0.1 M sucrose have a main crystal structure of Ni7S6 phase with small impurity peaks of NixS6 phase. A nickel oxide-carbon composite powder is first formed as an intermediate product in the front part of the reactor at 800 °C. Fast decomposition of thiourea at this high temperature results in the evolution of hydrogen sulfide gas, which then forms the nickel sulfide-carbon composite powders by direct sulfidation of nickel oxide under the reducing atmosphere. Nickel sulfide nanocrystals with a size of a few nanometers are uniformly distributed inside the spherical carbon matrix. The nickel sulfide-carbon composite powders prepared with 0.1 M sucrose have an excellent discharge capacity of 472 mA h g-1 at a high current density of 1000 mA g-1, even after 500 cycles, with the corresponding capacity retention measured after the first cycle being 86%.

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

    PubMed Central

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

    2010-01-01

    Piroxicam, an anti-inflammatory drug, exhibits poor water solubility and flow properties, poor dissolution and poor wetting. Consequently, the aim of this study was to improve the dissolution of piroxicam. Microparticles containing piroxicam were produced by spray drying, using isopropyl alcohol and water in the ratio of 40:60 v/v as solvent system, and spray chilling technology by melting the drug and chilling it with a pneumatic nozzle to enhance dissolution rate. The prepared formulations were evaluated for in vitro dissolution and solubility. The prepared drug particles were characterized by scanning electron microscopy (SEM), differential scanning calorimeter, X-ray diffraction and Fourier transform infrared spectroscopy. Dissolution profile of the spray dried microparticles was compared with spray-chilled microparticles, pure and recrystallized samples. Spray dried microparticles and spray chilled microparticles exhibited decreased crystallinity and improved micromeritic properties. The dissolution of the spray dried microparticle and spray chilled particles were improved compared with recrystallized and pure sample of piroxicam. Consequently, it was believed that spray drying of piroxicam is a useful tool to improve dissolution but not in case of spray chilling. This may be due to the degradation of drug or variations in the resonance structure or could be due to minor distortion of bond angles. Hence, this spray drying technique can be used for formulation of tablets of piroxicam by direct compression with directly compressible tablet excipients. PMID:21589797

  20. Manual fire suppression methods on typical machinery space spray fires

    NASA Astrophysics Data System (ADS)

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

    1990-07-01

    A series of tests was conducted to evaluate the effectiveness of Aqueous Film Forming Foam (AFFF), potassium bicarbonate powder (PKP) and Halon 1211, alone and in various combinations, in extinguishing spray fires. The sprays were generated by JP-5 jet fuel issuing from an open sounding tube, and open petcock, a leaking flange or a slit pipe, and contacting an ignition source. The results indicate that typical fuel spray fires, such as those simulated in this series, are very severe. Flame heights ranged from 6.1 m (20 ft) for the split pipe to 15.2 m (50 ft) for the sounding tube scenario. These large flame geometries were accompanied by heat release rates of 6 MW to greater than 50 MW, and hazardous thermal radiation levels in the near field environment, up to 9.1 m (30 ft) away. Successful suppression of these fires requires both a significant reduction in flame radiation and delivery of a suppression agent to shielded areas. Of the nine suppression methods tested, the 95 gpm AFFF hand line and the hand line in conjunction with PKP were particularly effective in reducing the radiant flux.

  1. Method and apparatus for atomization and spraying of molten metals

    DOEpatents

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

    1988-07-19

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

  2. Method and apparatus for atomization and spraying of molten metals

    DOEpatents

    Hobson, David O.; Alexeff, Igor; Sikka, Vinod K.

    1990-01-01

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

  3. CuS p- type thin film characterization deposited on Ti, ITO and glass substrates using spray pyrolysis deposition (SPD) for light emitting diode (LED) application

    NASA Astrophysics Data System (ADS)

    Sabah, Fayroz A.; Ahmed, Naser M.; Hassan, Z.; Rasheed, Hiba S.; Azzez, Shrook A.; Al-Hazim, Nabeel Z.

    2016-07-01

    The copper sulphide (CuS) thin films were grown with good adhesion by spray pyrolysis deposition (SPD) on Ti, ITO and glass substrates at 200 °C. The distance between nozzle and substrate is 30 cm. The composition was prepared by mixing copper chloride CuCl2.2H2O as a source of Cu2+ and sodium thiosulfate Na2S2O3.5H2O as a source of and S2-. Two concentrations (0.2 and 0.4 M) were used for each CuCl2 and Na2S2O3 to be prepared and then sprayed (20 ml). The process was started by spraying the solution for 3 seconds and after 10 seconds the cycle was repeated until the solution was sprayed completely on the hot substrates. The structural characteristics were studied using X-ray diffraction; they showed covellite CuS hexagonal crystal structure for 0.2 M concentration, and covellite CuS hexagonal crystal structure with two small peaks of chalcocite Cu2S hexagonal crystal structure for 0.4 M concentration. Also the surface and electrical characteristics were investigated using Field Emission Scanning Electron Microscopy (FESEM) and current source device, respectively. The surface study for the CuS thin films showed nanorods to be established for 0.2 M concentration and mix of nanorods and nanoplates for 0.4 M concentration. The electrical study showed ohmic behavior and low resistivity for these films. Hall Effect was measured for these thin films, it showed that all samples of CuS are p- type thin films and ensured that the resistivity for thin films of 0.2 M concentration was lower than that of 0.4 M concentration; and for the two concentrations CuS thin film deposited on ITO had the lowest resistivity. This leads to the result that the conductivity was high for CuS thin film deposited on ITO substrate, and the conductivity of the three thin films of 0.2 M concentration was higher than that of 0.4 M concentration.

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

    NASA Astrophysics Data System (ADS)

    Hong, Young Jun; Kang, Yun Chan

    2014-12-01

    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

  5. Colloidal spray method for low cost thin coating deposition

    DOEpatents

    Pham, Ai-Quoc; Glass, Robert S.; Lee, Tae H.

    2002-01-01

    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.

  6. Colloidal spray method for low cost thin coating deposition

    DOEpatents

    Pham, Ai-Quoc; Glass, Robert S.; Lee, Tae H.

    2005-01-25

    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.

  7. 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)

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

    2014-12-01

    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.

  8. Peculiarities in electrical and optical properties of Cu2Zn1- x Mn x SnS4 films obtained by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Orletskii, I. G.; Mar'yanchuk, P. D.; Solovan, M. N.; Maistruk, E. V.; Kozyarskii, D. P.

    2016-03-01

    Thin films of Cu2Zn1- x Mn x SnS4 (0 ≤ x ≤ 1) solid solutions have been obtained for the first time by the spray pyrolysis of aqueous salt solutions (copper, zinc, manganese, and tin chlorides and thiourea) at a temperature of T S = 563 K. The films possess specific electric conductivities within σ ≈ 35-422 Ω-1 cm-1 and optical bandgap width E g op that increases with the manganese content from 1.54 eV ( x = 0) to 2.25 eV ( x = 1). Electrical and optical properties of the obtained films have been studied and analyzed based on a model of polycrystalline materials with grain boundaries. The energy barriers Eb between grains have been determined. The dependence of the bandgap of Cu2Zn1- x Mn x SnS4 (0 ≤ x ≤ 1) solid solutions on the composition has been established using the results of measurements of the optical transmission and absorption coefficients.

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

    SciTech Connect

    Jung, Kyeong Youl . E-mail: kyjung@krict.re.kr; Lee, Dong Youl; Kang, Yun Chan

    2005-12-08

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

  10. Effects of Different Salts on Salt-Assisted Ultrasonic Spray Pyrolysis (SA-USP) Calcination for the Synthesis of Strontium Ferrite.

    PubMed

    Hwang, Tea-Yeon; An, Guk-Hwan; Cho, Jeong-Ho; Kim, Jongryoul; Choa, Yong-Ho

    2015-10-01

    Strontium ferrite (hexaferrite), SrFe12O19, was successfully fabricated in sizes ranging from hundreds of nanometers to several micrometers by salt-assisted ultrasonic spray pyrolysis-calcination using different salt media. All samples were single phases of SrFe12O19 without the intermediate phase, α-Fe2O3, and their morphology was hexagonal. As calcination temperature increased, the size of as-calcined samples and saturation magnetization, Ms, increased while coercivity decreased. The particle size of the obtained nanoparticles varied depending on the salt media and calcination temperatures. The best magnetic properties obtained in this experiment were a coercivity of 6973 Oe with a saturation magnetization of 68.3 emu/g. To the best of our knowledge, these coercivity values are the highest ever obtained. We propose a detailed mechanism explaining the growth of these particles and conclude that the resulting single-domain particle size is about 70 nm, taking into account of factors affecting coercivity in ferrite nano- to micro-sized particles. PMID:26726463

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

    PubMed

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

    2015-03-01

    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.

  12. Effect of F doping on physical properties of (211) oriented SnO2 thin films prepared by jet nebulizer spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Thirumoorthi, M.; Prakash, J. Thomas Joseph

    2016-01-01

    Transparent conducting fluorine doped tin oxide (FTO) thin films have been prepared jet nebulizer spray pyrolysis technique at 500 °C for different doping concentrations. The X-ray diffraction spectra confirm the polycrystalline nature of SnO2: F with tetragonal structure. All the films show a preferred growth orientation along (211) diffraction plane. Scanning electron microscope images show that the films have a uniform surface morphology with well defined pyramid like grains. The AFM results of the films indicate that the surface roughness is increased with F doping. The optical transmittance of FTO films is improved from 75 to 92% in the visible region of the solar spectrum and the optical absorption of the films is very low. The blue shift of optical band of the films is explained by Burstain-Mass effect. The observed blue shift of the UV emission band in the photoluminescence spectra confirms the incorporation of F into tin oxide crystal lattice. The presence of functional groups and chemical bonding were confirmed by FTIR. Hall Effect measurements show that the prepared films having n-type conductivity with low resistivity (2.3 × 10-4 Ω-cm) and high carrier concentrations (6.9 × 1020 cm-3).

  13. Effect of Sn doping on the structural, optical and electrical properties of TiO2 films prepared by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Arunachalam, A.; Dhanapandian, S.; Manoharan, C.

    2016-02-01

    In this work, highly oriented pure and Tin-doped Titanium dioxide (Sn-doped TiO2) with porous nature photoelectrodes were deposited on ITO glass plates using spray pyrolysis technique. The XRD pattern revealed the formation of anatase TiO2 with the maximum intensity of (101) plane while doping 6 at% of Sn. The morphological studies depicted the porous nature with the uniform arrangement of small-sized grains. The presence of tin confirmed with the EDX spectra. The size of particles of 13 nm was observed from High Resolution Transmission Electron Microscopy (HR-TEM) analysis. The average transmittance was about 85% for the doped photoelectrode and was observed for the photoelectrode deposited with 6 at% of tin, with decreased energy band gap. The PL study showed the emission peak at 391 nm. The maximum carrier concentration and Hall mobility was observed for the photoelectrode deposited with 6 at% of tin. With these studies, the DSSCs were prepared separately with the dye extracted from Hibiscus Rosasinesis and Hibiscus Surttasinesis and their efficiency was maximum for the DSSC prepared with 6 at% of tin.

  14. Spray automated balancing of rotors: Methods and materials

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

    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.

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

    PubMed

    Sandercock, P Mark L

    2012-05-01

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

  16. Numerical modeling of spray combustion with an advanced VOF method

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

    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.

  17. 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)

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

    2012-06-01

    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.

  18. Spray pyrolysis deposition of Cu-ZnO and Zn-SnO{sub 2} solar cells

    SciTech Connect

    Khelfane, A.; Tarzalt, H.; Sebboua, B.; Zerrouki, H.; Kesri, N.

    2015-12-31

    Large-gap metal oxides, such as titanium, tin, and zinc oxides, have attracted great interest because of their remarkable potential in dye-sensitized solar cells (DSSC) and their low cost and simple preparation procedure. In this work, we investigated several Zn-SnO{sub 2} and Cu-ZnO thin films that were sprayed under different experimental conditions. We varied [Zn/[Sn] and [Cu/[Zn] ratios, calculated on atomic percent in the starting solution. We report some structural results of the films using X-ray diffraction. Optical reflection and transmission spectra investigated by an UV/VIS/NIR spectrophotometer permit the determination of optical constants. The direct band gap was deduced from the photon energy dependence of the absorption coefficient.

  19. Highly durable superhydrophobic coatings with gradient density by movable spray method

    NASA Astrophysics Data System (ADS)

    Tenjimbayashi, Mizuki; Shiratori, Seimei

    2014-09-01

    Superhydrophobic surface is expected to be applied in anti-fouling, anti-icing, and anti-bacterial. However, practical use is interrupted by low mechanical strength, time-consuming process, and limited coating substrate. Here highly durable superhydrophobic coatings were prepared by simple and novel spraying method, which sprays with changing the "spray distance between substrate and spray" (SD), named "movable spray method." We prepared the solution that changes wettability and durability with spraying distance by mixing SiO2 nanoparticles and ethyl alpha cyanoacrylate polymer (EAC). Then, we evaluated the chemical components and surface morphologies of each spraying distance coatings (0 ˜ 50 cm) by XPS, SEM, and laser scanning microscope. It revealed that surface roughness and SiO2/EAC ratio increased as the SD increases. Thus, durable superhydrophobic coatings were designed by spraying with increasing SD gradually. Glow discharge-optical emission spectrometry analysis revealed that designed coatings showed the gradual increase of SiO2/EAC ratio. As a result, coatings prepared on glass, wood, or aluminum substrates maintained their superhydrophobicity up to the abrasion at 40 kPa. This movable spray method is simple coating by the wet process and prepares robust hydrophobic coating on complex shape and large area substrates. The gradient functional surface was found to have mechanical durability and superhydrophobicity, and wide area applications will be expected.

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

    USGS Publications Warehouse

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

    2012-01-01

    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.

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

    SciTech Connect

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

    2010-06-15

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

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

    DOEpatents

    Moore, Karen A.; Zatorski, Raymond A.

    2007-10-02

    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.

  3. Systems and methods for coating conduit interior surfaces utilizing a thermal spray gun with extension arm

    DOEpatents

    Moore, Karen A.; Zatorski, Raymond A.

    2005-07-12

    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.

  4. Investigations on MgO-dielectric GaN/AlGaN/GaN MOS-HEMTs by using an ultrasonic spray pyrolysis deposition technique

    NASA Astrophysics Data System (ADS)

    Lee, Ching-Sung; Hsu, Wei-Chou; Liu, Han-Yin; Wu, Ting-Ting; Sun, Wen-Ching; Wei, Sung-Yen; Yu, Sheng-Min

    2016-05-01

    This work investigates GaN/Al0.24Ga0.76N/GaN metal-oxide-semiconductor high electron mobility transistors (MOS-HEMTs) grown on a Si substrate with MgO gate dielectric by using the non-vacuum ultrasonic spray pyrolysis deposition (USPD) technique. The oxide layer thickness is tuned to be 30 nm with the dielectric constant of 8.8. Electron spectroscopy for chemical analysis (ESCA), secondary ion mass spectrometry (SIMS), atomic force microscopy (AFM), transmission electron microscopy (TEM), C-V, low-frequency noise spectra, and pulsed I-V measurements are performed to characterize the interface and oxide quality for the MOS-gate structure. Improved device performances have been successfully achieved for the present MOS-HEMT (Schottky-gate HEMT) design, consisting of a maximum drain-source current density (I DS, max) of 681 (500) mA/mm at V GS = 4 (2) V, I DS at V GS = 0 V (I DSS0) of 329 (289) mA/mm, gate-voltage swing (GVS) of 2.2 (1.6) V, two-terminal gate-drain breakdown voltage (BV GD) of -123 (-104) V, turn-on voltage (V on) of 1.7 (0.8) V, three-terminal off-state drain-source breakdown voltage (BV DS) of 119 (96) V, and on/off current ratio (I on/I off) of 2.5 × 108 (1.2 × 103) at 300 K. Improved high-frequency and power performances are also achieved in the present MOS-HEMT design.

  5. Characterization of a Heterostructure TiO2/SnO2:F/SUBSTRATE with Two Different Geometries, Prepared by Spray Pyrolysis to BE Used as Photocatalyst

    NASA Astrophysics Data System (ADS)

    Velázquez-Cruz, E. I.; Anaya-Castillejos, K. M.; Martínez-Martínez, R.; Soto-Guzmán, A. B.; Falcony, C.

    2013-07-01

    Two TiO2/SnO2:F/substrate hetero-structures (HS) with different geometry were deposited by spray pyrolysis. The thickness for the TiO2 and SnO2:F films was 3.8 μm and 2.3 μm, and the band gap energy 3.3 eV and 3.6 eV, respectively. Both films have a transmittance greater than 70% in most of the visible spectrum. The electrical resistivity of the SnO2:F film was ρ = (1.7)×10-4Ω ṡ cm. The surface morphology of the TiO2 film shows hemispheric agglomerates formed by nano-metric needle/platy shaped particles that give them a porous texture much like a "ball of wool," the length of the needles is from 100 nm and its thickness close to 20 nm. The geometry of HS has an important influence on its efficiency as photocatalyst under low-powered UV radiation. One of the geometry for this HS, in which the TiO2/SnO2:F interface is exposed, showed greater efficiency than the TiO2 and SnO2:F films separately, or than the common "sandwich" type HS geometry. Specifically, a decrease by 62% of the initial concentration of a watery solution of methylene blue (mb) of 20 ppm in approximately 5 h of UV radiation is observed for the exposed interface HS compared with less than 30% reduction observed for the common sandwich type HS.

  6. Method and apparatus for pyrolysis of atactic polypropylene

    DOEpatents

    Staffin, H.K.; Roaper, R.B.

    1986-09-23

    This invention relates to an apparatus and a method for pyrolytic decomposition of polymeric materials into lower molecular weight products involving the heat treatment of raw polymeric material within reactive conduits submerged in a fluidized bed furnace operated at pyrolyzing temperatures. 1 fig.

  7. Method and apparatus for pyrolysis of atactic polypropylene

    DOEpatents

    Staffin, H. Kenneth; Roaper, R. B.

    1986-09-23

    This invention relates to an apparatus and a method for pyrolytic decomposition of polymeric materials into lower molecular weight products involving the heat treatment of raw polymeric material within reactive conduits submerged in a fluidized bed furnace operated at pyrolizing temperatures.

  8. Spray vaccination: a method for the immunization of fish

    USGS Publications Warehouse

    Gould, R.W.; O'Leary, P. J.; Garrison, R. L.; Rohovec, J.S.; Fryer, J.L.

    1978-01-01

    The use of immunizing agents is emerging as a complement to other methods of disease control and has been used successfully both experimentally and commercially (FRYER et al., 1977). Two problems exist in the development of fish vaccines: first, to provide efficacious preparations; and second, to provide economic methods for mass vaccination. Vaccines for fish have been delivered by several methods to include: parenteral injection; orally, through incorporation of vaccines into the animal's diet; hyperosmotic infiltration, by placing fish in a hyperosmotic solution followed by a vaccine bath; direct immersion into vaccine suspensions; or by direct addition of vaccine to water in which fish are held (CORBEL, 1975; AMEND, 1976; AMEND and FENDER, 1976; SCHACTE, 1976; ANTIPA and AMEND, 1977; CROY and AMEND, 1977; FRYER, et al., 1977). Each of these techniques has its inherent advantages and disadvantages. Although intraperitoneal injection appears to be most effective, this method is time consuming and stresses the fish being vaccinated. Oral administration is perhaps the most desirable method of vaccine delivery, but in some cases has not provided high levels of resistance (GUNNELS, et al., 1976). Hyperosmotic infil tration and direct immersion are used to vac cinate small fish but may not be economical with larger animals. Addition of vaccine to water has been used experimentally only with an attenuated viral vaccine (FRYER et al., 1976). This report describes another method for mass immunization of fish. A bacterin against Vibrio anguillarum was administered by spraying fish with antigens prepared by selected methods. This technique provided a fast efficacious means of administering vibrio bacterin. 

  9. Method and apparatus for heat extraction by controlled spray cooling

    DOEpatents

    Edwards, Christopher Francis; Meeks, Ellen; Kee, Robert; McCarty, Kevin

    1999-01-01

    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.

  10. Microstructural, optical and electrical investigations of Sb-SnO{sub 2} thin films deposited by spray pyrolysis

    SciTech Connect

    Gupta, Sushant; Yadav, B.C.; Dwivedi, Prabhat K.; Das, B.

    2013-09-01

    Highlights: • We controlled structural, morphological, electrical, optical and physical (such as band gap energy) properties by altering the Sb doping concentration. • Variation in bandgap with Sb concentration is in agreement with the Burstein–Moss hypothesis and this hypothesis was further confirmed by plotting E{sub g} vs n{sup 2/3}. • The resistivity and mobility are in the range of 1.512–6.624 × 10{sup −3} Ω cm and 9.75–22.96 cm{sup 2} V{sup −1} s{sup −1}. The e-density lies between 4.11 × 10{sup 19} and 4.24 × 10{sup 20} cm{sup −3}. • We observed that Sb substitution in SnO{sub 2} lattice decreases the crystallite size and the possible reason for this is the creation of Sb monolayer on the surface of SnO{sub 2} crystallite. - Abstract: The structural, optical and electrical properties of spray deposited antimony (Sb) doped tin oxide (SnO{sub 2}) thin films, prepared from SnCl{sub 4} precursor, have been studied as a function of antimony doping concentration. The doping concentration was varied from 0 to 1.5 wt.% of Sb. The analysis of X-ray diffraction patterns revealed that the as deposited doped and undoped tin oxide thin films are pure crystalline tetragonal rutile phase of tin oxide which belongs to the space group P4{sub 2}/mnm (number 136). The surface morphological examination with field emission scanning electron microscopy (FESEM) revealed the fact that the grains are closely packed and pores/voids between the grains are very few. The resistivity (ρ) and mobility (μ) are in the range of 1.512 × 10{sup −3}–6.624 × 10{sup −3} Ω cm and 9.75–22.96 cm{sup 2} V{sup −1} s{sup −1}. The electron density lies between 4.11 × 10{sup 19} and 4.24 × 10{sup 20} cm{sup −3}. A thorough electrical investigation reveals that the film's resistivity depends on carrier concentration. It is found that ionized impurity scattering is the dominant mechanism, which limits the mobility of the carriers. The transmittance spectra for

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

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

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

  12. Effects of Concentration and Substrate Type on Structure and Conductivity of p-Type CuS Thin Films Grown by Spray Pyrolysis Deposition

    NASA Astrophysics Data System (ADS)

    Sabah, Fayroz A.; Ahmed, Naser M.; Hassan, Z.

    2016-09-01

    Copper sulphide (CuS) thin films were grown upon Ti, indium tin oxide (ITO), and glass substrates by using spray pyrolysis deposition at 200°C. The films exhibited good adhesion compared to chemical bath deposition. CuCl2·2H2O and Na2S2O3·5H2O precursors were used as Cu2+ and S2- sources, respectively. Two concentrations (i.e., 0.2 M and 0.4 M) were selected in this study. X-ray diffraction analysis reveals that the films with 0.2 M showed only the formation of a covellite CuS phase having a hexagonal crystal structure with diffraction peaks of low intensity. For 0.4 M concentration, in addition to the covellite CuS phase, chalcocite Cu2S phase having a hexagonal crystal structure also appeared with relatively higher intensity peaks for all thin films. Field-emission scanning electron microscopy observations showed the formation of small grains for 0.2 M, whereas a mixture of grains with square-like shape and nanoplates were formed for 0.4 M. Depending on the 0.2 M and 0.4 M thin films thicknesses (3.2 μm and 4 μm, respectively), the band gap energy was obtained from optical measurements to be approximately 2.64 eV for 0.2 M (pure CuS phase), which slightly decreased up to 2.56 eV for 0.4 M concentration. Hall effect measurements showed that all grown films are p-type. The 0.2 M film exhibited much lower sheet resistance (R sh = 33.96 Ω/Sq-55.70 Ω/Sq) compared to 0.4 M film (R sh = 104.33 Ω/Sq-466.6 Ω/Sq). Moreover, for both concentrations, the films deposited onto ITO substrate showed the lowest sheet resistance (R sh = 33.96 Ω/Sq-104.33 Ω/Sq).

  13. Investigation of adsorption properties of alumina produced by vacuum spray method

    NASA Astrophysics Data System (ADS)

    Khrustaleva, K.; Voronova, G.

    2016-02-01

    In this paper nanopowders obtained by vacuum spray method were studied. The phase composition of the obtained powders is γ - Al2O3. Obtained nanopowders have specific surface area about 200 m2/g. Adsorptive properties of these powders were studied by static adsorption from solutions. The anionic dye eosin was selected as adsorbate. It has been found that the powders obtained by vacuum spray method have significant capacity to adsorb eosin.

  14. Investigating pyrolysis/incineration as a method of resource recovery from solid waste

    NASA Technical Reports Server (NTRS)

    Robertson, Bobby J.; Lemay, Christopher S.

    1993-01-01

    Pyrolysis/incineration (P/I) is a physicochemical method for the generation of recoverable resources from solid waste materials such as inedible plant biomass (IPB), paper, plastics, cardboard, etc. P/I permits the collection of numerous gases with a minimal amount of solid residue. Pyrolysis, also known as starved air incineration, is usually conducted at relatively high temperatures (greater than 500 deg C) in the absence of oxygen. Incineration is conducted at lower temperatures in the presence of oxygen. The primary purpose of this study was to design, construct, and test a model P/I. The system design includes safety requirements for temperature and pressure. The objectives of this study were: (1) to design and construct a P/I system for incorporation with the Hybrid Regenerative Water Recovery System; (2) to initiate testing of the P/I system; (3) to collect and analyze P/I system data; (4) to consider test variables; and (5) to determine the feasibility of P/I as an effective method of resource recovery. A P/I system for the recovery of reuseable resources from solid waste materials was designed, constructed, and tested. Since a large amount of inedible plant biomass (IPB) will be generated in a space-based habitat on the lunar surface and Mars, IPB was the primary waste material tested in the system. Analysis of the effluent gases was performed to determine which gases could be used in a life support system.

  15. Characterization of carbon silica hybrid fillers obtained by pyrolysis of waste green tires by the STEM–EDX method

    SciTech Connect

    Al-Hartomy, Omar A.; Al-Ghamdi, Ahmed A.; Al Said, Said A. Farha; Dishovsky, Nikolay; Ward, Michael B.; Mihaylov, Mihail; Ivanov, Milcho

    2015-03-15

    Dual phase carbon–silica hybrid fillers obtained by pyrolysis-cum-water vapor of waste green tires have been characterized by energy dispersive X-ray spectroscopy in a scanning transmission electron microscope, silicate analysis, weight analysis, atomic absorption spectroscopy and by inductively coupled plasma–optical emission spectroscopy. The results achieved have shown that the location and distribution of the phases in the carbon silica hybrid fillers as well as their most essential characteristics are influenced by the pyrolysis conditions. The carbon phase of the filler thus obtained is located predominantly in the space among silica aggregates which have already been existing while it has been formed by elastomer destruction in the course of pyrolysis. The presence of ZnS also has been found in the hybrid fillers investigated. - Highlights: • Dual phase fillers obtained by pyrolysis of waste green tires have been characterized. • The STEM–EDX method was used for characterization. • The phase distributions in the fillers are influenced by the pyrolysis conditions.

  16. Method and apparatus for the application of thermal spray coatings onto aluminum engine cylinder bores

    SciTech Connect

    Byrnes, L.; Kramer, M.

    1994-12-31

    This paper presents background and detail information concerning the application of thermally sprayed metal alloy coatings onto the I.D. surfaces of aluminum block engine cylinder bores using a rotating extension HVOF spray gun. A fixturing method that provides block temperature stabilization and the elimination of fixture cleaning and part masking is described. A new approach and technique that replaces grit blasting for surface preparation is also discussed.

  17. In Situ Monitoring of Plasma Spraying Process by Laser Acoustic Emission Method

    NASA Astrophysics Data System (ADS)

    Ito, Kaita; Enoki, Manabu; Watanabe, Makoto; Kuroda, Seiji

    Estimation of microfractures in ceramic coating layer during plasma spraying process is critical for its reliability. Acoustic emission (AE) method enables in-process monitoring of such microfractures. Laser AE method was adopted to realize the monitoring of plasma spraying process by non-contact detection of AE with laser interferometer. Also a high performance method for noise reduction of laser AE waveform was investigated. In this new method, laser AE signal was continuously sampled and transformed into spectrogram by time-frequency analysis to cut out noise component effectively. After this noise reduction process, inverse transform was applied to obtain a clear AE signals in time domain. Whole these processes can be done in real time. The effectiveness of this method was confirmed by a detection test of simulated AE and successfully applied to the monitoring of plasma spraying process. Two types of AE events with different duration time range were found and the sources of these AE were presumed.

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

    PubMed

    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

    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.

  19. Multiphase and Double-Layer NiFe2O4@NiO-Hollow-Nanosphere-Decorated Reduced Graphene Oxide Composite Powders Prepared by Spray Pyrolysis Applying Nanoscale Kirkendall Diffusion.

    PubMed

    Park, Gi Dae; Cho, Jung Sang; Kang, Yun Chan

    2015-08-01

    Multicomponent metal oxide hollow-nanosphere decorated reduced graphene oxide (rGO) composite powders are prepared by spray pyrolysis with nanoscale Kirkendall diffusion. The double-layer NiFe2O4@NiO-hollow-nanosphere decorated rGO composite powders are prepared using the first target material. The NiFe-alloy-nanopowder decorated rGO powders are prepared as an intermediate product by post-treatment under the reducing atmosphere of the NiFe2O4/NiO-decorated rGO composite powders obtained by spray pyrolysis. The different diffusion rates of Ni (83 pm for Ni(2+)) and Fe (76 pm for Fe(2+), 65 pm for Fe(3+)) cations with different radii during nanoscale Kirkendall diffusion result in multiphase and double-layer NiFe2O4@NiO hollow nanospheres. The mean size of the hollow NiFe2O4@NiO nanospheres decorated uniformly within crumpled rGO is 14 nm. The first discharge capacities of the nanosphere-decorated rGO composite powders with filled NiFe2O4/NiO and hollow NiFe2O4@NiO at a current density of 1 A g(-1) are 1168 and 1319 mA h g(-1), respectively. Their discharge capacities for the 100th cycle are 597 and 951 mA h g(-1), respectively. The discharge capacity of the NiFe2O4@NiO-hollow-nanosphere-decorated rGO composite powders at the high current density of 4 A g(-1) for the 400th cycle is 789 mA h g(-1).

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

    SciTech Connect

    Hui-Jun Won; Chong-Hun Jung; Jei-Kwon Moon

    2008-01-15

    The characteristics of per-fluorocarbon compounds (PFC) are colorless, non-toxic, easily vaporized and nonflammable. Also, some of them are liquids of a high density, low surface tension, low latent heat and low specific heat. These particular chemical and physical properties of fluoro-organic compounds permit their use in very different fields such as electronics, medicine, tribology, nuclear and material science. The Sonatol process was developed under a contract with the DOE. The Sonatol process uses an ultrasonic agitation in a PFC solution that contains a fluorinated surfactant to remove radioactive particles from surfaces. Filtering the suspended particles allows the solutions to be reused indefinitely. They applied the Sonatol process to the decontamination of a heterogeneous legacy Pu-238 waste that exhibited an excessive hydrogen gas generation, which prevents a transportation of such a waste to a Waste Isolation Pilot Plant. Korea Atomic Energy Research Institute (KAERI) is developing dry decontamination technologies applicable to a decontamination of a highly radioactive area loosely contaminated with radioactive particles. This contamination has occurred as a result of an examination of a post-irradiated material or the development of the DUPIC process. The dry decontamination technologies developed are the carbon dioxide pellet spray method and the PFC spray method. As a part of the project, PFC ultrasonic decontamination technology was developed in 2004. The PFC spray decontamination method which is based on the test results of the PFC ultrasonic method has been under development since 2005. The developed PFC spray decontamination equipment consists of four modules (spray, collection, filtration and distillation). Vacuum cup of the collection module gathers the contaminated PFC solution, then the solution is moved to the filtration module and it is recycled. After a multiple recycling of the spent PFC solution, it is purified in the distillation

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

    NASA Astrophysics Data System (ADS)

    Smakulski, Przemysław

    2013-09-01

    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.

  2. Study of the influence of substrate temperature on structural, optical, and electrical properties of Zn-doped MnIn2S4 thin films prepared by chemical spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Kennedy, A.; Viswanathan, K.; Pradeev raj, K.

    2016-08-01

    The Zn-doped MnIn2S4 thin films were deposited by chemical spray pyrolysis technique on a heated glass substrate using the aqueous solution of MnCl2, InCl3, (NH2)2CS and ZnCl2. The thin films were grown at different substrate temperatures ranging from 250-400 °C. The synthesized films were characterized by X-ray diffraction (XRD), energy dispersive analysis spectrum (EDS), field emission scanning electron microscope (FESEM), UV-Vis absorption spectroscopy and four probe method. The XRD analysis indicates Zn-doped MnIn2S4 thin films were polycrystalline in nature with a cubic spinel structure having (101) plane as the preferred orientation. The structural parameters like crystalline size (D), dislocation density (δ), strain (ε) and lattice distortion (LD) have been evaluated from XRD results. The energy dispersive analysis spectrum (EDS) predicts the presence of Mn, In, S and Zn in the film grown at 250 °C. The formation of the needle and spherical shaped grains was clearly observed from FE-SEM analysis. From the optical studies, it is analyzed that about (88%) of light transmission occurs in the Vis-IR regions. It is interesting to note that the structural homogeneity and crystallinity of the films has improved due to the decrease in the absorption coefficient (α) and extinction coefficient (K) with an increase in substrate temperature. The calculated optical band gap energies increase (1.51-1.74 eV) with an increase of substrate temperatures. The photoluminescence (PL) spectrum reveals the presence of well-defined band edge (<400 nm) and defect emissions in the wavelength region around 400-650 nm. Moreover, from electrical studies, the electrical resistivity decreases with increase in substrate temperature and a minimum electrical resistivity of 1.20 ×103 Ωm was obtained for the film coated at 400 °C. The high absorption coefficient (α) in the order of 104cm-1 and high transmittance (88%) of the films makes them an efficient absorber and a good window

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

    NASA Astrophysics Data System (ADS)

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

    2007-03-01

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

  4. Spray cooling simulation implementing time scale analysis and the Monte Carlo method

    NASA Astrophysics Data System (ADS)

    Kreitzer, Paul Joseph

    Spray cooling research is advancing the field of heat transfer and heat rejection in high power electronics. Smaller and more capable electronics packages are producing higher amounts of waste heat, along with smaller external surface areas, and the use of active cooling is becoming a necessity. Spray cooling has shown extremely high levels of heat rejection, of up to 1000 W/cm 2 using water. Simulations of spray cooling are becoming more realistic, but this comes at a price. A previous researcher has used CFD to successfully model a single 3D droplet impact into a liquid film using the level set method. However, the complicated multiphysics occurring during spray impingement and surface interactions increases computation time to more than 30 days. Parallel processing on a 32 processor system has reduced this time tremendously, but still requires more than a day. The present work uses experimental and computational results in addition to numerical correlations representing the physics occurring on a heated impingement surface. The current model represents the spray behavior of a Spraying Systems FullJet 1/8-g spray nozzle. Typical spray characteristics are indicated as follows: flow rate of 1.05x10-5 m3/s, normal droplet velocity of 12 m/s, droplet Sauter mean diameter of 48 microm, and heat flux values ranging from approximately 50--100 W/cm2 . This produces non-dimensional numbers of: We 300--1350, Re 750--3500, Oh 0.01--0.025. Numerical and experimental correlations have been identified representing crater formation, splashing, film thickness, droplet size, and spatial flux distributions. A combination of these methods has resulted in a Monte Carlo spray impingement simulation model capable of simulating hundreds of thousands of droplet impingements or approximately one millisecond. A random sequence of droplet impingement locations and diameters is generated, with the proper radial spatial distribution and diameter distribution. Hence the impingement, lifetime

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

    PubMed

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

    2012-10-01

    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.

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

    NASA Technical Reports Server (NTRS)

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

    2007-01-01

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

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

    DOEpatents

    McIntosh, Michael J.; Arzoumanidis, Gregory G.

    1997-01-01

    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.

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

    SciTech Connect

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

    1997-09-02

    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.

  9. A method and system including a double rotary kiln pyrolysis or gasification of waste material

    SciTech Connect

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

    1995-12-31

    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.

  10. Feasibility of soil dust source apportionment by the pyrolysis-gas chromatography/mass spectrometry method.

    PubMed

    Labban, Raed; Veranth, John M; Watson, John G; Chow, Judith C

    2006-09-01

    This study tested the feasibility of using pyrolysis (Py)-gas chromatography (GC)/mass spectrometry (MS) to obtain organic chemical species data suitable for source apportionment modeling of soil-derived coarse particulate matter (PM10) dust on ambient filters. A laboratory resuspension apparatus was used with known soils to generate simulated receptor filter samples loaded with approximately 0.4 mg of PM10 dust, which is within the range of mass loading on ambient filters. Py-GC/MS at 740 degrees C generated five times more resolvable compounds than were obtained with thermal desorption GC/MS at 315 degrees C. The identified compounds were consistent with literature from Py experiments using larger samples of bulk soils. A subset of 91 organic species out of the 178 identified Py products was used as input to CMB8 software in a demonstration of source apportionment using laboratory-generated mixtures simulating ambient filter samples. The 178 quantified organic species obtained by Py of soil samples is an improvement compared with the 38 organic species obtained by thermal desorption of soils and the four functionally defined organic fractions reported by thermal/ optical reflectance. Significant differences in the concentration of specific species were seen between samples from different sites, both geographically distant and close, using analysis of variance and cluster analysis. This feasibility study showed that Py-GC/MS can generate useful source profile data for receptor modeling and justifies continued method development.

  11. 10 CFR 431.264 - Uniform test method for the measurement of flow rate for commercial prerinse spray valves.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Valves Test Procedures § 431.264 Uniform test method for the measurement of flow rate for commercial..., the water consumption flow rate of commercial prerinse spray valves. (b) Testing and Calculations. The test procedure to determine the water consumption flow rate for prerinse spray valves, expressed...

  12. 10 CFR 431.264 - Uniform test method for the measurement of flow rate for commercial prerinse spray valves.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Valves Test Procedures § 431.264 Uniform test method for the measurement of flow rate for commercial..., the water consumption flow rate of commercial prerinse spray valves. (b) Testing and Calculations. The test procedure to determine the water consumption flow rate for prerinse spray valves, expressed...

  13. Analytical methods to characterize heterogeneous raw material for thermal spray process: cored wire Inconel 625

    NASA Astrophysics Data System (ADS)

    Lindner, T.; Bonebeau, S.; Drehmann, R.; Grund, T.; Pawlowski, L.; Lampke, T.

    2016-03-01

    In wire arc spraying, the raw material needs to exhibit sufficient formability and ductility in order to be processed. By using an electrically conductive, metallic sheath, it is also possible to handle non-conductive and/or brittle materials such as ceramics. In comparison to massive wire, a cored wire has a heterogeneous material distribution. Due to this fact and the complex thermodynamic processes during wire arc spraying, it is very difficult to predict the resulting chemical composition in the coating with sufficient accuracy. An Inconel 625 cored wire was used to investigate this issue. In a comparative study, the analytical results of the raw material were compared to arc sprayed coatings and droplets, which were remelted in an arc furnace under argon atmosphere. Energy-dispersive X-ray spectroscopy (EDX) and X-ray fluorescence (XRF) analysis were used to determine the chemical composition. The phase determination was performed by X-ray diffraction (XRD). The results were related to the manufacturer specifications and evaluated in respect to differences in the chemical composition. The comparison between the feedstock powder, the remelted droplets and the thermally sprayed coatings allows to evaluate the influence of the processing methods on the resulting chemical and phase composition.

  14. Effect of pyrolysis temperature on the properties of carbon/nickel nanocomposites prepared by sol-gel method

    NASA Astrophysics Data System (ADS)

    Mansour, N. Ben; Najeh, I.; Mansouri, S.; El Mir, L.

    2015-05-01

    Carbon-nickel nanocomposites (C/Ni) were prepared by sol-gel method after the incorporation of nickel oxide (NiO) nanoparticles in organic matrix based on pyrogallol-formaldehyde (PF). The nanocomposites heated under inert atmosphere have been characterized by various techniques such as X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), and electrical analysis. The XRD spectra exhibited the presence of NiO or metallic Ni phase in amorphous carbon matrix at low pyrolysis temperature, while at 1000 °C the graphite structure line was observed. The TEM images indicate the presence of multiwall carbon nanotubes (MWNT) around Ni nanoparticles for the sample treated at high pyrolysis temperature. The AC conductance shows that our nanocomposites have two behaviors: semiconductor and metal, depending on the pyrolysis temperature. The voltage-current V(I) characteristics of the compound show two different regions: an Ohmic region at low current and a negative differential resistance (NDR) region at higher current. This switching phenomenal behavior has been explained by an electrothermal model.

  15. Formate-assisted pyrolysis

    DOEpatents

    DeSisto, William Joseph; Wheeler, Marshall Clayton; van Heiningen, Adriaan R. P.

    2015-03-17

    The present invention provides, among other thing, methods for creating significantly deoxygenated bio-oils form biomass including the steps of providing a feedstock, associating the feedstock with an alkali formate to form a treated feedstock, dewatering the treated feedstock, heating the dewatered treated feedstock to form a vapor product, and condensing the vapor product to form a pyrolysis oil, wherein the pyrolysis oil contains less than 30% oxygen by weight.

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

    SciTech Connect

    Wang, Rongguang; Kido, Mitsuo

    2003-07-14

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

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

    USGS Publications Warehouse

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

    1983-01-01

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

  18. Confined-pyrolysis as an experimental method for hydrothermal organic synthesis.

    PubMed

    Leif, R N; Simoneit, B R

    1995-10-01

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

  19. Confined-Pyrolysis as an Experimental Method for Hydrothermal Organic Synthesis

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

    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.

  20. Analysis of Biological Samples Using Paper Spray Mass Spectrometry: An Investigation of Impacts by the Substrates, Solvents and Elution Methods

    PubMed Central

    Ren, Yue; Wang, He; Liu, Jiangjiang; Zhang, Zhiping; McLuckey, Morgan N.; Ouyang, Zheng

    2013-01-01

    Paper spray has been developed as a fast sampling ionization method for direct analysis of raw biological and chemical samples using mass spectrometry (MS). Quantitation of therapeutic drugs in blood samples at high accuracy has also been achieved using paper spray MS without traditional sample preparation or chromatographic separation. The paper spray ionization is a process integrated with a fast extraction of the analyte from the raw sample by a solvent, the transport of the extracted analytes on the paper, and a spray ionization at the tip of the paper substrate with a high voltage applied. In this study, the influence on the analytical performance by the solvent-substrate systems and the selection of the elution methods was investigated. The protein hemoglobin could be observed from fresh blood samples on silanized paper or from dried blood spots on silica-coated paper. The on-paper separation of the chemicals during the paper spray was characterized through the analysis of a mixture of the methyl violet 2B and methylene blue. The mode of applying the spray solvent was found to have a significant impact on the separation. The results in this study led to a better understanding of the analyte elution, on-paper separation, as well as the ionization processes of the paper spray. This study also help to establish a guideline for optimizing the analytical performance of paper spray for direct analysis of target analytes using mass spectrometry. PMID:24072932

  1. δ18O analysis of individual carbohydrates - a new method for GC-pyrolysis-IRMS

    NASA Astrophysics Data System (ADS)

    Lehmann, Marco M.; Fischer, Maria; Zech, Michael; Siegwolf, Rolf T. W.; Saurer, Matthias

    2015-04-01

    Measuring the oxygen isotopic composition (δ18O) of various plant tissues is a widely used tool to investigate biochemical and physiological processes. While we have a good understanding about the hydrological cycle in plants with an evaporative enrichment in 18O in leaf water, we still lack knowledge about the biochemical link between the oxygen atoms in leaf water, leaf assimilates, and stem cellulose and associated isotope fractionations. Especially, the influence of different environmental factors on δ18O of individual carbohydrates (i.e. sugars) and thus on δ18O of cellulose is not fully resolved. A better understanding of these processes may improve climatic reconstructions of tree-ring studies about past environmental conditions. However, further progress in this topic is limited since a precise and reliable method to determine δ18O of individual sugars has not been available yet. With our new approach we attempt to overcome this issue by establishing a new methylation derivatization method suitable for GC-pyrolysis -IRMS. A methyl group (CH3) was thereby added to all hydroxyl groups of a sugar (e.g., glucose, fructose, and sucrose) during a catalyzed one-pot reaction overnight in acetonitrile with methyl iodide (CH3-I) and silver oxide, making them amenable for GC analysis. First results show a very good precision for δ18O of sucrose, but also δ18O of other high-abundant sugars such as glucose and fructose could be measured for the first time. We successfully analyzed a standard mix of all three sugars and determined various other carbohydrates not only related to plant sciences (e.g. mannitol, lactose), showing promising δ18O results. First tests with real plant samples were performed to make this method available for determining δ18O of individual carbohydrates of diverse plant tissues. In future, this new methylation derivatization method should allow us analyzing plant samples of different field sites and of lab experiments to investigate the

  2. Hollow and porous hydroxyapatite microspheres prepared with an O/W emulsion by spray freezing method.

    PubMed

    Xiao, Qiyao; Zhou, Kechao; Chen, Chao; Jiang, Mingxiang; Zhang, Yan; Luo, Hang; Zhang, Dou

    2016-12-01

    Microspheres with hollow and/or porous structures have been widely used in various applications. A new method of spraying and freezing emulsions was developed to prepare hollow HA (hydroxyapatite) microspheres with interconnected pores by using PVA (polyvinyl alcohol) as emulsifiers and binders. The relationships between viscosity and shear time or rates were tested and the dispersing stability of oil in water (O/W) emulsions was characterized with comparison to suspensions without the addition of oil phase. The effects of solid loadings of HA and the volume ratio between oil and water on the morphologies of microspheres were investigated. Hollow HA microspheres with particle diameter of ~20μm and pore size of ~0.6μm were successfully obtained by spray freezing method. Besides, drying and sintering processes were crucial to the formation of hollow and porous structures, respectively. The gentamicin loading and releasing of HA porous microspheres with different hollow volumes were tested.

  3. Hollow and porous hydroxyapatite microspheres prepared with an O/W emulsion by spray freezing method.

    PubMed

    Xiao, Qiyao; Zhou, Kechao; Chen, Chao; Jiang, Mingxiang; Zhang, Yan; Luo, Hang; Zhang, Dou

    2016-12-01

    Microspheres with hollow and/or porous structures have been widely used in various applications. A new method of spraying and freezing emulsions was developed to prepare hollow HA (hydroxyapatite) microspheres with interconnected pores by using PVA (polyvinyl alcohol) as emulsifiers and binders. The relationships between viscosity and shear time or rates were tested and the dispersing stability of oil in water (O/W) emulsions was characterized with comparison to suspensions without the addition of oil phase. The effects of solid loadings of HA and the volume ratio between oil and water on the morphologies of microspheres were investigated. Hollow HA microspheres with particle diameter of ~20μm and pore size of ~0.6μm were successfully obtained by spray freezing method. Besides, drying and sintering processes were crucial to the formation of hollow and porous structures, respectively. The gentamicin loading and releasing of HA porous microspheres with different hollow volumes were tested. PMID:27612804

  4. Thin nanostructured LiMn 2O 4 films by flame spray deposition and in situ annealing method

    NASA Astrophysics Data System (ADS)

    Chew, S. Y.; Patey, T. J.; Waser, O.; Ng, S. H.; Büchel, R.; Tricoli, A.; Krumeich, F.; Wang, J.; Liu, H. K.; Pratsinis, S. E.; Novák, P.

    A new approach has been developed to rapidly synthesize nanostructured LiMn 2O 4 thin films by flame spray deposition (FSD) and in situ annealing. A precursor solution of lithium acetylacetonate and manganese acetylacetonate in an organic solution was supplied through a flame spray pyrolysis (FSP) reactor. The liquid solution spray was ignited and stabilized by a premixed methane/oxygen flame ring surrounding the FSP nozzle. Thus, LiMn 2O 4 nanoparticles were formed by combustion and deposited onto a current collector followed by in situ annealing. Two different types of current collectors, i.e. stainless steel and aluminum coated with carbon-based primer were tested. The prepared thin films were characterized by X-ray diffraction and field-emission scanning electron microscopy. The electrochemical properties of the thin films were evaluated by cyclic voltammetry and galvanostatic cycling. The LiMn 2O 4 films exhibited good cyclability. Films that underwent sintering and crystal growth during in situ annealing developed more robust film structures on the current collector surface and exhibited better electrochemical performance than poorly adhered films.

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

    PubMed

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

    2012-12-21

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

    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.

  7. Numerical Modeling of Spray Combustion with an Unstructured-Grid Method

    NASA Technical Reports Server (NTRS)

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

    1996-01-01

    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.

  8. Transparent conductive PVP/AgNWs films for flexible organic light emitting diodes by spraying method

    NASA Astrophysics Data System (ADS)

    Hu, Jun-tao; Mei, Wen-juan; Ye, Kang-li; Wei, Qing-qing; Hu, Sheng

    2016-05-01

    In this study, a simple spraying method is used to prepare the transparent conductive films (TCFs) based on Ag nanowires (AgNWs). Polyvinylpyrrolidone (PVP) is introduced to modify the interface of substrate. The transmittance and bending performance are improved by optimizing the number of spraying times and the solution concentration and controlling the annealing time. The spraying times of 20, the concentration of 2 mg/mL and the annealing time of 10 min are chosen to fabricate the PVP/AgNWs films. The transmittance of PVP/AgNWs films is 53.4%—67.9% at 380—780 nm, and the sheet resistance is 30 Ω/□ which is equivalent to that of commercial indium tin oxide (ITO). During cyclic bending tests to 500 cycles with bending radius of 5 mm, the changes of resistivity are negligible. The performance of PVP/AgNW transparent electrodes has little change after being exposed to the normal environment for 1 000 h. The adhesion to polymeric substrate and the ability to endure bending stress in AgNWs network films are both significantly improved by introducing PVP. Spraying method makes AgNWs form a stratified structure on large-area polymer substrates, and the vacuum annealing method is used to weld the AgNWs together at junctions and substrates, which can improve the electrical conductivity. The experimental results indicate that PVP/AgNW transparent electrodes can be used as transparent conductive electrodes in flexible organic light emitting diodes (OLEDs).

  9. Response surface method for evaluation of the performance of agricultural application spray nozzles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Droplet size, being one of the critical factors that influences spray performance and drift, must be considered when selecting spray nozzles and operational setups. Characterizing a spray nozzle for droplet size is typically completed by evaluating arbitrary nozzle type, size and spray pressure. H...

  10. Evaluation of a Consistent LES/PDF Method Using a Series of Experimental Spray Flames

    NASA Astrophysics Data System (ADS)

    Heye, Colin; Raman, Venkat

    2012-11-01

    A consistent method for the evolution of the joint-scalar probability density function (PDF) transport equation is proposed for application to large eddy simulation (LES) of turbulent reacting flows containing evaporating spray droplets. PDF transport equations provide the benefit of including the chemical source term in closed form, however, additional terms describing LES subfilter mixing must be modeled. The recent availability of detailed experimental measurements provide model validation data for a wide range of evaporation rates and combustion regimes, as is well-known to occur in spray flames. In this work, the experimental data will used to investigate the impact of droplet mass loading and evaporation rates on the subfilter scalar PDF shape in comparison with conventional flamelet models. In addition, existing model term closures in the PDF transport equations are evaluated with a focus on their validity in the presence of regime changes.

  11. An exploration of the cold gas-dynamic spray method for several materials systems

    SciTech Connect

    McCune, R.C.; Papyrin, A.N.; Hall, J.N.; Riggs, W.L. II; Zajchowski, P.H.

    1995-12-31

    This paper reports activities of a consortium of companies formed under the aegis of the National Center for Manufacturing Sciences (NCMS) to explore a cold gas-dynamic spray method (CGSM) developed in Russia by Alkhimov, Papyrin and coworkers. In this spray process metal powder particles develop into a coating as a result of ballistic impingement on a suitable substrate. In some instances, surface preparation of the substrate using such traditional methods as grit blasting is unnecessary. The spray nozzle used in this process has been designed so as to permit introduction of powder particles into a preheated gas stream which is then rendered supersonic by expansion through a converging-diverging throat, with accompanying temperature reduction. Thus, the temperature of the gas stream is always below the melting point of the particulate material, providing coatings developed primarily from particles in the solid state. The fundamentals of CGSM are reviewed and results from several material combinations explored in the first phase of the research program are presented. Experimental coatings including copper on alumina ceramic, steel on cast aluminum, and a chromium carbide composite on titanium were produced. Typical microstructures, porosity, adhesion, and physical characteristics of these coatings are discussed.

  12. Novel method for the measurement of liquid film thickness during fuel spray impingement on surfaces.

    PubMed

    Henkel, S; Beyrau, F; Hardalupas, Y; Taylor, A M K P

    2016-02-01

    This paper describes the development and application of a novel optical technique for the measurement of liquid film thickness formed on surfaces during the impingement of automotive fuel sprays. The technique makes use of the change of the light scattering characteristics of a metal surface with known roughness, when liquid is deposited. Important advantages of the technique over previously established methods are the ability to measure the time-dependent spatial distribution of the liquid film without a need to add a fluorescent tracer to the liquid, while the measurement principle is not influenced by changes of the pressure and temperature of the liquid or the surrounding gas phase. Also, there is no need for non-fluorescing surrogate fuels. However, an in situ calibration of the dependence of signal intensity on liquid film thickness is required. The developed method can be applied to measure the time-dependent and two-dimensional distribution of the liquid fuel film thickness on the piston or the liner of gasoline direct injection (GDI) engines. The applicability of this technique was evaluated with impinging sprays of several linear alkanes and alcohols with different thermo-physical properties. The surface temperature of the impingement plate was controlled to simulate the range of piston surface temperatures inside a GDI engine. Two sets of liquid film thickness measurements were obtained. During the first set, the surface temperature of the plate was kept constant, while the spray of different fuels interacted with the surface. In the second set, the plate temperature was adjusted to match the boiling temperature of each fuel. In this way, the influence of the surface temperature on the liquid film created by the spray of different fuels and their evaporation characteristics could be demonstrated. PMID:26906828

  13. An in vitro method for predicting inhalation toxicity of impregnation spray products.

    PubMed

    Sørli, Jorid B; Hansen, Jitka S; Nørgaard, Asger W; Levin, Marcus; Larsen, Søren T

    2015-01-01

    Impregnation spray products are used for making surfaces water and dirt repellent. The products are composed of one or more active film-forming components dissolved or suspended in an appropriate solvent mixture. Exposure to impregnation spray products may cause respiratory distress and new cases are reported frequently. The toxicity appears to be driven by a disruption of the pulmonary surfactant film, which coats the inside of the lungs. Due to the complex chemistry of impregnation spray products, it is impossible to predict if inhalation of an aerosolized product is toxic in vivo. The aim of this study was to evaluate whether disruption of the pulmonary surfactant film can be used as a predictor of the toxic effects in vivo. Nine impregnation products with various chemical compositions were selected for testing and the main constituents of each product, e.g., solvents, co-solvents and film-forming compounds, were identified by mass spectrometry. We used a capillary surfactometry method to assess disruption of pulmonary surfactant function in vitro and a mouse model to evaluate acute respiratory toxicity during inhalation. Concentration-response relationships were successfully determined both in vitro and in vivo. The true positive rate of the in vitro method was 100%, i.e. the test could correctly identify all products with toxic effects in vivo, the true negative rate was 40%. Investigation of inhibition of the pulmonary surfactant system, e.g. by capillary surfactometry, was found useful for evaluation of the inhalation toxicity of impregnation spray products and thus may reduce the need for animal testing.

  14. An in vitro method for predicting inhalation toxicity of impregnation spray products.

    PubMed

    Sørli, Jorid B; Hansen, Jitka S; Nørgaard, Asger W; Levin, Marcus; Larsen, Søren T

    2015-01-01

    Impregnation spray products are used for making surfaces water and dirt repellent. The products are composed of one or more active film-forming components dissolved or suspended in an appropriate solvent mixture. Exposure to impregnation spray products may cause respiratory distress and new cases are reported frequently. The toxicity appears to be driven by a disruption of the pulmonary surfactant film, which coats the inside of the lungs. Due to the complex chemistry of impregnation spray products, it is impossible to predict if inhalation of an aerosolized product is toxic in vivo. The aim of this study was to evaluate whether disruption of the pulmonary surfactant film can be used as a predictor of the toxic effects in vivo. Nine impregnation products with various chemical compositions were selected for testing and the main constituents of each product, e.g., solvents, co-solvents and film-forming compounds, were identified by mass spectrometry. We used a capillary surfactometry method to assess disruption of pulmonary surfactant function in vitro and a mouse model to evaluate acute respiratory toxicity during inhalation. Concentration-response relationships were successfully determined both in vitro and in vivo. The true positive rate of the in vitro method was 100%, i.e. the test could correctly identify all products with toxic effects in vivo, the true negative rate was 40%. Investigation of inhibition of the pulmonary surfactant system, e.g. by capillary surfactometry, was found useful for evaluation of the inhalation toxicity of impregnation spray products and thus may reduce the need for animal testing. PMID:25651757

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

    NASA Astrophysics Data System (ADS)

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

    2012-06-01

    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.

  16. Novel method for the measurement of liquid film thickness during fuel spray impingement on surfaces.

    PubMed

    Henkel, S; Beyrau, F; Hardalupas, Y; Taylor, A M K P

    2016-02-01

    This paper describes the development and application of a novel optical technique for the measurement of liquid film thickness formed on surfaces during the impingement of automotive fuel sprays. The technique makes use of the change of the light scattering characteristics of a metal surface with known roughness, when liquid is deposited. Important advantages of the technique over previously established methods are the ability to measure the time-dependent spatial distribution of the liquid film without a need to add a fluorescent tracer to the liquid, while the measurement principle is not influenced by changes of the pressure and temperature of the liquid or the surrounding gas phase. Also, there is no need for non-fluorescing surrogate fuels. However, an in situ calibration of the dependence of signal intensity on liquid film thickness is required. The developed method can be applied to measure the time-dependent and two-dimensional distribution of the liquid fuel film thickness on the piston or the liner of gasoline direct injection (GDI) engines. The applicability of this technique was evaluated with impinging sprays of several linear alkanes and alcohols with different thermo-physical properties. The surface temperature of the impingement plate was controlled to simulate the range of piston surface temperatures inside a GDI engine. Two sets of liquid film thickness measurements were obtained. During the first set, the surface temperature of the plate was kept constant, while the spray of different fuels interacted with the surface. In the second set, the plate temperature was adjusted to match the boiling temperature of each fuel. In this way, the influence of the surface temperature on the liquid film created by the spray of different fuels and their evaporation characteristics could be demonstrated.

  17. 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)

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

    2013-01-01

    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.

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

    PubMed

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

    2010-02-01

    The subject of our investigations was the process of obtaining alginate/chitosan polyelectrolyte complex (PEC) fibers. In this study, a novel method named "spray-spinning" was developed for the making of these hybrid fibers. In spray-spinning, a chitosan solution was sprayed into a flowing sodium alginate solution and sheared into streamlines. The elongated streamlines subsequently transformed into alginate/chitosan PEC fibers. Average diameter of the fibers increased with the increasing of chitosan concentration used in spinning. The fibers showed a high water-absorbability of about 45 folds of water to their dry weight and retained their integrity after incubation in Minimum Essential Medium (MEM) for up to 30 days. In vitro co-culture experiments indicated that the fibers could support the three-dimensional growth of HepG2 cells and did not display any cyto-toxicity. Moreover, in vivo implanting experiments indicated that the connective tissue cells infiltrated into the implanted fibrous scaffolds in 3 weeks after surgery. These results demonstrated the potential applications of the as-spun fibers in regenerative medicine and tissue engineering. PMID:19756966

  19. The spray drying of acetazolamide as method to modify crystal properties and to improve compression behaviour.

    PubMed

    Di Martino, P; Scoppa, M; Joiris, E; Palmieri, G F; Andres, C; Pourcelot, Y; Martelli, S

    2001-02-01

    Acetazolamide shows a very poor compression ability and tablets must usually be produced through a wet granulation process. However, the possibility to obtain pure acetazolamide for direct compression could be interesting for industrial application. With the scope to obtain a material for direct compression, three different crystallisation methods were chosen, with respect to acetazolamide solvent solubility. (a) Acetazolamide was dissolved in an ammonia solution and then spray dried. It was possible to characterise the spherical particles as a mixture of two polymorphic forms, I and II by Powder X-ray diffraction study. (b) Pure form I was obtained by slowly cooling to room temperature a boiling water solution. (c) Pure form II, the marketed form, was obtained by neutralisation of an ammonia solution. Their compression behaviour was investigated firstly by a rotary press. Whilst pure polymorphic forms I and II could not be compressed, the spray dried particles showed very good compression properties. In fact, tablets were obtained only by spray dried particles, which show very good properties under compression and the absence of capping tendency. On the other hand, it was impossible to obtain tablets from polymorphic forms I and II, whatever compression pressures were used. In order to explain their densification mechanism, a single-punch tablet machine, equipped for the measurement of the upper punch displacement in the die, was used. From calculated Heckel's parameters, it was demonstrated that the spray dried material shows a greater particle rearrangement in the initial stage of compression due to its spherical habit and minor wrinkledness of particle surface. The crystalline structure due to the presence of polymorphic forms I and II concur to lowering the intrinsic elasticity of the material. This fact avoids the risk of the rupturing the interpaticulate bonds, which are formed during the compression, concurring to the consolidation of the tablet. PMID

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

    SciTech Connect

    Gaikwad, Rajendra S.; Bhande, Sambhaji S.; Mane, Rajaram S.; Pawar, Bhagwat N.; Gaikwad, Sanjay L.; Han, Sung-Hwan; Joo, Oh-Shim

    2012-12-15

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

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

    SciTech Connect

    Hong, Young Jun; Choi, Seung Ho; Sim, Chul Min; Lee, Jung-Kul; Kang, Yun Chan

    2012-12-15

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

  2. Electrochemical properties of yolk-shell-structured CuO-Fe(2)O(3) powders with various Cu/Fe molar ratios prepared by one-pot spray pyrolysis.

    PubMed

    Yang, Kwang Min; Hong, Young Jun; Kang, Yun Chan

    2013-12-01

    Several yolk-shell-structured CuO-Fe2 O3 powders with various Cu/Fe molar ratios have been successfully prepared under equivalent reaction conditions using a one-pot spray pyrolysis process. The Cu and Fe components are uniformly distributed throughout the powders, irrespective of composition. The Brunauer-Emmett-Teller surface areas of the yolk-shell CuO-Fe2 O3 systems increased from 5 to 16 m(2)  g(-1) if the Cu/Fe molar ratios are decreased from 3:1 to 1:3. The initial discharge and charge capacities of the yolk-shell CuO-Fe2 O3 system (Cu/Fe=1:2), showing maximum values at a constant current density of 1000 mA g(-1) , are 1436 and 1012 mA h g(-1) , respectively. After 130 cycles, the discharge capacities of the yolk-shell CuO-Fe2 O3 powders with Cu/Fe molar ratios of 1:3, 1:2, 1:1, 2:1, and 3:1 are 1159, 1151, 755, 655, and 651 mA h g(-1) , respectively. The discharge capacities of the yolk-shell and dense powder samples after 50 cycles, when subjected to a series of current density increases from 500 to 5000 mA g(-1) , are 735 and 495 mA h g(-1) , respectively. PMID:24106078

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

    NASA Technical Reports Server (NTRS)

    Paxson, Daniel E. (Inventor)

    2014-01-01

    An apparatus and method for 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 as 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 metal 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 tailpipe of said pulsejet and is expelled therefrom at high velocity and deposited on a target substrate.

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

    PubMed Central

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

    2013-01-01

    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

  5. Effect of antimicrobials applied on the surface of beef subprimals via an air-assisted electrostatic spraying system(ESS)or the Sprayed Lethality in Container(SLIC)method to control Shiga toxin-producing cells of Escherichia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We evaluated the efficacy of an air-assisted electrostatic spraying system (ESS) and/or the Sprayed Lethality in Container (SLIC®) method to deliver antimicrobials onto the surface of beef subprimals to reduce levels of Shiga toxin-producing cells of Escherichia coli (STEC). In brief, beef subprimal...

  6. Numerical Analysis of Cold Spray Particles Impacting Behavior by the Eulerian Method: A Review

    NASA Astrophysics Data System (ADS)

    Li, W. Y.; Yang, K.; Yin, S.; Guo, X. P.

    2016-08-01

    Numerical simulations have been widely used to study particles impacting behavior in cold spraying. Among the used simulation methods, the Eulerian frame becomes increasingly attractive for its absence of mesh distortion which happens in the Lagrangian frame. It has been proved that particle deformation behaviors upon impacting calculated by the Eulerian method are well comparable to the experimental observations. In this review article, the literature on modeling particle impacting by the Eulerian method was summarized. In the second part, the Eulerian method was detailedly introduced. In the third part, the particle/substrate impacting behavior, and its influencing factors, i.e., mesh resolution, particle impacting velocity, preheating (particle or/and substrate) and oxide film, were summarized. Additionally, the prediction of critical velocity and residual stresses by using the Eulerian method was also discussed in detail. Finally, the current issues, problems and prospects existing in the Eulerian simulations of particle impacting were explored.

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

    PubMed

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

    2012-09-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

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

  10. A novel method for preparing proton exchange membrane fuel cell electrodes by the ultrasonic-spray technique

    NASA Astrophysics Data System (ADS)

    Millington, Ben; Whipple, Vincent; Pollet, Bruno G.

    2011-10-01

    A novel ultrasonic-spray method for preparing gas diffusion electrodes (GDEs) for proton exchange membrane fuel cell (PEMFC) is described. Platinum (Pt) loaded on Nafion®-bonded GDEs were prepared by the ultrasonic-spray method on various commercial woven and non-woven gas diffusion layers (GDLs) at several Pt loadings in the range of 0.40-0.05 mg cm-2. The ultrasonic-sprayed GDEs were tested and compared to commercial and hand-painted GDEs. It was found that the GDEs prepared by the ultrasonic-spray method exhibited better performances compared to those prepared by the hand-painting technique, especially at low Pt loadings. GDEs fabricated by the ultrasonic-spray method with a platinum loading of 0.05 mg cm-2 exhibited a peak power rating of 10.9 W mg-1 compared to 9.8 W mg-1 for hand-painted GDEs. For all experiments using various GDLs, Sigracet SGL 10BC exhibited the best performance with a peak power of 0.695 W cm-2.

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

    SciTech Connect

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

    2012-10-12

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

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

    SciTech Connect

    Kerber, Pranita; Porter, Lisa M.; McCullough, Lynne A.; Kowalewski, Tomasz; Engelhard, Mark; Baer, Donald

    2012-11-15

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

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

    USGS Publications Warehouse

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

    2011-01-01

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

  14. Anisotropic Mechanical Properties of Plasma-Sprayed Thermal Barrier Coatings at High Temperature Determined by Ultrasonic Method

    NASA Astrophysics Data System (ADS)

    Wei, Qin; Zhu, Jianguo; Chen, Wei

    2016-02-01

    The mechanical properties of plasma-sprayed thermal barrier coatings (TBC) are of great scientific and technological significance for the design and fabrication of TBC systems. The ultrasonic method combined with a sing-around method for mechanical properties measurement of TBC is deduced and the elastic modulus can be determined in the spray, or longitudinal, direction, and the transverse direction. Tested specimens of plasma-sprayed TBC are detached from the substrate and treated with thermal exposure at 1400 °C. The elastic moduli along the longitudinal and transverse directions of the TBCs are measured by different types of ultrasonic waves combined with a sing-around method, while the Poisson's ratio is also obtained simultaneously. The experimental results indicate that the magnitude of longitudinal elastic modulus is larger than that of the transverse one, and thus the plasma-sprayed TBC has an anisotropic mechanical property. Moreover, the elastic moduli along both longitudinal and transverse directions change with high-temperature exposure time, which consists of a rapid increasing stage followed by a slow decreasing stage. In addition, the magnitude of Poisson's ratio increases slightly from 0.05 to 0.2 with the high-temperature exposure time. Generally, the microstructures in the plasma-sprayed coatings and their evolution in a high-temperature environment are the main causes of the varying anisotropic mechanical properties.

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

    NASA Astrophysics Data System (ADS)

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

    2010-10-01

    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, 2κ 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

  16. A composition joint PDF method for the modeling of spray flames

    NASA Technical Reports Server (NTRS)

    Raju, M. S.

    1995-01-01

    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.

  17. Thermal sprayed composite melt containment tubular component and method of making same

    DOEpatents

    Besser, Matthew F.; Terpstra, Robert L.; Sordelet, Daniel J.; Anderson, Iver E.

    2002-03-19

    A tubular thermal sprayed melt containment component for transient containment of molten metal or alloy wherein the tubular member includes a thermal sprayed inner melt-contacting layer for contacting molten metal or alloy to be processed, a thermal sprayed heat-generating layer deposited on the inner layer, and an optional thermal sprayed outer thermal insulating layer. The thermal sprayed heat-generating layer is inductively heated as a susceptor of an induction field or electrical resistively heated by passing electrical current therethrough. The tubular thermal sprayed melt containment component can comprise an elongated melt pour tube of a gas atomization apparatus where the melt pour tube supplies molten material from a crucible to an underlying melt atomization nozzle.

  18. Comparison of sampling methods for monomer and polyisocyanates of 1,6-hexamethylene diisocyanate during spray finishing operations.

    PubMed

    England, E; Key-Schwartz, R; Lesage, J; Carlton, G; Streicher, R; Song, R

    2000-06-01

    A comparison study of isocyanate sampling methods for 1,6-hexamethylene diisocyanate (HDI) monomer and HDI-based polyisocyanates was conducted in spray painting environments. This study compared the performance of the Iso-chek sampler against existing and proposed National Institute of Occupational Safety and Health (NIOSH) and Occupational Safety and Health Administration (OSHA) monitoring methods for HDI-based isocyanates. Six methods for monitoring HDI monomer and polyisocyanate levels were compared. Fifty-eight sampling sets were collected during spray painting of aircraft and aircraft parts at four U.S. Air Force bases. Impinger and cassette samplers were mounted side-by-side on a mannequin located in paint overspray areas. For HDI monomer sampling results, there were no significant differences between NIOSH 5521, NIOSH 5522, OSHA 42, MAP (the proposed NIOSH method), and the Iso-Chek. For HDI-based polyisocyanates, NIOSH 5522, NIOSH 5521, Iso-Chek, and the Total Aerosol Mass Method (TAMM) were significantly different from one another. There was no significant difference between MAP and the NIOSH 5522 polyisocyanate sampling results. This study suggests the Iso-Chek and MAP sampling methods compare favorably with established methods for monitoring in HDI spray painting environments and the Total Aerosol Mass Method provides a reasonable upper boundary for estimating HDI polyisocyanate concentrations. The results also reemphasize aerosol sampling physics and sampler geometries must be carefully considered and appropriate samplers used when measuring exposures in spray paint environments where particulates are of the inhalable size. PMID:10853287

  19. Effects of fuel cetane number on the structure of diesel spray combustion: An accelerated Eulerian stochastic fields method

    NASA Astrophysics Data System (ADS)

    Jangi, Mehdi; Lucchini, Tommaso; Gong, Cheng; Bai, Xue-Song

    2015-09-01

    An Eulerian stochastic fields (ESF) method accelerated with the chemistry coordinate mapping (CCM) approach for modelling spray combustion is formulated, and applied to model diesel combustion in a constant volume vessel. In ESF-CCM, the thermodynamic states of the discretised stochastic fields are mapped into a low-dimensional phase space. Integration of the chemical stiff ODEs is performed in the phase space and the results are mapped back to the physical domain. After validating the ESF-CCM, the method is used to investigate the effects of fuel cetane number on the structure of diesel spray combustion. It is shown that, depending of the fuel cetane number, liftoff length is varied, which can lead to a change in combustion mode from classical diesel spray combustion to fuel-lean premixed burned combustion. Spray combustion with a shorter liftoff length exhibits the characteristics of the classical conceptual diesel combustion model proposed by Dec in 1997 (http://dx.doi.org/10.4271/970873), whereas in a case with a lower cetane number the liftoff length is much larger and the spray combustion probably occurs in a fuel-lean-premixed mode of combustion. Nevertheless, the transport budget at the liftoff location shows that stabilisation at all cetane numbers is governed primarily by the auto-ignition process.

  20. Influence of Starting Powders on Hydroxyapatite Coatings Fabricated by Room Temperature Spraying Method.

    PubMed

    Seo, Dong Seok; Lee, Jong Kook; Hwang, Kyu Hong; Hahn, Byung Dong; Yoon, Seog Young

    2015-08-01

    Three types of raw materials were used for the fabrication of hydroxyapatite coatings by using the room temperature spraying method and their influence on the microstructure and in vitro characteristics were investigated. Starting hydroxyapatite powders for coatings on titanium substrate were prepared by a heat treatment at 1100 °C for 2 h of bovine bone, bone ash, and commercial hydroxyapatite powders. The phase compositions and Ca/P ratios of the three hydroxyapatite coatings were similar to those of the raw materials without decomposition or formation of a new phase. All hydroxyapatite coatings showed a honeycomb structure, but their surface microstructures revealed different features in regards to surface morphology and roughness, based on the staring materials. All coatings consisted of nano-sized grains and had dense microstructure. Inferred from in vitro experiments in pure water, all coatings have a good dissolution-resistance and biostability in water.

  1. Characterization of CuZnO Diodes Prepared by Ultrasonic Spray Method

    NASA Astrophysics Data System (ADS)

    Chen, Lung-Chien; Hsieh, Cheng-An

    2015-12-01

    Zinc oxide (ZnO) nanostructures have attracted considerable research interest owing to their useful properties. Recently, doping with Cu atoms has been increasingly attracting attention because of its potential applications in semiconductor devices. In this study, CZO films were prepared on glass substrates by an ultrasonic spray method using zinc acetate, copper acetate, and aqueous ammonium acetate as precursors. The electrical and optical properties of the prepared CZO films and the ZnO/CZO diodes are discussed. This study comprises two parts. First, CZO films with Cu weight percentages from 10 wt.% to 30 wt.%. The electrical and optical properties of the CZO films were measured and compared. Second, a ZnO/CZO diode was fabricated on an ITO substrate. The I- V curve of the device was obtained with or without exposure to a magnetic field.

  2. Influence of Starting Powders on Hydroxyapatite Coatings Fabricated by Room Temperature Spraying Method.

    PubMed

    Seo, Dong Seok; Lee, Jong Kook; Hwang, Kyu Hong; Hahn, Byung Dong; Yoon, Seog Young

    2015-08-01

    Three types of raw materials were used for the fabrication of hydroxyapatite coatings by using the room temperature spraying method and their influence on the microstructure and in vitro characteristics were investigated. Starting hydroxyapatite powders for coatings on titanium substrate were prepared by a heat treatment at 1100 °C for 2 h of bovine bone, bone ash, and commercial hydroxyapatite powders. The phase compositions and Ca/P ratios of the three hydroxyapatite coatings were similar to those of the raw materials without decomposition or formation of a new phase. All hydroxyapatite coatings showed a honeycomb structure, but their surface microstructures revealed different features in regards to surface morphology and roughness, based on the staring materials. All coatings consisted of nano-sized grains and had dense microstructure. Inferred from in vitro experiments in pure water, all coatings have a good dissolution-resistance and biostability in water. PMID:26369193

  3. An approximate method for analyzing transient condensation on spray in HYLIFE-II

    SciTech Connect

    Bai, R.Y.; Schrock, V.E. . Dept. of Nuclear Engineering)

    1990-01-01

    The HYLIFE-II conceptual design calls for analysis of highly transient condensation on droplets to achieve a rapidly decaying pressure field. Drops exposed to the required transient vapor pressure field are first heated by condensation but later begin to reevaporate after the vapor temperature falls below the drop surface temperature. An approximate method of analysis has been developed based on the assumption that the thermal resistance is concentrated in the liquid. The time dependent boundary condition is treated via the Duhamel integral for the pure conduction model. The resulting Nusselt number is enhanced to account for convection within the drop and then used to predict the drop mean temperature history. Many histories are considered to determine the spray rate necessary to achieve the required complete condensation.

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

    NASA Technical Reports Server (NTRS)

    Paxson, Daniel E. (Inventor)

    2010-01-01

    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.

  5. [Optimization of spraying dry technology of Biqiu ranules ethanol extract by Box-Behnken response surface method].

    PubMed

    Zhang, Yan-jun; Liu, Li-li; Hu, Jun-hua; Wu, Yun; Chao, En-xiang; Xiao, Wei

    2015-09-01

    With inlet temperature, specific gravity, feeding speed as independent variables, the comprehensive evaluating indexes of content of schisandrin and arctiin as dependent variable, the experimental data were fitted to a second order polynomial equation. Based on establishing the mathematical relationship between the comprehensive evaluating indexes and respective variables, Box-Benhnken central composite test and response surface analysis method was employed to optimize the spray drying technology of Biqiu granules ethanol extract. The optimal drying parameter was as follows: the inlet temperature was 175 degrees C, the specific gravity was 1.10, feeding speed was 32 r x min(-1). Under these conditions, the comprehensive evaluating indexes of spraying dry processes was 92.68, which was close to the model prediction. The spraying dry technology of Biqiu granules ethanol extract optimized by response surface methodology was accurate and feasible, which provided theoretical experiment basis for the industrialization production. PMID:26983204

  6. Alternative methods for herbicide spray drift detection in corn and cotton

    NASA Astrophysics Data System (ADS)

    Buehring, Nathan Wade

    The acceptance of herbicide-resistant crops and the subsequent increase in glyphosate use throughout the growing season has led to increased problems with herbicide drift in corn and cotton. Potential yield losses due to herbicide spray drift cannot always be accurately assessed using visual ratings or by measuring reductions in plant height. This research was conducted to determine if other methods, such as biochemical assays or remote sensing, could be used to assess potential yield reductions and visual injury associated with herbicide drift. Other objectives included using hyperspectral and multispectral remote sensing for herbicide drift detection in corn and cotton. Classification accuracies were highest 14 DAA when distinguishing untreated from treated corn. When the data were classified by herbicides, overall accuracies of ≥74% resulted 14 and 28 DAA. Classifications based on yield reduction also resulted in highest overall classification accuracies 14 and 28 DAA, ranging from 69 to 70%. Within the glufosinate-treated corn, overall accuracies for classifying percent yield reductions was 85% at 3 DAA and decreased to 68% at 28 DAA. Overall classification accuracies for determining percent yield reductions with glyphosate were higher 14 and 28 DAA. With pyrithiobac, overall accuracies for determining percent yield reductions ranged from 73 to 82% across all evaluations. Of the nine vegetative indices tested to classify the data, Anthocyanin Reflective Index (ARI) and Chlorophyll Fluorescence Ratio of reflectance at 735 nm/700 nm (CF 735) were the most important for classifying, assessing, and detecting herbicide spray drift in corn. Multispectral aerial imagery was also used to identify cotton affected by a simulated bromoxynil drift event. Multispectral aerial imagery collected 9 DAA in 2002 resulted in better classification accuracies for identifying bromoxynil rate, percent visual injury, and percent yield reduction than imagery collected 21 DAA in 2001

  7. Laser processing of high-chromium nickel-chromium coatings deposited by various thermal spraying methods

    SciTech Connect

    Longa, Y.; Takemoto, M. . Coll. of Science and Engineering)

    1994-11-01

    High-chromium Ni-Cr coatings were deposited by thermal spraying in air and in an argon gas atmosphere. Coatings sprayed in Ar gas were free of pores and defects and of the same chemical composition as the spraying material. Following thermal spraying for each coating, laser glazing or laser gas alloying was applied to provide a protective chromium oxide film, produced by the intermediate oxidation process on top of the coatings. Five types of coatings were treated: (1) arc and (2) flame spraying in Ar, (3) arc and (4) flame spraying in air, and (5) low-pressure plasma spraying (LPPS). Oxide formation mechanisms during laser processing were studied, and the oxidation and hot-corrosion resistance of the coatings in the presence of a sulfate-vanadate fused salt at 900 C in air were examined. High-chromium Ni-Cr coatings deposited by thermal spraying, and they are used mostly to prevent ash attack of boilers and furnace tubes in power plants and oil refineries.

  8. Measurement of spray combustion processes

    NASA Technical Reports Server (NTRS)

    Peters, C. E.; Arman, E. F.; Hornkohl, J. O.; Farmer, W. M.

    1984-01-01

    A free jet configuration was chosen for measuring noncombusting spray fields and hydrocarbon-air spray flames in an effort to develop computational models of the dynamic interaction between droplets and the gas phase and to verify and refine numerical models of the entire spray combustion process. The development of a spray combustion facility is described including techniques for laser measurements in spray combustion environments and methods for data acquisition, processing, displaying, and interpretation.

  9. Comparative study on combined co-pyrolysis/gasification of walnut shell and bituminous coal by conventional and congruent-mass thermogravimetric analysis (TGA) methods.

    PubMed

    Zhang, Yan; Fan, Di; Zheng, Yan

    2016-01-01

    Combined co-pyrolysis/gasification of bituminous coal (BC) and walnut shell (WS) are comparatively studied with both conventional and congruent-mass thermogravimertric analysis (TGA) methods. The results indicate that BC and WS exhibit additivity in the co-pyrolysis step. However, the gasification reactivity of chars in subsequent gasification step exhibits remarkable sample-mass dependence, which causes the illusions in synergy and inhibition effects when conventional TGA tests are conducted. A congruent-mass TGA method has been developed to overcome the limitations of the conventional TGA mode. One of the advantages of this method is that it can reduce to a minimum the effect of sample mass on reactivity. Thus, the degree of synergy or inhibition can be directly estimated from the deviation of the experimental TG curves between the two separated and blended samples. We recommend this method in studying the co-processing behavior between coal and biomass.

  10. Comparative study on combined co-pyrolysis/gasification of walnut shell and bituminous coal by conventional and congruent-mass thermogravimetric analysis (TGA) methods.

    PubMed

    Zhang, Yan; Fan, Di; Zheng, Yan

    2016-01-01

    Combined co-pyrolysis/gasification of bituminous coal (BC) and walnut shell (WS) are comparatively studied with both conventional and congruent-mass thermogravimertric analysis (TGA) methods. The results indicate that BC and WS exhibit additivity in the co-pyrolysis step. However, the gasification reactivity of chars in subsequent gasification step exhibits remarkable sample-mass dependence, which causes the illusions in synergy and inhibition effects when conventional TGA tests are conducted. A congruent-mass TGA method has been developed to overcome the limitations of the conventional TGA mode. One of the advantages of this method is that it can reduce to a minimum the effect of sample mass on reactivity. Thus, the degree of synergy or inhibition can be directly estimated from the deviation of the experimental TG curves between the two separated and blended samples. We recommend this method in studying the co-processing behavior between coal and biomass. PMID:26306847

  11. Paper spray mass spectrometry-based method for analysis of droplets in a gravity-driven microfluidic chip.

    PubMed

    Zhang, Yandong; Li, Haifang; Ma, Yuan; Lin, Jin-Ming

    2014-03-01

    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.

  12. Standardization of chemical analytical techniques for pyrolysis bio-oil: history, challenges, and current status of methods

    DOE PAGESBeta

    Ferrell, Jack R.; Olarte, Mariefel V.; Christensen, Earl D.; Padmaperuma, Asanga B.; Connatser, Raynella M.; Stankovikj, Filip; Meier, Dietrich; Paasikallio, Ville

    2016-07-05

    Here, we discuss the standardization of analytical techniques for pyrolysis bio-oils, including the current status of methods, and our opinions on future directions. First, the history of past standardization efforts is summarized, and both successful and unsuccessful validation of analytical techniques highlighted. The majority of analytical standardization studies to-date has tested only physical characterization techniques. In this paper, we present results from an international round robin on the validation of chemical characterization techniques for bio-oils. Techniques tested included acid number, carbonyl titrations using two different methods (one at room temperature and one at 80 °C), 31P NMR for determination ofmore » hydroxyl groups, and a quantitative gas chromatography–mass spectrometry (GC-MS) method. Both carbonyl titration and acid number methods have yielded acceptable inter-laboratory variabilities. 31P NMR produced acceptable results for aliphatic and phenolic hydroxyl groups, but not for carboxylic hydroxyl groups. As shown in previous round robins, GC-MS results were more variable. Reliable chemical characterization of bio-oils will enable upgrading research and allow for detailed comparisons of bio-oils produced at different facilities. Reliable analytics are also needed to enable an emerging bioenergy industry, as processing facilities often have different analytical needs and capabilities than research facilities. We feel that correlations in reliable characterizations of bio-oils will help strike a balance between research and industry, and will ultimately help to -determine metrics for bio-oil quality. Lastly, the standardization of additional analytical methods is needed, particularly for upgraded bio-oils.« less

  13. Lake spray aerosol generation: a method for producing representative particles from freshwater wave breaking

    NASA Astrophysics Data System (ADS)

    May, Nathaniel W.; Axson, Jessica L.; Watson, Alexa; Pratt, Kerri A.; Ault, Andrew P.

    2016-09-01

    Wave-breaking action in bodies of freshwater produces atmospheric aerosols via a similar mechanism to sea spray aerosol (SSA) from seawater. The term lake spray aerosol (LSA) is proposed to describe particles formed by this mechanism, which have been observed over the Laurentian Great Lakes. Though LSA has been identified from size distribution measurements during a single measurement campaign, no measurements of LSA composition or relationship to bubble-bursting dynamics have been conducted. An LSA generator utilizing a plunging jet, similar to many SSA generators, was constructed for the generation of aerosol from freshwater samples and model salt solutions. To evaluate this new generator, bubble and aerosol number size distributions were measured for salt solutions representative of freshwater (CaCO3) and seawater (NaCl) at concentrations ranging from that of freshwater to seawater (0.05-35 g kg-1), synthetic seawater (inorganic), synthetic freshwater (inorganic), and a freshwater sample from Lake Michigan. Following validation of the bubble and aerosol size distributions using synthetic seawater, a range of salt concentrations were investigated. The systematic studies of the model salts, synthetic freshwater, and Lake Michigan sample indicate that LSA is characterized by a larger number size distribution mode diameter of 300 nm (lognormal), compared to seawater at 110 nm. Decreasing salt concentrations from seawater to freshwater led to greater bubble coalescence and formation of larger bubbles, which generated larger particles and lower aerosol number concentrations. This resulted in a bimodal number size distribution with a primary mode (180 ± 20 nm) larger than that of SSA, as well as a secondary mode (46 ± 6 nm) smaller than that of SSA. This new method for studying LSA under isolated conditions is needed as models, at present, utilize SSA parameterizations for freshwater systems, which do not accurately predict the different size distributions observed

  14. A Novel and Simple Method for the Synthesis of β-SiC/SiO2 Coaxial Nanocables in a Large Area: Polycarbosilane Pyrolysis.

    PubMed

    Song, Guanying; Li, Zhenjiang; Sun, Shasha; Meng, Alan; Ma, FengLin

    2016-03-01

    In the present work, β-SiC/SiO2 coaxial nanocables are synthesized in a large area via direct pyrolysis of polymeric precursor method, in which, polycarbosilane acts the single raw material. The morphology, chemical composition and detailed microstructure of the nanocables are characterized. The core of nanocables are single crystalline β-SiC nanowires with diameter of 30 - 60 nm grown along [111] direction. The uniform coating layer is amorphous SiO2 with thickness of 15 nm. Based on the pyrolysis process of polycarbosilane, the Vapor-Liquid-Solid growth mechanism is discussed. Furthermore, field emission measurements show the turn-on field and the threshold field are 3.2 V/μm and 6.5 V/μm, respectively. This study shows that β-SiC/SiO2 coaxial nanocables are promising for field emission display device and other vacuum electronic devices. PMID:27455721

  15. Pyrolysis products of PCBs.

    PubMed Central

    Paasivirta, J; Herzschuh, R; Humppi, T; Kantolahti, E; Knuutinen, J; Lahtiperä, M; Laitinen, R; Salovaara, J; Tarhanen, J; Virkki, L

    1985-01-01

    Model compound studies which were previously done for impurities and environmental residues of chlorophenols and for wastes of chlorination processes were extended to the impurities and pyrolysis products of polychlorinated biphenyls (PCBs). Model compounds were commercial products or synthesized and their structures proven by spectroscopic methods. These models were used as analytical reference substances in GC/ECD and GC/MS studies of the pyrolyzed PCB samples. In addition to previously known neutral components like polychlorinated dibenzofurans (PCDFs), chlorophenolic substances, especially polychlorophenols (PCPs) and polychlorinated biphenylols (PCB-OHs) were observed as major pyrolysis products of PCBs. Capacitor fires are suggested to produce in many cases chlorophenols which are major toxic hazards to people. PMID:3928353

  16. Characterization of scandia doped pressed cathode fabricated by spray drying method

    NASA Astrophysics Data System (ADS)

    Cui, Yuntao; Wang, Jinshu; Liu, Wei; Wang, Yiman; Zhou, Meiling

    2011-10-01

    Scandia doped pressed cathode was prepared by a new method of spray drying combined with two-step hydrogen reduction process. The Sc 2O 3 and barium-calcium aluminate co-doped powders have sub-micrometer size in the range of 0.1-1 μm and scandium oxide and barium-calcium aluminate are distributed evenly in the powders. The cathodes sintered by powder metallurgy at 1600 °C b have a smooth surface and sub-micrometer grain structure with homogeneous distribution of scandium, barium, calcium and aluminum which are dispersed over and among the tungsten grains. This cathode has good emission, e.g., the current density of this cathode reaches 31.50 A/cm 2 at 850 °C b. After proper activation, the cathode surface is covered by a Ba-Sc-O active substances layer with a preferable atomic ratio, leading to its good emission property. The evaporation activation energy of SDP cathode with 4.58 eV is the highest among the Ba-W, M-type and SDP cathodes, and the average evaporation velocity vt of SDP cathode with 1.28 × 10 -8 g cm -2 s -1 at 1150 °C b is the lowest one.

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

    DOEpatents

    Lenling, William J.; Henfling, Joseph A.; Smith, Mark F.

    1993-06-08

    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.

  18. Fluorine doped-tin oxide prepared using spray method for dye sensitized solar cell application

    NASA Astrophysics Data System (ADS)

    Widiyandari, Hendri; Purwanto, Agus; Diharjo, Kuncoro; Suyitno, Hidayanto, Eko

    2013-09-01

    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 Ω/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 (λ=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 Ω/sq, respectively. It is shown that the optimum DSSC efficiency was made from FTO with sheet resistance 12.1 Ω/sq.

  19. Through-thickness residual stress evaluations for several industrial thermal spray coatings using a modified layer-removal method

    NASA Astrophysics Data System (ADS)

    Greving, D. J.; Rybicki, E. F.; Shadley, J. R.

    1994-12-01

    Residual stresses are inherent in thermal spray coatings because the application process involves large temperature gradients in materials with different mechanical properties. In many cases, failure analysis of thermal spray coatings has indicated that residual stresses contribute to reduced service life. An estab-lished method for experimentally evaluating residual stresses involves monitoring deformations in a part as layers of material are removed. Although the method offers several advantages, applications are lim-ited to a single isotropic material and do not include coated materials. This paper describes a modified layer-removal method for evaluating through-thickness residual stress distributions in coated materials. The modification is validated by comparisons with three-dimensional finite-element analysis results. The modified layer-removal method was applied to determine through-thickness residual stress distributions for six industrial thermal spray coatings: stainless steel, aluminum, Ni-5A1, two tungsten carbides, and a ceramic thermal barrier coating. The modified method requires only ordinary resistance strain-gage measuring equipment and can be relatively insensitive to uncertainties in the mechanical properties of the coating material.

  20. Miniature spray-painting booth

    NASA Technical Reports Server (NTRS)

    Fee, K. W.

    1970-01-01

    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.

  1. Method and closing pores in a thermally sprayed doped lanthanum chromite interconnection layer

    DOEpatents

    Singh, Prabhakar; Ruka, Roswell J.

    1995-01-01

    A dense, substantially gas-tight electrically conductive interconnection layer is formed on an air electrode structure of an electrochemical cell by (A) providing an air electrode surface; (B) forming on a selected portion of the electrode surface, a layer of doped LaCrO.sub.3 particles doped with an element or elements selected from Ca, Sr, Ba, Mg, Co, Ni, Al and mixtures thereof by thermal spraying doped LaCrO.sub.3 particles, either by plasma arc spraying or flame spraying; (C) depositing a mixture of CaO and Cr.sub.2 O.sub.3 on the surface of the thermally sprayed layer; and (D) heating the doped LaCrO.sub.3 layer coated with CaO and Cr.sub.2 O.sub.3 surface deposit at from about 1000.degree. C. to 1200.degree. C. to substantially close the pores, at least at a surface, of the thermally sprayed doped LaCrO.sub.3 layer. The result is a dense, substantially gas-tight, highly doped, electrically conductive interconnection material bonded to the electrode surface. A solid electrolyte layer can be applied to the nonselected portion of the air electrode. A fuel electrode can be applied to the solid electrolyte, to form an electrochemical cell, for example for generation of electrical power.

  2. Method and closing pores in a thermally sprayed doped lanthanum chromite interconnection layer

    DOEpatents

    Singh, P.; Ruka, R.J.

    1995-02-14

    A dense, substantially gas-tight electrically conductive interconnection layer is formed on an air electrode structure of an electrochemical cell by (A) providing an air electrode surface; (B) forming on a selected portion of the electrode surface, a layer of doped LaCrO{sub 3} particles doped with an element or elements selected from Ca, Sr, Ba, Mg, Co, Ni, Al and mixtures thereof by thermal spraying doped LaCrO{sub 3} particles, either by plasma arc spraying or flame spraying; (C) depositing a mixture of CaO and Cr{sub 2}O{sub 3} on the surface of the thermally sprayed layer; and (D) heating the doped LaCrO{sub 3} layer coated with CaO and Cr{sub 2}O{sub 3} surface deposit at from about 1,000 C to 1,200 C to substantially close the pores, at least at a surface, of the thermally sprayed doped LaCrO{sub 3} layer. The result is a dense, substantially gas-tight, highly doped, electrically conductive interconnection material bonded to the electrode surface. A solid electrolyte layer can be applied to the nonselected portion of the air electrode. A fuel electrode can be applied to the solid electrolyte, to form an electrochemical cell, for example for generation of electrical power. 5 figs.

  3. A pyrolysis/gas chromatographic method for the determination of hydrogen in solid samples

    NASA Technical Reports Server (NTRS)

    Carr, R. H.; Bustin, R.; Gibson, E. K.

    1987-01-01

    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.

  4. Method for Thermal Spraying of Coatings Using Resonant-Pulsed Combustion

    NASA Technical Reports Server (NTRS)

    Paxson, Daniel E.

    2008-01-01

    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.

  5. Non-Destructive Evaluation of Thermal Spray Coating Interface Quality By Eddy Current Method

    SciTech Connect

    B. Mi; G. Zhao; R. Bayles

    2006-08-10

    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.

  6. Nondestructive Evaluation of Thermal Spray Coating Interface Quality by Eddy Current Method

    NASA Astrophysics Data System (ADS)

    Mi, Bao; Zhao, Xiaoliang (George); Bayles, Robert

    2007-03-01

    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.

  7. Microencapsulation of Lactobacillus plantarum (mtcc 5422) by spray-freeze-drying method and evaluation of survival in simulated gastrointestinal conditions.

    PubMed

    Dolly, Priyanka; Anishaparvin, A; Joseph, G S; Anandharamakrishnan, C

    2011-01-01

    Spray-drying (SD) and freeze-drying (FD) are widely used methods for microencapsulation of heat-sensitive materials like probiotics for long-term preservation and transport. Spray-freeze-drying (SFD) is relatively a new technique that involves spraying a solution into a cold medium and removal of solvent (water) by conventional vacuum FD method. In this study, the SFD microencapsulated Lactobacillus plantarum powder (1:1 and 1:1.5 core-to-wall ratios of whey protein) is compared with the microencapsulated powders produced by FD and SD methods. The SFD and FD processed microencapsulated powder show 20% higher cell viability than the SD samples. In simulated gastrointestinal conditions, the SFD and FD cells show up to 4 h better tolerance than SD samples and unencapsulated cells in acidic and pepsin condition. The morphology of SFD samples shows particles almost in spherical shape with numerous fine pores, which in turn results in good rehydration behaviour of the powdered product.

  8. Toxicity of pyrolysis gases from polyether sulfone

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Olcomendy, E. M.

    1979-01-01

    A sample of polyether sulfone was evaluated for toxicity of pyrolysis gases, using the toxicity screening test method developed at the University of San Francisco. Animal response times were relatively short at pyrolysis temperatures of 600 to 800 C, with death occurring within 6 min. The principal toxicant appeared to be a compound other than carbon monoxide.

  9. Toxicity of pyrolysis gases from polyoxymethylene

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Schneider, J. E.; Brauer, D. P.

    1979-01-01

    A sample of polyoxymethylene was evaluated for toxicity of pyrolysis gases, using the toxicity screening test method developed at the University of San Francisco. Under several test conditions, this material gave shorter times to death than many other synthetic polymers. Carbon monoxide appeared to be the principal toxicant in the pyrolysis gases.

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

    NASA Astrophysics Data System (ADS)

    Callaghan, Adrian H.

    2013-09-01

    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, τdecay. A reevaluation of the DWM suggests that the whitecap timescale should account for the total whitecap lifetime (τwcap), which consists of both the formation timescale (τform) and the decay timescale (timescale definitions are given in the text). Here values of τform 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 τdecay to form 552 whitecap timescales. For the majority of whitecaps, τform makes up about 20-25% of τwcap, but this can be as large as 70% depending on the value of τdecay. Furthermore, an area-weighted mean whitecap timescale for use in the DWM (τDWM) 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.

  11. Antistatic sprays

    NASA Technical Reports Server (NTRS)

    Ming, James E.

    1989-01-01

    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.

  12. Evaluation of the Microcentrifuge Dissolution Method as a Tool for Spray-Dried Dispersion.

    PubMed

    Wu, Benjamin; Li, Jinjiang; Wang, Yahong

    2016-03-01

    Although using spray-dried dispersions (SDDs) to improve the bioavailability of poorly water-soluble compounds has become a common practice in supporting the early phases of clinical studies, their performance evaluation, whether in solid dosage forms or alone, still presents significant challenges. A microcentrifuge dissolution method has been reported to quickly assess the dissolution performance of SDDs. While the microcentrifuge dissolution method has been used in the SDD community, there is still a need to understand the mechanisms about the molecular species present in supernatant after centrifugation, the molecular nature of active pharmaceutical ingredients (APIs), as well as the impact of experimental conditions. In this paper, we aim to assess the effect of API and polymer properties on the dissolution behavior of SDDs along with centrifuging parameters, and for this, two poorly water-soluble compounds (indomethacin and ketoconazole) and two commonly used polymers in the pharmaceutical industry (PVP and HPMC-AS) were chosen to prepare SDDs. A typical microcentrifuge dissolution procedure as reported in the publication (Curatolo et al., Pharm Res 26:1419-1431, 2009) was followed. In addition, after separation of the supernatant from precipitation, some of the samples were filtered through filters of various sizes to investigate the particulate nature (particle size) of the supernatant. Furthermore, the centrifuge speed was varied to study sedimentation of API, SDD, or polymer particles. The results indicated that for the SDDs of four drug-polymer pairs, microcentrifuge dissolution exhibited varied behaviors, depending on the polymer and the drug used. The SDDs of indomethacin with either PVP or HPMC-AS showed a reproducible dissolution with minimum variability even after filtration and subjecting to varied centrifugation speed, suggesting that the supernatant behaved solution-like. However, ketoconazole-PVP and ketoconazole-HPMC-AS SDDs displayed a

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

    PubMed

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

    2010-12-01

    To control the release rate and mask the bitter taste, cetirizine dihydrochloride (CedH) was entrapped within chitosan nanoparticles (CS-NPs) using an ionotropic gelation process, followed by microencapsulation to produce CS matrix microparticles using a spray-drying method. The aqueous colloidal CS-NPs dispersions with a drug encapsulation efficiency (EE) of <15%, were then spray dried to produce a powdered nanoparticles-in-microparticles system with an EE of >70%. The resultant spherical CS microparticles had a smooth surface, were free of organic solvent residue and showed a diameter range of 0.5~5 μm. The in vitro drug release properties of CedH encapsulated microparticles showed an initial burst effect during the first 2 h. Drug release from the matrix CS microparticles could be retarded by the crosslinking agent pentasodium tripolyphosphate or the wall material. The technique of 'ionotropic gelation' combined with 'spray-drying' could be applicable for preparation of CS nanoparticlesin-microparticles drug delivery systems. CS-NPs based microparticles might provide a potential micro-carrier for oral administration of the freely water-soluble drug--CedH.

  14. Kinetic investigation of wood pyrolysis

    SciTech Connect

    Thurner, F.; Mann, U.; Beck, S. R.

    1980-06-01

    The objective of this investigation was to determine the kinetics of the primary reactions of wood pyrolysis. A new experimental method was developed which enabled us to measure the rate of gas, tar, and char production while taking into account the temperature variations during the wood heating up. The experimental method developed did not require any sophisticated instruments. It facilitated the collection of gas, tar and residue (unreacted wood and char) as well as accurate measurement of the temperature inside the wood sample. Expressions relating the kinetic parameters to the measured variables were derived. The pyrolysis kinetics was investigated in the range of 300 to 400/sup 0/C at atmospheric pressure and under nitrogen atmosphere. Reaction temperature and mass fractions of gas, tar, and residue were measured as a function of time. Assuming first-order reactions, the kinetic parameters were determined using differential method. The measured activation energies of wood pyrolysis to gas, tar, and char were 88.6, 112.7, and 106.5 kJ/mole, respectively. These kinetic data were then used to predict the yield of the various pyrolysis products. It was found that the best prediction was obtained when an integral-mean temperature obtained from the temperature-time curve was used as reaction temperature. The pyrolysis products were analyzed to investigate the influence of the pyrolysis conditions on the composition. The gas consisted mainly of carbon dioxide, carbon monoxide, oxygen, and C/sub 3//sup +/-compounds. The gas composition depended on reaction time as well as reactor temperature. The tar analysis indicated that the tar consisted of about seven compounds. Its major compound was believed to be levoglucosan. Elemental analysis for the char showed that the carbon content increased with increasing temperature.

  15. Method for thermally spraying crack-free mullite coatings on ceramic-based substrates

    NASA Technical Reports Server (NTRS)

    Spitsberg, Irene T. (Inventor); Wang, Hongyu (Inventor); Heidorn, Raymond W. (Inventor)

    2001-01-01

    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.

  16. Method for thermally spraying crack-free mullite coatings on ceramic-based substrates

    NASA Technical Reports Server (NTRS)

    Spitsberg, Irene T. (Inventor); Wang, Hongyu (Inventor); Heidorn, Raymond W. (Inventor)

    2000-01-01

    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.

  17. Evaluation of phosphorus adsorption capacity of sesame straw biochar on aqueous solution: influence of activation methods and pyrolysis temperatures.

    PubMed

    Park, J H; Ok, Y S; Kim, S H; Cho, J S; Heo, J S; Delaune, R D; Seo, D C

    2015-12-01

    The phosphorus (P) adsorption characteristic of sesame straw biochar prepared with different activation agents and pyrolysis temperatures was evaluated. Between 0.109 and 0.300 mg L(-1) in the form of inorganic phosphate was released from raw sesame straw biochar in the first 1 h. The release of phosphate was significantly enhanced from 62.6 to 168.2 mg g(-1) as the pyrolysis temperature increased. Therefore, sesame straw biochar cannot be used as an adsorbent for P removal without change in the physicochemical characteristics. To increase the P adsorption of biochar in aqueous solution, various activation agents and pyrolysis temperatures were applied. The amount of P adsorbed from aqueous solution by biochar activated using different activation agents appeared in the order ZnCl2 (9.675 mg g(-1)) > MgO (8.669 mg g(-1)) ⋙ 0.1N-HCl > 0.1N-H2SO4 > K2SO4 ≥ KOH ≥ 0.1N-H3PO4, showing ZnCl2 to be the optimum activation agent. Higher P was adsorbed by the biochar activated using ZnCl2 under different pyrolysis temperatures in the order 600 °C > 500 °C > 400 °C > 300 °C. Finally, the amount of adsorbed P by activated biochar at different ratios of biochar to ZnCl2 appeared in the order 1:3 ≒ 1:1 > 3:1. As a result, the optimum ratio of biochar to ZnCl2 and pyrolysis temperature were found to be 1:1 and 600 °C for P adsorption, respectively. The maximum P adsorption capacity by activated biochar using ZnCl2 (15,460 mg kg(-1)) was higher than that of typical biochar, as determined by the Langmuir adsorption isotherm. Therefore, the ZnCl2 activation of sesame straw biochar was suitable for the preparation of activated biochar for P adsorption.

  18. Non-Destructive Evaluation of Thermal Spray Coating Interface Quality by Eddy Current Method

    SciTech Connect

    B.Mi; X. Zhao; R. Bayles

    2006-05-26

    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.

  19. Formation of P3KHT:PCBM bulk-heterojunction using orthogonal solvents by ultrasonic spray method

    NASA Astrophysics Data System (ADS)

    Mahajan, Mrunal S.; Lonkar, Ganesh S.; Ghosh, Sanjay S.; Patil, Mahendra B.; Dalal, Dipak S.; Sali, Jaydeep V.

    2015-07-01

    Bulk-heterojunction (BHJ) morphologies with pure domains and sharp interfaces can lead to a more pronounced photovoltaic performance in organic solar cells. In this paper we report the formation of bulk-heterojunction of P3KHT (poly [3-(sodium-6 hexanoate) thiophene-2, 5-diyl]) and PCBM (phenyl-C61-butyric acid methyl ester) using orthogonal solvents by the ultrasonic spray method, which can lead to pure phases and sharp interfaces. P3KHT and PCBM are soluble in water and chlorobenzene respectively, which are orthogonal solvents. The modelling and simulation of the ultrasonic spray method is reported, and shows the possibility of formation of interconnecting phases of the two components in P3KHT:PCBM BHJ, formed using orthogonal solvents, if specific process parameters are chosen. The modelling and simulation also presents a way to determine optimum parameter space in an intermittent spray deposition method using orthogonal solvents. P3KHT:PCBM BHJ has been prepared using three different approaches. Significant photoluminescence quenching, suggesting efficient excitons separation before recombination has been observed in BHJ prepared by the ‘emulsion of solutions’ method. The study of the optical properties of P3KHT:PCBM BHJ suggests that the BHJ may contain bilayer type structures embedded in the BHJ morphology, which is further confirmed by complementary experiments. This new approach to preparing BHJ with pure phase domains and sharp donor/acceptor interfaces may find applications in optoelectronic devices such as organic thin-film transistors, photodetectors, organic light emitting diodes and organic solar cells.

  20. Optical and electrical characteristics of pyrite films prepared by a new spray method using PVDF as a polymeric binder

    NASA Astrophysics Data System (ADS)

    Javad Zanganeh, Mohammad; Ziarati, Mahmoud; Khandan, Nahid; Goudarzi, Ali Reza

    2015-06-01

    Pyrite thin films were deposited on glass substrates by a new and simple spray method using polyvinylidene fluoride as polymeric binder. Prepared pyrite films were characterized by field emission scanning electron microscopy, ultraviolet-visible spectroscopy and Hall auto-measuring instrument. Hall measurements showed p-type conduction of all the prepared thin films. The film prepared by using binder concentration of 2 wt.% showed the best results. Its band gap was estimated 1.55 eV. Also, electrical characteristics of the deposited film were obtained by I-V characteristic curve.

  1. 10 CFR 431.264 - Uniform test method for the measurement of flow rate for commercial prerinse spray valves.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... commercial prerinse spray valves. 431.264 Section 431.264 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Prerinse Spray... prerinse spray valves. (a) Scope. This section provides the test procedure for measuring, pursuant to...

  2. 10 CFR 431.264 - Uniform test method for the measurement of flow rate for commercial prerinse spray valves.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... commercial prerinse spray valves. 431.264 Section 431.264 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Prerinse Spray... prerinse spray valves. (a) Scope. This section provides the test procedure for measuring, pursuant to...

  3. 10 CFR 431.264 - Uniform test method for the measurement of flow rate for commercial prerinse spray valves.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... commercial prerinse spray valves. 431.264 Section 431.264 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Prerinse Spray... prerinse spray valves. (a) Scope. This section provides the test procedure for measuring, pursuant to...

  4. Pyrolysis: theory and industrial practice

    SciTech Connect

    Albright, L.F.; Crynes, B.L.; Corcoran, W.H.

    1983-01-01

    This book is useful for the study of pyrolysis from two perspectives: theory and industrial practice. Topics included are thermal decompositions and reactions of methane pyrolysis of ethane and propane, pyrolysis of n-butane, thermal reaction of olefins and diolefins, pyrolysis of heavy hydrocarbons, formation of aromatics, hydrogenolysis of toluene, mathematical modeling of hydrocarbon pyrolysis reactions, nonpetroleum feedstocks, formation and gasification of coke, surface reactions in pyrolysis units, pyrolysis furnace design, laboratory reactors for pyrolysis, and economic considerations in the design and operation of conventional pyrolysis furnaces.

  5. 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)

    Shakkottai, Parthasarathy (Inventor); Kwack, Eug Y. (Inventor); Lawson, Daniel D. (Inventor)

    1991-01-01

    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.

  6. Scalable synthesis of mesoporous titania microspheres via spray-drying method.

    PubMed

    Pal, Manas; Wan, Li; Zhu, Yongheng; Liu, Yupu; Liu, Yang; Gao, Wenjun; Li, Yuhui; Zheng, Gengfeng; Elzatahry, Ahmed A; Alghamdi, Abdulaziz; Deng, Yonghui; Zhao, Dongyuan

    2016-10-01

    Mesoporous TiO2 has several potential applications due to its unique electronic and optical properties, although its structures and morphologies are typically difficult to tune because of its uncontrollable and fast sol-gel reaction. In this study we have coupled the template-directed-sol-gel-chemistry with the low-cost, scalable, and environmentally benign aerosol (spray-drying) one-pot preparation technique for the fabrication of hierarchically mesoporous TiO2 microspheres and Fe3O4@mesoporous TiO2-x microspheres in a large scale. Parameters during the pre-hydrolysis and spray-drying treatment were varied to successfully control the bead diameter, morphology, monodispersity, surface area and pore size for improving their effectiveness for better application. Unlike to the previous aerosol synthetic approaches, where mainly quite a high temperature gradient with the strict control of spray-drying precursor concentration is implied, our strategy is lying on comparatively low drying temperature with an additional post-ultrasonication (further hydrolysis and condensation) route of the pre-calcined TiO2 samples. As-synthesized mesoporous microspheres have a size distribution from 500nm to 5μm, specific surface areas ranging from 150 to 162m(2)g(-1) and mean pore sizes of several nanometers (4-6nm). Further Fe3O4@mesoporous TiO2-x microspheres were observed to show remarkable selective phosphopeptide-enrichment activity which might have significant importance in disease diagnosis and other biomedical applications.

  7. Kinetics study on conventional and microwave pyrolysis of moso bamboo.

    PubMed

    Dong, Qing; Xiong, Yuanquan

    2014-11-01

    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.

  8. Kinetics study on conventional and microwave pyrolysis of moso bamboo.

    PubMed

    Dong, Qing; Xiong, Yuanquan

    2014-11-01

    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

  9. Method of forming a plasma sprayed interconnection layer on an electrode of an electrochemical cell

    DOEpatents

    Spengler, Charles J.; Folser, George R.; Vora, Shailesh D.; Kuo, Lewis; Richards, Von L.

    1995-01-01

    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.

  10. Method of forming a plasma sprayed interconnection layer on an electrode of an electrochemical cell

    DOEpatents

    Spengler, C.J.; Folser, G.R.; Vora, S.D.; Kuo, L.; Richards, V.L.

    1995-06-20

    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.

  11. Thermal Arc Spray Overview

    NASA Astrophysics Data System (ADS)

    Hafiz Abd Malek, Muhamad; Hayati Saad, Nor; Kiyai Abas, Sunhaji; Mohd Shah, Noriyati

    2013-06-01

    Usage of protective coating for corrosion protection was on highly demand during the past decade; and thermal spray coating played a major part during that time. In recent years, the thermal arc spray coating becomes a popular coating. Many big players in oil and gas such as PETRONAS, EXXON MOBIL and SHELL in Malaysia tend to use the coating on steel structure as a corrosion protection. Further developments in coating processes, the devices, and raw materials have led to expansion of functional coatings and applications scope from conventional coating to specialized industries. It is widely used because of its ability to withstand high process temperature, offer advantages in efficiency, lower cost and acts as a corrosion protection. Previous research also indicated that the thermal arc spray offers better coating properties compared to other methods of spray. This paper reviews some critical area of thermal spray coating by discussing the process/parameter of thermal arc spray technology and quality control of coating. Coating performance against corrosion, wear and special characteristic of coating are also described. The field application of arc spray technology are demonstrated and reviewed.

  12. Spray atomization of bio-oil/ethanol blends with externally mixed nozzles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Experiments were conducted to investigate the properties of sprays of pyrolysis oil from biomass (bio-oil) using an air assisted atomization nozzle operated without combustion to explore the potential of pyrolysis oil combustion in industrial and home furnaces. Bio-oil was blended with ethanol to im...

  13. Carbon nanoscrolls by pyrolysis of a polymer

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

    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.

  14. Application of ultrasound to microencapsulation of coconut milk fat by spray drying method.

    PubMed

    Le, Hoang Du; Le, Van Viet Man

    2015-04-01

    Mixtures of coconut milk and gelatin solution were treated by ultrasound, mixed with maltodextrin and subsequently spray-dried to yield powder. The effects of ultrasonic power and sonication time on the microencapsulation efficiency (ME) and microencapsulation yield (MY) of coconut fat were investigated. The results indicated that increase in ultrasonic power from 0 to 5.68 W/g and in sonication time from 0 to 2.5 min augmented ME and MY of coconut fat. However, treatment with sonication power higher than 5.68 W/g led to a drop in fat ME and MY, mainly due to aggregation of fat particles and that blocked the adsorption of gelatin molecules on the particle surface. PMID:25829636

  15. Fabrication of multifunctional cellulose nanocrystals/poly(lactic acid) nanocomposites with silver nanoparticles by spraying method.

    PubMed

    Yu, Hou-Yong; Yang, Xing-Yuan; Lu, Fang-Fang; Chen, Guo-Yin; Yao, Ju-Ming

    2016-04-20

    The poly (lactic acid) (PLA)/functionalized cellulose nanocrystals formates (CNFs) were prepared by solution casting and then the binary films were sprayed with silver ammonia aqueous solution to fabricate PLA/CNF/Ag ternary nanocomposites. It was found that both deposited silver (Ag) nanoparticles and CNFs showed efficient reinforcing effect on the thermal, mechanical, barrier properties and antibacterial activity of PLA matrix. Especially, the maximum decomposition temperature (Tmax) and Young's modulus of PLA/CNF/Ag(6) nanocomposite film increased by 15.5°C and 48.7%, respectively. Meanwhile an obvious reduction in the water vapor permeability was detected. Furthermore, the migration levels of the ternary nanocomposite films were well below the permitted limits in both non-polar and polar food simulants (60mgkg(-1)), and they showed a significant antibacterial activity influenced by the Ag contents. This study reveals that the novel nanocomposite films will offer a good perspective for food packaging applications. PMID:26876846

  16. High drug load, stable, manufacturable and bioavailable fenofibrate formulations in mesoporous silica: a comparison of spray drying versus solvent impregnation methods.

    PubMed

    Hong, Shiqi; Shen, Shoucang; Tan, David Cheng Thiam; Ng, Wai Kiong; Liu, Xueming; Chia, Leonard S O; Irwan, Anastasia W; Tan, Reginald; Nowak, Steven A; Marsh, Kennan; Gokhale, Rajeev

    2016-01-01

    Encapsulation of drugs in mesoporous silica using co-spray drying process has been recently explored as potential industrial method. However, the impact of spray drying on manufacturability, physiochemical stability and bioavailability in relation to conventional drug load processes are yet to be fully investigated. Using a 2(3) factorial design, this study aims to investigate the effect of drug-loading process (co-spray drying and solvent impregnation), mesoporous silica pore size (SBA-15, 6.5 nm and MCM-41, 2.5 nm) and percentage drug load (30% w/w and 50% w/w) on material properties, crystallinity, physicochemical stability, release profiles and bioavailability of fenofibrate (FEN) loaded into mesoporous silica. From the scanning electronic microscopy (SEM) images, powder X-ray diffraction and Differential scanning calorimetry measurements, it is indicated that the co-spray drying process was able to load up to 50% (w/w) FEN in amorphous form onto the mesoporous silica as compared to the 30% (w/w) for solvent impregnation. The in vitro dissolution rate of the co-spray dried formulations was also significantly (p = 0.044) better than solvent impregnated formulations at the same drug loading. Six-month accelerated stability test at 40 °C/75 RH in open dish indicated excellent physical and chemical stability of formulations prepared by both methods. The amorphous state of FEN and the enhanced dissolution profiles were well preserved, and very low levels of degradation were detected after storage. The dog data for the three selected co-spray-dried formulations revealed multiple fold increment in FEN bioavailability compared to the reference crystalline FEN. These results validate the viability of co-spray-dried mesoporous silica formulations with high amorphous drug load as potential drug delivery systems for poorly water soluble drugs.

  17. Application of ZnO films to glass substrates by the dipping-pyrolysis method using organic acid salt

    NASA Astrophysics Data System (ADS)

    Kondow, Takeshi; Ninomiya, Kanae

    1992-12-01

    Transparent ZnO films having more than 1 micrometers in thickness were prepared by one dipping-pyrolysis process. The starting solution, produced by dissolving zinc 2- ethylhexanoate, dehydrated caster oil fatty acid and dimethyl silicone oil as a leveling agent into an organic solvent, was coated on the plate glass and cured at 200 degree(s)C and heated up to 500 degree(s)C. The thick ZnO films covered with SiO2 films are very useful for UV cut-offs at about 380 nm and for high transparency in the visible region. The ZnO films with the durable films have a possible application to automobile windows and the like. Characterizations are also reported by scanning electron microscopy (SEM), X-ray diffraction (XRD), secondary ion mass spectrometry (SIMS), optical spectroscopy and Taber abrasion test.

  18. Bulk heterojunction thin film formation by single and dual feed ultrasonic spray method for application in organic solar cells

    NASA Astrophysics Data System (ADS)

    Marathe, D. M.; Tarkas, H. S.; Mahajan, M. S.; Lonkar, G. S.; Tak, S. R.; Sali, J. V.

    2016-09-01

    We here present a way of preparing the polymer: fullerene BHJ using dual feed method which can lead to formation of pure phases. In this report, we present results of our initial experiments in this direction. The effect of process parameters on the thickness and surface roughness of the active layer has been discussed. The structural and optical properties have been studied using the optical microscope, UV—visible spectroscopy and photoluminescence spectroscopy. Significant PL quenching indicates efficient charge separation in the BHJ formed using this technique. We have also compared the BHJ thin films prepared with this dual feed ultrasonic technique with the single feed spray method. The BHJ formed using this technique has been used as an active layer in OSC. supported by the University Grants Commission, New Delhi, under Faculty Improvement Programme (No. 33-02/12(WRO) Dt.19.03.2013) and the Special Assistance Programme (530/2/DRS/2010(SAP-I)) Phase-II.

  19. Review of NMR characterization of pyrolysis oils

    DOE PAGESBeta

    Hao, Naijia; Ben, Haoxi; Yoo, Chang Geun; Adhikari, Sushil; Ragauskas, Arthur J.

    2016-08-24

    Here, pyrolysis of renewable biomass has been developed as a method to produce green fuels and chemicals in response to energy security concerns as well as to alleviate environmental issues incurred with fossil fuel usage. However, pyrolysis oils still have limited commercial application, mainly because unprocessed oils cannot be readily blended with current petroleum-based transportation fuels. To better understand these challenges, researchers have applied diverse characterization techniques in the development of bio-oil studies. In particular, nuclear magnetic resonance (NMR) is a key spectroscopic characterization method through analysis of bio-oil components. This review highlights the NMR strategies for pyrolysis oil characterizationmore » and critically discusses the applications of 1H, 13C, 31P, 19F, and two-dimensional (2-D NMR) analyses such as heteronuclear single quantum correlation (HSQC) in representative pyrolysis oil studies.« less

  20. Supersonic-Spray Cleaner

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

    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.

  1. Taste-masking effect of physical and organoleptic methods on peppermint-scented orally disintegrating tablet of famotidine based on suspension spray-coating method.

    PubMed

    Sugiura, Takeshi; Uchida, Shinya; Namiki, Noriyuki

    2012-01-01

    Orally disintegrating tablets (ODTs) are useful for improving benefits for patients of various ages. Masking the unpleasant taste of a drug is an important factor in the compliance of patients who take ODTs. We evaluated the taste acceptability effects of various taste-masking methods on bitter famotidine ODTs as a clinical pharmacological study. The following methods were tested to compare taste-masking effects: physical masking by spray-coating famotidine with ethyl cellulose versus organoleptic masking with added sweetener and flavor. The ODT samples were prepared as single or combinations of each taste-masking method using a novel suspension spray-coating method including a placebo. A total of 31 healthy volunteers were enrolled in this randomized, double-blind study and asked to score their bitterness, sweetness and total palate impressions by 100 mm visual analogue scale (VAS). VAS scores were significantly improved by the physical and organoleptic methods as compared to without taste-masked ODTs. Furthermore, the combination of both taste-masking methods was most effective for improving palatability and VAS scores were similar to those of placebo ODTs. The results of this study suggest that different taste-masking mechanisms function cooperatively.

  2. Taste-masking effect of physical and organoleptic methods on peppermint-scented orally disintegrating tablet of famotidine based on suspension spray-coating method.

    PubMed

    Sugiura, Takeshi; Uchida, Shinya; Namiki, Noriyuki

    2012-01-01

    Orally disintegrating tablets (ODTs) are useful for improving benefits for patients of various ages. Masking the unpleasant taste of a drug is an important factor in the compliance of patients who take ODTs. We evaluated the taste acceptability effects of various taste-masking methods on bitter famotidine ODTs as a clinical pharmacological study. The following methods were tested to compare taste-masking effects: physical masking by spray-coating famotidine with ethyl cellulose versus organoleptic masking with added sweetener and flavor. The ODT samples were prepared as single or combinations of each taste-masking method using a novel suspension spray-coating method including a placebo. A total of 31 healthy volunteers were enrolled in this randomized, double-blind study and asked to score their bitterness, sweetness and total palate impressions by 100 mm visual analogue scale (VAS). VAS scores were significantly improved by the physical and organoleptic methods as compared to without taste-masked ODTs. Furthermore, the combination of both taste-masking methods was most effective for improving palatability and VAS scores were similar to those of placebo ODTs. The results of this study suggest that different taste-masking mechanisms function cooperatively. PMID:22382410

  3. Zone heating for fluidized bed silane pyrolysis

    NASA Technical Reports Server (NTRS)

    Iya, Sridhar K. (Inventor)

    1987-01-01

    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.

  4. Catalytic pyrolysis of wheat bran for hydrocarbons production in the presence of zeolites and noble-metals by using TGA-FTIR method.

    PubMed

    Lazdovica, K; Liepina, L; Kampars, V

    2016-05-01

    Pyrolysis of wheat bran with or without catalysts was investigated using TGA-FTIR method in order to determine the influence of zeolite and noble metal catalysts on the evolution profile and relative yield of the volatile compounds. The addition of all catalysts decreased the volatile matter of wheat bran from 76.3% to 75.9%, 73.9%, 73.5%, 69.7% and increased the solid residue from 18.0% to 18.4%, 20.4%, 20.8%, 24.6% under the catalyst of ZSM-5, 5% Pd/C, MCM-41, and 5% Pt/C. Noble-metal catalysts had higher activity for deoxygenation of compounds containing carbonyl, carboxyl, and hydroxyl groups than zeolites. Degradation of nitrogen containing compounds atom proceeded better in presence of zeolites. Noble-metal catalysts promoted formation of aromatics and changed the profiles of evolved compounds whereas zeolites advanced formation of aliphatics and olefins.

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

    PubMed

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

    2015-03-01

    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 1.42 Nm(3)/kg(blend fuel), 10.57 MJ/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.

  6. [Preparation and characterization of tetrandrine-loaded PLGA nanocomposite particles by premix membrane emulsification coupled with spray-drying method].

    PubMed

    Hu, Tao; Zhu, Hua-Xu; Guo, Li-Wei; Pan, Lin-Mei; Li, Bo; Shi, Fei-Yan; Lu, Jin

    2014-11-01

    For effective inhalable dry-powder drug delivery, tetrandrine-PLGA (polylactic-co-glycolic acid) nanocomposite particles have been developed to overcome the disadvantages of nanoparticles and microparticles. The primary nanoparticles were prepared by using premix membrane emulsification method. To prepare second particles, they were spray dried. The final particles were characterized by scanning electron microscopy (SEM), dry laser particle size analysis, high performance liquid chromatography (HPLC), X-ray diffraction (XRD), differential scanning calorimetry (DSC), infrared analysis (IR) and confocal laser scanning microscope (CLSM). The average size of the primary particles was (337.5 ± 6.2) nm, while that second particles was (3.675 ± 0.16) μm which can be decomposed into primary nanoparticles in water. And the second particles were solid sphere-like with the drug dispersed as armorphous form in them. It is a reference for components delivery to lung in a new form. PMID:25757290

  7. Pyrolysis system evaluation study

    NASA Technical Reports Server (NTRS)

    1974-01-01

    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.

  8. Method and apparatus for discharging treated coal and controlling emissions from a heavy oil spray system

    SciTech Connect

    Skinner, J.L.

    1986-10-07

    An apparatus is described for discharging heavy oil-treated particulate coal and controlling emissions from a heavy oil spray contacting vessel for contacting particulate coal and heavy oil. The contacting vessel includes a contacting zone into which the heavy oil is injected as a mist to initimately contact the coal as the coal falls through the contacting zone. The apparatus consists of: (a) a discharge chute positioned to receive the heavy oil-treated coal from the lower end of the contacting vessel and discharge the heavy oil-treated coal from a discharge chute outlet positioned on the lower end of the discharge chute; (b) a conveyor belt positioned at a distance beneath the discharge chute outlet so that when the conveyor belt is stopped, a bed of the heavy oil-treated coal is retained in the discharge chute and when the conveyor belt is activated controlled quantities of the heavy oil-treated coal are discharged through the discharge chute outlet at a rate such that the bed of heavy oil-treated coal is retained in the discharge chute; and, (c) a drive means for driving the conveyor belt at a selected rate.

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

    DOEpatents

    Smith, Richard D.

    1988-01-01

    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.

  10. Nitroglycerin Spray

    MedlinePlus

    ... artery disease (narrowing of the blood vessels that supply blood to the heart). The spray may also ... Innopran XL), sotalol (Betapace, Sorine), and timolol; calcium channel blockers such as amlodipine (Norvasc, in Tekamlo), diltiazem ( ...

  11. Preparation and Characterization of the Solid Spherical HMX/F2602 by the Suspension Spray-Drying Method

    NASA Astrophysics Data System (ADS)

    Ji, Wei; Li, Xiaodong; Wang, Jingyu; Ye, Baoyun; Wang, Cailing

    2016-10-01

    Solid spherical octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine/fluororubber2602 (HMX/F2602) was prepared by the suspension spray-drying method as follows: firstly, thinning octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) was obtained by a solvent-anti-solvent method. Secondly, thinning HMX suspended in ethyl acetate solvent in a solution of a binder-F2602-was made into a suspension. Finally, the samples were prepared by spray drying. The samples were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectrometry (XPS), X-ray diffraction (XRD), and Fourier transform infrared (FTIR), and its thermal stability as well as mechanical and spark sensitivities were measured. The results of SEM showed that the grain of HMX/F2602 was solid spherical and the particle distribution was homogeneous. The results of XPS indicated that F2602 can be successfully coated on the surface of HMX crystals. Compared to raw HMX, th characteristic drop height was increased from 19.60 to 40.37 cm, an increase of 79.10%. The friction sensitivities of HMX reduced from 100 to 28% and the spark sensitivity of HMX/F2602 increased. The critical explosion temperatures of raw HMX and HMX/F2602 were 275.43 and 274.30°C, respectively. The amount of gas evolution of raw HMX and HMX/F2602 was 0.15 and 0.12 ml.(5 g)-1, respectively. The results of DSC and vacuum stability tests (VSTs) indicate that the thermal stability of HMX/F2602 was equal to that of raw HMX and HMX and F2602 had good compatibility.

  12. Vacuum Plasma Spraying Replaces Electrodeposition

    NASA Technical Reports Server (NTRS)

    Holmes, Richard R.; Power, Chris; Burns, David H.; Daniel, Ron; Mckechnie, Timothy N.

    1992-01-01

    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.

  13. Preparation of Pt supported on WO 3-C with enhanced catalytic activity by microwave-pyrolysis method

    NASA Astrophysics Data System (ADS)

    Ye, Jilei; Liu, Jianguo; Zou, Zhigang; Gu, Jun; Yu, Tao

    The WO 3-C hybrid materials are prepared by intermittently microwave-pyrolysis using ammonium tungstate as the precursor, and then Pt nano-particles are deposited by microwave-assited polyol process on WO 3-C. The TEM images show the dispersion of ∼10 nm WO 3 particles size supported on carbon and ∼3 nm Pt metal crystallites supported on WO 3-C. XRD results illustrate that WO 3 presented as monoclinic phase and the content of WO 3 in WO 3/C and Pt/WO 3-C catalysts is further characterized by EDAX. Furthermore, XPS characterizations indicate that the interaction between Pt and WO 3 is dramatically enhanced after heat treatment at 200 °C. The activities of Pt/WO 3-C for the electrochemical oxidation of methanol are compared with Pt/C in acid solution by cyclic voltammetry, CO-stripping and chronoaperometry. Pt/WO 3-C catalyst calcined at 200 °C exhibits the highest activity per electrochemical active surface area for methanol oxidation and is 60 mV more negative for CO electro-oxidation than that of Pt/C and Pt/WO 3-C without heat treatment. The great enhancement of electrochemical performance may be due to the improvement of the synergistic effect between Pt and WO 3 in Pt/WO 3-C catalyst after heat treatment.

  14. 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...

  15. Pyrolysis with staged recovery

    DOEpatents

    Green, Norman W.; Duraiswamy, Kandaswamy; Lumpkin, Robert E.; Winter, Bruce L.

    1979-03-20

    In a continuous process for recovery of values contained in a solid carbonaceous material, the carbonaceous material is comminuted and then subjected to flash pyrolysis in the presence of a particulate heat source fed over an overflow weir to form a pyrolysis product stream containing a carbon containing solid residue and volatilized hydrocarbons. After the carbon containing solid residue is separated from the pyrolysis product stream, values are obtained by condensing volatilized hydrocarbons. The particulate source of heat is formed by oxidizing carbon in the solid residue.

  16. Simulations of Spray Reacting Flows in a Single Element LDI Injector With and Without Invoking an Eulerian Scalar PDF Method

    NASA Technical Reports Server (NTRS)

    Shih, Tsan-Hsing; Liu, Nan-Suey

    2012-01-01

    This paper presents the numerical simulations of the Jet-A spray reacting flow in a single element lean direct injection (LDI) injector by using the National Combustion Code (NCC) with and without invoking the Eulerian scalar probability density function (PDF) method. The flow field is calculated by using the Reynolds averaged Navier-Stokes equations (RANS and URANS) with nonlinear turbulence models, and when the scalar PDF method is invoked, the energy and compositions or species mass fractions are calculated by solving the equation of an ensemble averaged density-weighted fine-grained probability density function that is referred to here as the averaged probability density function (APDF). A nonlinear model for closing the convection term of the scalar APDF equation is used in the presented simulations and will be briefly described. Detailed comparisons between the results and available experimental data are carried out. Some positive findings of invoking the Eulerian scalar PDF method in both improving the simulation quality and reducing the computing cost are observed.

  17. Rapid Microcystin Determination Using a Paper Spray Ionization Method with a Time-of-Flight Mass Spectrometry System.

    PubMed

    Zhu, Xiaoqiang; Huang, Zhengxu; Gao, Wei; Li, Xue; Li, Lei; Zhu, Hui; Mo, Ting; Huang, Bao; Zhou, Zhen

    2016-07-13

    The eutrophication of surface water sources and climate changes have resulted in an annual explosion of cyanobacterial blooms in many irrigating and drinking water resources. To decrease health risks to the public, a rapid real time method for the synchronous determination of two usually harmful microcystins (MC-RR and MC-LR) in environmental water samples was built by employing a paper spray ionization method coupled with a time-of-flight mass spectrometer system. With this approach, direct analysis of microcystin mixtures without sample preparation has been achieved. Rapid detection was performed, simulating the release process of microcystins in reservoir water samples, and the routine detection frequency was every three minutes. The identification time of microcystins was reduced from several hours to a few minutes. The limit of detection is 1 μg/L, and the limit of quantitation is 3 μg/L. This method displays the ability for carrying out rapid, direct, and high-throughput experiments for determination of microcystins, and it would be of significant interest for environmental and food safety applications.

  18. Rapid Microcystin Determination Using a Paper Spray Ionization Method with a Time-of-Flight Mass Spectrometry System.

    PubMed

    Zhu, Xiaoqiang; Huang, Zhengxu; Gao, Wei; Li, Xue; Li, Lei; Zhu, Hui; Mo, Ting; Huang, Bao; Zhou, Zhen

    2016-07-13

    The eutrophication of surface water sources and climate changes have resulted in an annual explosion of cyanobacterial blooms in many irrigating and drinking water resources. To decrease health risks to the public, a rapid real time method for the synchronous determination of two usually harmful microcystins (MC-RR and MC-LR) in environmental water samples was built by employing a paper spray ionization method coupled with a time-of-flight mass spectrometer system. With this approach, direct analysis of microcystin mixtures without sample preparation has been achieved. Rapid detection was performed, simulating the release process of microcystins in reservoir water samples, and the routine detection frequency was every three minutes. The identification time of microcystins was reduced from several hours to a few minutes. The limit of detection is 1 μg/L, and the limit of quantitation is 3 μg/L. This method displays the ability for carrying out rapid, direct, and high-throughput experiments for determination of microcystins, and it would be of significant interest for environmental and food safety applications. PMID:27345366

  19. Thermal spray processing

    NASA Technical Reports Server (NTRS)

    Herman, H.; Berndt, C. C.

    1995-01-01

    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.

  20. Structure, magnetic, and dielectric properties of Ti-doped LaFeO{sub 3} ceramics synthesized by polymer pyrolysis method

    SciTech Connect

    Phokha, Sumalin; Hunpratup, Sitchai; Pinitsoontorn, Supree; Putasaeng, Bundit; Rujirawat, Saroj; Maensiri, Santi

    2015-07-15

    Highlights: • The LaFe{sub 1−x}Ti{sub x}O{sub 3} samples can be successfully prepared by polymer pyrolysis method. • XANES spectra confirmed the mixed valence states of Fe{sup 3+} and Fe{sup 4+} for Fe ions and valence states of Ti{sup 4+} for Ti ions. • The ferromagnetism (FM) at room temperature (RT) can be observed in all LaFe{sub 1−x}Ti{sub x}O{sub 3} nanoparticles and ceramics. • The uncompensated spins at the surface played an important role in the magnetism of LaFe{sub 1−x}Ti{sub x}O{sub 3} nanoparticles. • The giant dielectric behavior of the ceramic samples can be easily found by substitution at B site. - Abstract: Perovskite Ti-doped LaFeO{sub 3} (LaFe{sub 1−x}Ti{sub x}O{sub 3}, x = 0, 0.1, and 0.2) nanoparticles synthesized by the polymer pyrolysis method were investigated. X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray absorption near edge spectroscopy (XANES), and vibrating sample magnetometry (VSM) were used to characterize phase, morphology, valence states and magnetic properties of the samples. The samples had a phase of the orthorhombic structure with crystallite sizes of 25 ± 2–47 ± 2 nm for nanoparticles, while ceramic samples had the grain sizes of 0.9 ± 0.3–6.0 ± 2.3 μm. The result of XANES spectra showed that the Fe{sup 3+}/Fe{sup 4+} and Ti{sup 4+} exist in the samples. The weak ferromagnetic behavior at room temperature is observed for all LaFe{sub 1−x}Ti{sub x}O{sub 3} samples with a maximum magnetization of 0.32 emu/g for x = 0.2. Additionally, larger hysteresis loops induced significantly in ceramic samples with no saturation up to 10 kOe. The dielectric properties as a function of frequency at low temperatures suggest the presence of polarization in the samples due to the electron hopping between Fe{sup 3+} and Fe{sup 4+} ions.

  1. Stabilization of Fast Pyrolysis Oil: Post Processing Final Report

    SciTech Connect

    Elliott, Douglas C.; Lee, Suh-Jane; Hart, Todd R.

    2012-03-01

    UOP LLC, a Honeywell Company, assembled a comprehensive team for a two-year project to demonstrate innovative methods for the stabilization of pyrolysis oil in accordance with DOE Funding Opportunity Announcement (FOA) DE-PS36-08GO98018, Biomass Fast Pyrolysis Oil (Bio-oil) Stabilization. In collaboration with NREL, PNNL, the USDA Agricultural Research Service (ARS), Pall Fuels and Chemicals, and Ensyn Corporation, UOP developed solutions to the key technical challenges outlined in the FOA. The UOP team proposed a multi-track technical approach for pyrolysis oil stabilization. Conceptually, methods for pyrolysis oil stabilization can be employed during one or both of two stages: (1) during the pyrolysis process (In Process); or (2) after condensation of the resulting vapor (Post-Process). Stabilization methods fall into two distinct classes: those that modify the chemical composition of the pyrolysis oil, making it less reactive; and those that remove destabilizing components from the pyrolysis oil. During the project, the team investigated methods from both classes that were suitable for application in each stage of the pyrolysis process. The post processing stabilization effort performed at PNNL is described in this report. The effort reported here was performed under a CRADA between PNNL and UOP, which was effective on March 13, 2009, for 2 years and was subsequently modified March 8, 2011, to extend the term to December 31, 2011.

  2. Annealing-free, flexible silver nanowire-polymer composite electrodes via a continuous two-step spray-coating method.

    PubMed

    Choi, Dong Yun; Kang, Hyun Wook; Sung, Hyung Jin; Kim, Sang Soo

    2013-02-01

    For the realization of high-efficiency flexible optoelectronic devices, transparent electrodes should be fabricated through a low-temperature process and have the crucial feature of low surface roughness. In this paper, we demonstrated a two-step spray-coating method for producing large-scale, smooth and flexible silver nanowire (AgNW)-poly3,4-ethylenedioxythiophene:polystyrenesulfonate (PEDOT:PSS) composite electrodes. Without the high-temperature annealing process, the conductivity of the composite film was improved via the lamination of highly conductive PEDOT:PSS modified by dimethyl sulfoxide (DMSO). Under the room temperature process condition, we fabricated the AgNW-PEDOT:PSS composite film showing an 84.3% mean optical transmittance with a 10.76 Ω sq(-1) sheet resistance. The figure of merit Φ(TC) was higher than that obtained from the indium tin oxide (ITO) films. The sheet resistance of the composite film slightly increased less than 5.3% during 200 cycles of tensile and compression folding, displaying good electromechanical flexibility for use in flexible optoelectronic applications. PMID:23241687

  3. Development of method to characterize emissions from spray polyurethane foam insulation

    EPA Science Inventory

    This presentation updates symposium participants re EPA progress towards development of SPF insulation emissions characterization methods. The presentation highlights evaluation of experiments investigating emissions after application of SPF to substrates in micro chambers and i...

  4. Substrate system for spray forming

    DOEpatents

    Chu, Men G.; Chernicoff, William P.

    2002-01-01

    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.

  5. Substrate system for spray forming

    DOEpatents

    Chu, Men G.; Chernicoff, William P.

    2000-01-01

    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.

  6. The effect of mixing methods and polymer infiltration and pyrolysis (PIP) cycles on the densification of silicon carbide inert matrix fuel through a polymer precursor route

    NASA Astrophysics Data System (ADS)

    Shih, Chunghao; Tulenko, J. S.; Baney, R. H.

    2011-12-01

    The effect of mixing methods on the fabrication of silicon carbide (SiC) inert matrix fuel through a polymer precursor route was investigated in order to break up the agglomerates of the SiC particles observed in earlier studies. It was found that a high energy shaker mill could effectively break up the agglomerates and thereby achieve a higher pellet density. Moreover, it was found that the pellet density depended less on the pressing pressure, when the particles are well mixed. SEM images showed cracks caused by the springback effect on pellets with a high cold pressing pressure of 600 MPa, but no signs of springback effect were observed for the 200 MPa pressed pellets. The polymer infiltration and pyrolysis (PIP) cycles were used to further increase the pellet density and close the open pores. The first PIP cycle was found to increase the theoretical density of the pellets from 81.2% to 86.0% and close ˜50% of the open pores. The pore size distribution showed that most of the remaining open pores had diameters smaller than 10 nm. The successive second PIP cycle is not as effective on either the density or the pore size distribution because the small pores present before the second PIP cycle made the infiltration process difficult.

  7. Generation of functional structures by laser pyrolysis of polysilazane

    NASA Astrophysics Data System (ADS)

    Krauss, Hans-Joachim; Otto, Andreas

    2002-06-01

    The pyrolysis of polysilazanes by laser power represents an innovative technique for the generation of ceramic-like coatings and structures. The dissolved polysilazanes can be easily applied by painting techniques such as dipping or spraying. In the following pyrolysis the polysilazane layer transforms into an amorphous ceramic-like coating. The laser power is absorbed in the precursor layer, which leads to the latter's ceramization without damaging the substrate by thermal load. While plane laser pyrolysis creates a protective coating, selective pyrolysis creates a raised and adherent ceramic-like structure that remains after the unexposed polymer layer has been removed. The flexibility of a writing laser system in conjunction with a suitable handling system makes it possible to inscribe any kind of 2D structure on nearly any complexly shaped part. Some of the chemical, magnetic, and electrical structure properties can be adjusted by the pyrolysis parameters and special types of filler particles. Especially the possibility to control electric conductivity should make it possible to create structure dielectric films or planar resistors, inductors or capacitors, which are basically written on the surface of the part. Because of their ceramic nature of the structures are resistant against high temperatures and corrosive media. Thus, this new additive structuring technique could finally strike a new path in creating corrosion resistant high- temperature sensors and control systems.

  8. Plasma spraying method for forming diamond and diamond-like coatings

    DOEpatents

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

    1997-06-03

    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.

  9. Plasma spraying method for forming diamond and diamond-like coatings

    DOEpatents

    Holcombe, Cressie E.; Seals, Roland D.; Price, R. Eugene

    1997-01-01

    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.

  10. Synthesis of nickel oxide nanospheres by a facile spray drying method and their application as anode materials for lithium ion batteries

    SciTech Connect

    Xiao, Anguo Zhou, Shibiao; Zuo, Chenggang; Zhuan, Yongbing; Ding, Xiang

    2015-10-15

    Graphical abstract: NiO nanospheres prepared by a facile spray drying method show high lithium ion storage performance as anode of lithium ion battery. - Highlights: • NiO nanospheres are prepared by a spray drying method. • NiO nanospheres are composed of interconnected nanoparticles. • NiO nanospheres show good lithium ion storage properties. - Abstract: Fabrication of advanced anode materials is indispensable for construction of high-performance lithium ion batteries. In this work, nickel oxide (NiO) nanospheres are fabricated by a facial one-step spray drying method. The as-prepared NiO nanospheres show diameters ranging from 100 to 600 nm and are composed of nanoparticles of 30–50 nm. As an anode for lithium ion batteries, the electrochemical properties of the NiO nanospheres are investigated by cyclic voltammetry (CV) and galvanostatic charge/discharge tests. The specific reversible capacity of NiO nanospheres is 656 mA h g{sup −1} at 0.1 C, and 476 mA h g{sup −1} at 1 C. The improvement of electrochemical properties is attributed to nanosphere structure with large surface area and short ion/electron transfer path.

  11. Agricultural Spraying

    NASA Technical Reports Server (NTRS)

    1986-01-01

    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.

  12. Development of an efficient transformation method by Agrobacterium tumefaciens and high throughput spray assay to identify transgenic plants for woodland strawberry (Fragaria vesca) using NPTII selection.

    PubMed

    Pantazis, Christopher J; Fisk, Sarah; Mills, Kerri; Flinn, Barry S; Shulaev, Vladimir; Veilleux, Richard E; Dan, Yinghui

    2013-03-01

    KEY MESSAGE : We developed an efficient Agrobacterium -mediated transformation method using an Ac/Ds transposon tagging construct for F. vesca and high throughput paromomycin spray assay to identify its transformants for strawberry functional genomics. Genomic resources for Rosaceae species are now readily available, including the Fragaria vesca genome, EST sequences, markers, linkage maps, and physical maps. The Rosaceae Genomic Executive Committee has promoted strawberry as a translational genomics model due to its unique biological features and transformability for fruit trait improvement. Our overall research goal is to use functional genomic and metabolic approaches to pursue high throughput gene discovery in the diploid woodland strawberry. F. vesca offers several advantages of a fleshy fruit typical of most fruit crops, short life cycle (seed to seed in 12-16 weeks), small genome size (206 Mbb/C), small plant size, self-compatibility, and many seeds per plant. We have developed an efficient Agrobacterium tumefaciens-mediated strawberry transformation method using kanamycin selection, and high throughput paromomycin spray assay to efficiently identify transgenic strawberry plants. Using our kanamycin transformation method, we were able to produce up to 98 independent kanamycin resistant insertional mutant lines using a T-DNA construct carrying an Ac/Ds transposon Launchpad system from a single transformation experiment involving inoculation of 22 leaf explants of F. vesca accession 551572 within approx. 11 weeks (from inoculation to soil). Transgenic plants with 1-2 copies of a transgene were confirmed by Southern blot analysis. Using our paromomycin spray assay, transgenic F. vesca plants were rapidly identified within 10 days after spraying.

  13. Microemulsion flame pyrolysis for hopcalite nanoparticle synthesis: a new concept for catalyst preparation.

    PubMed

    Biemelt, T; Wegner, K; Teichert, J; Kaskel, S

    2015-04-01

    A new route to highly active hopcalite catalysts via flame spray pyrolysis of an inverse microemulsion precursor is reported. The nitrate derived nanoparticles are around 15 nm in diameter and show excellent conversion of CO under ambient conditions, outperforming commercial reference hopcalite materials produced by co-precipitation. PMID:25726946

  14. Microwave-induced pyrolysis of sewage sludge.

    PubMed

    Menéndez, J A; Inguanzo, M; Pis, J J

    2002-07-01

    This paper describes a new method for pyrolyzing sewage sludge using a microwave furnace. It was found that if just the raw wet sludge is treated in the microwave, only drying of the sample takes place. However, if the sludge is mixed with a small amount of a suitable microwave absorber (such as the char produced in the pyrolysis itself) temperatures of up to 900 degrees C can be achieved, so that pyrolysis takes place rather than drying. Microwave treatments were also compared with those carried out in a conventional electric furnace, as well as the characteristics of their respective carbonaceous solid residues.

  15. Toxicity of pyrolysis gases from polytetrafluoroethylene

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Schneider, J. E.

    1979-01-01

    A sample of polytetrafluoroethylene was evaluated for toxicity of pyrolysis gases, using various test conditions of the toxicity screening test method developed at the University of San Francisco. Time to death appears to be affected by the material of which the pyrolysis tube is made, with Monel tending to give longer times to death than quartz. When quartz tubes are used, time to death seems to be related to carbon monoxide concentration. When Monel tubes are used, carbon monoxide does not appear to be the principal toxicant.

  16. Pyrolysis of the tetra pak

    SciTech Connect

    Korkmaz, Ahmet; Yanik, Jale Brebu, Mihai; Vasile, Cornelia

    2009-11-15

    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.

  17. Pharmaceutical spray freeze drying.

    PubMed

    Wanning, Stefan; Süverkrüp, Richard; Lamprecht, Alf

    2015-07-01

    Pharmaceutical spray-freeze drying (SFD) includes a heterogeneous set of technologies with primary applications in apparent solubility enhancement, pulmonary drug delivery, intradermal ballistic administration and delivery of vaccines to the nasal mucosa. The methods comprise of three steps: droplet generation, freezing and sublimation drying, which can be matched to the requirements given by the dosage form and route of administration. The objectives, various methods and physicochemical and pharmacological outcomes have been reviewed with a scope including related fields of science and technology.

  18. Rapid habitability assessment of Mars samples by pyrolysis-FTIR

    NASA Astrophysics Data System (ADS)

    Gordon, Peter R.; Sephton, Mark A.

    2016-02-01

    Pyrolysis Fourier transform infrared spectroscopy (pyrolysis FTIR) is a potential sample selection method for Mars Sample Return missions. FTIR spectroscopy can be performed on solid and liquid samples but also on gases following preliminary thermal extraction, pyrolysis or gasification steps. The detection of hydrocarbon and non-hydrocarbon gases can reveal information on sample mineralogy and past habitability of the environment in which the sample was created. The absorption of IR radiation at specific wavenumbers by organic functional groups can indicate the presence and type of any organic matter present. Here we assess the utility of pyrolysis-FTIR to release water, carbon dioxide, sulfur dioxide and organic matter from Mars relevant materials to enable a rapid habitability assessment of target rocks for sample return. For our assessment a range of minerals were analyzed by attenuated total reflectance FTIR. Subsequently, the mineral samples were subjected to single step pyrolysis and multi step pyrolysis and the products characterised by gas phase FTIR. Data from both single step and multi step pyrolysis-FTIR provide the ability to identify minerals that reflect habitable environments through their water and carbon dioxide responses. Multi step pyrolysis-FTIR can be used to gain more detailed information on the sources of the liberated water and carbon dioxide owing to the characteristic decomposition temperatures of different mineral phases. Habitation can be suggested when pyrolysis-FTIR indicates the presence of organic matter within the sample. Pyrolysis-FTIR, therefore, represents an effective method to assess whether Mars Sample Return target rocks represent habitable conditions and potential records of habitation and can play an important role in sample triage operations.

  19. A new derivatization method for δ18O analysis of individual carbohydrates with GC-Pyrolysis-IRMS

    NASA Astrophysics Data System (ADS)

    Lehmann, M. M.; Siegwolf, R. T.; Saurer, M.; Blees, J.; Fischer, M.; Zech, M.

    2015-12-01

    Compound specific isotope analysis (CSIA) with gas chromatography coupled to an isotope ratio mass spectrometer (GC-Pyr-IRMS) is nowadays a powerful tool that is widely used by a broad spectrum of research fields to investigate the isotopic signature of diverse metabolites. While many CSIA methods for carbon, hydrogen, and nitrogen isotopes are known, CSIA methods for the analysis of oxygen isotopes (δ18O) are still not widely established. Especially, reliable and precise methods for the δ18O analyses of individual carbohydrates are scarce, which is caused by the highly sensitive nature of the sugars. However, carbohydrates are important components of living organisms, source for many biochemical reactions, and can be found in all organisms, in soils, sediments, and in air. Thus, a method, allowing the investigation of the 18O/16O ratio in carbohydrates will enhance the scope of research using isotopes. We developed a new and easy to handle derivatization method to determine δ18O in carbohydrates with GC-Pyr-IRMS that consists of a catalyzed one-pot reaction in acetonitrile, resulting in complete methylation of all sugar hydroxyl groups within 24 hours, with silver oxide as the proton acceptor and methyl iodide as the methyl group carrier. Results derived from standard material show unrivalled δ18O precision ranging from about 0.2 to 1.1 ‰ for different individual carbohydrates of different classes and a generally very good accuracy, with a narrow range of 0.2 ‰ around the reference value, despite of high area variations. We applied this method on real samples, demonstrating that the method can commonly be used for analyzing honey samples, and for the analyses of more complex carbohydrate mixtures from plant leaves, including glucose, fructose, pinitol, and sucrose. Our new method may be used for food, beverage, and medical applications, as well as for biogeochemical and paleoclimatic sciences.

  20. Method of forming a leak proof plasma sprayed interconnection layer on an electrode of an electrochemical cell

    DOEpatents

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

    1995-02-21

    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.

  1. Method of forming a leak proof plasma sprayed interconnection layer on an electrode of an electrochemical cell

    DOEpatents

    Kuo, Lewis J. H.; Vora, Shailesh D.

    1995-01-01

    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.

  2. ENGINEERING BULLETIN: PYROLYSIS TREATMENT

    EPA Science Inventory

    Pyrolysis is formally defined as chemical decomposition induced in organic materials by heat in the absence of oxygen. In practice, it is not possible to achieve a completely oxygen-free atmosphere; actual pyrolytic systems are operated with less than stoichiometric quantities of...

  3. Pyrolysis of Table Sugar

    PubMed Central

    Karagöz, Selhan

    2013-01-01

    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-α-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

  4. Toxicity of pyrolysis gases from polypropylene

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Schneider, J. E.; Brauer, D. F.

    1979-01-01

    A sample of polypropylene was evaluated for toxicity of pyrolysis gases, using the toxicity screening test method developed at the University of San Francisco. The gases from this sample appeared to be equivalent or less toxic than the gases from a sample of polyethylene under these particular test conditions. Carbon monoxide appeared to be the principal toxicant.

  5. Toxicity of pyrolysis gases from foam plastics

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Cumming, H. J.; Casey, C. J.

    1980-01-01

    Twenty-three samples of flexible foams and twelve samples of rigid foams were evaluated for toxicity of pyrolysis gases, using the USF toxicity screening test method. Polychloroprene among the flexible foams, and polystyrene among the rigid foams, appeared to exhibit the least toxicity under these particular test conditions.

  6. Additives initiate selective production of chemicals from biomass pyrolysis.

    PubMed

    Leng, Shuai; Wang, Xinde; Wang, Lei; Qiu, Huizhe; Zhuang, Guilin; Zhong, Xing; Wang, Jianguo; Ma, Fengyun; Liu, Jingmei; Wang, Qiang

    2014-03-01

    To improve chemicals selectivity under low temperature, a new method that involves the injection of additives into biomass pyrolysis is introduced. This method allows biomass pyrolysis to achieve high selectivity to chemicals under low temperature (300°C), while nothing was obtained in typical pyrolysis under 300°C. However, by using the new method, the first liquid drop emerged at the interval between 140°C and 240°C. Adding methanol to mushroom scrap pyrolysis obtained high selectivity to acetic acid (98.33%), while adding ethyl acetate gained selectivity to methanol (65.77%) in bagasse pyrolysis and to acetone (72.51%) in corncob pyrolysis. Apart from basic chemicals, one high value-added chemical (2,3-dihydrobenzofuran) was also detected, which obtained the highest selectivity (10.33%) in corncob pyrolysis through the addition of ethyl acetate. Comparison of HZSM-5 and CaCO3 catalysis showed that benzene emerged in the liquid because of the larger degree of cracking and hydrodeoxygenation over HZSM-5. PMID:24508091

  7. Additives initiate selective production of chemicals from biomass pyrolysis.

    PubMed

    Leng, Shuai; Wang, Xinde; Wang, Lei; Qiu, Huizhe; Zhuang, Guilin; Zhong, Xing; Wang, Jianguo; Ma, Fengyun; Liu, Jingmei; Wang, Qiang

    2014-03-01

    To improve chemicals selectivity under low temperature, a new method that involves the injection of additives into biomass pyrolysis is introduced. This method allows biomass pyrolysis to achieve high selectivity to chemicals under low temperature (300°C), while nothing was obtained in typical pyrolysis under 300°C. However, by using the new method, the first liquid drop emerged at the interval between 140°C and 240°C. Adding methanol to mushroom scrap pyrolysis obtained high selectivity to acetic acid (98.33%), while adding ethyl acetate gained selectivity to methanol (65.77%) in bagasse pyrolysis and to acetone (72.51%) in corncob pyrolysis. Apart from basic chemicals, one high value-added chemical (2,3-dihydrobenzofuran) was also detected, which obtained the highest selectivity (10.33%) in corncob pyrolysis through the addition of ethyl acetate. Comparison of HZSM-5 and CaCO3 catalysis showed that benzene emerged in the liquid because of the larger degree of cracking and hydrodeoxygenation over HZSM-5.

  8. Vaccination of commercial broiler chicks against avian metapneumovirus infection: a comparison of drinking-water, spray and oculo-oral delivery methods.

    PubMed

    Ganapathy, Kannan; Bufton, Andrew; Pearson, Andrew; Lemiere, Stephane; Jones, Richard C

    2010-05-21

    Avian metapneumovirus (aMPV) has become an important cause of viral respiratory infections in turkey and chickens. Live and inactivated vaccinations are available worldwide for prevention of disease and economic losses caused by this pathogen. The efficacy of these vaccines is vigorously tested under laboratory conditions prior to use in the field. In this study, a live subtype B aMPV vaccine was administered by spray, drinking water or oculo-oral methods to separate groups of broiler chicks under field conditions. Following this, the chicks were immediately transferred to separate rooms in an experimental isolation house, monitored and challenged with virulent subtype B aMPV. No clinical signs were recorded following the vaccination methods. In the oculo-oral vaccinated chicks, 40-60% of the birds were vaccine virus positive by RT-PCR. In addition, in comparison to other groups, statistically higher levels of aMPV ELISA antibodies were detected. After spray vaccination, the number of chicks positive for the vaccine virus increased gradually from 10% at one week to 30% by 3 weeks post vaccination. Following drinking water vaccination, 30% of chicks were aMPV positive at 1 week but negative by 3 weeks post vaccination. In both, spray and drinking water vaccinated groups, no ELISA antibodies were detected, but when challenged all chicks were protected against disease. At 5 days post challenge, 100% of chicks in the unvaccinated and those vaccinated by spray or drinking water routes but only 20% of the oculo-oral-vaccinated chicks were aMPV positive by RT-PCR. At 10 days post challenge, 10% of chicks in each group were aMPV RT-PCR positive. On challenge, all vaccinated chicks were protected against disease. It appears that when aMPV vaccine is accurately applied to chicks by spray or drinking water routes, both are capable of giving protection against clinical disease equal to that induced in those chicks vaccinated individually by the oculo-oral route.

  9. The tin precursors and hydrogen peroxide effects on spray-deposited SnO2:F-(n)Si solar cells

    NASA Astrophysics Data System (ADS)

    Adnane, M.; Cachet, H.; Folcher, G.; Hamzaoui, S.; Sahraoui, T.; Bouderbala, M.; Zerdali, M.

    2011-10-01

    The oxide semiconductor compounds such as SnO2, In2O3, ITO, ZnO and others brought about a new attention for the metal-insulator-semiconductor structures as photovoltaic converters because of the high values of transmission and conductivity and the possibility of metal replacement in above-mentioned structures. The characteristics of the solar cells based on these oxide semiconductor compounds can be improved with conductivity increasing of the transparent semiconductor films and that is why the purpose of this paper is obtaining of F-doped tin oxide thin films, preparation of SnO2:F-Si solar cells and studying of their properties. The F-doped tin oxide thin films were prepared by spray pyrolysis technique [1-8]. This method was chosen because of the simplicity of the apparatus and relatively low cost. Aqueous solutions containing 0.1 M (TT, BTT or DTD) and 0.07 M NH4F (in the case of doping with F) have been sprayed by an atomizer on Si or glass substrates, heated up to 420 °C by maintaining the spray liquid volume, the spray time and the pressure of the carrier gas. Spray pyrolysis deposition of transparent and conductive SnO2 is a low-cost and very flexible technique applicable to solar cells. For SnO2, the drawback is that polycrystalline films are only obtained at relatively high deposition temperatures, largely above 450 °C. This constraint may cause damage to the photovoltaic junction. In the present work, it will be demonstrated that the photovoltaic parameters can be influenced by adding small amounts of hydrogen peroxide (H2O2) to the source solution.

  10. Magnetic metal-organic frameworks: γ-Fe2O3@MOFs via confined in situ pyrolysis method for drug delivery.

    PubMed

    Wu, Yi-nan; Zhou, Meimei; Li, Shu; Li, Zehua; Li, Jie; Wu, Baozhen; Li, Guangtao; Li, Fengting; Guan, Xiaohong

    2014-07-23

    A general one-step in situ pyrolysis route for the construction of metal-organic frameworks encapsulating superparamagnetic γ-Fe2O3NPs dispersed in the confined cavities of MOFs homogeneously is described. The integration of γ-Fe2O3 NPs or clusters into MOFs can endow these porous materials with superparamagnetic element. By the combination of the thermal stability of MOFs and pyrolysis of metal triacetylacetonate complex at matched conditions, the porous structure of MOFs are well maintained while the size-induced superparamagnetic property of nano γ-Fe2O3 is obtained. As a proof of concept, both the γ- Fe2O3@ZIF-8 and γ-Fe2O3@MIL-53(Al) were successfully prepared, and the latter was chosen to demonstrate its potential drug delivery as a magnetic MOF. PMID:24644065

  11. Magnetic metal-organic frameworks: γ-Fe2O3@MOFs via confined in situ pyrolysis method for drug delivery.

    PubMed

    Wu, Yi-nan; Zhou, Meimei; Li, Shu; Li, Zehua; Li, Jie; Wu, Baozhen; Li, Guangtao; Li, Fengting; Guan, Xiaohong

    2014-07-23

    A general one-step in situ pyrolysis route for the construction of metal-organic frameworks encapsulating superparamagnetic γ-Fe2O3NPs dispersed in the confined cavities of MOFs homogeneously is described. The integration of γ-Fe2O3 NPs or clusters into MOFs can endow these porous materials with superparamagnetic element. By the combination of the thermal stability of MOFs and pyrolysis of metal triacetylacetonate complex at matched conditions, the porous structure of MOFs are well maintained while the size-induced superparamagnetic property of nano γ-Fe2O3 is obtained. As a proof of concept, both the γ- Fe2O3@ZIF-8 and γ-Fe2O3@MIL-53(Al) were successfully prepared, and the latter was chosen to demonstrate its potential drug delivery as a magnetic MOF.

  12. Acidity of biomass fast pyrolysis bio-oils

    SciTech Connect

    Oasmaa, Anja; Elliott, Douglas C.; Korhonen, Jaana

    2010-12-17

    The use of the TAN method for measuring the acidity of biomass fast pyrolysis bio-oil was evaluated. Suggestions for carrying out the analysis have been made. The TAN method by ASTM D664 or D3339 can be used for measuring the acidity of fast pyrolysis bio-oils and their hydrotreating products. The main difference between the methods is that ASTM D664 is specified for higher TAN values than ASTM D3339. Special focus should be placed on the interpretation of the TAN curves because they differ significantly from those of mineral oils. The curve for bio-oils is so gentle that the automatic detection may not observe the end point properly and derivatization should be used. The acidity of fast pyrolysis bio-oils is mainly derived (60-70%) from volatile acids. Other groups of compounds in fast pyrolysis bio-oils that influence acidity include phenolics, fatty and resin acids, and hydroxy acids.

  13. Pyrolysis process and apparatus

    DOEpatents

    Lee, Chang-Kuei

    1983-01-01

    This invention discloses a process and apparatus for pyrolyzing particulate coal by heating with a particulate solid heating media in a transport reactor. The invention tends to dampen fluctuations in the flow of heating media upstream of the pyrolysis zone, and by so doing forms a substantially continuous and substantially uniform annular column of heating media flowing downwardly along the inside diameter of the reactor. The invention is particularly useful for bituminous or agglomerative type coals.

  14. On methane pyrolysis special applications

    NASA Astrophysics Data System (ADS)

    Toncu, D. C.; Toncu, G.; Soleimani, S.

    2015-11-01

    Methane pyrolysis represents one of the most important processes in industrial use, with applications rising from the chemical and petrochemical industry, combustion, materials and protective coatings. Despite the intense research, experimental data lack kinetic aspects, and the thermodynamics involved often leads to inaccurate results when applied to various systems. Carrying out a comparative analysis of several available data on methane pyrolysis, the paper aims to study the phenomenon of methane pyrolysis under different environments (combustion and plasma), concluding on the most possible reaction pathways involved in many of its applications. Computer simulation using different database underlines the conclusion, helping to the understanding of methane pyrolysis importance in future technologies.

  15. Catalytic pyrolysis of automobile shredder residue

    SciTech Connect

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

    1995-07-01

    In the United States, approximately 10 million automobiles are scrapped and shredded each year. The mixture of plastics and other materials remaining after recovery of the metals is known as Automobile Shredder Residue (ASR). In 1994, about 3.5 million tons of ASR was produced and disposed of in landfills. However, environmental, legislative, and economic considerations are forcing the industry to search for recycling or other alternatives to disposal. Numerous studies have been done relating the ASR disposal problem to possible recycling treatments such as pyrolysis, gasification, co-liquefaction of ASR with coal, chemical recovery of plastics from ASR, catalytic pyrolysis, reclamation in molten salts, and vacuum pyrolysis. These and other possibilities have been studied intensively, and entire symposia have been devoted to the problem. Product mix, yields, toxicology issues, and projected economics of conceptual plant designs based on experimental results are among the key elements of past studies. Because the kinds of recycling methods that may be developed, along with their ultimate economic value, depend on a very large number of variables, these studies have been open-ended. It is hoped that it may be useful to explore some of these previously studied areas from fresh perspectives. One such approach, currently under development at Argonne National Laboratory, is the catalytic pyrolysis of ASR.

  16. Theoretical study of the pyrolysis of vanillin as a model of secondary lignin pyrolysis

    NASA Astrophysics Data System (ADS)

    Wang, Meng; Liu, Chao; Xu, Xiaoxiao; Li, Qibin

    2016-06-01

    The unimolecular and bimolecular decomposition reactions in processes of vanillin pyrolysis were theoretically investigated by employing density functional theory (DFT) method at M06-2X/6-31 G+(d,p) level. The result shows that the homolytic cleavage of O-CH3 bond could be the dominant initial step in the pyrolysis of vanillin. The hydrogen abstractions from functional groups of vanillin by the formed radicals play important roles in the formation of main products. Both formyl, hydroxyl and methoxyl group contribute to the formation of CO. Benzene is formed from the hydrogen addition reaction between hydrogen radical and phenol at high temperature.

  17. Thermal Spraying Coatings Assisted by Laser Treatment

    SciTech Connect

    Fenineche, N. E.; Cherigui, M.

    2008-09-23

    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.

  18. 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)

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

    2014-01-01

    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.

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

    SciTech Connect

    Not Available

    1982-06-01

    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.

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

    PubMed

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

    2013-05-01

    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

  1. Very Large Eddy Simulations of a Jet-A Spray Reacting Flow in a Single Element LDI Injector With and Without Invoking an Eulerian Scalar DWFDF Method

    NASA Technical Reports Server (NTRS)

    Shih, Tsan-Hsing; Liu, Nan-Suey

    2013-01-01

    This paper presents the very large eddy simulations (VLES) of a Jet-A spray reacting flow in a single element lean direct injection (LDI) injector by using the National Combustion Code (NCC) with and without invoking the Eulerian scalar DWFDF method, in which DWFDF is defined as the density weighted time filtered fine grained probability density function. The flow field is calculated by using the time filtered compressible Navier-Stokes equations (TFNS) with nonlinear subscale turbulence models, and when the Eulerian scalar DWFDF method is invoked, the energy and species mass fractions are calculated by solving the equation of DWFDF. A nonlinear subscale model for closing the convection term of the Eulerian scalar DWFDF equation is used and will be briefly described in this paper. Detailed comparisons between the results and available experimental data are carried out. Some positive findings of invoking the Eulerian scalar DWFDF method in both improving the simulation quality and maintaining economic computing cost are observed.

  2. Corrosivity Of Pyrolysis Oils

    SciTech Connect

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

    2011-01-01

    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.

  3. Dynamic characteristics of pulsed supersonic fuel sprays

    NASA Astrophysics Data System (ADS)

    Pianthong, K.; Matthujak, A.; Takayama, K.; Milton, B. E.; Behnia, M.

    2008-06-01

    This paper describes the dynamic characteristics of pulsed, supersonic liquid fuel sprays or jets injected into ambient air. Simple, single hole nozzles were employed with the nozzle sac geometries being varied. Different fuel types, diesel fuel, bio-diesel, kerosene, and gasoline were used to determine the effects of fuel properties on the spray characteristics. A vertical two-stage light gas gun was employed as a projectile launcher to provide a high velocity impact to produce the liquid jet. The injection pressure was around 0.88-1.24 GPa in all cases. The pulsed, supersonic fuel sprays were visualized by using a high-speed video camera and shadowgraph method. The spray tip penetration and velocity attenuation and other characteristics were examined and are described here. An instantaneous spray tip velocity of 1,542 m/s (Mach number 4.52) was obtained. However, this spray tip velocity can be sustained for only a very short period (a few microseconds). It then attenuates very quickly. The phenomenon of multiple high frequency spray pulses generated by a single shot impact and the changed in the angle of the shock structure during the spray flight, which had already been observed in previous studies, is again noted. Multiple shock waves from the conical nozzle spray were also clearly captured.

  4. Kinetics of scrap tyre pyrolysis under vacuum conditions

    SciTech Connect

    Lopez, Gartzen; Aguado, Roberto; Olazar, Martin Arabiourrutia, Miriam; Bilbao, Javier

    2009-10-15

    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.

  5. Kinetics of scrap tyre pyrolysis under vacuum conditions.

    PubMed

    Lopez, Gartzen; Aguado, Roberto; Olazar, Martín; Arabiourrutia, Miriam; Bilbao, Javier

    2009-10-01

    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 12K in the reaction starting temperature. The kinetic constant at 503K for devolatilization of volatile additives at 0.25atm is 1.7 times higher than that at 1atm, and that corresponding to styrene-butadiene rubber at 723K 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.

  6. High-performance graphene/sulphur electrodes for flexible Li-ion batteries using the low-temperature spraying method

    NASA Astrophysics Data System (ADS)

    Kumar, Pushpendra; Wu, Feng-Yu; Hu, Lung-Hao; Ali Abbas, Syed; Ming, Jun; Lin, Chia-Nan; Fang, Jason; Chu, Chih-Wei; Li, Lain-Jong

    2015-04-01

    Elementary sulphur (S) has been shown to be an excellent cathode material in energy storage devices such as Li-S batteries owing to its very high capacity. The major challenges associated with the sulphur cathodes are structural degradation, poor cycling performance and instability of the solid-electrolyte interphase caused by the dissolution of polysulfides during cycling. Tremendous efforts made by others have demonstrated that encapsulation of S materials improves their cycling performance. To make this approach practical for large scale applications, the use of low-cost technology and materials has become a crucial and new focus of S-based Li-ion batteries. Herein, we propose to use a low temperature spraying process to fabricate graphene/S electrode material, where the ink is composed of graphene flakes and the micron-sized S particles prepared by grinding of low-cost S powders. The S particles are found to be well hosted by highly conductive graphene flakes and consequently superior cyclability (~70% capacity retention after 250 cycles), good coulombic efficiency (~98%) and high capacity (~1500 mA h g-1) are obtained. The proposed approach does not require high temperature annealing or baking; hence, another great advantage is to make flexible Li-ion batteries. We have also demonstrated two types of flexible batteries using sprayed graphene/S electrodes.Elementary sulphur (S) has been shown to be an excellent cathode material in energy storage devices such as Li-S batteries owing to its very high capacity. The major challenges associated with the sulphur cathodes are structural degradation, poor cycling performance and instability of the solid-electrolyte interphase caused by the dissolution of polysulfides during cycling. Tremendous efforts made by others have demonstrated that encapsulation of S materials improves their cycling performance. To make this approach practical for large scale applications, the use of low-cost technology and materials has become

  7. Growth, microstructure, optical and electrical properties of sprayed CuInSe{sub 2} polycrystalline films

    SciTech Connect

    Akl, Alaa A.; Afify, H.H.

    2008-06-03

    Polycrystalline thin films of CuInSe{sub 2} have been prepared by chemical spray pyrolysis technique as a function of Cu/In ratio. Incremental growth of the various ratios followed at different substrate temperatures ranging from 548 to 623 K. Characterizations by means of compositional analysis, X-ray diffraction and spectrophotometry measurements have been carried out. Voigt profile method has been used to determine the microstructure parameter (crystallite/domain size and macrostrain). The effect of Cu/In ratio as well as substrate temperature on the optical features (absorption coefficient and band gap) of these films has been investigated. The films of different Cu/In ratios (0.9-1.1) displayed a band gap from 0.92 to 1.025 eV for direct transition. The dark resistivity measurements at room temperature of Cu-rich samples show about five orders of magnitude higher than that of In-rich samples.

  8. Extent of pyrolysis impacts on fast pyrolysis biochar properties.

    PubMed

    Brewer, Catherine E; Hu, Yan-Yan; Schmidt-Rohr, Klaus; Loynachan, Thomas E; Laird, David A; Brown, Robert C

    2012-01-01

    A potential concern about the use of fast pyrolysis rather than slow pyrolysis biochars as soil amendments is that they may contain high levels of bioavailable C due to short particle residence times in the reactors, which could reduce the stability of biochar C and cause nutrient immobilization in soils. To investigate this concern, three corn ( L.) stover fast pyrolysis biochars prepared using different reactor conditions were chemically and physically characterized to determine their extent of pyrolysis. These biochars were also incubated in soil to assess their impact on soil CO emissions, nutrient availability, microorganism population growth, and water retention capacity. Elemental analysis and quantitative solid-state C nuclear magnetic resonance spectroscopy showed variation in O functional groups (associated primarily with carbohydrates) and aromatic C, which could be used to define extent of pyrolysis. A 24-wk incubation performed using a sandy soil amended with 0.5 wt% of corn stover biochar showed a small but significant decrease in soil CO emissions and a decrease in the bacteria:fungi ratios with extent of pyrolysis. Relative to the control soil, biochar-amended soils had small increases in CO emissions and extractable nutrients, but similar microorganism populations, extractable NO levels, and water retention capacities. Corn stover amendments, by contrast, significantly increased soil CO emissions and microbial populations, and reduced extractable NO. These results indicate that C in fast pyrolysis biochar is stable in soil environments and will not appreciably contribute to nutrient immobilization. PMID:22751053

  9. Extent of pyrolysis impacts on fast pyrolysis biochar properties.

    PubMed

    Brewer, Catherine E; Hu, Yan-Yan; Schmidt-Rohr, Klaus; Loynachan, Thomas E; Laird, David A; Brown, Robert C

    2012-01-01

    A potential concern about the use of fast pyrolysis rather than slow pyrolysis biochars as soil amendments is that they may contain high levels of bioavailable C due to short particle residence times in the reactors, which could reduce the stability of biochar C and cause nutrient immobilization in soils. To investigate this concern, three corn ( L.) stover fast pyrolysis biochars prepared using different reactor conditions were chemically and physically characterized to determine their extent of pyrolysis. These biochars were also incubated in soil to assess their impact on soil CO emissions, nutrient availability, microorganism population growth, and water retention capacity. Elemental analysis and quantitative solid-state C nuclear magnetic resonance spectroscopy showed variation in O functional groups (associated primarily with carbohydrates) and aromatic C, which could be used to define extent of pyrolysis. A 24-wk incubation performed using a sandy soil amended with 0.5 wt% of corn stover biochar showed a small but significant decrease in soil CO emissions and a decrease in the bacteria:fungi ratios with extent of pyrolysis. Relative to the control soil, biochar-amended soils had small increases in CO emissions and extractable nutrients, but similar microorganism populations, extractable NO levels, and water retention capacities. Corn stover amendments, by contrast, significantly increased soil CO emissions and microbial populations, and reduced extractable NO. These results indicate that C in fast pyrolysis biochar is stable in soil environments and will not appreciably contribute to nutrient immobilization.

  10. Fentanyl Sublingual Spray

    MedlinePlus

    ... a solution (liquid) to spray sublingually (under the tongue). It is used as needed to treat breakthrough ... the nozzle into your mouth and under your tongue. Squeeze your fingers and thumb together to spray ...

  11. Mometasone Nasal Spray

    MedlinePlus

    ... allergies. It is also used to treat nasal polyps (swelling of the lining of the nose). Mometasone ... are using mometasone nasal spray to treat nasal polyps, it is usually sprayed in each nostril once ...

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

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

    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.

  13. Remotely controlled spray gun

    NASA Technical Reports Server (NTRS)

    Cunningham, William C. (Inventor)

    1987-01-01

    A remotely controlled spray gun is described in which a nozzle and orifice plate are held in precise axial alignment by an alignment member, which in turn is held in alignment with the general outlet of the spray gun by insert. By this arrangement, the precise repeatability of spray patterns is insured.

  14. Azelastine Nasal Spray

    MedlinePlus

    ... and replace with the pump unit. Prime the delivery system (pump unit) with four sprays or until a fine mist appears. If 3 days or more have elapsed since your last use of the nasal spray, reprime the pump with two sprays or until a fine mist appears.

  15. Cheap carbon sorbents produced from lignite by catalytic pyrolysis

    SciTech Connect

    Kuznetsov, B.N.; Schchipko, M.L.

    1995-12-01

    Some data are presented describing the new technology of carbon sorbent production from powdered lignite in the installation with fluidized bed of catalyst. It was shown the different types of char products with extended pore structure and high sorption ability can be produced from cheap and accessible lignite of Kansk-Achinsk coal pit in pilot installation with fluidized bed of Al-Cu-Cr oxide catalyst or catalytically active slag materials. In comparison with the conventional technologies of pyrolysis the catalytic pyrolysis allows to increase by 3-5 times the process productivity and to decrease significantly the formation of harmful compounds. The latter is accomplished by complete oxidation of gaseous pyrolysis products in the presence of catalysts and by avoiding the formation of pyrolysis tars - the source of cancerogenic compounds. The technology of cheap powdered sorbent production from lignites makes possible to obtain from lignite during the time of pyrolysis only a few seconds char products with porosity up to 0.6 cm{sup 3} /g, and specific surface area more than 400 m{sup 3} /g. Some methods of powdered chars molding into carbon materials with the different shape were proved for producing of firmness sorbents. Cheap carbon sorbents obtained by thermocatalytic pyrolysis can be successfully used in purification of different industrial pollutants as one-time sorbent or as adsorbents of long-term application with periodic regeneration.

  16. Computations of turbulent evaporating sprays

    NASA Technical Reports Server (NTRS)

    Aggarwal, S. K.; Chitre, S.

    1989-01-01

    A computational study of turbulent evaporating sprays is reported. The major focus is to examine the sensitivity of the vaporization behavior of turbulent sprays to the transient liquid-phase processes. Three models considered to represent these processes are the thin skin, infinite diffusion, and diffusion limit models. Favre-averaged equations with k-epsilon-g turbulence model are employed for the gas phase. The Lagrangian approach with a stochastic separated flow method is used for the liquid phase where the effects of gas turbulence on droplet trajectories and interphase transport rates are considered using random-walk computations. Also the variable-property effects are considered in detail. Results indicate that, depending upon the boiling temperature and heat of vaporization of the fuel considered, the vaporization behavior of turbulent sprays may be quite sensitive to the modeling of transient liquid-phase processes. Thus, it is important that for most hydrocarbon fuels these processes be adequately represented in any comprehensive spray computations. The present results also provide further support to the conclusions of earlier studies which have been based on simplified spray configurations.

  17. Concentration-response data on toxicity of pyrolysis gases from some natural and synthetic polymers

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Huttlinger, N. V.

    1978-01-01

    Concentration-response data are presented on the toxic effects of the pyrolysis gases from some natural and synthetic polymers, using the toxicity screening test method developed at the University of San Francisco. The pyrolysis gases from wool, red oak, Douglas fir, polycaprolactam, polyether sulfone, polyaryl sulfone, and polyphenylene sulfide appeared to exhibit the concentration-response relationships commonly encountered in toxicology. Carbon monoxide seemed to be an important toxicant in the pyrolysis gases from red oak, Douglas fir, and polycaprolactam, but did not appear to have been the principal toxicant in the pyrolysis gases from polyether sulfone and polyphenylene sulfide.

  18. Effect of pyrolysis temperature on toxicity of gases from a polyethylene polymer

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Kosola, K. L.

    1978-01-01

    A polyethylene polymer was evaluated for time of toxic effect to occur as the result of exposure to gases generated by pyrolysis at various temperatures, using the toxicity screening test method developed at the University of San Francisco. Times to various animal responses decreased with increasing pyrolysis temperature over the range from 400 C to 800 C. Responses at a pyrolysis temperature of 350 C were more rapid than would be expected from the other data, and may indicate the predominance of different pyrolysis reactions in this particular temperature region.

  19. Pyrolysis and dehalogenation of plastics from waste electrical and electronic equipment (WEEE): a review.

    PubMed

    Yang, Xiaoning; Sun, Lushi; Xiang, Jun; Hu, Song; Su, Sheng

    2013-02-01

    Plastics from waste electrical and electronic equipment (WEEE) have been an important environmental problem because these plastics commonly contain toxic halogenated flame retardants which may cause serious environmental pollution, especially the formation of carcinogenic substances polybrominated dibenzo dioxins/furans (PBDD/Fs), during treat process of these plastics. Pyrolysis has been proposed as a viable processing route for recycling the organic compounds in WEEE plastics into fuels and chemical feedstock. However, dehalogenation procedures are also necessary during treat process, because the oils collected in single pyrolysis process may contain numerous halogenated organic compounds, which would detrimentally impact the reuse of these pyrolysis oils. Currently, dehalogenation has become a significant topic in recycling of WEEE plastics by pyrolysis. In order to fulfill the better resource utilization of the WEEE plastics, the compositions, characteristics and dehalogenation methods during the pyrolysis recycling process of WEEE plastics were reviewed in this paper. Dehalogenation and the decomposition or pyrolysis of WEEE plastics can be carried out simultaneously or successively. It could be 'dehalogenating prior to pyrolysing plastics', 'performing dehalogenation and pyrolysis at the same time' or 'pyrolysing plastics first then upgrading pyrolysis oils'. The first strategy essentially is the two-stage pyrolysis with the release of halogen hydrides at low pyrolysis temperature region which is separate from the decomposition of polymer matrixes, thus obtaining halogenated free oil products. The second strategy is the most common method. Zeolite or other type of catalyst can be used in the pyrolysis process for removing organohalogens. The third strategy separate pyrolysis and dehalogenation of WEEE plastics, which can, to some degree, avoid the problem of oil value decline due to the use of catalyst, but obviously, this strategy may increase the cost of

  20. Pyrolysis and dehalogenation of plastics from waste electrical and electronic equipment (WEEE): a review.

    PubMed

    Yang, Xiaoning; Sun, Lushi; Xiang, Jun; Hu, Song; Su, Sheng

    2013-02-01

    Plastics from waste electrical and electronic equipment (WEEE) have been an important environmental problem because these plastics commonly contain toxic halogenated flame retardants which may cause serious environmental pollution, especially the formation of carcinogenic substances polybrominated dibenzo dioxins/furans (PBDD/Fs), during treat process of these plastics. Pyrolysis has been proposed as a viable processing route for recycling the organic compounds in WEEE plastics into fuels and chemical feedstock. However, dehalogenation procedures are also necessary during treat process, because the oils collected in single pyrolysis process may contain numerous halogenated organic compounds, which would detrimentally impact the reuse of these pyrolysis oils. Currently, dehalogenation has become a significant topic in recycling of WEEE plastics by pyrolysis. In order to fulfill the better resource utilization of the WEEE plastics, the compositions, characteristics and dehalogenation methods during the pyrolysis recycling process of WEEE plastics were reviewed in this paper. Dehalogenation and the decomposition or pyrolysis of WEEE plastics can be carried out simultaneously or successively. It could be 'dehalogenating prior to pyrolysing plastics', 'performing dehalogenation and pyrolysis at the same time' or 'pyrolysing plastics first then upgrading pyrolysis oils'. The first strategy essentially is the two-stage pyrolysis with the release of halogen hydrides at low pyrolysis temperature region which is separate from the decomposition of polymer matrixes, thus obtaining halogenated free oil products. The second strategy is the most common method. Zeolite or other type of catalyst can be used in the pyrolysis process for removing organohalogens. The third strategy separate pyrolysis and dehalogenation of WEEE plastics, which can, to some degree, avoid the problem of oil value decline due to the use of catalyst, but obviously, this strategy may increase the cost of

  1. Characterization of the pyrolysis products of methiopropamine.

    PubMed

    Bouso, Emily D; Gardner, Elizabeth A; O'Brien, John E; Talbot, Brian; Kavanagh, Pierce V

    2014-01-01

    1-(Thien-2-yl)-2-methylaminopropane (methiopropamine, MPA), appeared as a 'legal high' in late 2010. It is structurally similar to methamphetamine, with a thiophene ring replacing the benzene moiety. Methiopropamine reportedly retains the pharmacological properties of amphetamine stimulants, but it does not fall under existing drug laws in the USA and Ireland. The objective of this research was to identify the pyrolysis products formed under conditions that mimic those used by recreational drugs users. Thirteen pyrolysis products were identified and ten were confirmed by comparison to synthesized standards. Methods for synthesizing the standards as well as an alternative method for the synthesis of methiopropamine were developed. The MPA pyrolysis products are formed through N-dealkylation, N-alkylation, N-formylation, β-carbon oxidation, β-carbon oxidation/N-alkylation, amine elimination and carbon-carbon bond cleavage. Two pyrazine isomers also formed. Some of these products have the potential to be psychoactive while others are potentially toxic. PMID:24166818

  2. A comparison of solid sampler methods for the determination of hexamethylene-based isocyanates in spray-painting operations.

    PubMed

    Rudzinski, W E; Yin, J; England, E; Carlton, G; Key-Schwartz, R; Lesage, J

    2001-01-01

    A polyurethane foam sponge impregnated with 1-(2-methoxyphenyl) piperazine in dimethylsulfoxide was mounted in both cassette and inhalable organic monitor samplers and these were then compared with a dual-filter cassette. The samplers were used for the collection of hexamethylene diisocyanate (HDI) monomer and oligomers during actual spray-painting operations. The dual filter cassettes were positioned on a mannequin. The polyurethane foam cassette (PUF CAS) and polyurethane foam inhalable organic monitor (PUF IOM) samplers were positioned on a cart in the same maximum overspray area. Data from this pilot study suggest that there is no significant difference (P < 0.05, n = 6) in the amount of HDI monomer obtained with the PUF IOM sampler when compared with the amount obtained from the dual filter cassette. The data also suggest that the PUF IOM sampler yields a higher amount of HDI oligomer than either the dual filter cassette or the PUF CAS sampler, neither of which exhibited a significant difference (P < 0.05, n = 6) from each other. PMID:11331997

  3. Characterization of sprays

    NASA Technical Reports Server (NTRS)

    Chigier, N.; Mao, C.-P.

    1984-01-01

    It is pointed out that most practical power generation and propulsion systems involve the burning of different types of fuel sprays, taking into account aircraft propulsion, industrial furnaces, boilers, gas turbines, and diesel engines. There has been a lack of data which can serve as a basis for spray model development and validation. A major aim of the present investigation is to fill this gap. Experimental apparatus and techniques for studying the characteristics of fuel sprays are discussed, taking into account two-dimensional still photography, cinematography, holography, a laser diffraction particle sizer, and a laser anemometer. The considered instruments were used in a number of experiments, taking into account three different types of fuel spray. Attention is given to liquid fuel sprays, high pressure pulsed diesel sprays, and coal-water slurry sprays.

  4. Nasal spray flu vaccine (image)

    MedlinePlus

    The flu vaccine can also be administered as a nasal spray instead of the usual injection method. It is an ... 49 who want to be protected from the flu virus. Unlike the regular vaccine, it is a live virus. Therefore, it is ...

  5. Method of creating starch-like ultra-fine rice flour and effect of spray drying on formation of free fatty acid.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice flour from long, medium, and short grain cultivars were processed by passing a 32% rice flour slurry through a microfluidizer at 100 MPa, and spray dryer at three different outlet temperatures, OT (50°C, 80°C, and 115°C). Spray drying conditions were controlled by the flow-rate of the slurry ...

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

    PubMed

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

    2014-10-01

    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.

  7. Imaging and PDA analysis of a GDI spray in the near-nozzle region

    NASA Astrophysics Data System (ADS)

    Wigley, Graham; Goodwin, Martin; Pitcher, Graham; Blondel, Damien

    This paper describes a combined LDA, PDA and imaging analysis of the pressure swirl spray in the near-nozzle region of a GDI injector. This innovative approach in the use of multiple, complementary diagnostics facilitates the interpretation of a complex spray flow field. The LDA and PDA data were ensemble-averaged into time bins to produce comprehensive time-history and spatial profiles of liquid velocity, droplet velocity and size and the sample number. They indicated times at which the spray exhibited seven different characteristics. These were identified as: (a) pre-swirl spray, (b) spray cone develops, (c) spray cone relaxes, (d) maximum velocity in spray cone, (e) fully developed steady state, (f) spray cone collapses and (g) the spray detaches from the nozzle. The most effective method to present the spatial and temporal development of the spray was to superimpose the velocity vector and drop size field plots onto the spray images.

  8. Low-temperature growth and physical investigations of undoped and (In, Co) doped ZnO thin films sprayed on PEI flexible substrate

    NASA Astrophysics Data System (ADS)

    Ben Ameur, S.; Barhoumi, A.; Mimouni, R.; Amlouk, M.; Guermazi, H.

    2015-08-01

    ZnO thin films were deposited on polymer substrate Polyethyerimide (PEI) at 250 °C by spray pyrolysis technique. The effects of different doping elements (Co and In) on physical properties of ZnO thin films were investigated. Thin film characterizations were carried out using X-ray diffraction technique, UV-Vis-NIR spectroscopy, Photoluminescence (PL) spectroscopy and the contact angle measurement method. XRD measurement showed a successful growth of crystalline films on polymer substrate at low temperature by the spray pyrolysis process. XRD patterns revealed that all films consist of single ZnO phase and were well crystallized with preferential orientation towards (1 0 1) direction. Doping by cobalt has effective role in the enhancement of the crystalline quality, increases in the band gap according to Burstein Moss effect. Doping with indium leads rather to the decrease of both crystallinity and optical band gap energy value. Photoluminescence of the films showed UV emission (NBE) and visible emission related to defects. The contact angles were measured to study the effect of various doping elements on the hydrophobicity of the film depending on surface roughness. Results showed strong dependence on the doping element. In fact, doping with cobalt element increases the roughness of ZnO films and reinforces the surface from hydrophilic to hydrophobic (θ > 90°).

  9. Flash Pyrolysis and Fractional Pyrolysis of Oleaginous Biomass in a Fluidized-bed Reactor

    NASA Astrophysics Data System (ADS)

    Urban, Brook

    Thermochemical conversion methods such as pyrolysis have the potential for converting diverse biomass feedstocks into liquid fuels. In particular, bio-oil yields can be maximized by implementing flash pyrolysis to facilitate rapid heat transfer to the solids along with short vapor residence times to minimize secondary degradation of bio-oils. This study first focused on the design and construction of a fluidized-bed flash pyrolysis reactor with a high-efficiency bio-oil recovery unit. Subsequently, the reactor was used to perform flash pyrolysis of soybean pellets to assess the thermochemical conversion of oleaginous biomass feedstocks. The fluidized bed reactor design included a novel feed input mechanism through suction created by flow of carrier gas through a venturi which prevented plugging problems that occur with a more conventional screw feeders. In addition, the uniquely designed batch pyrolysis unit comprised of two tubes of dissimilar diameters. The bottom section consisted of a 1" tube and was connected to a larger 3" tube placed vertically above. At the carrier gas flow rates used in these studies, the feed particles remained fluidized in the smaller diameter tube, but a reduction in carrier gas velocity in the larger diameter "disengagement chamber" prevented the escape of particles into the condensers. The outlet of the reactor was connected to two Allihn condensers followed by an innovative packed-bed dry ice condenser. Due to the high carrier gas flow rates in fluidized bed reactors, bio-oil vapors form dilute aerosols upon cooling which that are difficult to coalesce and recover by traditional heat exchange condensers. The dry ice condenser provided high surface area for inertial impaction of these aerosols and also allowed easy recovery of bio-oils after natural evaporation of the dry ice at the end of the experiments. Single step pyrolysis was performed between 250-610°C with a vapor residence time between 0.3-0.6s. At 550°C or higher, 70% of

  10. Plasma Pyrolysis Assembly Regeneration Evaluation

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

    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.

  11. Catalytic and non-catalytic pyrolysis of biomass in non-inert environments for production of deoxygenated bio-oil and chemicals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fast pyrolysis processes are among the most effective methods for liquefaction of lignocellulosic biomass. Catalytic fast pyrolysis (CFP) over HZSM-5 or other zeolites and/or utilization of reactive atmospheres such as in the non-catalytic Tail Gas Reactive Pyrolysis (TRGP) process, a recent patent...

  12. Microstructural and macroscopic properties of cold sprayed copper coatings

    NASA Astrophysics Data System (ADS)

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

    2003-06-01

    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.

  13. Bear Spray Safety Program

    USGS Publications Warehouse

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

    2009-01-01

    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.

  14. Comparison of apatite-coated titanium prepared by blast coating and flame spray methods--evaluation using simulated body fluid and initial histological study.

    PubMed

    Mano, Takamitsu; Ishikawa, Kunio; Harada, Koji; Umeda, Hirotsugu; Ueyama, Yoshiya

    2011-01-01

    It has previously been demonstrated that apatite may be coated on the surface of titanium (Ti) at room temperature when the titanium is blasted with apatite powder. This method is known as the blast coating (BC) method. In this study, the osteoconductivity and tissue response to Ti implants blast-coated with apatite (BC implants) were evaluated using apatite-coated Ti implants produced using the flame spraying (FS) method (FS implants) and pure Ti implants as a control. Initial evaluation using simulated body fluid demonstrated higher osteoconductivity in BC implants than in FS implants. Therefore, specimens were implanted in rat tibias for 1, 3 and 6 weeks. At one week after implantation, BC implants showed much higher bone contact ratio when compared with FS implants; the bone contact ratio of BC implants was 75.7%, while the FS and pure Ti implants had ratios of 30.8% and 5.5%, respectively. The difference in bone contact ratio between BC and FS implants decreased with implantation time and the ratios were equal after 6 weeks. In conclusion, BC implants show higher osteoconductivity than FS implants, and thus BC implants are beneficial for early fixation of implants to bone tissue. PMID:21778611

  15. Investigation of structural, optical, electrical and dielectric properties of catalytic sprayed hausmannite thin film

    SciTech Connect

    Larbi, T.; Ouni, B.; Boukhachem, A.; Boubaker, K. Amlouk, M.

    2014-12-15

    Hausmannite Mn{sub 3}O{sub 4} thin film have been synthesized using spray pyrolysis method. These films are characterized using X-ray diffraction (XRD), atomic force microscope AFM, UV–vis–NIR spectroscopy and impedance spectroscopy. XRD study confirms the tetragonal structure of the as-deposited films with lattice parameters, a = 5.1822 Å and c = 9.4563 Å and a grain size of about 56 nm. UV–vis–NIR spectroscopy was further used to estimate optical constants such as extinction coefficient, refractive index, band gap and Urbach energy. Moreover, impedance spectroscopy analysis was employed to estimate electrical and dielectrical properties of the sprayed thin films. The activation energy values deduced from DC conductivity and relaxation frequency were almost the same, revealing that the transport phenomena is thermally activated by hopping between localized states. The AC conductivity is found to be proportional to ω{sup s}. The temperature dependence of the AC conductivity and the frequency exponent, s was reasonably well interpreted in terms of the correlated barrier-hopping CBH model. The dielectric properties were sensitive to temperature and frequency. The study of the electrical modulus indicated that the charge carrier was localized. Experimental results concerning optical constants as Urbach energy, dielectric constant, electric modulus and AC and DC conductivity were discussed in terms of the hopping model as suggested by Elliott.

  16. Kinetic energy analysis in time of flight mass spectrometry: application of time of flight methods to clusters and pyrolysis studies in supersonic expansions

    NASA Astrophysics Data System (ADS)

    Riley, John S.; Baer, Tomas

    1994-02-01

    A new experimental technique, based on high resolution time of flight analysis of ions in a molecular beam, is described with the use of several examples. Although the approach used here is based on threshold photoelectron photoion coincidence (TPEPICO), the technique can also be used with pulsed laser photoionization, albeit without the benefit of ion energy selection. The approach is based on the fact that the TOF distribution of parent ions formed from cold neutral molecules are narrow, while product ion TOF distributions are broad due to kinetic energy release. This distinction permits differentiating cluster ions formed by "simple" ionization of the corresponding neutral clusters from similar mass cluster ions formed by dissociative ionization. Results so far obtained indicate that most clusters ionize, even at threshold, via dissociative ionization. The technique is also suitable for obtaining the threshold photoelectron spectra (TPES) of mass selected cold species in the presence of a mixture of warm and cold species as might be encountered in a pyrolysis experiment.

  17. Pyrolysis kinetics of lignocellulosic materials

    SciTech Connect

    Balci, S.; Dogu, T.; Yuecel, H. . Dept. of Chemical Engineering)

    1993-11-01

    Pyrolysis kinetics of almond and hazelnut shells and beech wood were carried out using a thermogravimetric technique. Experiments were repeated for different final pyrolysis temperatures ranging from 300 to 850 C. Approximately 90% of the pyrolysis reactions were completed up to 450 C. The initial values of the activation energy of pyrolysis reaction were found to be around 22 kcal/mol for shells of almond and hazelnut. On the other hand, initial activation energy of beech wood pyrolysis was found as 29.4 kcal/mol. Results indicated that a first-order decomposition in terms of volatile content of the reactant showed good agreement with the data only at the initial stages of the reaction. The reaction rate constant was found to decrease with reaction extent due to the changes in the chemical and physical structure of the solid. Among several models proposed, a model which predicted an increase of activation energy with reaction extent gave the best agreement with the experimental data.

  18. Spray-formed tooling and aluminum strip

    SciTech Connect

    McHugh, K.M.

    1995-11-01

    Spray forming is an advanced materials processing technology that converts a bulk liquid metal to a near-net-shape solid by depositing atomized droplets onto a suitably shaped substrate. By combining rapid solidification processing with product shape control, spray forming can reduce manufacturing costs while improving product quality. De Laval nozzles offer an alternative method to the more conventional spray nozzle designs. Two applications are described: high-volume production of aluminum alloy strip, and the production of specialized tooling, such as injection molds and dies, for rapid prototyping.

  19. Experimental Research of Pyrolysis Gases Cracking on Surface of Charcoal

    NASA Astrophysics Data System (ADS)

    Kosov, Valentin; Kosov, Vladimir; Zaichenko, Victor

    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.

  20. Measuring Spray Droplet Size from Agricultural Nozzles Using Laser Diffraction.

    PubMed

    Fritz, Bradley K; Hoffmann, W Clint

    2016-01-01

    When making an application of any crop protection material such as an herbicide or pesticide, the applicator uses a variety of skills and information to make an application so that the material reaches the target site (i.e., plant). Information critical in this process is the droplet size that a particular spray nozzle, spray pressure, and spray solution combination generates, as droplet size greatly influences product efficacy and how the spray moves through the environment. Researchers and product manufacturers commonly use laser diffraction equipment to measure the spray droplet size in laboratory wind tunnels. The work presented here describes methods used in making spray droplet size measurements with laser diffraction equipment for both ground and aerial application scenarios that can be used to ensure inter- and intra-laboratory precision while minimizing sampling bias associated with laser diffraction systems. Maintaining critical measurement distances and concurrent airflow throughout the testing process is key to this precision. Real time data quality analysis is also critical to preventing excess variation in the data or extraneous inclusion of erroneous data. Some limitations of this method include atypical spray nozzles, spray solutions or application conditions that result in spray streams that do not fully atomize within the measurement distances discussed. Successful adaption of this method can provide a highly efficient method for evaluation of the performance of agrochemical spray application nozzles under a variety of operational settings. Also discussed are potential experimental design considerations that can be included to enhance functionality of the data collected. PMID:27684589

  1. Measuring Spray Droplet Size from Agricultural Nozzles Using Laser Diffraction.

    PubMed

    Fritz, Bradley K; Hoffmann, W Clint

    2016-09-16

    When making an application of any crop protection material such as an herbicide or pesticide, the applicator uses a variety of skills and information to make an application so that the material reaches the target site (i.e., plant). Information critical in this process is the droplet size that a particular spray nozzle, spray pressure, and spray solution combination generates, as droplet size greatly influences product efficacy and how the spray moves through the environment. Researchers and product manufacturers commonly use laser diffraction equipment to measure the spray droplet size in laboratory wind tunnels. The work presented here describes methods used in making spray droplet size measurements with laser diffraction equipment for both ground and aerial application scenarios that can be used to ensure inter- and intra-laboratory precision while minimizing sampling bias associated with laser diffraction systems. Maintaining critical measurement distances and concurrent airflow throughout the testing process is key to this precision. Real time data quality analysis is also critical to preventing excess variation in the data or extraneous inclusion of erroneous data. Some limitations of this method include atypical spray nozzles, spray solutions or application conditions that result in spray streams that do not fully atomize within the measurement distances discussed. Successful adaption of this method can provide a highly efficient method for evaluation of the performance of agrochemical spray application nozzles under a variety of operational settings. Also discussed are potential experimental design considerations that can be included to enhance functionality of the data collected.

  2. LSPRAY-IV: A Lagrangian Spray Module

    NASA Technical Reports Server (NTRS)

    Raju, M. S.

    2012-01-01

    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.

  3. An Optically Accessible Pyrolysis Microreactor

    NASA Astrophysics Data System (ADS)

    Baraban, Joshua H.; David, Donald E.; Ellison, Barney; Daily, John W.

    2016-06-01

    We report an optically accessible pyrolysis micro-reactor suitable for in situ laser spectroscopic measurements. A radiative heating design allows for completely unobstructed views of the micro-reactor along two axes. The maximum temperature demonstrated here is only 1300 K (as opposed to 1700 K for the usual SiC micro-reactor) because of the melting point of fused silica, but alternative transparent materials will allow for higher temperatures. Laser induced fluorescence measurements on nitric oxide are presented as a proof of principle for spectroscopic characterization of pyrolysis conditions. (This work has been published in J. H. Baraban, D. E. David, G. B. Ellison, and J. W. Daily. An Optically Accessible Pyrolysis Micro-Reactor. Review of Scientific Instruments, 87(1):014101, 2016.)

  4. Toxicity of pyrolysis gases from wood

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Huttlinger, N. V.; Oneill, B. A.; Kourtides, D. A.; Parker, J. A.

    1977-01-01

    The toxicity of the pyrolysis gases from nine wood samples was investigated. The samples of hardwoods were aspen poplar, beech, yellow birch, and red oak. The samples of softwoods were western red cedar, Douglas fir, western hemlock, eastern white pine, and southern yellow pine. There was no significant difference between the wood samples under rising temperature conditions, which are intended to simulate a developing fire, or under fixed temperature conditions, which are intended to simulate a fully developed fire. This test method is used to determine whether a material is significantly more toxic than wood under the preflashover conditions of a developing fire.

  5. Cold spray nozzle design

    DOEpatents

    Haynes, Jeffrey D.; Sanders, Stuart A.

    2009-06-09

    A nozzle for use in a cold spray technique is described. The nozzle has a passageway for spraying a powder material, the passageway having a converging section and a diverging section, and at least the diverging section being formed from polybenzimidazole. In one embodiment of the nozzle, the converging section is also formed from polybenzimidazole.

  6. Pyrolysis kinetics of hazelnut husk using thermogravimetric analysis.

    PubMed

    Ceylan, Selim; Topçu, Yıldıray

    2014-03-01

    This study aims at investigating physicochemical properties and pyrolysis kinetics of hazelnut husk, an abundant agricultural waste in Turkey. The physicochemical properties were determined by bomb calorimeter, elemental analysis and FT-IR spectroscopy. Physicochemical analysis results showed that hazelnut husk has a high calorimetric value and high volatile matter content. Pyrolysis experiments were carried out in a thermogravimetric analyzer under inert conditions and operated at different heating rates (5, 10, 20°C/min). Three different kinetic models, the iso-conversional Kissinger-Akahira-Sunose (KAS) and Ozawa-Flynn-Wall (OFW) models and Coats-Redfern method were applied on TGA data of hazelnut husk to calculate the kinetic parameters including activation energy, pre-exponential factor and reaction order. Simulation of hazelnut husk pyrolysis using data obtained from TGA analysis showed good agreement with experimental data. Combining with physicochemical properties, it was concluded that this biomass can become useful source of energy or chemicals. PMID:24508656

  7. Ab initio and RRKM calculations of o-benzyne pyrolysis

    NASA Astrophysics Data System (ADS)

    Deng, Wei-Qiao; Han, Ke-Li; Zhan, Ji-Ping; He, Guo-Zhong

    1998-05-01

    Recently, a new mechanism has been provided in the phenyl pyrolysis, that is, the phenyl dissociation favours the benzyne channel by losing an H atom [H. Wang, M. Frenklach, J. Phys. Chem., 98 (1994) 11465]. In this Letter, the dissociation of o-benzyne has been investigated by means of ab initio theory. The geometries and structures of o-benzyne with its pyrolysis products C 4H 2, C 2H 2 and also the transition state were optimized at the UHF/6-31G* level. The single point energies were refined by B3LYP/6-31G* calculations. The unimolecular rate constants for o-benzyne pyrolysis in different pressures were calculated by the Rice-Ramsperger-Kassel-Marcus (RRKM) method.

  8. An optically accessible pyrolysis microreactor

    NASA Astrophysics Data System (ADS)

    Baraban, J. H.; David, D. E.; Ellison, G. Barney; Daily, J. W.

    2016-01-01

    We report an optically accessible pyrolysis micro-reactor suitable for in situ laser spectroscopic measurements. A radiative heating design allows for completely unobstructed views of the micro-reactor along two axes. The maximum temperature demonstrated here is only 1300 K (as opposed to 1700 K for the usual SiC micro-reactor) because of the melting point of fused silica, but alternative transparent materials will allow for higher temperatures. Laser induced fluorescence measurements on nitric oxide are presented as a proof of principle for spectroscopic characterization of pyrolysis conditions.

  9. Concentration-response data on toxicity of pyrolysis gases from six synthetic polymers

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Huttlinger, N. V.

    1978-01-01

    Concentration-response data are presented on the toxic effects of the pyrolysis gases from six synthetic polymers on Swiss Webster male mice, using a toxicity screening test method. The polymers consisted of one sample each of polycarbonate and polystyrene, and two samples each of polyethylene and acrylonitrile-butadiene-styrene (ABS). All six samples were evaluated using the rising temperature program, and three samples were evaluated using the fixed temperature program. The pyrolysis gases from polycarbonate, polyethylene, and ABS appeared to exhibit the concentration-response relationships commonly encountered in toxicology. The polystyrene sample gave variable results; probably due to poor reproducibility of the essentially anaerobic pyrolysis. Carbon monoxide seemed to be the principal toxicant in the pyrolysis gases from polycarbonate and polyethylene, but did not appear to be the principal toxicant in the pyrolysis gases from ABS.

  10. Thermogravimetric analysis and kinetic study on pyrolysis of representative medical waste composition.

    PubMed

    Deng, Na; Zhang, Yu-feng; Wang, Yan

    2008-01-01

    To obtain detailed information on the pyrolysis characteristics, a thermogravimetric study on the pyrolysis of 14 typical medical waste compositions was carried out in thermogravimetric analysis (TGA) equipment using dynamic techniques in a stream of N2. An index representing pyrolysis reactivity of waste was presented. Kinetic parameters were obtained by Coats-Redfern method and used to model the TG curve. The results showed that: (a) Plastic, protein, cellulosic material, synthetic fibre, and rubber entered pyrolysis process in succession. (b) There was one decomposition stage in the pyrolysis of one-off medical glove, operating glove, cellulosic waste, absorbable catgut suture and adhesive plaster, while other components had two obvious weight loss stages. (c) The obtained apparent activation energy for second stage pyrolysis was comparably higher than that for first stage. (d) Each stage was controlled by only one kinetic mechanism, in which kinetic parameters were constant. (e) The degradation kinetics of medical waste may be affected by special physical and chemical treatment in the product manufacturing process. (f) Among 13 waste samples, the pyrolysis index of cellulosic matter was the highest, which indicated cellulosic matter had strong pyrolysis reactivity. (g) With increasing heating rate, TG curve and DTG peak shifted to high temperatures and main reaction interval of the sample became longer. PMID:17911006

  11. A Comparative study of microwave-induced pyrolysis of lignocellulosic and algal biomass.

    PubMed

    Wang, Nan; Tahmasebi, Arash; Yu, Jianglong; Xu, Jing; Huang, Feng; Mamaeva, Alisa

    2015-08-01

    Microwave (MW) pyrolysis of algal and lignocellulosic biomass samples were studied using a modified domestic oven. The pyrolysis temperature was recorded continuously by inserting a thermocouple into the samples. Temperatures as high as 1170 and 1015°C were achieved for peanut shell and Chlorella vulgaris. The activation energy for MW pyrolysis was calculated by Coats-Redfern method and the values were 221.96 and 214.27kJ/mol for peanut shell and C. vulgaris, respectively. Bio-oil yields reached to 27.7wt.% and 11.0wt.% during pyrolysis of C. vulgaris and peanut shell, respectively. The bio-oil samples from pyrolysis were analyzed by a gas chromatography-mass spectrometry (GC-MS). Bio-oil from lignocellulosic biomass pyrolysis contained more phenolic compounds while that from microalgae pyrolysis contained more nitrogen-containing species. Fourier transform infrared spectroscopy (FTIR) analysis results showed that concentration of OH, CH, CO, OCH3, and CO functional groups in char samples decreased significantly after pyrolysis.

  12. Environmentally compatible spray cement

    SciTech Connect

    Loeschnig, P.

    1995-12-31

    Within the framework of a European research project, Heidelberger Zement developed a quickly setting and hardening binder for shotcrete, called Chronolith S, which avoids the application of setting accelerators. Density and strength of the shotcrete produced with this spray cement correspond to those of an unaccelerated shotcrete. An increased hazard for the heading team and for the environment, which may occur when applying setting accelerators, can be excluded here. Owing to the special setting properties of a spray cement, the process engineering for its manufacturing is of great importance. The treatment of a spray cement as a dry concrete with kiln-dried aggregates is possible without any problems. The use of a naturally damp pre-batched mixture is possible with Chronolith S but requires special process engineering; spray cement and damp aggregate are mixed with one another immediately before entering the spraying machinery.

  13. External characteristics of unsteady spray atomization from a nasal spray device.

    PubMed

    Fung, Man Chiu; Inthavong, Kiao; Yang, William; Lappas, Petros; Tu, Jiyuan

    2013-03-01

    The nasal route presents an enormous opportunity to exploit the highly vascularized respiratory airway for systemic drug delivery to provide more rapid onset of therapy and reduced drug degradation compared with conventional oral routes. The dynamics of atomization at low injection pressure is less known as typical spray atomization studies have focused on industrial applications such as fuel injection that are performed at much higher pressure. An experimental test station was designed in house and an alternative method to characterize the external spray is presented. This involved the use of high-speed camera to capture the temporal development of the spray as it is atomized through actuation of the spray device. An image-processing technique based on edge detection was developed to automate processing through the large number of images captured. The results showed that there are three main phases of spray development (prestable, stable, and poststable) that can be correlated by examining the spray width. A comparison with a human nasal cavity is made to put into perspective the dimensions and geometry that the spray atomization produces. This study aimed to extend the current existing set of data to contribute toward a better understanding in nasal spray drug delivery. PMID:23303644

  14. 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

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

    2012-01-01

    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 S(a) (P < 0.03) and S(q) (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

  15. 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

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

    2012-01-01

    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

  16. Li EXCESS Li4+xTi5-xO12-δ/C COMPOSITE USING SPRAY-DRYING METHOD AND ITS ELECTRODE PROPERTIES

    NASA Astrophysics Data System (ADS)

    Yoshikawa, Daisuke; Suzuki, Norio; Kadoma, Yoshihiro; Ui, Koichi; Kumagai, Naoaki

    2012-03-01

    We have prepared a lithium excess carbon composite material, Li4+xTi5-xO12-δ/C (LTO/C), using various amounts of sucrose as a carbon source by the spray-drying method. The prepared materials were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and elemental analysis. The prepared material had the Li4Ti5O12 phase including 3.9-18.4 wt.% carbon. Transmission electron microscopy images and the selected area diffraction (SAD) pattern showed that the prepared materials consisted of a carbon nanonetwork in the LTO/C composite. The charge-discharge cycling tests were carried out using the R2032 coin-type cell under the following conditions; 1.2-3.0 V, 0.1 C-10 C (1 C = 175 mA g-1), 25°C. Based on the electrochemical results, the electrode performance of the prepared material was improved with increasing amounts of residual carbon, in particular, LTO/C including 6.2 wt.% residual carbon exhibited the best electrode performance of 156 mAh g-1 at 1 C during 50 cyclings when compared to the other materials.

  17. A novel high-performance liquid chromatography-electron spray ionization-mass spectrometry method for simultaneous determination of guggulsterones, piperine and gallic acid in Triphala guggulu.

    PubMed

    Muguli, Ganesh; Vadaparthi, P R Rao; Ramesh, B; Gowda, Vishakante; Paramesh, Rangesh; Jadhav, Atul N; Babu, K Suresh

    2015-05-01

    "Triphalaguggulu" is an important Ayurvedic formulation comprising of Guggulu, that is, Commiphora wightii (Arn.) Bhandari as a base wherein powdered fruits of triphala, that is, Phyllanthus emblica L., Terminalia bellirica (Gaertn.) Roxb and Terminalia chebula Retz, along with powdered fruit of Piper longum L. are compounded. This polyherbal preparation has been strongly recommended in chronic inflammation, piles, and fistula. However, due to the complexity of compound formulation standardization of commercial products is challenging. In the present communication marker-based standardization of "Triphalaguggulu" preparation using gallic acid (for triphala), piperine (for P. longum L.) and guggulsterones (for guggulu) is reported. These compounds of diverse chemistry were successfully separated on a Waters HR-C18 column by isocratic elution with methanol and water (80:20 v/v) as mobile phase at the flow rate of 1.0 mL/min coupled with photodiode array detector. These optimal chromatographic conditions were used for simultaneous quantification of gallic acid, guggulsterones (E and Z) and piperine in commercial samples by high-performance liquid chromatography-electron spray ionization-mass spectrometry and method was validated as per ICH guidelines. PMID:26109777

  18. A novel high-performance liquid chromatography-electron spray ionization-mass spectrometry method for simultaneous determination of guggulsterones, piperine and gallic acid in Triphala guggulu

    PubMed Central

    Muguli, Ganesh; Vadaparthi, P. R. Rao; Ramesh, B.; Gowda, Vishakante; Paramesh, Rangesh; Jadhav, Atul N.; Babu, K. Suresh

    2015-01-01

    “Triphalaguggulu” is an important Ayurvedic formulation comprising of Guggulu, that is, Commiphora wightii (Arn.) Bhandari as a base wherein powdered fruits of triphala, that is, Phyllanthus emblica L., Terminalia bellirica (Gaertn.) Roxb and Terminalia chebula Retz, along with powdered fruit of Piper longum L. are compounded. This polyherbal preparation has been strongly recommended in chronic inflammation, piles, and fistula. However, due to the complexity of compound formulation standardization of commercial products is challenging. In the present communication marker-based standardization of “Triphalaguggulu” preparation using gallic acid (for triphala), piperine (for P. longum L.) and guggulsterones (for guggulu) is reported. These compounds of diverse chemistry were successfully separated on a Waters HR-C18 column by isocratic elution with methanol and water (80:20 v/v) as mobile phase at the flow rate of 1.0 mL/min coupled with photodiode array detector. These optimal chromatographic conditions were used for simultaneous quantification of gallic acid, guggulsterones (E and Z) and piperine in commercial samples by high-performance liquid chromatography-electron spray ionization-mass spectrometry and method was validated as per ICH guidelines. PMID:26109777

  19. Spray Rolling Aluminum Strip

    SciTech Connect

    Lavernia, E.J.; Delplanque, J-P; McHugh, K.M.

    2006-05-10

    Spray forming is a competitive low-cost alternative to ingot metallurgy for manufacturing ferrous and non-ferrous alloy shapes. It produces materials with a reduced number of processing steps, while maintaining materials properties, with the possibility of near-net-shape manufacturing. However, there are several hurdles to large-scale commercial adoption of spray forming: 1) ensuring strip is consistently flat, 2) eliminating porosity, particularly at the deposit/substrate interface, and 3) improving material yield. Through this program, a new strip/sheet casting process, termed spray rolling, has been developed, which is an innovative manufacturing technique to produce aluminum net-shape products. Spray rolling combines the benefits of twin-roll casting and conventional spray forming, showing a promising potential to overcome the above hurdles associated with spray forming. Spray rolling requires less energy and generates less scrap than conventional processes and, consequently, enables the development of materials with lower environmental impacts in both processing and final products. Spray Rolling was developed as a collaborative project between the University of California-Davis, the Colorado School of Mines, the Idaho National Engineering and Environmental Laboratory, and an industry team. The following objectives of this project were achieved: (1) Demonstration of the feasibility of the spray rolling process at the bench-scale level and evaluation of the materials properties of spray rolled aluminum strip alloys; and (2) Demonstration of 2X scalability of the process and documentation of technical hurdles to further scale up and initiate technology transfer to industry for eventual commercialization of the process.

  20. A simplified model of aerosol removal by containment sprays

    SciTech Connect

    Powers, D.A. ); Burson, S.B. . Div. of Safety Issue Resolution)

    1993-06-01

    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.

  1. Coal structure vs flash pyrolysis products

    SciTech Connect

    Calkins, W.H.

    1983-01-01

    The fast pyrolysis of coal produces tar, char and a range of low molecular weight gases in various proportions and amounts depending on the pyrolysis conditions (temperature, pressure) and the coal being pyrolyzed. Much research effort has been devoted to study of the reaction kinetics and effect of process variables, attempting thereby to elucidate the pyrolysis mechanism. Less effort has been focused on coal chemical structure and its relationship to the pyrolysis reactions and pyrolysis products. It was to attempt to better understand coal structure and its influence on pyrolysis products and pyrolysis mechanisms that this project was undertaken. This paper reports only on that portion of the work concerned with the aliphatic hydrocarbon products and particularly the light olefins. (7 tables, 12 figures, 16 refs.)

  2. Initial Stages of Pyrolysis of Polyethylene

    NASA Astrophysics Data System (ADS)

    Popov, Konstantin V.

    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

  3. Corn and sorghum performance are affected by irrigation application method: SDI versus Mid-elevation spray irrigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It is known that irrigation application method can impact crop water use and water use efficiency, but the mechanisms involved are incompletely understood, particularly in terms of the water and energy balances during the growing season from pre-irrigation through planting, early growth and yield de...

  4. Corn and sorghum performance affected by irrigation application method:SDI versus mid-elevation spray irrigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It is known that irrigation application method can impact crop water use and water use efficiency, but the mechanisms involved are incompletely understood, particularly in terms of the water and energy balances during the growing season from pre-irrigation through planting, early growth and yield de...

  5. Corn and sorghum performance are affected by irrigation application method: SDI versus mid-elevation spray irrigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irrigation application method can impact crop water use and water use efficiency (WUE), but the mechanisms involved are incompletely understood, particularly in terms of the water and energy balances during the growing season from pre-irrigation through the planting, early growth and yield developme...

  6. Vacuum pyrolysis of used tires

    SciTech Connect

    Roy, C.; Darmstadt, H.; Benallal, B.; Chaala, A.; Schwerdtfeger, A.E.

    1995-11-01

    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.

  7. Uniform-droplet spray forming

    SciTech Connect

    Blue, C.A.; Sikka, V.K.; Chun, Jung-Hoon; Ando, T.

    1997-04-01

    The uniform-droplet process is a new method of liquid-metal atomization that results in single droplets that can be used to produce mono-size powders or sprayed-on to substrates to produce near-net shapes with tailored microstructure. The mono-sized powder-production capability of the uniform-droplet process also has the potential of permitting engineered powder blends to produce components of controlled porosity. Metal and alloy powders are commercially produced by at least three different methods: gas atomization, water atomization, and rotating disk. All three methods produce powders of a broad range in size with a very small yield of fine powders with single-sized droplets that can be used to produce mono-size powders or sprayed-on substrates to produce near-net shapes with tailored microstructures. The economical analysis has shown the process to have the potential of reducing capital cost by 50% and operating cost by 37.5% when applied to powder making. For the spray-forming process, a 25% savings is expected in both the capital and operating costs. The project is jointly carried out at Massachusetts Institute of Technology (MIT), Tuffs University, and Oak Ridge National Laboratory (ORNL). Preliminary interactions with both finished parts and powder producers have shown a strong interest in the uniform-droplet process. Systematic studies are being conducted to optimize the process parameters, understand the solidification of droplets and spray deposits, and develop a uniform-droplet-system (UDS) apparatus appropriate for processing engineering alloys.

  8. 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...

  9. Large volume water sprays for dispersing warm fogs

    NASA Astrophysics Data System (ADS)

    Keller, V. W.; Anderson, B. J.; Burns, R. A.; Lala, G. G.; Meyer, M. B.

    A new method for dispersing of warm fogs which impede visibility and alter schedules is described. The method uses large volume recycled water sprays to create curtains of falling drops through which the fog is processed by the ambient wind and spray-induced air flow; the fog droplets are removed by coalescence/rainout. The efficiency of this fog droplet removal process depends on the size spectra of the spray drops and optimum spray drop size is calculated as between 0.3-1.0 mm in diameter. Water spray tests were conducted in order to determine the drop size spectra and temperature response of sprays produced by commercially available fire-fighting nozzles, and nozzle array tests were utilized to study air flow patterns and the thermal properties of the overall system. The initial test data reveal that the fog-dispersal procedure is effective.

  10. Pyrolysis-combustion 14C dating of soil organic matter

    USGS Publications Warehouse

    Wang, Hongfang; Hackley, Keith C.; Panno, S.V.; Coleman, D.D.; Liu, J.C.-L.; Brown, J.

    2003-01-01

    Radiocarbon (14C) dating of total soil organic matter (SOM) often yields results inconsistent with the stratigraphic sequence. The onerous chemical extractions for SOM fractions do not always produce satisfactory 14C dates. In an effort to develop an alternative method, the pyrolysis-combustion technique was investigated to partition SOM into pyrolysis volatile (Py-V) and pyrolysis residue (Py-R) fractions. The Py-V fractions obtained from a thick glacigenic loess succession in Illinois yielded 14C dates much younger but more reasonable than the counterpart Py-R fractions for the soil residence time. Carbon isotopic composition (??13C) was heavier in the Py-V fractions, suggesting a greater abundance of carbohydrate- and protein-related constituents, and ??13C was lighter in the Py-R fractions, suggesting more lignin- and lipid-related constituents. The combination of 14C dates and ??13C values indicates that the Py-V fractions are less biodegradation resistant and the Py-R fractions are more biodegradation resistant. The pyrolysis-combustion method provides a less cumbersome approach for 14C dating of SOM fractions. With further study, this method may become a useful tool for analyzing unlithified terrestrial sediments when macrofossils are absent. ?? 2003 University of Washington. Published by Elsevier Inc. All rights reserved.

  11. High mass throughput particle generation using multiple nozzle spraying

    DOEpatents

    Pui, David Y. H.; Chen, Da-Ren

    2015-06-09

    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.

  12. High mass throughput particle generation using multiple nozzle spraying

    DOEpatents

    Pui, David Y.H.; Chen, Da-Ren

    2004-07-20

    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.

  13. High mass throughput particle generation using multiple nozzle spraying

    DOEpatents

    Pui, David Y. H.; Chen, Da-Ren

    2009-03-03

    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.

  14. Pyrolysis Strategies for Effective Utilization of Lignocellulosic and Algal Biomass

    NASA Astrophysics Data System (ADS)

    Maddi, Balakrishna

    Pyrolysis is a processing technique involving thermal degradation of biomass in the absence of oxygen. The bio-oils obtained following the condensation of the pyrolysis vapors form a convenient starting point for valorizing the major components of lignocellulosic as well as algal biomass feed stocks for the production of fuels and value-added chemicals. Pyrolysis can be implemented on whole biomass or on residues left behind following standard fractionation methods. Microalgae and oil seeds predominantly consist of protein, carbohydrate and triglycerides, whereas lignocellulose is composed of carbohydrates (cellulose and hemicellulose) and lignin. The differences in the major components of these two types of biomass will necessitate different pyrolysis strategies to derive the optimal benefits from the resulting bio-oils. In this thesis, novel pyrolysis strategies were developed that enable efficient utilization of the bio-oils (and/or their vapors) from lignocellulose, algae, as well as oil seed feed stocks. With lignocellulosic feed stocks, pyrolysis of whole biomass as well as the lignin residue left behind following well-established pretreatment and saccharification (i.e., depolymerization of cellulose and hemicellulose to their monomeric-sugars) of the biomass was studied with and without catalysts. Following this, pyrolysis of (lipid-deficient) algae and lignocellulosic feed stocks, under similar reactor conditions, was performed for comparison of product (bio-oil, gas and bio-char) yields and composition. In spite of major differences in component bio-polymers, feedstock properties relevant to thermo-chemical conversions, such as overall C, H and O-content, C/O and H/C molar ratio as well as calorific values, were found to be similar for algae and lignocellulosic material. Bio-oil yields from algae and some lignocellulosic materials were similar; however, algal bio-oils were compositionally different and contained several N-compounds (most likely from

  15. Nicotine Nasal Spray

    MedlinePlus

    ... program, which may include support groups, counseling, or specific behavior change techniques. Nicotine nasal spray is in ... bottles at room temperature and away from excess heat and moisture (not in the bathroom). Discard used ...

  16. Triamcinolone Nasal Spray

    MedlinePlus

    Nasacort® Allergy 24HR ... watery eyes caused by hay fever or other allergies. Triamcinolone nasal spray should not be used to ... the release of certain natural substances that cause allergy symptoms.

  17. Naloxone Nasal Spray

    MedlinePlus

    ... is used along with emergency medical treatment to reverse the life-threatening effects of a known or ... this date passes.Naloxone nasal spray may not reverse the effects of certain opiates such as buprenorphine ( ...

  18. Beclomethasone Nasal Spray

    MedlinePlus

    ... the lining of the nose) after nasal polyp removal surgery. Beclomethasone nasal spray should not be used ... room temperature and away from excess heat and moisture (not in the bathroom).Unneeded medications should be ...

  19. Fentanyl Nasal Spray

    MedlinePlus

    ... older who are taking regularly scheduled doses of another narcotic (opiate) pain medication, and who are tolerant ( ... spray, your doctor may tell you to use another pain medication to relieve that pain, and may ...

  20. Nasal corticosteroid sprays

    MedlinePlus

    ... Allergic rhinitis symptoms , such as congestion, runny nose, sneezing, itching, or swelling of the nasal passageway Nasal ... Repeat these steps for the other nostril. Avoid sneezing or blowing your nose right after spraying.