WorldWideScience

Sample records for pyrolysis doping influence

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

    International Nuclear Information System (INIS)

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

    2013-01-01

    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 0.8 Gd 0.2 O 1.9−x , or CGO) thin films, deposited by spray pyrolysis (SP). Spray pyrolysis is a high thermal deposition method that combines material deposition and heat treatment. This combination is advantageous since the post-deposition heat treatment step is not necessary. However, stresses are solidified in the coating during the deposition, which may lead to the initiation of a crack in the coating. The aim of this work was to achieve thin, dense, and continuous CGO coatings, which may be used as gas separation membranes and as a solid state electrochemical interfaces. Dense, flat, low-defect substrates such as silica slides, silicon mono crystal wafers, and porous substrates were used as substrates in this work. Cerium ammonium nitrate and gadolinium acetylacetonate were dissolved in ethanol and butyl carbitol to form a precursor solution that was sprayed on the heated substrates. Process parameters such as solvent composition, deposition rate and different heating regimes were analyzed. The microstructure was analyzed by secondary electron microscopy (SEM) and was found that thin, dense, and defect-free films could be produced on dense and porous substrates. The results obtained show that it is possible to obtain a CGO dense film deposited by spray pyrolysis. X-ray diffraction

  2. Influences of Pr and Ta doping concentration on the characteristic features of FTO thin film deposited by spray pyrolysis

    International Nuclear Information System (INIS)

    Turgut, Güven; Koçyiğit, Adem; Sönmez, Erdal

    2015-01-01

    The Pr and Ta separately doped FTO (10 at.% F incorporated SnO 2 ) films are fabricated via spray pyrolysis. The microstructural, topographic, optical, and electrical features of fluorine-doped TO (FTO) films are investigated as functions of Pr and Ta dopant concentrations. The x-ray diffraction (XRD) measurements reveal that all deposited films show polycrystalline tin oxide crystal property. FTO film has (200) preferential orientation, but this orientation changes to (211) direction with Pr and Ta doping ratio increasing. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) analyses show that all films have uniform and homogenous nanoparticle distributions. Furthermore, morphologies of the films depend on the ratio between Pr and Ta dopants. From ultraviolet-visible (UV-Vis) spectrophotometer measurements, it is shown that the transmittance value of FTO film decreases with Pr and Ta doping elements increasing. The band gap value of FTO film increases only at 1 at.% Ta doping level, it drops off with Pr and Ta doping ratio increasing at other doped FTO films. The electrical measurements indicate that the sheet resistance value of FTO film initially decreases with Pr and Ta doping ratio decreasing and then it increases with Pr and Ta doping ratio increasing. The highest value of figure of merit is obtained for 1 at.% Ta- and Pr-doped FTO film. These results suggest that Pr- and Ta-doped FTO films may be appealing candidates for TCO applications. (paper)

  3. Influence of Y doping concentration on the properties of nanostructured MxZn1-xO (M=Y) thin film deposited by nebulizer spray pyrolysis technique

    Science.gov (United States)

    Mariappan, R.; Ponnuswamy, V.; Chandra Bose, A.; Suresh, R.; Ragavendar, M.

    2014-09-01

    Yttrium doped Zinc Oxide (YxZn1-xO) thin films deposited at a substrate temperature 400 °C. The effect of substrate temperature on the structural, surface morphology, compositional, optical and electrical properties of YxZn1-xO thin films was studied. X-ray diffraction studies show that all films are polycrystalline in nature with hexagonal crystal structure having highly textured (002) plane parallel to the surface of the substrate. The structural parameters, such as lattice constants (a and c), crystallite size (D), dislocation density (δ), microstrain (σ) and texture coefficient were calculated for different yttrium doping concentrations (x). High resolution scanning electron microscopy measurements reveal that the surface morphology of the films change from platelet like grains to hexagonal structure with grain size increase due to the yttrium doping. Energy dispersive spectroscopy confirms the presence of Y, Zn and O elements in the films prepared. Optical studies showed that all samples have a strong optical transmittance higher than 70% in the visible range. A slight shift of the absorption edge towards the large wavelengths was observed as the Y doping concentration increased. This result shows that the band gap is slightly decreased from 3.10 to 2.05 eV with increase of the yttrium doping concentrations (up to 7.5%) and then slightly increased. Room temperature PL measurements were done and the band-to-band emission energies of films were determined and reported. The complex impedance of the 10%Y doped ZnO film shows two distinguished semicircles and the diameter of the arcs got decreased in diameter as the temperature increases from 70 to 175 °C.

  4. Nitrogen-doping effects on the growth, structure and electrical performance of carbon nanotubes obtained by spray pyrolysis method

    Energy Technology Data Exchange (ETDEWEB)

    Ionescu, Mihnea Ioan; Zhang Yong; Li Ruying [Department of Mechanical and Materials Engineering, University of Western Ontario, London, ON N6A 5B9 (Canada); Abou-Rachid, Hakima [Defense Research and Development Canada - Valcartier, 2459 Boulevard PieXI Nord, Quebec, QC G3J 1X5 (Canada); Sun Xueliang, E-mail: xsun@eng.uwo.ca [Department of Mechanical and Materials Engineering, University of Western Ontario, London, ON N6A 5B9 (Canada)

    2012-03-01

    Vertically aligned nitrogen-doped carbon nanotubes (CNTs) with modulated nitrogen content have been synthesized in a large scale by using spray pyrolysis chemical vapor deposition technique. The effects of nitrogen doping on the growth, structure and electrical performance of carbon nanotubes have been systematically examined. Field emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and Raman techniques have been employed to characterize the morphology, composition, and vibrational properties of nanotubes. The results indicate that the nitrogen incorporation significantly influences the growth rate, morphology, size and structure of nanotubes. Electrical measurement investigation of the nanotubes indicates that the change in electrical resistance increases with temperature and pressure as the nitrogen concentration increases inside the tubes. This work presents a versatile, safe, and easy way to scale up route of growing carbon nanotubes with controlled nitrogen content and modulated structure, and may provide an insight in developing various nitrogen-doped carbon-based nanodevices.

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

    International Nuclear Information System (INIS)

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

    2010-01-01

    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 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 2 nanoparticles is reduced by more than three orders compared with the pure SnO 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 2 O 3 .

  6. Electrically active, doped monocrystalline silicon nanoparticles produced by hot wire thermal catalytic pyrolysis

    CSIR Research Space (South Africa)

    Scriba, MR

    2011-05-01

    Full Text Available Doped silicon nanoparticles have successfully been produced by hot wire thermal catalytic pyrolysis at 40 mbar and a filament temperature of 1800 °C, using a mixture of silane and diborane or phosphine. All particles are monocrystalline with shapes...

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

    Energy Technology Data Exchange (ETDEWEB)

    Sadananda Kumar, N., E-mail: sadanthara@gmail.com; Bangera, Kasturi V.; Shivakumar, G. K. [National Institute of Technology Karnataka, Surathkal, Thin Films Laboratory, Department of Physics (India)

    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}.

  8. Probing the doping mechanisms and electrical properties of Al, Ga and In doped ZnO prepared by spray pyrolysis

    KAUST Repository

    Maller, Robert

    2016-05-24

    The measured structural, optical and electrical properties of Al, Ga and In doped ZnO films deposited using spray pyrolysis are reported over the doping range 0.1 - 3 atomic percent (at. %). Over the entire doping series highly transparent, polycrystalline thin films are prepared. Using the AC Hall effect we probe the electronic properties of our doped films separating the impact of doping on the measured charge carrier concentrations and Hall mobility, with an emphasis on the low doping, < 1 at. %, range. In this doping range highly resistive films are formed and we highlight AC Hall as a reliable and highly reproducible technique for analysing the doping mechanism. The implementation of a simple, post-deposition heat treatment of our AZO films creates typical films with charge carrier concentrations exceeding > 1019 cm-3 and electron mobilities over 10 cm2/Vs. We describe in detail the nature of the defect chemistry and the role of intrinsic defects, particularly traps, and show that despite significant variations in dopant species and grain boundary concentrations that the defect chemistry dominates the electrical characteristics.

  9. Probing the doping mechanisms and electrical properties of Al, Ga and In doped ZnO prepared by spray pyrolysis

    KAUST Repository

    Maller, Robert; Porte, Yoann; Alshareef, Husam N.; McLachlan, Martyn

    2016-01-01

    The measured structural, optical and electrical properties of Al, Ga and In doped ZnO films deposited using spray pyrolysis are reported over the doping range 0.1 - 3 atomic percent (at. %). Over the entire doping series highly transparent, polycrystalline thin films are prepared. Using the AC Hall effect we probe the electronic properties of our doped films separating the impact of doping on the measured charge carrier concentrations and Hall mobility, with an emphasis on the low doping, < 1 at. %, range. In this doping range highly resistive films are formed and we highlight AC Hall as a reliable and highly reproducible technique for analysing the doping mechanism. The implementation of a simple, post-deposition heat treatment of our AZO films creates typical films with charge carrier concentrations exceeding > 1019 cm-3 and electron mobilities over 10 cm2/Vs. We describe in detail the nature of the defect chemistry and the role of intrinsic defects, particularly traps, and show that despite significant variations in dopant species and grain boundary concentrations that the defect chemistry dominates the electrical characteristics.

  10. Spray pyrolysis of doped-ceria barrier layers for solid oxide fuel cells

    DEFF Research Database (Denmark)

    Szymczewska, Dagmara; Chrzan, Aleksander; Karczewski, Jakub

    2017-01-01

    Gadolinium doped ceria (Ce0.8Gd0.2O2 − x-CGO) layer fabricated by spray pyrolysis is investigated as the diffusion barrier for solid oxide fuel cell. It is deposited between the La0.6Sr0.4FeO3 − δ cathode and the yttria stabilized zirconia electrolyte to mitigate harmful interdiffusion...

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

    Energy Technology Data Exchange (ETDEWEB)

    Karakaya, Seniye, E-mail: seniyek@ogu.edu.tr; Ozbas, Omer

    2015-02-15

    Highlights: • Nanostructure undoped and boron doped ZnO films were deposited by USP technique. • Influences of doping on the surface and optical properties of the ZnO films were investigated. • XRD spectra of the films exhibited a variation in crystalline quality depending on the B content. - Abstract: 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 (SnO{sub 2}) 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

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

    International Nuclear Information System (INIS)

    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 cm"2 V"−"1 s"−"1 and 2.8×10"1"7 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.

  13. Investigation on the effect of Zr doping in ZnO thin films by spray pyrolysis

    International Nuclear Information System (INIS)

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

    2011-01-01

    Zirconium doped zinc oxide thin films with enhanced optical transparency were prepared on Corning 1737 glass substrates at the substrate temperature of 400 o C by spray pyrolysis method for various doping concentrations of zirconium (IV) chloride in the spray solution. The X-ray diffraction studies reveal that the films exhibit hexagonal crystal structure with polycrystalline grains oriented along (0 0 2) direction. The crystalline quality of the films is found to be deteriorating with the increase of doping concentration and acquires amorphous state for higher concentration of 8 at.% in precursor solution. The average transmittance for 5 at.% (solution) zirconium doped ZnO film is significantly increased to ∼92% in the visible region of 500-800 nm. The room temperature photoluminescence (PL) spectra of films show a band edge between 3.41 and 3.2 eV and strong blue emission at 2.8 eV irrespective of doping concentration and however intensity increases consistently with doping levels. The vacuum annealing at 400 o C reduced the resistivity of the films significantly due to the coalescence of grains and the lowest resistivity of 2 x 10 -3 Ω cm is observed for 3 at.% (solution) Zr doped ZnO films which envisages that it is a good candidate for stable TCO material.

  14. Influence of Temperature on Pyrolysis of Biomass

    Science.gov (United States)

    Kumar, S.; Pattnaik, D.; Bhuyan, S. K.; Mishra, S. C.

    2018-03-01

    The Antimicrobial and anti-inflammatory nature of the castor oil is used for the treatment of constipation and also used to clean the intestine before a surgical treatment. The growing demand castor oil due to its cheaper price and have much demand to grow hairs faster which give proteins to hair and increases the life span of hair and increases the hair capacity and provide hair smoothness because it has high ricinoleic ratio which is beneficial for skin and hair. The main objective of this paper is by observing its usefulness and the current aim for the research work is to produce bio-char/carbon compounds and extraction of higher carbon content. The castor leaves are collected and dried in the sun light to get it moisture free and proximate analysis is studied that reveals 14% of fixed amount of carbon. The dried leaves of castor plant are pyrolized at different temperature ranges 250°C, 350 °C, 450°C, 600°C and 900°C. The pyrolised specimens were studied by Fourier-transform infrared spectroscopy analysis which shows the transformation and formation of several bonds including carbon bonds which are affected during carbonization. Scanning electron microscope and energy dispersive x-ray spectroscopy have been studied on pyrolised specimen to get microstructures elements in the bio-char. The parameter called carbon/oxygen ration gives the advantage of char in the agricultural land for fertility motive and discrepancy of carbon and oxygen contents have been analysed. It has been found that carbon/oxygen ration increased along increment in Pyrolysis tempt. Up to 500°C and therefore along moreover increment in tempt. Beyond 500°C there is a decrement trend has been found.

  15. Synthesis and characterization of cobalt doped nickel oxide thin films by spray pyrolysis method

    Science.gov (United States)

    Sathisha, D.; Naik, K. Gopalakrishna

    2018-05-01

    Cobalt (Co) doped nickel oxide (NiO) thin films were deposited on glass substrates at a temperature of about 400 °C by spray pyrolysis method. The effect of Co doping concentration on structural, optical and compositional properties of NiO thin films was investigated. X-ray diffraction result shows that the deposited thin films are polycrystalline in nature. Surface morphologies of the deposited thin films were observed by FESEM and AFM. EDS spectra showed the incorporation of Co dopants in NiO thin films. Optical properties of the grown thin films were characterized by UV-visible spectroscopy. It was found that the optical band gap energy and transmittance of the films decrease with increasing Co doping concentration.

  16. Synthesis and characterization of Fe doped cadmium selenide thin films by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Abhijit A., E-mail: aay_physics@yahoo.co.in [Thin Film Physics Laboratory, Department of Physics, Electronics and Photonics, Rajarshi Shahu Mahavidyalaya, Latur 413 512, Maharashtra (India)

    2012-12-05

    Highlights: Black-Right-Pointing-Pointer Simple and inexpensive method to dope trivalent Fe in CdSe thin films. Black-Right-Pointing-Pointer Fe doped CdSe thin films are highly photosensitive. Black-Right-Pointing-Pointer AFM analysis shows uniform deposition of film over the entire substrate surface. Black-Right-Pointing-Pointer The band gap energy decreases from 1.74 to 1.65 eV with Fe doping. Black-Right-Pointing-Pointer Film resistivity decreases to 6.76 Multiplication-Sign 10{sup 4} {Omega}-cm with Fe doping in CdSe thin films. - Abstract: Undoped and Fe doped CdSe thin films have been deposited onto the amorphous and fluorine doped tin oxide coated glass substrates by spray pyrolysis. The Fe doping concentration has been optimized by photoelectrochemical (PEC) characterization technique. The structural, surface morphological, compositional, optical and electrical properties of undoped and Fe doped CdSe thin films have been studied. X-ray diffraction study reveals that the as deposited CdSe films possess hexagonal crystal structure with preferential orientation along (1 0 0) plane. AFM analysis shows uniform deposition of the film over the entire substrate surface with minimum surface roughness of 7.90 nm. Direct allowed type of transition with band gap decreasing from 1.74 to 1.65 eV with Fe doping has been observed. The activation energy of the films has been found to be in the range of 0.14-0.19 eV at low temperature and 0.27-0.44 eV at high temperature. Semi-conducting behavior has been observed from resistivity measurements. The thermoelectric power measurements reveal that the films are of n type.

  17. Influence of Pyrolysis Parameters on the Performance of CMSM

    Directory of Open Access Journals (Sweden)

    Marta C. Campo

    2009-01-01

    Full Text Available Carbon hollow fiber membranes have been prepared by pyrolysis of a P84/S-PEEK blend. Proximate analysis of the precursor was performed using thermogravimetry (TGA, and a carbon yield of approximately 40% can be obtained. This study aimed at understanding the influence of pyrolysis parameters—end temperature, quenching effect, and soaking time—on the membrane properties. Permeation experiments were performed with N2, He, and CO2. Scanning electron microscopy (SEM has been done for all carbon hollow fibers. The highest permeances were obtained for the membrane submitted to an end temperature of 750°C and the highest ideal selectivities for an end temperature of 700°C. In both cases, the membranes were quenched to room temperature.

  18. Suspension Combustion of Wood: Influence of Pyrolysis Conditions on Char Yield, Morphology, and Reactivity

    DEFF Research Database (Denmark)

    Dall'Ora, Michelangelo; Jensen, Peter Arendt; Jensen, Anker Degn

    2008-01-01

    Chars from pine and beech wood were produced by fast pyrolysis in an entrained flow reactor and by slow pyrolysis in a thermogravimetric analyzer. The influence of pyrolysis temperature, heating rate and particle size on char yield and morphology was investigated. The applied pyrolysis temperature...... varied in the range 673−1673 K for slow pyrolysis and between 873 and 1573 K for fast pyrolysis. The chars were oxidized in a thermogravimetric analyzer and the mass loss data were used to determine char oxidation reactivity. Char yield from fast pyrolysis (104−105 K/s) was as low as 1 to 6% on a dry ash......, char oxidation reactivity decreased as pyrolysis temperature increased. The amount and composition of the ash forming matter of the wood fuels seems to play an important role in determining the differences in char yield, morphology and reactivity....

  19. Spectroscopic and luminescent properties of Co2+ doped tin oxide thin films by spray pyrolysis

    Directory of Open Access Journals (Sweden)

    K. Durga Venkata Prasad

    2016-07-01

    Full Text Available The wide variety of electronic and chemical properties of metal oxides makes them exciting materials for basic research and for technological applications alike. Oxides span a wide range of electrical properties from wide band-gap insulators to metallic and superconducting. Tin oxide belongs to a class of materials called Transparent Conducting Oxides (TCO which constitutes an important component for optoelectronic applications. Co2+ doped tin oxide thin films were prepared by chemical spray pyrolysis synthesis and characterized by powder X-ray diffraction, SEM, TEM, FT-IR, optical, EPR and PL techniques to collect the information about the crystal structure, coordination/local site symmetry of doped Co2+ ions in the host lattice and the luminescent properties of the prepared sample. Powder XRD data revealed that the crystal structure belongs to tetragonal rutile phase and its lattice cell parameters are evaluated. The average crystallite size was estimated to be 26 nm. The morphology of prepared sample was analyzed by using SEM and TEM studies. Functional groups of the prepared sample were observed in the FT-IR spectrum. Optical absorption and EPR studies have shown that on doping, Co2+ ions enter in the host lattice as octahedral site symmetry. PL studies of Co2+ doped SnO2 thin films exhibit blue and yellow emission bands. CIE chromaticity coordinates were also calculated from emission spectrum of Co2+ doped SnO2 thin films.

  20. An investigation on the In doping of ZnO thin films by spray pyrolysis

    Science.gov (United States)

    Mahesh, Devika; Kumar, M. C. Santhosh

    2018-04-01

    Indium doped zinc oxide (IGZO)thin films are gaining much interest owing to its commercial application as transparent conductive oxide thin films. In the current study thin films indium doped ZnO thin films have been deposited on glass substrates by chemical spray pyrolysis technique with an indium concentration of 1, 2.5 and 4% in Zinc source. The films show a peak shift in the X-Ray Diffraction patterns with varying indium doping concentration. The (101) peak was enhanced for the 2.5 % indium doped films and variation in grain size with the different doping levels was studied. The as-deposited films are uniform and shown high transparency (>90%) in the visible region. Average thicknesses of films are found to be 800nm, calculated using the envelope method. The film with 2.5 % of indium content was found to be highly conducting than the rest, since for the lower and higher concentrations the conductivity was possibly halted by the limit in carrier concentration and indium segregation in the grain boundaries respectively. The enhancement of mobility and carrier concentration was clearly seen in the optimum films.

  1. Gas Sensing of Fluorine Doped Tin Oxide Thin Films Prepared by Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    A. A. YADAV

    2008-05-01

    Full Text Available Fluorine doped tin oxide (F: SnO2 films have been prepared onto the amorphous glass substrates by a spray pyrolysis. XRD studies reveal that the material deposited is polycrystalline SnO2 and have tetragonal structure. It is observed that films are highly orientated along (200 direction. The direct optical band gap energy for the F: SnO2 films are found to be 4.15 eV. Gas sensing properties of the sensor were checked against combustible gases like H2, CO2 CO, C3H8, CH4.The H2 sensitivity of the F-doped SnO2 sensor was found to be increased. The increase in the sensitivity is discussed in terms of increased resistivity and reduced permeation of gaseous oxygen into the underlying sensing layer due to the surface modification of the sensor.

  2. Catalytic upgrading of sugar fractions from pyrolysis oils in supercritical mono-alcohols over Cu doped porous metal oxide

    NARCIS (Netherlands)

    Yin, Wang; Venderbosch, Hendrikus; Bottari, Giovanni; Krawzcyk, Krzysztof K.; Barta, Katalin; Heeres, Hero Jan

    In this work, we report on the catalytic valorization of sugar fractions, obtained by aqueous phase extraction of fast pyrolysis oils, in supercritical methanol (scMeOH) and ethanol (scEtOH) over a copper doped porous metal oxide (Cu-PMO). The product mixtures obtained are, in principle, suitable

  3. Highly doped ZnO films deposited by spray-pyrolysis. Design parameters for optoelectronic applications

    Energy Technology Data Exchange (ETDEWEB)

    Garcés, F.A., E-mail: felipe.garces@santafe-conicet.gov.ar [Instituto de Física del Litoral (UNL-CONICET), Güemes 3450, Santa Fe S3000GLN (Argentina); Budini, N. [Instituto de Física del Litoral (UNL-CONICET), Güemes 3450, Santa Fe S3000GLN (Argentina); Schmidt, J.A.; Arce, R.D. [Instituto de Física del Litoral (UNL-CONICET), Güemes 3450, Santa Fe S3000GLN (Argentina); Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santiago del Estero 2829, Santa Fe S3000AOM (Argentina)

    2016-04-30

    Synthesis and preparation of ZnO films are relevant subjects for obtaining transparent and conducting layers with interesting applications in optoelectronics and photovoltaics. Optimization of parameters such as dopant type and concentration, deposition time and substrate temperature is important for obtaining ZnO layers with optimal properties. In this work we present a study about the induced effects of deposition time on optical and electrical properties of ZnO thin films. These films were deposited by spray pyrolysis of a suitable Zn precursor, obtained through the sol–gel method. The deposition time has direct incidence on internal stress in the crystal structure, generating defects that may affect transparency and electrical transport into the layers. We performed mosaicity measurements, through X-ray diffraction, and used it as a tool to get an insight on structural characteristics and homogeneity of ZnO layers. Also, through this technique, we analyzed thickness and doping effects on crystallinity and carrier transport properties. - Highlights: • Al-doped ZnO films with high conductivity and moderate Hall mobility were obtained. • Mosaicity between crystalline domains increased with film thickness. • Lattice parameters a and c diminished linearly as a function of Al concentration. • First steps for developing porous silicon/doped ZnO heterojunctions were presented.

  4. Highly doped ZnO films deposited by spray-pyrolysis. Design parameters for optoelectronic applications

    International Nuclear Information System (INIS)

    Garcés, F.A.; Budini, N.; Schmidt, J.A.; Arce, R.D.

    2016-01-01

    Synthesis and preparation of ZnO films are relevant subjects for obtaining transparent and conducting layers with interesting applications in optoelectronics and photovoltaics. Optimization of parameters such as dopant type and concentration, deposition time and substrate temperature is important for obtaining ZnO layers with optimal properties. In this work we present a study about the induced effects of deposition time on optical and electrical properties of ZnO thin films. These films were deposited by spray pyrolysis of a suitable Zn precursor, obtained through the sol–gel method. The deposition time has direct incidence on internal stress in the crystal structure, generating defects that may affect transparency and electrical transport into the layers. We performed mosaicity measurements, through X-ray diffraction, and used it as a tool to get an insight on structural characteristics and homogeneity of ZnO layers. Also, through this technique, we analyzed thickness and doping effects on crystallinity and carrier transport properties. - Highlights: • Al-doped ZnO films with high conductivity and moderate Hall mobility were obtained. • Mosaicity between crystalline domains increased with film thickness. • Lattice parameters a and c diminished linearly as a function of Al concentration. • First steps for developing porous silicon/doped ZnO heterojunctions were presented.

  5. Release and transformation of chlorine and potassium during pyrolysis of KCl doped biomass

    DEFF Research Database (Denmark)

    Wang, Yang; Wu, Hao; Sárossy, Zsuzsa

    2017-01-01

    –850 °C), and KCl contents (0–5 wt%). The volatiles were collected and analyzed for CH3Cl concentration by GC–MS. The solid residue was analyzed by ICP-OES for the contents of total and water soluble K and Cl. Considerable amounts of CH3Cl, corresponding to 20–50% of the fuel chlorine, were formed......The formation of CH3Cl and the transformation of chlorine and potassium during pyrolysis of biomass were investigated. Model biomass compounds (cellulose, xylan, lignin and pectin) and pine wood doped with KCl were pyrolysed in a TGA at different heating rates (10–1000 °C/min), temperatures (300...

  6. Zirconium doped TiO{sub 2} thin films deposited by chemical spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Juma, A. [Laboratory of Thin Film Chemical Technologies, Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Department of Physics and Astronomy, Botswana International University of Science and Technology, Private bag 16, Palapye (Botswana); Oja Acik, I., E-mail: ilona.oja@ttu.ee [Laboratory of Thin Film Chemical Technologies, Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Oluwabi, A.T.; Mere, A. [Laboratory of Thin Film Chemical Technologies, Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Mikli, V.; Danilson, M. [Chair of Semiconductor Materials Technology, Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Krunks, M. [Laboratory of Thin Film Chemical Technologies, Department of Materials Science, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia)

    2016-11-30

    Highlights: • Mean crystallite size of TiO{sub 2}:Zr film decreases with increasing [Zr] in the solution. • Zr doping supresses the anatase to rutile transformation process in TiO{sub 2} films. • Band gap of TiO{sub 2}:Zr film is 3.4 eV irrespective of the annealing temperature. - Abstract: 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 TiO{sub 2} 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 TiO{sub 2} thin films were uniform and homogeneous showing much smaller grains than the undoped TiO{sub 2} 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 TiO{sub 2} film from 5.9 to 1.1 nm. An XRD study of samples with the highest Zr amount showed the ZrTiO{sub 4} phase started forming after annealing at 800 °C. The optical band gap for TiO{sub 2} decreased from 3.3 eV to 3.0 eV after annealing at 800 °C but for the TiO{sub 2}: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.

  7. Doped nanocrystalline ZnO powders for non-linear resistor applications by spray pyrolysis method.

    Science.gov (United States)

    Hembram, Kaliyan; Vijay, R; Rao, Y S; Rao, T N

    2009-07-01

    Homogeneous and doped nanocrystalline ZnO powders (30-200 nm) were synthesized by spray pyrolysis technique. The spray pyrolysed powders were calcined in the temperature range of 500-750 degrees C. Formation of insulating pyrochlore phase started from 700 degrees C during the calcination itself. The calcined powders were compacted and sintered at different temperatures ranging from 900-1200 degrees C for 0.5-4 h. The densification behavior was found to be dependent on calcination temperature of the nanopowder. The resulting discs were found to have density (5.34-5.62 g/cc) in the range of 96-99% of theoretical density. The breakdown voltage value obtained for the nanopowder based non-linear resistor is 10.3 kV/cm with low leakage current density of 0.7 microA/cm2 and coefficient of nonlinearity as high as 193. The activation energy for grain growth of the doped ZnO nanopowder powders is 449.4 +/- 15 kJ/mol.

  8. [Influence of impurities on waste plastics pyrolysis: products and emissions].

    Science.gov (United States)

    Zhao, Lei; Wang, Zhong-Hui; Chen, De-Zhen; Ma, Xiao-Bo; Luan, Jian

    2012-01-01

    The study is aimed to evaluate the impact of impurities like food waste, paper, textile and especially soil on the pyrolysis of waste plastics. For this purpose, emissions, gas and liquid products from pyrolysis of waste plastics and impurities were studied, as well as the transfer of element N, Cl, S from the substrates to the pyrolysis products. It was found that the presence of food waste would reduce the heat value of pyrolysis oil to 27 MJ/kg and increase the moisture in the liquid products, therefore the food residue should be removed from waste plastics; and the soil, enhance the waste plastics' pyrolysis by improving the quality of gas and oil products. The presence of food residue, textile and paper leaded to higher gas emissions.

  9. Effect of tin doping on the optical properties of indium oxide films by a spray pyrolysis method

    International Nuclear Information System (INIS)

    Ibrahim Abu Talib; Muhammad Mat Salleh; Muhammad Yahya; Mod Noor Bader Sher

    1993-01-01

    Thin films of stannum doped indium oxide were deposited on glass by a X-ray pyrolysis method. The substrate temperature and the rate of flow of the carrier gas were fixed at 450 0 C and 2.5 litre/minute respectively during deposition. The dependence of the optical properties of the films on the doping concentration was studied. It is found that the transmission of the visible wavelengths (300 to 800 nm) through the films increases around 5% from 74.9% as the film was doped with 10% stannum. It is also found that the optical energy bandgap increases 0.2 eV from 3.16 to 3.36 eV by doping the film with 10% stannum. The increase is attributed to the Bernstein-Moss (1) and self-energy (2) effects

  10. Morphological differences in transparent conductive indium-doped zinc oxide thin films deposited by ultrasonic spray pyrolysis

    International Nuclear Information System (INIS)

    Jongthammanurak, Samerkhae; Cheawkul, Tinnaphob; Witana, Maetapa

    2014-01-01

    In-doped ZnO thin films were deposited on glass substrates by an ultrasonic spray pyrolysis technique, using indium chloride (InCl 3 ) as a dopant and zinc acetate solution as a precursor. Increasing the [at.% In]/[at.% Zn] ratio changed the crystal orientations of thin films, from the (100) preferred orientation in the undoped, to the (101) and (001) preferred orientations in the In-doped ZnO thin films with 4 at.% and 6–8 at.%, respectively. Undoped ZnO thin film shows relatively smooth surface whereas In-doped ZnO thin films with 4 at.% and 6–8 at.% show surface features of pyramidal forms and hexagonal columns, respectively. X-ray diffraction patterns of the In-doped ZnO thin films with [at.% In]/[at.% Zn] ratios of 6–8% presented an additional peak located at 2-theta of 32.95°, which possibly suggested that a metastable Zn 7 In 2 O 10 phase was present with the ZnO phase. ZnO thin films doped with 2 at.% In resulted in a sheet resistance of ∼ 645 Ω/sq, the lowest value among thin films with [at.% In]/[at.% Zn] ratio in a range of 0–8%. The precursor molarity was changed between 0.05 M and 0.20 M at an [at.% In]/[at.% Zn] ratio of 2%. Increasing the precursor molarity in a range of 0.10 M–0.20 M resulted in In-doped ZnO thin films with the (100) preferred orientation. An In-doped ZnO thin film deposited by 0.20 M precursor showed a sheet resistance of 25 Ω/sq, and an optical transmission of 75% at 550 nm wavelength. The optical band gap estimated from the transmission result was 3.292 eV. - Highlights: • Indium-doped ZnO thin films were grown on glass using ultrasonic spray pyrolysis. • Thin films' orientations depend on In doping and Zn molarity of precursor solution. • Highly c-axis or a-axis orientations were found in the In-doped ZnO thin films. • In doping of 6–8 at.% may have resulted in ZnO and a metastable Zn 7 In 2 O 10 phases. • Increasing precursor molarity reduced sheet resistance of In-doped ZnO thin films

  11. Efficient acetone sensor based on Ni-doped ZnO nanostructures prepared by spray pyrolysis technique

    Science.gov (United States)

    Darunkar, Swapnil S.; Acharya, Smita A.

    2018-05-01

    Ni-doped ZnO thin film was prepared by home-built spray pyrolysis unit for the detection of acetone at 300°C. Scanning electron microscopic (SEM) images of as-developed thin film of undoped ZnO exhibits large quantity of spherical, non-agglomerated particles with uniform size while in Ni-doped ZnO, particles are quite non-uniform in nature. The particle size estimated by using image J are obtained to be around 20-200 nm. Ni-doping effect on band gaps are determined by UV-vis optical spectroscopy and band gap of Ni-doped ZnO is found to be 3.046 eV. Nickel doping exceptionally enhances the sensing response of ZnO as compared to undoped ZnO system. The major role of the Ni-doping is to create more active sites for chemisorbed oxygen on the surface of sensor and correspondingly, to improve the sensing response. The 6 at.% of Ni-doped ZnO exhibits the highest response (92%) for 100 ppm acetone at 300 °C.

  12. Characterization of luminescent samarium doped HfO2 coatings synthesized by spray pyrolysis technique

    International Nuclear Information System (INIS)

    Chacon-Roa, C; Guzman-Mendoza, J; Aguilar-Frutis, M; Garcia-Hipolito, M; Alvarez-Fragoso, O; Falcony, C

    2008-01-01

    Trivalent samarium (Sm 3+ ) doped hafnium oxide (HfO 2 ) films were deposited using the spray pyrolysis deposition technique. The films were deposited on Corning glass substrates at temperatures ranging from 300 to 550 deg. C using chlorides as raw materials. Films, mostly amorphous, were obtained when deposition temperatures were below 350 deg. C. However, for temperatures higher than 400 deg. C, the films became polycrystalline, presenting the HfO 2 monoclinic phase. Scanning electron microscopy of the films revealed a rough surface morphology with spherical particles. Also, electron energy dispersive analysis was performed on these films. The photoluminescence and cathodoluminescence characteristics of the HfO 2 : SmCl 3 films, measured at room temperature, exhibited four main bands centred at 570, 610, 652 and 716 nm, which are due to the well-known intra-4f transitions of the Sm 3+ ion. It was found that the overall emission intensity rose as the deposition temperature was increased. Furthermore, a concentration quenching of the luminescence intensity was also observed

  13. Morphology-controllable of Sn doped ZnO nanorods prepared by spray pyrolysis for transparent electrode application

    Science.gov (United States)

    Hameed, M. Shahul; Princice, J. Joseph; Babu, N. Ramesh; Zahirullah, S. Syed; Deshmukh, Sampat G.; Arunachalam, A.

    2018-05-01

    Transparent conductive Sn doped ZnO nanorods have been deposited at various doping level by spray pyrolysis technique on glass substrate. The structural, surface morphological and optical properties of these films have been investigated with the help of X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscope (AFM) and UV-Vis spectrophotometer respectively. XRD patterns revealed a successful high quality growth of single crystal ZnO nanorods with hexagonal wurtzite structure having (002) preferred orientation. The scanning electron microscope (SEM) image of the prepared films exposed the uniform distribution of Sn doped ZnO nanorod shaped grains. All these films were highly transparent in the visible region with average transmittance of 90%.

  14. Fabrication and properties of samarium doped calcium sulphate thin films using spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Reghima, Meriem [Université Tunis El Manar, Faculté des Sciences de Tunis, Département de Physique, LR99ES13 Laboratoire de Physique de la Matière Condensée (LPMC), 2092 Tunis, Tunisie (Tunisia); Institut d' Electronique et des systèmes, Unité Mixte de Recherche 5214 UM2-CNRS (ST2i) – Université Montpellier, 860 rue de Saint Priest, Bâtiment 5, 34097 Montpellier (France); Faculté des Sciences de Bizerte, Université de Carthage, Zarzouna 7021 (Tunisia); Guasch, Cathy [Institut d' Electronique et des systèmes, Unité Mixte de Recherche 5214 UM2-CNRS (ST2i) – Université Montpellier, 860 rue de Saint Priest, Bâtiment 5, 34097 Montpellier (France); Azzaza, Sonia; Alleg, Safia [Laboratoire de Magnétisme et Spectroscopie des Solides (LM2S), Département de Physique, Faculté des Sciences, Université Badji Mokhtar Annaba, B.P. 12, 23000 Annaba (Algeria); Kamoun-Turki, Najoua [Université Tunis El Manar, Faculté des Sciences de Tunis, Département de Physique, LR99ES13 Laboratoire de Physique de la Matière Condensée (LPMC), 2092 Tunis, Tunisie (Tunisia)

    2016-10-01

    Using low cost spray pyrolysis technique, polycrystalline CaSO{sub 4} thin films were successfully grown on a glass substrate with a thickness of about 1 μm. Samarium doping has been performed on CaSO{sub 4} thin films to explore luminescence properties. The characterizations of these films were carried out using X-ray diffraction, Scanning Electron Microscopy and optical measurements. The structural analyses reveal the existence of hexagonal CaSO{sub 4} phase with a (200) preferred orientation belonging to CaS compound for substrate temperatures below 350 °C. It is shown that the crystallinity of the sprayed thin films can be improved by increasing substrate temperature up to 250 °C. Warren-Averbach analysis has been applied on X-ray diffractogram to determine structural parameters involving the phase with its amount, the grain size and the lattice parameters using Maud software. The surface topography shows a rough surface covered by densely packed agglomerated clusters having faceted and hexagonal shapes. Energy dispersive microscopy measurements confirm the presence of calcium and sulfur in equal proportions as well as high percentage of oxygen. Photoluminescence at room temperature revealed that luminescence peaks are attributed to the intrinsic emission of pure CaSO{sub 4} phase. - Highlights: • Warren Averbach analysis reveal the presence of hcp structure of CaSO{sub 4} phase. • A mixture of CaSO{sub 4} and CaHO{sub 4.5}S phases has been detected for lower T{sub s}. • For increasing T{sub s}, the CaHO{sub 4.5}S phase has been disappeared. • The origin of PL peaks has been identified.

  15. Defect-induced magnetism in undoped and Mn-doped wide band gapzinc oxide grown by aerosol spray pyrolysis

    CSIR Research Space (South Africa)

    Motaung, DE

    2014-08-01

    Full Text Available Surface Science Vol. 311, pp 14-26 Defect-induced magnetism in undoped and Mn-doped wide band gapzinc oxide grown by aerosol spray pyrolysis D.E. Motaunga,∗, I. Kortidise, D. Papadakie, S.S. Nkosib,∗∗, G.H. Mhlongoa,J. Wesley-Smitha, G.F. Malgasc, B....W. Mwakikungaa, E. Coetseed, H.C. Swartd,G. Kiriakidise,f, S.S. Raya aDST/CSIR Nanotechnology Innovation Centre, National Centre for Nano-Structured Materials, Council for Scientific and Industrial Research, P.O. Box 395,Pretoria 0001, South Africa b...

  16. Influence of Pyrolysis Temperature and Production Conditions on Switchgrass Biochar for Use as a Soil Amendment

    Directory of Open Access Journals (Sweden)

    Amanda Joy Ashworth

    2014-10-01

    Full Text Available Biochars form recalcitrant carbon and increase water and nutrient retention in soils; however, the magnitude is contingent upon production conditions and thermo-chemical conversion processes. Herein we aim at (i characterizing switchgrass (Panicum virgatum L.-biochar morphology, (ii estimating water-holding capacity under increasing ratios of char: soil; and, (iii determining nutrient profile variation as a function of pyrolysis conversion methodologies (i.e. continuous, auger pyrolysis system versus batch pyrolysis systems for terminal use as a soil amendment. Auger system chars produced at 600°C had the greatest lignin portion by weight among the biochars produced from the continuous system. On the other hand, a batch pyrolysis system (400 °C – 3h yielded biochar with 73.10% lignin (12 fold increases, indicating higher recalcitrance, whereas lower production temperatures (400 °C yielded greater hemicellulose (i.e. greater mineralization promoting substrate. Under both pyrolysis methods, increasing biochar soil application rates resulted in linear decreases in bulk density (g cm-3. Increases in auger-char (400 °C applications increased soil water-holding capacities; however, application rates of >2 Mt ha-1 are required. Pyrolysis batch chars did not influence water-holding abilities (P>0.05. Biochar macro and micronutrients increased, as the pyrolysis temperature increased in the auger system from 400 to 600 °C, and the residence time increased in the batch pyrolysis system from 1 to 3 h. Conversely, nitrogen levels tended to decrease under the two previously mentioned conditions. Consequently, not all chars are inherently equal, in that varying operation systems, residence times, and production conditions greatly affect uses as a soil amendment and overall rate of efficacy.

  17. Pyrolysis temperature influences ameliorating effects of biochars on acidic soil.

    Science.gov (United States)

    Wan, Qing; Yuan, Jin-Hua; Xu, Ren-Kou; Li, Xing-Hui

    2014-02-01

    The biochars were prepared from straws of canola, corn, soybean, and peanut at different temperatures of 300, 500, and 700 °C by means of oxygen-limited pyrolysis.Amelioration effects of these biochars on an acidic Ultisol were investigated with incubation experiments, and application rate of biochars was 10 g/kg. The incorporation of these biochars induced the increase in soil pH, soil exchangeable base cations, base saturation, and cation exchange capacity and the decrease in soil exchangeable acidity and exchangeable Al. The ameliorating effects of biochars on acidic soil increased with increase in their pyrolysis temperature. The contribution of oxygen-containing functional groups on the biochars to their ameliorating effects on the acidic soil decreased with the rise in pyrolysis temperature, while the contribution from carbonates in the biochars changed oppositely. The incorporation of the biochars led to the decrease in soil reactive Al extracted by 0.5mol/L CuCl2, and the content of reactive Al was decreased with the increase in pyrolysis temperature of incorporated biochars. The biochars generated at 300 °C increased soil organically complexed Al due to ample quantity of oxygen-containing functional groups such as carboxylic and phenolic groups on the biochars, while the biochars generated at 500 and 700 °C accelerated the transformation of soil exchangeable Al to hydroxyl-Al polymers due to hydrolysis of Al at higher pH. Therefore, the crop straw-derived biochars can be used as amendments for acidic soils and the biochars generated at relatively high temperature have great ameliorating effects on the soils.

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

    Energy Technology Data Exchange (ETDEWEB)

    Denayer, Jessica [Group of Research in Energy and Environment for MATerials (GREENMAT), University of Liège, allée de la chimie 3, 4000 Liège (Belgium); Bister, Geoffroy [Environmental and Material Research Association (CRIBC-INISMa), avenue gouverneur cornez 4, 7000 Mons (Belgium); Simonis, Priscilla [Laboratory LPS, University of Namur, rue de bruxelles 61, 5000 Namur (Belgium); Colson, Pierre; Maho, Anthony [Group of Research in Energy and Environment for MATerials (GREENMAT), University of Liège, allée de la chimie 3, 4000 Liège (Belgium); Aubry, Philippe [Environmental and Material Research Association (CRIBC-INISMa), avenue gouverneur cornez 4, 7000 Mons (Belgium); Vertruyen, Bénédicte [Group of Research in Energy and Environment for MATerials (GREENMAT), University of Liège, allée de la chimie 3, 4000 Liège (Belgium); Henrist, Catherine, E-mail: catherine.henrist@ulg.ac.be [Group of Research in Energy and Environment for MATerials (GREENMAT), University of Liège, allée de la chimie 3, 4000 Liège (Belgium); Lardot, Véronique; Cambier, Francis [Environmental and Material Research Association (CRIBC-INISMa), avenue gouverneur cornez 4, 7000 Mons (Belgium); Cloots, Rudi [Group of Research in Energy and Environment for MATerials (GREENMAT), University of Liège, allée de la chimie 3, 4000 Liège (Belgium)

    2014-12-01

    Highlights: • Surfactant-assisted USP: a novel and low cost process to obtain high quality nickel oxide films, with or without lithium dopant. • Increased uniformity and reduced light scattering thanks to the addition of a surfactant. • Improved electrochromic performance (coloration efficiency and contrast) for lithium-doped films by comparison with the undoped NiO film. - Abstract: 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. The effect of strontium doping on structural and morphological properties of ZnO nanofilms synthesized by ultrasonic spray pyrolysis method

    Directory of Open Access Journals (Sweden)

    A. Ouhaibi

    2018-03-01

    Full Text Available Pristine and strontium doped ZnO nanometric films were successfully synthesized on heated glass substrates by the ultrasonic spray pyrolysis technique. The samples were characterized by means of X-ray diffraction (XRD, Atomic Force Microscope (AFM, UV–visible spectroscopy and photoluminescence (PL. X-ray diffraction patterns confirmed the hexagonal (wurtzite structure, where the most pronounced (002 peak indicates the preferential orientation along the c-axis perpendicular to the sample surface. The intensity of this peak was increased rapidly from the first doping of 1% and its position was shifted toward higher angles under Sr-doping effect. For the used doping range of 1–5%, the Sr-doping at 3% attracted an especial attention. At this concentration, the particular transformation in the surface morphology of doped ZnO films was observed. The surface became granular and rough by expanding the crystallites' size. From optical measurements, transmittance and PL spectra were found to be sensitive to Sr-doping, where two different behaviors were observed before and after 3% of Sr-doping. Keywords: Ultrasonic spray pyrolysis, Sr-doped ZnO, Morphology study, Optical properties

  20. Structural and magnetic properties of Co-doped ZnO thin films grown by ultrasonic spray pyrolysis method

    Science.gov (United States)

    Baghdad, R.; Lemée, N.; Lamura, G.; Zeinert, A.; Hadj-Zoubir, N.; Bousmaha, M.; Bezzerrouk, M. A.; Bouyanfif, H.; Allouche, B.; Zellama, K.

    2017-04-01

    Cobalt-doped ZnO thin films with several different percentage of Co from 0 up to 15 at% were synthesized via a cheap, simple and versatile method i.e. ultrasonic spray pyrolysis at atmospheric pressure and a substrate temperature of 350 °C. The structure of the as-prepared samples was characterized by X-ray diffraction (XRD), Raman spectroscopy and FTIR. The Co-doping effect is revealed by the presence of three additional peaks around 235, 470 and 538 cm-1 respect to the Raman spectra of the unsubstituted film. Fourier transform infrared spectroscopy (FTIR) put in evidence the decrease of the bond force constant f with increasing Co-doping. By ultra-violet visible near infrared (UV-Vis-NIR) spectroscopy on Co-doped samples it was possible to show the presence of additional absorption bands at approximately 570, 620 and 660 nm suggesting that Co2+ ions do not change their oxidation when substituted to zinc and the ZnO lattice does not change its wurtzite structure as well. Finally, all our samples exhibit a paramagnetic behavior without any trace of intrinsic room temperature ferromagnetism.

  1. Transparent nanostructured Fe-doped TiO2 thin films prepared by ultrasonic assisted spray pyrolysis technique

    Science.gov (United States)

    Rasoulnezhad, Hossein; Hosseinzadeh, Ghader; Ghasemian, Naser; Hosseinzadeh, Reza; Homayoun Keihan, Amir

    2018-05-01

    Nanostructured TiO2 and Fe-doped TiO2 thin films with high transparency were deposited on glass substrate through ultrasonic-assisted spray pyrolysis technique and were used in the visible light photocatalytic degradation of MB dye. The resulting thin films were characterized by scanning electron microscopy (SEM), Raman spectroscopy, photoluminescence spectroscopy, x-ray diffraction (XRD), and UV-visible absorption spectroscopy techniques. Based on Raman spectroscopy results, both of the TiO2 and Fe-doped TiO2 films have anatase crystal structure, however, because of the insertion of Fe in the structure of TiO2 some point defects and oxygen vacancies are formed in the Fe-doped TiO2 thin film. Presence of Fe in the structure of TiO2 decreases the band gap energy of TiO2 and also reduces the electron–hole recombination rate. Decreasing of the electron–hole recombination rate and band gap energy result in the enhancement of the visible light photocatalytic activity of the Fe-doped TiO2 thin film.

  2. Double-layer indium doped zinc oxide for silicon thin-film solar cell prepared by ultrasonic spray pyrolysis

    International Nuclear Information System (INIS)

    Jiao Bao-Chen; Zhang Xiao-Dan; Wei Chang-Chun; Sun Jian; Ni Jian; Zhao Ying

    2011-01-01

    Indium doped zinc oxide (ZnO:In) thin films were prepared by ultrasonic spray pyrolysis on corning eagle 2000 glass substrate. 1 and 2 at.% indium doped single-layer ZnO:In thin films with different amounts of acetic acid added in the initial solution were fabricated. The 1 at.% indium doped single-layers have triangle grains. The 2 at.% indium doped single-layer with 0.18 acetic acid adding has the resistivity of 6.82×10 −3 Ω·cm and particle grains. The double-layers structure is designed to fabricate the ZnO:In thin film with low resistivity (2.58×10 −3 Ω·cm) and good surface morphology. It is found that the surface morphology of the double-layer ZnO:In film strongly depends on the substrate-layer, and the second-layer plays a large part in the resistivity of the double-layer ZnO:In thin film. Both total and direct transmittances of the double-layer ZnO:In film are above 80% in the visible light region. Single junction a-Si:H solar cell based on the double-layer ZnO:In as front electrode is also investigated. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  3. Zr-doped SnO2 thin films synthesized by spray pyrolysis technique for barrier layers in solar cells

    Science.gov (United States)

    Reddy, N. Nanda Kumar; Akkera, Harish Sharma; Sekhar, M. Chandra; Park, Si-Hyun

    2017-12-01

    In the present work, we investigated the effect of Zr doping (0-6 at%) on the structural, electrical, and optical properties of tin oxide (SnO2) thin films deposited onto glass substrates using a spray pyrolysis technique. The room-temperature X-ray diffraction pattern shows that all deposited films exhibit polycrystalline tetragonal structure. The pure SnO2 film is grown along a preferred (200) direction, whereas Zr-doped SnO2 (Zr:SnO2) films started growing along the (220) orientation along with a high intensity peak of (200). Scanning electron microscope (SEM) and atomic force microscope (AFM) images showed that the grains of the films are spherical in structure, and the grain size decreased with increasing of Zr concentration. The optical transmission spectra of deposited films as a function of wavelength confirm that the average optical transmittance is > 85% for Zr:SnO2 films. The value of the optical bandgap is significantly decreased from 3.94 to 3.68 eV with increasing Zr concentration. Furthermore, the electrical measurements found that the sheet resistance ( R sh) and resistivity ( ρ) values are decreased with increasing of Zr doping. The lowest values of R sh = 6.82 Ω and ρ = 0.4 × 10- 3 Ω cm are found in 6-at% Zr-doped SnO2 film. In addition, a good efficiency value of the figure of merit ( ɸ = 3.35 × 10- 3 Ω-1) is observed in 6-at% Zr-doped SnO2 film. These outstanding properties of Zr-doped SnO2 films make them useful for several optoelectronic device applications.

  4. Influence of reaction conditions on fast pyrolysis of macroalge

    International Nuclear Information System (INIS)

    Bae, Yoon Ju; Kim, Jung Hwan; Cho, Hye Jung; Ko, Jeong Huy; Heo, Hyeon Su; Park, Hye Jin; Park, Young Kwon

    2010-01-01

    Full text: The importance of renewable energy sources has increased rapidly due to the high international crude oil prices and environmental concerns over fossil fuel use. Recently, there has been a growing interest in aquatic biomass, especially marine macro algae, and a number of studies have been initiated to evaluate its potential for bio-energy. This paper reports a fast pyrolysis of macro algae under different reaction conditions such as pyrolysis temperature, particle size and sample quantity. Various macro algae such as Undaria pinnatifida, Laminaria japonica and Porphyra tenera were fast pyro lysed at temperatures between 300-600 degree Celsius in a batch reactor and the main product of bio-oil was obtained. The optimal reaction temperature for the production of bio-oil was 500 degree Celsius. At this temperature, the maximum bio-oil yields were 40.4 wt % ( by Undaria pinnatifida), 37.6 wt % (by Laminaria japonica) and 47.4 wt % (by Porphyra tenera), respectively. In particular, after pre-treatment with 2.0M HCl solution, the product yield of bio-oil was increased in macro algae, Undaria pinnatifida. The pyroylsis gases were analyzed by using GC-TCD and GC-FID and qualitative analyses of bio-oil were performed using GC-MS. The maximum yield of bio-oil, Undaria pinnatifida, Laminaria japonica and Porphyra tenera, was obtained at 500 degree Celsius (40.4 wt %, 37.6 wt % and 47.4 wt %, respectively). (author)

  5. TG-FTIR Study of the Influence of potassium Chloride on Wheat Straw Pyrolysis

    DEFF Research Database (Denmark)

    Jensen, Anker; Dam-Johansen, Kim; Wójtowicz, M.A.

    1998-01-01

    of products into char, tar and gas. In this work, a combination of thermogravimetry and evolved gas analysis by Fourier transform infrared analysis (TG-FTIR) has been applied to study the influence of potassium chloride (KCl) on wheat straw pyrolysis. Raw straw, washed straw and washed straw impregnated...

  6. Influence of fast pyrolysis conditions on yield and structural transformation of biomass chars

    DEFF Research Database (Denmark)

    Trubetskaya, Anna; Jensen, Peter Arendt; Jensen, Anker Degn

    2015-01-01

    Fast pyrolysis of biomass (wood, straw, rice husk) and its major components (cellulose, hemicellulose, lignin) was conducted in a wire mesh reactor. The aim of this study was to understand the influence of temperature (350-1400 ° C), heating rate (10-3000 ° C/s), particle size (0.05-2 mm) and hol...

  7. Influence of the Pyrolysis Temperature on Sewage Sludge Product Distribution, Bio-Oil, and Char Properties

    DEFF Research Database (Denmark)

    Trinh, Ngoc Trung; Jensen, Peter Arendt; Dam-Johansen, Kim

    2013-01-01

    Fast pyrolysis may be used for sewage sludge treatment with the advantages of a significant reduction of solid waste volume and production of a bio-oil that can be used as fuel. A study of the influence of the reaction temperature on sewage sludge pyrolysis has been carried out using a pyrolysis...... of 392 g/mol, and metal concentrations lower than 0.14 wt % on a dry basis (db). Less optimal oil properties with respect to industrial applications were observed for oil samples obtained at 475 and 625 °C. Char properties of the 575 °C sample were an ash content of 81 wt % and a HHV of 6.1 MJ/kg db...

  8. Influence of pressure on pyrolysis of black liquor: 1. Swelling.

    Science.gov (United States)

    Whitty, Kevin; Backman, Rainer; Hupa, Mikko

    2008-02-01

    This is the first of two papers concerning the behavior of black liquor during pyrolysis under pressurized conditions. Two industrial kraft liquors were pyrolyzed in a laboratory-scale pressurized single particle reactor and a pressurized grid heater at temperatures ranging from 650 to 1100 degrees C and at pressures between 1 and 20 bar. The dimensions of the chars produced were measured and the specific swollen volume was calculated. Swelling decreased roughly logarithmically over the pressure range 1-20 r. An expression is developed to predict the specific swollen volume at elevated pressure when the volume at 1 bar is known. The bulk density of the char increased with pressure, indicating that liquors will be entrained less easily at higher pressures.

  9. Structural, electrical and optical properties of indium chloride doped ZnO films synthesized by Ultrasonic Spray Pyrolysis technique

    International Nuclear Information System (INIS)

    Zaleta-Alejandre, E.; Camargo-Martinez, J.; Ramirez-Garibo, A.; Pérez-Arrieta, M.L.; Balderas-Xicohténcatl, R.; Rivera-Alvarez, Z.; Aguilar-Frutis, M.; Falcony, C.

    2012-01-01

    Indium chloride doped zinc oxide (ZnO:In) thin films were deposited onto glass substrates using zinc acetate by Ultrasonic Spray Pyrolysis technique. The effect of substrate temperature, deposition time and acetic acid added to the spraying solution on the structural, electrical and optical properties of these ZnO:In films is reported. The films were in all cases polycrystalline with a hexagonal (wurtzite) structure, a transparency over 80% and resistivity of the order of 10 −3 –10 −2 Ω·cm. The resistivity was dependent on the volume % of acetic acid added to the spraying solution. The minimum resistivity value was obtained with a 5 vol.% acetic acid (pH = 3.71) at substrate temperature of 450 °C. The deposition rates obtained were as high as 180 Å·min −1 at a substrate temperature of 450 °C. - Highlights: ► Conductive ZnO:In thin films were deposited by Ultrasonic Spray Pyrolysis (USP). ► USP is of low cost, high growth rates and scalable for industrial applications. ► USP is appropriate for the deposition of metallic oxide films. ► We studied the effect of acetic acid, time deposition and substrate temperature. ► Zinc acetate and indium chloride were used as precursor materials.

  10. Structural, electrical and optical properties of indium chloride doped ZnO films synthesized by Ultrasonic Spray Pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Zaleta-Alejandre, E., E-mail: ezaleta@fis.cinvestav.mx [Centro de Investigacion y de Estudios Avanzados-IPN, Departamento de Fisica, Apdo, Postal 14-470, Del. Gustavo A. Madero, C.P. 07000, Mexico, D.F. (Mexico); Camargo-Martinez, J.; Ramirez-Garibo, A. [Centro de Investigacion y de Estudios Avanzados-IPN, Departamento de Fisica, Apdo, Postal 14-470, Del. Gustavo A. Madero, C.P. 07000, Mexico, D.F. (Mexico); Perez-Arrieta, M.L. [Universidad Autonoma de Zacatecas, Unidad Academica de Fisica, Calzada Solidaridad esq. Paseo, La Bufa s/n, C.P. 98060, Zacatecas, Mexico (Mexico); Balderas-Xicohtencatl, R.; Rivera-Alvarez, Z. [Centro de Investigacion y de Estudios Avanzados-IPN, Departamento de Fisica, Apdo, Postal 14-470, Del. Gustavo A. Madero, C.P. 07000, Mexico, D.F. (Mexico); Aguilar-Frutis, M. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada-IPN, Legaria 694, Col. Irrigacion, Del. Miguel Hidalgo, Mexico, D.F. (Mexico); Falcony, C. [Centro de Investigacion y de Estudios Avanzados-IPN, Departamento de Fisica, Apdo, Postal 14-470, Del. Gustavo A. Madero, C.P. 07000, Mexico, D.F. (Mexico)

    2012-12-01

    Indium chloride doped zinc oxide (ZnO:In) thin films were deposited onto glass substrates using zinc acetate by Ultrasonic Spray Pyrolysis technique. The effect of substrate temperature, deposition time and acetic acid added to the spraying solution on the structural, electrical and optical properties of these ZnO:In films is reported. The films were in all cases polycrystalline with a hexagonal (wurtzite) structure, a transparency over 80% and resistivity of the order of 10{sup -3}-10{sup -2} Ohm-Sign {center_dot}cm. The resistivity was dependent on the volume % of acetic acid added to the spraying solution. The minimum resistivity value was obtained with a 5 vol.% acetic acid (pH = 3.71) at substrate temperature of 450 Degree-Sign C. The deposition rates obtained were as high as 180 A{center_dot}min{sup -1} at a substrate temperature of 450 Degree-Sign C. - Highlights: Black-Right-Pointing-Pointer Conductive ZnO:In thin films were deposited by Ultrasonic Spray Pyrolysis (USP). Black-Right-Pointing-Pointer USP is of low cost, high growth rates and scalable for industrial applications. Black-Right-Pointing-Pointer USP is appropriate for the deposition of metallic oxide films. Black-Right-Pointing-Pointer We studied the effect of acetic acid, time deposition and substrate temperature. Black-Right-Pointing-Pointer Zinc acetate and indium chloride were used as precursor materials.

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

    Science.gov (United States)

    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%.

  12. Structural, Optical and Electrical Properties of Transparent Conducting Oxide Based on Al Doped ZnO Prepared by Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    Abdeslam DOUAYAR

    2014-05-01

    Full Text Available Aluminum doped zinc oxide (AZO thin films were deposited on glass substrates at 350 °C by spray pyrolysis technique. X-ray diffraction patterns show that the undoped and AZO films exhibit the hexagonal wűrtzite crystal structure with a preferential orientation along 2 direction. AFM images showed that AZO film with 3 % of Al has a uniform grain sizes with a surface roughness of about 24 nm. All films present a high transmittance in the visible range. Both undoped and AZO films were n-type degenerate semiconductor and the best electrical resistivity value was around 8.0 ´ 10- 2 W.cm obtained for 3 % Al content.

  13. Characterization and Gas Sensing Properties of Copper-doped Tin Oxide Thin Films Deposited by Ultrasonic Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    Zhaoxia ZHAI

    2016-05-01

    Full Text Available Tin oxide-based thin films are deposited by ultrasonic spray pyrolysis technology, in which Cu addition is introduced to enhance the gas sensing performance by H2S detection. The thin films are porous and comprise nano-sized crystallites. One of the Cu-containing thin film sensors demonstrates a fast and significant response to H2S gas. The values of power law exponent n are calculated to discuss the sensitivity of the sensors, which is significantly promoted by Cu additive. The sensitivity of Cu-doped SnO2 gas sensors is determined by two mechanisms. One is the normal gas sensing mechanism of SnO2 grains, and the other is the promoted mechanism caused by the transformation between CuO and CuS in the H2S detection. DOI: http://dx.doi.org/10.5755/j01.ms.22.2.12917

  14. Deposition of tin oxide doped with fluorine produced by sol-gel method and deposited by spray-pyrolysis

    International Nuclear Information System (INIS)

    Maia, Paulo Herbert Franca; Lima, Francisco Marcone; Sena, Aline Cosmo de; Silva, Alvaro Neuton; Almeida, Ana Fabiola Leite de; Freire, Francisco Nivaldo Aguiar

    2014-01-01

    Solar energy is one of the most important sources of renewable energy today, but its production is based on silicon cells, expensive and difficult to produce, so the research seek new materials to replace them. This work aims to deposit tin oxide doped with fluorine on the glass substrate using the sol-gel method to provide a working solution and spray pyrolysis technique to perform the deposition. F-SnO2 (FTO) were synthesized by sol-gel method, employing NH_4F and SnCl_2 precursor in an ethanol solution. Before the formation of the gel phase, the entire solution was sprayed, with the aid of a pistol aerographic substrate under heated at 600 °C divided by 50 applications and cooled in the furnace. The substrates had resistances between 10 and 30 S.cm. The energy dispersive x-ray (EDS) revealed the presence of fluorine in the SnO_2 network. (author)

  15. Nanocrystalline Pt-doped TiO2 thin films prepared by spray pyrolysis ...

    Indian Academy of Sciences (India)

    Administrator

    Spray pyrolysis techniques; TiO2 thin films; hydrogen gas response. 1. Introduction ... tion is necessary during the production, storage and use of hydrogen. It is also ..... ient, and 'green': it may be used to large scale industrial application for ...

  16. Catalytic pyrolysis of woody biomass in a fluidized bed reactor: influence of the zeolite structure

    Energy Technology Data Exchange (ETDEWEB)

    A. Aho; N. Kumar; K. Eranen; T. Salmi; M. Hupa; D.Yu. Murzin [Aabo Akademi University, Aabo/Turku (Finland). Process Chemistry Centre, Laboratory of Industrial Chemistry and Reaction Engineering

    2008-09-15

    Catalytic pyrolysis of biomass from pine wood was carried out in a fluidized bed reactor at 450{sup o}C. Different structures of acidic zeolite catalysts were used as bed material in the reactor. Proton forms of Beta, Y, ZSM-5, and Mordenite were tested as catalysts in the pyrolysis of pine, while quartz sand was used as a reference material in the non-catalytic pyrolysis experiments. The yield of the pyrolysis product phases was only slightly influenced by the structures, at the same time the chemical composition of the bio-oil was dependent on the structure of acidic zeolite catalysts. Ketones and phenols were the dominating groups of compounds in the bio-oil. The formation of ketones was higher over ZSM-5 and the amount of acids and alcohols lower than over the other bed materials tested. Mordenite and quartz sand produced smaller quantities of polyaromatic hydrocarbons than the other materials tested. It was possible to successfully regenerate the spent zeolites without changing the structure of the zeolite. 12 refs., 9 figs., 5 tabs.

  17. Influence of fast pyrolysis temperature on biochar labile fraction and short-term carbon loss in a loamy soil

    DEFF Research Database (Denmark)

    Bruun, Esben; Hauggaard-Nielsen, Henrik; Ibrahim, Norazana

    2011-01-01

    Production of bio-oil, gas and biochar from pyrolysis of biomass is considered a promising technology for combined production of bioenergy and recalcitrant carbon (C) suitable for sequestration in soil. Using a fast pyrolysis centrifuge reactor (PCR) the present study investigated the relation...... between fast pyrolysis of wheat straw at different reactor temperatures and the short-term degradability of biochar in soil. After 115 days incubation 3–12% of the added biochar-C had been emitted as CO2. On average, 90% of the total biochar-C loss occurred within the first 20 days of the experiment......, emphasizing the importance of knowing the biochar labile fraction when evaluating a specific biochars C sequestration potential. The pyrolysis temperature influenced the outputs of biochar, bio-oil and syngas significantly, as well as the stability of the biochar produced. Contrary to slow pyrolysis a fast...

  18. High power density cell using nanostructured Sr-doped SmCoO3 and Sm-doped CeO2 composite powder synthesized by spray pyrolysis

    Science.gov (United States)

    Shimada, Hiroyuki; Yamaguchi, Toshiaki; Suzuki, Toshio; Sumi, Hirofumi; Hamamoto, Koichi; Fujishiro, Yoshinobu

    2016-01-01

    High power density solid oxide electrochemical cells were developed using nanostructure-controlled composite powder consisting of Sr-doped SmCoO3 (SSC) and Sm-doped CeO2 (SDC) for electrode material. The SSC-SDC nano-composite powder, which was synthesized by spray pyrolysis, had a narrow particle size distribution (D10, D50, and D90 of 0.59, 0.71, and 0.94 μm, respectively), and individual particles were spherical, composing of nano-size SSC and SDC fragments (approximately 10-15 nm). The application of the powder to a cathode for an anode-supported solid oxide fuel cell (SOFC) realized extremely fine cathode microstructure and excellent cell performance. The anode-supported SOFC with the SSC-SDC cathode achieved maximum power density of 3.65, 2.44, 1.43, and 0.76 W cm-2 at 800, 750, 700, and 650 °C, respectively, using humidified H2 as fuel and air as oxidant. This result could be explained by the extended electrochemically active region in the cathode induced by controlling the structure of the starting powder at the nano-order level.

  19. Influence of torrefaction on the characteristics and pyrolysis behavior of cellulose

    International Nuclear Information System (INIS)

    Wang, Shurong; Dai, Gongxin; Ru, Bin; Zhao, Yuan; Wang, Xiaoliu; Xiao, Gang; Luo, Zhongyang

    2017-01-01

    The influence of torrefaction on cellulose structural characteristics and the resulting pyrolysis behavior was investigated in this study. Torrefaction reduced O/C ratio in cellulose and increased its high heating value. The crystallinity of cellulose increased slightly first and then decreased sharply with the increase of torrefaction temperature, which could be ascribed to competitive degradation between crystalline region and amorphous region, as indicated by "1"3C CP/MAS NMR analysis. Besides, the cleavage of β-1,4-glycosidic bond and the dehydration of hydroxyl were the major reactions occurring in torrefaction. Avrami-Erofeev model was found to be the most suitable kinetic reaction model for explaining the thermogravimetric weight loss during the pyrolysis of the raw and torrefied cellulose. A distributed activation energy model based on Avrami-Erofeev model was subsequently used to reveal the pyrolytic kinetics. It was found that the changes in cellulose structure influenced the kinetic parameters greatly. Torrefaction also changed pyrolytic product distribution. The yields of furfural, alicyclic ketones and anhydrosugars increased while that of 5-hydroxymethyl-furfural decreased as torrefaction temperature increased. - Highlights: • Competitive degradation of crystalline and amorphous regions caused CrI change. • Cleavage of glycosidic bond and dehydration of hydroxyl occurred during torrefaction. • Am-DAEM was used to analyze the raw and torrefied cellulose pyrolysis kinetics. • Torrefaction changed cellulose pyrolytic products distribution greatly.

  20. Nature and electronic properties of Y-junctions in CNTs and N-doped CNTs obtained by the pyrolysis of organometallic precursors

    Science.gov (United States)

    Deepak, F. L.; John, Neena Susan; Govindaraj, A.; Kulkarni, G. U.; Rao, C. N. R.

    2005-08-01

    Carbon nanotubes (CNTs) and N-doped CNTs with Y-junctions have been prepared by the pyrolysis of nickelocene-thiophene and nickel phthalocyanine-thiophene mixtures, respectively, the latter being reported for the first time. The junctions are free from the presence of sulfur and contain only carbon or carbon and nitrogen. The electronic properties of the junction nanotubes have been investigated by scanning tunneling microscopy. Tunneling conductance measurements reveal rectifying behavior with regions of coulomb blockade, the effect being much larger in the N-doped junction nanotubes.

  1. Effect of copper concentration on the physical properties of copper doped NiO thin films deposited by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Mani Menaka, S., E-mail: manimenaka.phy@gmail.com [PG and Research Department of Physics, Government Arts College, Coimbatore, 641018, Tamilnadu (India); Umadevi, G. [PG and Research Department of Physics, Government Arts College, Coimbatore, 641018, Tamilnadu (India); Manickam, M. [SRMV College of Arts and Science, Coimbatore, 641020, Tamilnadu (India)

    2017-04-15

    The spray pyrolysis (SP) technique is an important and powerful method for the preparation of nickel oxide (NiO) and copper-doped nickel oxide thin films. The best films were obtained when the substrate temperature, T{sub s} = 450 °C on glass substrates. Copper (Cu) concentrations in the films were varied from 0 to 8%. The effect of Cu concentration on the structural, morphological, spectral, optical, and electrical properties of the thin films were studied by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transformed infrared spectroscopy (FTIR), UV–vis–NIR spectrophotometer, Hot probe and Hall system. The X-ray diffraction result shows the polycrystalline cubic structure of sprayed films with (200) preferred orientation. The variations of the structural parameters such as lattice parameters and grain sizes were investigated. The SEM image displays the surface morphology of the NiO and Cu:NiO thin films. The FTIR of the as-deposited films were associated with chemical identification. The optical transmittance and absorbance spectra of the films were measured by UV–vis–NIR spectrophotometer. The absorption coefficient and band gaps of the films were calculated using the optical method. All the NiO and Cu:NiO films were p-type. The resistivity of the above films decreases with the increase in copper concentration and so the conductivity of the films depend on the precursor concentration. - Highlights: • Pure and Cu:NiO films were deposited by Spray pyrolysis technique. • The XRD result shows the polycrystalline nature of pure and Cu:NiO films. • The formation of pure and Cu:NiO were confirmed by FTIR analysis. • Band gap values of pure and Cu:NiO decreases. • All the pure and Cu:NiO films were p-type.

  2. Effect of copper concentration on the physical properties of copper doped NiO thin films deposited by spray pyrolysis

    International Nuclear Information System (INIS)

    Mani Menaka, S.; Umadevi, G.; Manickam, M.

    2017-01-01

    The spray pyrolysis (SP) technique is an important and powerful method for the preparation of nickel oxide (NiO) and copper-doped nickel oxide thin films. The best films were obtained when the substrate temperature, T_s = 450 °C on glass substrates. Copper (Cu) concentrations in the films were varied from 0 to 8%. The effect of Cu concentration on the structural, morphological, spectral, optical, and electrical properties of the thin films were studied by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transformed infrared spectroscopy (FTIR), UV–vis–NIR spectrophotometer, Hot probe and Hall system. The X-ray diffraction result shows the polycrystalline cubic structure of sprayed films with (200) preferred orientation. The variations of the structural parameters such as lattice parameters and grain sizes were investigated. The SEM image displays the surface morphology of the NiO and Cu:NiO thin films. The FTIR of the as-deposited films were associated with chemical identification. The optical transmittance and absorbance spectra of the films were measured by UV–vis–NIR spectrophotometer. The absorption coefficient and band gaps of the films were calculated using the optical method. All the NiO and Cu:NiO films were p-type. The resistivity of the above films decreases with the increase in copper concentration and so the conductivity of the films depend on the precursor concentration. - Highlights: • Pure and Cu:NiO films were deposited by Spray pyrolysis technique. • The XRD result shows the polycrystalline nature of pure and Cu:NiO films. • The formation of pure and Cu:NiO were confirmed by FTIR analysis. • Band gap values of pure and Cu:NiO decreases. • All the pure and Cu:NiO films were p-type.

  3. Influence of pyrolysis conditions on the structure and gasification reactivity of biomass chars

    Energy Technology Data Exchange (ETDEWEB)

    E. Cetin; B. Moghtaderi; R. Gupta; T.F. Wall [University of Newcastle, Callaghan, NSW (Australia). Discipline of Chemical Engineering, Faculty of Engineering and Built Environment, School of Engineering

    2004-11-01

    The physical and chemical structure as well as gasification reactivities of chars generated from several biomass species (i.e. pinus radiata, eucalyptus maculata and sugar cane bagasse) were studied to gain insight into the role of heating rate and pressure on the gasification characteristics of biomass chars. Char samples were generated in a suite of reactors including a wire mesh reactor, a tubular reactor, and a drop tube furnace. Scanning electron microscopy analysis, X-ray diffractometry, digital cinematography and surface area analysis were employed to determine the impact of operating conditions on the char structure. The global gasification reactivities of char samples were also determined for a range of pressures between 1 and 20 bar using pressurised thermogravimetric analysis technique. Char reactivities were found to increase with increasing pyrolysis heating rates and decreasing pyrolysis pressure. It was found that under high heating rates the char particles underwent plastic deformation (i.e. melted) developing a structure different to that of the virgin biomass. Pressure was also found to influence the physical and chemical structures of char particles. The difference in the gasification reactivities of biomass chars at pressure was found to correlate well with the effect of pyrolysis pressure on the graphitisation process in the biomass char structure. 29 refs., 18 figs., 2 tabs.

  4. Transparent conducting properties of Ni doped zinc oxide thin films prepared by a facile spray pyrolysis technique using perfume atomizer

    Energy Technology Data Exchange (ETDEWEB)

    Bouaoud, A.; Rmili, A.; Ouachtari, F.; Louardi, A.; Chtouki, T. [Laboratoire des Hautes Energies, Sciences de l' Ingenierie et Reacteurs (LHESIR), Equipe Ingenierie et Materiaux (INMA), Departement de Physique, Faculte des Sciences, Kenitra (Morocco); Elidrissi, B., E-mail: e.bachir@mailcity.com [Laboratoire des Hautes Energies, Sciences de l' Ingenierie et Reacteurs (LHESIR), Equipe Ingenierie et Materiaux (INMA), Departement de Physique, Faculte des Sciences, Kenitra (Morocco); Erguig, H. [Laboratoire des Hautes Energies, Sciences de l' Ingenierie et Reacteurs (LHESIR), Equipe Ingenierie et Materiaux (INMA), Departement de Physique, Faculte des Sciences, Kenitra (Morocco); Ecole Nationale des Sciences Appliquees de Kenitra (ENSAK) (Morocco)

    2013-01-15

    Undoped and Ni doped zinc oxide (Ni-ZnO) thin films were prepared by a facile spray pyrolysis technique using perfume atomizer from aqueous solution of anhydrous zinc acetate (Zn(CH{sub 3}COOH){sub 2} and hexahydrated nickel chloride (NiCl{sub 2}{center_dot}6H{sub 2}O) as sources of zinc and nickel, respectively. The films were deposited onto the amorphous glass substrates kept at (450 Degree-Sign C). The effect of the [Ni]/[Zn] ratio on the structural, morphological, optical and electrical properties of Ni doped ZnO thin film was studied. It was found from X-ray diffraction (XRD) analysis that both the undoped and Ni doped ZnO films were crystallized in the hexagonal structure with a preferred orientation of the crystallites along the [002] direction perpendicular to the substrate. The scanning electron microscopy (SEM) images showed a relatively dense surface structure composed of crystallites in the spherical form whose average size decreases when the [Ni]/[Zn] ratio increases. The optical study showed that all the films were highly transparent. The optical transmittance in the visible region varied between 75 and 85%, depending on the dopant concentrations. The variation of the band gap versus the [Ni]/[Zn] ratio showed that the energy gap decreases from 2.95 to 2.72 eV as the [Ni]/[Zn] ratio increases from 0 to 0.02 and then increases to reach 3.22 eV for [Ni]/[Zn] = 0.04. The films obtained with the [Ni]/[Zn] ratio = 0.02 showed minimum resistivity of 2 Multiplication-Sign 10{sup -3} {Omega} cm at room temperature. -- Highlights: Black-Right-Pointing-Pointer The optical transmittance of Ni doped ZnO varies between 75 and 85%. Black-Right-Pointing-Pointer The energy gap of these films decreases from 2.95 to 2.72 eV as the [Ni]/[Zn] ratio increases from 0 to 0.02. Black-Right-Pointing-Pointer The energy gap increases to reach 3.22 eV for [Ni]/[Zn] = 0.04. Black-Right-Pointing-Pointer The films obtained with [Ni]/[Zn] ratio = 0.02 show minimum resistivity of 2

  5. FAST PYROLYSIS PROCESS OF ORANGE SOLID WASTE. FACTORS INFLUENCE IN THE PROCESS

    Directory of Open Access Journals (Sweden)

    Leonardo Aguiar Trujillo

    2015-04-01

    Full Text Available The orange processing industry generates high volumes of solid residue. This residue has been used in animal feeding and biochemical processes. A possible energy use of the waste can be thermochemical fast pyrolysis process. The objective was to determine the influence of the heating rate and temperature in the process of rapid pyrolysis of orange solid residue. In the process a design, 2k full factorial experiment was used, evaluating the influence of the independent variables and its interactions on the answers, using a 95 % significance level. We found that temperature is the most significant influence on the responses parameter having significant influence on the yields to: gas, coal, tar and the calorific value of the gas and the heating rate does not influence the answers. Finally, the interaction affects the gas yield. The results obtained in this study are: Rgas (19 – 38 %, Rchar (25 – 42 %, Ralq (6 – 12 %, PCIgas entre (140 – 1050 kJ/m3N.

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

    Energy Technology Data Exchange (ETDEWEB)

    Novruzov, V.D. [Department of Physics, Recep Tayyip Erdogan University, Rize (Turkey); Keskenler, E.F., E-mail: keskenler@gmail.com [Department of Nanotechnology Engineering, Recep Tayyip Erdogan University, Rize (Turkey); Tomakin, M. [Department of Physics, Recep Tayyip Erdogan University, Rize (Turkey); Kahraman, S. [Department of Physics, Mustafa Kemal University, Hatay (Turkey); Gorur, O. [Department of Physics, Abant Izzet Baysal University, Bolu (Turkey)

    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/Cu{sub 2}S solar cell were investigated and it was determined that photoelectrical parameters of B-doped solar cell were more durable against the UV light.

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

    Science.gov (United States)

    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.

  8. Compositional dependence of optical and electrical properties of indium doped zinc oxide (IZO) thin films deposited by chemical spray pyrolysis

    Science.gov (United States)

    Dintle, Lawrence K.; Luhanga, Pearson V. C.; Moditswe, Charles; Muiva, Cosmas M.

    2018-05-01

    The structural and optoelectronic properties of undoped and indium doped zinc oxide (IZO) thin films grown on glass substrates through a simple reproducible custom-made pneumatic chemical spray pyrolysis technique are presented. X-ray diffraction (XRD) results showed a polycrystalline structure of hexagonal wurtzite phase growing preferentially along the (002) plane for the undoped sample. Increase in dopant content modified the orientation leading to more pronounced (100) and (101) reflections. Optical transmission spectra showed high transmittance of 80-90% in the visible range for all thin films. The optical band gap energy (Eg) was evaluated on the basis of the derivative of transmittance (dT/dλ) versus wavelength (λ) model and Tauc's extrapolation method in the region where the absorption coefficient, α ≥ 104 cm-1. The observed values of Eg were found to decrease generally with increasing In dopant concentration. From the figure of merit calculations a sample with 4 at.% In dopant concentration showed better optoelectronic properties.

  9. Influence of fast pyrolysis temperature on biochar labile fraction and short-term carbon loss in a loamy soil

    International Nuclear Information System (INIS)

    Bruun, Esben W.; Hauggaard-Nielsen, Henrik; Ibrahim, Norazana; Egsgaard, Helge; Ambus, Per; Jensen, Peter A.; Dam-Johansen, Kim

    2011-01-01

    Production of bio-oil, gas and biochar from pyrolysis of biomass is considered a promising technology for combined production of bioenergy and recalcitrant carbon (C) suitable for sequestration in soil. Using a fast pyrolysis centrifuge reactor (PCR) the present study investigated the relation between fast pyrolysis of wheat straw at different reactor temperatures and the short-term degradability of biochar in soil. After 115 days incubation 3-12% of the added biochar-C had been emitted as CO 2 . On average, 90% of the total biochar-C loss occurred within the first 20 days of the experiment, emphasizing the importance of knowing the biochar labile fraction when evaluating a specific biochars C sequestration potential. The pyrolysis temperature influenced the outputs of biochar, bio-oil and syngas significantly, as well as the stability of the biochar produced. Contrary to slow pyrolysis a fast pyrolysis process may result in incomplete conversion of biomass due to limitations to heat transfer and kinetics. In our case chemical analysis of the biochars revealed unconverted cellulosic and hemicellulosic fractions, which in turn were found to be proportional with the short-term biochar degradation in soil. As these labile carbohydrates are rapidly mineralized, their presence lowers the biochar-C sequestration potential. By raising the pyrolysis temperature, biochar with none or low contents of these fractions can be produced, but this will be on the expense of the biochar quantity. The yield of CO 2 neutral bio-oil is the other factor to optimize when adjusting the pyrolysis temperature settings to give the overall greatest climate change mitigation effect.

  10. Characterization of luminescent praseodymium-doped ZrO{sub 2} coatings deposited by ultrasonic spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Ramos-Brito, F [Laboratorio de Materiales Optoelectronicos, DiDe, Centro de Ciencias de Sinaloa, Av. De las Americas No. 2771 Nte. Col. Villa Universidad, C.P. 80010 Culiacan, Sinaloa (Mexico); Garcia-Hipolito, M [Departamento de Materiales Metalicos y Ceramicos, Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, AP 70-360 Coyoacan 04510 DF (Mexico); Alejo-Armenta, C [Laboratorio de Materiales Optoelectronicos, DiDe, Centro de Ciencias de Sinaloa, Av. De las Americas No. 2771 Nte. Col. Villa Universidad, C.P. 80010 Culiacan, Sinaloa (Mexico); Alvarez-Fragoso, O [Departamento de Materiales Metalicos y Ceramicos, Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, AP 70-360 Coyoacan 04510 DF (Mexico); Falcony, C [Departamento de Fisica, CINVESTAV-IPN, Apdo. Postal 14-740, 07000 DF (Mexico)

    2007-11-07

    ZrO{sub 2} : Pr films were synthesized by the ultrasonic spray pyrolysis process. X-ray diffraction studies, as a function of the deposition temperature, indicate a tetragonal crystal structure of zirconia as the substrate temperature was increased. Luminescence (photo- and cathodoluminescence) properties of the films were studied as a function of growth parameters such as the substrate temperature and the praseodymium concentration. For an excitation wavelength of 290 nm, all the photoluminescent emission spectra show peaks located at 490, 510, 566, 615, 642, 695, 718, 740 and 833 nm, associated with the electronic transitions {sup 3} P{sub 0} {yields} {sup 3}H{sub 4}, {sup 3}P{sub 0} {yields} {sup 3} H{sub 4}, {sup 3}P{sub 1} + {sup 1}I{sub 6} {yields} {sup 3}H{sub 5}, {sup 1}D{sub 2} {yields} {sup 3}H{sub 4}, {sup 3} P{sub 0} {yields} {sup 3}H{sub 6}, {sup 1}D{sub 2} {yields} {sup 3} H{sub 5}, {sup 1}D{sub 2} {yields} {sup 3}H{sub 5}, {sup 3} P{sub 0} {yields} {sup 3}F{sub 3,4} and {sup 1}D{sub 2} {yields} {sup 3} F{sub 2} of the Pr{sup 3+} ion. As the deposition temperature is increased, an increasing intensity of the luminescence emission is observed. Also, quenching of the luminescence, with increasing doping concentration, is observed. The chemical composition of the films as determined by energy dispersive spectroscopy is reported as well. In addition, the surface morphology characteristics of the films, as a function of the deposition temperature, are presented.

  11. Influence of Carbonization Temperature on Physicochemical Properties of Biochar derived from Slow Pyrolysis of Durian Wood (Durio zibethinus Sawdust

    Directory of Open Access Journals (Sweden)

    Zaira Zaman Chowdhury

    2016-02-01

    Full Text Available The objective of this study was to explore the influence of pyrolysis temperature on the physicochemical properties of biochar synthesized from durian wood (Durio zibethinus sawdust. Surface morphological features, including the porosity and BET surface area of biochars, provide appropriate dimensions for growing clusters of microorganisms with excellent water retention capacity in soil. Oxygen-containing surface functional groups play a vital role in improving soil fertility by increasing its cation and anion exchange capacities with reduced leaching of nutrients from the soil surface. Biochar was produced via slow pyrolysis of woody biomass (WS using a fixed bed reactor under an oxygen-free atmosphere at different pyrolysis temperatures (350, 450, and 550 °C. The biochars obtained were characterized using ultimate and proximate analyses, Brunauer-Emmett-Teller (BET surface area, field-emission scanning electron microscopy (FE-SEM, Fourier transform infrared spectroscopy (FTIR, and X-ray diffraction (XRD. The yield of biochar decreased from 66.46 to 24.56%, whereas the BET surface area increased sharply from 2.567 to 220.989 m2/g, when the pyrolysis temperature was increased from 350 to 550 °C. The results highlighted the effect of pyrolysis temperature on the structure of the biochar, which could be advantageous for agricultural industries.

  12. Influence of nature of the substrate in the deposition of yttria-stabilized zirconia by spray pyrolysis

    International Nuclear Information System (INIS)

    Halmenschlager, C.M.; Malfatti, C.F.; Bergmann, C.P.; Neagu, R.

    2012-01-01

    Spray pyrolysis technique consist in spraying a precursor solution on a heated substrate. In the last few decades this process has attracted much attention because of its versatility. Controlling the parameters is possible to produce dense or porous film. Spray pyrolysis has been applied to obtain several materials such as electrodes or electrolytes for SOFC, semiconductors, materials for solar cells and so on. However, some behaviors such as Leidenfrost effect have been poorly considered and it may affect the coating quality. This work aims to evaluate the influence of the substrate and how Leidenfrost effect affects the coating by spray pyrolysis. To achieve this goal yttria-stabilized zirconia solutions made with different solvents were deposited on different substrates at different temperatures. These coatings were characterized by X-ray diffraction and scanning electron microscopy. The results show that there is a limit temperature which is related to properties of the solvent and the surface of the substrates where films are continuous. (author)

  13. Influence of solvent on the morphology and microstructure of YSZ films obtained by spray pyrolysis technique

    International Nuclear Information System (INIS)

    Falcade, T.; Oliveira, G.B.; Mueller, I.L.; Malfatti, C.F.

    2010-01-01

    This work aims to investigate the influence of solvent used for the deposition of thin films of yttria stabilized zirconia (YSZ) on porous substrate. The films were obtained directly on the porous LSM substrate by spray pyrolysis technique, which consists of spraying a precursor solution containing salts of zirconium (Zr (C 6 H 7 O 2 ) 4) and yttrium (YCl 3 .6H 2 O), dissolved in specific solvents, on the heated substrate. The use of solvents with different boiling points and viscosity aims the optimization of experimental operating parameters to obtain homogeneous and dense films suitable for application as electrolyte in fuel cells, solid oxide (SOFC). The films were characterized by scanning electron microscopy, infrared spectroscopy and X-ray diffraction. (author)

  14. Modelling of biomass pyrolysis

    International Nuclear Information System (INIS)

    Kazakova, Nadezhda; Petkov, Venko; Mihailov, Emil

    2015-01-01

    Pyrolysis is an essential preliminary step in a gasifier. The first step in modelling the pyrolysis process of biomass is creating a model for the chemical processes taking place. This model should describe the used fuel, the reactions taking place and the products created in the process. The numerous different polymers present in the organic fraction of the fuel are generally divided in three main groups. So, the multistep kinetic model of biomass pyrolysis is based on conventional multistep devolatilization models of the three main biomass components - cellulose, hemicelluloses, and lignin. Numerical simulations have been conducted in order to estimate the influence of the heating rate and the temperature of pyrolysis on the content of the virgin biomass, active biomass, liquid, solid and gaseous phases at any moment. Keywords: kinetic models, pyrolysis, biomass pyrolysis.

  15. High selectivity and stability of Mg-doped Al-MCM-41 for in-situ catalytic upgrading fast pyrolysis bio-oil

    International Nuclear Information System (INIS)

    Karnjanakom, Surachai; Suriya-umporn, Thanyamai; Bayu, Asep; Kongparakul, Suwadee; Samart, Chanatip; Fushimi, Chihiro; Abudula, Abuliti; Guan, Guoqing

    2017-01-01

    Highlights: • Mg-doped Al-MCM-41 was developed for in-situ catalytic upgrading of bio-oils. • Mg/Al-MCM-41 exhibited high selectivity to aromatic hydrocarbons. • The ratio of produced hydrocarbon reached up to 80% in upgraded bio-oil. • 1 wt.% Mg/Al-MCM-41 showed the highest catalytic activity. • Mg/Al-MCM-41 had stable reusability due to its coking inhabitation ability. - Abstract: In-situ catalytic upgrading of bio-oils derived from the fast pyrolysis of cellulose, lignin or sunflower stalk over Mg-doped Al-MCM-41 was investigated in details. It is found that Mg species with doping amounts ranged between 0.25 and 10 wt.% was well dispersed on Al-MCM-41, and that doping Mg on Al-MCM-41 effectively adjusted the acidity and basicity of the catalysts, resulting in significant improvement of bio-oil quality. Mg/Al-MCM-41 exhibited high selective conversion of bio-oils derived from cellulose, lignin or sunflower stalk to high value-added aromatic hydrocarbons via catalytic cracking, deoxygenation and aromatization. In the upgraded bio-oil, the relative total hydrocarbon amount reached up to approximately ≥80%, which consisted of aromatic hydrocarbon approximately 76% and aliphatic hydrocarbon approximately 4% for all feedstocks. The selectivity to the monocyclic aromatic hydrocarbons (MAHs) such as benzene, toluene and xylenes (BTXs) increased while the coke formed on the catalyst decreased with the increase in Mg doping amount. 1 wt.% Mg/Al-MCM-41 resulted in the highest relative total hydrocarbon amount in the upgraded bio-oil at lower catalytic deoxygenation temperature, and showed stable reusability for at least 5 cycles. It is expected that Mg/Al-MCM-41 can be widely applied for bio-oil upgrading in a practical process.

  16. Influence of the spray pyrolysis seeding and growth parameters on the structure and optical properties of ZnO nanorod arrays

    Energy Technology Data Exchange (ETDEWEB)

    Rodríguez, Juan, E-mail: jrodriguez@uni.edu.pe [Facultad de Ciencias, Universidad Nacional de Ingeniería, P.O. Box 31-139, Lima 31 (Peru); Feuillet, Guy [CEA Grenoble/LETI, 17 rue des Martyrs, F-38054 Grenoble Cedex 9 (France); Donatini, Fabrice [Univ. Grenoble Alpes, Inst NEEL, F-38000 Grenoble (France); CNRS, Inst NEEL, F-38042 Grenoble (France); Onna, Diego [DQIAQF-INQUIMAE, FCEyN-Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, 1428 Buenos Aires (Argentina); Sanchez, Luis [Facultad de Ciencias, Universidad Nacional de Ingeniería, P.O. Box 31-139, Lima 31 (Peru); Candal, Roberto [DQIAQF-INQUIMAE, FCEyN-Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, 1428 Buenos Aires (Argentina); ECyT, 3iA, Universidad Nacional de San Martín, Martín de Irigoyen N° 3100 (1650), San Martín, Pcia de Buenos Aires (Argentina); Marchi, M. Claudia [DQIAQF-INQUIMAE, FCEyN-Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, 1428 Buenos Aires (Argentina); CMA, FCEyN-Universidad de Buenos Aires, Ciudad Universitaria, Pab. I, 1428 Buenos Aires (Argentina); Bilmes, Sara A. [DQIAQF-INQUIMAE, FCEyN-Universidad de Buenos Aires, Ciudad Universitaria, Pab. II, 1428 Buenos Aires (Argentina); Chandezon, Frédéric [University Grenoble Alpes, INAC-SPRAM, F-38000 Grenoble (France); CNRS, INAC-SPRAM, F-38000 Grenoble (France); CEA, INAC-SPRAM, F-38000 Grenoble (France)

    2015-02-01

    ZnO nanorods (NRs) were grown on fluorine doped tin oxide (FTO) substrates at low temperatures (90 °C) from Zn{sup 2+} precursors in alkaline media previously seeded with ZnO nanoparticles. These were deposited onto the FTO substrate heated at 350 °C by spray pyrolysis of a Zn acetate solution in a water ethanol mixture. The structure of seeds was tuned by the ethanol to water ratio, Γ, which controls the solvent evaporation rate of drops impinging the substrate. From a detailed characterization using a combination of scanning electron microscopy, X-ray diffraction, UV–visible absorption and cathodoluminescence spectroscopies, the dependence of the morphology and optical properties of the ZnO NRs on the seeding conditions was demonstrated. NRs grown on seeds deposited from solutions with Γ in the 0.03–0.06 range – i.e. when the surface excess of ethanol in the water–ethanol mixture has a maximum – show thinner average diameters and stacking faults due to the presence of zinc blende domains embedded into an overall wurtzite NR. They furthermore exhibit blue-shifted near band edge emission peak and a high deep level emission in cathodoluminescence. All these findings support the use of spray pyrolysis as a simple and reproducible way to control the seeds deposition, influencing the growth, the structure and the optical properties of the final ZnO NRs. - Highlights: • ZnO pyrolytic seeds tuned by the rate of solvent evaporation. • ZnO NRs grown from tuned pyrolytic seed's structure shows diameter dependence. • ZnO NRs show stacking faults due to the presence of zinc blende domains.

  17. The electrical, optical, structural and thermoelectrical characterization of n- and p-type cobalt-doped SnO 2 transparent semiconducting films prepared by spray pyrolysis technique

    Science.gov (United States)

    Bagheri-Mohagheghi, Mohammad-Mehdi; Shokooh-Saremi, Mehrdad

    2010-10-01

    The electrical, optical and structural properties of Cobalt (Co) doped SnO 2 transparent semiconducting thin films, deposited by the spray pyrolysis technique, have been studied. The SnO 2:Co films, with different Co-content, were deposited on glass substrates using an aqueous-ethanol solution consisting of tin and cobalt chlorides. X-ray diffraction studies showed that the SnO 2:Co films were polycrystalline only with tin oxide phases and preferential orientations along (1 1 0) and (2 1 1) planes and grain sizes in the range 19-82 nm. Optical transmittance spectra of the films showed high transparency ∼75-90% in the visible region, decreasing with increase in Co-doping. The optical absorption edge for undoped SnO 2 films was found to be 3.76 eV, while for higher Co-doped films shifted toward higher energies (shorter wavelengths) in the range 3.76-4.04 eV and then slowly decreased again to 4.03 eV. A change in sign of the Hall voltage and Seebeck coefficient was observed for a specific acceptor dopant level ∼11.4 at% in film and interpreted as a conversion from n-type to p-type conductivity. The thermoelectric electro-motive force (e.m.f.) of the films was measured in the temperature range 300-500 K and Seebeck coefficients were found in the range from -62 to +499 μVK -1 for various Co-doped SnO 2 films.

  18. The electrical, optical, structural and thermoelectrical characterization of n- and p-type cobalt-doped SnO2 transparent semiconducting films prepared by spray pyrolysis technique

    International Nuclear Information System (INIS)

    Bagheri-Mohagheghi, Mohammad-Mehdi; Shokooh-Saremi, Mehrdad

    2010-01-01

    The electrical, optical and structural properties of Cobalt (Co) doped SnO 2 transparent semiconducting thin films, deposited by the spray pyrolysis technique, have been studied. The SnO 2 :Co films, with different Co-content, were deposited on glass substrates using an aqueous-ethanol solution consisting of tin and cobalt chlorides. X-ray diffraction studies showed that the SnO 2 :Co films were polycrystalline only with tin oxide phases and preferential orientations along (1 1 0) and (2 1 1) planes and grain sizes in the range 19-82 nm. Optical transmittance spectra of the films showed high transparency ∼75-90% in the visible region, decreasing with increase in Co-doping. The optical absorption edge for undoped SnO 2 films was found to be 3.76 eV, while for higher Co-doped films shifted toward higher energies (shorter wavelengths) in the range 3.76-4.04 eV and then slowly decreased again to 4.03 eV. A change in sign of the Hall voltage and Seebeck coefficient was observed for a specific acceptor dopant level ∼11.4 at% in film and interpreted as a conversion from n-type to p-type conductivity. The thermoelectric electro-motive force (e.m.f.) of the films was measured in the temperature range 300-500 K and Seebeck coefficients were found in the range from -62 to +499 μVK -1 for various Co-doped SnO 2 films.

  19. Erratum to: Influence of boron doping on mechanical and tribological ...

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... Erratum to: Influence of boron doping on mechanical and tribological properties in multilayer CVD-diamond coating systems. SAJAD HUSSAIN DIN M A SHAH N A SHEIKH K A NAJAR K RAMASUBRAMANIAN S BALAJI M S RAMACHANDRA RAO. Volume 39 Issue 7 December 2016 pp 1763-1763 ...

  20. Influence of halo doping profiles on MOS transistor mismatch

    NARCIS (Netherlands)

    Andricciola, P.; Tuinhout, H.

    2009-01-01

    Halo implants are used in modern CMOS technology to reduce the short channel effect. However, the lateral non-uniformity of the channel doping has been proven to degenerate the mismatch performance. With this paper we want to discuss the influence of the halo profile on MOS transistor mismatch. The

  1. A facile method to synthesize nitrogen and fluorine co-doped TiO2 nanoparticles by pyrolysis of (NH4)2TiF6

    International Nuclear Information System (INIS)

    Chen Daimei; Jiang Zhongyi; Geng Jiaqing; Zhu Juhong; Yang Dong

    2009-01-01

    The nitrogen and fluorine co-doped TiO 2 (N-F-TiO 2 ) nanoparticles of anatase crystalline structure were prepared by a facile method of (NH 4 ) 2 TiF 6 pyrolysis, and characterized by thermogravimetry-differential thermal analysis (TG-DTA), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and ultraviolet visible (UV-Vis) spectroscopy etc. With the increase of calcination temperature, (NH 4 ) 2 TiF 6 decomposed into TiOF 2 and NH 4 TiOF 3 at first, and then formed anatase-type TiO 2 with thin sheet morphology. H 3 BO 3 as oxygen source can promote the formation of anatase TiO 2 , but decrease the F content in the N-F-TiO 2 materials due to the formation of volatile BF 3 during the precursor decomposition. The photocatalytic activity of the obtained N-F-TiO 2 samples was evaluated by the methylene blue degradation under visible light, and all the samples exhibited much higher photocatalytic activity than P25. Moreover, the merits and disadvantages of this proposed method to prepare doped TiO 2 are discussed.

  2. Influence of metal additives on pyrolysis behavior of bituminous coal by TG-FTIR analysis

    Energy Technology Data Exchange (ETDEWEB)

    Su, Wenjuan; Fang, Mengxiang; Cen, Jianmeng; Li, Chao; Luo, Zhongyang; Cen, Kefa [Zhejiang Univ., Hangzhou (China). State Key Lab. of Clean Energy Utilization

    2013-07-01

    To study the catalytic effects of alkali, alkaline earth and transition metal additives on coal pyrolysis behavior, bituminous coal loaded NaCl, KCl, CaCl{sub 2}, MgCl{sub 2}, FeCl{sub 3} and NiCl{sub 2} was respectively investigated using Thermogravimetry and Fourier Transform Infrared Spectroscopy (TG-FTIR). Results indicated that the maximum mass loss rate decreased under the metal additives in the primary pyrolysis stage. The total mass loss of pyrolysis was reduced in metals catalyzed pyrolysis except for Na loaded sample. Kinetic analysis was taken for all samples adopting the method of Coats-Redfern. Activation energy of raw coal in the primary pyrolysis stage was 92.15vkJ.mol{sup -1}, which was lowered to 44.59-73.42 kJ.mol{sup -1} under metal additives. The orders of catalytic effect for this bituminous coal were Mg > Fe > Ca > Ni > K > Na according to their activation energies. Several investigated volatiles including CH{sub 4}, CO{sub 2}, CO, toluene, phenol and formic acid were identified from FTIR spectra. The yields of CH{sub 4}, CO{sub 2}, toluene, phenol and formic acid were decreased, but the evolution of CO was increased. The presence of metals in the coal samples have been involved in a repeated bond-forming and bond-breaking process, which greatly hindered the release of tars during pyrolysis as the tar precursors were connected to coal/char matrix and were thermally cracked, becoming a part of char.

  3. Influence of impregnation by inorganic substances on the yield of pyrolysis products

    Energy Technology Data Exchange (ETDEWEB)

    Shevkoplyas, V N; Saranchuk, V I [AN Ukrainskoj SSR, Donetsk (Ukraine). Inst. Fiziko-Organicheskoj Khimii i Uglekhimii

    1998-09-01

    In papers was shown that fossil coals impregnation by aqueous solution of inorganic substances with a subsequent pyrolysis leads to the rise of the rate and depth of its organic mass destruction into liquid and gaseous products. This is, apperently, conditioned by changes in coals structure already on the stage of treatment. But, there are few papers that study an activating effect of inorganic reactants upon natural coals structure and their behaviour at pyrolysis. One of the methods which allows to judge structural transformation in coals at their impregnation by inorganic substances is an X-ray analysis. (orig.)

  4. Modeling the influence of potassium content and heating rate on biomass pyrolysis

    DEFF Research Database (Denmark)

    Trubetskaya, Anna; Surup, Gerrit; Shapiro, Alexander

    2017-01-01

    This study presents a combined kinetic and particle model that describes the effect of potassium and heating rate during the fast pyrolysis of woody and herbaceous biomass. The model calculates the mass loss rate, over a wide range of operating conditions relevant to suspension firing...

  5. An investigation of the influence of heating modes on ignition and pyrolysis of woody wildland fuel

    Science.gov (United States)

    B.L. Yashwanth; B. Shotorban; S. Mahalingam; D.R. Weise

    2015-01-01

    The ignition of woody wildland fuel modeled as a one-dimensional slab subject to various modes of heating was investigated using a general pyrolysis code, Gpyro. The heating mode was varied by applying different convective and/or radiative, time-dependent heat flux boundary conditions on one end of the slab while keeping the other end insulated. Dry wood properties...

  6. Controllable production of liquid and solid biofuels by doping-free, microwave-assisted, pressurised pyrolysis of hemicellulose

    International Nuclear Information System (INIS)

    Li, T.; Remón, J.; Shuttleworth, P.S.; Jiang, Z.; Fan, J.; Clark, J.H.; Budarin, V.L.

    2017-01-01

    Highlights: • Microwave pyrolysis of xylan in the absence of any external microwave absorber. • High energy-efficient and controllable production of biochar and bio-oil from xylan. • Water in liquid phase is needed for fast microwave pyrolysis. • Production of bio-oil and bio-char with HHVs 52% and 19% greater than that of xylan. - Abstract: Batch, pressurised microwave-assisted pyrolysis of hemicellulose in the absence of any external microwave absorber was found to be a promising route for the production of bio-based chemicals and biofuels. The experiments were conducted in a 10 mL batch reactor using a fixed power of 200 W employing different initial masses of xylan (0.1–0.7 g) for a maximum time, temperature and pressure of 10 min, 250 °C and 200 psi, respectively. The gas, bio-oil and solid (char) yields varied by 16–40%, 2–21% and 40–82%, respectively. Char production is preferential using a low amount of xylan (<0.25 g), while bio-oil production is favoured using a high amount of xylan (0.25–0.7 g). The effect of the sample mass is accounted for by the different physical state of the volatiles released during pyrolysis depending on the pressure attained during the experiment. This permits the process to be easily customised for the selective production of liquid (bio-oil) or solid (bio-char). Regarding the bio-oil, it is composed of a mixture of platform chemicals such as aldehydes, alkenes, phenols, polyaromatic hydrocarbons (PAHC), cyclic ketones and furans, with the composition varying depending on the initial mass of xylan. The char had a higher proportion of C together with a lower proportion of O than the original feedstock. Energy efficiencies of 100 and 26% were achieved for char and bio-oil production, respectively; thus leading to an increase in the HHV of the products (with respect to the original feedstock) of 52% for char and 19% for bio-oil.

  7. Influence of pressure on pyrolysis of black liquor: 2. Char yields and component release.

    Science.gov (United States)

    Whitty, Kevin; Kullberg, Mika; Sorvari, Vesa; Backman, Rainer; Hupa, Mikko

    2008-02-01

    This is the second in a series of papers concerning the behavior of black liquor during pyrolysis at elevated pressures. Two industrial black liquors were pyrolyzed under pressurized conditions in two laboratory-scale devices, a pressurized single-particle reactor and a pressurized grid heater. Temperatures ranging between 650 and 1100 degrees C and pressures in the range 1-20 bar were studied. Char yields were calculated and based on analysis of some of the chars the fate of carbon, sodium, potassium and sulfur was determined as a function of pyrolysis pressure. At temperatures below 800 degrees C little variation in char yield was observed at different pressures. At higher temperatures char yield increased with pressure due to slower decomposition of sodium carbonate. For the same reason, sodium release decreased with pressure. Sulfur release, however, increased with pressure primarily because there was less opportunity for its capture in the less-swollen chars.

  8. Temperature influence on the fast pyrolysis of manure samples: char, bio-oil and gases production

    Science.gov (United States)

    Fernandez-Lopez, Maria; Anastasakis, Kostas; De Jong, Wiebren; Valverde, Jose Luis; Sanchez-Silva, Luz

    2017-11-01

    Fast pyrolysis characterization of three dry manure samples was studied using a pyrolyzer. A heating rate of 600°C/s and a holding time of 10 s were selected to reproduce industrial conditions. The effect of the peak pyrolysis temperature (600, 800 and 1000°C) on the pyrolysis product yield and composition was evaluated. Char and bio-oil were gravimetrically quantified. Scanning electron microscopy (SEM) was used to analyse the char structure. H2, CH4, CO and CO2 were measured by means of gas chromatography (GC). A decrease in the char yield and an increase of the gas yield were observed when temperature increased. From 800°C on, it was observed that the char yield of samples Dig R and SW were constant, which indicated that the primary devolatilization reactions stopped. This fact was also corroborated by GC analysis. The bio-oil yield slightly increased with temperature, showing a maximum of 20.7 and 27.8 wt.% for samples Pre and SW, respectively, whereas sample Dig R showed a maximum yield of 16.5 wt.% at 800°C. CO2 and CO were the main released gases whereas H2 and CH4 production increased with temperature. Finally, an increase of char porosity was observed with temperature.

  9. Temperature influence on the fast pyrolysis of manure samples: char, bio-oil and gases production

    Directory of Open Access Journals (Sweden)

    Fernandez-Lopez Maria

    2017-01-01

    Full Text Available Fast pyrolysis characterization of three dry manure samples was studied using a pyrolyzer. A heating rate of 600°C/s and a holding time of 10 s were selected to reproduce industrial conditions. The effect of the peak pyrolysis temperature (600, 800 and 1000°C on the pyrolysis product yield and composition was evaluated. Char and bio-oil were gravimetrically quantified. Scanning electron microscopy (SEM was used to analyse the char structure. H2, CH4, CO and CO2 were measured by means of gas chromatography (GC. A decrease in the char yield and an increase of the gas yield were observed when temperature increased. From 800°C on, it was observed that the char yield of samples Dig R and SW were constant, which indicated that the primary devolatilization reactions stopped. This fact was also corroborated by GC analysis. The bio-oil yield slightly increased with temperature, showing a maximum of 20.7 and 27.8 wt.% for samples Pre and SW, respectively, whereas sample Dig R showed a maximum yield of 16.5 wt.% at 800°C. CO2 and CO were the main released gases whereas H2 and CH4 production increased with temperature. Finally, an increase of char porosity was observed with temperature.

  10. Influence of reaction parameters on brown coal-polyolefinic plastic co-pyrolysis behavior

    Energy Technology Data Exchange (ETDEWEB)

    Sharypov, V.I.; Beregovtsova, N.G.; Kuznetsov, B.N. [Institute of Chemistry and Chemical Technology SB RAS, K.Marx Str. 42, 660049 Krasnoyarsk (Russian Federation); Cebolla, V.L. [Instituto de Carboquimica, CSIC, Miguel Luesma, 4, 50015 Zaragoza (Spain); Collura, S.; Finqueneisel, G.; Zimny, T.; Weber, J.V. [Laboratoire de Chimie et Applications, Universite de Metz, rue V.Demange, 57500 Saint-Avold (France)

    2007-03-15

    Co-processing of polyolefinic polymers with Kansk-Achinsk (Russia) brown coal was investigated by thermogravimetry (TG) and autoclave pyrolysis under argon and hydrogen pressure in catalytic conditions (or not). Gas chromatography-mass spectrometry (GC-MS) and high performance thin layer chromatography (HPTLC) were used to analyze the distillate products. Some synergistic effects indicate chemical interaction between the products of thermal decomposition of coal and plastic. In co-pyrolysis under H{sub 2} a significant increasing of coal conversion degree as a function of polymer amount in feedstock was found. Simultaneously the coal promoted formation of distillate products from polymers. Some alkyl aromatic and O-containing substances were detected in co-pyrolysis fraction boiling in the range 180-350 C, indicating interactions between coal and plastic. Iron containing ore materials, modified by mechanochemical treatment, demonstrated a catalytic activity in hydropyrolysis process. In catalytic conditions, increases of the mixtures conversion degree by 9-13 wt.%, of distillate fraction yields by 1.2-1.6 times and a decrease of olefins and polycyclic components were observed. (author)

  11. Influence of polystyrene addition to cellulose on chemical structure and properties of bio-oil obtained during pyrolysis

    International Nuclear Information System (INIS)

    Rutkowski, Piotr; Kubacki, Andrzej

    2006-01-01

    The cellulose (C), polystyrene (PS) and cellulose/polystyrene (C-PS) mixtures (3:1, 1:1, 1:3 w/w) were subjected to a pyrolysis process to produce bio-oil. The pyrolytic oil yield was in the range of 45.5-94.8 wt% depending on the composition of the sample. Pyrolysis of polystyrene gives the highest oil yield, whereas for cellulose, the yield of liquid products was the lowest. The basic physicochemical properties of oils are strongly influenced by the original material and do not change additively. The polystyrene addition to cellulose clearly improves the quality of the bio-oil, resulting in decreases in acid number, pour point and density. The change of color is not so distinct. The FT-IR analysis of the oils showed that the oxygen functionalities and hydrocarbons contents highly depend on the composition of the cellulose/polystyrene mixture. The fractionation of bio-oils by column chromatography using hexane and benzene was followed by GC-MS analyses. Different classes of organic compounds were identified, i.e., carboxylic acids, phenols, aldehydes, ketones, esters, ethers and unsaturated linear and cyclic hydrocarbons. The proportion of hydrocarbons increases with a decrease of the cellulose/polystyrene ratio. The obtained results indicate that during pyrolysis, not only does decomposition of cellulose and polystyrene occur, but also, reactions between products from C and PS take place. That was proved by the presence of compounds identified only in the bio-oils obtained from C-PS compositions

  12. Pt-doped In{sub 2}O{sub 3} nanoparticles prepared by flame spray pyrolysis for NO{sub 2} sensing

    Energy Technology Data Exchange (ETDEWEB)

    Inyawilert, K. [Chiang Mai University, Department of Physics and Materials Science, Faculty of Science (Thailand); Channei, D. [Naresuan University, Department of Chemistry, Faculty of Science (Thailand); Tamaekong, N. [Maejo University, Program in Materials Science, Faculty of Science (Thailand); Liewhiran, C. [Chiang Mai University, Department of Physics and Materials Science, Faculty of Science (Thailand); Wisitsoraat, A.; Tuantranont, A. [National Electronics and Computer Technology Center (NECTEC), Nanoelectronics and MEMS Laboratory (Thailand); Phanichphant, S., E-mail: sphanichphant@gmail.com [Chiang Mai University, Faculty of Science, Materials Science Research Center (Thailand)

    2016-02-15

    Undoped In{sub 2}O{sub 3} and 0.25–1.00 wt% M (M=Pt, Nb, and Ru)-doped/loaded In{sub 2}O{sub 3} nanoparticles were successfully synthesized in a single-step flame spray pyrolysis technique using indium nitrate, platinum (II) acetylacetonate, niobium ethoxide, and ruthenium (III) acetylacetonate precursors. The undoped In{sub 2}O{sub 3} and M-doped In{sub 2}O{sub 3} nanoparticles were characterized by Brunauer–Emmett–Teller (BET) analysis, X-ray diffraction (XRD), and scanning and transmission electron microscopy (SEM & TEM). The BET average diameter of spherical nanoparticles was found to be in the range of 10.2–15.2 nm under 5/5 (precursor/oxygen) flame conditions. All XRD peaks were confirmed to correspond to the cubic structure of In{sub 2}O{sub 3}. TEM images showed that there is no Pt nanoparticle loaded on In{sub 2}O{sub 3} surface, suggesting that Pt should form solid solution with the In{sub 2}O{sub 3} lattice. Gas sensing studies showed that 0.5 wt% Pt doping in In{sub 2}O{sub 3} nanoparticles gave a significant enhancement of NO{sub 2} sensing performances in terms of sensor response and selectivity. 0.5 wt% Pt/In{sub 2}O{sub 3} exhibited a high NO{sub 2} response of ∼1904 to 5 ppm NO{sub 2} at 250 °C and good NO{sub 2} selectivity against NO, H{sub 2}S, H{sub 2}, and C{sub 2}H{sub 5}OH. In contrast, Nb and Ru loading resulted in deteriorated NO{sub 2} response. Therefore, Pt is demonstrated to be an effective additive to enhance NO{sub 2} sensing performances of In{sub 2}O{sub 3}-based sensors.

  13. The Influence of Several Doped Ions on Gas Sensitivity of Hematite

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The dehydrating activation energies of the hematite with several doped ions used for the alcohol sensor were determinated by thermogravimetric differential thermal analyzer (TG-DTA) and the grain size of the samples were observed with TEM. The hematites with different doping amounts of Sn4 + were investigated by Mossbauer spectrometer. It shows that the different doped ion is of influence for grain growth of the hematite. The decrease of grain size stemmed from the doped ion causes gas sensitivity for alcohol to increase and the dehydrating activation energy to decrease correspondingly. When the different amounts of Sn4 + is doped in hematite, the microstructure of the hematite can be influenced.

  14. Catalytic Pyrolysis of Chilean Oak: Influence of Brønsted Acid Sites of Chilean Natural Zeolite

    Directory of Open Access Journals (Sweden)

    Serguei Alejandro Martín

    2017-11-01

    Full Text Available This paper proposes the Chilean natural zeolite as catalyst on bio-oil upgrade processes. The aim of this study was to analyze chemical composition of bio-oil samples obtained from catalytic pyrolysis of Chilean native oak in order to increase bio-oil stability during storage. In order to identify chemical compounds before and after storage, biomass pyrolysis was carried out in a fixed bed reactor at 623 K and bio-oil samples were characterized by gas chromatography/mass spectrophotometry (GC/MS. A bio-oil fractionation method was successfully applied here. Results indicate that bio-oil viscosity decreases due to active sites on the zeolite framework. Active acids sites were associated with an increment of alcohols, aldehydes, and hydrocarbon content during storage. Higher composition on aldehydes and alcohols after storage could be attributed to the occurrence of carbonyl reduction reactions that promotes them. These reactions are influenced by zeolite surface characteristics and could be achieved via the direct contribution of Brønsted acid sites to Chilean natural zeolite.

  15. The influence of pyrolysis and matrix modifiers on determination of Cr and Pb in sediment samples by GFAAS

    Directory of Open Access Journals (Sweden)

    Risfidian Mohadi

    2016-04-01

    Full Text Available Abstract: The Influence of pyrolysis and matrix modifiers on determination of Cr and Pb in sediment samples using graphite furnace atomic absorption spectrometry has been investigated. The sediment samples including three certified reference materials (CRMs are reported. Analyses were performed using microwave assisted dissolution. The matrix modifiers Mg(NO32, Pd+Mg(NO32 and NH4H2PO4were shown to be optimazed. The recovery for Cr and Pb in CRMs in the case of sample dissolution was found to be between 81 to 91% for Cr and 94 to 98% for Pb of the certified values, respectively. Keywords: Sediment, Pyrolysis, Matrix modifiers, Cr, Pb Abstrak (Indonesia: Pengaruh pirolisis dan matriks pengubah pada penentuan Cr dan Pb dalam sampel sedimen menggunakan tungku grafit spektroskopi serapan atom telah diteliti. Sampel sedimen termasuk tiga bahan referensi bersertifikat (CRMs dilaporkan dianalisis dengan menggunakan bantuan microwave ekstraktor. Matriks pengubah Mg(NO32, Pd+Mg(NO32 dan NH4H2PO4 telah digunakan dan menghasilkan nilai temu balik untuk Cr dan Pb dalam CRMs ditemukan antara 81-91% untuk Cr dan 94-98 % untuk Pb dari nilai sertifikat masing-masing. Katakunci: Sedimen, Pirolisis, Matrix modifiers, Cr, Pb

  16. Fast Pyrolysis of Tropical Biomass Species and Influence of Water Pretreatment on Product Distributions.

    Science.gov (United States)

    Morgan, Trevor James; Turn, Scott Q; Sun, Ning; George, Anthe

    2016-01-01

    The fast pyrolysis behaviour of pretreated banagrass was examined at four temperatures (between 400 and 600 C) and four residence times (between ~1.2 and 12 s). The pretreatment used water washing/leaching to reduce the inorganic content of the banagrass. Yields of bio-oil, permanent gases and char were determined at each reaction condition and compared to previously published results from untreated banagrass. Comparing the bio-oil yields from the untreated and pretreated banagrass shows that the yields were greater from the pretreated banagrass by 4 to 11 wt% (absolute) at all reaction conditions. The effect of pretreatment (i.e. reducing the amount of ash, and alkali and alkali earth metals) on pyrolysis products is: 1) to increase the dry bio-oil yield, 2) to decrease the amount of undetected material, 3) to produce a slight increase in CO yield or no change, 4) to slightly decrease CO2 yield or no change, and 5) to produce a more stable bio-oil (less aging). Char yield and total gas yield were unaffected by feedstock pretreatment. Four other tropical biomass species were also pyrolyzed under one condition (450°C and 1.4 s residence time) for comparison to the banagrass results. The samples include two hardwoods: leucaena and eucalyptus, and two grasses: sugarcane bagasse and energy-cane. A sample of pretreated energy-cane was also pyrolyzed. Of the materials tested, the best feedstocks for fast pyrolysis were sugarcane bagasse, pretreated energy cane and eucalyptus based on the yields of 'dry bio-oil', CO and CO2. On the same basis, the least productive feedstocks are untreated banagrass followed by pretreated banagrass and leucaena.

  17. Fast Pyrolysis of Tropical Biomass Species and Influence of Water Pretreatment on Product Distributions.

    Directory of Open Access Journals (Sweden)

    Trevor James Morgan

    Full Text Available The fast pyrolysis behaviour of pretreated banagrass was examined at four temperatures (between 400 and 600 C and four residence times (between ~1.2 and 12 s. The pretreatment used water washing/leaching to reduce the inorganic content of the banagrass. Yields of bio-oil, permanent gases and char were determined at each reaction condition and compared to previously published results from untreated banagrass. Comparing the bio-oil yields from the untreated and pretreated banagrass shows that the yields were greater from the pretreated banagrass by 4 to 11 wt% (absolute at all reaction conditions. The effect of pretreatment (i.e. reducing the amount of ash, and alkali and alkali earth metals on pyrolysis products is: 1 to increase the dry bio-oil yield, 2 to decrease the amount of undetected material, 3 to produce a slight increase in CO yield or no change, 4 to slightly decrease CO2 yield or no change, and 5 to produce a more stable bio-oil (less aging. Char yield and total gas yield were unaffected by feedstock pretreatment. Four other tropical biomass species were also pyrolyzed under one condition (450°C and 1.4 s residence time for comparison to the banagrass results. The samples include two hardwoods: leucaena and eucalyptus, and two grasses: sugarcane bagasse and energy-cane. A sample of pretreated energy-cane was also pyrolyzed. Of the materials tested, the best feedstocks for fast pyrolysis were sugarcane bagasse, pretreated energy cane and eucalyptus based on the yields of 'dry bio-oil', CO and CO2. On the same basis, the least productive feedstocks are untreated banagrass followed by pretreated banagrass and leucaena.

  18. Low-temperature growth of highly crystallized transparent conductive fluorine-doped tin oxide films by intermittent spray pyrolysis deposition

    Energy Technology Data Exchange (ETDEWEB)

    Fukano, Tatsuo; Motohiro, Tomoyoshi [Toyota Central Research and Development Laboratories Inc., Nagakute, Aichi 480-1192 (Japan)

    2004-05-30

    Following the procedure by Sawada et al. (Thin Solid Films 409 (2002) 46), high-quality SnO{sub 2}:F films were grown on glass substrates at relatively low temperatures of 325-340C by intermittent spray pyrolysis deposition using a perfume atomizer for cosmetics use. Even though the substrate temperature is low, as-deposited films show a high optical transmittance of 92% in the visible range, a low electric resistivity of 5.8x10{sup -4}{omega}cm and a high Hall mobility of 28cm{sup 2}/Vs. The F/Sn atomic ratio (0.0074) in the films is low in comparison with the value (0.5) in the sprayed solution. The carrier density in the film is approximately equal to the F-ion density, suggesting that most of the F-ions effectively function as active dopants. Films' transmittance and resistivity show little change after a 450C 60min heat treatment in the atmosphere, evidencing a high heat resistance. The SnO{sub 2}:F films obtained in this work remove the difficulty to improve the figure of merit at low synthesis temperatures.

  19. Influence of the Zeolite ZSM-5 on Catalytic Pyrolysis of Biomass via TG-FTIR

    Directory of Open Access Journals (Sweden)

    Ze Wang

    2015-06-01

    Full Text Available Bio-oil from the pyrolysis of biomass is an important renewable source for liquid fuel. However, the application of bio-oil has been severely restricted due to its high viscosity, acidity, and low heating value. Thus, it has been necessary to upgrade bio-oil for automobile fuel via catalytic deoxygenation reactions. Herein, the effects of the zeolite ZSM-5 on the pyrolysis of four biomass materials (corn cob, corn straw, pine powder, and cellulose were investigated via TG-FTIR (thermogravimetric analyzer coupled with a Fourier transform infrared spectrometer to better understand the working mechanism of ZSM-5. The contents of the products of H2O, CO, CO2, and the C-O, C=O, and OH groups evolved with increasing pyrolytic temperature were monitored by FTIR. It was found that the relative contents of the C-O and C=O groups were decreased under the catalysis of ZSM-5, while the formations of CO, H2O, and the OH containing compounds were promoted. To explain the regulations, reaction routes were speculated and the catalytic conversion mechanisms were deduced.

  20. Electric plants to gas, influence of both Mineral Matter and Air Oxidation in coal pyrolysis

    International Nuclear Information System (INIS)

    Mondragon, F.; Jaramillo, A.; Quintero, G.

    1995-01-01

    In this work some coal samples from different Colombia's deposits are analyzed. In first stage, material matter is removed from coal by acid treatment with HF/HCl, and aerial oxidation of coal is made with air in oven to 150 Centigrade degree temperature. In second stage, pyrolysis is carried out in two different techniques: 1. Thermogravimetric Analysis (TGA) and 2. Programmed Temperature Pyrolysis (PTP) in a pyrolyzer equipped with a quadrupole mass spectrometer. In both techniques, the coal samples are heated in different rates to 650 Centigrade degree. During PTP trials the evolution of CH4, H2S, hydrocarbons (m/z=42), CO2, benzene and toluene are monitored. Studied coal samples showed: 1). A gas conversion range between 48.8% to 21.8%; 2). A decrease in the gas conversion between 2% to 4%, when oxidation it is applied; 3). The temperature at the one which is presented the maximum evolution of CH4 is similar for all coal samples; 4). The maximum evolution of H2S depends on mineral matter composition, occurs between 480 to 550 Centigrade degrees and is presented due to pyrite decomposition. 5). The evolution of CO2 occurs between 100 to 650 Centigrade degree, its production is generated in different stage of the mentioned temperature range, and in some coal samples is presented due to inorganic origin

  1. Improvement of Transparent Conducting Performance on Oxygen-Activated Fluorine-Doped Tin Oxide Electrodes Formed by Horizontal Ultrasonic Spray Pyrolysis Deposition.

    Science.gov (United States)

    Koo, Bon-Ryul; Oh, Dong-Hyeun; Riu, Doh-Hyung; Ahn, Hyo-Jin

    2017-12-27

    In this study, highly transparent conducting fluorine-doped tin oxide (FTO) electrodes were fabricated using the horizontal ultrasonic spray pyrolysis deposition. In order to improve their transparent conducting performances, we carried out oxygen activation by adjusting the ratio of O 2 /(O 2 +N 2 ) in the carrier gas (0%, 20%, and 50%) used during the deposition process. The oxygen activation on the FTO electrodes accelerated the substitution concentration of F (F O • ) into the oxygen sites in the FTO electrode while the oxygen vacancy (V O • • ) concentration was reduced. In addition, due to growth of pyramid-shaped crystallites with (200) preferred orientations, this oxygen activation caused the formation of a uniform surface structure. As a result, compared to others, the FTO electrode prepared at 50% O 2 showed excellent electrical and optical properties (sheet resistance of ∼4.0 ± 0.14 Ω/□, optical transmittance of ∼85.3%, and figure of merit of ∼5.09 ± 0.19 × 10 -2 Ω -1 ). This led to a superb photoconversion efficiency (∼7.03 ± 0.20%) as a result of the improved short-circuit current density. The photovoltaic performance improvement can be defined by the decreased sheet resistance of FTO used as a transparent conducting electrode in dye-sensitized solar cells (DSSCs), which is due to the combined effect of the high carrier concentration by the improved F O • concentration on the FTO electrodes and the fasted Hall mobility by the formation of a uniform FTO surface structure and distortion relaxation on the FTO lattices resulting from the reduced V O • • • concentration.

  2. Characterization of Lanthanum Ferric Cobaltite doped with Strontium (LSCF) films deposited by spray-pyrolysis for application as cathode in PaCOS-TI; Caracterizacao de filmes de CFLE depositados por spray-pirolise para utilizacao como catodo em PaCOS-TI

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, L.S.; Guimaraes, V.F.; Paes Junior, H.R. [Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, RJ (Brazil). Lab. de Materiais Avancados], Emails: laryssadsa@yahoo.com.br, valtencyguimaraes@yahoo.com.br, herval@uenf.br

    2010-07-01

    The lanthanum ferric cobaltite doped with strontium (LSCF) is a ceramic material with the perovskite structure that stands out in the field of research for its use as cathode in solid oxide fuel cells at intermediate temperatures (IT-SOFC). The films were synthesized by spray-pyrolysis technique on 8% mol Yttria stabilized zirconia (YSZ) substrates. It was studied the influence of heat treatment temperatures (600-1000 deg C) on the properties of the films under the conditions of treatment during four hours. Samples were tested electrically by measuring the variation of electrical conductivity with temperature, structurally by X-ray diffraction (XRD) and morphologically by scanning electron microscopy (SEM). The films heat treated at 700 deg C for 4 hours showed better performance for application as cathode. (author)

  3. Fluidized bed pyrolysis of HDPE: A study of the influence of operating variables and the main fluid dynamic parameters on the composition and production of gases

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Lidia; Aguado, Alicia; Moral, Alberto [CARTOF Centro Tecnologico, Valladolid (Spain). Environmental Div.; Irusta, Ruben [CARTOF Centro Tecnologico, Valladolid (Spain). Environmental Div.; Valladolid Univ. (Spain). Dept. of Chemical Engineering and Environmental Technology

    2011-02-15

    In the present work, a preliminary study of the pyrolysis process of high density polyethylene (HDPE) in a fluidized bed is investigated in order to determine the influence between the fluid dynamic properties of the bed reactor and the amount and composition of the gases produced. As is known, fluidized bed technology is a very interesting option to apply in the pyrolysis field due to i) the lack of moving parts in the hot region that facilitates the maintenance of equipment, ii) the high surface area to volume ratio available in the bed, and iii) the high heat transfer coefficient reached which governs the reaction products. But, heat and mass transfer coefficients are strongly affected by the fluid dynamic properties of the bed. During the pyrolysis of HDPE, a fluid dynamic characterization of the bed particles that consist of char-coated sand of HDPE has been carried out. Parameters such as the minimum fluidizing velocity (u{sub mf}), terminal velocity (u{sub t}), bed height (h{sub f}), bed voidage ({epsilon}{sub f}), fraction of the bed occupied by bubbles ({delta}), bubble diameter (d{sub b}), bubble velocity (u{sub b}), the mass transfer coefficients between the bubble and the cloud (K{sub bc}) and between the cloud and the emulsion (K{sub ce}) were determined. Subsequently, the influence of major operating variables and the fluid dynamic parameters on the composition and the gas yield of the pyrolysis of HDPE were studied. (author)

  4. Effect of pre-pyrolysis mode on simultaneous introduction of nitrogen/oxygen-containing functional groups into the structure of bagasse-based mesoporous carbon and its influence on Cu(II) adsorption.

    Science.gov (United States)

    Wan, Zeqing; Li, Kunquan

    2018-03-01

    A convenient effective microwave pre-pyrolysis treatment to synthesize biomass-based mesoporous carbon with higher nitrogen/oxygen-chelating adsorption for Cu(II) is reported here, in which phosphoric acid impregnated bagasse was used as a microwave absorber and porogen. For comparison, conventional electric-heating pyrolyzed carbon was prepared and doped with nitrogen/oxygen groups. Nitrogen adsorption, scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy (XPS) and batch adsorption were employed to investigate the effects of the two pre-pyrolysis modes on the sample physicochemical and Cu(II) adsorptive properties. The 22-min-microwave-pyrolyzed bagasse mesoporous activated carbon (MBAC, 85.32% mesoporosity) contained 10.52% O, which is 3.94% more than electric-heating pyrolyzed mesoporous activated carbon (89.52% mesoporosity). After electrophilic aromatic substitutions of N/O doping, the former possessed more N (5.83%) and more O (21.40%), confirming that time-saving energy-efficient microwave pyrolysis favors the formation of defective C/O atoms in or at the edges of the graphite layer of MBAC, which are highly active and tend to act as preferred reactive positions for the doping of N/O-containing groups simultaneously compared with conventional electric-heating pyrolysis. These N and O species existed mainly as COOH, OH, NH and NH 2 functional groups, and were confirmed by XPS to be active sites for metal binding via electrostatic attraction, hydrogen bonding, a chelate effect and complexation, resulting in the great enhancement of Cu(II) adsorption. Langmuir isotherm and pseudo-second-order kinetic fitting further proved that Cu(II) adsorption by N/O-doped MBAC is ascribed mainly to chemisorption. Therefore, rapid microwave pre-pyrolysis provides a promising route to prepare excellent-performance N/O-doped carbon adsorbents. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Influence of doping location and width of dimethylquinacridone on the performance of organic light emitting devices

    International Nuclear Information System (INIS)

    Li Jingze; Yahiro, Masayuki; Ishida, Kenji; Matsushige, Kazumi

    2005-01-01

    The influence of doping location and width of fluorescent dimethylquinacridone (DMQA) molecules on the performance of organic light emitting devices has been systematically investigated. While the doped zone is located at the interface of the hole transport layer (HTL) and the light emitting layer (EML), doping in the HTL leads to significant improvement of the external quantum efficiency relative to the undoped device, whereas the efficiency is lower than that of doping in the EML. This phenomenon is explained according to the electroluminescence (EL) process of the doped DMQA, which is dominated by Foerster energy transfer. Additionally, a device with dual doping in both HTL and EML exhibits the highest efficiency. The EL and photoluminescence spectra are also dependent on the doping sites

  6. Influence of Pyrolysis Temperature on Physico-Chemical Properties of Corn Stover (Zea mays L. Biochar and Feasibility for Carbon Capture and Energy Balance.

    Directory of Open Access Journals (Sweden)

    Muhammad Khalid Rafiq

    Full Text Available This study examined the influence of pyrolysis temperature on biochar characteristics and evaluated its suitability for carbon capture and energy production. Biochar was produced from corn stover using slow pyrolysis at 300, 400 and 500°C and 2 hrs holding time. The experimental biochars were characterized by elemental analysis, BET, FTIR, TGA/DTA, NMR (C-13. Higher heating value (HHV of feedstock and biochars was measured using bomb calorimeter. Results show that carbon content of corn stover biochar increased from 45.5% to 64.5%, with increasing pyrolysis temperatures. A decrease in H:C and O:C ratios as well as volatile matter, coupled with increase in the concentration of aromatic carbon in the biochar as determined by FTIR and NMR (C-13 demonstrates a higher biochar carbon stability at 500°C. It was estimated that corn stover pyrolysed at 500°C could provide of 10.12 MJ/kg thermal energy. Pyrolysis is therefore a potential technology with its carbon-negative, energy positive and soil amendment benefits thus creating win- win scenario.

  7. Influence of Pyrolysis Temperature on Physico-Chemical Properties of Corn Stover (Zea mays L.) Biochar and Feasibility for Carbon Capture and Energy Balance.

    Science.gov (United States)

    Rafiq, Muhammad Khalid; Bachmann, Robert Thomas; Rafiq, Muhammad Tariq; Shang, Zhanhuan; Joseph, Stephen; Long, Ruijun

    2016-01-01

    This study examined the influence of pyrolysis temperature on biochar characteristics and evaluated its suitability for carbon capture and energy production. Biochar was produced from corn stover using slow pyrolysis at 300, 400 and 500°C and 2 hrs holding time. The experimental biochars were characterized by elemental analysis, BET, FTIR, TGA/DTA, NMR (C-13). Higher heating value (HHV) of feedstock and biochars was measured using bomb calorimeter. Results show that carbon content of corn stover biochar increased from 45.5% to 64.5%, with increasing pyrolysis temperatures. A decrease in H:C and O:C ratios as well as volatile matter, coupled with increase in the concentration of aromatic carbon in the biochar as determined by FTIR and NMR (C-13) demonstrates a higher biochar carbon stability at 500°C. It was estimated that corn stover pyrolysed at 500°C could provide of 10.12 MJ/kg thermal energy. Pyrolysis is therefore a potential technology with its carbon-negative, energy positive and soil amendment benefits thus creating win- win scenario.

  8. Influence of distillation on performance, emission, and combustion of a DI diesel engine, using tyre pyrolysis oil diesel blends

    Directory of Open Access Journals (Sweden)

    Murugan Sivalingam

    2008-01-01

    Full Text Available Conversion of waste to energy is one of the recent trends in minimizing not only the waste disposal but also could be used as an alternate fuel for internal combustion engines. Fuels like wood pyrolysis oil, rubber pyrolysis oil are also derived through waste to energy conversion method. Early investigations report that tyre pyrolysis oil derived from vacuum pyrolysis method seemed to possess properties similar to diesel fuel. In the present work, the crude tyre pyrolisis oil was desulphurised and distilled to improve the properties and studied the use of it. Experimental studies were conducted on a single cylinder four-stroke air cooled engine fuelled with two different blends, 30% tyre pyrolysis oil and 70% diesel fuel (TPO 30 and 30% distilled tyre pyrolysis oil and 70% diesel fuel (DTPO 30. The results of the performance, emission and combustion characteristics of the engine indicated that NOx is reduced by about 8% compared to tire pyrolysis oil and by about 10% compared to diesel fuel. Hydrocarbon emission is reduced by about 2% compared to TPO 30 operation. Smoke increased for DTPO 30 compared to TPO 30 and diesel fuel.

  9. Influence of solution deposition rate on properties of V_2O_5 thin films deposited by spray pyrolysis technique

    International Nuclear Information System (INIS)

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

    2016-01-01

    Vanadium oxide (V_2O_5) 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 VCl_3 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 V_2O_5 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).

  10. Influence of La Doping on Magnetic and Optical Properties of Bismuth Ferrite Nanofibers

    Directory of Open Access Journals (Sweden)

    Ziang Zhang

    2012-01-01

    Full Text Available The influence of La doping on the crystal structure, ferromagnetic, and optical properties of BFO nanofibers was investigated. Bi1−xLaxFeO3 ultrafine nanofibers were synthesized by the electrospinning method. The surface morphology and crystal structure of the as-spun and sintered fibers were not affected by the doping. The impurity phases of the BFO crystals were weakened with the increment of La concentration. The magnetization field curves showed that the magnetization weakened under low La doping proportion, but strengthened with the increase of the doped proportion. The magnetization curves also showed continuous strong enhancement of ferromagnetic behavior. The results of UV-vis and photoabsorption testing revealed little influence of La doping on the optical property.

  11. Sonochemically synthesized iron-doped zinc oxide nanoparticles: Influence of precursor composition on characteristics

    International Nuclear Information System (INIS)

    Roy, Anirban; Maitra, Saikat; Ghosh, Sobhan; Chakrabarti, Sampa

    2016-01-01

    Highlights: • Sonochemical synthesis of iron-doped zinc oxide nanoparticles. • Green synthesis without alkali at room temperature. • Characterization by UV–vis spectroscopy, FESEM, XRD and EDX. • Influence of precursor composition on characteristics. • Composition and characteristics are correlated. - Abstract: Iron-doped zinc oxide nanoparticles have been synthesized sonochemically from aqueous acetyl acetonate precursors of different proportions. Synthesized nanoparticles were characterized with UV–vis spectroscopy, X-ray diffraction and microscopy. Influences of precursor mixture on the characteristics have been examined and modeled. Linear correlations have been proposed between dopant dosing, extent of doping and band gap energy. Experimental data corroborated with the proposed models.

  12. Pyrolysis of Pinus pinaster in a two-stage gasifier: Influence of processing parameters and thermal cracking of tar

    Energy Technology Data Exchange (ETDEWEB)

    Fassinou, Wanignon Ferdinand; Toure, Siaka [Laboratoire d' Energie Solaire-UFR-S.S.M.T. Universite de Cocody, 22BP582 Abidjan 22 (Ivory Coast); Van de Steene, Laurent; Volle, Ghislaine; Girard, Philippe [CIRAD-Foret, TA 10/16, 73, avenue J.-F. Breton, 34398 Montpellier, Cedex 5 (France)

    2009-01-15

    A new two-stage gasifier with fixed-bed has recently been installed on CIRAD facilities in Montpellier. The pyrolysis and the gasifier units are removable. In order to characterise the pyrolysis products before their gasification, experiments were carried out, for the first time only with the pyrolysis unit and this paper deals with the results obtained. The biomass used is Pinus pinaster. The parameters investigated are: temperature, residence time and biomass flow rate. It has been found that increasing temperature and residence time improve the cracking of tars, gas production and char quality (fixed carbon rate more than 90%, volatile matter rate less than 4%). The increase of biomass flow rate leads to a bad char quality. The efficiency of tar cracking, the quality and the heating value of the charcoal and the gases, indicate that: temperature between 650 C and 750 C, residence time of 30 min, biomass flow rate between 10 and 15 kg/h should be the most convenient experimental conditions to get better results from the experimental device and from the biomass pyrolysis process. The kinetic study of charcoal generation shows that the pyrolysis process, in experimental conditions, is a first-order reaction. The kinetic parameters calculated are comparable with those found by other researchers. (author)

  13. The influence of Fe doping on the surface topography of GaN epitaxial material

    International Nuclear Information System (INIS)

    Cui Lei; Yin Haibo; Jiang Lijuan; Wang Quan; Feng Chun; Xiao Hongling; Wang Cuimei; Wang Xiaoliang; Gong Jiamin; Zhang Bo; Li Baiquan; Wang Zhanguo

    2015-01-01

    Fe doping is an effective method to obtain high resistivity GaN epitaxial material. But in some cases, Fe doping could result in serious deterioration of the GaN material surface topography, which will affect the electrical properties of two dimensional electron gas (2DEG) in HEMT device. In this paper, the influence of Fe doping on the surface topography of GaN epitaxial material is studied. The results of experiments indicate that the surface topography of Fe-doped GaN epitaxial material can be effectively improved and the resistivity could be increased after increasing the growth rate of GaN materials. The GaN material with good surface topography can be manufactured when the Fe doping concentration is 9 × 10 19 cm −3 . High resistivity GaN epitaxial material which is 1 × 10 9 Ω·cm is achieved. (paper)

  14. Influence of Rare Earth Doping on the Structural and Catalytic Properties of Nanostructured Tin Oxide

    Directory of Open Access Journals (Sweden)

    Maciel Adeilton

    2008-01-01

    Full Text Available AbstractNanoparticles of tin oxide, doped with Ce and Y, were prepared using the polymeric precursor method. The structural variations of the tin oxide nanoparticles were characterized by means of nitrogen physisorption, carbon dioxide chemisorption, X-ray diffraction, and X-ray photoelectron spectroscopy. The synthesized samples, undoped and doped with the rare earths, were used to promote the ethanol steam reforming reaction. The SnO2-based nanoparticles were shown to be active catalysts for the ethanol steam reforming. The surface properties, such as surface area, basicity/base strength distribution, and catalytic activity/selectivity, were influenced by the rare earth doping of SnO2and also by the annealing temperatures. Doping led to chemical and micro-structural variations at the surface of the SnO2particles. Changes in the catalytic properties of the samples, such as selectivity toward ethylene, may be ascribed to different dopings and annealing temperatures.

  15. Influence of iron doping on tetravalent nickel content in catalytic oxygen evolving films

    Energy Technology Data Exchange (ETDEWEB)

    Li, Nancy; Bediako, D. Kwabena; Hadt, Ryan G.; Hayes, Dugan; Kempa, Thomas J.; von Cube, Felix; Bell, David C.; Chen, Lin X.; Nocera, Daniel G.

    2017-01-30

    Iron doping of nickel oxide films results in enhanced activity for promoting the oxygen evolution reaction (OER). Whereas this enhanced activity has been ascribed to a unique iron site within the nickel oxide matrix, we show here that Fe doping influences the Ni valency. The percent of Fe3+ doping promotes the formation of formal Ni4+, which in turn directly correlates with an enhanced activity of the catalyst in promoting OER. The role of Fe3+ is consistent with its behavior as a superior Lewis acid.

  16. Thermal and catalytic pyrolysis of plastic waste

    Directory of Open Access Journals (Sweden)

    Débora Almeida

    2016-02-01

    Full Text Available Abstract The amount of plastic waste is growing every year and with that comes an environmental concern regarding this problem. Pyrolysis as a tertiary recycling process is presented as a solution. Pyrolysis can be thermal or catalytical and can be performed under different experimental conditions. These conditions affect the type and amount of product obtained. With the pyrolysis process, products can be obtained with high added value, such as fuel oils and feedstock for new products. Zeolites can be used as catalysts in catalytic pyrolysis and influence the final products obtained.

  17. Influence of biochar pyrolysis temperature and post-treatment on the uptake of mercury from flue gas

    Science.gov (United States)

    Thermal processing, or pyrolysis, of plant and animal waste under oxygen limiting conditions results in a carbonized material called biochar. Most often, the proposed application for the biochar is soil applications as a conditioner or for the purpose of carbon sequestration. In this paper we demons...

  18. Influence of texture coefficient on surface morphology and sensing properties of W-doped nanocrystalline tin oxide thin films.

    Science.gov (United States)

    Kumar, Manjeet; Kumar, Akshay; Abhyankar, A C

    2015-02-18

    For the first time, a new facile approach based on simple and inexpensive chemical spray pyrolysis (CSP) technique is used to deposit Tungsten (W) doped nanocrystalline SnO2 thin films. The textural, optical, structural and sensing properties are investigated by GAXRD, UV spectroscopy, FESEM, AFM, and home-built sensing setup. The gas sensing results indicate that, as compared to pure SnO2, 1 wt % W-doping improves sensitivity along with better response (roughness values of 3.82 eV and 3.01 nm, respectively. Reduction in texture coefficient along highly dense (110) planes with concomitant increase along loosely packed (200) planes is found to have prominent effect on gas sensing properties of W-doped films.

  19. A facile method to synthesize nitrogen and fluorine co-doped TiO{sub 2} nanoparticles by pyrolysis of (NH{sub 4}){sub 2}TiF{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Chen Daimei; Jiang Zhongyi; Geng Jiaqing; Zhu Juhong; Yang Dong, E-mail: dyangdong@hotmail.co [Tianjin University, Key Laboratory for Green Chemical Technology, School of Chemical Engineering and Technology (China)

    2009-02-15

    The nitrogen and fluorine co-doped TiO{sub 2} (N-F-TiO{sub 2}) nanoparticles of anatase crystalline structure were prepared by a facile method of (NH{sub 4}){sub 2}TiF{sub 6} pyrolysis, and characterized by thermogravimetry-differential thermal analysis (TG-DTA), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and ultraviolet visible (UV-Vis) spectroscopy etc. With the increase of calcination temperature, (NH{sub 4}){sub 2}TiF{sub 6} decomposed into TiOF{sub 2} and NH{sub 4}TiOF{sub 3} at first, and then formed anatase-type TiO{sub 2} with thin sheet morphology. H{sub 3}BO{sub 3} as oxygen source can promote the formation of anatase TiO{sub 2}, but decrease the F content in the N-F-TiO{sub 2} materials due to the formation of volatile BF{sub 3} during the precursor decomposition. The photocatalytic activity of the obtained N-F-TiO{sub 2} samples was evaluated by the methylene blue degradation under visible light, and all the samples exhibited much higher photocatalytic activity than P25. Moreover, the merits and disadvantages of this proposed method to prepare doped TiO{sub 2} are discussed.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    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.

  1. Bitumen pyrolysis

    International Nuclear Information System (INIS)

    Braehler, G.; Noll, T.

    2014-01-01

    In the past bitumen was a preferred matrix for the embedding of low and intermediate level radioactive waste: its geological history promised long term stability in final repositories. A great variety of waste has been embedded: technological waste, spent ion exchange resins, concrete, rubble, etc. Liquid waste like evaporator concentrates can be dried and embedded simultaneously in extruders, allowing simple processes and equipment. Unfortunately, during long term intermediate storage the bituminized waste drums proved out being not as stable as expected: a significant number turned out to be no longer acceptable for final disposal, and some of them even needed repacking to enable further intermediate storage. A method to rework such drums with bituminized radioactive waste seems to be urgently needed. Pyrolysis and pyro-hydrolysis (= pyrolysis with water steam added) have a long history for the treatment of organic waste: spent solvent (TBP), spent ion exchange resins, alpha waste (predominantly PVC), etc. Due to its low process temperature and the endothermic character, such processes offer significant safety advantages, as compared to incineration or dissolving in organic solvents. Results of lab-scale investigations and concepts for facilities are presented. (authors)

  2. Influence of different ions doping on the antibacterial properties of MgO nanopowders

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Yuanyuan; Wang, Wei, E-mail: weiwang@hust.edu.cn; Tan, Fatang; Cai, Yuncheng; Lu, Junwen; Qiao, Xueliang

    2013-11-01

    Compared with other inorganic antibacterial agents, magnesium oxide (MgO) nanopowders exhibit a unique antibacterial mechanism and various advantages in applications, having attracted extensive attention. In this study, MgO nanopowders doped with different ions (Li{sup +}, Zn{sup 2+} and Ti{sup 4+}) were synthesized by a sol–gel method, respectively. The structures and morphologies of the as-obtained precursors and nanopowders were characterized and confirmed by X-ray diffraction (XRD), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS) analysis. The influence of three metal ions doping on the antibacterial properties of MgO nanopowders was also investigated by their bactericidal activity against Escherichia coli (E. coli, ATCC 25922) using the broth microdilution method and the agar method. The results show that Li-doped MgO exhibits better antibacterial activity, Zn-doped and Ti-doped MgO display poorer antibacterial activity than pure MgO. It can be concluded that the influence of different ions doping on the antibacterial properties of MgO mainly lies on oxygen vacancies and basicity of nanopowders.

  3. Orientation-dependent low field magnetic anomalies and room-temperature spintronic material – Mn doped ZnO films by aerosol spray pyrolysis

    CSIR Research Space (South Africa)

    Nkosi, SS

    2013-12-01

    Full Text Available of ferromagnetism, a relatively new phenomenon called “low-field microwave absorption” has been observed in ferromagnetic materials and other various materials such as high temperature superconductors, ferrites, manganites, doped silicate glasses and soft... absorption phenomenon has been observed in ferromagnetic materials and various other materials such as superconductors, ferrites, manganites, semiconductors, doped silicate glasses, in soft materials and recently in iron monosilicides films [41- 46...

  4. Influence of Ag thickness of aluminum-doped ZnO/Ag/aluminum-doped ZnO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Hung-Wei, E-mail: hwwu@mail.ksu.edu.tw [Department of Computer and Communication, Kun Shan University, No. 949, Dawan Rd., Yongkang Dist., Tainan City 710, Taiwan (China); Yang, Ru-Yuan [Graduate Institute of Materials Engineering, National Pingtung University of Science and Technology, 1, Shuefu Rd., Neipu, Pingtung City 912, Taiwan (China); Hsiung, Chin-Min; Chu, Chien-Hsun [Department of Mechanical Engineering, National Pingtung University of Science and Technology, 1, Shuefu Rd., Neipu, Pingtung City 912, Taiwan (China)

    2012-10-01

    Highly conducting aluminum-doped ZnO (30 nm)/Ag (5-15 nm)/aluminum-doped ZnO (30 nm) multilayer thin films were deposited on glass substrate by rf magnetron sputtering (for top/bottom aluminum-doped ZnO films) and e-beam evaporation (for Ag film). The transmittance is more than 70% for wavelengths above 400 nm with the Ag layer thickness of 10 nm. The resistivity is 3.71 Multiplication-Sign 10{sup -4} {Omega}-cm, which can be decreased to 3.8 Multiplication-Sign 10{sup -5} {Omega}-cm with the increase of the Ag layer thickness to 15 nm. The Haacke figure of merit has been calculated for the films with the best value being 8 Multiplication-Sign 10{sup -3} {Omega}{sup -1}. It was shown that the multilayer thin films have potential for applications in optoelectronics. - Highlights: Black-Right-Pointing-Pointer High-quality Al-doped ZnO (AZO)/Ag/AZO Transparent Conducting Oxide films. Black-Right-Pointing-Pointer AZO films (30 nm) made by RF sputtering; E-beam evaporation for Ag film (5-15 nm). Black-Right-Pointing-Pointer Influence of Ag thickness on optical and electrical properties were analyzed. Black-Right-Pointing-Pointer High quality multilayer film with optimal intermediate Ag layer thickness of 10 nm. Black-Right-Pointing-Pointer 3.71 Multiplication-Sign 10{sup -4} {Omega}-cm resistivity, 91.89% transmittance at 470 nm obtained and reproducible.

  5. Catalytic Hydrodeoxygenation of Biomass Pyrolysis Vapor Model Compounds over Molybdenum Sulfide Catalysts: Influence of Support, H2S and Water

    DEFF Research Database (Denmark)

    Arndal, Trine Marie Hartmann; Høj, Martin; Pintos, Delfina Garcia

    value, acidity and stability [1,2]. Upgrading ofcondensed pyrolysis oil is challenged by severe polymerization and coking upon heating. Instead, it is proposed toperform pyrolysis in the presence of hydrogen and an HDO catalyst for immediate stabilization and upgrading ofreactive pyrolysis products...

  6. Influence of silica-alumina support ratio on H2 production and catalyst carbon deposition from the Ni-catalytic pyrolysis/reforming of waste tyres.

    Science.gov (United States)

    Zhang, Yeshui; Tao, Yongwen; Huang, Jun; Williams, Paul

    2017-10-01

    The influence of catalyst support alumina-silica in terms of different Al 2 O 3 to SiO 2 mole ratios containing 20 wt.% Ni on the production of hydrogen and catalyst coke formation from the pyrolysis-catalysis of waste tyres is reported. A two-stage reactor system was used with pyrolysis of the tyres followed by catalytic reaction. There was only a small difference in the total gas yield and hydrogen yield by changing the Al 2 O 3 to SiO 2 mole ratios in the Ni-Al 2 O 3 /SiO 2 catalyst. The 1:1 ratio of Al 2 O 3 :SiO 2 ratio produced the highest gas yield of 27.3 wt.% and a hydrogen production of 14.0 mmol g -1 tyre . Catalyst coke formation decreased from 19.0 to 13.0 wt.% as the Al 2 O 3 :SiO 2 ratio was changed from 1:1 to 2:1, with more than 95% of the coke being filamentous-type carbon, a large proportion of which was multi-walled carbon nanotubes. Further experiments introduced steam to the second-stage reactor to investigate hydrogen production for the pyrolysis-catalytic steam reforming of the waste tyres using the 1:1 Al 2 O 3 /SiO 2 nickel catalyst. The introduction of steam produced a marked increase in total gas yield from ~27 wt. % to ~58 wt.%; in addition, hydrogen production was increased to 34.5 mmol g -1 and there was a reduction in catalyst coke formation to 4.6 wt.%.

  7. Influence of silica–alumina support ratio on H2 production and catalyst carbon deposition from the Ni-catalytic pyrolysis/reforming of waste tyres

    Science.gov (United States)

    Zhang, Yeshui; Tao, Yongwen; Huang, Jun; Williams, Paul

    2017-01-01

    The influence of catalyst support alumina–silica in terms of different Al2O3 to SiO2 mole ratios containing 20 wt.% Ni on the production of hydrogen and catalyst coke formation from the pyrolysis-catalysis of waste tyres is reported. A two-stage reactor system was used with pyrolysis of the tyres followed by catalytic reaction. There was only a small difference in the total gas yield and hydrogen yield by changing the Al2O3 to SiO2 mole ratios in the Ni-Al2O3/SiO2 catalyst. The 1:1 ratio of Al2O3:SiO2 ratio produced the highest gas yield of 27.3 wt.% and a hydrogen production of 14.0 mmol g-1tyre. Catalyst coke formation decreased from 19.0 to 13.0 wt.% as the Al2O3:SiO2 ratio was changed from 1:1 to 2:1, with more than 95% of the coke being filamentous-type carbon, a large proportion of which was multi-walled carbon nanotubes. Further experiments introduced steam to the second-stage reactor to investigate hydrogen production for the pyrolysis-catalytic steam reforming of the waste tyres using the 1:1 Al2O3/SiO2 nickel catalyst. The introduction of steam produced a marked increase in total gas yield from ~27 wt. % to ~58 wt.%; in addition, hydrogen production was increased to 34.5 mmol g-1 and there was a reduction in catalyst coke formation to 4.6 wt.%. PMID:28789599

  8. Microstructural and electrical characterizations of tungsten-doped La2Mo2O9 prepared by spray pyrolysis

    DEFF Research Database (Denmark)

    Baqué, Laura; Vega-Castillo, Jesús; Georges, Samuel

    2013-01-01

    La2Mo2 − xWxO9 (x=0, 0.5, 1.0, and 1.3) nanocrystalline powders were synthesized by spray pyrolysis (SP) assisted by an ultrasonic atomizer. Microstructure, sinterability and thermal stability of the prepared powders were investigated. Spherical particles of 430 to 530 nm in diameter and crystall......La2Mo2 − xWxO9 (x=0, 0.5, 1.0, and 1.3) nanocrystalline powders were synthesized by spray pyrolysis (SP) assisted by an ultrasonic atomizer. Microstructure, sinterability and thermal stability of the prepared powders were investigated. Spherical particles of 430 to 530 nm in diameter...... by applying different sintering programs starting from La2Mo2 − xWxO9 powders (x=0 and 1.3) obtained by SP and SSR processes. The electrical properties of these ionic conductors were analyzed by Electrochemical Impedance Spectroscopy (EIS) and correlated with microstructural observations. No significant...... variation of the electrical properties of these ionic conductors was found as compared to conventional ceramics with remarkable microstructural differences....

  9. Influence of pyrolysis temperature on fracture response in SiOC based composites reinforced by basalt woven fabric

    Czech Academy of Sciences Publication Activity Database

    Chlup, Zdeněk; Černý, Martin; Strachota, Adam; Sucharda, Zbyněk; Halasová, Martina; Dlouhý, Ivo

    2014-01-01

    Roč. 34, č. 14 (2014), s. 3389-3398 ISSN 0955-2219 R&D Projects: GA ČR GAP107/12/2445; GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081723 ; RVO:67985891 ; RVO:61389013 Keywords : Fracture behaviour * CMCs * Pyrolysis * Basalt fibre * Polysiloxane Subject RIV: JL - Materials Fatigue, Friction Mechanics; JI - Composite Materials (USMH-B); JH - Ceramics, Fire-Resistant Materials and Glass (UMCH-V) Impact factor: 2.947, year: 2014

  10. Effect of Al-doped on physical properties of ZnO Thin films grown by spray pyrolysis on SnO2: F/glass

    Directory of Open Access Journals (Sweden)

    Castagné M.

    2012-06-01

    Full Text Available Transparent conducting thin films of aluminum-doped zinc oxide (ZnO:Al have been deposited on SnO2:F/glass by the chemical spray technique, starting from zinc acetate (CH3CO22Zn.2H2O and aluminum chloride AlCl3. The effect of changing the aluminum-to-zinc ratio y from 0 to 3 at.%, has been thoroughly investigated. It was found that the optical and electrical properties of Al doped ZnO films improved with the addition of aluminum in the spray solution until y=2%. At this Al doping percentage, the thin layers have a resistivity equal to 4.1 × 10−4 Ω.cm and a transmittance of about 90 % in the region [600-1000] nm. XRD patterns confirm that the films have polycristalline nature and a wurtzite (hexagonal structure which characterized with (100, (002 and (101 principal orientations. The undoped films have (002 as the preferred orientation but Al doped ones have (101 as the preferred orientation. Beyond y= 1%, peak intensities decrease considerably.

  11. The influence of ytterbium doping on the optical properties of tellurite glasses

    Energy Technology Data Exchange (ETDEWEB)

    Jaglarz, Janusz; Burtan, Bozena [Institute of Physics, Cracow University of Technology, ul. Podchorazych 1, 30-084 Cracow (Poland); Reben, Manuela; Wasylak, Jan [Faculty of Materials Science and Ceramics, AGH - University of Science and Technology, al. Mickiewicza 30, 30-059 Cracow (Poland); Cisowski, Jan [Institute of Physics, Cracow University of Technology, ul. Podchorazych 1, 30-084 Cracow (Poland); Centre of Polymer and Carbon Materials, Polish Academy of Sciences, ul. M. Curie-Sklodowskiej 34, 41-819 Zabrze (Poland); Jarzabek, Bozena [Centre of Polymer and Carbon Materials, Polish Academy of Sciences, ul. M. Curie-Sklodowskiej 34, 41-819 Zabrze (Poland)

    2011-09-15

    The goal of this work was to investigate the influence of rare earth ion Yb{sup 3+} doping on the thermal and optical properties of tellurite glass (TG) of the TeO{sub 2}-ZnO-PbO-La{sub 2}O{sub 3} system. The reflectance, transmittance and ellipsometric measurements have been done. Decreasing of the refractive index of TG with the Yb{sup 3+} ion doping has been concluded. For determination of the refractive index variation in the bulk, the small angle light scatter (SALS) measurements have been carried out. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  12. Fabrication of 10%Gd-doped ceria (GDC)/NiO-GDC half cell for low or intermediate temperature solid oxide fuel cells using spray pyrolysis

    DEFF Research Database (Denmark)

    Chourashiya, M. G.; Bhardwaj, S. R.; Jadhav, L. D.

    2010-01-01

    temperature SOFCs. Additionally, if GDC is employed in thin film form, rather higher ionic conductivity at further lower temperatures can be obtained and thereby allowing its use in low temperature SOFC. In the present investigation, the preparative parameters of spray pyrolysis technique (SPT) were optimized...... SEM observations of post heat-treated (at 1,000 °C) GDC/NiO-GDC structure revealed that GDC films were uniform in thickness with improved adherence to substrate. The relative density of post heat-treated films was of the order of 96%, which was attributed to the presence of nano-granules in the thin...... to deposit dense and adherent films of GDC on ceramic substrate. NiO-GDC was used as ceramic substrate, which also acts as a precursor composite anode for GDC-based SOFCs. Prepared half cells (GDC/NiO-GDC) were characterized using XRD, SEM, and electrochemical impedance spectroscopy. The surface and fractal...

  13. The catalytic cracking mechanism of lignite pyrolysis char on tar

    International Nuclear Information System (INIS)

    Lei, Z.; Huibin, H.; Xiangling, S.; Zhenhua, M.; Lei, Z.

    2017-01-01

    The influence of different pyrolysis conditions for tar catalytic cracking will be analyzed according to the lignite pyrolysis char as catalyst on pyrolytic tar in this paper. The pyrolysis char what is the by-product of the cracking of coal has an abundant of pore structure and it has good catalytic activity. On this basis, making the modified catalyst when the pyrolysis char is activation and loads Fe by impregnation method. The cracking mechanism of lignite pyrolytic tar is explored by applying gas chromatograph to analyze splitting products of tar. The experimental results showed that: (1) The effect of tar cracking as the pyrolysis temperature, the heating rate, the volatilization of pyrolysis char and particle size increasing is better and better. The effect of the catalytic and cracking of lignite pyrolysis char in tar is best when the heating rate, the pyrolysis temperature, the volatiles of pyrolysis char, particle size is in specific conditions.(2) The activation of pyrolysis char can improve the catalytic effect of pyrolysis char on the tar cracking. But it reduces the effect of the tar cracking when the pyrolysis char is activation loading Fe. (author)

  14. Influence of Si-doping on heteroepitaxially grown a-plane GaN

    Energy Technology Data Exchange (ETDEWEB)

    Wieneke, Matthias; Bastek, Barbara; Noltemeyer, Martin; Hempel, Thomas; Rohrbeck, Antje; Witte, Hartmut; Veit, Peter; Blaesing, Juergen; Dadgar, Armin; Christen, Juergen; Krost, Alois [Otto-von-Guericke-Universitaet Magdeburg, FNW/IEP, Universitaetsplatz 2, 39106 Magdeburg (Germany)

    2011-07-01

    Si-doped a-plane GaN samples with nominal doping levels up to 10{sup 20} cm{sup -3} were grown on r-plane sapphire by metal organic vapor phase epitaxy. Silane flow rates higher than 59 nmol/min lead to three dimensional grown crystallites as revealed by scanning electron microscopy. High resolution X-ray diffraction, photoluminescence and cathodoluminescence suggest considerably reduced defect densities in the large micrometer-sized GaN crystallites. Especially, transmission electron microscopy images verify a very low density of basal plane stacking faults less than 10{sup 4} cm{sup -1} in these crystallites consisting of heteroepitaxially grown a-plane GaN. In our presentation the influence of the Si doping on the basal plane stacking faults will be discussed.

  15. Extremely fine structured cathode for solid oxide fuel cells using Sr-doped LaMnO3 and Y2O3-stabilized ZrO2 nano-composite powder synthesized by spray pyrolysis

    Science.gov (United States)

    Shimada, Hiroyuki; Yamaguchi, Toshiaki; Sumi, Hirofumi; Nomura, Katsuhiro; Yamaguchi, Yuki; Fujishiro, Yoshinobu

    2017-02-01

    A solid oxide fuel cell (SOFC) for high power density operation was developed with a microstructure-controlled cathode using a nano-composite powder of Sr-doped LaMnO3 (LSM) and Y2O3-stabilized ZrO2 (YSZ) synthesized by spray pyrolysis. The individual LSM-YSZ nano-composite particles, formed by crystalline and amorphous nano-size LSM and YSZ particles, showed spherical morphology with uniform particle size. The use of this powder for cathode material led to an extremely fine microstructure, in which all the LSM and YSZ grains (approximately 100-200 nm) were highly dispersed and formed their own network structures. This microstructure was due to the two phase electrode structure control using the powder, namely, nano-order level in each particle and micro-order level between particles. An anode-supported SOFC with the LSM-YSZ cathode using humidified H2 as fuel and ambient air as oxidant exhibited high power densities, such as 1.29 W cm-2 under a voltage of 0.75 V and a maximum power density of 2.65 W cm-2 at 800 °C. Also, the SOFC could be stably operated for 250 h with no degradation, even at a high temperature of 800 °C.

  16. Influence of oxygen doping on resistive-switching characteristic of a-Si/c-Si device

    Science.gov (United States)

    Zhang, Jiahua; Chen, Da; Huang, Shihua

    2017-12-01

    The influence of oxygen doping on resistive-switching characteristics of Ag/a-Si/p+-c-Si device was investigated. By oxygen doping in the growth process of amorphous silicon, the device resistive-switching performances, such as the ON/OFF resistance ratios, yield and stability were improved, which may be ascribed to the significant reduction of defect density because of oxygen incorporation. The device I-V characteristics are strongly dependent on the oxygen doping concentration. As the oxygen doping concentration increases, the Si-rich device gradually transforms to an oxygen-rich device, and the device yield, switching characteristics, and stability may be improved for silver/oxygen-doped a-Si/p+-c-Si device. Finally, the device resistive-switching mechanism was analyzed. Project supported by the Zhejiang Provincial Natural Science Foundation of China (No. LY17F040001), the Open Project Program of Surface Physics Laboratory (National Key Laboratory) of Fudan University (No. KF2015_02), the Open Project Program of National Laboratory for Infrared Physics, Chinese Academy of Sciences (No. M201503), the Zhejiang Provincial Science and Technology Key Innovation Team (No. 2011R50012), and the Zhejiang Provincial Key Laboratory (No. 2013E10022).

  17. Laser induced pyrolysis techniques

    International Nuclear Information System (INIS)

    Vanderborgh, N.E.

    1976-01-01

    The application of laser pyrolysis techniques to the problems of chemical analysis is discussed. The processes occurring during laser pyrolysis are first briefly reviewed. The problems encountered in laser pyrolysis gas chromatography are discussed using the analysis of phenanthrene and binary hydrocarbons. The application of this technique to the characterization of naturally occurring carbonaceous material such as oil shales and coal is illustrated

  18. The potential of pyrolysis technology in climate change mitigation – influence of process design and –parameters, simulated in SuperPro Designer Software

    DEFF Research Database (Denmark)

    Thomsen, Tobias; Hauggaard-Nielsen, Henrik; Bruun, Esben

    This report investigates whether or not it would be possible to produce carbon-negative energy from pyrolysis of wheat straw in a series of Danish agricultural scenarios. A combination of process simulation in SuperPro Designer software, correlations derived from literature studies and experimental...... on scenario settings. The final results of the study have been compared to another study with convincing results. Results concluded that the primary force of the pyrolysis technology is the recalcitrant char product and not the pyrolysis oil. Based on this, the study suggests that despite the trend...... in commercial pyrolysis technology that focuses on fast pyrolysis processes with maximized bio-oil production, the twin challenge of climate mitigation and sustainable energy production is most efficiently addressed with a combination of slow pyrolysis and complete biomass conversion through combustion...

  19. Influences of Silver-Doping on the Crystal Structure, Morphology and Photocatalytic Activity of TiO2 Nanofibers

    DEFF Research Database (Denmark)

    Barakat, Nasser A. M.; Kanjwal, Muzafar Ahmed; Al-Deyab, Salem S.

    2011-01-01

    Doping of titanium dioxide nanofibers by silver nanoparticles revealed distinct improvement in the photocatalytic activ-ity; however other influences have not been investigated. In this work, effect of sliver-doping on the crystal structure, the nanofibrous morphology as well as the photocatalyti...

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

    International Nuclear Information System (INIS)

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

    2012-01-01

    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 21 cm −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 0.98 B 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 −4 Ω cm electrical resistivity, 46 cm 2 /V s Hall mobility and 9.21 × 10 21 cm −3 charge carrier concentration. The X-ray photoelectron spectroscopy study has confirmed 0.15 eV binding energy change for Zn 2p 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. Influence of doping fluorine on the structural, surface morphological and optical properties of CdO films

    Energy Technology Data Exchange (ETDEWEB)

    Aydogu, S.; Cabuk, G. [Dumlupinar University, Department of Physics, Faculty of Science and Art, Kutahya (Turkey); Coban, M.B. [Balikesir University, Department of Physics, Faculty of Science and Art, Balikesir (Turkey)

    2017-06-15

    CdO and CdO:F films were prepared by ultrasonic spray pyrolysis method on glass substrates at temperature of 250 ± 5 C. The structural and optical properties of pure and fluorine doped CdO films were characterized by XRD measurements and UV-VIS spectra, respectively. X-ray diffraction patterns show that the films have the polycrystalline structure with preferred orientation along (111) plane. Scherrer Method and Williamson Hall Method were used for calculating of the crystalline grains and strains of films. It is observed that the films at 8% F doped has better crystallinity level, and F doping decreases the defects in CdO films and improves crystallite quality. By UV-VIS spectra, it is revealed that the film with 8% F doped has a high transmittance about 65% in the visible region together with a direct band gap of 2.70 eV. Thicknesses, refractive indices and extinction coefficient values are determined by spectroscopic ellipsometry technique using Cauchy-Urbach model. (orig.)

  2. Characteristics of liquid product from the pyrolysis of waste plastic mixture at low and high temperatures: influence of lapse time of reaction.

    Science.gov (United States)

    Lee, Kyong-Hwan; Shin, Dae-Hyun

    2007-01-01

    concluded that the characteristics of liquid product on the pyrolysis of plastic mixtures were strongly influenced by lapse time of reaction and degradation temperature.

  3. Characteristics of liquid product from the pyrolysis of waste plastic mixture at low and high temperatures: Influence of lapse time of reaction

    International Nuclear Information System (INIS)

    Lee, Kyong-Hwan; Shin, Dae-Hyun

    2007-01-01

    characteristics of liquid product on the pyrolysis of plastic mixtures were strongly influenced by lapse time of reaction and degradation temperature

  4. Photoelectrochemical Characterization of Sprayed alpha-Fe2O3 Thin Films : Influence of Si Doping and SnO2 Interfacial Layer

    NARCIS (Netherlands)

    Liang, Y.; Enache, C.S.; Van De Krol, R.

    2008-01-01

    a-Fe2O3 thin film photoanodes for solar water splitting were prepared by spray pyrolysis of Fe(AcAc)3. The donor density in the Fe2O3 films could be tuned between 10171020cm-3 by doping with silicon. By depositing a 5 nm SnO2 interfacial layer between the Fe2O3 films and the transparent conducting

  5. Combined influence of fluorine doping and vacuum annealing on the electrical properties of ZnO:Ta films

    Energy Technology Data Exchange (ETDEWEB)

    Subha, K. [Materials Science Research Laboratory, PG and Research Department of Physics, AVVM Sri Pushpam College (Autonomous), Poondi, Thanjavur, 613 503, Tamil Nadu (India); Research Department of Physics, Kunthavai Naachiyaar Govt. Arts College for Women (Autonomous), Thanjavur, 613 007, Tamil Nadu (India); Ravichandran, K., E-mail: kkr1365@yahoo.com [Materials Science Research Laboratory, PG and Research Department of Physics, AVVM Sri Pushpam College (Autonomous), Poondi, Thanjavur, 613 503, Tamil Nadu (India); Sriram, S. [School of Electrical and Electronics Engineering, SASTRA University, Thanjavur, 613 401, Tamil Nadu (India)

    2017-07-01

    Highlights: • First report on combined effect of F doping and annealing on resistivity of ZnO:Ta films. • Various possible incorporation mechanisms of tantalum and fluorine are addressed. • Theoretical validation of Ta and F incorporation by DFT analysis is done. • Quality factor comparable with those obtained by physical methods is achieved.. - Abstract: In this study, our main focus is to investigate the effects of F doping and post deposition annealing (air and vacuum) on the optical and electrical characteristics of tantalum doped zinc oxide films (ZnO:Ta). A cost-effective, automated jet nebulizer spray pyrolysis technique is adopted to deposit the ZnO:Ta:F films. The doping level of Ta is kept constant (1 at.%) and that of F is varied from 5 to 20 at.% in steps of 5 at.%. The electrical resistivity of the as-deposited films decreases for 10 at.% of F concentration. The resistance increases thereafter. The same trend is also observed in annealed films. The reasons for these variations are addressed based on the effective F incorporation into the ZnO lattice and annealing atmosphere with the help of XRD, FESEM, AFM and PL studies. The incorporation of the dopants was confirmed from XPS and EDX analyses and the DFT studies show that the incorporation of the dopants does not affect the stability of the ZnO lattice. Vacuum-annealed films show better electrical properties over the as-deposited and air-annealed counterparts, though their transparency is affected marginally. A minimum resistivity of 0.81 × 10{sup −3} Ω cm and an enhanced quality factor of 2.265 × 10{sup −4} (Ω/sq){sup −1} are achieved for the vacuum-annealed films having Ta + F doping levels as 1 + 10 at.%. These results make this sample a desirable candidate for transparent electrode applications.

  6. Influence of calcium and lithium on the densification and electrical conductivity of gadolinia-doped ceria

    International Nuclear Information System (INIS)

    Porfirio, Tatiane Cristina

    2011-01-01

    In this work, the use of calcium and lithium as sintering aid to gadolinia-doped ceria was systematically investigated. The main purpose was to verify the influence of these additives on the densification and electrical conductivity of sintered ceramics. Powder compositions containing up to 1.5 mol% (metal basis) of calcium or lithium were prepared by both solid state reaction and oxalate coprecipitation methods. The main characterization techniques were thermal analyses, X-ray diffraction, scanning electron microscopy and electrical conductivity by impedance spectroscopy. Both additives promoted densification of gadolinia-doped ceria. The densification increases with increasing the additive content. Different effects on microstructure and electrical conductivity result from the method of preparation, e.g., solid state reaction or coprecipitation. Calcium addition greatly enhances the grain growth compared to lithium addition. The electrical conductivity of specimens containing a second additive is lower than that of pure gadolinia-doped ceria. Both additives influence the intergranular conductivity and favor the exudation of gadolinium out of the solid solution. (author)

  7. Influence of Gaussian white noise on the frequency-dependent linear polarizability of doped quantum dot

    International Nuclear Information System (INIS)

    Ganguly, Jayanta; Ghosh, Manas

    2014-01-01

    Highlights: • Linear polarizability of quantum dot has been studied. • Quantum dot is doped with a repulsive impurity. • The polarizabilities are frequency-dependent. • Influence of Gaussian white noise has been monitored. • Noise exploited is of additive and multiplicative nature. - Abstract: We investigate the profiles of diagonal components of frequency-dependent linear (α xx and α yy ) optical response of repulsive impurity doped quantum dots. The dopant impurity potential chosen assumes Gaussian form. The study principally puts emphasis on investigating the role of noise on the polarizability components. In view of this we have exploited Gaussian white noise containing additive and multiplicative characteristics (in Stratonovich sense). The frequency-dependent polarizabilities are studied by exposing the doped dot to a periodically oscillating external electric field of given intensity. The oscillation frequency, confinement potentials, dopant location, and above all, the noise characteristics tune the linear polarizability components in a subtle manner. Whereas the additive noise fails to have any impact on the polarizabilities, the multiplicative noise influences them delicately and gives rise to additional interesting features

  8. Influence of pyrolysis temperature on lead immobilization by chemically modified coconut fiber-derived biochars in aqueous environments.

    Science.gov (United States)

    Wu, Weidong; Li, Jianhong; Niazi, Nabeel Khan; Müller, Karin; Chu, Yingchao; Zhang, Lingling; Yuan, Guodong; Lu, Kouping; Song, Zhaoliang; Wang, Hailong

    2016-11-01

    Biochar has received widespread attention as an eco-friendly and efficient material for immobilization of toxic heavy metals in aqueous environments. In the present study, three types of coconut fiber-derived biochars were obtained by pyrolyzing at three temperatures, i.e., 300, 500, and 700 °C. In addition, nine types of biochars were prepared by chemical modification with ammonia, hydrogen peroxide, and nitric acid, respectively, which were used to investigate changes in physico-chemical properties by inter alia, Fourier transformation infrared spectrophotometry (FTIR), scanning electron microscope (SEM), and BET specific surface area analysis. Batch sorption experiments were carried out to determine the sorption capacity of the biochars for lead (Pb) in aqueous solutions. Results showed that the cation exchange capacity of biochar pyrolyzed at 300 °C and modified with nitric acid increased threefold compared to the control. Loosely corrugated carbon surface and uneven carbon surface of the biochar pyrolyzed at 300 °C were produced during ammonia and nitric acid modifications. Removal rate of Pb by the coconut biochar pyrolyzed at 300 °C and modified with ammonia was increased from 71.8 to 99.6 % compared to the untreated biochar in aqueous solutions containing 100 mg L -1 Pb. However, chemical modification did not enhance adsorption of Pb of the biochars pyrolyzed at higher temperatures (e.g., 500 or 700 °C), indicating that resistance of biochars to chemical treatment increased with pyrolysis temperature.

  9. Influence of precursor concentration on physical properties of CdO thin films prepared by spray pyrolysis technique using nebulizer

    Energy Technology Data Exchange (ETDEWEB)

    Anitha, M.; Amalraj, L.; Anitha, N. [Virudhunagar Hindu Nadar' s Senthikumara Nadar College (Autonomous), Department of Physics, Virudhunagar, Tamilnadu (India)

    2017-12-15

    Cadmium oxide (CdO) thin films were prepared with different concentrations of precursor solution (0.05, 0.1, 0.15, 0.2 and 0.25 M, respectively) at the optimized temperature (200 C) using the nebulized spray pyrolysis technique to obtain better crystallinity in polycrystalline thin films on amorphous glass substrates. The XRD characterization of those samples revealed a preferential orientation along the (111) plane having a cubic structure. The scanning electron microscopy (SEM) analysis displayed that all the as-deposited thin films have spherical shaped grains. The transmittance of the as-deposited CdO thin films had decreased from 88 to 71% for longer wavelength regions (600-900 nm) as the precursor concentration had increased and then increased for higher precursor concentration. The optical band gap was found to lie between 2.45 and 2.40 eV belonging to direct transition for those thin films. The presence of Cd-O bond (540 cm{sup -1}) was confirmed by FTIR spectrum. The emission properties of CdO thin films were studied by luminescence spectrum recorded at room temperature. A maximum carrier concentration and minimum resistivity values of 4.743 x 10{sup 19} cm{sup -3} and 1.06 x 10{sup -3} Ω-cm, respectively, were obtained for 0.2 M precursor concentration. These CdO thin films have high optical transmittance and high room temperature conductivity, which can be used as the TCO and Solar cell (window layer) material. (orig.)

  10. Morphological transition of ZnO nanostructures influenced by magnesium doping

    International Nuclear Information System (INIS)

    Premkumar, T.; Zhou, Y.S.; Gao, Y.; Baskar, K.; Jiang, L.; Lu, Y.F.

    2012-01-01

    Wurtzite zinc oxide (ZnO) nanochains have been synthesized through high-pressure pulsed laser deposition. The chain-like ZnO nanostructures were obtained from magnesium (Mg) doped ZnO targets, whereas vertically aligned nanorods were obtained from primitive ZnO targets. The Mg doping has influenced the morphological transition of ZnO nanostructures from nanorods to nanochains. The field emission scanning electron microscope images revealed the growth of beaded ZnO nanochains. The ZnO nanochains of different diameters 40 and 120 nm were obtained. The corresponding micro-Raman spectra showed strong E 2H mode of ZnO, which confirmed the good crystallinity of the nanochains. In addition to near band edge emission at 3.28 eV, ZnO nanochains show broad deep level emission at 2.42 eV than that of ZnO nanorods.

  11. Influence of pretreatment temperature cycling on the radiating defect formation in silicon doped by samarium

    International Nuclear Information System (INIS)

    Abdurakhmanov, K.P.; Nazyrov, D.E.

    2006-01-01

    Full text: The raise of thermal and radiation stability as it is known, is one of actual problems of physics semiconductors. Recently it is established, that the rare-earth elements (REE) raise a stability of silicon to exterior action. In this connection the investigation of silicon doped REE by samarium and influence on its properties of heat treatments and radiation exposure is important. In sectional operation the outcomes of investigations of influence of samarium on thermal (600 degree C are reduced; 600 deg. + 900 deg. C; 900 deg. C; 900 deg. C + 600 deg. C; 1100 deg. C; 600 deg. C + 900 deg. C + 1100 deg. C; 900 deg. C + 600 deg. C + 1100 deg. C) thermal defect formation and radiation defect formation (exposure of γ-quanta 60 Co) both in beforehand wrought, and in thermally unfinished samples. After each cycle of heat treatments samples cool fast (throwing off in oil) or slowly (together with the furnace). Doping n-silicon REE by gadolinium and samarium was carried out during cultivation. The concentration of gadolinium and samarium in silicon, on sectional of a neutron-activation analysis was equaled 10 14 - 10 18 cm -3 . As control is model monocrystal silicon such as KEP-15/50. Para-meters of deep levels originating in control and doped REE samples, both past heat treatment or temperature cycling, and irradiated by the γ-quanta are defined by methods of a capacity spectroscopy: DLTS and IRC. The obtained outcomes have shown, that in irradiated with the γ-quanta 60 Co deep levels samples are formed with energies: E C -0,17 eV, E C -0,32 eV, EC-0,41 eV. Thus the parameters of deep levels vary depending on requirements of prestress heat treatment. For example heat treatment at 600 deg. C essentially increments a velocity of introduction of and centre (deep level of E C -0,17 eV), in comparison with a velocity of introduction of this level in samples with prestress heat treatment at 900 deg. C. In samples n-Si doped by samarium effectiveness of formation

  12. Reprint of: Pyrolysis technologies for municipal solid waste: A review

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Dezhen, E-mail: chendezhen@tongji.edu.cn [Thermal & Environmental Engineering Institute, Tongji University, Shanghai 200092 (China); Yin, Lijie; Wang, Huan [Thermal & Environmental Engineering Institute, Tongji University, Shanghai 200092 (China); He, Pinjing [State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China)

    2015-03-15

    Highlights: • MSW pyrolysis reactors, products and environmental impacts are reviewed. • MSW pyrolysis still has to deal with flue gas emissions and products’ contamination. • Definition of standardized products is suggested to formalize MSW pyrolysis technology. • Syngas is recommended to be the target product for single MSW pyrolysis technology. - Abstract: Pyrolysis has been examined as an attractive alternative to incineration for municipal solid waste (MSW) disposal that allows energy and resource recovery; however, it has seldom been applied independently with the output of pyrolysis products as end products. This review addresses the state-of-the-art of MSW pyrolysis in regards to its technologies and reactors, products and environmental impacts. In this review, first, the influence of important operating parameters such as final temperature, heating rate (HR) and residence time in the reaction zone on the pyrolysis behaviours and products is reviewed; then the pyrolysis technologies and reactors adopted in literatures and scale-up plants are evaluated. Third, the yields and main properties of the pyrolytic products from individual MSW components, refuse-derived fuel (RDF) made from MSW, and MSW are summarised. In the fourth section, in addition to emissions from pyrolysis processes, such as HCl, SO{sub 2} and NH{sub 3}, contaminants in the products, including PCDD/F and heavy metals, are also reviewed, and available measures for improving the environmental impacts of pyrolysis are surveyed. It can be concluded that the single pyrolysis process is an effective waste-to-energy convertor but is not a guaranteed clean solution for MSW disposal. Based on this information, the prospects of applying pyrolysis technologies to dealing with MSW are evaluated and suggested.

  13. Pyrolysis technologies for municipal solid waste: A review

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Dezhen, E-mail: chendezhen@tongji.edu.cn [Thermal and Environmental Engineering Institute, Tongji University, Shanghai 200092 (China); Yin, Lijie; Wang, Huan [Thermal and Environmental Engineering Institute, Tongji University, Shanghai 200092 (China); He, Pinjing [State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China)

    2014-12-15

    Highlights: • MSW pyrolysis reactors, products and environmental impacts are reviewed. • MSW pyrolysis still has to deal with flue gas emissions and products’ contamination. • Definition of standardized products is suggested to formalize MSW pyrolysis technology. • Syngas is recommended to be the target product for single MSW pyrolysis technology. - Abstract: Pyrolysis has been examined as an attractive alternative to incineration for municipal solid waste (MSW) disposal that allows energy and resource recovery; however, it has seldom been applied independently with the output of pyrolysis products as end products. This review addresses the state-of-the-art of MSW pyrolysis in regards to its technologies and reactors, products and environmental impacts. In this review, first, the influence of important operating parameters such as final temperature, heating rate (HR) and residence time in the reaction zone on the pyrolysis behaviours and products is reviewed; then the pyrolysis technologies and reactors adopted in literatures and scale-up plants are evaluated. Third, the yields and main properties of the pyrolytic products from individual MSW components, refuse-derived fuel (RDF) made from MSW, and MSW are summarised. In the fourth section, in addition to emissions from pyrolysis processes, such as HCl, SO{sub 2} and NH{sub 3}, contaminants in the products, including PCDD/F and heavy metals, are also reviewed, and available measures for improving the environmental impacts of pyrolysis are surveyed. It can be concluded that the single pyrolysis process is an effective waste-to-energy convertor but is not a guaranteed clean solution for MSW disposal. Based on this information, the prospects of applying pyrolysis technologies to dealing with MSW are evaluated and suggested.

  14. Pyrolysis Recovery of Waste Shipping Oil Using Microwave Heating

    Directory of Open Access Journals (Sweden)

    Wan Adibah Wan Mahari

    2016-09-01

    Full Text Available This study investigated the use of microwave pyrolysis as a recovery method for waste shipping oil. The influence of different process temperatures on the yield and composition of the pyrolysis products was investigated. The use of microwave heating provided a fast heating rate (40 °C/min to heat the waste oil at 600 °C. The waste oil was pyrolyzed and decomposed to form products dominated by pyrolysis oil (up to 66 wt. % and smaller amounts of pyrolysis gases (24 wt. % and char residue (10 wt. %. The pyrolysis oil contained light C9–C30 hydrocarbons and was detected to have a calorific value of 47–48 MJ/kg which is close to those traditional liquid fuels derived from fossil fuel. The results show that microwave pyrolysis of waste shipping oil generated an oil product that could be used as a potential fuel.

  15. Doping influence by some transition elements on the irradiation effects in nuclear waste glasses

    International Nuclear Information System (INIS)

    Florent, Olivier

    2006-06-01

    High-level waste glasses are submitted to auto-irradiation. Modelling it using external irradiations on simple glasses revealed defects production and non negligible structural changes. This thesis aims at determining the impact of a more complex composition on these effects, especially the influence of adding polyvalent transition metals. Silicate, soda-lime and alumino-borosilicate glasses are doped with different iron, chromium and manganese concentrations then β irradiated at different doses up to 10 9 Gy. Non doped glasses show an increase of their density and polymerisation coupled with a molecular oxygen and point defects production. Adding 0.16 mol% Fe decreases the amount of defects by 85 % and all irradiation effects. A Fe 3+ reduction is also observed by EPR, optical absorption and indirectly by Raman spectroscopy. A higher than 0.32 mol% Fe concentration causes complete blockage of the evolution of polymerisation, density and defect production. The same results are obtained on chromium or manganese doped glasses. An original in situ optical absorption device shows the quick decrease of Fe 3+ amount to a 25 % lower level during irradiation. Stopping irradiation causes a lower decrease of 65 %, suggesting a dynamic (h 0 /e-) consuming equilibrium. He + and Kr 3+ ions and γ irradiated glasses tend to confirm these phenomena for all kind of irradiation with electronic excitations. (author)

  16. Influence of solution deposition rate on properties of V{sub 2}O{sub 5} thin films deposited by spray pyrolysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Abd–Alghafour, N. M., E-mail: na2013bil@gmail.com [Iraqi Ministry of Education, Anbar (Iraq); Ahmed, Naser M.; Hassan, Zai; Mohammad, Sabah M. [Nano-Optoelectronics Research and Technology Laboratory, School of Physics, University Sains Malaysia,11800 Penang (Malaysia)

    2016-07-19

    Vanadium oxide (V{sub 2}O{sub 5}) 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 VCl{sub 3} 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 V{sub 2}O{sub 5} 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).

  17. Influence of lithium doping on the structural and electrical characteristics of ZnO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Johny, T. Anto [Centre for Materials for Electronics Technology (C-MET), (Department of Information Technology, Scientific Society, Ministry of Communication and Information Technology, Govt. of India), Athani - PO, Thrissur, 680 581 Kerala (India); Kumar, Viswanathan, E-mail: vkumar10@yahoo.com [Centre for Materials for Electronics Technology (C-MET), (Department of Information Technology, Scientific Society, Ministry of Communication and Information Technology, Govt. of India), Athani - PO, Thrissur, 680 581 Kerala (India); Imai, Hideyuki; Kanno, Isaku [Micro Engineering, Kyoto University, Kyoto 606-8501 (Japan)

    2012-06-30

    Thin films of undoped and lithium-doped Zinc oxide, (Zn{sub 1-x}Li{sub x})O; x = 0, 0.05, 0.10 and 0.20 were prepared by sol-gel method using spin-coating technique on silicon substrates [(111)Pt/Ti/SiO{sub 2}/Si)]. The influence of lithium doping on the structural, electrical and microstructural characteristics have been investigated by means of X-ray diffraction, leakage current, piezoelectric measurements and scanning electron microscopy. The resistivity of the ZnO film is found to increase markedly with low levels (x {<=} 0.05) of lithium doping thereby enhancing their piezoelectric applications. The transverse piezoelectric coefficient, e{sub 31}{sup Low-Asterisk} has been determined for the thin films having the composition (Zn{sub 0.95}Li{sub 0.05})O, to study their suitability for piezoelectric applications. - Highlights: Black-Right-Pointing-Pointer Preferentially c-axis oriented (Zn{sub 1-x}Li{sub x})O films were spin-coated on glass. Black-Right-Pointing-Pointer (Zn{sub 1-x}Li{sub x})O thin films exhibit dense columnar microstructure. Black-Right-Pointing-Pointer Low levels of lithium doping, increases the electrical resistivity of ZnO thin films. Black-Right-Pointing-Pointer (Zn{sub 1-x}Li{sub x})O thin films show high values of transverse piezoelectric coefficient, e{sup Low-Asterisk }{sub 31}.

  18. Influence of Ag doping concentration on structural and optical properties of CdS thin film

    International Nuclear Information System (INIS)

    Kumar, Pragati; Saxena, Nupur; Gupta, Vinay; Agarwal, Avinash

    2015-01-01

    This work shows the influence of Ag concentration on structural properties of pulsed laser deposited nanocrystalline CdS thin film. X-ray photoelectron spectroscopy (XPS) studies confirm the dopant concentration in CdS films and atomic concentration of elements. XPS studies show that the samples are slightly sulfur deficient. GAXRD scan reveals the structural phase transformation from cubic to hexagonal phase of CdS without appearance of any phase of CdO, Ag 2 O or Ag 2 S suggesting the substitutional doping of Ag ions. Photoluminescence studies illustrate that emission intensity increases with increase in dopant concentration upto 5% and then decreases for higher dopant concentration

  19. Influence of Impurities on the Luminescence of Er3+ Doped BaTiO3 Nanophosphors

    Directory of Open Access Journals (Sweden)

    G. D. Webler

    2014-01-01

    Full Text Available The influence of the presence of barium carbonate (BaCO3 phase on the luminescence properties of barium titanate nanocrystals (BaTiO3 powders was investigated. Structural and optical characterizations of erbium (Er3+ doped BaTiO3 synthesized by the sol-emulsion-gel were performed. Using Fourier transform infrared spectroscopy and X-ray powder diffraction, we identified the presence of impurities related to BaCO3 and quantified its fraction. It was observed that the presence of BaCO3 phase, even at low levels, depletes significantly the infrared-to-visible upconverted luminescence efficiency of the produced nanopowders.

  20. Electrolyte influence on the Cu nanoparticles electrodeposition onto boron doped diamond electrode

    International Nuclear Information System (INIS)

    Matsushima, Jorge Tadao; Santos, Laura Camila Diniz; Couto, Andrea Boldarini; Baldan, Mauricio Ribeiro; Ferreira, Neidenei Gomes

    2012-01-01

    This paper presents the electrolyte influence on deposition and dissolution processes of Cu nanoparticles on boron doped diamond electrodes (DDB). Morphological, structural and electrochemical analysis showed BDD films with good reproducibility, quality and reversible in a specific redox system. Electrodeposition of Cu nanoparticles on DDB electrodes in three different solutions was influenced by pH and ionic strength of the electrolytic medium. Analyzing the process as function of the scan rate, it was verified a better efficiency in 0,5 mol L -1 Na 2 SO 4 solution. Under the influence of the pH and ionic strength, Cu nanoparticles on DDB may be obtained with different morphologies and it was important for defining the desired properties. (author)

  1. The potential of pyrolysis technology in climate change mitigation - influence of process design and - parameters, simulated in SuperPro Designer software

    Energy Technology Data Exchange (ETDEWEB)

    Thomsen, T.; Hauggaard-Nielsen, H.; Bruun, E.W.; Ahrenfeldt, J.

    2011-01-15

    This report investigates whether or not it would be possible to produce carbon-negative energy from pyrolysis of wheat straw in a series of Danish agricultural scenarios. A combination of process simulation in SuperPro Designer software, correlations derived from literature studies and experimental work, and overall balance calculations has been applied in the process. The study deviates from other studies of pyrolysis and biochar production by the inclusion of substitution energy impact on the overall carbon-balance. Substitution energy is integrated to account for the gap between the energy production from the pyrolysis and the full energy potential of the biomass, quantified by complete conversion in either combustion or gasification systems. It was concluded that it is feasible to produce carbon-negative energy under a variation of different settings, but also that the negative carbon-balance is only robust for the slow pyrolysis scenario. The CO{sub 2} benefit of the most carbon-negative slow pyrolysis process is estimated to be around 10 % of the atmospheric carbon stored in the original biomass when natural gas is applied for energy substitution. This process avoids the emission of around 150-200 kg CO{sub 2}/ton wheat straw with substitution energy with a Denmark 2007 average carbon-intensity. This result is weighted against the net emissions of the carbon-'neutral' process of conventional combustion. This emission is in this report estimated to be around 50 - 150 kg CO{sub 2}/ton straw depending on scenario settings. The final results of the study have been compared to another study with convincing results. Results concluded that the primary force of the pyrolysis technology is the recalcitrant char product and not the pyrolysis oil. Based on this, the study suggests that despite the trend in commercial pyrolysis technology that focuses on fast pyrolysis processes with maximized bio-oil production, the twin challenge of climate mitigation and

  2. Influence of coal rank and pyrolysis/hydropyrolysis temperature on nitrogen oxide emission during coal char combustion

    Energy Technology Data Exchange (ETDEWEB)

    Stanczyk, K.; Miga, K. [Polish Academy of Sciences, Gliwice (Poland). Institute of Coal Chemistry

    1999-07-01

    The formation of NO during the combustion of chars was investigated. The formation of NO was correlated with carbon oxides emission. The way in which the reactivity of chars influences NO emission was investigated. 6 refs., 2 figs., 2 tabs.

  3. Modeling of biomass pyrolysis

    International Nuclear Information System (INIS)

    Samo, S.R.; Memon, A.S.; Akhund, M.A.

    1995-01-01

    The fuels used in industry and power sector for the last two decades have become expensive. As a result renewable energy source have been emerging increasingly important, of these, biomass appears to be the most applicable in the near future. The pyrolysis of biomass plays a key role amongst the three major and important process generally encountered in a gas producer, namely, pyrolysis, combustion and reduction of combustion products. Each biomass has its own pyrolysis characteristics and this important parameters must be known for the proper design and efficient operation of a gasification system. Thermogravimetric analysis has been widely used to study the devolatilization of solid fuels, such as biomass. It provides the weight loss history of a sample heated at a predetermined rate as a function of time and temperature. This paper presents the experimental results of modelling the weight loss curves of the main biomass components i.e. cellulose, hemicellulose and lignin. Thermogravimetric analysis of main components of biomass showed that pyrolysis is first order reaction. Furthermore pyrolysis of cellulose and hemicelluloe can be regarded as taking place in two stages, for while lignin pyrolysis is a single stage process. This paper also describes the Thermogravimetric Analysis (TGA) technique to predict the weight retained during pyrolysis at any temperature, for number of biomass species, such as cotton stalk, bagasse ad graoundnut shell. (author)

  4. Catalytic biomass pyrolysis process

    Science.gov (United States)

    Dayton, David C.; Gupta, Raghubir P.; Turk, Brian S.; Kataria, Atish; Shen, Jian-Ping

    2018-04-17

    Described herein are processes for converting a biomass starting material (such as lignocellulosic materials) into a low oxygen containing, stable liquid intermediate that can be refined to make liquid hydrocarbon fuels. More specifically, the process can be a catalytic biomass pyrolysis process wherein an oxygen removing catalyst is employed in the reactor while the biomass is subjected to pyrolysis conditions. The stream exiting the pyrolysis reactor comprises bio-oil having a low oxygen content, and such stream may be subjected to further steps, such as separation and/or condensation to isolate the bio-oil.

  5. Influence of pyrolysis conditions on the CO2/CH4 and O2/N2 perm selectivity of supported carbon molecular sieve membranes

    International Nuclear Information System (INIS)

    Mohd Fikri Abdul Rahman; Wan Mohd Hafiz Faizal Wan Harun; Mohd Azmier Ahmad

    2010-01-01

    This work focused on the effect of pyrolysis conditions onto supported carbon molecular sieve membranes performance in pure gas permeation and perm selectivity. The membrane support was synthesis by carbonization of titania mixed with cellulose acetate at temperature of 125 degree Celsius. The molecular sieving membrane layer was obtained by coating the polyvinyl alcohol-glutaraldehyde solution onto the membrane support before heated at various pyrolysis temperatures and holding times. The optimum preparation conditions were found at pyrolysis temperature and holding time of 400 degree Celsius and 30 minutes, respectively. At this point, the CO 2 and O 2 permeation flux were 2.63 ml/ min and 2.67 ml/ min, respectively. Meanwhile, the perm selectivities of CO 2 / CH 4 and O 2 / N 2 were 1.87 and 1.92, respectively. (author)

  6. Influence Al doped ZnO nanostructure on structural and optical properties

    International Nuclear Information System (INIS)

    Ramelan, Ari Handono; Wahyuningsih, Sayekti; Chasanah, Uswatul; Munawaroh, Hanik

    2016-01-01

    The preparation of Al-doped ZnO (AZO) thin films prepared by the spin-coating method was reported. Preparation of AZO was conducted by annealing treatment at a temperature of 700°C. While the spin-coating process of AZO thin films were done at 2000 and 3000 rpm respectively. The structural properties of ZnO were determined by X- ray diffraction (XRD) analysis. ZnOnanostructure was formed after annealed at atemperature of 400°C.The morphology of ZnO was determined by Scanning Electron Microscopy (SEM) showed the irregular morphology about 30-50µm in size. Al doped on ZnO influenced the optical properties of those material. Increasing Al contain on ZnO cause of shifting to the lower wavelength. The optical properties of the ZnO as well as AZO films showed that higher reflectance on the ultraviolet region so those materials were used as anti-reflecting agent.Al addition significantly enhance the optical transparency and induce the blue-shift in optical bandgap of ZnO films.

  7. Influence of film thickness on structural, optical, and electrical properties of spray deposited antimony doped SnO{sub 2} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Abhijit A., E-mail: aay_physics@yahoo.co.in

    2015-09-30

    Transparent conducting antimony doped SnO{sub 2} thin films with varying thickness were deposited by chemical spray pyrolysis technique from non-aqueous solvent Propan-2-ol. The effect of film thickness on the properties of antimony doped SnO{sub 2} thin films have been studied. X-ray diffraction measurements showed tetragonal crystal structure of as-deposited antimony doped SnO{sub 2} films irrespective of film thickness. The surface morphology of antimony doped SnO{sub 2} thin film is spherical with the continuous distribution of grains. Electrical and optical properties were investigated by Hall Effect and optical measurements. The average optical transmittance of films decreased from 89% to 73% within the visible range (350–850 nm) with increase in film thickness. The minimum value of sheet resistance observed is 4.81 Ω/cm{sup 2}. The lowest resistivity found is 3.76 × 10{sup −4} Ω cm at 660 nm film thickness. - Highlights: • Effect of film thickness on the properties of antimony doped SnO{sub 2} thin films • Crystalline size in the range of 34–37 nm • Average transmittance decreased from 89% to 73% in the visible region. • Minimum sheet resistance of 4.81 Ω/cm{sup 2} • Lowest resistivity is found to be 3.76 × 10{sup −4} Ω cm at 660 nm film thickness.

  8. Pyrolysis of waste tyres: a review.

    Science.gov (United States)

    Williams, Paul T

    2013-08-01

    Approximately 1.5 billion tyres are produced each year which will eventually enter the waste stream representing a major potential waste and environmental problem. However, there is growing interest in pyrolysis as a technology to treat tyres to produce valuable oil, char and gas products. The most common reactors used are fixed-bed (batch), screw kiln, rotary kiln, vacuum and fluidised-bed. The key influence on the product yield, and gas and oil composition, is the type of reactor used which in turn determines the temperature and heating rate. Tyre pyrolysis oil is chemically very complex containing aliphatic, aromatic, hetero-atom and polar fractions. The fuel characteristics of the tyre oil shows that it is similar to a gas oil or light fuel oil and has been successfully combusted in test furnaces and engines. The main gases produced from the pyrolysis of waste tyres are H(2), C(1)-C(4) hydrocarbons, CO(2), CO and H(2)S. Upgrading tyre pyrolysis products to high value products has concentrated on char upgrading to higher quality carbon black and to activated carbon. The use of catalysts to upgrade the oil to a aromatic-rich chemical feedstock or the production of hydrogen from waste tyres has also been reported. Examples of commercial and semi-commercial scale tyre pyrolysis systems show that small scale batch reactors and continuous rotary kiln reactors have been developed to commercial scale. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. A numerical investigation of the influence of radiation and moisture content on pyrolysis and ignition of a leaf-like fuel element

    Science.gov (United States)

    B.L. Yashwanth; B. Shotorban; S. Mahalingam; C.W. Lautenberger; David Weise

    2016-01-01

    The effects of thermal radiation and moisture content on the pyrolysis and gas phase ignition of a solid fuel element containing high moisture content were investigated using the coupled Gpyro3D/FDS models. The solid fuel has dimensions of a typical Arctostaphylos glandulosa leaf which is modeled as thin cellulose subjected to radiative heating on...

  10. The influence of predeformations and annealings on yield stress and modulus of elongation essentially yttrium doped copper

    International Nuclear Information System (INIS)

    Neklyudov, I.M.; Sytin, V.I.; Voevodin, V.N.

    2003-01-01

    The researches results of influence of predeformations and annealings on elastic and plastic characteristics of vacuum melting and yttrium doped copper are given. The interrelation between elastic and plastic characteristics has been shown. It is shown that the yield stress and modulus of elongation essentially depend on predeformations and annealings and they are the structurally sensitive characteristics

  11. Investigation of Influence of Surface Nanoparticle on Emission Properties of Scandia-Doped Dispenser Cathodes

    Science.gov (United States)

    Zhang, Xizhu; Wang, Jinshu; Wang, Yiman; Liu, Wei; Zhou, Meiling; Gao, Zhiyuan

    2013-06-01

    The microstructure of a fully activated scandia doped dispenser (SDD) cathode has been studied by scanning electron microscope (SEM). The observation results display that nanoparticles appear at the growth steps and the surface of tungsten grains of the fully activated SDD cathode. To study the influence of the nanoparticles on the emission, the local electric field strengths around the nanoparticles have been calculated by Maxwell 2D code and Comsol. The calculation results show that the local electric field strengths are enhanced by 1.1 to 3.8 times to average value based on different model conditions. The highest field strength is about 1.54 × 105 V/cm at an average field strength of 40 KV/cm, which is related to a space-charge limited (SCL) current density of 100 A/cm2 in the experimental configuration. This implies the field strength is not high enough to cause field emission.

  12. Influence of Ag doping concentration on structural and optical properties of CdS thin film

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Pragati, E-mail: pkumar.phy@gmail.com [Department of Physics, Bareilly College, Bareilly, 243 005, Uttar Pradesh (India); Department of Physics and Astrophysics, University of Delhi, Delhi, 110 007 (India); Saxena, Nupur; Gupta, Vinay [Department of Physics and Astrophysics, University of Delhi, Delhi, 110 007 (India); Agarwal, Avinash [Department of Physics, Bareilly College, Bareilly, 243 005, Uttar Pradesh (India)

    2015-05-15

    This work shows the influence of Ag concentration on structural properties of pulsed laser deposited nanocrystalline CdS thin film. X-ray photoelectron spectroscopy (XPS) studies confirm the dopant concentration in CdS films and atomic concentration of elements. XPS studies show that the samples are slightly sulfur deficient. GAXRD scan reveals the structural phase transformation from cubic to hexagonal phase of CdS without appearance of any phase of CdO, Ag{sub 2}O or Ag{sub 2}S suggesting the substitutional doping of Ag ions. Photoluminescence studies illustrate that emission intensity increases with increase in dopant concentration upto 5% and then decreases for higher dopant concentration.

  13. Influence of rare earth (Nd{sup +3}) doping on structural and magnetic properties of nanocrystalline manganese-zinc ferrite

    Energy Technology Data Exchange (ETDEWEB)

    Naik, Pranav P., E-mail: drppn1987@gmail.com [Department of Physics, Goa University, Taleigao Plateau, Goa, 403206 (India); Tangsali, R.B. [Department of Physics, Goa University, Taleigao Plateau, Goa, 403206 (India); Meena, S.S.; Yusuf, S.M. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai, 400085 (India)

    2017-04-15

    Ultrafine nanopowders of Mn{sub 0.6}Zn{sub 0.4}Fe{sub 2-x}Nd{sub x}O{sub 4} (x = 0, 0.04, 0.06, 0.08, and 0.1) were prepared using combustion method. The influence of Nd{sup +3} doping on structural parameters, morphological characteristics and magnetic properties were investigated. Formation of pure spinel phase was confirmed using X-ray powder diffraction (XRPD). Nd{sup +3} doping in Mn-Zn ferrite samples have shown remarkable influence on all the properties that were under investigation. An increase in lattice constant commensurate with increasing Nd{sup +3} concentrations was observed in the samples. The crystallite size calculated from XRPD data and grain size observed from Transmission Electron Microscope showed a proportionate decrement with increment in rare earth doping. An increase in mass density, X-ray density, particle strain and decrease in porosity were the other effects noticed on the samples as a result of Nd{sup +3} doping. The corresponding tetrahedral, octahedral bond lengths and bond angles estimated from XRPD data have also shown substantial influence of the Nd{sup +3} doping. Magnetic parameters namely saturation magnetization (M{sub S}) and net magnetic moment η{sub B}, estimated using vibrating sample magnetometer (VSM) were found to depend on the Nd{sup +3} doping. Mössbauer spectroscopy was employed to study the magnetic environment of Mössbauer active ions and detection of superparamagnetic behavior in nanocrystalline rare earth ferrite material. The isomer shift values obtained from Mössbauer spectra indicate the presence of Fe{sup +3} ions at tetrahedral site (A-site) and octahedral site (B-site), respectively. - Highlights: • Synthesis of Nd doped Mn-Zn ferrite nanoparticles using combustion method. • Successful doping of Nd{sup +3} at octahedral site in ferrite structure. • Existence of Fe{sup +3} oxidation state at both A-Site and B-site. • Enhanced saturation magnetization due to altered cation distribution by Nd doping

  14. Influence of ZrO2 particles on fluorine-doped lead dioxide electrodeposition process from nitrate bath

    International Nuclear Information System (INIS)

    Yao, Yingwu; Zhou, Tao; Zhao, Chunmei; Jing, Qiming; Wang, Yang

    2013-01-01

    The influence of ZrO 2 particles on fluorine-doped lead dioxide electrodeposition process on the glass carbon electrode (GCE) from lead nitrate electrolytes was studied by cyclic voltammetry (CV) and chronoamperometry (CA), coupled with the scanning electron microscope (SEM). Instantaneous nucleation mechanism is found for fluorine-doped lead dioxide electrodeposition in the presence of ZrO 2 particles according to Scharifker–Hills’ model with three-dimensional growth. The results show that the addition of ZrO 2 particles decrease the active surface area of the GCE, and the growth of the lead dioxide crystallites was obstructed

  15. Influence of organic solvent treatment on elasticoluminescent property of europium-doped strontium aluminates

    International Nuclear Information System (INIS)

    Fujio, Yuki; Xu, Chao-Nan; Terasaki, Nao; Ueno, Naohiro

    2014-01-01

    The influence of an organic solvent treatment on elasticoluminescent (ELS) characteristics of mechanoluminescent (ML) sensor using the composite film consisting of an ELS material and epoxy resin was investigated. We used strontium aluminate doped with a small amount of europium (SrAl 2 O 4 :Eu, SAOE) as an ELS material in this study. After evaluating the ELS characteristics of the fabricated ML sensors using SAOE treated with/without various organic solvents, SAOE treated with methanol and ethanol showed lower ELS intensities than that of untreated SAOE. In contrast, the ELS response curves against strain for the ML sensors using SAOE treated with acetone and toluene, overlapped with that of untreated SAOE. From the characterization of SAOE treated with alcohols, such as methanol and ethanol, we can hypothesize that poor ELS characteristics is due to the degradation of the SAOE grain surfaces by the hydrolyze reaction of SAOE with hydroxyl group of alcohol. Thus, on the basis of the obtained results, we can conclude that the selection of organic solvent used in the preparation of SAOE film is of considerable importance in the development of ML sensor with a highly-reliable ELS characteristic. -- Highlights: • Influence of organic solution treatment on the sensing characteristics of a mechanoluminescent (ML) sensor using SrAl 2 O 4 :Eu has been investigated. • An alcohol treatment of SAOE powder has considerable effect on its ML characteristic. • There is almost no influence of acetone and toluene treatments on ML characteristics

  16. Demographic factors influencing the GH system: Implications for the detection of GH doping in sport.

    Science.gov (United States)

    Nelson, Anne E; Ho, Ken K Y

    2009-08-01

    Application of methods for detecting GH doping depend on being able to discriminate between abnormal levels due to doping and normal physiological levels of circulating proteins that change in response to exogenous administration. Constituents of the IGF and collagen systems have been shown to be promising markers of GH abuse. Their ultimate utility, however, depends on identification of the factors that regulate their concentrations in blood. Among these are demographic factors that are known to influence these markers in the general population. In a large cross-sectional study of the GH-responsive markers in over 1000 elite athletes from 12 countries representing 4 major ethnic groups and 10 sport types, we have shown that there is a significant negative correlation between age and all the IGF and collagen markers we studied, with a rapid decrease in early adolescence. Age was the major contribution to the variability, equivalent to >80% of the attributable variation in IGF-I and the collagen markers. The IGF axis markers were all significantly higher in women, and the collagen markers significantly higher in men, however, the contribution of gender was smaller than that of age, except for IGFBP-3 and ALS. BMI had a minor contribution to variability of the GH-responsive markers. After adjustment for the confounding influences of age, gender and BMI, the effect of ethnicity in elite athletes was trivial except for IGFBP-3 and ALS, which were both lower in Africans and higher in Caucasians. Compared to age and gender, the contribution of sport type was also modest. Our findings on the influence of age, gender, BMI and sport type have also been confirmed in a study of mostly Caucasian elite athletes in the post-competition setting. In conclusion, age and gender are the major determinants of variability for IGF-I and the collagen markers, whereas ethnicity and sport type have a minor influence. Therefore, a test based on IGF-I and the collagen markers must take age

  17. Refining fast pyrolysis of biomass

    NARCIS (Netherlands)

    Westerhof, Roel Johannes Maria

    2011-01-01

    Pyrolysis oil produced from biomass is a promising renewable alternative to crude oil. Such pyrolysis oil has transportation, storage, and processing benefits, none of which are offered by the bulky, inhomogeneous solid biomass from which it originates. However, pyrolysis oil has both a different

  18. Influence of Tb doping on the luminescence characteristics of ZnO nanoparticles

    International Nuclear Information System (INIS)

    Sharma, A.; Dhar, S.; Singh, B. P.; Kundu, T.; Spasova, M.; Farle, M.

    2012-01-01

    Structural and optical properties of the Tb-doped ZnO nanoparticles with average diameter ≈4 nm have been systematically investigated. Our X-ray diffraction studies show a contraction of the ZnO lattice with the increase of the Tb mole-fraction x for x ≤ 0.02 and an expansion beyond x ≈ 0.02. The photoluminescence spectra are found to be comprised of a near band edge ultra violet luminescence (UVL) and a broad green luminescence (GL) band. Under the atmospheric condition, the intensity of the GL band is found to increase with the Tb mole-fraction over the entire doping range. On the other hand, under the vacuum condition, it has been observed that the GL intensity decreases with the increase of x up to x ≈ 0.02 but further increase of x leads to a gradual revival of the GL emission. Our study suggests that for x ≤ 0.02, GL results due to the physisorption of certain groups on the surface of the nanoparticles (GL-groups). It is also found that in this Tb mole-fraction regime, Tb incorporates mostly on the surface of the nanoparticles and affects the UVL to GL intensity ratio by influencing the attachment of the GL-groups. However, for x > 0.02, GL originates not only from the GL-groups but also from certain point defects, which are likely to be generated due to the incorporation of Tb in the core of the nanoparticles. A simple rate equation model is introduced to get a quantitative understanding about the variation of the density of the centers responsible for the GL emission as a function of x under the atmospheric and the vacuum conditions.

  19. Cellular dislocations patterns in monolike silicon: Influence of stress, time under stress and impurity doping

    Science.gov (United States)

    Oliveira, V. A.; Rocha, M.; Lantreibecq, A.; Tsoutsouva, M. G.; Tran-Thi, T. N.; Baruchel, J.; Camel, D.

    2018-05-01

    Besides the well-known local sub-grain boundaries (SGBs) defects, monolike Si ingots grown by Directional Solidification present distributed background cellular dislocation structures. In the present work, the influence of stress level, time under stress, and doping by O and Ge, on the formation of dislocation cells in monolike silicon, is analysed. This is achieved by performing a comparative study of the dislocation structures respectively obtained during crystallisation of pilot scale monolike ingots on Czochralski (CZ) and monolike seeds, during annealing of Float Zone (FZ), CZ, and 1 × 1020 at/cm3 Ge-doped CZ (GCZ) samples, and during 4-point bending of FZ and GCZ samples at 1300 °C under resolved stresses of 0.3, 0.7 and 1.9 MPa during 1-20 h. Synchrotron X-ray White-beam Topography and Rocking Curve Imaging (RCI) are applied to visualize the dislocation arrangements and to quantify the spatial distribution of the associated lattice distortions. Annealed samples and samples bent under 0.3 MPa present dislocation structures corresponding to transient creep stages where dislocations generated from surface defects are propagating and multiplying in the bulk. The addition of the hardening element Ge is found to block the propagation of dislocations from these surface sources during the annealing test, and to retard dislocation multiplication during bending under 0.3 MPa. On the opposite, cellular structures corresponding to the final stationary creep stage are obtained both in the non-molten seeds and grown part of monolike ingots and in samples bent under 0.7 and 1.9 MPa. A comparative discussion is made of the dynamics of formation of these final dislocation structures during deformation at high temperature and monolike growth.

  20. Influence of Cr doping on the stability and structure of small cobalt oxide clusters

    Energy Technology Data Exchange (ETDEWEB)

    Tung, Nguyen Thanh; Lievens, Peter; Janssens, Ewald, E-mail: ewald.janssens@fys.kuleuven.be [Laboratory of Solid-State Physics and Magnetism, KU Leuven, B-3001 Leuven (Belgium); Tam, Nguyen Minh; Nguyen, Minh Tho [Department of Chemistry, KU Leuven, B-3001 Leuven (Belgium)

    2014-07-28

    The stability of mass-selected pure cobalt oxide and chromium doped cobalt oxide cluster cations, Co{sub n}O{sub m}{sup +} and Co{sub n−1}CrO{sub m}{sup +} (n = 2, 3; m = 2–6 and n = 4; m = 3–8), has been investigated using photodissociation mass spectrometry. Oxygen-rich Co{sub n}O{sub m}{sup +} clusters (m ⩾ n + 1 for n = 2, 4 and m ⩾ n + 2 for n = 3) prefer to photodissociate via the loss of an oxygen molecule, whereas oxygen poorer clusters favor the evaporation of oxygen atoms. Substituting a single Co atom by a single Cr atom alters the dissociation behavior. All investigated Co{sub n−1}CrO{sub m}{sup +} clusters, except CoCrO{sub 2}{sup +} and CoCrO{sub 3}{sup +}, prefer to decay by eliminating a neutral oxygen molecule. Co{sub 2}O{sub 2}{sup +}, Co{sub 4}O{sub 3}{sup +}, Co{sub 4}O{sub 4}{sup +}, and CoCrO{sub 2}{sup +} are found to be relatively difficult to dissociate and appear as fragmentation product of several larger clusters, suggesting that they are particularly stable. The geometric structures of pure and Cr doped cobalt oxide species are studied using density functional theory calculations. Dissociation energies for different evaporation channels are calculated and compared with the experimental observations. The influence of the dopant atom on the structure and the stability of the clusters is discussed.

  1. Correlation Between Pyrolysis Atmosphere and Carbon Molecular Sieve Membrane Performance Properties

    KAUST Repository

    Kiyono, Mayumi; Koros, William J.; Williams, Paul J.

    2011-01-01

    Carbon molecular sieve (CMS) membranes have attractive separation performance properties, greatly exceeding an "upper bound" trade-off curve of polymeric membrane performance. CMS membranes are prepared by pyrolyzing polymers, well above their glass transition temperatures. Multiple factors, such as polymer precursor and pyrolysis protocol, are known to affect the separation performance. In this study, a correlation observed between pyrolysis atmosphere and CMS separation performance properties is discussed. Specifically, oxygen exposure during the pyrolysis process is the focus. The theory and details of the oxygen exposure and development of a new CMS preparation method using oxygen as a "dopant" will be described with a strong correlation observed with separation performance for CMS membranes prepared with various polymer precursors. In addition, study of possible mass transfer limitations on the oxygen "doping" process will be described to clarify the basis for the equilibrium-based interpretation of doping data. The method is also explored by changing the pyrolysis temperature. © 2011 Elsevier B.V.

  2. Influence of Pyrolysis Temperature and Type of Ligno-Cellulose and Cellulose Biomass on Yield, Specific Surface Area and Mechanical Resistance of Active Coal

    OpenAIRE

    Pohořelý, Michael

    2012-01-01

    In the Czech Republic, there are many contaminated agricultural soils due to anthropogenic activity and geogenic origin. The contaminated biomass of plants grown on the contaminated soils needs to be appropriately disposed of to prevent the re-releace of heavy metals into the environment. One way of processing contaminated biomass is pyrolysis, where the heavy metals are concentrated in biochar (active coal). This can be applied to soil where it improves the physical properties. The aim of ...

  3. The influence of carrier density and doping type on lithium insertion and extraction processes at silicon surfaces

    International Nuclear Information System (INIS)

    McSweeney, W.; Lotty, O.; Glynn, C.; Geaney, H.; Holmes, J.D.; O’Dwyer, C.

    2014-01-01

    The Li + insertion and extraction characteristics at n-type and p-type Si(100) electrodes with different carrier density and doping type are investigated by cyclic voltammetry and constant current measurements. The insertion and extraction potentials are demonstrated to vary with cycling and the occurrence of an activation effect is shown in n-type electrodes where the charge capacity and voltammetric currents are found to be much higher than p-type electrodes. A rate-dependent redox process influenced by the surface region electronic density, which influences the magnitude of cyclic voltammetry current is found at Si(100) surface regions during Li insertion and extraction. At p-type Si(100) surface regions, a thin, uniform film forms at lower currents, while also showing a consistently high (>70%) Coulombic efficiency for Li extraction. The p-type Si(100) surface region does not undergo crack formation after deintercalation and the amorphization was demonstrated using transmission electron microscopy (TEM). X-ray photoelectron spectroscopy (XPS) and Raman scattering demonstrate that highly doped n-type Si(100) retains Li as a silicide and converts to an amorphous phase as a two-step phase conversion process. The findings show the succinct dependence of Li insertion and extraction processes for uniformly doped Si(100) single crystals and how the doping type and its effect on the semiconductor-solution interface dominate Li insertion and extraction, composition, crystallinity changes and charge capacity

  4. Influence of the radiation type on properties of silicon doped by erbium

    International Nuclear Information System (INIS)

    Nazyrov, D.E.

    2006-01-01

    Full text: It is known that on effectiveness of formation and kinetics of annealing of radiation damages presence causing, uncontrollable electrical of fissile or inactive impurities, the concentration and position in a lattice of the semiconductor strongly influence. From this point of view, the impurities of group of rare earths elements (REE) represent major interest, since interacting with primary radiation imperfections they create electrical passive complexes such as 'impurity + defect', thus raising radiation stability of silicon. The purpose of sectional operation was the investigations of influence such as radiation exposures: in γ-quanta 60 Co and high-velocity electrons with an energy 3,5 MeV on properties of silicon doped REE-erbium. The doping of silicon REE was carried out during cultivation. The concentration REE in silicon, on sectional of a neutron-activation analysis was equaled 10 14 10 18 cm -3 . As control is model the monocrystalline silicon such as KEP-15 50 was investigation. The experimental outcomes are obtained through methods DLTS, IRC, and also at examination of a Hall effect and conductance is model, measuring of concentration optically active of centers of oxygen and carbon. In samples irradiated in the γ-quanta 60 Co in an interval of doses 10 16 -5·10 18 cm -2 and high-velocity electrons from 5·10 13 up to 10 18 el.·cm -2 the formation various DL in a forbidden region is revealed, which parameters are well-known A- and, E-centres etc. Depending on a radiation dose in an energy distribution of radiation imperfections in Si of essential concentration modifications is not observed. The comparison doses of associations detected DL in irradiated n-Si with similar associations in control samples shows, that a velocity of introduction of radiation imperfections (A- and E-centres) and imperfection with a deep level Ec-0,32 eV) in samples containing REE much lower, than in control samples. The lifetime of non-equilibrium charge carriers

  5. Catalytic pyrolysis of hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Vail' eva, N A; Buyanov, R A

    1979-01-01

    Catalytic pyrolysis of petroleum fractions (undecane) was performed with the object of clarifying such questions as the mechanism of action of the catalyst, the concepts of activity and selectivity of the catalyst, the role of transport processes, the temperature ranges and limitations of the catalytic process, the effect of the catalyst on secondary processes, and others. Catalysts such as quartz, MgO, Al/sub 2/O/sub 3/, were used. Analysis of the experimental findings and the fact that the distribution of products is independent of the nature of the surface, demonstrate that the pyrolysis of hydrocarbons in the presence of catalysts is based on the heterogeneous-homogeneous radical-chain mechanism of action, and that the role of the catalysts reduces to increasing the concentration of free radicals. The concept of selectivity cannot be applied to catalysts here, since they do not affect the mechanism of the unfolding of the process of pyrolysis and their role consists solely in initiating the process. In catalytic pyrolysis the concepts of kinetic and diffusive domains of unfolding of the catalytic reaction do not apply, and only the outer surface of the catalyst is engaged, whereas the inner surface merely promotes deletorious secondary processes reducing the selectivity of the process and the activity of the catalyst. 6 references, 2 figures.

  6. Pyrolysis of Pine Wood

    DEFF Research Database (Denmark)

    Fjellerup, Jan Søren; Ahrenfeldt, Jesper; Henriksen, Ulrik Birk

    2005-01-01

    In this study, pinewood has been pyrolyzed using a fixed heating rate with a variable end-temperature. The pyrolysis process has been simulated using a mechanism with three parallel reactions for the formation of char, gas and tar. First order irreversible kinetics is assumed. This kind of model ...

  7. Influence of neodymium-doping on structure and properties of yttrium aluminium garnet

    DEFF Research Database (Denmark)

    Zhang, X.D.; He, W.; Yue, Yuanzheng

    2013-01-01

    We study the impact of the Nd-doping on the grain formation, the crystal structure, and the fluorescence of the Yttrium Aluminum Garnet (YAG). The results show that Nd-doping leads to the YAG lattice expansion and distortion, and hence to an increase in defect concentration. This is attributed to...

  8. Biomass pyrolysis for chemicals

    Energy Technology Data Exchange (ETDEWEB)

    De Wild, P.

    2011-07-15

    The problems associated with the use of fossil fuels demand a transition to renewable sources (sun, wind, water, geothermal, biomass) for materials and energy where biomass provides the only renewable source for chemicals. In a biorefinery, biomass is converted via different technologies into heat, power and various products. Here, pyrolysis (thermal degradation without added oxygen) of lignocellulosic biomass can play an important role, because it leads to an array of useful chemicals. Examples are furfural and acetic acid from hemicellulose, levoglucosan from cellulose and phenols and biochar from lignin. Since the three major biomass polymers hemicellulose, cellulose and lignin possess dissimilar thermal stabilities and reactivities, type and amount of degradation products are tunable by proper selection of the pyrolysis conditions. To determine if step-wise pyrolysis would be suitable for the production of chemicals, staged degasification of lignocellulosic biomass was studied. Due to limited yields, a hot pressurized water pre-treatment (aquathermolysis) followed by pyrolysis was subsequently developed as an improved version of a staged approach to produce furfural and levoglucosan from the carbohydrate fraction of the biomass. Lignin is the only renewable source for aromatic chemicals. Lignocellulosic biorefineries for bio-ethanol produce lignin as major by-product. The pyrolysis of side-streams into valuable chemicals is of prime importance for a profitable biorefinery. To determine the added-value of lignin side-streams other than their use as fuel for power, application research including techno-economic analysis is required. In this thesis, the pyrolytic valorisation of lignin into phenols and biochar was investigated and proven possible.

  9. CHARACTERISTICS OF CORN STALK HEMICELLULOSE PYROLYSIS IN A TUBULAR REACTOR

    OpenAIRE

    Gao-Jin Lv; Shu-Bin Wu; Rui Lou

    2010-01-01

    Pyrolysis characteristics of corn stalk hemicellulose were investigated in a tubular reactor at different temperatures, with focus mainly on the releasing profiles and forming behaviors of pyrolysis products (gas, char, and tar). The products obtained were further identified using various approaches (including GC, SEM, and GC-MS) to understand the influence of temperature on product properties and compositions. It was found that the devolatilization of hemicellulose mainly occurred at low tem...

  10. Calcination temperature influenced multiferroic properties of Ca-doped BiFeO3 nanoparticles

    International Nuclear Information System (INIS)

    Dhir, Gitanjali; Uniyal, Poonam; Verma, N. K.

    2015-01-01

    The influence of Ca-doping and particle size on structural, morphological and magnetic properties of BiFeO 3 nanoparticles has been studied. A sol-gel method was employed for the synthesis of nanoparticles and their particle size was tailored by varying the calcination temperature. Structural analysis revealed a rhombohedral distortion induced by Ca-substitution. The broadening of diffraction peaks with decreasing calcination temperature was indicative of reduction in crystallite size. The morphological analysis revealed the formation of agglomerated nanoparticles having average particle size ranging from 10-15 and 50-55 nm for C4 and C6, respectively. The agglomeration is attributed to high surface energy of nanoparticles. Ferromagnetism has been displayed by all the synthesized nanoparticles. Enhancement of saturation magnetization with Ca-substitution is attributed to suppression of spin cycloid structure by the reduction in size, lattice distortion and creation of oxygen vacancies by the substitution of divalent ion at trivalent site. Further, this value increases as a function of decreasing particle size. Strong particle size effects on magnetic properties of the synthesized nanoparticles are owed to increasing surface to volume ratio. All these observations are indicative of strong dependence of multiferroism on particle size

  11. Influence of sputtering gas pressure on properties of transparent conducting Si-doped zinc oxide films

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Hua; Liu, Hunfa; Lei, Chengxin [Shandong Univ. of Technology, Zibo (China). Dept. of Sciences

    2013-10-15

    Si-doped zinc oxide (SZO, Si 3%) thin films were deposited on glass substrates by means of direct current magnetron sputtering under different pressures. The influence of sputtering pressure on structure, morphology, optical and electrical properties of SZO thin films was investigated. The results reveal that the sputtering pressures have a significant impact on the growth rate, crystal quality and electrical properties of the films, but have little impact on the optical properties of the films. SZO thin film samples grown on glasses are polycrystalline with a hexagonal wurtzite structure and have a preferred orientation along the c-axis perpendicular to the substrate. When the sputtering pressure increases from 2 to 8 Pa, the film surface becomes compact and smooth, the degree of crystallization of the films increases, and the resistivity of films decreases. However, when the sputtering pressure continues to increase from 8 to 10 Pa, the degree of crystallization of the films decreases, the grain size decreases, and the resistivity of the films increases. SZO(3%) thin film deposited at a sputtering pressure of 8 Pa shows the largest carrier concentration, the largest mobility, the lowest resistivity of 3.0 x 10{sup -4} {Omega} cm and a high overall transmission of 93.3% in the visible range. (orig.)

  12. Influence of fabrication parameter on the nanostructure and photoluminescence of highly doped p-porous silicon

    Energy Technology Data Exchange (ETDEWEB)

    Li, Shaoyuan [National Engineering Laboratory for Vacuum Metallurgy, Kunming University of Science and Technology, Kunming 650093 (China); Faculty of Metallurgical and energy engineering, Kunming University of Science and Technology, Kunming 650093 (China); Ma, Wenhui, E-mail: mwhsilicon@163.com [National Engineering Laboratory for Vacuum Metallurgy, Kunming University of Science and Technology, Kunming 650093 (China); Faculty of Metallurgical and energy engineering, Kunming University of Science and Technology, Kunming 650093 (China); Zhou, Yang, E-mail: zhouyangnano@163.com [National Engineering Laboratory for Vacuum Metallurgy, Kunming University of Science and Technology, Kunming 650093 (China); Faculty of Metallurgical and energy engineering, Kunming University of Science and Technology, Kunming 650093 (China); Chen, Xiuhua [Faculty of Physical Science and Technology, Yunnan University, Kunming 650091 (China); Ma, Mingyu [National Engineering Laboratory for Vacuum Metallurgy, Kunming University of Science and Technology, Kunming 650093 (China); Faculty of Metallurgical and energy engineering, Kunming University of Science and Technology, Kunming 650093 (China); Xiao, Yongyin [Faculty of Physical Science and Technology, Yunnan University, Kunming 650091 (China); Xu, Yaohui [National Engineering Laboratory for Vacuum Metallurgy, Kunming University of Science and Technology, Kunming 650093 (China); Faculty of Metallurgical and energy engineering, Kunming University of Science and Technology, Kunming 650093 (China)

    2014-02-15

    Porous silicon (PS) was prepared by anodizing highly doped p-type silicon in the solution of H{sub 2}O/ethanol/HF. The effects of key fabrication parameters (HF concentration, etching time and current density) on the nanostructure of PS were carefully investigated by AFM, SEM and TEM characterization. According to the experimental results, a more full-fledged model was developed to explain the crack behaviors on PS surface. The photoluminescence (PL) of resulting PS was studied by a fluorescence spectrophotometer and the results show that PL peak positions shift to shorter wavelength with the increasing current density, anodisation time and dilution of electrolyte. The PL spectra blue shift of the sample with higher porosity is confirmed by HRTEM results that the higher porosity results in smaller Si nanocrystals. A linear model (λ{sub PL/nm}=620.3–0.595P, R=0.905) was established to describe the correlation between PL peak positions and porosity of PS. -- Highlights: • The effect of fabrication parameter on the nanostructure of PS is investigated. • The influence of nanostructure on the photoluminescence behaviors is studied • A full-fledged model for expounding the crack behaviors of PS is presented. • The correlation between the porosity and PL peak blue shift is described by a linear model.

  13. Influence of Oxychlorine Phases During the Pyrolysis of Organic Molecules: Implications for the Quest of Organics on Mars with the SAM Experiment Onboard the Curiosity Rover

    Science.gov (United States)

    Millan, M.; Szopa, C.; Buch, A.; Belmahdi, I.; Glavin, D. P.; Freissinet, C.; Eigenbrode, J. L.; Archer, P. D., Jr,; Sutter, B.; Mahaffy, P.

    2017-01-01

    One among the main objectives of the Sample Analysis at Mars (SAM) experiment is the in situ molecular analysis of gases evolving from solid samples heated up to approximately 850 degrees Centigrade, and collected by Curiosity on Mars surface/sub-surface in Gale crater. With this aim, SAM uses a gas-chromatograph coupled to a quadrupole mass spectrometer (GC-QMS) devoted to separate, detect and identify both volatile inorganic and organic compounds. SAM detected chlorinated organic molecules produced in evolved gas analysis (EGA) experiments. Several of these were also detected by the Viking experiments in 1976. SAM also detected oxychlorine compounds that were present at the Phoenix landing site. The oxychlorines may be prevelant over much of the martian surface. The C1 to C3 aliphatic chlorohydrocarbons (chloromethane and di- and trichloromethane) detected by SAM were attributed to reaction products occurring between the oxychlorines phases and the organic compounds coming from SAM instrument background. But SAM also showed the presence of a large excess of chlorobenzene and C2 to C4 dichloroalkanes among the volatile species released by the Cumberland sample of the Sheepbed mudstone. For the first time in the history of the Mars exploration, this proved the presence of Mars indigenous organic material at the Mars' surface. However, the identification of the precursor organic compounds of these chlorohydrocarbons is difficult due to the complexity of the reactions occurring during the sample pyrolysis. Laboratory pyrolysis experiments have demonstrated that oxychlorines phases such as perchlorates and chlorates, decomposed into dioxygen and volatile chlorine bearing molecules (HCl and/or Cl2) during the pyrolysis. These chemical species can then react with the organic molecules present in the martian solid samples through oxidation, chlorination and oxychlorination processes.

  14. Pyrolysis of tyres. Influence of the final temperature of the process on emissions and the calorific value of the products recovered

    International Nuclear Information System (INIS)

    Diez, C.; Martinez, O.; Calvo, L.F.; Cara, J.; Moran, A.

    2004-01-01

    A study was made of the pyrolysis of tyre particles, with the aim of determining the possibilities of using the products resulting from the process as fuel. Three final temperatures were used, determined from thermogravimetric data. The design of the experiment was a horizontal oven containing a reactor into which particles of the original tyre were placed. After the process, a solid fraction (char) remained in the reactor, while the gases generated went through a set of scrubbers where most of the condensable fraction (oils) was retained. Finally, once free of this fraction, the gases were collected in glass ampoules. Solid and liquids fractions were subjected to thermogravimetric analyses in order to study their combustibility. The gas fraction was analysed by means of gas chromatography to establish the content of CO, CO 2 , H 2 and hydrocarbons present in the samples (mainly components of gases produced in the pyrolysis process). A special study was made of the sulphur and chlorine content of all the fractions, as the presence of these elements could be problematic if the products are used as fuel. Tyre pyrolysis engenders a solid carbon residue that concentrates sulphur and chorine, with a relatively high calorific value, although not so high as that of the original tyre. The liquid fraction produced by the process has a high calorific value, which rises with the final temperature, up to 40 MJ/kg. The chlorine content of this fraction is negligible. Over 95% of the gas fraction, regardless of the final temperature, is composed of hydrocarbons of a low molecular weight and hydrogen, this fraction also appearing to be free of chlorine

  15. Influence of pyrolysis temperature and hardwood species on resulting biochar properties and their effect on azimsulfuron sorption as compared to other sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Trigo, Carmen, E-mail: carmentrigo1@gmail.com [Department of Soil, Water & Climate, University of Minnesota, 1991 Upper Buford Circle, St. Paul, MN 55108 (United States); Cox, Lucia, E-mail: lcox@irnase.csic.es [Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNASE-CSIC), P.O. Box 1052, 41080 Seville (Spain); Spokas, Kurt, E-mail: kurt.spokas@ars.usda.gov [USDA-Agricultural Research Service, 1991 Upper Buford Circle, Rm. 439, St. Paul, MN 55108 (United States)

    2016-10-01

    Azimsulfuron is an acidic herbicide with a high water solubility which makes risk of groundwater contamination a concern. Various wood based biochars produced at different pyrolysis temperatures were characterized along with their sorption capacity for the herbicide azimsulfuron. In addition, we compared sorption on biochars with sorption on mineral sorbents such as clay minerals and iron oxides. In biochar formed at high temperatures (500 °C and 700 °C), FT-IR studies confirmed the increase in aromaticity. Scanning electron microscope (SEM) images of the biochars showed differences in the macroporous structure and lower size pores at higher temperatures. SSA (Specific Surface Area) of the biochars increased with pyrolysis temperature and, for all different biochars, this resulted in higher sorption of azimsulfuron. In the case of mineral sorbents, sorption is not related to SSA. Higher sorption is observed in a montmorillonite, of lower SSA, than in mixture of clay minerals with 30% smectite (w/w). On the contrary as with the clays, sorption on the two iron oxyhydroxides increased with SSA. Desorption studies showed hysteresis. Leaching studies showed no effect on azimsulfuron retention on soil column amended with apple wood biochar, while a reduction of azimsulfuron in leachates in soil columns amended with the modified montmorillonite and alder wood biochar (500 °C). Total retention was shown for alder wood biochar. - Highlights: • Use of biochars and mineral sorbents to mitigate azimsulfuron water contamination • Sorption relates with SSA for biochar and iron oxyhydroxide but not for clays. • Higher sorption values for biochar pyrolysis at 700 °C than mineral sorbents • Different effects on leaching for apple wood biochar, SW-Fe and alder wood biochar.

  16. Influence of pyrolysis temperature and hardwood species on resulting biochar properties and their effect on azimsulfuron sorption as compared to other sorbents

    International Nuclear Information System (INIS)

    Trigo, Carmen; Cox, Lucia; Spokas, Kurt

    2016-01-01

    Azimsulfuron is an acidic herbicide with a high water solubility which makes risk of groundwater contamination a concern. Various wood based biochars produced at different pyrolysis temperatures were characterized along with their sorption capacity for the herbicide azimsulfuron. In addition, we compared sorption on biochars with sorption on mineral sorbents such as clay minerals and iron oxides. In biochar formed at high temperatures (500 °C and 700 °C), FT-IR studies confirmed the increase in aromaticity. Scanning electron microscope (SEM) images of the biochars showed differences in the macroporous structure and lower size pores at higher temperatures. SSA (Specific Surface Area) of the biochars increased with pyrolysis temperature and, for all different biochars, this resulted in higher sorption of azimsulfuron. In the case of mineral sorbents, sorption is not related to SSA. Higher sorption is observed in a montmorillonite, of lower SSA, than in mixture of clay minerals with 30% smectite (w/w). On the contrary as with the clays, sorption on the two iron oxyhydroxides increased with SSA. Desorption studies showed hysteresis. Leaching studies showed no effect on azimsulfuron retention on soil column amended with apple wood biochar, while a reduction of azimsulfuron in leachates in soil columns amended with the modified montmorillonite and alder wood biochar (500 °C). Total retention was shown for alder wood biochar. - Highlights: • Use of biochars and mineral sorbents to mitigate azimsulfuron water contamination • Sorption relates with SSA for biochar and iron oxyhydroxide but not for clays. • Higher sorption values for biochar pyrolysis at 700 °C than mineral sorbents • Different effects on leaching for apple wood biochar, SW-Fe and alder wood biochar

  17. Influence of dopant on dielectric properties of polyaniline weakly doped with dichloro and trichloroacetic acids

    International Nuclear Information System (INIS)

    Fattoum, A; Arous, M; Gmati, F; Dhaoui, W; Mohamed, A Belhadj

    2007-01-01

    We report the results of dielectric measurements over the frequency range10 Hz-1 MHz and the temperature range 150-300 K on polyaniline subjected to doping with dichloroacetic acid (DCA) and trichloroacetic acid (TCA) with various doping levels (6.1%, 8.2%, 13.3% and 4.1%, 6.15%, 13.5%, respectively). Conductivity is increased when the doping level or temperature is increased and samples doped with TCA are more conductive than those doped with DCA. A high frequency relaxation peak is observed in the loss factor curves attributed to the motion of charge carriers in the bulk polymer. A second loss peak appears in the low frequency range when we use the dielectric modulus representation and is attributed to electrode polarization. Both relaxations are well fitted by the Havriliak-Negami function, and the fitting parameters are determined. The characteristic relaxation frequency is described by the Arrhenius law. The activation energy for both relaxations is decreased by increasing the doping level and it is lower in the case of TCA doping acid

  18. Pyrolysis and Gasification

    DEFF Research Database (Denmark)

    Astrup, Thomas; Bilitewski, B.

    2011-01-01

    a waste management perspective, pyrolysis and gasification are of relatively little importance as an overall management option. Today, gasification is primarily used on specific waste fractions as opposed to mixed household wastes. The main commercial activity so far has been in Japan, with only limited....... Today gasification is used within a range of applications, the most important of which are conversion of coal into syngas for use as chemical feedstock or energy production; but also gasification of biomass and waste is gaining significant interest as emerging technologies for sustainable energy. From...... success in Europe and North America (Klein et al., 2004). However, pyrolysis and gasification of waste are generally expected to become more widely used in the future. A main reason for this is that public perceptions of waste incineration in some countries is a major obstacle for installing new...

  19. Photoelectrochemical Characterization of Sprayed α-Fe2O3 Thin Films: Influence of Si Doping and SnO2 Interfacial Layer

    Directory of Open Access Journals (Sweden)

    Yongqi Liang

    2008-01-01

    Full Text Available α-Fe2O3 thin film photoanodes for solar water splitting were prepared by spray pyrolysis of Fe(AcAc3. The donor density in the Fe2O3 films could be tuned between 1017–1020 cm-3 by doping with silicon. By depositing a 5 nm SnO2 interfacial layer between the Fe2O3 films and the transparent conducting substrates, both the reproducibility and the photocurrent can be enhanced. The effects of Si doping and the presence of the SnO2 interfacial layer were systematically studied. The highest photoresponse is obtained for Fe2O3 doped with 0.2% Si, resulting in a photocurrent of 0.37 mA/cm2 at 1.23 VRHE in a 1.0 M KOH solution under 80 mW/cm2 AM1.5 illumination.

  20. Influence of In doping on electro-optical properties of ZnO films

    Indian Academy of Sciences (India)

    Doped-zinc oxide; microstructure; optical parameters; electrical conductivity. 1. Introduction ..... In-interstitial atoms determine the widening of the bandgap caused by .... Melendez-Lira M A and de la Olvera L M 2005 Thin Solid Films. 490 132.

  1. Comparison of the influence of boron and aluminium doping on the material properties of electrochemically deposited ZnO films

    Energy Technology Data Exchange (ETDEWEB)

    Calnan, Sonya [Helmholtz-Zentrum für Materialien und Energie GmbH, Hahn-Meitner Platz 1, 14109 Berlin (Germany); Riedel, Wiebke; Gledhill, Sophie [Helmholtz-Zentrum für Materialien und Energie GmbH, Hahn-Meitner Platz 1, 14109 Berlin (Germany); Fachbereich Physik, Freie Universitaet Berlin, Arnimallee 14, 14195 Berlin (Germany); Stannowski, Bernd [Helmholtz-Zentrum für Materialien und Energie GmbH, Hahn-Meitner Platz 1, 14109 Berlin (Germany); Lux-Steiner, Martha Ch. [Helmholtz-Zentrum für Materialien und Energie GmbH, Hahn-Meitner Platz 1, 14109 Berlin (Germany); Fachbereich Physik, Freie Universitaet Berlin, Arnimallee 14, 14195 Berlin (Germany); Schlatmann, Rutger [Helmholtz-Zentrum für Materialien und Energie GmbH, Hahn-Meitner Platz 1, 14109 Berlin (Germany); Fachbereich 1 Ingenieurwissenschaften I, University of Applied Science (HTW) Berlin, Wilhelminenhofstraße 75 A, 12459 Berlin (Germany)

    2015-11-02

    The effect of varying the boron and aluminium content of the starting electrolyte for extrinsically doped ZnO films grown on SnO{sub 2}:F substrates by electrochemical deposition was investigated. The ZnO:B film surface was characterized by grains with mainly hexagonal faces exposed while the exposed faces of the ZnO:Al grains were rectangular. Whereas a B{sup 3+}/Zn{sup 2+} ratio of up to 10 at.% in the electrolyte had no significant effect on the crystalline structure of the ZnO films, an Al{sup 3+}/Zn{sup 2+} ratio above 0.25 at.% increased the disorder in the crystalline structure. All the boron doped films exhibit a strong E{sub 2}-high Raman mode related to wurtzite ZnO structure but this peak was much weaker for ZnO:Al and diminished with increasing Al incorporation in the films. Exposing the films to ultra-violet light reduced their effective sheet resistance from values beyond measurement range to values between 40 and 5000 kΩ/sq for film thicknesses of 200–550 nm. Inspection of the optical spectra near the bandgap edge and the plasma edge in the mid infrared range, showed that the Al-doping resulted in a higher carrier concentration ~ 10{sup 20} cm{sup −3} than B-doping. X-ray electron spectroscopy showed that the dopant efficiency was limited by the absence of dopant atoms near the surface of all the ZnO:B films and of the lightly doped ZnO:Al and, by the formation of aluminium oxide at the surface of the more highly doped ZnO:Al films. - Highlights: • Crystalline ZnO grown by electrochemical deposition. • Comparison of influence of H{sub 3}BO{sub 3} and Al(NO{sub 3}){sub 3} as dopant sources. • Different ZnO crystalline orientation for Al and boron doping. • Film surface chemical composition suppressed electrical conductivity.

  2. Pyrolysis process and apparatus

    Science.gov (United States)

    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.

  3. Influence of MgSO{sub 4} doping on the properties of zinc tris–thiourea sulphate (ZTS) single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Selvapandiyan, M., E-mail: mselvapandiyan@rediffmail.com [Department of Physics, Sri Vidya Mandir Arts and Science College, Uthangarai 635 207 (India); Arumugam, J. [Department of Physics, Sri Vidya Mandir Arts and Science College, Uthangarai 635 207 (India); Sundaramoorthi, P. [Department of Physics, Thiruvalluvar Government Arts College, Rasipuram 637 401 (India); Sudhakar, S. [CSIR–National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110 012 (India)

    2013-12-15

    Highlights: •The influence of MgSO{sub 4} doping on the properties of ZTS single crystals grown at room temperature. •Thermal stability of the crystals increased with incorporation of Mg atom. •Energy band gap was estimated from UV–vis spectra. •ZTS is a potential material for frequency conversion. •Both pure and doped ZTS crystals are belonging to category of typical insulating materials. -- Abstract: The influence of MgSO{sub 4} doping on the properties of zinc tris–thiourea sulphate single crystals grown at room temperature by slow evaporation solution growth technique was studied. Powder XRD analysis confirmed the orthorhombic crystal structure with noncentrosymmetric space group Pca2{sub 1}. The mechanical properties of the grown crystals were analysed by Vicker’s microhardness method. Functional groups present in the materials were identified by FTIR spectral analysis in the range between 4000 and 400 cm{sup −1}. The UV–Vis spectrum indicates that the UV cut-off wavelength of the crystals has less than 297 nm. The thermal stability of the grown crystals was determined with the aid of thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC). Second order nonlinear optical behaviour of the grown crystals have been confirmed by Kurtz powder second harmonic generation (SHG) test.

  4. High temperature SU-8 pyrolysis for fabrication of carbon electrodes

    DEFF Research Database (Denmark)

    Hassan, Yasmin Mohamed; Caviglia, Claudia; Hemanth, Suhith

    2017-01-01

    In this work, we present the investigation of the pyrolysis parameters at high temperature (1100 °C) for the fabrication of two-dimensional pyrolytic carbon electrodes. The electrodes were fabricated by pyrolysis of lithographically patterned negative epoxy based photoresist SU-8. A central...... composite experimental design was used to identify the influence of dwell time at the highest pyrolysis temperature and heating rate on electrical, electrochemical and structural properties of the pyrolytic carbon: Van der Pauw sheet resistance measurements, cyclic voltammetry, electrochemical impedance...... spectroscopy and Raman spectroscopy were used to characterize the pyrolytic carbon. The results show that the temperature increase from 900 °C to 1100 °C improves the electrical and electrochemical properties. At 1100 °C, longer dwell time leads to lower resistivity, while the variation of the pyrolysis...

  5. Distribution of sulphur into products from waste tire pyrolysis

    International Nuclear Information System (INIS)

    Susa, D.; Haydary, J.; Markos, J.

    2012-01-01

    Tire pyrolysis is getting growing attention as an effective waste tire disposal method in comparison to environmentally less friendly methods like dumping or incineration. But the scrap tire sulphur content can be a potential obstacle to scrap tire utilization as a fuel. In this paper the distribution of sulphur into tire pyrolysis yields, solid (char) and liquid (tar), was investigated. The pyrolysis experiments were carried out under different conditions to determine the partitioning of sulphur into pyrolysis products. The influence of different temperatures and reaction times was investigated in a laboratory flow reactor under nitrogen atmosphere. Solid and liquid residues were collected and analyzed by elemental analysis. The sulphur content in residual char and tar was determined using an elemental analyzer and the sulphur forms in tar were characterized by the X-ray photoelectron spectroscopy (XPS). (Authors)

  6. Sports and health : the influence of motivational orientation on body image and doping behaviors

    OpenAIRE

    Lugo, Ric

    2009-01-01

    Health is much talked about topic in today’s society, likewise with sports. Sports and exercise have been introduced has an entranceway to healthier living styles. But increasing reports about how athletes and exercisers use doping agents that are contrary to health beliefs and recommendations from the World Anti-Doping Agency are found in the media. Body Image and eating disorders has also seen a rise in media reports, especially in the sporting world. Athletes are now models and are visible...

  7. Controlled air pyrolysis incinerator

    International Nuclear Information System (INIS)

    Dufrane, K.H.; Wilke, M.

    1982-01-01

    An advanced controlled air pyrolysis incinerator has been researched, developed and placed into commercial operation for both radioactive and other combustible wastes. Engineering efforts cocentrated on providing an incinerator which emitted a clean, easily treatable off-gas and which produced a minimum amount of secondary waste. Feed material is continuously fed by gravity into the system's pyrolysis chamber without sorting, shredding, or other such pretreatment. Metal objects, liquids such as oil and gasoline, or solid products such as resins, blocks of plastic, tire, animal carcasses, or compacted trash may be included along with normal processed waste. The temperature of the waste is very gradually increased in a reduced oxygen atmosphere. Volatile pyrolysis gases are produced, tar-like substances are cracked and the resulting product, a relatively uniform, easily burnable material, is introduced into the combustion chamber. Steady burning is thus accomplished under easily controlled excess air conditions with the off-gasthen passing through a simple dry clean-up system. Gas temperatures are then reduced by air dilution before passing through final HEPA filters. Both commercial and nuclear installations have been operated with the most recent application being the central incinerator to service West Germany's nuclear reactors

  8. Influence of Al grain boundaries segregations and La-doping on embrittlement of intermetallic NiAl

    Science.gov (United States)

    Kovalev, Anatoly I.; Wainstein, Dmitry L.; Rashkovskiy, Alexander Yu.

    2015-11-01

    The microscopic nature of intergranular fracture of NiAl was experimentally investigated by the set of electron spectroscopy techniques. The paper demonstrates that embrittlement of NiAl intermetallic compound is caused by ordering of atomic structure that leads to formation of structural aluminum segregations at grain boundaries (GB). Such segregations contain high number of brittle covalent interatomic bonds. The alloying by La increases the ductility of material avoiding Al GB enrichment and disordering GB atomic structure. The influence of La alloying on NiAl mechanical properties was investigated. GB chemical composition, atomic and electronic structure transformations after La doping were investigated by AES, XPS and EELFS techniques. To qualify the interatomic bonds metallicity the Fermi level (EF) position and electrons density (neff) in conduction band were determined in both undoped and doped NiAl. Basing on experimental results the physical model of GB brittleness formation was proposed.

  9. Influence of Gaussian white noise on the frequency-dependent first nonlinear polarizability of doped quantum dot

    Energy Technology Data Exchange (ETDEWEB)

    Ganguly, Jayanta [Department of Chemistry, Brahmankhanda Basapara High School, Basapara, Birbhum 731215, West Bengal (India); Ghosh, Manas, E-mail: pcmg77@rediffmail.com [Department of Chemistry, Physical Chemistry Section, Visva Bharati University, Santiniketan, Birbhum 731 235, West Bengal (India)

    2014-05-07

    We investigate the profiles of diagonal components of frequency-dependent first nonlinear (β{sub xxx} and β{sub yyy}) optical response of repulsive impurity doped quantum dots. We have assumed a Gaussian function to represent the dopant impurity potential. This study primarily addresses the role of noise on the polarizability components. We have invoked Gaussian white noise consisting of additive and multiplicative characteristics (in Stratonovich sense). The doped system has been subjected to an oscillating electric field of given intensity, and the frequency-dependent first nonlinear polarizabilities are computed. The noise characteristics are manifested in an interesting way in the nonlinear polarizability components. In case of additive noise, the noise strength remains practically ineffective in influencing the optical responses. The situation completely changes with the replacement of additive noise by its multiplicative analog. The replacement enhances the nonlinear optical response dramatically and also causes their maximization at some typical value of noise strength that depends on oscillation frequency.

  10. Structural, optoelectronic, luminescence and thermal properties of Ga-doped zinc oxide thin films

    International Nuclear Information System (INIS)

    Shinde, S.S.; Shinde, P.S.; Oh, Y.W.; Haranath, D.; Bhosale, C.H.; Rajpure, K.Y.

    2012-01-01

    Highlights: ► The ecofriendly deposition of Ga-doped zinc oxide. ► Influence of Ga doping onto physicochemical properties in aqueous media. ► Electron–phonon coupling by Raman. ► Chemical bonding structure and valence band analysis by XPS. - Abstract: Ga-doped ZnO thin films are synthesized by chemical spray pyrolysis onto corning glass substrates in aqueous media. The influence of gallium doping on to the photoelectrochemical, structural, Raman, XPS, morphological, optical, electrical, photoluminescence and thermal properties have been investigated in order to achieve good quality films. X-ray diffraction study depicts the films are polycrystalline and fit well with hexagonal (wurtzite) crystal structure with strong orientations along the (0 0 2) and (1 0 1) planes. Presence of E 2 high mode in Raman spectra indicates that the gallium doping does not change the wurtzite structure. The coupling strength between electron and LO phonon has experimentally estimated. In order to understand the chemical bonding structure and electronic states of the Ga-doped ZnO thin films XPS analysis have been studied. SEM images shows the films are adherent, compact, densely packed with hexagonal flakes and spherical grains. Optical transmittance and reflectance measurements have been carried out. Room temperature PL spectra depict violet, blue and green emission in deposited films. The specific heat and thermal conductivity study shows the phonon conduction behavior is dominant in these polycrystalline films.

  11. Influence of dose history on thermoluminescence response of Ge-doped silica optical fibre dosimeters

    International Nuclear Information System (INIS)

    Moradi, F.; Mahdiraji, G.A.; Dermosesian, E.; Khandaker, M.U.; Ung, N.M.; Mahamd Adikan, F.R.; Amin, Y.M.

    2017-01-01

    Nowadays, silica based optical fibres show enough potential to be used as TL dosimeters in different applications. Reuse of optical fibre as a practical dosimeter demands to complete removal of accumulated doses via previous irradiations. This work investigates the existence and/or effect of remnant doses in fibre dosimeter from the previous irradiations, and proposes a method to control this artifact. A single mode Ge-doped optical fibre is used as TL radiation sensor, while a well calibrated Gammacell with 60 Co source is used for irradiations. The effect of irradiation history on the TL response of optical fibres is surveyed extensively for doses ranged from 1 to 1000 Gy. The results show that the absorbed dose history in a fibre affects its response in the next irradiation cycles. It is shown that a dose history of around 100 Gy can increase the response of optical fibre by a factor of 1.72. The effect of annealing at higher temperatures on stabilizing the fibre response is also examined and results revealed that another alteration in the structure of trapping states occurs in glass medium which can change the sensitivity of fibres. Preservation of the sensitivity during successive irradiation cycles can be achieved by a proper annealing procedure accompanied by a pre-dose treatment. - Highlights: • Influence of dose history on TL characteristics of fibre dosimeter is explored. • The phenomenon behind the TL variation caused by dose history is discussed. • Effect of annealing temperature on performance of fibre dosimeter is studied. • Pre-treatment methods for mitigating variation in reproducibility are proposed.

  12. Fast Pyrolysis of Four Lignins from Different Isolation Processes Using Py-GC/MS

    Directory of Open Access Journals (Sweden)

    Xiaona Lin

    2015-06-01

    Full Text Available Pyrolysis is a promising approach that is being investigated to convert lignin into higher value products including biofuels and phenolic chemicals. In this study, fast pyrolysis of four types of lignin, including milled Amur linden wood lignin (MWL, enzymatic hydrolysis corn stover lignin (EHL, wheat straw alkali lignin (AL and wheat straw sulfonate lignin (SL, were performed using pyrolysis gas-chromatography/mass spectrometry (Py-GC/MS. Thermogravimetric analysis (TGA showed that the four lignins exhibited widely different thermolysis behaviors. The four lignins had similar functional groups according to the FTIR analysis. Syringyl, guaiacyl and p-hydroxyphenylpropane structural units were broken down during pyrolysis. Fast pyrolysis product distributions from the four lignins depended strongly on the lignin origin and isolation process. Phenols were the most abundant pyrolysis products from MWL, EHL and AL. However, SL produced a large number of furan compounds and sulfur compounds originating from kraft pulping. The effects of pyrolysis temperature and time on the product distributions from corn stover EHL were also studied. At 350 °C, EHL pyrolysis mainly produced acids and alcohols, while phenols became the main products at higher temperature. No obvious influence of pyrolysis time was observed on EHL pyrolysis product distributions.

  13. Obtention of zirconia films stabilized with Yttria via pyrolysis spray: study of the solvent influence; Obtencao de filmes de zirconia estabilizada com itria via spray pirolise: estudo da influencia do solvente

    Energy Technology Data Exchange (ETDEWEB)

    Halmenschlager, Cibele Melo; Vieira, Ramaugusto da Porciuncula; Takimi, Antonio Shigueaki; Bergmann, Carlos Perez; Silva, Aline Lima da; Malfatti, Celia de Fraga [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia de Minas, Metalurgica e de Materiais (PPGEM). Lab. de Materiais Ceramicos (LACER)]. E-mail: cibelemh@yahoo.com.br

    2008-07-01

    Yttria-stabilized-zirconia (YSZ) has been object of many studies, due to its great chemical stability and excellent ionic conduction in high temperature. This material has been studies with an intention of to be used with electrolyte of oxide solid fuel cells, which work in high temperature. The aim of the present work was to evaluate the influence of the solvent on the elaboration of crystalline films of YSZ via spray pyrolysis. The film was prepared by spray pyrolysis with zirconium acetylacetonate (Zr(C{sub 6}H{sub 7}O{sub 2}){sub 4}) and yttrium chloride (YCl{sub 3}.6H{sub 2}O), dissolved in different solvents: ethanol (C{sub 2}H{sub 6}O), ethanol (C{sub 2}H{sub 6}O) + propyleneglycol (C{sub 3}H{sub 8}O{sub 2}) with volume ratio (1:1) and ethanol (C{sub 2}H{sub 6}O) + diethylene glycol butyl ether (C{sub 8}H{sub 18}O{sub 3}) with volume ratio of 1:1. A disk of steel 316L was used as substrate. The amorphous film was deposited in the substrate heated at 280 deg C {+-} 50 deg C. After deposition from thermal treatment at 700 deg C the amorphous film was changed into Yttria-stabilized-zirconia film. The thermal behavior of the films has been studied by both (DTA/TGA) thermogravimetric and mass spectroscopy analyses. The morphology and crystalline phase of the films was investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The YSZ film obtained after heat treatment was dense and crystalline, however, the analyses indicate a significant influence of the solvent and of the substrate temperature during the deposition process on the film morphology.(author)

  14. Doped Organic Transistors.

    Science.gov (United States)

    Lüssem, Björn; Keum, Chang-Min; Kasemann, Daniel; Naab, Ben; Bao, Zhenan; Leo, Karl

    2016-11-23

    Organic field-effect transistors hold the promise of enabling low-cost and flexible electronics. Following its success in organic optoelectronics, the organic doping technology is also used increasingly in organic field-effect transistors. Doping not only increases device performance, but it also provides a way to fine-control the transistor behavior, to develop new transistor concepts, and even improve the stability of organic transistors. This Review summarizes the latest progress made in the understanding of the doping technology and its application to organic transistors. It presents the most successful doping models and an overview of the wide variety of materials used as dopants. Further, the influence of doping on charge transport in the most relevant polycrystalline organic semiconductors is reviewed, and a concise overview on the influence of doping on transistor behavior and performance is given. In particular, recent progress in the understanding of contact doping and channel doping is summarized.

  15. Pyrolysis characteristics of typical biomass thermoplastic composites

    Directory of Open Access Journals (Sweden)

    Hongzhen Cai

    Full Text Available The biomass thermoplastic composites were prepared by extrusion molding method with poplar flour, rice husk, cotton stalk and corn stalk. The thermo gravimetric analyzer (TGA has also been used for evaluating the pyrolysis process of the composites. The results showed that the pyrolysis process mainly consists of two stages: biomass pyrolysis and the plastic pyrolysis. The increase of biomass content in the composite raised the first stage pyrolysis peak temperature. However, the carbon residue was reduced and the pyrolysis efficiency was better because of synergistic effect of biomass and plastic. The composite with different kinds of biomass have similar pyrolysis process, and the pyrolysis efficiency of the composite with corn stalk was best. The calcium carbonate could inhibit pyrolysis process and increase the first stage pyrolysis peak temperature and carbon residue as a filling material of the composite. Keywords: Biomass thermoplastic composite, Calcium carbonate, Pyrolysis characteristic

  16. Influence of Al grain boundaries segregations and La-doping on embrittlement of intermetallic NiAl

    Energy Technology Data Exchange (ETDEWEB)

    Kovalev, Anatoly I., E-mail: a_kovalev@sprg.ru; Wainstein, Dmitry L.; Rashkovskiy, Alexander Yu.

    2015-11-01

    Highlights: • We investigated Al grain boundaries segregations in ordered pure and La-doped NiAl. • Structural segregation of Al decreases critical strain for brittle cracks nucleation. • La alloying sharply improves plasticity of NiAl intermetallic. • Metallicity of interatomic bonds on grain boundaries increases at La alloying. • We have experimentally measured by EELFS that La atoms are located in Al sublattice. - Abstract: The microscopic nature of intergranular fracture of NiAl was experimentally investigated by the set of electron spectroscopy techniques. The paper demonstrates that embrittlement of NiAl intermetallic compound is caused by ordering of atomic structure that leads to formation of structural aluminum segregations at grain boundaries (GB). Such segregations contain high number of brittle covalent interatomic bonds. The alloying by La increases the ductility of material avoiding Al GB enrichment and disordering GB atomic structure. The influence of La alloying on NiAl mechanical properties was investigated. GB chemical composition, atomic and electronic structure transformations after La doping were investigated by AES, XPS and EELFS techniques. To qualify the interatomic bonds metallicity the Fermi level (E{sub F}) position and electrons density (n{sub eff}) in conduction band were determined in both undoped and doped NiAl. Basing on experimental results the physical model of GB brittleness formation was proposed.

  17. Combined influence of hydrostatic pressure and temperature on interband emission energy of impurity doped quantum dots in presence of noise

    Energy Technology Data Exchange (ETDEWEB)

    Bera, Aindrila; Ghosh, Manas, E-mail: pcmg77@rediffmail.com

    2016-11-01

    We explore the profiles of interband emission energy (IEE) of impurity doped quantum dots (QDs) under the simultaneous influence of hydrostatic pressure (HP) and temperature (T) and in presence and absence of Gaussian white noise. Noise has been incorporated to the system additively and multiplicatively. In this regard, modulation of IEE by the variation of several other relevant quantities such as electric field, magnetic field, confinement potential, dopant location, dopant potential and aluminium concentration has also been investigated. Gradual alteration of HP and T affects IEE discernibly. Inclusion of noise has been found to enhance or deplete the IEE depending upon its mode of application. Moreover, under given conditions of temperature and pressure, the difference between the impurity-free ground state energy and the binding energy appears to be crucial in determining whether or not the profiles of IEE would resemble that of binding energy. The findings reveal fascinating role played by noise in tailoring the IEE of doped QD system under conspicuous presence of hydrostatic pressure and temperature. - Highlights: • Interband emission energy (IEE) of doped quantum dot is studied. • Hydrostatic pressure (HP) and temperature (T) affect IEE. • The dot is subjected to Gaussian white noise. • Noise amplifies and suppresses IEE depending on particular condition.

  18. Pyrolysis oil as diesel fuel

    Energy Technology Data Exchange (ETDEWEB)

    Gros, S [Wartsila Diesel International Ltd., Vaasa (Finland). Diesel Technology

    1997-12-31

    Wood waste pyrolysis oil is an attractive fuel alternative for diesel engine operation. The main benefit is the sustainability of the fuel. No fossil reserves are consumed. The fact that wood waste pyrolysis oil does not contribute to CO{sub 2} emissions is of utmost importance. This means that power plants utilising pyrolysis oil do not cause additional global warming. Equally important is the reduced sulphur emissions that this fuel alternative implies. The sulphur content of pyrolysis oil is extremely low. The high water content and low heating value are also expected to result in very low NO{sub x} emissions. Utilisation of wood waste pyrolysis oil in diesel engines, however, involves a lot of challenges and problems to be solved. The low heating value requires a new injection system with high capacity. The corrosive characteristics of the fluid also underline the need for new injection equipment materials. Wood waste pyrolysis oil contains solid particles which can clog filters and cause abrasive wear. Wood waste pyrolysis oil has proven to have extremely bad ignition properties. The development of a reliable injection system which is able to cope with such a fuel involves a lot of optimisation tests, redesign and innovative solutions. Successful single-cylinder tests have already been performed and they have verified that diesel operation on wood pyrolysis oil is technically possible. (orig.)

  19. Time resolved pyrolysis of char

    DEFF Research Database (Denmark)

    Egsgaard, H.; Ahrenfeldt, J.; Henriksen, U.B.

    pyrolysis, and slow heating in direct combination with mass spectrometry, gas chromatography/mass spectrometry and flame ionization detection, respectively. Characteristic ions derived from the flash pyrolysis-gas chromatography/mass spectrometry data enable the release of volatiles to be time and, hence...

  20. Pyrolysis oil as diesel fuel

    Energy Technology Data Exchange (ETDEWEB)

    Gros, S. [Wartsila Diesel International Ltd., Vaasa (Finland). Diesel Technology

    1996-12-31

    Wood waste pyrolysis oil is an attractive fuel alternative for diesel engine operation. The main benefit is the sustainability of the fuel. No fossil reserves are consumed. The fact that wood waste pyrolysis oil does not contribute to CO{sub 2} emissions is of utmost importance. This means that power plants utilising pyrolysis oil do not cause additional global warming. Equally important is the reduced sulphur emissions that this fuel alternative implies. The sulphur content of pyrolysis oil is extremely low. The high water content and low heating value are also expected to result in very low NO{sub x} emissions. Utilisation of wood waste pyrolysis oil in diesel engines, however, involves a lot of challenges and problems to be solved. The low heating value requires a new injection system with high capacity. The corrosive characteristics of the fluid also underline the need for new injection equipment materials. Wood waste pyrolysis oil contains solid particles which can clog filters and cause abrasive wear. Wood waste pyrolysis oil has proven to have extremely bad ignition properties. The development of a reliable injection system which is able to cope with such a fuel involves a lot of optimisation tests, redesign and innovative solutions. Successful single-cylinder tests have already been performed and they have verified that diesel operation on wood pyrolysis oil is technically possible. (orig.)

  1. Influence of iridium doping in MgB2 superconducting wires

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude

    2018-01-01

    MgB2 wires with iridium doping were manufactured using the in-situ technique in a composite Cu-Nb sheath. Reaction was performed at 700°C, 800°C or 900°C for 1h in argon atmosphere. A maximum of about 1.5 at.% Ir replaces Mg in MgB2. The superconducting transition temperature is slightly lowered...... by Ir doping. The formation of IrMg3 and IrMg4 secondary phase particles is evidenced, especially for a nominal stoichiometry with 2.0 at.% Ir doping. The critical current density and accommodation field of the wires are strongly dependent on the Ir content and are generally weakened in the presence...

  2. Influence of small metallic particles on the absorption and emission in amorphous materials doped with rare earths

    International Nuclear Information System (INIS)

    Malta, O.L.; Santa Cruz, P.A.; Sa, G.F. de

    1987-01-01

    The influence of small metallic clusters on the absorption and emission processes in molecular species shows a great interest as well the fundamental as the pratical point of view. This subject, which has been recently developed, covers several aspects related to the kinetics of formation of these chusters and to theirs optical properties in amorphous media. A study of this problem developed by the first time for the case of one volumetric distribution of metallic particles is presented. With this aim, fluoborate glasses doped with Eu 3+ ion which fluorescence is well known in several materials are used. (L.C.) [pt

  3. Influence of gamma-ray irradiation on Faraday effect of Cu-doped germano-silicate optical fiber

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Youngwoong; Ju, Seongmin; Jeong, Seongmook; Jang, Myoung-Jin [Department of Physics and Photon Science, School of Information and Communications, Gwangju Institute of Science and Technology, 261 Cheomdan-gwagiro, Buk-Gu, Gwangju 500-712 (Korea, Republic of); Kim, Jong-Yeol; Lee, Nam-Ho; Jung, Hyun-Kyu [Nuclear Convergence Technology Development Department, Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejeon (Korea, Republic of); Han, Won-Taek, E-mail: wthan@gist.ac.kr [Department of Physics and Photon Science, School of Information and Communications, Gwangju Institute of Science and Technology, 261 Cheomdan-gwagiro, Buk-Gu, Gwangju 500-712 (Korea, Republic of)

    2015-02-01

    Influence of gamma-ray irradiation on the Faraday effect of the Cu-doped germano-silicate optical fiber was investigated. The Verdet constant of the gamma-ray irradiated optical fiber at 660 nm was measured to be 3.07 rad T{sup −1} m{sup −1}, 1.46 times larger than that of before the irradiation at total dose of 1200 Gy. Cu-related radiation-induced defect centers and Cu metal particles which were reduced from Cu{sup 2+} ions by the irradiation are thought to be responsible for the increase in the Verdet constant of the optical fiber.

  4. Improvement of the optoelectronic properties of tin oxide transparent conductive thin films through lanthanum doping

    Energy Technology Data Exchange (ETDEWEB)

    Mrabet, C., E-mail: chokri.mrabet@hotmail.com; Boukhachem, A.; Amlouk, M.; Manoubi, T.

    2016-05-05

    thin films are promising to be useful in various optoelectronic applications. - Highlights: • La-doped SnO{sub 2} has been synthesized by the facile spray pyrolysis method. • Influences of doping on the electrical and optical properties of the films were investigated. • La doped SnO{sub 2} films exhibit high transparency in the visible range and low sheet resistance. • The calculated values of Haacke's figure of merit show that La doping improves the optoelectronic properties of SnO{sub 2}. • A new figure of merit has been introduced to qualify the photo-thermal conversion applications.

  5. Influence of microgravity on Ce-doped Bi12 SiO20 crystal defect

    Indian Academy of Sciences (India)

    TECS

    studied by comparing space grown BSO crystal with ground grown one. These results show ... fractive properties (Aldrich et al 1971; Peltier and. Micheron ... The shape of interface changes from concave to convex by suppressing ... cations. Figure 1. Parts of Ce doped BSO crystals: (a) space growth and (b) ground growth.

  6. Influence of silver doping on surface defect characteristics of TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Tripathi, S. K., E-mail: surya@pu.ac.in [Department of Physics, Center of Advanced Study in Physics, Panjab University, Chandigarh-160 014 (India); Rani, Mamta [Department of Physics, Center of Advanced Study in Physics, Panjab University, Chandigarh-160 014 (India); Department of Physics, DAV University Jalandhar, - 144 001, Punjab (India)

    2015-08-28

    In the present work, we proposed a novel silver doped TiO{sub 2} polyethylene conjugated films to improve the performance of DSSCs. Oxides nanoparticles dispersed in a semiconducting polymer form the active layer of a solar cell. Localized surface plasmon resonance effects associated with spatially dispersed silver (Ag) nanoparticles can be exploited to enhance the light-harvesting efficiency, the photocurrent density and the overall light-to electrical-energy-conversion efficiency of high-area DSSCs based TiO{sub 2} photoanodes. Silver doped titanium dioxide (TiO{sub 2}:Ag) is prepared by sol-gel technique and deposited on fluorine doped indium oxide (FTO) coated glass substrates by using doctor blade technique at 550°C from aqueous solutions of titanium butoxide and silver nitrate precursors. The effect of Ag doping on electrical properties of films is studied. The Ag-TiO{sub 2} films are about 548 times more photosensitive as compare to the pure TiO{sub 2} sample. The presence of metallic Ag nanoparticles and oxygen vacancy on the surface of TiO{sub 2} nanoparticles promotes the separation of photogenerated electron-hole pairs and thus enhances the photosensitivity. Photoconduction mechanism of all prepared samples is investigated by performing transient photoconductivity measurements on TiO{sub 2} and Ag-TiO{sub 2} films keeping intensity of light constant.

  7. Radiation effects on erbium doped optical fibers: on the influence of the fiber composition

    International Nuclear Information System (INIS)

    Tortech, B.

    2008-01-01

    We have studied the erbium-doped fibers (EDF) sensitivity under irradiation and the induced defects. The first chapter presents the state of the art for the EDF under irradiation as well as some radiation generated silica defects. The second chapter details the radiations used in this thesis and the experimental set-ups implemented for the characterization of the fiber responses under irradiation and the radiation induced defects. In the third chapter, we present the response of several erbium-doped fibers irradiated with γ-rays, protons and pulsed X-rays. The erbium doped fibers have higher radiation induced sensitivity than the Telecom fibers (SMF28) or than erbium-doped fibers containing little aluminum. The aluminum presence in the EDF core composition is mainly responsible for the fiber performance degradation. Whatever the irradiation types, the radiation generated defects are related to the host matrix. Our studies also display that the erbium ions are only affected by the interaction with the created defects. The fourth chapter deals with the EDF under UV exposure and shows that the UV rays lead to the same effects than the gamma rays. The last chapter of this thesis presents the study of optical fiber amplifiers under γ irradiation. (author)

  8. Factors influencing voltammetric reduction of 5-nitroquinoline at boron-doped diamond electrodes

    Czech Academy of Sciences Publication Activity Database

    Vosáhlová, J.; Zavázalová, J.; Petrák, Václav; Schwarzová-Pecková, K.

    2016-01-01

    Roč. 147, č. 1 (2016), s. 21-29 ISSN 0026-9247 Institutional support: RVO:68378271 Keywords : voltammetry * boron-doped diamond electrode * boron concentration * reduction * electrochemistry Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 1.282, year: 2016

  9. Influence of Promotor, H2O and H2S on the Hydrodeoxygenation of Biomass Pyrolysis Vapor over MoS2 Catalysts

    DEFF Research Database (Denmark)

    Arndal, Trine M. H.; Høj, Martin; Gaur, Abhijeet

    Catalytic hydropyrolysis combines fast pyrolysis with catalytic upgrading by hydrodeoxygenation (HDO) in a single step for the production of fuel oil from biomass in which reactive pyrolysis vapors are upgraded before condensation. Catalyst activity and lifetime is challenged by carbon deposition...

  10. Study of the potential valorisation of heavy metal contaminated biomass via phytoremediation by fast pyrolysis: Part I. Influence of temperature, biomass species and solid heat carrier on the behaviour of heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    C. Lievens; J. Yperman; J. Vangronsveld; R. Carleer [Hasselt University, Diepenbeek (Belgium). Laboratory of Applied Chemistry

    2008-08-15

    Presently, little or no information of implementing fast pyrolysis for looking into the potential valorisation of heavy metal contaminated biomass is available. Fast pyrolysis of heavy metal contaminated biomass (birch and sunflower), containing high amounts of Cd, Cu, Pb and Zn, resulting from phytoremediation, is investigated. The effect of the pyrolysis temperature (623, 673, 773 and 873 K) and the type of solid heat carrier (sand and fumed silica) on the distribution of the heavy metals in birch and sunflower pyrolysis fractions are studied. The goal of the set-up is 'concentrating' heavy metals in the ash/char fraction after thermal treatment, preventing them to be released in the condensable and/or volatile fractions. The knowledge of the behaviour of heavy metals affects directly future applications and valorisation of the pyrolysis products and thus contaminated biomass. They are indispensable for making and selecting the proper thermal conditions for their maximum recovery. In view of the future valorisation of these biomasses, the amounts of the pyrolysis fractions and the calorific values of the obtained liquid pyrolysis products, as a function of the pyrolysis temperature, are determined. 46 refs., 8 figs., 4 tabs.

  11. Influence of Zn doping on structural, optical and dielectric properties of LaFeO3

    Science.gov (United States)

    Manzoor, Samiya; Husain, Shahid

    2018-05-01

    The effect of Zn doping on structural, optical and dielectric properties of nano-crystalline LaFe1‑xZnxO3 (0.0 ≤ x ≤ 0.3) samples have been investigated. These samples are synthesized using conventional solid state reaction route. X-ray diffraction patterns with Rietveld analysis confirm the single phase nature of samples. Further, the sample formation has been confirmed by FTIR spectroscopy. All the samples are formed in orthorhombic crystal symmetry with Pbnm space group. The average crystallite sizes, calculated from the Scherer’s formula, lie in the range below 50 nm. Rietveld refinement technique is used to determine lattice parameters, bond lengths and unit cell volume. Williamson-Hall analysis has been performed to calculate the crystallite size and lattice strain. Crystallite sizes are found to be of nanometer range while the strain is of the order of 10‑3. Zn doping leads to the expansion of volume due to the tensile strain. Optical bandgap has been determined from Kubelka-Munk function using Tauc’s relation. Zinc doping in LaFeO3 leads to decrease in optical bandgap. Dielectric constant as a function of frequency is measured in the frequency range of 75 kHz–5 MHz. The dielectric behavior has been investigated by analyzing ‘universal dielectric response’ (UDR) model. The dielectric constant (ε‧) shows colossal value with Zn doping in the whole frequency range. However, the imaginary part (ε″) shows relaxational behavior which may be attributed to the strong correlation that exists between conduction mechanism and dielectric behavior in ferrites. Cole-Cole analysis has been done that confirms the dielectric material does not follow the ideal Debye theory but shows distribution of relaxation times. The a.c conductivity increases with frequency and with Zn doping due to the increased polaron hopping.

  12. The influence of oxygen and nitrogen doping on GeSbTe phase-change optical recording media properties

    Energy Technology Data Exchange (ETDEWEB)

    Dimitrov, D.; Shieh, H.-P.D

    2004-03-15

    Nitrogen and oxygen doped and co-doped GeSbTe (GST) films for phase-change optical recording are investigated. It is found that the crystallization temperature increased as well as the crystalline microstructure refined by doping. The carrier-to-noise ratio (CNR) and erasability of phase-change optical disks are improved being up to 52 and 35 dB, respectively, by using an appropriate nitrogen doping or co-doping concentration in the recording layer. Optical disks with co-doped recording layer are found to be superior in the recording characteristics then the single doped recording layer disks.

  13. Pyrolysis characteristics of typical biomass thermoplastic composites

    Science.gov (United States)

    Cai, Hongzhen; Ba, Ziyu; Yang, Keyan; Zhang, Qingfa; Zhao, Kunpeng; Gu, Shiyan

    The biomass thermoplastic composites were prepared by extrusion molding method with poplar flour, rice husk, cotton stalk and corn stalk. The thermo gravimetric analyzer (TGA) has also been used for evaluating the pyrolysis process of the composites. The results showed that the pyrolysis process mainly consists of two stages: biomass pyrolysis and the plastic pyrolysis. The increase of biomass content in the composite raised the first stage pyrolysis peak temperature. However, the carbon residue was reduced and the pyrolysis efficiency was better because of synergistic effect of biomass and plastic. The composite with different kinds of biomass have similar pyrolysis process, and the pyrolysis efficiency of the composite with corn stalk was best. The calcium carbonate could inhibit pyrolysis process and increase the first stage pyrolysis peak temperature and carbon residue as a filling material of the composite.

  14. Influence of Oxygenated Compounds on Reaction Products in a Microwave Plasma Methane Pyrolysis Assembly for Post-Processing of Sabatier Methane

    Science.gov (United States)

    Mansell, J. Matthew; Abney, Morgan B.

    2012-01-01

    The state-of-the-art Carbon Dioxide Reduction Assembly (CRA) was delivered to the International Space Station (ISS) in April 2010. The system is designed to accept carbon dioxide from the Carbon Dioxide Removal Assembly and hydrogen from the Oxygen Generation Assembly. The two gases are reacted in the CRA in a Sabatier reactor to produce water and methane. Venting of methane results in an oxygen resupply requirement of about 378 lbs per crew member per year. If the oxygen is supplied as water, the total weight for resupply is about 476 lb per crew member per year. For long-term missions beyond low Earth orbit, during which resupply capabilities will be further limited, recovery of hydrogen from methane is highly desirable. For this purpose, NASA is pursuing development of a Plasma Pyrolysis Assembly (PPA) capable of recovering hydrogen from methane. Under certain conditions, water vapor and carbon dioxide (nominally intended to be separated from the CRA outlet stream) may be present in the PPA feed stream. Thus, testing was conducted in 2010 to determine the effect of these oxygenated compounds on PPA performance, particularly the effect of inlet carbon dioxide and water variations on the PPA product stream. This paper discusses the test set-up, analysis, and results of this testing.

  15. Influence of Advanced Injection Timing and Fuel Additive on Combustion, Performance, and Emission Characteristics of a DI Diesel Engine Running on Plastic Pyrolysis Oil

    Directory of Open Access Journals (Sweden)

    Ioannis Kalargaris

    2017-01-01

    Full Text Available This paper presents the investigation of engine optimisation when plastic pyrolysis oil (PPO is used as the primary fuel of a direct injection diesel engine. Our previous investigation revealed that PPO is a promising fuel; however the results suggested that control parameters should be optimised in order to obtain a better engine performance. In the present work, the injection timing was advanced, and fuel additives were utilised to overcome the issues experienced in the previous work. In addition, spray characteristics of PPO were investigated in comparison with diesel to provide in-depth understanding of the engine behaviour. The experimental results on advanced injection timing (AIT showed reduced brake thermal efficiency and increased carbon monoxide, unburned hydrocarbons, and nitrogen oxides emissions in comparison to standard injection timing. On the other hand, the addition of fuel additive resulted in higher engine efficiency and lower exhaust emissions. Finally, the spray tests revealed that the spray tip penetration for PPO is faster than diesel. The results suggested that AIT is not a preferable option while fuel additive is a promising solution for long-term use of PPO in diesel engines.

  16. Pyrolysis of Lantana camara and Mimosa pigra: Influences of temperature, other process parameters and incondensable gas evolution on char yield and higher heating value.

    Science.gov (United States)

    Mundike, Jhonnah; Collard, François-Xavier; Görgens, Johann F

    2017-11-01

    Pyrolysis of invasive non-indigenous plants, Lantana camara (LC) and Mimosa pigra (MP) was conducted at milligram-scale for optimisation of temperature, heating rate and hold time on char yield and higher heating value (HHV). The impact of scaling-up to gram-scale was also studied, with chromatography used to correlate gas composition with HHV evolution. Statistically significant effects of temperature on char yield and HHV were obtained, while heating rate and hold time effects were insignificant. Milligram-scale maximised HHVs were 30.03MJkg -1 (525°C) and 31.01MJkg -1 (580°C) for LC and MP, respectively. Higher char yields and HHVs for MP were attributed to increased lignin content. Scaling-up promoted secondary char formation thereby increasing HHVs, 30.82MJkg -1 for LC and 31.61MJkg -1 for MP. Incondensable gas analysis showed that temperature increase beyond preferred values caused dehydrogenation that decreased HHV. Similarly, CO evolution profile explained differences in optimal HHV temperatures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Enhancing biochar yield by co-pyrolysis of bio-oil with biomass: impacts of potassium hydroxide addition and air pretreatment prior to co-pyrolysis.

    Science.gov (United States)

    Veksha, Andrei; Zaman, Waheed; Layzell, David B; Hill, Josephine M

    2014-11-01

    The influence of KOH addition and air pretreatment on co-pyrolysis (600 °C) of a mixture of bio-oil and biomass (aspen wood) was investigated with the goal of increasing biochar yield. The bio-oil was produced as a byproduct of the pyrolysis of biomass and recycled in subsequent runs. Co-pyrolysis of the biomass with the recycled bio-oil resulted in a 16% mass increase in produced biochar. The yields were further increased by either air pretreatment or KOH addition prior to co-pyrolysis. Air pretreatment at 220 °C for 3 h resulted in the highest mass increase (32%) compared to the base case of pyrolysis of biomass only. No synergistic benefit was observed by combining KOH addition with air pretreatment. In fact, KOH catalyzed reactions that increased the bed temperature resulting in carbon loss via formation of CO and CO2. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Co-Pyrolysis Behaviors of the Cotton Straw/PP Mixtures and Catalysis Hydrodeoxygenation of Co-Pyrolysis Products over Ni-Mo/Al2O3 Catalyst

    Directory of Open Access Journals (Sweden)

    Derun Hua

    2015-12-01

    Full Text Available The doping of PP (polypropylene with cotton straw improved the bio-oil yield, which showed there was a synergy in the co-pyrolysis of the cotton straw and PP at the range of 380–480 °C. In a fixed-bed reactor, model compounds and co-pyrolysis products were used for reactants of hydrodeoxygenation (HDO over Ni-Mo/Al2O3. The deoxygenation rate of model compounds decreased over Ni-Mo/Al2O3 in the following order: alcohol > aldehyde > acetic acid > ethyl acetate. The upgraded oil mainly consisted of C11 alkane.

  19. Vanadia-based SCR Catalysts Supported on Tungstated and Sulfated Zirconia: Influence of Doping with Potassium

    DEFF Research Database (Denmark)

    Due-Hansen, Johannes; Boghosian, Soghomon; Kustov, Arkadii

    2007-01-01

    A series of vanadium-based SCR catalysts supported on sulfated or tungstated ZrO2 were synthesized and characterized by means of N2-BET, XRD, NH3-TPD and in situ Raman spectroscopy. The effect of potassium doping on the properties of vanadia species is studied in detail. A number of catalyst...... and morphology, the surface composition and the molecular configuration of the dispersed vanadates. It was observed that poisoning with potassium had a negligible effect on the surface vanadate species (especially the V=O stretching frequency observed by in situ Raman spectroscopy) if supported on the sulfated...... the observed decrease in V=O stretching frequency and the higher proportion of dimers and higher polymers through coordination between K+ and two neighbouring V=O. The results suggest an increased resistance towards potassium doping for the vanadia-based catalysts supported on sulfated zirconia....

  20. Influence of Sc doping concentration on electronic structure and optical properties of ZnO

    International Nuclear Information System (INIS)

    Wu Yuxi; Zhang Hao; Han Long; Qu Licheng; Gu Shulin; Li Teng

    2011-01-01

    In this paper, we adopt the density functional theory (DFT) plane wave pseudopotential method to study the crystal structure, electronic structure and optical property for the different concentrations of Sc doped ZnO system. We optimize the structure of Sc and get the basis of numerical simulation. The results show that with the adoption of Sc, the lattice constants of the system increase gradually, the energy of the system becomes larger, the Fermi level enters into the conduction band, the system shows Metallic gradually and the band gap becomes wider. On the other hand, certain changes of the optical properties of doped ZnO have taken place, i. e., a new absorption peak happens in ZnO absorption spectrum and the blue shift of absorption edge with the new peak occurs in the imagery part of dielectric function. (authors)

  1. Influence of Te and Se doping on ZnO films growth by SILAR method

    Science.gov (United States)

    Güney, Harun; Duman, Ćaǧlar

    2016-04-01

    The AIP Successive ionic layer adsorption and reaction (SILAR) is an economic and simple method to growth thin films. In this study, SILAR method is used to growth Selenium (Se) and Tellurium (Te) doped zinc oxide (ZnO) thin films with different doping rates. For characterization of the films X-ray diffraction (XRD), absorbance and scanning electron microscopy (SEM) are used. XRD results are showed well-defined strongly (002) oriented crystal structure for all samples. Also, absorbance measurements show, Te and Se concentration are proportional and inversely proportional with band gap energy, respectively. SEM measurements show that the surface morphology and thickness of the material varied with Se and/or Te and varying concentrations.

  2. Influence of Te and Se doping on ZnO films growth by SILAR method

    International Nuclear Information System (INIS)

    Güney, Harun; Duman, Çağlar

    2016-01-01

    The AIP Successive ionic layer adsorption and reaction (SILAR) is an economic and simple method to growth thin films. In this study, SILAR method is used to growth Selenium (Se) and Tellurium (Te) doped zinc oxide (ZnO) thin films with different doping rates. For characterization of the films X-ray diffraction (XRD), absorbance and scanning electron microscopy (SEM) are used. XRD results are showed well-defined strongly (002) oriented crystal structure for all samples. Also, absorbance measurements show, Te and Se concentration are proportional and inversely proportional with band gap energy, respectively. SEM measurements show that the surface morphology and thickness of the material varied with Se and/or Te and varying concentrations.

  3. Influence of Te and Se doping on ZnO films growth by SILAR method

    Energy Technology Data Exchange (ETDEWEB)

    Güney, Harun, E-mail: harunguney25@hotmail.com [Department of Electric and Energy, Vocation High School, Ağrı İbrahim Çeçen University (Turkey); Duman, Çağlar, E-mail: caglarduman@erzurum.edu.tr [Department of Electrical and Electronic Engineering, Faculty of Engineering, Erzurum Technical University (Turkey)

    2016-04-18

    The AIP Successive ionic layer adsorption and reaction (SILAR) is an economic and simple method to growth thin films. In this study, SILAR method is used to growth Selenium (Se) and Tellurium (Te) doped zinc oxide (ZnO) thin films with different doping rates. For characterization of the films X-ray diffraction (XRD), absorbance and scanning electron microscopy (SEM) are used. XRD results are showed well-defined strongly (002) oriented crystal structure for all samples. Also, absorbance measurements show, Te and Se concentration are proportional and inversely proportional with band gap energy, respectively. SEM measurements show that the surface morphology and thickness of the material varied with Se and/or Te and varying concentrations.

  4. Influence of Tm-doping on microstructure and luminescence behavior of barium strontium titanate thick films

    International Nuclear Information System (INIS)

    Wang Jingyang; Zhang Tianjin; Pan Ruikun; Ma Zhijun; Wang Jinzhao

    2012-01-01

    Tm-doped Ba 0.8 Sr 0.2 TiO 3 thick films were prepared by the screen-printing technique on the alumina substrate. The microstructure of the Tm-doped BST thick films was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Raman spectroscopy, respectively. All the samples showed a typical perovskite polycrystalline structure when sintered at 1260 °C. The substitution behavior of Tm 3+ ion in BST was found to change with increasing the Tm 3+ concentration. The observed Tm-related red emission reaches the maximum at 0.2 mol% Tm 3+ concentration. The effects of concentration quenching on the luminescence intensity were discussed.

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

    International Nuclear Information System (INIS)

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

    2015-01-01

    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 Gd 2 O 3 :Eu 3+ @Fe 2 O 3 particles by ultrasonic spray pyrolysis performed in a tubular furnace. In order to achieve the composite formation, commercial superparamagnetic Fe 3 O 4 nanoparticles were coated with a luminescent Eu 3+ -doped Gd 2 O 3 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 (λ Exc = 265 nm) of the magnetic Gd 2 O 3 :Eu 3+ @Fe 2 O 3 compound showed the characteristic red emission of Eu 3+ (λ Em = 612 nm). This magneto/luminescent system will find applications in biomedicine and biotechnology. (paper)

  6. Pyrolysis and oxidative pyrolysis experiments with organization exchange resin

    International Nuclear Information System (INIS)

    Chun, Ung Kyung

    1997-01-01

    Pyrolysis may be an important pretreatment step before vitrification in a cold crucible melter (CCM). During vitrification of organic resin the carbon or other remaining residues may harm the performance of the cold crucible melter of the eventual stability of the final glass product. Hence, it is important to reduce or prevent such harmful waste from entry into the cold crucible melter. Pretreatment with pyrolysis will generally provide volume reduction resulting in less amount of solid waste that needs to be handled by the CCM; in addition, the pyrolytic processes may breakdown much of the complex organics causing release through volatilization resulting in less carbon and other harmful substances. Hence, KEPRI has undertaken studies on the pyrolysis and oxidative pyrolysis of organic ion exchange resin. Pyrolysis and oxidative pyrolysis were examined with TGA and a tube furnace. TGA results for pyrolysis with the flow of nitrogen indicate that even after pyrolyzing from room temperature to about 900 deg C, a significant mass fraction of the original cationic resin remains, approximately 46 %. The anionic resin when pyrolytically heated in a flow of nitrogen only, from room temperature to about 900 deg C, produced a final residue mass fraction of about 8 percent. Oxidation at a ratio of air to nitrogen, 1:2, reduced the cationic resin to 5.3% when heated at 5 C/min. Oxidation of anionic resin at the same ratio and same heating rate left almost no solid residue. Pyrolysis (e.g. nitrogen-only environment) in the tube furnace of larger samples relative to the TGA produced very similar results to the TGA. The differences may be attributed to the scale effects such as surface area exposure to the gas stream, temperature distributions throughout the resin, etc. (author) 7 refs., 7 figs

  7. Pyrolysis and oxidative pyrolysis experiments with organization exchange resin

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Ung Kyung [Korea Electric Power Research Insititute, Taejon (Korea, Republic of)

    1997-12-31

    Pyrolysis may be an important pretreatment step before vitrification in a cold crucible melter (CCM). During vitrification of organic resin the carbon or other remaining residues may harm the performance of the cold crucible melter of the eventual stability of the final glass product. Hence, it is important to reduce or prevent such harmful waste from entry into the cold crucible melter. Pretreatment with pyrolysis will generally provide volume reduction resulting in less amount of solid waste that needs to be handled by the CCM; in addition, the pyrolytic processes may breakdown much of the complex organics causing release through volatilization resulting in less carbon and other harmful substances. Hence, KEPRI has undertaken studies on the pyrolysis and oxidative pyrolysis of organic ion exchange resin. Pyrolysis and oxidative pyrolysis were examined with TGA and a tube furnace. TGA results for pyrolysis with the flow of nitrogen indicate that even after pyrolyzing from room temperature to about 900 deg C, a significant mass fraction of the original cationic resin remains, approximately 46 %. The anionic resin when pyrolytically heated in a flow of nitrogen only, from room temperature to about 900 deg C, produced a final residue mass fraction of about 8 percent. Oxidation at a ratio of air to nitrogen, 1:2, reduced the cationic resin to 5.3% when heated at 5 C/min. Oxidation of anionic resin at the same ratio and same heating rate left almost no solid residue. Pyrolysis (e.g. nitrogen-only environment) in the tube furnace of larger samples relative to the TGA produced very similar results to the TGA. The differences may be attributed to the scale effects such as surface area exposure to the gas stream, temperature distributions throughout the resin, etc. (author) 7 refs., 7 figs.

  8. Influence of Lanthanum Doping on the Structural and Optical Properties of Hematite Nanopowders

    Science.gov (United States)

    Justus, J. Sharmila; Dharma Roy, S. Dawn; Raj, A. Moses Ezhil

    2016-10-01

    Rare-earth elements are an attractive class of dopant elements, as they give easily trivalent cations that possibly altering the structure and other properties of the parent nanoparticles and creating multifunctional materials because of their f-electronic configurations. Herein, experimental evidence has been given for a better understanding of the factors that dictate the interactions of La doping on the structure and optical properties of iron oxide nanoparticles. For that, lanthanum doped hematite (α-Fe2O3) nanoparticles were prepared by a facile solution method using iron (III) chloride (FeCl3) as starting precursor and sodium hydroxide (NaOH) as reducing agent without templates at low temperature. As-prepared powders were subsequently calcined in air for 3 hr at 800 °C. Xray diffraction (XRD) technique was used to study the nanocrystal formation of α-Fe2O3 and Fourier Transform Raman (FT-Raman) spectral information identified the chemical bond structure of the nanoparticles. Morphology study of the nanoparticles was identified using Scanning Electron Microscope (SEM) and the incorporated La content was recognized from the Energy Dispersive X-ray Spectroscopy (EDS) analysis. The optical absorption spectrum was recorded in the wavelength range of 200-2000 nm and the optical parameters such as absorption coefficient and optical band gap energy of pure and doped Fe2O3 nanoparticles were determined. Obtained results are interpreted by considering the impregnation of trivalent La cations that replaced Fe cations of the host structure.

  9. Pyrolysis of superfine pulverized coal. Part 3. Mechanisms of nitrogen-containing species formation

    International Nuclear Information System (INIS)

    Liu, Jiaxun; Jiang, Xiumin; Shen, Jun; Zhang, Hai

    2015-01-01

    Highlights: • NH 3 and NO formation mechanisms during superfine pulverized coal pyrolysis are investigated. • Influences of temperature, heating rate, particle size, atmosphere, and acid wash on the NH 3 and NO formation are analyzed. • Transformations of nitrogen-containing structures in coal/char during pyrolysis are recognized through XPS observation. • Relationships among nitrogen-containing gaseous species during pyrolysis are discussed. - Abstract: With more stringent regulations being implemented, elucidating the formation mechanisms of nitrogen-containing species during the initial pyrolysis step becomes important for developing new NO x control strategies. However, there is a lack of agreement on the origins of NO x precursors during coal pyrolysis, in spite of extensive investigations. Hence, it is important to achieve a more precise knowledge of the formation mechanisms of nitrogen-contain species during coal pyrolysis. In this paper, pyrolysis experiments of superfine pulverized coal were performed in a fixed bed at low heating rates. The influences of temperature, coal type, particle size and atmosphere on the NH 3 and NO evolution were discussed. There is a central theme to develop knowledge of the relationship between particle sizes and evolving behaviors of nitrogen-containing species. Furthermore, the catalytic role of inherent minerals in coal was proved to be effective on the partitioning of nitrogen during coal pyrolysis. In addition, the conversion pathways of heteroaromatic nitrogen structures in coal/char during pyrolysis were recognized through the X-ray photoelectron spectroscopy (XPS) analysis. Large quantities of pyridinic and quanternary nitrogen functionalities were formed during the thermal degradation. Finally, the relationships among the nitrogen-containing gaseous species during coal pyrolysis were discussed. In brief, a comprehensive picture of the volatile-nitrogen partitioning during coal pyrolysis is obtained in this

  10. Influence of the carbon-doping location on the material and electrical properties of a AlGaN/GaN heterostructure on Si substrate

    International Nuclear Information System (INIS)

    Ni, Yiqiang; Zhou, Deqiu; Chen, Zijun; Zheng, Yue; He, Zhiyuan; Yang, Fan; Yao, Yao; Zhou, Guilin; Shen, Zhen; Zhong, Jian; Zhang, Baijun; Liu, Yang; Wu, Zhisheng

    2015-01-01

    The influence of different C-doping locations in a GaN/Si structure with a GaN/AlN superlattice (SL) buffer on the material and electrical properties of GaN/Si was studied. The introduction of C doping can remarkably degrade the crystal quality of the buffer. C-doping of a top GaN buffer can introduce compressive stress into the top GaN due to the size effect, while C-doping in a SL buffer can impair the compressive stress provided from the SL buffer to the top GaN. It is found that introducing high-density carbon into the whole buffer can result in a more strain-balanced GaN/Si system with small deterioration of the 2DEG channel. Furthermore, the whole buffer C-doping method is an effective and easy way to achieve a thin buffer with low leakage current and high breakdown voltage (266 V@1 nA mm −1 ; 698 V@10 μA mm −1 ; 912 V@1 mA mm −1 ). By using the whole-buffer C-doping method, a 2.5 μm-thick AlGaN/GaN HFET with a breakdown voltage higher than 900 V was achieved, and the breakdown voltage per unit buffer thickness can reach 181 V μm −1 . (paper)

  11. Simultaneous influence of hydrostatic pressure and temperature on diamagnetic susceptibility of impurity doped quantum dots under the aegis of noise

    International Nuclear Information System (INIS)

    Saha, Surajit; Ganguly, Jayanta; Bera, Aindrila; Ghosh, Manas

    2016-01-01

    Highlights: • Diamagnetic susceptibility (DMS) of doped quantum dot is studied. • Hydrostatic pressure (HP) and temperature (T) affect DMS. • The dot is subjected to Gaussian white noise. • DMS also depends on mode of application of noise. - Abstract: We explore the diamagnetic susceptibility (DMS) of impurity doped quantum dot (QD) in presence of Gaussian white noise and under the combined influence of hydrostatic pressure (HP) and temperature (T). Presence of noise and also its mode of application discernibly affect the DMS profile. Application of HP and T invites greater delicacies in the observed DMS profiles. However, whereas the interplay between T and noise comes out to be extremely sensitive in fabricating the DMS profile, the pressure-noise interplay appears to be not that much noticeable. Under all conditions of temperature and pressure, the presence of multiplicative noise diminishes the value of DMS in comparison with that in presence of its additive analogue. The present study renders a deep insight into the remarkable role played by the interplay between noise, hydrostatic pressure and temperature in controlling the effective confinement imposed on the system which bears unquestionable relevance.

  12. [Influence of deposition time on chromatics during nitrogen-doped diamond like carbon coating on pure titanium].

    Science.gov (United States)

    Yin, Lu; Yao, Jiang-wu; Xu, De-wen

    2010-10-01

    The aim of this study was to observed the influence of deposition time on chromatics during nitrogen-doped diamond like carbon coating (N-DLC) on pure titanium by multi impulse are plasma plating machine. Applying multi impulse are plasma plating machine to produce TiN coatings on pure titanium in nitrogen atmosphere, then filming with nitrogen-doped DLC on TiN in methane (10-80 min in every 5 min). The colors of N-DLC were evaluated in the CIE1976 L*a*b* uniform color scale and Mussell notation. The surface morphology of every specimen was analyzed using scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). When changing the time of N-DLC coating deposition, N-DLC surface showed different color. Golden yellow was presented when deposition time was 30 min. SEM showed that crystallization was found in N-DLC coatings, the structure changed from stable to clutter by varying the deposition time. The chromatics of N-DLC coatings on pure titanium could get golden yellow when deposition time was 30 min, then the crystallized structure was stable.

  13. Simultaneous influence of hydrostatic pressure and temperature on diamagnetic susceptibility of impurity doped quantum dots under the aegis of noise

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Surajit [Department of Chemistry, Physical Chemistry Section, Visva Bharati University, Santiniketan, Birbhum 731 235, West Bengal (India); Ganguly, Jayanta [Department of Chemistry, Brahmankhanda Basapara High School, Basapara, Birbhum 731215, West Bengal (India); Bera, Aindrila [Department of Chemistry, Physical Chemistry Section, Visva Bharati University, Santiniketan, Birbhum 731 235, West Bengal (India); Ghosh, Manas, E-mail: pcmg77@rediffmail.com [Department of Chemistry, Physical Chemistry Section, Visva Bharati University, Santiniketan, Birbhum 731 235, West Bengal (India)

    2016-11-30

    Highlights: • Diamagnetic susceptibility (DMS) of doped quantum dot is studied. • Hydrostatic pressure (HP) and temperature (T) affect DMS. • The dot is subjected to Gaussian white noise. • DMS also depends on mode of application of noise. - Abstract: We explore the diamagnetic susceptibility (DMS) of impurity doped quantum dot (QD) in presence of Gaussian white noise and under the combined influence of hydrostatic pressure (HP) and temperature (T). Presence of noise and also its mode of application discernibly affect the DMS profile. Application of HP and T invites greater delicacies in the observed DMS profiles. However, whereas the interplay between T and noise comes out to be extremely sensitive in fabricating the DMS profile, the pressure-noise interplay appears to be not that much noticeable. Under all conditions of temperature and pressure, the presence of multiplicative noise diminishes the value of DMS in comparison with that in presence of its additive analogue. The present study renders a deep insight into the remarkable role played by the interplay between noise, hydrostatic pressure and temperature in controlling the effective confinement imposed on the system which bears unquestionable relevance.

  14. Influence of Cu doping in borosilicate bioactive glass and the properties of its derived scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hui [School of Materials Science and Engineering, Tongji University, Shanghai 2001804 (China); Zhao, Shichang [Department of Orthopedic Surgery, Shanghai Sixth People' s Hospital, Shanghai Jiao Tong University, Shanghai 200233 (China); Xiao, Wei [Department of Materials Science and Engineering, and Center for Biomedical Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409-0340 (United States); Xue, Jingzhe [Department of Chemistry, Tongji University, Shanghai 200092 (China); Shen, Youqu [Department of Materials Science and Engineering, and Center for Biomedical Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409-0340 (United States); Zhou, Jie; Huang, Wenhai [School of Materials Science and Engineering, Tongji University, Shanghai 2001804 (China); Rahaman, Mohamed N. [Department of Materials Science and Engineering, and Center for Biomedical Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409-0340 (United States); Zhang, Changqing, E-mail: shzhangchangqing@163.com [Department of Orthopedic Surgery, Shanghai Sixth People' s Hospital, Shanghai Jiao Tong University, Shanghai 200233 (China); Wang, Deping, E-mail: wdpshk@tongji.edu.cn [School of Materials Science and Engineering, Tongji University, Shanghai 2001804 (China)

    2016-01-01

    Copper doped borosilicate glasses (BG–Cu) were studied by means of FT-IR, Raman, UV–vis and NMR spectroscopies to investigate the changes that appeared in the structure of borosilicate glass matrix by doping copper ions. Micro-fil and immunohistochemistry analysis were applied to study the angiogenesis of its derived scaffolds in vivo. Results indicated that the Cu ions significantly increased the B–O bond of BO{sub 4} groups at 980 cm{sup −1}, while they decrease that of BO{sub 2}O{sup −} groups at 1440–1470 cm{sup −1} as shown by Raman spectra. A negative shift was observed from {sup 11}B and {sup 29}Si NMR spectra. The {sup 11}B NMR spectra exhibited a clear transformation from BO{sub 3} into BO{sub 4} groups, caused by the agglutination effect of the Cu ions and the charge balance of the agglomerate in the glass network, leading to a more stable glass network and lower ions release rate in the degradation process. Furthermore, the BG–Cu scaffolds significantly enhanced blood vessel formation in rat calvarial defects at 8 weeks post-implantation. Generally, it suggested that the introduction of Cu into borosilicate glass endowed glass and its derived scaffolds with good properties, and the cooperation of Cu with bioactive glass may pave a new way for tissue engineering. - Highlights: • Agglutination effect of Cu{sup 2+} and charge balance of agglomerate lead to more stable glass. • Lower degradability and lower ions release were found in BG-Cu scaffolds. • Excellent angiogenesis and sustain Cu{sup 2+} release were endowed by doping Cu.

  15. Extent of pyrolysis impacts on fast pyrolysis biochar properties.

    Science.gov (United States)

    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. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  16. SnO2 thin-films prepared by a spray-gel pyrolysis: Influence of sol properties on film morphologies

    International Nuclear Information System (INIS)

    Luyo, Clemente; Fabregas, Ismael; Reyes, L.; Solis, Jose L.; Rodriguez, Juan; Estrada, Walter; Candal, Roberto J.

    2007-01-01

    Nanostructured tin oxide films were prepared by depositing different sols using the so-called spray-gel pyrolysis process. SnO 2 suspensions (sols) were obtained from tin (IV) tert-amyloxide (Sn(t-OAm) 4 ) or tin (IV) chloride pentahydrate (SnCl 4 .5H 2 O) precursors, and stabilized with ammonia or tetraethylammonium hydroxide (TEA-OH). Xerogels from the different sols were obtained by solvent evaporation under controlled humidity. The Relative Gelling Volumes (RGV) of these sols strongly depended on the type of precursor. Xerogels obtained from inorganic salts gelled faster, while, as determined by thermal gravimetric analysis, occluding a significant amount of volatile compounds. Infrared spectroscopic analysis was performed on raw and annealed xerogels (300, 500 deg. C, 1 h). Annealing removed water and ammonium or alkyl ammonium chloride, increasing the number of Sn-O-Sn bonds. SnO 2 films were prepared by spraying the sols for 60 min onto glass and alumina substrates at 130 deg. C. The films obtained from all the sols were amorphous or displayed a very small grain size, and crystallized after annealing at 400 deg. C or 500 deg. C in air for 2 h. X-ray diffraction analysis showed the presence of the cassiterite structure and line broadening indicated a polycrystalline material with a grain size in the nanometer range. Results obtained from Scanning Electron Microscopy analysis demonstrated a strong dependence of the film morphology on the RGV of the sols. Films obtained from Sn(t-OAm) 4 showed a highly textured morphology based on fiber-shape bridges, whereas the films obtained from SnCl 4 .5H 2 O had a smoother surface formed by 'O-ring' shaped domains. Lastly, the performance of these films as gas sensor devices was tested. The conductance (sensor) response for ethanol as a target analyte was of the same order of magnitude for the three kinds of films. However, the response of the highly textured films was more stable with shorter response times

  17. Thermodynamic analysis for syngas production from volatiles released in waste tire pyrolysis

    International Nuclear Information System (INIS)

    Martínez, Juan Daniel; Murillo, Ramón; García, Tomás; Arauzo, Inmaculada

    2014-01-01

    Highlights: • Pyrolysis experiments have been conducted in a continuous auger reactor. • Pyrolysis temperature influence on composition of both volatiles and char was studied. • A process for syngas production has been proposed from the volatiles. • Equivalence ratio down to 0.4 is a practical limit for syngas production. • The results provide essential data prior to perform any experimental campaign. - Abstract: This paper shows the maximum limit on syngas composition obtained from volatiles released in waste tire pyrolysis when they are submitted to an air–steam partial oxidation process. Thus, from mass and energy balances and a stoichiometric equilibrium model, syngas composition and reaction temperature as well as some process parameters were predicted by varying both the equivalence ratio (ER) and the steam to fuel ratio (SF). In addition, pyrolysis experiments were performed using a continuous auger reactor, and the influence of pyrolysis temperature on composition of both volatiles and char was studied. Consequently, the resulting syngas characteristics were correlated with the pyrolysis temperature. The stoichiometric equilibrium model showed that an ER down to 0.4 is a practical limit to perform the air–steam partial oxidation process. When the process is carried out only with air, volatiles obtained at high pyrolysis temperature lead to lower reaction temperature and higher LHV of syngas in comparison with those found at low pyrolysis temperature. The H 2 production is favored between 0.20 and 0.40 of ER and seems to be more influenced by the H/C ratio than by the water gas-shift reaction. On the other hand, the steam addition shows a more notable effect on the H 2 production for volatiles obtained at the highest pyrolysis temperature (600 °C) in agreement with the lower reaction temperature under these experimental conditions. This thermodynamic analysis provides essential data on the optimization of syngas production from volatiles

  18. Influence of tellurite on lifetime for samarium doped lanthanum lead borate glass

    Science.gov (United States)

    Madhu, A.; Eraiah, B.

    2018-04-01

    Samarium substituted tellurium lanthanum lead borate glass is prepared using melt quenching technique. Luminescence spectra have been recorded upon excitation with 402 nm various transitions from 4G5/2 level, for samarium doped tellurite glasses are studied and also lifetime for all the samples exhibit single exponential behaviour of decay curve. Luminescence spectra of present glasses show quenching effect due to cross-relation channels of samarium ions. The lifetime of glass samples decrease as the tellurite concentration is decreased. So, it evidences that to attain longer lifetime for lasing material one can tune the host by selecting concentration of tellurite.

  19. Conductivity of boron-doped polycrystalline diamond films: influence of specific boron defects

    Czech Academy of Sciences Publication Activity Database

    Ashcheulov, Petr; Šebera, Jakub; Kovalenko, Alexander; Petrák, Václav; Fendrych, František; Nesládek, M.; Taylor, Andrew; Vlčková Živcová, Zuzana; Frank, Otakar; Kavan, Ladislav; Dračínský, Martin; Hubík, Pavel; Vacík, Jiří; Kraus, I.; Kratochvílová, Irena

    2013-01-01

    Roč. 86, č. 10 (2013), , "443-1"-"443-9" ISSN 1434-6028 R&D Projects: GA TA ČR TA01011165; GA ČR(CZ) GAP304/10/1951; GA MŠk(XE) LM2011019; GA ČR GA13-31783S; GA MŠk(CZ) LD11076 EU Projects: European Commission(XE) 238201 - MATCON Institutional support: RVO:68378271 ; RVO:61388955 ; RVO:61388963 ; RVO:61389005 Keywords : polycrystalline diamond layer * conductivity B doping Subject RIV: BM - Solid Matter Physics ; Magnetism; CG - Electrochemistry (UFCH-W) Impact factor: 1.463, year: 2013

  20. Influence of Al doping on optical properties of CdS/PVA nanocomposites: Theory and experiment

    Energy Technology Data Exchange (ETDEWEB)

    Bala, Vaneeta, E-mail: vaneetabala@yahoo.com; Tripathi, S. K., E-mail: vaneetabala@yahoo.com; Kumar, Ranjan, E-mail: vaneetabala@yahoo.com [Department of Physics, Panjab University, Chandigarh (India)

    2014-04-24

    In the present work theoretical and experimental studies of aluminium doped cadmium sulphide polyvinyl alcohol (Al:CdS/PVA) nanocomposites have been carried out. Tetrahedral cluster AlCd{sub 9}S{sub 2}(SH){sub 18}]{sup 1−} has been encapsulated by small segments of polyvinyl alcohol (PVA) chains in order to simulate experimental environment of nanocomposites. Density functional theory (DFT) using local density approximation (LDA) functionals is employed to study the broadening of band gap upon ligation of nanoclusters. We have used in situ chemical route to synthesize nanocomposites. Optical band gap has been calculated from both experimental and theoretical approach.

  1. Influence of Na doping on the magnetic relaxation processes of magnetite

    International Nuclear Information System (INIS)

    Torres, C.; Arias, A. Gonzalez; Hisatake, K.; Francisco, C. de; Hernandez-Gomez, P.; Kim, C.O.; Kim, D.J.

    2007-01-01

    The relaxation of the initial magnetic permeability was measured in polycrystalline Na-doped magnetite samples, with nominal composition Na x Fe 3- x O 4 (x ranging from 0 to 0.05), by means of the magnetic disaccommodation (DA) technique. We found that the increasing amount of Na ions modifies the DA spectra and a very different behaviour depending on the sintering atmosphere. These results were discussed in terms of the presence of Na ions in the magnetite lattice, giving rise to certain modifications in their neighbourhood

  2. Release of Chlorine and Sulfur during Biomass Torrefaction and Pyrolysis

    DEFF Research Database (Denmark)

    Saleh, Suriyati Binti; Flensborg, Julie Pauline; Shoulaifar, Tooran Khazraie

    2014-01-01

    The release of chlorine (Cl) and sulfur (S) during biomass torrefaction and pyrolysis has been investigated via experiments in two laboratory-scale reactors: a rotating reactor and a fixed bed reactor. Six biomasses with different chemical compositions covering a wide range of ash content and ash...... reporting that biomasses with a lower chlorine content release a higher fraction of chlorine during the pyrolysis process. A significant sulfur release (about 60%) was observed from the six biomasses investigated at 350 degrees C. The initial sulfur content in the biomass did not influence the fraction...

  3. Influence of La content on magnetic properties of Cu doped M-type strontium hexaferrite: Structural, magnetic, and Mossbauer spectroscopy study

    Science.gov (United States)

    Ghimire, M.; Yoon, S.; Wang, L.; Neupane, D.; Alam, J.; Mishra, S. R.

    2018-05-01

    The present study investigates the influence of Cu2+ and La3+-Cu2+ doping on the magnetic properties of Sr1-xLaxFe12-xCuxO19 (x = 0.0-0.5) hexaferrite (SrM) compounds. The samples were prepared via facile autocombustion technique followed by sintering. X-ray powder diffraction patterns show the formation of the pure phase of M-type hexaferrite for all x. Invariance in lattice parameters was observed with only Cu2+ substitution while lattice contraction along c-axis was observed with co-doping La3+-Cu2+ in SrM. The magnetic property of these compounds is explained based on Cu2+ occupancy in the absence and presence of La3+ in SrM magnetoplumbite structure. The Cu2+ doped SrFe12-xCuxO19 sample showed a monotonic decrease in Ms value while La3+-Cu2+ showed a noticeable increase in Ms value with x. Furthermore, while coercivity of Cu2+ doped SrM reduced with x, the coercivity of La3+-Cu2+ doped SrM showed a marked 12% increase in coercivity at x = 0.1 (Hc = 4391 Oe) from that of x = 0.0 (3918 Oe). Interestingly, Cu2+ doped SrM displayed invariance in Tc ∼ 458.6 °C with x, while La3+-Cu2+ doping reduced Tc by 5% from its x = 0 (Tc = 451.9 °C) to 429.6 °C. The room temperature Mossbauer spectral analysis confirmed a Cu2+ preference for the 12k site and its occupancy is observed to be influenced by the presence of La3+ ion at the Sr2+ site.

  4. Self-activation of biochar from furfural residues by recycled pyrolysis gas.

    Science.gov (United States)

    Yin, Yulei; Gao, Yuan; Li, Aimin

    2018-04-17

    Biochar samples with controllable specific surface area and mesopore ratio were self-activated from furfural residues by recycled pyrolysis gas. The objective of this study was to develop a new cyclic utilization method for the gas produced by pyrolysis. The influences of preparation parameters on the resulting biochar were studied by varying the pyrolysis-gas flow rate, activation time and temperature. Structural characterization of the produced biochar was performed by analysis of nitrogen adsorption isotherms at 77 K and scanning electron microscope (SEM). The pyrolysis gas compositions before and after activation were determined by a gas chromatograph. The results indicated that the surface area of the biochar was increased from 167 m 2 /g to 567 m 2 /g, the total pore volume increased from 0.121 cm 3 /g to 0.380 cm 3 /g, and the ratio of the mesopore pore volume to the total pore volume increased 17-39.7%. The CO volume fraction of the pyrolysis gas changed from 34.66 to 62.29% and the CO 2 volume fraction decreased from 48.26% to 12.17% under different conditions of pyrolysis-gas flow rate, activation time and temperature. The calorific values of pyrolysis gas changed from 8.82 J/cm 3 to 14.00 J/cm 3 , which were higher than those of conventional pyrolysis gases. The slower pyrolysis-gas flow rate and higher activation time increased the efficiency of the reaction between carbon and pyrolysis gas. These results demonstrated the feasibility of treatment of the furfural residues to produce microporous and mesoporous biochar. The pyrolysis gas that results from the activation process could be used as fuel. Overall, this new self-activation method meets the development requirements of cyclic economy and cleaner production. Copyright © 2018. Published by Elsevier Ltd.

  5. Fast pyrolysis of hardwood residues using a fixed bed drop-type pyrolyzer

    International Nuclear Information System (INIS)

    Mazlan, Mohammad Amir Firdaus; Uemura, Yoshimitsu; Osman, Noridah B.; Yusup, Suzana

    2015-01-01

    Highlights: • Pyrolysis of rubber and Meranti wood was conducted by using a drop-type pyrolyzer. • As temperature increase, char yield decrease, but bio-oil and gas yield increase. • Maximum pyrolysis temperature for pyrolysis of RWS is 550 °C and 600 °C for MWS. • Calorific value of bio-char is very high and potential to be used as a solid fuel. • CO and CO 2 are the major gas components in the non-condensable gases by-product. - Abstract: In this research, rubber wood sawdust (RWS) and Meranti wood sawdust (MWS) were pyrolyzed in a fixed bed drop-type pyrolyzer under an inert condition. The first part of the study is to determine the influence of pyrolysis temperature (450, 500, 550, 600, 650 °C) on the yield of pyrolysis products. Pyrolysis of these different residues generate an almost identical maximum amount of bio-oil close to 33 wt.%, but at different maximum temperature (550 °C for pyrolysis of RWS and 600 °C for pyrolysis of MWS). To evaluate the effect of biomass type on the composition and characterization of pyrolysis products, the second part involves the analyses of pyrolysis products from the maximum pyrolysis temperature. Acetic acid, tetrahydrofuran, and benzene were the main bio-oil components. The bio-oil contained high percentage of oxygen and hydrogen, indicating high water content in the bio-oil. High amount of water in bio-oil significantly reduced its calorific value. Under extensive heating, particle size of the bio-char from SEM images decreased due to breakage and shrinkage mechanisms. The major components of non-condensable gases were CO and CO 2

  6. Performance of rotary kiln reactor for the elephant grass pyrolysis.

    Science.gov (United States)

    De Conto, D; Silvestre, W P; Baldasso, C; Godinho, M

    2016-10-01

    The influence of process conditions (rotary speed/temperature) on the performance of a rotary kiln reactor for non-catalytic pyrolysis of a perennial grass (elephant grass) was investigated. The product yields, the production of non-condensable gases as well as the biochar properties were evaluated. The maximum H2 yield was close to that observed for catalytic pyrolysis processes, while the bio-oil yield was higher than reported for pyrolysis of other biomass in rotary kiln reactors. A H2/CO ratio suitable for Fischer-Tropsch synthesis (FTS) was obtained. The biochars presented an alkaline pH (above 10) and interesting contents of nutrients, as well as low electrical conductivity, indicating a high potential as soil amendment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Influence of temperature on the photodegradation process using Ag-doped TiO2 nanostructures: Negative impact with the nanofibers

    DEFF Research Database (Denmark)

    Barakata, Nasser A.M.; Kanjwal, Muzafar Ahmed; Chronakis, Ioannis S.

    2013-01-01

    In this study, the influence of the temperature on the photodegradation process using Ag-doped TiO2 nanostructures was investigated. Two morphologies were used; nanoparticles and nanofibers. The nanofibers were synthesized by electrospinning of a sol–gel consisting of titanium isopropoxide, silve...

  8. Influence of metal doping of a MOF-74 framework on hydrogen adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Botas, J.A.; Calleja, G.; Orcajo, M.G. [Rey Juan Carlos Univ., Madrid (Spain). Dept. of Chemical and Energy Technology; Sanchez-Sanchez, M. [CSIC, Madrid (Spain). Inst. de Catalisis y Petroleoquimica

    2010-07-01

    Microporous Metal-Organic Framework (MOF) adsorbents are considered an interesting option for hydrogen storage. Due to their porous nature and unusually high surface areas, these materials show an exceptional H{sub 2} uptake. Unfortunately, their interaction with H{sub 2} molecules is weak, so cryogenic temperatures are required to reach competitive H{sub 2} storage capacities. In this sense, the presence of coordinatively unsaturated and exposed metal centers in some MOF frameworks could increase the affinity for H{sub 2} through stronger metal-H{sub 2} interactions. In this preliminary work, the effect of doping a Zn{sup 2+}-MOF-74 framework with Co{sup 2+}, Cu{sup 2+} and Mg{sup 2+} on its adsorption properties for H{sub 2} has been studied. Characterization studies suggest that the samples prepared have actually the MOF-74 structure, in which the different tested heteroatom ions have been successfully incorporated. The differences in H{sub 2} adsorption at 77 K and 87 K between the MOF-74 samples doped with the mentioned divalent metal ions were discussed as a function of their free pore volume and amount of metal incorporation. (orig.)

  9. Influence of vanadium doping on the electrochemical performance of nickel oxide in supercapacitors.

    Science.gov (United States)

    Park, Hae Woong; Na, Byung-Ki; Cho, Byung Won; Park, Sun-Min; Roh, Kwang Chul

    2013-10-28

    In this study, V-doped NiO materials were prepared by simple coprecipitation and thermal decomposition, and the effect of the vanadium content on the morphology, structural properties, electrochemical behavior, and cycling stability of NiO upon oxidation and reduction was analyzed for supercapacitor applications. The results show an improvement in the capacitive characteristics of the V-doped NiO, including increases in the specific capacitance after the addition of just 1.0, 2.0, and 4.0 at% V. All VxNi1-xO electrodes (x = 0.01, 0.02, 0.04) exhibited higher specific capacitances of 371.2, 365.7, and 386.2 F g(-1) than that of pure NiO (303.2 F g(-1)) at a current density of 2 A g(-1) after 500 cycles, respectively. The V0.01Ni0.99O electrode showed good capacitance retention of 73.5% at a current density of 2 A g(-1) for more than 500 cycles in a cycling test. Importantly, the rate capability of the V0.01Ni0.99O electrode was maintained at about 84.7% as discharge current density was increased from 0.5 A g(-1) to 4 A g(-1).

  10. Influence of cobalt doping on structural and magnetic properties of BiFeO3 nanoparticles

    Science.gov (United States)

    Khan, U.; Adeela, N.; Javed, K.; Riaz, S.; Ali, H.; Iqbal, M.; Han, X. F.; Naseem, S.

    2015-11-01

    Nanocrystalline cobalt-doped bismuth ferrites with general formula of BiFe1- δ Co δ O3 (0 ≤ δ ≤ 0.1) have been synthesized using solution evaporation method. Structure and phase identification was performed with X-ray diffraction (XRD) technique. The results confirm the formation of rhombohedral-distorted Perovskite structure with R3c symmetry. A decrease in lattice parameters and an increase in X-ray density have been observed with increasing cobalt concentration in BiFeO3. Particle size determined by transmission electron microscope was in good agreement with XRD, i.e., 39 nm. Room-temperature coercivity and saturation magnetization of nanoparticles were increased up to 7.5 % of cobalt doping. Low-temperature magnetic measurements of selected sample showed increasing behavior in saturation magnetization, coercivity, effective magnetic moments, and anisotropy constant. An increase in coercivity with decrease in temperature followed theoretical model of Kneller's law, while modified Bloch's model was employed for saturation magnetization in temperature range of 5-300 K.

  11. Influence of nitrogen doping in sumanene framework toward hydrogen storage: A computational study.

    Science.gov (United States)

    Reisi-Vanani, Adel; Shamsali, Fatemeh

    2017-09-01

    Two conditions are important to obtain appropriate substances for hydrogen storage; high surface area and fitting binding energy (BE). Doping is a key strategy that improves BE. We investigated hydrogen adsorption onto twenty six nitrogen disubstituted isomers of sumanene (C 19 N 2 H 12 ) by MP2/6-311++G(d,p)//B3LYP/6-31+G(d) and M06-2X/6-31+G(d) levels of theory. Effect of nitrogen doping in different positions of sumanene was checked. To obtain better BE, basis set superposition error (BSSE) and zero point energy (ZPE) corrections were used. Anticipating of adsorption sites and extra details about adsorption process was done by molecular electrostatic potential (MEP) surfaces. Various types of density of state (DOS) diagrams such as total DOS (TDOS), projected DOS (PDOS) and overlap population DOS (OPDOS) and natural bond orbital (NBO) analysis were used to find better insight on the adsorption properties. In addition of temperature depending of the BE, HOMO-LUMO gap (HLG), dipole moment, reactivity and stability, bowl depth and natural population analysis (NPA) of the isomers were studied. A physisorption mechanism for adsorption was proposed and a trivial change was seen. Place of nitrogen atoms in sumanene frame causes to binding energy increases or decreases compared with pristine sumanene. The best and the worst isomers and category of isomers were suggested. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Influence of Cu doping in borosilicate bioactive glass and the properties of its derived scaffolds.

    Science.gov (United States)

    Wang, Hui; Zhao, Shichang; Xiao, Wei; Xue, Jingzhe; Shen, Youqu; Zhou, Jie; Huang, Wenhai; Rahaman, Mohamed N; Zhang, Changqing; Wang, Deping

    2016-01-01

    Copper doped borosilicate glasses (BG-Cu) were studied by means of FT-IR, Raman, UV-vis and NMR spectroscopies to investigate the changes that appeared in the structure of borosilicate glass matrix by doping copper ions. Micro-fil and immunohistochemistry analysis were applied to study the angiogenesis of its derived scaffolds in vivo. Results indicated that the Cu ions significantly increased the B-O bond of BO4 groups at 980 cm(-1), while they decrease that of BO2O(-) groups at 1440-1470 cm(-1) as shown by Raman spectra. A negative shift was observed from (11)B and (29)Si NMR spectra. The (11)B NMR spectra exhibited a clear transformation from BO3 into BO4 groups, caused by the agglutination effect of the Cu ions and the charge balance of the agglomerate in the glass network, leading to a more stable glass network and lower ions release rate in the degradation process. Furthermore, the BG-Cu scaffolds significantly enhanced blood vessel formation in rat calvarial defects at 8 weeks post-implantation. Generally, it suggested that the introduction of Cu into borosilicate glass endowed glass and its derived scaffolds with good properties, and the cooperation of Cu with bioactive glass may pave a new way for tissue engineering. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Influence of deposition time on the surface morphology and photoelectrochemical properties of copper doped titania nanotubes prepared by electrodeposition

    Science.gov (United States)

    Mahmud, M. A.; Chin, L. Y.; Khusaimi, Z.; Zainal, Z.

    2018-05-01

    A great attention has focused on Cu doped titania nanotubes (Cu/TiNT) as a versatile advance material since it can be employed in various promising technological applications. The current study reported on the influence of various deposition times on the surface morphology and photoelectrochemical properties of Cu/TiNT via electrodeposition technique. Cu loaded on the TiNT surface was detected with prolonged deposition time. For photoelectrochemical (PEC) measurement, the highest responsive photocurrent density was obtained at 20 minutes with 54.3 µA/cm2. Too long duration (40 mins) resulted in poor performance of Cu/TiNT as only 22.6 µA/cm2 of photocurrent being generated.

  14. The influence of Co content on the luminescence properties of Co-doped ZnO nanoparticles

    Science.gov (United States)

    Guo, Shuxia; Jiang, Haitao

    2018-04-01

    Co-doped ZnO nanoparticles have been synthesized by co-precipitation technique. Photoluminescence spectra change in the range from 350 nm to 600 nm and remain unchanged at about 690 nm with the Co content increase. The UV emission is assigned to exciton emission. The density of band-edge states increases with Co content. The blue emission could be ascribed to the recombination of electrons in Co+ ions and holes in the valence band, whose relative intensity and full-width at half-maximum (FWHM) increase with the increase of cobalt concentration. The red emission results from the intra-d-shell emission at Co, which is independent of Co content. The relative density and energy-level position of green emission centers are also influenced by Co content.

  15. Influence of the sintering temperature on the structural and electronic properties of LaCrO3 doped with barium

    International Nuclear Information System (INIS)

    Silva, A.L.A. da; Souza, M.V.M.M.; Rocco, A.M.

    2010-01-01

    Ba-doped lanthanum chromites were synthesized by combustion method, utilizing urea and glycine as fuel agents. The powders were calcined (800 deg C/6 h), pelletized, sintered in various temperatures and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), density/porosity and electrical conductivity. The diffractograms of the sintered samples presented a well-defined structure, with presence of secondary phases which increase with the sintering temperature. The samples presented low densities and a high porosities (40 - 50%), which was also observed in SEM analysis. The urea-synthesized sample presented a higher conductivity (10.4 S/cm at 1000 deg C), which is related to the influence of the fuel agent in the material properties. (author)

  16. Influence of morphology and topography on potentiometric response of magnesium and calcium sensitive PEDOT films doped with adenosine triphosphate (ATP)

    International Nuclear Information System (INIS)

    Paczosa-Bator, B.; Peltonen, J.; Bobacka, J.; Lewenstam, A.

    2006-01-01

    Poly(3,4-ethylenedioxythiophene) (PEDOT) films doped with adenosine triphosphate (ATP) are used to study the biologically relevant competitive magnesium and calcium ion-exchange at ATP membrane sites. It is shown, by atomic force microscopy (AFM) and scanning electron microscopy (SEM), that the surface topography and morphology of the PEDOT-ATP films determines the quality of their potentiometric response. More smooth and less rough films result in better potentiometric characteristics, particularly in a faster response. The topography/morphology of the PEDOT-ATP films is influenced by conditions during electrodeposition (electrochemical method of deposition, pH, concentration of electrolytes) and post-deposition soaking (including net-time of soaking), as evidenced by X-ray photoelectron spectroscopy (XPS) and energy dispersive analysis of X-rays (EDAX)

  17. Sugarcane Bagasse Pyrolysis in a Carbon Dioxide Atmosphere with Conventional and Microwave-Assisted Heating

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Bo-Jhih; Chen, Wei-Hsin, E-mail: weihsinchen@gmail.com [Department of Aeronautics and Astronautics, National Cheng Kung University, Tainan, Taiwan (China)

    2015-02-04

    Pyrolysis is an important thermochemical method to convert biomass into bio-oil. In this study, the pyrolysis of sugarcane bagasse in a CO{sub 2} atmosphere under conventional and microwave-assisted heating is investigated to achieve CO{sub 2} utilization. In the microwave pyrolysis, charcoal is used as the microwave absorber to aid in pyrolysis reactions. The results indicate that the yields of pyrolysis products are greatly influenced by the heating modes. In the conventional heating, the prime product is bio-oil and its yield is in the range of 51–54 wt%, whereas biochar is the major product in microwave-assisted heating and its yield ranges from 61 to 84 wt%. Two different absorber blending ratios of 0.1 and 0.3 are considered in the microwave pyrolysis. The solid yield decreases when the absorber blending ratio decreases from 0.3 to 0.1, while the gas and liquid yields increase. This is attributed to more energy consumed for bagasse pyrolysis at the lower blending ratio. Hydrogen is produced under the microwave pyrolysis and its concentration is between 2 and 12 vol%. This arises from the fact that the secondary cracking of vapors and the secondary decomposition of biochar in an environment with microwave irradiation is easier than those with conventional heating.

  18. Fast Pyrolysis of Lignin Using a Pyrolysis Centrifuge Reactor

    DEFF Research Database (Denmark)

    Trinh, Ngoc Trung; Jensen, Peter Arendt; Sárossy, Zsuzsa

    2013-01-01

    Fast pyrolysis of lignin from an ethanol plant was investigated on a lab scale pyrolysis centrifuge reactor (PCR) with respect to pyrolysis temperature, reactor gas residence time, and feed rate. A maximal organic oil yield of 34 wt % dry basis (db) (bio-oil yield of 43 wt % db) is obtained...... at temperatures of 500−550 °C, reactor gas residence time of 0.8 s, and feed rate of 5.6 g/min. Gas chromatography mass spectrometry and size-exclusion chromatography were used to characterize the Chemical properties of the lignin oils. Acetic acid, levoglucosan, guaiacol, syringols, and p-vinylguaiacol are found...... components and molecular mass distribution of the lignin oils. The obtained lignin oil has a very different components composition when compared to a beech wood oil....

  19. Influence of γ-radiation on the D.C. conductivity of poly(3-hexadecylthiophene) doped with iron trichloride in an atmosphere of organic agents

    International Nuclear Information System (INIS)

    Cik, G.; Szabo, L.; Merasicky, J.

    1996-01-01

    The influence of γ-radiation on the d.c. conductivity of poly(3-hexadecylthiophene) (PHDT) doped with FeCl 3 in chloroform, toluene, ethanol and nitrobenzene atmospheres has been studied. A different course of d.c. conductivity changes taking place in the atmosphere of solvent vapors (chloroform, toluene) and precipitants (ethanol, nitrobenzene) has been found. The character of changes can be influenced by polymer cross-linking initiated by γ-radiation. (author). 8 refs., 5 figs

  20. Fuels Combustion Research: Supercritical Fuel Pyrolysis

    National Research Council Canada - National Science Library

    Glassman, Irvin

    2001-01-01

    .... The focus during the subject period was directed to understanding the pyrolysis and combustion of endothermic fuels under subcritical conditions and the pyrolysis of these fuels under supercritical conditions...

  1. Fuels Combustion Research: Supercritical Fuel Pyrolysis

    National Research Council Canada - National Science Library

    Glassman, Irvin

    2000-01-01

    .... The focus during the subject period was directed to understanding the pyrolysis and combustion of endothermic fuels under subcritical conditions and the pyrolysis of these fuels under supercritical conditions...

  2. Influence of fluorescence of Eu(dbm)3phen doped films by gold nanorods

    International Nuclear Information System (INIS)

    Wang, Qingru; Shi, Qiang; Li, Shuhong; Zhang, Dong; Wang, Wenjun

    2016-01-01

    The gold nanorods (AuNRs) were precipitated on Eu(dbm) 3 phen doped films by different spin rates. The plasmonic enhancement and quenching effects of gold nanorods on the fluorescence of Eu(dbm) 3 phen were both demonstrated. The enhancement on the fluorescence is sensitive to the distribution of the AuNRs. Both fluorescence enhancement mechanisms, i.e. increase of the intense absorption of ligands and increase of quantum efficiency, promote the 20 fold enhancement, at which the excitation wavelength red-shifts from 362 nm to 372 nm. Higher absorption of ligands in the complex due to the AuNRs caused the bathochromic shift of excitation peak. The quenching factor at 612 nm reached to 0.47.

  3. Influence of silver nanoparticles on the spectroscopic properties of Sm3+ doped boro-phosphate glasses

    Science.gov (United States)

    Suthanthirakumar, P.; Marimuthu, K.

    2016-05-01

    The Sm3+ doped novel boro-phosphate glasses containing silver nanoparticles (NPs) (SmBPxA) have been prepared following the melt quenching technique and their structural and spectroscopic behavior were studied through HR-TEM, optical absorption and photoluminescence spectral measurements. The TEM analysis validates the existence of Ag NPs with an average diameter of ~8 nm. The Surface plasmon resonance (SPR) band of silver NPs was found at around 600 nm from the absorption spectrum of the Sm3+ ions free glass sample. The optical band gap energy (Eopt) corresponding to the direct and indirect allowed transitions and the Urbach energy (ΔE) values were determined from the absorption spectral measurements. The luminescence intensity is found to get enhance when the Ag NPs were embedded along with the Sm3+ ions in the prepared glasses due to the local electric field effect around the rare earth (RE) ion site produced by the SPR of Ag NPs.

  4. Influence of Thermal Treatment on the Antimicrobial Activity of Silver-Doped Biological Apatite

    Science.gov (United States)

    Popa, Cristina Liana; Ciobanu, Carmen Steluta; Voicu, Georgeta; Vasile, Eugenia; Chifiriuc, Mariana Carmen; Iconaru, Simona Liliana; Predoi, Daniela

    2015-12-01

    In this paper, we report the structural and morphological properties of silver-doped hydroxyapatite (AgHAp) with a silver concentration x Ag = 0.5 before and after being thermal treated at 600 and 1000 °C. The results obtained by X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy suggest that the structure of the samples changes gradually, from hydroxyapatite (AgHAp_40) to a predominant β-TCP structure (AgHAp_1000), achieved when the thermal treatment temperature is 1000 °C. In the AgHAp_600 sample, the presence of two phases, HAp and β-TCP, was highlighted. Also, scanning electron microscopy studies suggest that the shape and dimension of the nanoparticles begin to change when the temperature increases. The antimicrobial activity of the obtained compounds was evaluated against Klebsiella pneumoniae, Staphylococcus aureus, and Candida albicans strains.

  5. Gadolinium doped cerium oxide for soot oxidation: Influence of interfacial metal–support interactions

    International Nuclear Information System (INIS)

    Durgasri, D. Naga; Vinodkumar, T.; Lin, Fangjian; Alxneit, Ivo; Reddy, Benjaram M.

    2014-01-01

    Graphical abstract: - Highlights: • Supported Ce-Gd-oxides are applied for soot oxidation for the first time. • Gd 2 O 3 doping facilitates enhanced extrinsic oxygen vacancy concentration in ceria. • The Ce-Gd/TiO 2 exhibited the highest soot oxidation activity. • Key parameters that involved in tuning the activity are discussed. - Abstract: The aim of the present investigation was to ascertain the role of Al 2 O 3 , SiO 2 , and TiO 2 supports in modulating the catalytic performance of ceria-based solid solutions. In this study, we prepared nanosized Ce-Gd/Al 2 O 3 , Ce-Gd/SiO 2 , and Ce-Gd/TiO 2 catalysts by a deposition coprecipitation method and evaluated for soot oxidation. The synthesized catalysts were calcined at two different temperatures to assess their thermal stability and extensively characterized by various techniques, namely, XRD, Raman, BET surface area, TEM, H 2 -TPR, and UV–vis DRS. XRD and TEM results indicate that Ce-Gd-oxide nanoparticles are in highly dispersed form on the surface of the supports. Raman results show a prominent sharp peak and a broad peak corresponding to the F 2g mode of ceria and the presence of oxygen vacancies, respectively. The presence of a significant number of oxygen vacancies in all samples is also confirmed from UV–vis DRS measurements. The H 2 -TPR results suggest that Gd-doping facilitates the reduction of the materials and decreases the onset temperature of reduction. Among the prepared samples, Ce-Gd/TiO 2 catalyst exhibited the highest activity, suggesting the existence of strong interfacial metal support interaction between the active metal oxide and the support

  6. Gadolinium doped cerium oxide for soot oxidation: Influence of interfacial metal–support interactions

    Energy Technology Data Exchange (ETDEWEB)

    Durgasri, D. Naga; Vinodkumar, T. [Inorganic and Physical Chemistry Division, CSIR–Indian Institute of Chemical Technology, Uppal Road, Hyderabad 500 007 (India); Lin, Fangjian; Alxneit, Ivo [Solar Technology Laboratory, Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland); Reddy, Benjaram M., E-mail: bmreddy@iict.res.in [Inorganic and Physical Chemistry Division, CSIR–Indian Institute of Chemical Technology, Uppal Road, Hyderabad 500 007 (India)

    2014-09-30

    Graphical abstract: - Highlights: • Supported Ce-Gd-oxides are applied for soot oxidation for the first time. • Gd{sub 2}O{sub 3} doping facilitates enhanced extrinsic oxygen vacancy concentration in ceria. • The Ce-Gd/TiO{sub 2} exhibited the highest soot oxidation activity. • Key parameters that involved in tuning the activity are discussed. - Abstract: The aim of the present investigation was to ascertain the role of Al{sub 2}O{sub 3}, SiO{sub 2}, and TiO{sub 2} supports in modulating the catalytic performance of ceria-based solid solutions. In this study, we prepared nanosized Ce-Gd/Al{sub 2}O{sub 3}, Ce-Gd/SiO{sub 2}, and Ce-Gd/TiO{sub 2} catalysts by a deposition coprecipitation method and evaluated for soot oxidation. The synthesized catalysts were calcined at two different temperatures to assess their thermal stability and extensively characterized by various techniques, namely, XRD, Raman, BET surface area, TEM, H{sub 2}-TPR, and UV–vis DRS. XRD and TEM results indicate that Ce-Gd-oxide nanoparticles are in highly dispersed form on the surface of the supports. Raman results show a prominent sharp peak and a broad peak corresponding to the F{sub 2g} mode of ceria and the presence of oxygen vacancies, respectively. The presence of a significant number of oxygen vacancies in all samples is also confirmed from UV–vis DRS measurements. The H{sub 2}-TPR results suggest that Gd-doping facilitates the reduction of the materials and decreases the onset temperature of reduction. Among the prepared samples, Ce-Gd/TiO{sub 2} catalyst exhibited the highest activity, suggesting the existence of strong interfacial metal support interaction between the active metal oxide and the support.

  7. Influence of γ- radiation on the recombination properties of P-type nickel doped silicon

    International Nuclear Information System (INIS)

    Kurbanov, A.O.; Karimov, M.

    2006-01-01

    Full text: It is well known that the life-time of the charge carriers is most sensitive parameter of the semiconductors. The results of numerous investigations show that by irradiation of the multi-crystal silicon with high-energy particles (electrons, protons, γ-quanta) the life-time of the minor charge carriers appreciably decreases. Ones think that the reason of such effect is the generation of the recombination radiation defects by irradiation. In this connection in this work the investigation of the nickel doped silicon with various post-diffusion cooling is performed. As an initial material the p - Si with ∼ 10 Ohm·cm specific resistance was used. The dislocation density is taken to be ∼10 4 cm -2 . Doping of silicon by nickel carried out in the temperature range of 1050-1150 degree C with succeeding I and II type cooling. The life-time of the charge carriers was determined using the stationary photoconductivity method. It is discovered that the life-time of the charge carriers in p-Si is longer than that in the control silicon as well as τ slightly increases by increasing of the nickel's atoms concentration (in these samples the acceptor centers concentration changes in the range of 1.5·10 14 - 3.5·10 14 cm -3 ). This effect is explained on a basis of investigations of the photoconductivity relaxation kinetics (at 70 K) by the capture of the charge carriers to the sticking level. It is revealed that the relative life-time changing is appreciably various one from other in I and II type samples. In the rapid cooled samples τ more stable than slow cooled samples. In the rapid cooled samples more stable than slow cooled samples up to doze ∼2.5·10 8 R. (author)

  8. Influence of Al doping on structural and optical properties of Mg–Al co-doped ZnO thin films prepared by sol–gel method

    International Nuclear Information System (INIS)

    Fang, Dongyu; Lin, Kui; Xue, Tao; Cui, Can; Chen, Xiaoping; Yao, Pei; Li, Huijun

    2014-01-01

    Highlights: • Mg–Al co-doped ZnO thin films were prepared by sol–gel spin coating method. • The effects of Al doping on structural and optical properties of AMZO thin films were investigated. • The EDS spectra confirmed presence of Mg and Al elements in AMZO thin films. • The optical band gap of AMZO thin films increased with Al doping concentration increased. • The origin of the photoluminescence emissions was discussed. -- Abstract: Mg–Al co-doped ZnO (AMZO) thin films were successfully deposited onto quartz glass substrates by sol–gel spin coating method. The structure, surface morphology, composition, optical transmittance, and photoluminescence properties of AMZO thin films were characterized through X-ray diffraction, scanning electron microscopy with energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy, UV–VIS–NIR spectrophotometry, and fluorescence spectrophotometry. The results indicated that AMZO thin films exhibited preferred orientation growth along the c-axis, and the full width at half maximum of the (0 0 2) diffraction peak decreased first and subsequently increased, reaching a minimum of approximately 0.275° at 3% Al content. The calculated crystallite size increased from 30.21 nm to 40.73 nm. Al doping content increased from 1% to 3% and subsequently reached 19.33 nm for Al doping content at 5%. The change in lattice parameters was demonstrated by the c/a ratio, residual stress, bond length, and volume per unit cell. EDS analysis confirmed the presence of Mg and Al elements in ZnO thin films. The atomic percentage of Mg and Al elements was nearly equal to their nominal stoichiometry within the experimental error. In addition, the optical transmittance of AMZO thin films was over 85% in the visible region, and the optical band gap increased with increasing Al doping concentration. Room temperature photoluminescence showed ultraviolet emission peak and defect emission peak. The defect emission peak of

  9. Pyrolysis of Coconut Shell: An Experimental Investigation

    Directory of Open Access Journals (Sweden)

    E. Ganapathy Sundaram

    2009-12-01

    Full Text Available Fixed-bed slow pyrolysis experiments of coconut shell have been conducted to determine the effect of pyrolysis temperature, heating rate and particle size on the pyrolysis product yields. The effect of vapour residence time on the pyrolysis yield was also investigated by varying the reactor length. Pyrolysis experiments were performed at pyrolysis temperature between 400 and 600°C with a constant heating rate of 60°C/min and particle sizes of 1.18-1.80 mm. The optimum process conditions for maximizing the liquid yield from the coconut shell pyrolysis in a fixed bed reactor were also identified. The highest liquid yield was obtained at a pyrolysis temperature of 550 °C, particle size of 1.18-1.80 mm, with a heating rate of 60 °C/min in a 200 mm length reactor. The yield of obtained char, liquid and gas was 22-31 wt%, 38-44 wt% and 30-33 wt% respectively at different pyrolysis conditions. The results indicate that the effects of pyrolysis temperature and particle size on the pyrolysis yield are more significant than that of heating rate and residence time. The various characteristics of pyrolysis oil obtained under the optimum conditions for maximum liquid yield were identified on the basis of standard test methods.

  10. Exploratory studies on fast pyrolysis oil upgrading

    NARCIS (Netherlands)

    Mahfud, Farchad Husein

    2007-01-01

    Pyrolysis oil is a dark brown liquid which can be produced in high yield from different kind of biomass sources by means of fast pyrolysis. Pyrolysis oil is considered as a promising second generation energy carrier and may play an important role in the future of "biobased economies". The energy

  11. Fractional condensation of biomass pyrolysis vapors

    NARCIS (Netherlands)

    Westerhof, Roel Johannes Maria; Brilman, Derk Willem Frederik; Garcia Perez, M.; Wang, Zhouhong; Oudenhoven, Stijn; van Swaaij, Willibrordus Petrus Maria; Kersten, Sascha R.A.

    2011-01-01

    In this paper, we have investigated the possibilities to steer the composition and, thus, the quality of pyrolysis liquids by the reactor temperature and the pyrolysis vapor condenser temperature. Pine wood was pyrolyzed in a 1 kg/h fluidized-bed pyrolysis reactor operated at 330 or 480 °C. The

  12. Influence of W content on tribological performance of W-doped diamond-like carbon coatings under dry friction and polyalpha olefin lubrication conditions

    International Nuclear Information System (INIS)

    Fu, Zhi-qiang; Wang, Cheng-biao; Zhang, Wei; Wang, Wei; Yue, Wen; Yu, Xiang; Peng, Zhi-jian; Lin, Song-sheng; Dai, Ming-jiang

    2013-01-01

    Highlights: • W-doped DLC coating with various W contents was fabricated. • Friction and wear of DLC coated sample was studied. • The lubricant additive was T307. • The influence of W content on friction under lubrication was unveiled. • The influence of W content on wear under lubrication was studied. - Abstract: The influence on tungsten content on the structure, mechanical properties and tribological performance of W-doped diamond-like carbon (DLC) coatings was studied by X-ray photoelectron spectroscopy, nano-indentation, scratch test, and ball-on-disk friction test. It was found that with increasing W content, the content of WC and free W in the coatings is increased while the content of sp 3 -C in the coatings is decreased. The effect of W content on the hardness and elastic modulus of the coatings is indistinctive, but there exists the highest critical load of scratch test of above 100 N when W content is 3.08 at.%. With the increase of W content, the friction coefficients of W-doped DLC coatings under dry friction conditions are increased while the friction coefficients of W-doped DLC coatings under polyalpha olefin (PAO) lubrication are decreased. With the increase of W content, the wear rates of the DLC-coated samples under dry friction conditions show a minimum value; under pure PAO lubrication, the influence of W content on the wear rates of the DLC-coated samples is indistinctive when the W content is below 10.73 at.% while the wear rates are increased with increasing W content from 10.73 at.% to 24.09 at.%; when lubricated by PAO + thiophosphoric acid amine (T307) salt, the samples coated with the undoped DLC or the W-doped DLC with high W content exhibit low wear rates

  13. Why don’t you Dope? A preliminary analysis of the factors which influence athletes decision not to Dope in Sport

    Directory of Open Access Journals (Sweden)

    Terri Byers

    2015-10-01

    Full Text Available The purpose of this paper is to examine why athletes do not dope in sport. The research treats the ‘problem’ of doping as an issue of ‘control’ and draws on control theory (Hopwood, 1974; Byers, 2013 to analyze athletes choices not to engage in doping. Semi-structured interviews were conducted with cur- rent Canadian athletes, former athletes, coaches, and officials from seven different sports that competed in the CIS (Canadian Interuniversity Sport, national and international events, professional sport, Pan American Games, provincial teams, and World University Games. In total, 20 interviews were conducted with 7 female and 13 male participants. Results indicate that an over- abundance of administrative formal control mechanisms may be creating confusion and inefficiency in the doping control system. More powerful control mechanisms such as social and self-controls seem to be operating amongst athletes and issues of trust and the role of emotion are significant concepts that re- quire further research in this context.

  14. Influences of Different Preparation Conditions on Catalytic Activity of Ag2O-Co3O4/γ-Al2O3 for Hydrogenation of Coal Pyrolysis

    Directory of Open Access Journals (Sweden)

    Lei Zhang

    2014-01-01

    Full Text Available A series of catalysts of Ag2O-Co3O4/γ-Al2O3 was prepared by equivalent volume impregnation method. The effects of the metal loading, calcination time, and calcination temperatures of Ag and Co, respectively, on the catalytic activity were investigated. The optimum preparing condition of Ag2O-Co3O4/γ-Al2O3 was decided, and then the influence of different preparation conditions on catalytic activity of Ag2O-Co3O4/γ-Al2O3 was analyzed. The results showed the following: (1 at the same preparation condition, when silver loading was 8%, the Ag2O-Co3O4/γ-Al2O3 showed higher catalyst activity, (2 the catalyst activity had obviously improved when the cobalt loading was 8%, while it was weaker at loadings 5% and 10%, (3 the catalyst activity was influenced by different calcination temperatures of silver, but the influences were not marked, (4 the catalyst activity can be influenced by calcination time of silver, (5 different calcination times of cobalt can also influence the catalyst activity of Ag2O-Co3O4/γ-Al2O3, and (6 the best preparation conditions of the Ag2O-Co3O4/γ-Al2O3 were silver loading of 8%, calcination temperature of silver of 450°C, and calcinations time of silver of 4 h, while at the same time the cobalt loading was 8%, the calcination temperature of cobalt was 450°C, and calcination time of cobalt was 4 h.

  15. Influence of n$^{+}$ and p$^{+}$ doping on the lattice sites of implanted Fe in Si

    CERN Document Server

    Silva, Daniel José; Correia, João Guilherme; Araújo, João Pedro

    2013-01-01

    We report on the lattice location of implanted $^{59}$Fe in n$^{+}$ and p$^{+}$ type Si by means of emission channeling. We found clear evidence that the preferred lattice location of Fe changes with the doping of the material. While in n$^{+}$ type Si Fe prefers displaced bond-centered (BC) sites for annealing temperatures up to 600°C, changing to ideal substitutional sites above 700°C, in p$^{+}$ type Si, Fe prefers to be in displaced tetrahedral interstitial positions after all annealing steps. The dominant lattice sites of Fe in n$^{+}$ type Si therefore seem to be well characterized for all annealing temperatures by the incorporation of Fe into vacancy-related complexes, either into single vacancies which leads to Fe on ideal substitutional sites, or multiple vacancies, which leads to its incorporation near BC sites. In contrast, in p$^{+}$ type Si, the major fraction of Fe is clearly interstitial (near-T or ideal T) for all annealing temperatures. The formation and possible lattice sites of Fe in FeB...

  16. Influences of Co doping on the structural and optical properties of ZnO nanostructured

    Science.gov (United States)

    Majeed Khan, M. A.; Wasi Khan, M.; Alhoshan, Mansour; Alsalhi, M. S.; Aldwayyan, A. S.

    2010-07-01

    Pure and Co-doped ZnO nanostructured samples have been synthesized by a chemical route. We have studied the structural and optical properties of the samples by using X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), field-emission transmission electron microscope (FETEM), energy-dispersive X-ray (EDX) analysis and UV-VIS spectroscopy. The XRD patterns show that all the samples are hexagonal wurtzite structures. Changes in crystallite size due to mechanical activation were also determined from X-ray measurements. These results were correlated with changes in particle size followed by SEM and TEM. The average crystallite sizes obtained from XRD were between 20 to 25 nm. The TEM images showed the average particle size of undoped ZnO nanostructure was about 20 nm whereas the smallest average grain size at 3% Co was about 15 nm. Optical parameters such as absorption coefficient ( α), energy band gap ( E g ), the refractive index ( n), and dielectric constants ( σ) have been determined using different methods.

  17. Electric field influence on exciton absorption of Er doped and undoped InSe single crystals

    International Nuclear Information System (INIS)

    Guerbulak, B; Kundakci, M; Ates, A; Yildirim, M

    2007-01-01

    Undoped InSe and Er doped InSe (InSe:Er) single crystals were grown by using the Stockbarger method. Ingots had no cracks and voids on the surface. The absorption measurements were carried out in InSe and InSe:Er samples for U=0 and U=30 V in the temperature range 10-320 K with a step of 10 K. Electric field effects on excitons are observed in InSe and InSe:Er single crystals. The absorption edge shifted towards longer wavelengths and decreased intensity in absorption spectra under an electric field E≅5.9 kV cm -1 . The applied electric field caused a shifting and a decreasing of intensity in the absorption spectra. The shifting of the absorption edge can be explained on the basis of the Franz-Keldysh effect (FKE) or thermal heating of the sample under the electric field. At 10 and 320 K, the first exciton energies for InSe were calculated as 1.336 and 1.291 eV for zero voltage and 1.331 and 1.280 eV for electric field and InSe:Er as 1.329 and 1.251 eV for zero voltage and 1.318 and 1.248 eV for electric field, respectively

  18. Influence of milling and calcination steps on phase assemblage of strontium and magnesium doped lanthanum gallate

    International Nuclear Information System (INIS)

    Reis, S.L.; Muccillo, E.N.S.

    2011-01-01

    Sr- and Mg- doped lanthanum gallate (La_1_-_xSr_xGa_1_-_yMg_yO_3_δ) is one of the most promising solid electrolyte and electrode components for solid oxide fuel cells operating at low-temperature, due to its high electric conductivity and stability over a wide range of oxygen partial pressures. In this work, La_0_,_9Sr_0_,_1Ga_0_,_8Mg_0_,_2O_2_,_85 was prepared by different solid state reaction routes. The main purpose is to determine a suitable processing route that enables high sintering density along with free or negligible secondary phase contents. Phase analysis was carried out by X-ray diffraction and the sintered density was obtained from the water immersion method. Results on X-ray diffraction showed negligible secondary phases formed even for sintering at relatively high temperatures. The apparent density obtained was higher than 95% of the theoretical value for all routes. The main difference observed among the studied routes is the final contents of secondary phases. (author)

  19. p-type doping efficiency in CdTe: Influence of second phase formation

    Science.gov (United States)

    McCoy, Jedidiah J.; Swain, Santosh K.; Sieber, John R.; Diercks, David R.; Gorman, Brian P.; Lynn, Kelvin G.

    2018-04-01

    Cadmium telluride (CdTe) high purity, bulk, crystal ingots doped with phosphorus were grown by the vertical Bridgman melt growth technique to understand and improve dopant solubility and activation. Large net carrier densities have been reproducibly obtained from as-grown ingots, indicating successful incorporation of dopants into the lattice. However, net carrier density values are orders of magnitude lower than the solubility of P in CdTe as reported in literature, 1018/cm3 to 1019/cm3 [J. H. Greenberg, J. Cryst. Growth 161, 1-11 (1996) and R. B. Hall and H. H. Woodbury, J. Appl. Phys. 39(12), 5361-5365 (1968)], despite comparable starting charge dopant densities. Growth conditions, such as melt stoichiometry and post growth cooling, are shown to have significant impacts on dopant solubility. This study demonstrates that a significant portion of the dopant becomes incorporated into second phase defects as compounds of cadmium and phosphorous, such as cadmium phosphide, which inhibits dopant incorporation into the lattice and limits maximum attainable net carrier density in bulk crystals. Here, we present an extensive study on the characteristics of these second phase defects in relation to their composition and formation kinetics while providing a pathway to minimize their formation and enhance solubility.

  20. Doping β-Ga2O3 with europium: influence of the implantation and annealing temperature

    Science.gov (United States)

    Peres, M.; Lorenz, K.; Alves, E.; Nogales, E.; Méndez, B.; Biquard, X.; Daudin, B.; Víllora, E. G.; Shimamura, K.

    2017-08-01

    β-Ga2O3 bulk single crystals were doped by ion implantation at temperatures from room temperature to 1000 °C, using a 300 keV Europium beam with a fluence of 1  ×  1015 at cm-2. Rising the implantation temperature from room temperature to 400-600 °C resulted in a significant increase of the substitutional Eu fraction and of the number of Eu ions in the 3+  charge state as well as in a considerable decrease of implantation damage. Eu is found in both charge states 2+  and 3+  and their relative fractions are critically dependent on the implantation and annealing temperature, suggesting that defects play an important role in stabilizing one of the charge states. The damage recovery during post-implant annealing is a complex process and typically defect levels first increase for intermediate annealing temperatures and a significant recovery of the crystal only starts around 1000 °C. Cathodoluminescence spectra are dominated by the sharp Eu3+ related intra-ionic 4f transition lines in the red spectral region. They show a strong increase of the emission intensity with increasing annealing temperature, in particular for samples implanted at elevated temperature, indicating the optical activation of Eu3+ ions. However, no direct correlation of emission intensity and Eu3+ fraction was found, again pointing to the important role of defects on the physical properties of these luminescent materials.

  1. Oxygen influence on luminescence properties of rare-earth doped NaLaF{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Tuomela, A., E-mail: anu.tuomela@oulu.fi [Research Center of Molecular Materials, University of Oulu, P.O. Box 3000, FIN-90014 (Finland); Pankratov, V., E-mail: vladimirs.pankratovs@oulu.fi [Research Center of Molecular Materials, University of Oulu, P.O. Box 3000, FIN-90014 (Finland); Sarakovskis, A.; Doke, G.; Grinberga, L. [Institute of Solid State Physics, University of Latvia, 8 Kengaraga, LV-1063 Riga (Latvia); Vielhauer, S. [Institute of Physics, University of Tartu, Riia 142, Tartu 51014 (Estonia); Huttula, M. [Research Center of Molecular Materials, University of Oulu, P.O. Box 3000, FIN-90014 (Finland)

    2016-11-15

    Luminescence properties of erbium and europium doped NaLaF{sub 4} with different oxygen content have been studied. Vacuum ultraviolet (VUV) excitation luminescence spectroscopy technique has been applied by using synchrotron radiation excitation. It was found that oxygen impurity leads to significant degradation of Er{sup 3+} or Eu{sup 3+} emission under VUV excitation. The intensive O{sup 2−}–Er{sup 3+} charge transfer excitation band has been detected from oxygen abundant NaLaF{sub 4} in the 150–165 nm spectral range. This band reveals a competing absorption mechanism in oxygen containing NaLaF{sub 4}. It is clearly demonstrated that one reason for the Er{sup 3+} emission degradation in oxygen abundant NaLaF{sub 4} is strong suppression of 4f–5d transitions in Er{sup 3+} ion. The degradation of the Eu{sup 3+} emission under VUV excitation was explained by diminishing of F{sup −}–Eu{sup 3+} charge transfer absorption band as well as by competing relaxation centers in the oxygen abundant NaLaF{sub 4}.

  2. The role of palladium in iron based Fischer-Tropsch catalysts prepared by flame spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Minnermann, M.; Zielasek, V.; Baeumer, M. [Bremen Univ. (DE). Inst. of Applied and Physical Chemistry (IAPC); Pokhrei, S.; Maedler, L. [Bremen Univ. (DE). Foundation Inst. of Materials Science (IWT); Thiel, K. [Fraunhofer Institute for Manufactoring Technology and Applied Materials Research, Bremen (Germany)

    2011-07-01

    Flame spray pyrolysis (FSP) is a novel technique for the fabrication of nanostructured catalysts with far-reaching options to control structure and composition even in cases where complex composites need to be prepared. In this study, we took advantage of this technique to synthesize highly dispersed pure and Pd-doped iron oxide nanoparticles and investigated them as Fischer-Tropsch (FT) catalysts. By systematically varying the Pd content over a large range from 0.1 wt % to 10 wt %, we were able to directly analyze the influence of the Pd content on activity and selectivity. In addition to catalytic measurements, the structure and composition of the particles were characterized before and after these measurements, using transmission electron microscopy, adsorption measurements, X-ray diffraction and EXAFS. The comparison revealed, on the one hand, that small Pd clusters (diameter: 1-2 nm) evolve from initially homogeneously distributed Pd and, on the other hand, that the iron oxide transforms into iron carbides depending on the Pd content. The presence of Pd influences the particle size in the pristine samples (8 - 11 nm), resulting in specific surface areas that increase as the Pd content increases. However, after activation and reaction the specific surface areas become similar due to partial agglomeration and sintering. In a fixed bed FT reaction test, enhanced FT activity was observed with increasing Pd content while the selectivity shifts to longer chain hydrocarbons, mainly paraffins. (orig.)

  3. An alternative fluorine precursor for the synthesis of SnO2:F by spray pyrolysis

    International Nuclear Information System (INIS)

    Arca, E.; Fleischer, K.; Shvets, I.V.

    2012-01-01

    An alternative, non-toxic precursor was employed for the synthesis of SnO 2 :F transparent conducting oxide. The performance of benzenesulfonyl fluoride (BSF) as F source for spray pyrolysis was investigated. Its decomposition and the actual incorporation of fluorine in the tin oxide matrix were confirmed by X-ray photoelectron spectroscopy while its effect on the electrical properties was investigated by resistance and Hall measurements. Results were compared with respect to samples grown using a common fluorine source (NH 4 F), a commercial available sample and a sample grown by spray pyrolysis at an independent laboratory. We show that BSF leads to actively doped conductive SnO 2 with good carrier mobility, though the fluorine incorporation rate and hence overall conductivity of the films is lower than for fluorine precursors commonly used in spray pyrolysis.

  4. Production, properties and utilisation of pyrolysis oil

    Energy Technology Data Exchange (ETDEWEB)

    Sipilae, K; Oasmaa, A; Arpiainen, V; Solantausta, Y; Leppaemaeki, E; Kuoppala, E; Levander, J; Kleemola, J; Saarimaeki, P [VTT Energy, Jyvaeskylae (Finland). Energy Production Technologies

    1997-12-01

    In this project VTT Energy co-ordinates the EU JOULE Project `Biofuel oil for power plants and boilers` supporting the development projects of Finnish enterprises, and participates in the Pyrolysis Project of IEA Bioenergy Agreement. Presently two pyrolysis devices with capacities of 150 g/h and 1 kg/h are used for the project. Hot gas filtering tests by using one ceramic candle equipment have been carried out with the 1 kg/h device for pyrolysis oil. The solids and alkali contents of the product oil were reduced clearly. Suitable conditions are being defined for continuous hot gas filtering. A PDU device of 20 kg/h is being commissioned. The main aim of the chemical characterisation of pyrolysis oil was to develop as simple a method as possible for differentiating pyrolysis oils and for finding correlations between the characteristics and behaviour of pyrolysis oils. Pyrolysis oils produced from various raw materials (hardwood, pine, straw) were analysed and compared with each other. VTT Energy participates in the pyrolysis network (EU/PYNE) of EU, the aim of which is to collect and disseminate research results of pyrolysis studies, i.e., through a journal with a wide circulation. VTT also participates in the pyrolysis activity of IEA (PYRA), the other partners being Great Britain, EU, Canada and the United States. I.e., quality criteria and improvement, occupational safety and pyrolysis kinetics are discussed in IEA/PYRA

  5. Biofuel from jute stick by pyrolysis technology

    Science.gov (United States)

    Ferdous, J.; Parveen, M.; Islam, M. R.; Haniu, H.; Takai, K.

    2017-06-01

    In this study the conversion of jute stick into biofuels and chemicals by externally heated fixed-bed pyrolysis reactor have been taken into consideration. The solid jute stick was characterized through proximate and ultimate analysis, gross calorific values and thermo-gravimetric analysis to investigate their suitability as feedstock for this consideration. The solid biomass particles were fed into the reactor by gravity feed type reactor feeder. The products were oil, char and gases. The liquid and char products were collected separately while the gas was flared into the atmosphere. The process conditions were varied by fixed-bed temperature; feed stock particle size, N2 gas flow rate and running time. All parameters were found to influence the product yields significantly. The maximum liquid yields were 50 wt% of solid jute stick at reactor temperature 425°C for N2 gas flow rate 6 l/min, feed particle size 1180-1700 µm and running time 30 min. Liquid products obtained at these conditions were characterized by physical properties, chemical analysis and GC-MS techniques. The results show that it is possible to obtained liquid products that are comparable to petroleum fuels and valuable chemical feedstock from the selected biomass if the pyrolysis conditions are chosen accordingly.

  6. The structure and pyrolysis product distribution of lignite from different sedimentary environment

    International Nuclear Information System (INIS)

    Liu, Peng; Zhang, Dexiang; Wang, Lanlan; Zhou, Yang; Pan, Tieying; Lu, Xilan

    2016-01-01

    Highlights: • Carbon structure of three lignites was measured by solid "1"3C NMR. • Effect of carbon structure on pyrolysis product distribution was studied. • Tar yield is influenced by aliphatic carbon and oxygen functional group. • C1–C4 content of pyrolysis gas is related to CH_2/CH_3 ratio. - Abstract: Low-temperature pyrolysis is an economically efficient method for lignite to obtain coal tar and improve its combustion calorific value. The research on the distribution of pyrolysis product (especially coal tar yield) plays an important role in energy application and economic development in the now and future. Pyrolysis test was carried out in a tube reactor at 873 K for 15 min. The structure of the lignite was measured by solid "1"3C nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR). The thermal analysis was analyzed by thermo-gravimetric (TG) analyzer. The results show that the pyrolysis product distribution is related to the breakage of branch structures of aromatic ring in lignites from different sedimentary environment. The gas yield and composition are related to the decomposition of carbonyl group and the breakage of aliphatic carbon. The tar yield derived from lignite pyrolysis follows the order: Xianfeng lignite (XF, 13.67 wt.%) > Xiaolongtan lignite (XLT, 7.97 wt.%) > Inner Mongolia lignite (IM, 6.30 wt.%), which is mainly influenced by the aliphatic carbon contents, the CH_2/CH_3 ratio and the oxygen functional groups in lignite. The pyrolysis water yield depends on the decomposition of oxygen functional groups. IM has the highest content of oxygen-linked carbon so that the pyrolysis water yield derived from IM is the highest (9.20 wt.%), and is far more than that from the other two lignites.

  7. Morphological characteristics of waste polyethylene/polypropylene plastics during pyrolysis and representative morphological signal characterizing pyrolysis stages.

    Science.gov (United States)

    Wang, H; Chen, D; Yuan, G; Ma, X; Dai, X

    2013-02-01

    In this work, the morphological characteristics of waste polyethylene (PE)/polypropylene (PP) plastics during their pyrolysis process were investigated, and based on their basic image changing patterns representative morphological signals describing the pyrolysis stages were obtained. PE and PP granules and films were used as typical plastics for testing, and influence of impurities was also investigated. During pyrolysis experiments, photographs of the testing samples were taken sequentially with a high-speed infrared camera, and the quantitative parameters that describe the morphological characteristics of these photographs were explored using the "Image Pro Plus (v6.3)" digital image processing software. The experimental results showed that plastics pyrolysis involved four stages: melting, two stages of decomposition which are characterized with bubble formation caused by volatile evaporating, and ash deposition; and each stage was characterized with its own phase changing behaviors and morphological features. Two stages of decomposition are the key step of pyrolysis since they took up half or more of the reaction time; melting step consumed another half of reaction time in experiments when raw materials were heated up from ambient temperatures; and coke-like deposition appeared as a result of decomposition completion. Two morphological signals defined from digital image processing, namely, pixel area of the interested reaction region and bubble ratio (BR) caused by volatile evaporating were found to change regularly with pyrolysis stages. In particular, for all experimental scenarios with plastics films and granules, the BR curves always exhibited a slowly drop as melting started and then a sharp increase followed by a deep decrease corresponding to the first stage of intense decomposition, afterwards a second increase - drop section corresponding to the second stage of decomposition appeared. As ash deposition happened, the BR dropped to zero or very low

  8. Influence of ligands on the photoluminescent properties of Eu3+ in europium β-diketonate/PMMA-doped systems

    International Nuclear Information System (INIS)

    Liu, H.-G.; Park, Seongtae; Jang, Kiwan; Feng, X.-S.; Kim, Changdae; Seo, H.-J.; Lee, Y.-I.

    2004-01-01

    Three kinds of europium β-diketonates Eu(DBM) 3 , Eu(BA) 3 and Eu(TTA) 3 (DBM: Dibenzoylmethane; BA: 1-Benzoylacetone; TTA: Thenoyltrifluoroacetone) were doped in poly(methyl methacrylate) (PMMA) matrix. The doped systems were studied by using photoluminescent (PL) spectroscopy, emission decay experiments and X-ray diffractometry. Eu(III) ions in the doped Eu(DBM) 3 /PMMA systems have two distinct symmetric sites and the emission band changes greatly with the compositions. Eu(III) in the Eu(BA) 3 /PMMA systems gives only one symmetric site in the doped systems and the emission band changes slightly with the compositions. Although two distinct symmetric sites of Eu(III) can be distinguished in the doped systems of Eu(TTA) 3 /PMMA, the two sites have similar 5 D 0 lifetimes and the luminescent spectra almost do not change with the compositions. XRD reveals that crystallites were formed in the doped Eu(DBM) 3 /PMMA systems that have different crystalline structure from that of the chelate, and Eu(BA) 3 and Eu(TTA) 3 exist in amorphous state in the doped systems. The difference between the PL properties and structures of the doped systems for the three kinds of chelates should be attributed to different interactions between the chelate molecules and between the chelate and PMMA

  9. Resistive switching phenomena of extended defects in Nb-doped SrTiO3 under influence of external gradients

    International Nuclear Information System (INIS)

    Rodenbuecher, Christian

    2014-01-01

    Redox-based memristive materials have attracted much attention in the last decade owing to their ability to change the resistance upon application of an electric field making them promising candidates for future non-volatile memories. However, a fundamental understanding of the nature of the resistive switching effect, which is indispensable for designing future technological applications,is still lacking. As a prototype material of a memristive oxide, strontium titanate (SrTiO 3 ) has been investigated intensively and it was revealed that the valence change of a Ti ''d'' electron plays an important role during resistive switching related to insulator-to-metal transition. Such a transition can be induced by electrical gradients, by chemical gradients, by a combination of these gradients or by donor doping. Hence, SrTiO 3 doped with the donor Nb should have metallic properties and is used commonly as a conducting substrate for the growth of functional oxide thin films. Nevertheless,the resistive switching effect has also be observed in Nb-doped SrTiO 3 . This paradoxical situation offers a unique opportunity to gain an insight into the processes during the insulator-to metal transition. In this thesis, a comprehensive study of the influence of external gradients on SrTiO 3 :Nb single crystals is presented. The focus is especially set on the investigation of the crystallographic structure, the chemical composition, the electronic structure, the lattice dynamics and the electronic transport phenomena using surface-sensitive methods on the macro- and nanoscale. On the as-received epi-polished single crystals, the evolution of a surface layer having a slight excess of strontium and - in contrast to the bulk of the material - semiconducting properties are observed. Hence, the key for understanding of the resistive switching effect is the knowledge of the nature of the surface layer. On the basis of systematic studies of the influence of external

  10. Integrated biomass pyrolysis with organic Rankine cycle for power generation

    Science.gov (United States)

    Nur, T. B.; Syahputra, A. W.

    2018-02-01

    The growing interest on Organic Rankine Cycle (ORC) application to produce electricity by utilizing biomass energy sources are increasingly due to its successfully used to generate power from waste heat available in industrial processes. Biomass pyrolysis is one of the thermochemical technologies for converting biomass into energy and chemical products consisting of liquid bio-oil, solid biochar, and pyrolytic gas. In the application, biomass pyrolysis can be divided into three main categories; slow, fast and flash pyrolysis mainly aiming at maximizing the products of bio-oil or biochar. The temperature of synthesis gas generated during processes can be used for Organic Rankine Cycle to generate power. The heat from synthesis gas during pyrolysis processes was transfer by thermal oil heater to evaporate ORC working fluid in the evaporator unit. In this study, the potential of the palm oil empty fruit bunch, palm oil shell, and tree bark have been used as fuel from biomass to generate electricity by integrated with ORC. The Syltherm-XLT thermal oil was used as the heat carrier from combustion burner, while R245fa was used as the working fluid for ORC system. Through Aspen Plus, this study analyses the influences on performance of main thermodynamic parameters, showing the possibilities of reaching an optimum performance for different working conditions that are characteristics of different design parameters.

  11. Study on the Inference Factors of Huangling Coking Coal Pyrolysis

    Science.gov (United States)

    Du, Meili; Yang, Zongyi; Fan, Jinwen

    2018-01-01

    In order to reasonably and efficiently utilize Huangling coking coal resource, coal particle, heating rate, holding time, pyrolysis temperature and others factors were dicussed for the influence of those factor on Huangling coking coal pyrolysis products. Several kinds of coal blending for coking experiments were carried out with different kinds of coal such as Huangling coking coal, Xida coal with high ash low sufur, Xinghuo fat coal with hign sulfur, Zhongxingyi coking coal with high sulfur, Hucun lean coal, mixed meager and lean coal. The results shown that the optimal coal particle size distribution was 0.5~1.5mm, the optimal heating rate was 8°C/min, the optimal holding time was 15min, the optimal pyrolysis temperature was 800°C for Huangling coking coal pyrolysis, the tar yield increased from 4.7% to 11.2%. The maximum tar yield of coal blending for coking under the best single factor experiment condition was 10.65% when the proportio of Huangling coking coal was 52%.

  12. Influence of stacking morphology and edge nitrogen doping on the dielectric performance of graphene-polymer nanocomposites

    KAUST Repository

    Almadhoun, Mahmoud N.

    2014-05-13

    We demonstrate that functional groups obtained by varying the preparation route of reduced graphene oxide (rGO) highly influence filler morphology and the overall dielectric performance of rGO-relaxor ferroelectric polymer nanocomposite. Specifically, we show that nitrogen-doping by hydrazine along the edges of reduced graphene oxide embedded in poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) results in a dielectric permittivity above 10 000 while maintaining a dielectric loss below 2. This is one of the best-reported dielectric constant/dielectric loss performance values. In contrast, rGO produced by the hydrothermal reduction route shows a much lower enhancement, reaching a maximum dielectric permittivity of 900. Furthermore, functional derivatives present in rGO are found to strongly affect the quality of dispersion and the resultant percolation threshold at low loading levels. However, high leakage currents and lowered breakdown voltages offset the advantages of increased capacitance in these ultrahigh-k systems, resulting in no significant improvement in stored energy density. © 2014 American Chemical Society.

  13. Influence of Nd-Doping on Photocatalytic Properties of TiO2 Nanoparticles and Thin Film Coatings

    Directory of Open Access Journals (Sweden)

    Damian Wojcieszak

    2014-01-01

    Full Text Available Structural, optical, and photocatalytic properties of TiO2 and TiO2:Nd nanopowders and thin films composed of those materials have been compared. Titania nanoparticles with 1, 3, and 6 at. % of Nd-dopant were synthesized by sol-gel method. Additionally, thin films with the same material composition were prepared with the aid of spin-coating method. The analysis of structural investigations revealed that all as-prepared nanopowders were nanocrystalline and had TiO2-anatase structure. The average size of crystallites was ca. 4-5 nm and the correlation between the amount of neodymium and the size of TiO2 crystallites was observed. It was shown that the dopant content influenced the agglomeration of the nanoparticles. The results of photocatalytic decomposition of MO showed that doping with Nd (especially in the amount of 3 at. % increased self-cleaning activity of the prepared titania nanopowder. Similar effect was received in case of the thin films, but the decomposition rate was lower due to their smaller active surface area. However, the as-prepared TiO2:Nd photocatalyst in the form of thin films or nanopowders seems to be a very attractive material for various applications.

  14. Influence of reaction conditions and the char separation system on the production of bio-oil from radiata pine sawdust by fast pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hyun Ju; Park, Young-Kwon; Kim, Joo Sik [Faculty of Environmental Engineering, University of Seoul, 90 Jeonnong-Dong, Dondaemun-Gu, Seoul 130-743 (Korea)

    2008-08-15

    Radiata pine sawdust was pyrolyzed in a bubbling fluidized bed equipped with a char separation system. The influence of the reaction conditions on the production of bio-oil was investigated through the establishment of mass balance, and the examination of the products' chemical and physical characteristics. The optimal reaction temperature for the production of bio-oil was between 673 and 723 K, and the yield was above 50 wt.% of the product. An optimal feed size also existed. In a particle with a size that was less than 0.3 mm, the bio-oil yield decreased due to overheating, which led to gas formation. A higher flow rate and feeding rate were found to be more effective for the production of bio-oil, but did not significantly affect it. The main compounds of bio-oil were phenolics, including cresol, guaiacol, eugenol, benzendiol and their derivatives, ketones, and aldehydes. In addition, high-quality bio-oils, which contained less than 0.005 wt.% of solid, no ash and low concentrations of alkali and alkaline earth metals, were produced due to the char removal system. (author)

  15. Fast pyrolysis of lignin, macroalgae and sewage sludge

    Energy Technology Data Exchange (ETDEWEB)

    Trinh, N.T.

    2013-04-15

    macronutrients as N, P, K, S, Mg and Ca and this could make the chars most valuable as raw materials for fertilizer production. The sewage sludge waste bulk volume (the char compared to the sludge) was reduced with 52 % by pyrolysis at 575 deg. C. It is seen that the fast pyrolysis process provides a promising method to reduce cost for landfilling and produce a bio-oil that can be used as a fuel. The pyrolysis temperature has a considerable effect on the product distributions of the lignin and sewage sludge PCR pyrolysis, as well as their bio-oil properties with respect to molecular mass distribution, identified GC-MS component compositions, water-insoluble fraction, viscosity, and HHV. A maximum of organic oil yields of lignin and sewage sludge PCR pyrolysis were obtained at optimal temperatures of 550 - 575 deg. C. In this work, the behaviors of slurry samples of wood, char and grinded char with respect to phase transitions, rheological properties, elemental composition, and energy density were investigated. Also pumping properties were investigated at temperatures of 25, 40 and 60 deg. C and the solids loading of 0 - 20 wt%. The bioslurries obtained a volume energy density of 21-23 GJ/m{sup 3} and an energy densification factor of 4.5 - 5 (when compared to beech wood). Their apparent viscosities were significantly influenced by the solid loading levels (0 - 20 wt %) and temperatures (25 - 60 deg. C). The slurry samples with 10 wt% char (having d80 of 276 {mu}m) and 20 wt% grinded char (having d80 of 118 {mu}m) were successfully pumped into a pressurized chamber (0 - 6 bar). (LN)

  16. Influence of different preparation conditions on catalytic activity of ag /gama-al/sub 2/o/sub 3/ for hydrogenation of coal slime pyrolysis

    International Nuclear Information System (INIS)

    Lei, Z.; Rong, C.

    2014-01-01

    This paper, introducing variable conditional factors with Ag/AL/sub 2/O/sub 3/ as catalyst, selects five variables to investigate the influences of experimental conditions on Ag/Al2O/sub 3/ catalytic activity and define the optimal process conditions. These variables include Ag loading amount, calcinations temperature, calcinations time, reduction temperature, reduction time. X ray diffraction (XRD), hydrogen temperature-programmed reduction (TPR), X ray photoelectron spectrum (XPS) and scanning electron microscopy (SEM) were utilized to characterize the catalytic activity of Ag/-Al/sub 2/O/sub 3/, active center structure and state and those of carrier were emphatically studied, In the meantime the effects of active center and carrier on catalytic activity are studied. The results showed that: (1) In the range of 600 degree C-900 degree C, the catalytic activity of Ag/-Al/sub 2/O/sub 3/ with different loading showed little difference when changing loading amount, in the range of 900 degree C-1100 degree C, when the loading was 5%, the catalytic activity was very high; From the XRD and SEM characterizations, when the loading was 5%, it showed strong intensity diffraction peak of Ag crystal, crystal Ag is the most important activity center to promote hydrogen yield. (2) the catalytic activity of Ag/-Al/sub 2/O/sub 3/ at 450 degree C was considerably higher than that at 400 degree C and 500 degree C. By BET, XRD and SEM characterization, it can be seen, the diffraction peaks intensity of Ag crystal at 450 degree C is higher and sharper than that at 400 degree C and 500 degree C and with the increase of calcinations temperature, the specific surface area of catalysts also increased. (3) In the range of 600 degree C - 1000 degree C, the effects of calcinations time can be negligible, while, with temperature higher than 1000 degree C, 4-hour-calcinations-time catalyst exhibits a more noticeable catalytic activity than 3-hour and 5-hour catalyst do; From the XRD

  17. Influence of zirconium doping on the activities of zirconium and iodine co-doped titanium dioxide in the decolorization of methyl orange under visible light irradiation

    International Nuclear Information System (INIS)

    Song Shuang; Hong Fangyue; He Zhiqiao; Wang Hongyu; Xu Xianghong; Chen Jianmeng

    2011-01-01

    Zirconium and iodine co-doped titanium dioxide (Zr-I-TiO 2 ) was prepared by the hydrolysis of tetrabutyl titanate, premixed with zirconium nitrate in an iodic acid aqueous solution, followed by calcination in air. The structure and properties of the resultant catalyst powders were characterized by X-ray diffraction, the Brunauer-Emmett-Teller method, X-ray photoelectron spectroscopy, transmission electron microscopy, and UV-vis absorption spectroscopy. The catalytic activity of the catalyst was evaluated by monitoring the photocatalytic decolorization of methyl orange under visible light irradiation. The results showed that the activities of Zr-I-TiO 2 catalysts were higher than that of TiO 2 doped with iodine alone (I-TiO 2 ), and the optimal doping concentration in the Zr-I-TiO 2 calcined at 400 deg. C was determined to be about 0.05 (molar ratio of Zr:Ti). In addition, the photocatalytic activity of Zr-I-TiO 2 calcined at 400 deg. C was found to be significantly higher than that calcined at 500 or 600 deg. C. Based on the physico-chemical characterization, we concluded that the role of zirconium on the I-TiO 2 surface is to increase the number of reactive sites by generating a small crystal size and large surface area. The inhibition of electron-hole pair recombination, by trapping photo-generated electrons with Zr 4+ , did not contribute markedly to the improved photocatalytic activity of Zr-I-TiO 2 .

  18. Pyrolysis of rubber gloves in integral pyrolysis test plant

    International Nuclear Information System (INIS)

    Norasalwa Zakaria; Mohd Noor Muhd Yunus; Mohd Annuar Assadat Husain; Farid Nasir Ani

    2010-01-01

    Previously, pyrolysis of rubber gloves in laboratory study was described. In order to visualize the practical application of rubber gloves pyrolysis in terms of treating rubber gloves in medical waste, a new test plant was designed and constructed. The semi-continuous test plant was designed to accommodate rubber gloves that were not cut or shredded. The test plant has a capacity of 2kg/ hr and employed auxiliary fuel instead of the conventional electrical power for heating. The concept was based on moving bed reactor, but additional feature of sand jacket feature was also introduced in the design. Pyrolysis of the gloves was conducted at three temperatures, namely 350 degree Celsius, 400 degree Celsius and 450 degree Celsius. Oxygen presents inside of the reactor due to the combined effect of imperfect sealing and suction effect. This study addresses the performance of this test plant covering the time temperature profile, gas evolution profile and product yield. Comparison between the yield of the liquid, gas and char pyrolyzate was made against the laboratory study. It was found that the oil yield was less than the one obtained from bench scale study. Water formation was more pronounced. The presence of the oxygen also altered the tail gas composition but eliminate the sticky nature of solid residue, making it easier to handle. The chemical composition of the oil was determined and the main compounds in the oil were esters and phtalic acid. (author)

  19. Fast pyrolysis of biomass at high temperatures

    DEFF Research Database (Denmark)

    Trubetskaya, Anna

    This Ph.D. thesis describes experimental and modeling investigations of fast high temperature pyrolysis of biomass. Suspension firing of biomass is widely used for power generation and has been considered as an important step in reduction of greenhouse gas emissions by using less fossil fuels. Fast...... to investigate the effects of operating parameters and biomass types on yields of char and soot, their chemistry and morphology as well as their reactivity using thermogravimetric analysis. The experimental study was focused on the influence of a wide range of operating parameters including heat treatment...... alkali metals. In this study, potassium lean pinewood (0.06 wt. %) produced the highest soot yield (9 and 7 wt. %) at 1250 and 1400°C, whereas leached wheat straw with the higher potassium content (0.3 wt. %) generated the lowest soot yield (2 and 1 wt. %). Soot yields of wheat and alfalfa straw at both...

  20. Zinc oxide films prepared by spray pyrolysis

    Directory of Open Access Journals (Sweden)

    Maciąg Andrzej

    2017-01-01

    Full Text Available In this work we developed and tested spray pyrolysis system for layers deposition. In the system we have used ultrasonic apparatus (nebulizator as a sprayer. A zinc nitrate aqueous solution has been used as a precursor solution. The idea of the method is the decomposition of nitrate on a hot substrate according to the reaction Zn(NO32 → ZnO +2 NO2 +1/2O2. The layers were grown on glass, (001Si and KCl substrates at the temperatures 300 – 500°C. The thickness of the obtained layers was in the range 50 – 500 nm, depending on the growth time and rate. The influence of substrate temperature on the morphology of the layers has been studied by SEM method. The energy gap of the layers was found to be the range of 3.26-3.3 eV from their absorption spectra.

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

    International Nuclear Information System (INIS)

    Chen, J.-C.; Chang, C.-L.; Hsu, C.-S.; Hwang, B.-H.

    2007-01-01

    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 Ω cm 2 at 550 deg. C was obtained

  2. Slow pyrolysis of pistachio shell

    Energy Technology Data Exchange (ETDEWEB)

    Apaydin-Varol, Esin; Putun, Ersan; Putun, Ayse E [Anadolu University, Eskisehir (Turkey). Department of Chemical Engineering

    2007-08-15

    In this study, pistachio shell is taken as the biomass sample to investigate the effects of pyrolysis temperature on the product yields and composition when slow pyrolysis is applied in a fixed-bed reactor at atmospheric pressure to the temperatures of 300, 400, 500, 550, 700{sup o}C. The maximum liquid yield was attained at about 500-550{sup o}C with a yield of 20.5%. The liquid product obtained under this optimum temperature and solid products obtained at all temperatures were characterized. As well as proximate and elemental analysis for the products were the basic steps for characterization, column chromatography, FT-IR, GC/MS and SEM were used for further characterization. The results showed that liquid and solid products from pistachio shells show similarities with high value conventional fuels. 31 refs., 9 figs., 1 tab.

  3. Catalytic Fast Pyrolysis: A Review

    Directory of Open Access Journals (Sweden)

    Theodore Dickerson

    2013-01-01

    Full Text Available Catalytic pyrolysis is a promising thermochemical conversion route for lignocellulosic biomass that produces chemicals and fuels compatible with current, petrochemical infrastructure. Catalytic modifications to pyrolysis bio-oils are geared towards the elimination and substitution of oxygen and oxygen-containing functionalities in addition to increasing the hydrogen to carbon ratio of the final products. Recent progress has focused on both hydrodeoxygenation and hydrogenation of bio-oil using a variety of metal catalysts and the production of aromatics from bio-oil using cracking zeolites. Research is currently focused on developing multi-functional catalysts used in situ that benefit from the advantages of both hydrodeoxygenation and zeolite cracking. Development of robust, highly selective catalysts will help achieve the goal of producing drop-in fuels and petrochemical commodities from wood and other lignocellulosic biomass streams. The current paper will examine these developments by means of a review of existing literature.

  4. Microwave pyrolysis for conversion of materials to energy : A review

    International Nuclear Information System (INIS)

    Mokhtar, M.; Omar, R.; MOhammad Salleh, M.A.; Idris, A.

    2009-01-01

    Full text: The disposal of wastes in Malaysia is becoming a serious problem in many industrialized and public sectors. This is due to the high production of waste such as municipal solid waste, sludge from waste water treatment plants, agricultural waste and other used non-biodegradable products such as plastics and tyres. These wastes although are reused as compost, fuel, recycled and so on, there are still abundant left. These leftovers pose problems such as heavy metal leaching, leachates, green house gas emissions and mosquito breeding grounds. The disposal cost of these wastes sometimes can be costly at up to RM 2,200/ ton such as petroleum sludge by Kualiti Alam. Several methods have been used to convert these residues to energy via thermal treatment such as combustion, incineration and gasification. However, pyrolysis becomes one of the popular methods as the alternative to the wastes disposal recently. Not only energy (as gas) is produced, by-products such as chemical feedstock and solid absorbent can be produced. The use of microwave for pyrolysis, although relatively new for waste treatment, has several advantages compared to conventional heating. This includes easy control of the heating process, time saving, higher heating efficiency, etc. Tyre microwave pyrolysis plant in UK is known as the earliest plant using microwave technology to breakdown polymer in used tyres. Since 1990s, there are many patents for microwave pyrolysis. The processes are based on microwave pyrolysis of waste include coffee hulls, wood, coal, sewage sludge, hospital waste, plastic wastes, corn cobs and rice straw. The most important factors influencing the yield of product during the pyrolysis is temperature in range from 500 to 1000 degree Celsius according to product preference. High temperature favors gas products; whereas lower temperature favors liquid products. Comparatively, microwave pyrolysis produced gas with higher hydrogen and carbon monoxide (syngas) content compared

  5. Desulfurized gas production from vertical kiln pyrolysis

    Science.gov (United States)

    Harris, Harry A.; Jones, Jr., John B.

    1978-05-30

    A gas, formed as a product of a pyrolysis of oil shale, is passed through hot, retorted shale (containing at least partially decomposed calcium or magnesium carbonate) to essentially eliminate sulfur contaminants in the gas. Specifically, a single chambered pyrolysis vessel, having a pyrolysis zone and a retorted shale gas into the bottom of the retorted shale zone and cleaned product gas is withdrawn as hot product gas near the top of such zone.

  6. Modelling solid-convective flash pyrolysis of straw and wood in the Pyrolysis Centrifuge Reactor

    DEFF Research Database (Denmark)

    Bech, Niels; Larsen, Morten Boberg; Jensen, Peter Arendt

    2009-01-01

    in the Pyrolysis Centrifuge Reactor, a novel solid-convective flash pyrolysis reactor. The model relies on the original concept for ablative pyrolysis of particles being pyrolysed through the formation of an intermediate liquid compound which is further degraded to form liquid organics, char, and gas. To describe...

  7. The influence of Ti doping and annealing on Ce_2Ti_2O_7 flash memory devices

    International Nuclear Information System (INIS)

    Kao, Chyuan Haur; Chen, Su Zhien; Luo, Yang; Chiu, Wang Ting; Chiu, Shih Wei; Chen, I Chien; Lin, Chan-Yu; Chen, Hsiang

    2017-01-01

    Highlights: • Ce_2Ti_2O_7 flash memories have been fabricated. • Material quality can be improved by annealing. • The memory performance can be enhanced by Ti doping. • Ti doping and annealing can reinforce crystallization. - Abstract: In this research, a CeO_2 film with Ti doping was used as a trapping layer in metal oxide high-K-oxide-Si (MOHOS)-type memory devices. Since incorporation of Ti atoms into the film could fix dangling bonds and defects, the Ce_2Ti_2O_7 trapping layer with annealing treatment could have a larger memory window and a faster programming/erasing speed. To confirm the origin, multiple material analyses indicate that annealing at an appropriate temperature and Ti doping could enhance crystallization. The Ce_2Ti_2O_7-based memory device is promising for future industrial flash memory applications.

  8. Understanding the fast pyrolysis of lignin.

    Science.gov (United States)

    Patwardhan, Pushkaraj R; Brown, Robert C; Shanks, Brent H

    2011-11-18

    In the present study, pyrolysis of corn stover lignin was investigated by using a micro-pyrolyzer coupled with a GC-MS/FID (FID=flame ionization detector). The system has pyrolysis-vapor residence times of 15-20 ms, thus providing a regime of minimal secondary reactions. The primary pyrolysis product distribution obtained from lignin is reported. Over 84 % mass balance and almost complete closure on carbon balance is achieved. In another set of experiments, the pyrolysis vapors emerging from the micro-pyrolyzer are condensed to obtain lignin-derived bio-oil. The chemical composition of the bio-oil is analyzed by using GC-MS and gel permeation chromatography techniques. The comparison between results of two sets of experiments indicates that monomeric compounds are the primary pyrolysis products of lignin, which recombine after primary pyrolysis to produce oligomeric compounds. Further, the effect of minerals (NaCl, KCl, MgCl(2), and CaCl(2)) and temperature on the primary pyrolysis product distribution is investigated. The study provides insights into the fundamental mechanisms of lignin pyrolysis and a basis for developing more descriptive models of biomass pyrolysis. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Influence of VB group doped TiO2 on photovoltaic performance of dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Liu, Jia; Duan, Yandong; Zhou, Xiaowen; Lin, Yuan

    2013-01-01

    Dye-sensitized solar cell with V B group (vanadium (V), niobium (Nb) and tantalum (Ta)) doped TiO 2 prepared by hydrothermal method shows a higher photovoltaic efficiency compared with the undoped TiO 2 . All the V B doping shift the flat band potential positively and increase the doping density which is investigated by Mott–Schottky plot. The positive shift of flat band potential improves the driving force of injecting electron from the LUMO of dye to the conduction band of TiO 2 and the photocurrent. On the other hand, the increase of doping density accelerates transfer rate of electrons in TiO 2 than the un-doped, which is confirmed by intensity-modulated photocurrent. V-, Nb-, Ta-doped TiO 2 exhibited photovoltaic performance with 7.80%, 8.33%, 8.18%, respectively, compared with that of the cells based on pure TiO 2 (7.42%).

  10. Influence of Doping Concentration on Dielectric, Optical, and Morphological Properties of PMMA Thin Films

    Directory of Open Access Journals (Sweden)

    Lyly Nyl Ismail

    2012-01-01

    Full Text Available PMMA thin films were deposited by sol gel spin coating method on ITO substrates. Toluene was used as the solvent to dissolve the PMMA powder. The PMMA concentration was varied from 30 ~ 120 mg. The dielectric properties were measured at frequency of 0 ~ 100 kHz. The dielectric permittivity was in the range of 7.3 to 7.5 which decreased as the PMMA concentration increased. The dielectric loss is in the range of 0.01 ~ –0.01. All samples show dielectric characteristics which have dielectric loss is less than 0.05. The optical properties for thin films were measured at room temperature across 200 ~ 1000 nm wavelength region. All samples are highly transparent. The energy band gaps are in the range of 3.6 eV to 3.9 eV when the PMMA concentration increased. The morphologies of the samples show that all samples are uniform and the surface roughness increased as the concentration increased. From this study, it is known that, the dielectric, optical, and morphology properties were influenced by the amount of PMMA concentration in the solution.

  11. Nanoferrites of nickel doped with cobalt: Influence of Co{sup 2+} on the structural and magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, A.P.G. [Federal University of Rio Grande do Norte, Chemical Institute, Natal-RN 59078-970 (Brazil); Gomes, D.K.S., E-mail: dkarinne@yahoo.com.br [Federal University of Rio Grande do Norte, Graduate Program in Materials Science and Engineering, Laboratory of Catalysis and Materials, Natal-RN 59078-970 (Brazil); Coordination of Improvement of Higher Education Personnel, CAPES/PNPD (Brazil); Araújo, J.H., E-mail: humberto@dfte.ufrn.br [Federal University of Rio Grande do Norte, Department of Theoretical and Experimental Physics, Laboratory of Magnetism and Magnetic Materials, Natal-RN 59078-970 (Brazil); Melo, D.M.A., E-mail: daraujomelo@gmail.com [Federal University of Rio Grande do Norte, Chemical Institute, Natal-RN 59078-970 (Brazil); Oliveira, N.A.S. [Federal University of Rio Grande do Norte, Chemical Institute, Natal-RN 59078-970 (Brazil); Braga, R.M., E-mail: renata@cear.ufpb.br [Federal University of Paraíba, DEER-CEAR, João Pessoa–PB 58051-970 (Brazil)

    2015-01-15

    Nanoferrites of nickel substituted with cobalt of composition Ni{sub 1−x}Co{sub x}Fe{sub 2}O{sub 4} (0≤x≤0.75), were synthesized by combustion reaction assisted in microwaves. The influence of the substitution of Ni{sup 2+} by Co{sup 2+} content and the concentration of Co{sup 2+} in the structural and magnetic properties was investigated. The powders were prepared by combustion according to the concept of chemical propellants and heated in a microwave oven with a power of 7000 kW. The synthesized powders were characterized by absorption spectroscopy in the infrared region (FTIR), X-ray diffraction (XRD) together with Rietveld refinement, surface area (BET) method, scanning electron microscopy (MEV) and magnetic measurements (MAV). The results indicated that it was possible to obtain nickel ferrite doped with cobalt in all compositions and that an increase of cobalt concentration caused an increase in particle size (9.78–21.63 nm), a reduction in surface area, and reduction in magnetic concentrations greater than 50%. - Highlights: • Nanoferrites Ni{sub 1–x}Co{sub x}Fe{sub 2}O{sub 4}(0≤x≤0.75) synthesized by combustion reaction assisted. • The structural and magnetic properties of substitution of Ni{sup 2+} by Co{sup 2+} were investigate. • Combustion reaction takes spinel phase with suitable magnetic properties. • The ferrites presented characteristics of soft and intermediate magnetic materials.

  12. Effect of Zn doping on optical properties and photoconductivity of ...

    Indian Academy of Sciences (India)

    Keywords. Thin film; spray pyrolysis; tin sulfide; optical properties; photoluminescence; photoconductivity. 1. ... ber of compounds with CdI2 structure, has interesting proper- ties such .... STM images of 0, 2·5, 5 and 7·5 at% Zn-doped SnS2 films.

  13. Room temperature ferromagnetism and gas sensing in ZnO nanostructures: Influence of intrinsic defects and Mn, Co, Cu doping

    Energy Technology Data Exchange (ETDEWEB)

    Mhlongo, Gugu H., E-mail: gmhlongo@csir.co.za [DST/CSIR National Centre for Nanostructured Materials, Council for Scientific and Industrial Research, Pretoria 0001 (South Africa); Shingange, Katekani; Tshabalala, Zamaswazi P.; Dhonge, Baban P. [DST/CSIR National Centre for Nanostructured Materials, Council for Scientific and Industrial Research, Pretoria 0001 (South Africa); Mahmoud, Fawzy A. [Solid State Physics Dept., National Research Centre, P.O. 12622, Dokki, Giza (Egypt); Mwakikunga, Bonex W.; Motaung, David E. [DST/CSIR National Centre for Nanostructured Materials, Council for Scientific and Industrial Research, Pretoria 0001 (South Africa)

    2016-12-30

    Highlights: • Preparation of Mn, Co, Cu doped ZnO via microwave-assisted method. • Doping alters the morphology of ZnO nanostructures. • Concentration of zinc and oxygen related defects vary with doping. • Correlation between PL and EPR was established. • Both undoped and doped ZnO nanostructures showed selectivity towards NH{sub 3}. - Abstract: Undoped and transition metal (Cu, Co and Mn) doped ZnO nanostructures were successfully prepared via a microwave-assisted hydrothermal method followed by annealing at 500 °C. Numerous characterization facilities such as X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), and high-resolution transmission electron microscopy (HRTEM) were employed to acquire the structural and morphological information of the prepared ZnO based products. Combination of defect structure analysis based on photoluminescence (PL) and electron paramagnetic resonance (EPR) indicated that co-existing oxygen vacancies (V{sub O}) and zinc interstitials (Zn{sub i}) defects are responsible for the observed ferromagnetism in undoped and transition metal (TM) doped ZnO systems. PL analysis demonstrated that undoped ZnO has more donor defects (V{sub O} and Zn{sub i}) which are beneficial for gas response enhancement. Undoped ZnO based sensor exhibited a higher sensor response to NH{sub 3} gas compared to its counterparts owing to high content of donor defects while transition metal doped sensors showed short response and recovery times compared to undoped ZnO.

  14. The influence of the pyrolysis temperature on the electrochemical behavior of carbon-rich SiCN polymer-derived ceramics as anode materials in lithium-ion batteries

    Science.gov (United States)

    Reinold, Lukas Mirko; Yamada, Yuto; Graczyk-Zajac, Magdalena; Munakata, Hirokazu; Kanamura, Kiyoshi; Riedel, Ralf

    2015-05-01

    Within this study we report on the impact of the pyrolysis temperature on the structural and electrochemical properties of the poly(phenylvinylsilylcarbodiimide) derived silicon carbonitride (SiCN) ceramic. Materials pyrolysed at 800 °C and 1300 °C, SiCN 800 and SiCN 1300, are found amorphous. Raman spectroscopy measurements indicate the increase in ordering of the free carbon phase with increasing pyrolysis temperature which leads to lower capacity recovered by SiCN 1300. Significant hysteresis is found for materials pyrolysed at 800 °C during electrochemical lithium insertion/extraction. This feature is attributed to much higher hydrogen content in SiCN 800 sample. An aging of SiCN 800 reflected by a change of elemental composition upon contact to air and a strong film formation are attenuated at a higher pyrolysis temperature. Single particle microelectrode investigation on SiCN 800 and SiCN 1300 clarify different electrochemical behavior of the materials. Much lower charge transfer resistance of SiCN 1300 in comparison to SiCN 800 explains better high currents electrochemical performance. Lithium ions diffusion coefficient Dmin ranges from 3.2 10-9 cm2s-1 to 6.4 10-11 cm2s-1 and is independent on the potential.

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  16. Influence of single and binary doping of strontium and lithium on in vivo biological properties of bioactive glass scaffolds

    Science.gov (United States)

    Khan, Pintu Kumar; Mahato, Arnab; Kundu, Biswanath; Nandi, Samit K.; Mukherjee, Prasenjit; Datta, Someswar; Sarkar, Soumya; Mukherjee, Jayanta; Nath, Shalini; Balla, Vamsi K.; Mandal, Chitra

    2016-01-01

    Effects of strontium and lithium ion doping on the biological properties of bioactive glass (BAG) porous scaffolds have been checked in vitro and in vivo. BAG scaffolds were prepared by conventional glass melting route and subsequently, scaffolds were produced by evaporation of fugitive pore formers. After thorough physico-chemical and in vitro cell characterization, scaffolds were used for pre-clinical study. Soft and hard tissue formation in a rabbit femoral defect model after 2 and 4 months, were assessed using different tools. Histological observations showed excellent osseous tissue formation in Sr and Li + Sr scaffolds and moderate bone regeneration in Li scaffolds. Fluorochrome labeling studies showed wide regions of new bone formation in Sr and Li + Sr doped samples as compared to Li doped samples. SEM revealed abundant collagenous network and minimal or no interfacial gap between bone and implant in Sr and Li + Sr doped samples compared to Li doped samples. Micro CT of Li + Sr samples showed highest degree of peripheral cancellous tissue formation on periphery and cortical tissues inside implanted samples and vascularity among four compositions. Our findings suggest that addition of Sr and/or Li alters physico-chemical properties of BAG and promotes early stage in vivo osseointegration and bone remodeling that may offer new insight in bone tissue engineering. PMID:27604654

  17. Influences of Mg Doping on the Electrochemical Performance of TiO2 Nanodots Based Biosensor Electrodes

    Directory of Open Access Journals (Sweden)

    M. S. H. Al-Furjan

    2014-01-01

    Full Text Available Electrochemical biosensors are essential for health monitors to help in diagnosis and detection of diseases. Enzyme adsorptions on biosensor electrodes and direct electron transfer between them have been recognized as key factors to affect biosensor performance. TiO2 has a good protein adsorption ability and facilitates having more enzyme adsorption and better electron transfer. In this work, Mg ions are introduced into TiO2 nanodots in order to further improve electrode performance because Mg ions are considered to have good affinity with proteins or enzymes. Mg doped TiO2 nanodots on Ti substrates were prepared by spin-coating and calcining. The effects of Mg doping on the nanodots morphology and performance of the electrodes were investigated. The density and size of TiO2 nanodots were obviously changed with Mg doping. The sensitivity of 2% Mg doped TiO2 nanodots based biosensor electrode increased to 1377.64 from 897.8 µA mM−1 cm−2 and its KMapp decreases to 0.83 from 1.27 mM, implying that the enzyme achieves higher catalytic efficiency due to better affinity of the enzyme with the Mg doped TiO2. The present work could provide an alternative to improve biosensor performances.

  18. Research of the influence of radiation of light from emitting diodes in Fricke solution doped with photosensibilizers of low cost

    International Nuclear Information System (INIS)

    Almeida, Mayara G.O. de; Lima, Vanessa L. de; Nascimento, Rizia K. do; Santos, Patricia N.C. dos; Souza, Vivianne L.B. de

    2013-01-01

    This study aims to verify the behavior of FAM dosimeters (Fricke solution doped with methylene blue), FVM (Fricke solution doped with malachite green) and FAT (Fricke solution doped with toluidine blue) after irradiation with LED. Photodynamic therapy (PDT), the newest form of treatment for some types of cancer, is the association of a photosensitizing agent to a light source, in order to induce cancer cell death. PDT does not have a dosimetry and is usually performed with lasers, and photosensitizers imported and expensive. The red and blue were chosen for the experiments. The solution was prepared and Fricke Fricke doped solutions were prepared by adding 100 μg/mL of the photosensitizers. Subsequently, ethanol was added to the dosimeters yielding the FATA , FAME and FVMA. Doped solutions were transferred to test tubes and irradiated in acrylic phantoms. The solutions were irradiated their optical densities measured in a UV - VIS spectrophotometer. Thus, it was found that after irradiation, the dosimeters showed linear behavior showing good correlation coefficients for the samples irradiated with LEDs. The FAME when irradiated with blue light, also showed a linear correlation. However , for FVMA behavior was presented an equation of 2nd degree. Concluding that the LED irradiated dosimeters have shown sensitivity to light so that they can be used for dosimetry in PDT, and the results also show that PDT can be realized with LED photosensitizers and low cost

  19. Coupled influence of noise and damped propagation of impurity on linear and nonlinear polarizabilities of doped quantum dots

    International Nuclear Information System (INIS)

    Ganguly, Jayanta; Ghosh, Manas

    2015-01-01

    Highlights: • Linear and nonlinear polarizabilities of quantum dot are studied. • Quantum dot is doped with a repulsive impurity. • Doped system is subject to Gaussian white noise. • Dopant migrates under damped condition. • Noise-damping coupling affects polarizabilities. - Abstract: We investigate the profiles of diagonal components of static and frequency-dependent linear, first, and second nonlinear polarizabilities of repulsive impurity doped quantum dot. We have considered propagation of dopant within an environment that damps the motion. Simultaneous presence of noise inherent to the system has also been considered. The dopant has a Gaussian potential and noise considered is a Gaussian white noise. The doped system is exposed to an external electric field which could be static or time-dependent. Noise undergoes direct coupling with damping and the noise-damping coupling strength appears to be a crucial parameter that designs the profiles of polarizability components. This happens because the coupling strength modulates the dispersive and asymmetric character of the system. The frequency of external field brings about additional features in the profiles of polarizability components. The present investigation highlights some useful features in the optical properties of doped quantum dots

  20. The pyrolysis of gas condensate at the Shatlyk field

    Energy Technology Data Exchange (ETDEWEB)

    Magaril, R.Z.; Khankuliyev, K.; Kul' zhayev, B.A.; Sergiyenko, S.R.

    1984-01-01

    The continuing growth in industrial demand for lower olefins for the manufacture of polymer materials has necessitated an expansion in the manufacture of ethylene. Gas condensate may serve as a source of ethylene manufacturing. The influence of the contact temperature and time in the pyrolysis of unseparated condensate from the Shatlyk field on the yield of lower olefins was investigated. It was discovered that the total yield of lower olefins (C2-C4) increases with an increase in the pyrolysis temperature, reaching a maximum of 63 to 67 percent by weight at a temperature of 1098 degrees Kelvin and contact time of .5 to .7 seconds, and at 1123 degrees Kelvin and .3 seconds, the maximum ethylene yield (40 percent) was obtained at 1123 degrees Kelvin, and at all previously noted temperatures with a contact time of .9 seconds.

  1. Spray deposited gallium doped tin oxide thinfilm for acetone sensor application

    Science.gov (United States)

    Preethi, M. S.; Bharath, S. P.; Bangera, Kasturi V.

    2018-04-01

    Undoped and gallium doped (1 at.%, 2 at.% and 3 at.%) tin oxide thin films were prepared using spray pyrolysis technique by optimising the deposition conditions such as precursor concentration, substrate temperature and spraying rate. X-ray diffraction analysis revealed formation of tetragonally structured polycrystalline films. The SEM micrographs of Ga doped films showed microstructures. The electrical resistivity of the doped films was found to be more than that of the undoped films. The Ga-doped tin oxide thin films were characterised for gas sensors. 1 at.% Ga doped thin films were found to be better acetone gas sensor, showed 68% sensitivity at 350°C temperature.

  2. Rotor for a pyrolysis centrifuge reactor

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a rotor for a pyrolysis centrifuge reactor, said rotor comprising a rotor body having a longitudinal centre axis, and at least one pivotally mounted blade being adapted to pivot around a pivot axis under rotation of the rotor body around the longitudinal centre axis....... Moreover, the present invention relates to a pyrolysis centrifuge reactor applying such a rotor....

  3. Toxicity of pyrolysis gases from polyether sulfone

    Science.gov (United States)

    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.

  4. Historical Developments of Pyrolysis Reactors : A Review

    NARCIS (Netherlands)

    Garcia-Nunez, J. A.; Pelaez-Samaniego, M.R.; Garcia-Perez, M. E.; Fonts, I.; Abrego, J.; Westerhof, R. J.M.; Garcia Perez, M.

    2017-01-01

    This paper provides a review of pyrolysis technologies, focusing on reactor designs and companies commercializing these technologies. The renewed interest in pyrolysis is driven by the potential to convert lignocellulosic materials into bio-oil and biochar and the use of these intermediates for the

  5. Recovery of plutonium from pyrolysis and incineration residues

    International Nuclear Information System (INIS)

    Isaacs, J.W.; McDonald, L.A.; Roberts, W.G.; Sutcliffe, P.W.; Wilkins, J.D.

    1981-01-01

    The effect of ashes prepared from typical plutonium-handling, glove box, combustible wastes on the dissolution of PuO 2 is described. Synthetic ashes have been prepared by doping inactively-prepared ashes with various plutonium-containing compounds, followed by heating at temperatures in the range 550-1200 0 C. The resulting ashes have been leach-tested in order to provide information on the relationship between leachability, the nature of the ashes, the type of plutonium contamination and temperature of thermal treatment. Optimum temperatures for the recovery of plutonium and for the production of inert ''slag'' -type residues have been identified. A furnace for producing model incinerator ashes and pyrolysis chars under carefully controlled conditions is described. Preliminary results on the leaching of these plutonium-active ashes and chars are discussed. (author)

  6. Influence of Chromium Doping on Electrical and Magnetic Behavior of Nd0.5Sr0.5MnO3 System

    Science.gov (United States)

    Lalitha, G.; Pavan Kumar, N.; Venugopal Reddy, P.

    2018-04-01

    With a view to understand the influence of chromium doping at the Mn site on the electrical and magnetic behavior of the Nd0.5Sr0.5MnO3 manganite system, a series of samples were prepared by the citrate sol-gel route method. The samples were characterized structurally by XRD. A systematic investigation of electrical resistivity over a temperature range 5-300 K was carried out mainly to understand the magneto-transport behavior in these materials. Studies on the variation of magnetization with temperature over a temperature range 80-330 K were undertaken. Investigation of magnetization at different magnetic fields at two different temperatures, viz. 80 and 300 K, was also carried out. The results show that chromium doping gave typical electrical and magnetic properties. It has been concluded that the coexistence of charge ordered and ferromagnetic phases induced by chromium doping plays an important role in the low-temperature behavior of the system.

  7. Fuel production from microwave assisted pyrolysis of coal with carbon surfaces

    International Nuclear Information System (INIS)

    Mushtaq, Faisal; Mat, Ramli; Ani, Farid Nasir

    2016-01-01

    Highlights: • MW heating of coal was carried out with uniformly distributed carbon surfaces. • The effects of carbon loading, MW power and N 2 flow rate were investigated. • Heating profile, pyrolysis products are influenced by the process variables. • Highest coal-tar obtained when final temperature sustained for longer duration. • Coal-tar is mainly composed of aromatics and saturated aliphatics hydrocarbons. - Abstract: In this study, coal solids were subjected to Microwave (MW) pyrolysis conditions. Coconut Activated Carbon (CAC) solids used as a MW absorber was distributed uniformly over coal solids to reduce hotspots. Three process parameters; CAC loading, MW power and N 2 flow rate were studies on pyrolysis heating performance. The highest coal-tar yield of 18.59 wt% was obtained with 600 W, 75 wt% CAC loading and 4 Liter per Minute (LPM) of N 2 flow rate. This improved coal-tar yield is mainly of the fact that higher MW power and CAC loading produced sustained pyrolysis conditions for longer duration for the complete conversion of pyrolysis solids. The coal-tar was composed mainly of aromatics (naphthalenes, benzenes and xylene) and saturated aliphatics (alkanes and alkenes) hydrocarbons. The gas produced from pyrolysis of coal is mainly of H 2 40.23–65.22 vol%.

  8. Biomass pyrolysis/gasification for product gas production: the overall investigation of parametric effects

    International Nuclear Information System (INIS)

    Chen, G.; Andries, J.; Luo, Z.; Spliethoff, H.

    2003-01-01

    The conventional biomass pyrolysis/gasification process for production of medium heating value gas for industrial or civil applications faces two disadvantages, i.e. low gas productivity and the accompanying corrosion of downstream equipment caused by the high content of tar vapour contained in the gas phase. The objective of this paper is to overcome these disadvantages, and therefore, the effects of the operating parameters on biomass pyrolysis are investigated in a laboratory setup based on the principle of keeping the heating value of the gas almost unchanged. The studied parameters include reaction temperature, residence time of volatile phase in the reactor, physico-chemical pretreatment of biomass particles, heating rate of the external heating furnace and improvement of the heat and mass transfer ability of the pyrolysis reactor. The running temperature of a separate cracking reactor and the geometrical configuration of the pyrolysis reactor are also studied. However, due to time limits, different types of catalysts are not used in this work to determine their positive influences on biomass pyrolysis behaviour. The results indicate that product gas production from biomass pyrolysis is sensitive to the operating parameters mentioned above, and the product gas heating value is high, up to 13-15 MJ/N m 3

  9. Evaluating the susceptibility of pyrolysis of monosaccharide, disaccharide, and polysaccharide to CO_2

    International Nuclear Information System (INIS)

    Lee, Jechan; Tsang, Yiu Fai; Oh, Jeong-Ik; Lee, Sang-Ryong; Kwon, Eilhann E.

    2017-01-01

    Highlights: • Two-stage pyrolyzer gives a deep insight into sensitivity of biomass structure to CO_2. • The influence of CO_2 in pyrolysis of biomass occurs selectively. • Hemicellulose and lignin are highly sensitive to CO_2 in pyrolysis. • Thermal cracking of VOCs can be expedited by using CO_2 in pyrolysis. - Abstract: This study is aiming at exploring the genuine role of CO_2 in pyrolysis of lignocellulosic biomass by investigating the susceptibility of pyrolysis of monosaccharide (e.g., xylose and glucose), disaccharide (e.g., sucrose), and polysaccharide (e.g., woody biomass) to CO_2. To do this, the thermal degradation of these four biomass samples was characterized in N_2 and CO_2. The thermal characterization results reveal that the physical aspects of biomass decomposition (i.e., thermal degradation rate and residual mass difference) associated with CO_2 were nearly the same; however, the chemical aspects were significantly different. In other words, CO_2 enhanced thermal cracking of volatile organic compounds (VOCs) generated from thermal degradation of biomass. In addition, our experiment results show that xylose (a major constituent of hemicellulose) and lignin exhibited a high sensitivity to CO_2 in pyrolysis.

  10. Catalytic pyrolysis of microalgae to high-quality liquid bio-fuels

    International Nuclear Information System (INIS)

    Babich, I.V.; Hulst, M. van der; Lefferts, L.; Moulijn, J.A.; O'Connor, P.; Seshan, K.

    2011-01-01

    The pyrolytic conversion of chlorella algae to liquid fuel precursor in presence of a catalyst (Na 2 CO 3 ) has been studied. Thermal decomposition studies of the algae samples were performed using TGA coupled with MS. Liquid oil samples were collected from pyrolysis experiments in a fixed-bed reactor and characterized for water content and heating value. The oil composition was analyzed by GC-MS. Pretreatment of chlorella with Na 2 CO 3 influences the primary conversion of chlorella by shifting the decomposition temperature to a lower value. In the presence of Na 2 CO 3 , gas yield increased and liquid yield decreased when compared with non-catalytic pyrolysis at the same temperatures. However, pyrolysis oil from catalytic runs carries higher heating value and lower acidity. Lower content of acids in the bio-oil, higher aromatics, combined with higher heating value show promise for production of high-quality bio-oil from algae via catalytic pyrolysis, resulting in energy recovery in bio-oil of 40%. -- Highlights: → The pyrolytic catalytic conversion of chlorella algae to liquid fuel precursor. → Na 2 CO 3 as a catalyst for the primary conversion of chlorella. → Pyrolysis oil from catalytic runs carries higher heating value and lower acidity. → High-quality bio-oil from algae via catalytic pyrolysis with energy recovery in bio-oil of 40%.

  11. Pyrolysis behavior of different type of materials contained in the rejects of packaging waste sorting plants.

    Science.gov (United States)

    Adrados, A; De Marco, I; Lopez-Urionabarrenechea, A; Caballero, B M; Laresgoiti, M F

    2013-01-01

    In this paper rejected streams coming from a waste packaging material recovery facility have been characterized and separated into families of products of similar nature in order to determine the influence of different types of ingredients in the products obtained in the pyrolysis process. The pyrolysis experiments have been carried out in a non-stirred batch 3.5 dm(3) reactor, swept with 1 L min(-1) N(2), at 500°C for 30 min. Pyrolysis liquids are composed of an organic phase and an aqueous phase. The aqueous phase is greater as higher is the cellulosic material content in the sample. The organic phase contains valuable chemicals as styrene, ethylbenzene and toluene, and has high heating value (HHV) (33-40 MJ kg(-1)). Therefore they could be used as alternative fuels for heat and power generation and as a source of valuable chemicals. Pyrolysis gases are mainly composed of hydrocarbons but contain high amounts of CO and CO(2); their HHV is in the range of 18-46 MJ kg(-1). The amount of COCO(2) increases, and consequently HHV decreases as higher is the cellulosic content of the waste. Pyrolysis solids are mainly composed of inorganics and char formed in the process. The cellulosic materials lower the quality of the pyrolysis liquids and gases, and increase the production of char. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Discernment of synergism in pyrolysis of biomass blends using thermogravimetric analysis.

    Science.gov (United States)

    Mallick, Debarshi; Poddar, Maneesh Kumar; Mahanta, Pinakeswar; Moholkar, Vijayanand S

    2018-04-12

    This study reports pyrolysis kinetics of biomass blends using isoconversional methods, viz. Friedman, FWO and KAS. Blends of three biomasses, viz. saw dust, bamboo dust and rice husk, were used. Extractives and volatiles in biomass and minerals in ash had marked influence on enhancement of reaction kinetics during co-pyrolysis, as indicated by reduction in activation energy and increase in decomposition intensity. Pyrolysis kinetics of saw dust and rice husk accelerated (positive synergy), while that of bamboo dust decelerated after blending (negative synergy). Predominant reaction mechanism of all biomass blends was 3-D diffusion in lower conversion range (α ≤ 0.5), while for α ≥ 0.5 pyrolysis followed random nucleation (or nucleation and growth mechanism). Higher reaction order for pyrolysis of blends of rice husk with saw dust and bamboo dust was attributed to catalytic effect of minerals in ash. Positive ΔH and ΔG was obtained for pyrolysis of all biomass blends. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Pyrolysis process of agricultural waste using CO2 for waste management, energy recovery, and biochar fabrication

    International Nuclear Information System (INIS)

    Lee, Jechan; Yang, Xiao; Cho, Seong-Heon; Kim, Jae-Kon; Lee, Sang Soo; Tsang, Daniel C.W.; Ok, Yong Sik; Kwon, Eilhann E.

    2017-01-01

    Highlights: • CO 2 reacts with VOCs enhancing syngas generation from pyrolysis of biomass. • CO 2 reduces tar formation by expediting thermal cracking of VOCs. • Properties of biochar can be easily modified using CO 2 as a pyrolysis agent. • A detailed mass balance for pyrolysis of red pepper stalk was provided. • Energy saving can be expected in pyrolysis of biomass using CO 2 . - Abstract: This study focused on the mechanistic understanding of CO 2 in pyrolysis process of agricultural waste to achieve waste management, energy recovery, and biochar fabrication. In order to scrutinize the genuine role of CO 2 in the biomass pyrolysis, all pyrogenic products such as syngas, pyrolytic oil (i.e., tar), and biochar generated from pyrolysis of red pepper stalk in N 2 and CO 2 were characterized. Thermo-gravimetric analysis confirmed that during the thermolysis of red pepper stalk, the magnitude of exothermic reaction in CO 2 from 220 to 400 °C was substantially different from that in N 2 , resulting in the different extents of carbonization. The physico-chemical properties of biochar produced in CO 2 were varied compared to biochar produced in N 2 . For example, the surface area of biochar produced in CO 2 was increased from 32.46 to 109.15 m 2 g −1 . This study validates the role of CO 2 not only as expediting agent for the thermal cracking of volatile organic carbons (VOCs) but also as reacting agent with VOCs. This genuine influence of CO 2 in pyrolysis of red pepper stalk led to enhanced generation of syngas, which consequently reduced tar production because VOCs evolving from devolatilization of biomass served as substrates for syngas via reaction between CO 2 and VOCs. The enhanced generation of CO reached up to 3000 and 6000% at 600 and 690 °C, respectively, whereas 33.8% tar reduction in CO 2 was identified at 600 °C.

  14. Influence of Fe-doping on the structural, optical and magnetic properties of ZnO nanoparticles

    International Nuclear Information System (INIS)

    Liu Changzhen; Meng Dawei; Pang Haixia; Wu Xiuling; Xie Jing; Yu Xiaohong; Chen Long; Liu Xiaoyang

    2012-01-01

    Zn 1–x Fe x O (x=0–0.05) nanoparticles were synthesized without a catalyst by a two-step method. Fe was doped into ZnO by a source of metallic Fe sheets in a solid–liquid system at 80 °C, and the Zn 1−x Fe x O nanoparticles were obtained by annealing at 300 °C. X-ray diffraction, X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy were used to characterize the structural properties of the as-grown Zn 1−x Fe x O. The optical properties were determined by Infrared and Ultraviolet–visible spectroscopy. The results confirm that the crystallinity of the ZnO is deteriorated due to Fe-doping. XPS results show that there is a mixture of Fe 0+ and the Fe 3+ in the representative Zn 0.95 Fe 0.05 O sample. The optical band gap of Zn 1−x Fe x O is enhanced with increasing of Fe-doping. Room temperature ferromagnetism was observed in all the Fe-doped ZnO samples. - Highlights: ► Zn 1−x Fe x O nanoparticles were synthesized with a simple two-step method. ► The Zn 1−x Fe x O predecessors were synthesized at a low temperature. ► Fe element was readily doped from the source of metallic Fe sheet. ► All the Fe doping ZnO samples have room temperature ferromagnetism. ► The structural and properties of the Zn 1−x Fe x O are regular with different x.

  15. Influence of the disorder in doped germanium changed by compensation on the critical indices of the metal-insulator transition

    International Nuclear Information System (INIS)

    Rentzsch, R.; Reich, Ch.; Ionov, A.N.; Ginodman, V.; Slimak, I.; Fozooni, P.; Lea, M.J.

    1999-01-01

    We present a critical review of the present status of the critical exponent puzzle of the metal-insulator transition of doped semiconductors with the emphasis on the role of meso- and macroscopy inhomogeneity caused by the disorder of acceptors and donors in the crystals. By using the isotopic and engineering and the neutron transmutation doping of germanium we found for low compensations (at K = 1.4 and 12%) that the critical exponents of the localization length and the dielectric constant are nearly ν = 1/2 and ξ = 1, which double for medium compensations (at K = 39 and 54%) to ν 1 and ξ = 2, respectively

  16. The influence of alizarin and fluorescein on the photoactivity of Ni, Pt and Ru-doped TiO2 layers

    International Nuclear Information System (INIS)

    Rosu, Marcela-Corina; Suciu, Ramona-Crina; Lazar, Mihaela D.; Bratu, I.

    2013-01-01

    Highlights: ► The Ni, Pt, Ru-doped TiO 2 materials and sensitized with alizarin and fluorescein dyes were prepared by wet chemical route. ► The samples were characterized by: UV–vis spectroscopy, spectrofluorimetry, FT/IR spectroscopy and microscopy, X-ray diffraction and N 2 physisorption measurements. ► A combined influence of the dopants and dyes was observed, leading to a beneficial effect to TiO 2 photoactivity. -- Abstract: The doping with different metal ions and sensitization with organic compounds are two well known methods used to improve the photoactivity of TiO 2 . In this respect, the metallic ions-doped TiO 2 samples were prepared by embedding Ni, Pt and Ru ions into TiO 2 crystalline network and then, each sample was sensitized with alizarin and fluorescein dyes. The qualitative evaluation of prepared TiO 2 -based materials was made by: UV–vis spectroscopy, spectrofluorimetry, FT/IR spectroscopy and microscopy, X-ray diffraction and N 2 physisorption measurements. The optoelectronic properties investigated by UV–vis spectroscopy show that the optical response of Ni-doped TiO 2 layer shifts to visible. The X-ray spectra do not show peaks of nickel, platinum and ruthenium oxide crystals or pure metals. The FT/IR spectra proved the presence of dye molecules adsorbed on titania nanoparticles surface. These results demonstrated that the studied dopants and dyes have potential to promote modified TiO 2 -based materials as good candidates to be used in photolectrocatalytic processes

  17. The influence of alizarin and fluorescein on the photoactivity of Ni, Pt and Ru-doped TiO{sub 2} layers

    Energy Technology Data Exchange (ETDEWEB)

    Rosu, Marcela-Corina, E-mail: marcela.rosu@itim-cj.ro [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath Street, 400293, Cluj-Napoca (Romania); Suciu, Ramona-Crina; Lazar, Mihaela D.; Bratu, I. [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath Street, 400293, Cluj-Napoca (Romania)

    2013-04-20

    Highlights: ► The Ni, Pt, Ru-doped TiO{sub 2} materials and sensitized with alizarin and fluorescein dyes were prepared by wet chemical route. ► The samples were characterized by: UV–vis spectroscopy, spectrofluorimetry, FT/IR spectroscopy and microscopy, X-ray diffraction and N{sub 2} physisorption measurements. ► A combined influence of the dopants and dyes was observed, leading to a beneficial effect to TiO{sub 2} photoactivity. -- Abstract: The doping with different metal ions and sensitization with organic compounds are two well known methods used to improve the photoactivity of TiO{sub 2}. In this respect, the metallic ions-doped TiO{sub 2} samples were prepared by embedding Ni, Pt and Ru ions into TiO{sub 2} crystalline network and then, each sample was sensitized with alizarin and fluorescein dyes. The qualitative evaluation of prepared TiO{sub 2}-based materials was made by: UV–vis spectroscopy, spectrofluorimetry, FT/IR spectroscopy and microscopy, X-ray diffraction and N{sub 2} physisorption measurements. The optoelectronic properties investigated by UV–vis spectroscopy show that the optical response of Ni-doped TiO{sub 2} layer shifts to visible. The X-ray spectra do not show peaks of nickel, platinum and ruthenium oxide crystals or pure metals. The FT/IR spectra proved the presence of dye molecules adsorbed on titania nanoparticles surface. These results demonstrated that the studied dopants and dyes have potential to promote modified TiO{sub 2}-based materials as good candidates to be used in photolectrocatalytic processes.

  18. Influence of temperature on the photodegradation process using Ag-doped TiO2nanostructures: Negative impact with the nanofibers

    DEFF Research Database (Denmark)

    Barakata, Nasser A.M.; Kanjwal, Muzafar Ahmad; Chronakis, Ioannis S.

    In this study, the influence of the temperature on the photodegradation process using Ag-doped TiO2 nanostructures was investigated. Two morphologies were used; nanoparticles and nanofibers. The nanofibers were synthesized by electrospinning of a sol–gel consisting of titanium isopropoxide, silver...... nitrate and poly(vinyl acetate). The silver nitrate amount was changed to produce nanofibers having different silver contents. Typically, sol–gels containing 0.5, 1.0, 1.5, 2.0 and 2.5 wt% silver nitrate were utilized. Calcination of the electrospun mats at 700 °C led to produce well morphology Ag...

  19. Electrolyte influence on the Cu nanoparticles electrodeposition onto boron doped diamond electrode; Influencia do eletrolito na eletrodeposicao de nanoparticulas de Cu sobre eletrodo de diamante dopado com boro

    Energy Technology Data Exchange (ETDEWEB)

    Matsushima, Jorge Tadao; Santos, Laura Camila Diniz; Couto, Andrea Boldarini; Baldan, Mauricio Ribeiro; Ferreira, Neidenei Gomes [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil)

    2012-07-01

    This paper presents the electrolyte influence on deposition and dissolution processes of Cu nanoparticles on boron doped diamond electrodes (DDB). Morphological, structural and electrochemical analysis showed BDD films with good reproducibility, quality and reversible in a specific redox system. Electrodeposition of Cu nanoparticles on DDB electrodes in three different solutions was influenced by pH and ionic strength of the electrolytic medium. Analyzing the process as function of the scan rate, it was verified a better efficiency in 0,5 mol L{sup -1} Na{sub 2}SO{sub 4} solution. Under the influence of the pH and ionic strength, Cu nanoparticles on DDB may be obtained with different morphologies and it was important for defining the desired properties. (author)

  20. Influence of sulfidation treatment on the structure and tribological properties of nitrogen-doped diamond-like carbon films

    International Nuclear Information System (INIS)

    Zeng Qunfeng; Dong Guangneng; Xie Youbai

    2008-01-01

    The nitrogen-doped diamond-like carbon (DLC) films were deposited on high speed steel (HSS) substrates in the direct current unbalanced magnetron sputtering system. Sulphurized layer was formed on the surface of DLC films by means of liquid sulfidation in the intermixture of urea and thiourea solution in order to improve the tribological properties of DLC films. The influence of sulfidation treatment on the structure and tribological properties of DLC films was investigated in this work. The structure and wear surface morphology of DLC films were analyzed by Raman spectroscopy, XPS and SEM, respectively. It reveals that the treated films are smooth and uniform; and sulfur atoms are bonded chemically. The treated films have broader distribution of Raman spectra in the range of 1000-1800 cm -1 and higher I D /I G ratio than the untreated films as a result of the appearance of the crystalline graphite structure after the sulfidation treatment. It is showed that the sp 2 relative content increase in the treated films from the XPS measurement. The Raman results are consistent with the XPS results. The tribological properties of DLC films were investigated using a ball-on-disk rotating friction and wear tester under dry friction conditions. It is found that the sulfidation concentration plays an important part in the tribological properties of the treated DLC films. The results showed the treated films with low sulfidation concentration have a lower friction coefficient (0.1) than the treated films with high sulfidation concentration (0.26) and the untreated films (0.27) under the same friction testing conditions, which can be attributed to both the presence of sulfur-containing materials and the forming of the mechanical alloyed layer on the wear surface. Adding the dry nitrogen to the sliding surface in the testing system helps the friction coefficient of the treated films with low sulfidation concentration to decrease to 0.04 further in this work. On the basis of the

  1. Carbamazepine degradation using a N-doped TiO_2 coated photocatalytic membrane reactor: Influence of physical parameters

    International Nuclear Information System (INIS)

    Horovitz, Inna; Avisar, Dror; Baker, Mark A.; Grilli, Rossana; Lozzi, Luca; Di Camillo, Daniela; Mamane, Hadas

    2016-01-01

    Highlights: • UV–vis N-doped TiO_2 was deposited by sol-gel onto Al_2O_3 microfiltration membranes. • Coating decreased permeability by 50 and 12% for 200- and 800-nm Al_2O_3 membranes. • Flow through membrane results in higher reaction rates compared to flow on top. • Higher vis photocatalytic activity for N-doped TiO_2 vs. non-doped TiO_2 membranes. • Mass transfer is a critical parameter for the design of immobilized PMR. - Abstract: Commercial α-Al_2O_3 photocatalytic membranes with a pore size of 200 and 800-nm were coated with N-doped TiO_2 photocatalytic film using a sol-gel technique for concurrent bottom-up filtration and photocatalytic oxidation. X-ray diffraction confirmed that the deposited N-doped TiO_2 films are in the form of anatase with 78–84% coverage of the membrane surface. The concentration of N found by X-ray photoelectron spectroscopy was in the range of 0.3–0.9 atomic percentage. Membrane permeability after coating decreased by 50% and 12% for the 200- and 800-nm membrane substrates, respectively. The impact of operational parameters on the photocatalytic activity (PCA) of the N-doped TiO_2-coated membranes was examined in a laboratory flow cell based on degradation of the model micropollutant carbamazepine, using a solar simulator as the light source. The significant gap in degradation rate between flow through the membrane and flow on the surface of the membrane was attributed both to the hydraulic effect and in-pore PCA. N-doped TiO_2-coated membranes showed enhanced activity for UV wavelengths, in addition to activity under visible light. Experiments of PCA under varying flow rates concluded that the process is in the mass-transfer control regime. Carbamazepine removal rate increased with temperature, despite the decrease in dissolved oxygen concentration.

  2. Carbamazepine degradation using a N-doped TiO{sub 2} coated photocatalytic membrane reactor: Influence of physical parameters

    Energy Technology Data Exchange (ETDEWEB)

    Horovitz, Inna [School of Mechanical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 69978 (Israel); The Hydro-Chemistry Laboratory, Faculty of Geography and the Environment, Tel Aviv University, Tel Aviv 69978 (Israel); Avisar, Dror [The Hydro-Chemistry Laboratory, Faculty of Geography and the Environment, Tel Aviv University, Tel Aviv 69978 (Israel); Baker, Mark A.; Grilli, Rossana [The Surface Analysis Laboratory, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, Surrey, GU2 7XH (United Kingdom); Lozzi, Luca; Di Camillo, Daniela [Department of Physical and Chemical Sciences, University of L' Aquila, Via Vetoio, I-67100 L' Aquila (Italy); Mamane, Hadas, E-mail: hadasmg@post.tau.ac.il [School of Mechanical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 69978 (Israel)

    2016-06-05

    Highlights: • UV–vis N-doped TiO{sub 2} was deposited by sol-gel onto Al{sub 2}O{sub 3} microfiltration membranes. • Coating decreased permeability by 50 and 12% for 200- and 800-nm Al{sub 2}O{sub 3} membranes. • Flow through membrane results in higher reaction rates compared to flow on top. • Higher vis photocatalytic activity for N-doped TiO{sub 2} vs. non-doped TiO{sub 2} membranes. • Mass transfer is a critical parameter for the design of immobilized PMR. - Abstract: Commercial α-Al{sub 2}O{sub 3} photocatalytic membranes with a pore size of 200 and 800-nm were coated with N-doped TiO{sub 2} photocatalytic film using a sol-gel technique for concurrent bottom-up filtration and photocatalytic oxidation. X-ray diffraction confirmed that the deposited N-doped TiO{sub 2} films are in the form of anatase with 78–84% coverage of the membrane surface. The concentration of N found by X-ray photoelectron spectroscopy was in the range of 0.3–0.9 atomic percentage. Membrane permeability after coating decreased by 50% and 12% for the 200- and 800-nm membrane substrates, respectively. The impact of operational parameters on the photocatalytic activity (PCA) of the N-doped TiO{sub 2}-coated membranes was examined in a laboratory flow cell based on degradation of the model micropollutant carbamazepine, using a solar simulator as the light source. The significant gap in degradation rate between flow through the membrane and flow on the surface of the membrane was attributed both to the hydraulic effect and in-pore PCA. N-doped TiO{sub 2}-coated membranes showed enhanced activity for UV wavelengths, in addition to activity under visible light. Experiments of PCA under varying flow rates concluded that the process is in the mass-transfer control regime. Carbamazepine removal rate increased with temperature, despite the decrease in dissolved oxygen concentration.

  3. Characterization of doped PEDOT: PSS and its influence on the performance and degradation of organic solar cells

    International Nuclear Information System (INIS)

    Singh, Vinamrita; Sharma, Vishal; Tandon, R P; Arora, Swati; Arora, Manoj

    2014-01-01

    The present work is a detailed study of the optical, morphological and electrical properties of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate), PEDOT:PSS, films doped with ethylene glycol (EG) and multi-walled carbon nanotubes (MWCNT). The conductivity of PEDOT:PSS films doped with EG and MWCNT is higher than pristine PEDOT:PSS film. The optical transparency of PEDOT:PSS film decreases insignificantly after addition of MWCNT and EG. The films were further studied using atomic force microscopy,  x-ray diffraction, Raman spectroscopy and Kelvin probe work function measurement, after which films of PEDOT:PSS with EG and MWCNT were optimized for the fabrication of solar cells. The optimized film was used as a hole extracting layer in a typical ITO/PEDOT:PSS/P3HT:PCBM/Al solar cell. The suitable concentration for an optimized film was found to be 4% MWCNT and 1:4 ratio of EG to PEDOT:PSS. The performance of the device with doped PEDOT:PSS was found to improve in terms of short circuit current density (J SC ) and efficiency (η). The solar cell with a doped PEDOT:PSS layer showed higher J SC  and η due to the increase in the interchains among PEDOT chains along with the introduction of MWCNT channels in PEDOT:PSS matrix. The degradation behavior of the cells was studied and it was found that both pristine and doped PEDOT:PSS cells showed similar trends of degradation. The performance degradation with time was also studied under variable environmental conditions, which showed different aging rates for the two devices. (paper)

  4. Influence of SrF_2-doping in AlN ceramics on scintillation and dosimeter properties

    International Nuclear Information System (INIS)

    Kojima, Kaori; Okada, Go; Fukuda, Kentaro; Yanagida, Takayuki

    2016-01-01

    In this study, we synthesized undoped AlN and SrF_2-doped AlN (AlN-SrF_2) ceramics by Spark Plasma Sintering (SPS), and we characterized their optical, scintillation and dosimeter properties. The prepared undoped AlN ceramic had gray color and visually non-transparent whereas, with an addition of SrF_2, the transparency improved and became translucent. The measured in-line transmittance was approximately 0.2% at wavelengths longer than 500 nm. While the addition of SrF_2 decreased the scintillation intensity, the decay time was significantly fastened, which is a great advantage for fast photon counting-based measurements. Both the thermally-stimulated luminescence (TSL) and optically-stimulated luminescence (OSL) showed good linear response from the milli-gray range to over 10 Gy. The sensitivity seems to decrease by an addition of SrF_2 as it suppresses structural defect centers which are responsible for dosimeter properties. However, the main TSL glow peak position shifts to higher temperature with the addition of SrF_2, which indicates that inclusion of SrF_2 improves the TSL signal stability. - Highlights: • We synthesized undoped and SrF_2-doped AlN ceramics by Spark Plasma Sintering. • We evaluated scintillator and dosimeter properties of undoped and SrF_2-doped AlN. • By doping with SrF_2, the decay time is shortened. • By doping with SrF_2, the stability of TSL and OSL is improved.

  5. Synthesis of carbon nanomaterials from different pyrolysis techniques: a review

    Science.gov (United States)

    Umer Zahid, Muhammad; Pervaiz, Erum; Hussain, Arshad; Shahzad, Muhammad Imran; Niazi, Muhammad Bilal Khan

    2018-05-01

    In the current age, the significance of carbon-based nanomaterials for many applications has made the efforts for the facile synthesis methods from abundantly available wastes in a cost-effective way. Pyrolysis in a broad spectrum is commonly employed for the synthesis of carbon nanostructures by thermally treating the organic waste. The mechanism of growth of the nanoparticles determines the functional distribution of nanoparticles based on the growing size, medium, and physio-chemical properties. Carbon nanomaterial’s growth is a complicated process which is profoundly influenced by temperature, catalyst, and type of precursor. Nowadays, significant progress has been made in improving nanomaterial’s growth techniques, opening new paths for commercial production of carbon-based nanomaterials. The most promising are the methods involving hydrocarbon-rich organic waste as the feed source. In this review, synthesis of carbon-based nanomaterials, specifically carbon nanotubes (CNTs), Carbon nanofibers (CNFs) and Graphene (G) are discussed by different pyrolysis techniques. Furthermore, the review explores recent advancements made in the context of pyrolysis.

  6. Pyrolysis behavior of different type of materials contained in the rejects of packaging waste sorting plants

    Energy Technology Data Exchange (ETDEWEB)

    Adrados, A., E-mail: aitziber.adrados@ehu.es [Chemical and Environmental Engineering Department, School of Engineering of Bilbao, Alameda. Urquijo s/n, 48013 Bilbao (Spain); De Marco, I.; Lopez-Urionabarrenechea, A.; Caballero, B.M.; Laresgoiti, M.F. [Chemical and Environmental Engineering Department, School of Engineering of Bilbao, Alameda. Urquijo s/n, 48013 Bilbao (Spain)

    2013-01-15

    Highlights: Black-Right-Pointing-Pointer Study of the influence of materials in the pyrolysis of real plastic waste samples. Black-Right-Pointing-Pointer Inorganic compounds remain unaltered. Black-Right-Pointing-Pointer Cellulosic components give rise to an increase in char formation. Black-Right-Pointing-Pointer Cellulosic components promote the production of aqueous phase. Black-Right-Pointing-Pointer Cellulosic components increase CO and CO{sub 2} contents in the gases. - Abstract: In this paper rejected streams coming from a waste packaging material recovery facility have been characterized and separated into families of products of similar nature in order to determine the influence of different types of ingredients in the products obtained in the pyrolysis process. The pyrolysis experiments have been carried out in a non-stirred batch 3.5 dm{sup 3} reactor, swept with 1 L min{sup -1} N{sub 2}, at 500 Degree-Sign C for 30 min. Pyrolysis liquids are composed of an organic phase and an aqueous phase. The aqueous phase is greater as higher is the cellulosic material content in the sample. The organic phase contains valuable chemicals as styrene, ethylbenzene and toluene, and has high heating value (HHV) (33-40 MJ kg{sup -1}). Therefore they could be used as alternative fuels for heat and power generation and as a source of valuable chemicals. Pyrolysis gases are mainly composed of hydrocarbons but contain high amounts of CO and CO{sub 2}; their HHV is in the range of 18-46 MJ kg{sup -1}. The amount of CO-CO{sub 2} increases, and consequently HHV decreases as higher is the cellulosic content of the waste. Pyrolysis solids are mainly composed of inorganics and char formed in the process. The cellulosic materials lower the quality of the pyrolysis liquids and gases, and increase the production of char.

  7. Influence of boron concentration on growth characteristic and electro-catalytic performance of boron-doped diamond electrodes prepared by direct current plasma chemical vapor deposition

    International Nuclear Information System (INIS)

    Feng Yujie; Lv Jiangwei; Liu Junfeng; Gao Na; Peng Hongyan; Chen Yuqiang

    2011-01-01

    A series of boron-doped diamond (BDD) electrodes were prepared by direct current plasma chemical vapor deposition (DC-PCVD) with different compositions of CH 4 /H 2 /B(OCH 3 ) 3 gas mixture. A maximum growth rate of 0.65 mg cm -2 h -1 was obtained with CH 4 /H 2 /B(OCH 3 ) 3 radio of 4/190/10 and this growth condition was also a turning point for discharge plasma stability which arose from the addition of B(OCH 3 ) 3 that changed electron energy distribution and influenced the plasma reaction. The surface coating structure and electro-catalytic performance of the BDD electrodes were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, Hall test, and electrochemical measurement and electro-catalytic oxidation in phenol solution. It is suggested that the boron doping level and the thermal stress in the films are the main factors affecting the electro-catalytic characteristics of the electrodes. Low boron doping level with CH 4 /H 2 /B(OCH 3 ) 3 ratio of 4/199/1 decreased the films electrical conductivity and its electro-catalytic activity. When the carrier concentration in the films reached around 10 20 cm -3 with CH 4 /H 2 /B(OCH 3 ) 3 ratio over a range of 4/195/5-4/185/15, the thermal stress in the films was the key reason that influenced the electro-catalytic activity of the electrodes for its effect on diamond lattice expansion. Therefore, the BDD electrode with modest CH 4 /H 2 /B(OCH 3 ) 3 ratio of 4/190/10 possessed the best phenol removal efficiency.

  8. Pyrolysis of spent ion-exchanger resins

    International Nuclear Information System (INIS)

    Slametschka, Rainer; Braehler, Georg

    2012-01-01

    Initial tests have shown that ion exchangers (IEX) can be decomposed by pyrolysis with very good results, yielding an inert and chemically resistant product. No additives are necessary. The main constituent of the product, the pyrolysis residues or ash, is carbon. It has been discovered that the entire radioactive inventory remains in the pyrolysis residues during pyrolysis of the IEX. This is achieved by relatively low process temperatures that prevent highly volatile nuclides such as the caesium nuclides from passing into the gaseous phase. Sintered metal filters in pyrolysis plant ensure that even the radioactivity bonded to the dust remains in the pyrolysis residues. In addition to the radionuclides, the main constituents of the residue are carbon from the original polystyrene matrix and sulphur from the functional groups. The pyrolysis residues form a flowable solid material and not a melt. It is thus easy to handle and can be compacted or cemented, depending on the requirements for interim and permanent storage. Any further constituents such as inorganic filter materials or even other organic materials do not interfere with the process, they are dried, calcined or also pyrolysed. (orig.)

  9. Influences of oxygen gas flow rate on electrical properties of Ga-doped ZnO thin films deposited on glass and sapphire substrates

    International Nuclear Information System (INIS)

    Makino, Hisao; Song, Huaping; Yamamoto, Tetsuya

    2014-01-01

    The Ga-doped ZnO (GZO) films deposited on glass and c-plane sapphire substrates have been comparatively studied in order to explore the role of grain boundaries in electrical properties. The influences of oxygen gas flow rates (OFRs) during the deposition by ion-plating were examined. The dependences of carrier concentration, lattice parameters, and characteristic of thermal desorption of Zn on the OFR showed common features between glass and sapphire substrates, however, the Hall mobility showed different behavior. The Hall mobility of GZO films on glass increased with increasing OFR of up to 15 sccm, and decreased with further increasing OFR. On the other hand, the Hall mobility of GZO films on c-sapphire increased for up to 25 sccm. The role of grain boundary in polycrystalline GZO films has been discussed. - Highlights: • Ga-doped ZnO films were deposited on glass and c-sapphire by ion-plating. • The epitaxial growth on c-sapphire was confirmed by X-ray diffraction. • Dependence of Hall mobility showed different tendency between glass and sapphire. • Grain boundaries influence transport properties at high O 2 gas flow rate

  10. Influence of Nitrogen Doping on Device Operation for TiO2-Based Solid-State Dye-Sensitized Solar Cells: Photo-Physics from Materials to Devices

    Directory of Open Access Journals (Sweden)

    Jin Wang

    2016-02-01

    Full Text Available Solid-state dye-sensitized solar cells (ssDSSC constitute a major approach to photovoltaic energy conversion with efficiencies over 8% reported thanks to the rational design of efficient porous metal oxide electrodes, organic chromophores, and hole transporters. Among the various strategies used to push the performance ahead, doping of the nanocrystalline titanium dioxide (TiO2 electrode is regularly proposed to extend the photo-activity of the materials into the visible range. However, although various beneficial effects for device performance have been observed in the literature, they remain strongly dependent on the method used for the production of the metal oxide, and the influence of nitrogen atoms on charge kinetics remains unclear. To shed light on this open question, we synthesized a set of N-doped TiO2 nanopowders with various nitrogen contents, and exploited them for the fabrication of ssDSSC. Particularly, we carefully analyzed the localization of the dopants using X-ray photo-electron spectroscopy (XPS and monitored their influence on the photo-induced charge kinetics probed both at the material and device levels. We demonstrate a strong correlation between the kinetics of photo-induced charge carriers probed both at the level of the nanopowders and at the level of working solar cells, illustrating a direct transposition of the photo-physic properties from materials to devices.

  11. Molybdenum Doped SnO2 Thin Films as a Methanol Vapor Sensor

    Directory of Open Access Journals (Sweden)

    Patil Shriram B.

    2013-02-01

    Full Text Available The molybdenum doped SnO2 thin films were synthesized by conventional spray pyrolysis route and has been investigated for the methanol vapor sensing. The structural and elemental composition analysis of thin films was carried out by X- ray diffraction and Scanning Electron Microscopy (SEM and Energy Dispersive X-ray spectroscopy (EDAX.The XRD spectrum revealed that the thin films have the polycrystalline nature with a mixed phase comprising of SnO2 and MoO3. The scanning Electron Microscopy (SEM clears that the surface morphology observed to be granular, uniformly covering the entire surface area of the thin film. The methanol vapor sensing studies were performed in dry air at the different temperatures. The influence of the concentration of Molybdenum and operating temperature on the sensor performance has been investigated.

  12. Physicochemical characterization of sludge obtained in a UASB reactor: influence on the energetic utilization in the pyrolysis process; Caracterizacao fisico-quimica de lodo obtido em um reator UASB: influencia no aproveitamento energetico em processo de pirolise

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Murillo Barros de [Universidade Federal do Tocantins (UFT), Palmas, TO (Brazil)], Email: murillopur@yahoo.com.br; Vieira, Glaucia Eliza Gama; Cardoso, Aderlanio da Silva; Silveira, Dyego Amaral; Figueiredo, Radson Lima [Universidade Federal do Tocantins (LEDBIO/UFT), Palmas, TO (Brazil). Lab. de Ensaios e Desenvolvimento de Biomassas e Biocombustiveis

    2010-07-01

    In biological treatment processes of domestic sewer it leaves of the organic matter is converted and another is absorbed being part of the microbial biomass denominated generic of mud biological or secondary composed mainly of biological solids, and that for that reason can also be denominated of sewage sludge. To give a maintainable final destiny for that residue has been one of the great challenges of the sanitation in the last years. Great part of that material is destined unproductive some are incinerated, others are disposed in sanitary embankments. This work had as objective the physiochemical characterization of the digested sludge, virgin and free from oxide of calcium (CaO), produced in the reactor UASB, of ETE Vila Uniao located in the city of Palmas-TO, for the destination as raw material for energy use in pyrolysis process. The collected sample was taken drought and stabilized to be analyzed at the laboratory LEDBIO/UFT where they were studied the particle, tenor of ashes, humidity and volatile density and sequential extraction for soxhlet. Found in the biomass loud tenor of volatile (56,72%), carbon fastens low (5,21%) and a considerable tenor of ashes (32,78%), what suggests that that sludge, in agreement with the comparisons of the literature, can obtain good incomes in pyrolysis process, especially incomes in bio-oil and coal. (author)

  13. Effect of pyrolysis pressure and heating rate on radiata pine char structure and apparent gasification reactivity

    Energy Technology Data Exchange (ETDEWEB)

    E. Cetin; R. Gupta; B. Moghtaderi [University of Newcastle, Callaghan, NSW (Australia). Discipline of Chemical Engineering, Faculty of Engineering and Built Environment, School of Engineering

    2005-07-01

    The knowledge of biomass char gasification kinetics has considerable importance in the design of advanced biomass gasifiers, some of which operate at high pressure. The char gasification kinetics themselves are influenced by char structure. In this study, the effects of pyrolysis pressure and heating rate on the char structure were investigated using scanning electron microscopy (SEM) analysis, digital cinematography, and surface area analysis. Char samples were prepared at pressures between 1 and 20 bar, temperatures ranging from 800 to 1000{degree}C, and heating rates between 20 and 500{degree}C/s. Our results indicate that pyrolysis conditions have a notable impact on the biomass char morphology. Pyrolysis pressure, in particular, was found to influence the size and the shape of char particles while high heating rates led to plastic deformation of particles (i.e. melting) resulting in smooth surfaces and large cavities. The global gasification reactivities of char samples were also determined using thermogravimetric analysis (TGA) technique. Char reactivities were found to increase with increasing pyrolysis heating rates and decreasing pyrolysis pressure. 22 refs., 8 figs., 2 tabs.

  14. Identifying the influence of the intrinsic defects in Gd-doped ZnO thin-films

    KAUST Repository

    Flemban, Tahani H.; Sequeira, M. C.; Zhang, Z.; Venkatesh, S.; Alves, E.; Lorenz, K.; Roqan, Iman S.

    2016-01-01

    Gd-doped ZnO thin films were prepared using pulsed laser deposition at different oxygen pressures and varied Gd concentrations. The effects of oxygen deficiency-related defects on the Gd incorporation, optical and structural properties, were explored by studying the impact of oxygen pressure during deposition and post-growth thermal annealing in vacuum. Rutherford Backscattering Spectrometry revealed that the Gd concentration increases with increasing oxygen pressure for samples grown with the same Gd-doped ZnO target. Unexpectedly, the c-lattice parameter of the samples tends to decrease with increasing Gd concentration, suggesting that Gd-defect complexes play an important role in the structural properties. Using low-temperature photoluminescence(PL), Raman measurements and density functional theory calculations, we identified oxygen vacancies as the dominant intrinsic point defects. PL spectra show a defect band related to oxygen vacancies for samples grown at oxygen deficiency.

  15. Influence of silver and copper doping on luminescent properties of zinc-phosphate glasses after x-ray irradiation

    Science.gov (United States)

    Murashov, Alexander A.; Sidorov, Alexander I.; Shakhverdov, Teimur A.; Stolyarchuk, Maxim V.

    2017-11-01

    It is shown, experimentally, that in silver- and copper-containing zinc-phosphate glasses, metal molecular clusters are formed during the glass synthesis. X-ray irradiation of these glasses led to the considerable increase of its luminescence in visible spectral range. This effect is caused by the transformation of the charged metal molecular clusters into the neutral state. Luminescence and excitation spectra of the glass, doped with silver and copper simultaneously, change significantly in comparison with the spectra of glasses doped with one metal. The reason for this can be the formation of hybrid AgnCum molecular clusters. The computer simulation of the structure and optical properties of such clusters by the time-dependent density functional theory method is presented. It is shown that the optimal luminescent material for photonics application, in comparison with other studied materials, is glass, containing hybrid molecular clusters.

  16. Influence of hydrogen impurities on p-type resistivity in Mg-doped GaN films

    International Nuclear Information System (INIS)

    Yang, Jing; Zhao, Degang; Jiang, Desheng; Chen, Ping; Zhu, Jianjun; Liu, Zongshun; Le, Lingcong; He, Xiaoguang; Li, Xiaojing; Zhang, Y. T.; Du, G. T.

    2015-01-01

    The effects of hydrogen impurities on p-type resistivity in Mg-doped GaN films were investigated. It was found that hydrogen impurities may have the dual role of passivating Mg Ga acceptors and passivating donor defects. A decrease in p-type resistivity when O 2 is introduced during the postannealing process is attributed to the fact that annealing in an O 2 -containing environment can enhance the dissociation of Mg Ga -H complexes as well as the outdiffusion of H atoms from p-GaN films. However, low H concentrations are not necessarily beneficial in Mg-doped GaN films, as H atoms may also be bound at donor species and passivate them, leading to the positive effect of reduced compensation

  17. Identifying the influence of the intrinsic defects in Gd-doped ZnO thin-films

    KAUST Repository

    Flemban, Tahani H.

    2016-02-08

    Gd-doped ZnO thin films were prepared using pulsed laser deposition at different oxygen pressures and varied Gd concentrations. The effects of oxygen deficiency-related defects on the Gd incorporation, optical and structural properties, were explored by studying the impact of oxygen pressure during deposition and post-growth thermal annealing in vacuum. Rutherford Backscattering Spectrometry revealed that the Gd concentration increases with increasing oxygen pressure for samples grown with the same Gd-doped ZnO target. Unexpectedly, the c-lattice parameter of the samples tends to decrease with increasing Gd concentration, suggesting that Gd-defect complexes play an important role in the structural properties. Using low-temperature photoluminescence(PL), Raman measurements and density functional theory calculations, we identified oxygen vacancies as the dominant intrinsic point defects. PL spectra show a defect band related to oxygen vacancies for samples grown at oxygen deficiency.

  18. Investigation of the Influence of Ni Doping on the Structure and Hardness of Ti-Ni-C Coatings

    Directory of Open Access Journals (Sweden)

    J. Daniel

    2017-01-01

    Full Text Available Nanocomposite nc-TiC/a-C:H thin films exhibit unique combination of mechanical properties, high hardness, low friction, and wear. Selective doping by weak-carbide forming element can be used in order to specifically design the physical and chemical properties of nc-TiC/a-C:H coatings. In this paper we report on an effect of nickel addition on structure and hardness of the nc-TiC/a-C:H coatings. The effect of Ni alloying on the coating structure under conditions of DCMS and HiPIMS depositions was studied. The coating structure was correlated with the coating hardness. The grain size, the grain carbon vacancy concentration, and the mean grain separation were found to be the key parameters determining the coating hardness. Ni doping proved to have a significant effect on the coating microstructure which resulted in changes of the hardness of the deposited coatings.

  19. Influence of Zr doping on structure and morphology of TiO2 nanorods prepared using hydrothermal method

    Science.gov (United States)

    Muslimin, Masliana; Jumali, Mohammad Hafizuddin; Tee, Tan Sin; Beng, Lee Hock; Hui, Tan Chun; Chin, Yap Chi

    2018-04-01

    The aim of this work is to investigate the effect of Zr doping on TiO2 nanostructure. TiO2 nanorods thin films with different Zr-doping concentrations (6 × 10-3 M, 13 × 10-3 M and 25 × 10-3 M) were successfully prepared using a simple hydrothermal method. The structural and morphological properties of the samples were evaluated using XRD and FESEM respectively. The XRD results revealed that the TiO2 in all samples stabilized as rutile phase. The FESEM micrographs confirmed that TiO2 exist as square like nanorods with blunt tips. Although the crystallographic nature remains unchanged, the introduction of Zr has altered the surface density, structure and morphology of TiO2 which subsequently will have significant effect on its properties.

  20. Influence of Ag doping on structural, optical, and photoluminescence properties of nanostructured AZO films by sol–gel technique

    International Nuclear Information System (INIS)

    Khan, Firoz; Baek, Seong-Ho; Kim, Jae Hyun

    2014-01-01

    Graphical abstract: The optical band gap of the Ag–AZO film first decreased to a value of ∼3.31 eV for a 1% Ag/Zn atomic ratio from a value of ∼3.69 for undoped AZO film. For higher values (beyond a 1% Ag/Zn atomic ratio) of Ag doping, the values of Eg started to increase and finally attained a value of ∼3.66 eV for an Ag/Zn 3% atomic ratio. The photoluminescence (PL) studies showed that the relative PL intensity of the Ag–AZO films in blue (IB) and green (IG) regions increased with Ag doping. The PL positions of these peaks were blue shifted with increased Ag content up to an Ag/Zn atomic ratio of 3%. The increase in IB and IG is due to the charge difference between Ag + and Zn 2+ , whereas shifting of the PL positions is due to the size of Ag + and Zn 2+ ions. -- Highlights: • The optical band gap of the Ag–AZO film is tuned with Ag doping. • The PL intensity of the Ag–AZO film in visible region is increased with Ag doping. • The PL positions of these peaks were blue shifted with increased Ag content. • The increase in I B and I G is due to the charge difference between Ag + and Zn 2+ . • The shifting of the PL positions is due to the size of Ag + and Zn 2+ ions. -- Abstract: The effects of Ag doping on the structural, electrical, optical, and photoluminescence properties of sol-gel derived Al rich zinc oxide (Ag–AZO) films are studied. The Al/Zn atomic ratio was constant (∼20%) in all the films, whereas the Ag/Zn atomic ratio varied from 0% to 3%. All the films were highly transparent in the 400–1200 nm wavelength range. The XRD results and surface morphologies of the films confirmed that the grain size increased with Ag doping. The optical band gap (E g ) of the Ag–AZO film first decreased to a value of ∼3.31 eV for a 1% Ag/Zn atomic ratio from a value of ∼3.69 for undoped AZO film. For higher values (beyond a 1% Ag/Zn atomic ratio) of Ag doping, the values of E g started to increase and finally attained a value of ∼3.66 e

  1. Influence of boron content on the morphological, spectral, and electroanalytical characteristics of anodically oxidized boron-doped diamond electrodes

    Czech Academy of Sciences Publication Activity Database

    Schwarzová-Pecková, K.; Vosáhlová, J.; Barek, J.; Šloufová, I.; Pavlova, Ewa; Petrák, Václav; Zavázalová, J.

    2017-01-01

    Roč. 243, 20 July (2017), s. 170-182 ISSN 0013-4686 R&D Projects: GA TA ČR(CZ) TE01020118 Institutional support: RVO:61389013 ; RVO:68378271 Keywords : 2-aminobiphenyl * boron content * boron-doped diamond Subject RIV: CD - Macromolecular Chemistry; CG - Electrochemistry (FZU-D) OBOR OECD: Polymer science; Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis) (FZU-D) Impact factor: 4.798, year: 2016

  2. Influence of photoinduced Bi-related self-doping on the photocatalytic activity of BiOBr nanosheets

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Dan [School of Life Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR (China); Yue, Songtao; Wang, Wei [College of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); An, Tiacheng, E-mail: antc99@gig.ac.cn [Institute of Environmental Health and Pollution Control, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006 (China); Li, Guiying [Institute of Environmental Health and Pollution Control, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006 (China); Ye, Liqun [School of Life Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR (China); College of Chemistry and Pharmaceutical Engineering, Nanyang Normal University, Nanyang 473061 (China); Yip, Ho Yin [School of Life Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR (China); Wong, Po Keung, E-mail: pkwong@cuhk.edu.hk [School of Life Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR (China)

    2017-01-01

    Highlights: • Bi{sup 5+} self-doped BiOBr nanosheets are achieved under UV irradiation. • Bi{sup 5+} is formed due to the oxidation of surface Bi{sup 3+} by photoexcited h{sup +} of BiOBr. • Two photoinduced h{sup +} mediated oxidation processes happen simultaneously. • Self-doped BiOBr is superior in phenol degradation and bacterial inactivation. • Bi{sup 5+} electron trapping induced photocatalytic enhancement mechanism is proposed. - Abstract: Under UV irradiation, self-doped Bi{sup 5+} is evidenced to be generated on the surface of BiOBr nanosheets, but with well-preserved crystal structure and morphology compared with pure counterpart. Bi{sup 5+} self-doping BiOBr (BiOBr-4) exhibits distinct photocatalytic mode for dyes degradation, as compared with pure BiOBr nanosheets. These photodegradation distinctions are mainly due to the simultaneous occurrence of two photoinduced hole (h{sup +}) mediated oxidation processes on the BiOBr surfaces: (1) a portion of photoexcited h{sup +} participates in the photocatalytic oxidation of dyes, and (2) partial h{sup +} involves the oxidation of Bi{sup 3+} to Bi{sup 5+}. Notably, BiOBr-4 nanosheets comparatively show superior photocatalytic activity for the phenol decomposition as well as the bacterial inactivation. Besides Bi{sup 5+} induced narrowed bandgap and enhanced light adsorption capacity, significantly, the oxidative Bi{sup 5+} acts as electron traps to promote the photoexcited electron-hole separation and accelerate h{sup +} migration, resulting in the considerable photocatalytic enhancement of BiOBr-4 nanosheets. These novel findings will not only give new insights into the photocatalytic mechanism but also explore new route to enhance photocatalytic performance of Bi-based materials.

  3. In line wood plastic composite pyrolyses and HZSM-5 conversion of the pyrolysis vapors

    International Nuclear Information System (INIS)

    Lin, Xiaona; Zhang, Zhijun; Tan, Shun; Wang, Fengqiang; Song, Yongming; Wang, Qingwen; Pittman, Charles U.

    2017-01-01

    Graphical abstract: HZSM-5 can be used to catalytic convert Wood Fiber-Polypropylene or Wood Fiber-Polypropylene pyrolysis vapors into aromatic compounds in reasonable selectivities. This provides a recycling utilization WPCs wastes method. - Highlights: • Converting wood/plastic composites (WPC) wastes into aromatics. • Recycling WPC by fast pyrolysis coupled with vapor catalytic cracking. • Selective production of aromatics from WPCs and their components over HZSM-5. • Acid site concentration inside zeolite was critical for maximizing aromatic yield. • Synergistic effects between wood and plastics enhanced aromatics production. - Abstract: Wood powder-high density polyethylene (WPE) and wood powder-polypropylene (WPP) composites were pyrolyzed at 550 °C in the presence of HZSM-5 catalysts using analytical pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Immediately passing the pyrolysis vapors through the HZSM-5 changed the product distribution by producing aromatic hydrocarbons and eliminating tar formation. Zeolite HZSM-5 was employed with three different silica-to-alumina ratios (25, 50, 260). The influence of catalysts on the yields of aliphatic and aromatic hydrocarbons, furan derivatives, lignin-derived compounds and acetic acid was studied. High yields of aliphatic hydrocarbons formed in WPE or WPP pyrolysis alone. The highest yields of aromatic hydrocarbons from WPE or WPP pyrolysis vapors over HZSM-5 occurred with a zeolite framework Si/Al ratio of 25 (more acid sites), suggesting that the concentration of acid sites inside the zeolite was critical for maximizing aromatic yield. Exposing vapors to HZSM-5 increased the hydrocarbon yields and reduced the amount of acetic acid produced, resulting in increased calorific value. The yields of typical aromatics from catalytic pyrolysis of WPP mixture and composites were higher than those of the calculated values of poplar wood and PP catalytic pyrolysis individually, indicating that a

  4. Influence of Sn ion doping on the photocatalytic performance of V2O5 nanorods prepared by hydrothermal method

    Science.gov (United States)

    Rajeshwari, S.; Santhosh Kumar, J.; Rajendrakumar, R. T.; Ponpandian, N.; Thangadurai, P.

    2018-02-01

    Pure and different concentrations of Sn4+ doped V2O5 (Sn:V2O5) nanorods were synthesized by hydrothermal method. The Sn:V2O5 nanorods obtained were orthorhombic in structure. No secondary phase was observed up to 10% of Sn doping, but beyond that, there evolved a secondary phase of SnO2. Microstructural analysis revealed the morphology of V2O5 as nanorods and platelets like structure. Presence of V, O and Sn elements in the samples was confirmed by energy dispersive spectroscopy. The V2O5 nanorods have shown a strong absorption in the visible region and the band gap energy was obtained to be varying from 2.21 to 2.26 eV as a function of Sn ion doping. Photocatalytic studies on methylene blue (MB) under visible light irradiation showed that the 3% Sn:V2O5 had effectively degraded MB up to a maximum degradation of 96% and further increase in Sn content had decreased the photodegradation due to higher recombination rate of photogenerated electrons. The mechanism of photodegradation was completely understood and the OH· radicals have played a dominant role in the photodegradation of the organic dyes.

  5. Influence of B doping on the carrier transport mechanism and barrier height of graphene/ZnO Schottky contact

    Science.gov (United States)

    Li, Yapeng; Li, Yingfeng; Zhang, Jianhua; Tong, Ting; Ye, Wei

    2018-03-01

    The ZnO films were fabricated on the surface of n-Si(1 1 1) substrate using the sol-gel method, and the graphene was then transferred to its surface for the fabrication of the graphene/ZnO Schottky contact. The results showed that ZnO films presented a strong (0 0 2) preferred direction, and that the particle sizes on the surface decreased as the doping concentration of B ions increased. The electrical properties of the graphene/ZnO Schottky contact were measured by using current-voltage measurements. It was found that the graphene/ZnO Schottky contact showed a fine rectification behavior when the doping concentration of B ions was increased. However, when the doping concentration of the B ions increased to 0.15 mol l-1, the leakage current increased and rectification behavior weakened. This was due to the Fermi level pinning caused by the presence of the O vacancy at the interface of the graphene/ZnO Schottky contact.

  6. Influence of annealing temperature on optical properties of Al doped ZnO nanoparticles via sol-gel methods

    Science.gov (United States)

    Rashid, Affa Rozana Abd; Hazwani, Tuan Nur; Mukhtar, Wan Maisarah; Taib, Nur Athirah Mohd

    2018-06-01

    Zinc oxide (ZnO) thin films have become technologically important materials due to their wide range of electrical and optical properties. The characteristics can be further adjusted by adequate doping processes. The effect of dopant concentration of Al, heating treatment and annealing in reducing atmosphere on the optical properties of the thin films is discussed. Undoped and aluminum-doped zinc oxide (AZO) thin films are prepared by the sol-gel method. Zinc acetate dihydrate, 2-methoxyethanol and monoethanolamine are used as precursor, solvent and stabilizer. In the case of AZO, aluminum nitrate nanohydrate is added to the precursor solution with an atomic percentage equal to 0 %, 1 %, 2 % and 3 % of Al. The multi thin layers are transformed into ZnO upon annealing at 450 °C and 500 °C. The optical properties such as transmittance, absorbance, band gap and refractive index of the thin films have been investigated by using UV-Visible Spectroscopy (UV-Vis). The results show that the effect of aluminium dopant concentration on the optical properties is depend on the post-heat treatment of the films. By doping with Al, the transmittance spectra in visible range increased and widen the band gap of ZnO which might due to Burstein-moss effects.

  7. Influence of La doping on structural and dielectric properties of SrBi2Nb2O9 ceramics

    International Nuclear Information System (INIS)

    Verma, Maya; Sreenivas, K.; Gupta, Vinay

    2009-01-01

    Lanthanum doped SrBi 2 Nb 2 O 9 ceramics with the chemical formula SrBi 2-x La x Nb 2 O 9 (SBLN) (x=0-0.5) have been prepared through conventional solid state route. X-ray diffraction reveals the shrinkage of unit cell of strontium bismuth niobate with incorporation of La 3+ dopant, having no lone pair electrons. Shifting of Raman phonon modes indicates the reduced rattling space of NbO 6 octahedra with increase in La doping concentration. Further, the softening of lowest frequency phonon mode with increasing x in SBLN shows the transition from ferroelectric to paraelectric at room temperature. The dielectric properties for all the compositions are studied as a function of temperature (25 to 500 deg. C) over the frequency range of 10 kHz-1 MHz. With increase in lanthanum doping concentration the phase transition becomes diffused and transition temperature gets shifted toward lower temperature. A phase transition from normal ferroelectric to paraelectric has been observed via relaxor-type ferroelectrics with increase in x. The frequency dependence of transition temperature was studied in terms of Vogel-Fulcher relation for SBLN (x=0.4)

  8. Influence of La doping on structural and dielectric properties of SrBi2Nb2O9 ceramics

    Science.gov (United States)

    Verma, Maya; Sreenivas, K.; Gupta, Vinay

    2009-01-01

    Lanthanum doped SrBi2Nb2O9 ceramics with the chemical formula SrBi2-xLaxNb2O9 (SBLN) (x =0-0.5) have been prepared through conventional solid state route. X-ray diffraction reveals the shrinkage of unit cell of strontium bismuth niobate with incorporation of La3+ dopant, having no lone pair electrons. Shifting of Raman phonon modes indicates the reduced rattling space of NbO6 octahedra with increase in La doping concentration. Further, the softening of lowest frequency phonon mode with increasing x in SBLN shows the transition from ferroelectric to paraelectric at room temperature. The dielectric properties for all the compositions are studied as a function of temperature (25 to 500 °C) over the frequency range of 10 kHz-1 MHz. With increase in lanthanum doping concentration the phase transition becomes diffused and transition temperature gets shifted toward lower temperature. A phase transition from normal ferroelectric to paraelectric has been observed via relaxor-type ferroelectrics with increase in x. The frequency dependence of transition temperature was studied in terms of Vogel-Fulcher relation for SBLN (x =0.4).

  9. Influence of indium doping on the properties of zinc tin oxide films and its application to transparent thin film transistors

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Mu Hee; Ma, Tae Young, E-mail: tyma@gnu.ac.kr

    2014-01-01

    In this study, the effects of indium (In) doping on the properties of zinc tin oxide (ZTO) films are reported. ZTO films were prepared by RF magnetron sputtering followed by In layer deposition, for use as the diffusion source. In order to protect the In layer from peeling, a second ZTO film was deposited on the In film. The annealing at 400 °C for 30 min was carried out to diffuse In atoms into the ZTO films. The structural, optical, and elemental properties of the annealed ZTO/In/ZTO films were investigated by X-ray diffraction, UV/vis spectrophotometry, and X-ray photoluminescence spectroscopy, respectively. The ZTO transparent thin film transistors employing the ZTO/In/ZTO films as the source/drain were prepared, and the effects of the In doped source/drain on the threshold voltage and mobility were characterized and analyzed. - Highlights: • We successfully doped zinc tin oxide (ZTO) films using In as a diffusion source. • Indium (In) was diffused in both directions with the diffusion coefficient of ∼ 4.3 × 10{sup −16} cm{sup 2}/s. • The mobility of ZTO thin film transistor was increased 1.6-times by adopting the In-diffused source/drain.

  10. Doping influence by some transition elements on the irradiation effects in nuclear waste glasses; Influence du dopage par certains elements de transition sur les effets d'irradiation dans des verres d'interet nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Florent, Olivier

    2006-06-15

    High-level waste glasses are submitted to auto-irradiation. Modelling it using external irradiations on simple glasses revealed defects production and non negligible structural changes. This thesis aims at determining the impact of a more complex composition on these effects, especially the influence of adding polyvalent transition metals. Silicate, soda-lime and alumino-borosilicate glasses are doped with different iron, chromium and manganese concentrations then {beta} irradiated at different doses up to 10{sup 9} Gy. Non doped glasses show an increase of their density and polymerisation coupled with a molecular oxygen and point defects production. Adding 0.16 mol% Fe decreases the amount of defects by 85 % and all irradiation effects. A Fe{sup 3+} reduction is also observed by EPR, optical absorption and indirectly by Raman spectroscopy. A higher than 0.32 mol% Fe concentration causes complete blockage of the evolution of polymerisation, density and defect production. The same results are obtained on chromium or manganese doped glasses. An original in situ optical absorption device shows the quick decrease of Fe{sup 3+} amount to a 25 % lower level during irradiation. Stopping irradiation causes a lower decrease of 65 %, suggesting a dynamic (h{sup 0}/e-) consuming equilibrium. He{sup +} and Kr{sup 3+} ions and {gamma} irradiated glasses tend to confirm these phenomena for all kind of irradiation with electronic excitations. (author)

  11. Pyrolysis - gas chromatography - mass spectrometry of lignins

    Energy Technology Data Exchange (ETDEWEB)

    Martin, F; Saiz-Jimenez, C; Gonzalez-Vila, F J

    1979-01-01

    Milled wood lignins from spruce, beech and bamboo were pyrolysed. The high-boiling products of pyrolysis were studied by GLC and mass spectrometry. The forty-three products identified provide information on the structural units of lignin.

  12. Production of Lunar Oxygen Through Vacuum Pyrolysis

    National Research Council Canada - National Science Library

    Matchett, John

    2006-01-01

    .... The vacuum pyrolysis method of oxygen production from lunar regolith presents a viable option for in situ propellant production because of its simple operation involving limited resources from earth...

  13. Influence of substrate temperature and silver-doping on the structural and optical properties of TiO_2 films

    International Nuclear Information System (INIS)

    Fischer, Dieter

    2016-01-01

    Evaporation of titanium together with activated oxygen is used to grow TiO_2 films and simultaneously with silver to grow Ag–TiO_2 films (5 at.% Ag) onto sapphire substrates at three different substrate temperatures: − 190, 30, and 200 °C. The obtained films were characterized by X-ray powder diffraction, Raman, X-ray photoelectron, ultraviolet–visible spectroscopy, and transmission electron microscope investigations. The properties of TiO_2 films varied with the substrate temperature. Amorphous, transparent TiO_2 films were grown at − 190 °C and opaque, polycrystalline films at 200 °C, respectively. Surprisingly, at room temperature black, amorphous TiO_2 films are obtained which transform at 350 °C into a mixture of the anatase and brookite polymorph. In the amorphous state of the TiO_2 films a predefined rutile arrangement is suggested by Raman investigations, and the contraction of the lattice constant c of anatase phases (tetragonal, space group I 4_1/amd) depending on the substrate temperature is experimentally observed. The silver-doped TiO_2 films deposited at − 190 and 30 °C contain Ag-particles with 2 nm in size inside the TiO_2 matrix, which after annealing segregate under increasing particle sizes. The silver-doping stabilizes the anatase polymorph and yields to reduced titanium species in the films especially during deposition at 30 °C. The Ag–TiO_2 films deposited at − 190 °C are transparent up to 350 °C. In the undoped as well as silver-doped TiO_2 films the rutile polymorph is directly formed at 200 °C as main phase. - Highlights: • At room temperature black, amorphous TiO_2 films are obtained. • A predefined rutile arrangement is suggested in amorphous TiO_2 films. • Annealed TiO_2 films crystallize to a mixture of the anatase and brookite polymorph. • In TiO_2 and Ag-doped TiO_2 films the rutile polymorph is directly formed at 200 °C. • Ag-doped TiO_2 films stabilize the anatase polymorph and reduced titanium

  14. Experimental and modeling study on pyrolysis of n-decane initiated by nitromethane

    KAUST Repository

    Jia, Zhenjian

    2016-01-15

    Initiator could accelerate the rate of hydrocarbon pyrolysis and reduce the required material temperatures for a hypersonic aircraft heat exchanger/reactor. Nitroalkanes were proposed as the effective initiator because of the lower CN bond dissociation energy. In order to investigate the initiation mechanism of nitroalkanes on hydrocarbon pyrolysis, the pyrolysis of n-decane, nitromethane and their binary mixture were carried out at 30, 150 and 760 Torr in a flow reactor with synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS). The identified and quantified pyrolysis species include C1C2 alkanes, C2C10 alkenes, C3C6 dialkenes, C2C3 alkynes, nitrogen oxides such as NO and NO2, benzene, and radicals including CH3, C3H3, and C3H5, which shed light on the mechanism of n-decane and nitromethane pyrolysis, as well as the interactions of these two fuels. The experimental results indicate that the addition of nitromethane decreases the initial decomposition temperature of n-decane, and a stronger promotion effect could be obtained as the experimental pressure increases. The distributions of alkanes, alkenes, dialkenes, alkynes and benzene are also influenced by the addition of nitromethane. A detailed kinetic model with 266 species and 1648 reactions was developed and validated against the mole fraction profiles of reactants, major products and important intermediates during the pyrolysis of each fuel and their binary mixture. The satisfactory model prediction to the experimental measurements permits the analysis of the kinetic effect of nitromethane initiation on the pyrolysis of n-decane. So that, the increase of the conversion rate at a lower temperature, the selectivity of decomposition products, and reduction of benzene formation are better understood.

  15. Influence of duty ratio of pulsed bias on structure and properties of silicon-doped diamond-like carbon films by plasma deposition

    International Nuclear Information System (INIS)

    Nakazawa, Hideki; Kamata, Ryosuke; Miura, Soushi; Okuno, Saori

    2013-01-01

    We have investigated the influence of the duty ratio of pulsed substrate bias on the structure and properties of Si-doped diamond-like carbon (Si-DLC) films deposited by radio frequency plasma-enhanced chemical vapor deposition using CH 4 , Ar, and monomethylsilane (CH 3 SiH 3 ) as the Si source. The Si/(Si + C) ratios in the Si-DLC films deposited using pulsed bias were higher than that of the dc-biased Si-DLC film, and the Si fraction increased with decreasing pulse duty ratio. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses revealed that Si-C, Si-H n , and C-H n bonds in the Si-DLC films increased with decreasing duty ratio. The internal stress decreased as the duty ratio decreased, which is probably due to the increase in Si-C, Si-H n , and C-H n bonds in the films. The Si-DLC films deposited using pulsed bias had higher adhesion strength than the dc-biased Si-DLC film because of the further reduction of internal stress. At higher duty ratios, although the Si fractions of the pulse-biased Si-DLC films were higher than that of the dc-biased Si-DLC film, the wear rates of the former were less than that of the latter. - Highlights: • The internal stress of Si-doped films was lowered at lower duty ratios. • The adhesion of pulse-biased films was improved compared with that of dc films. • The tribological properties of Si-doped films were improved by the use of pulse bias

  16. Oxidative desulfurization of tire pyrolysis oil

    OpenAIRE

    Ahmad Shahzad; Ahmad Muhammad Imran; Naeem Khawar; Humayun Muhammad; Sebt-E-Zaeem; Faheem Farrukh

    2016-01-01

    This paper presents a low cost method for the purification of oils obtained from the pyrolysis of used tires. Oxidative desulfurization is a promising route for purification of tire pyrolysis oils as hydro-desulfurization may not be affordable for small scale industries. Different additives and acids have been employed for the enhancement of properties of pyrolytic oils. The experimental conditions were kept identical throughout, i.e. atmospheric pressure a...

  17. Pyrolysis of D-Glucose to Acrolein

    Science.gov (United States)

    Shen, Chong; Zhang, Igor Ying; Fu, Gang; Xu, Xin

    2011-06-01

    Despite of its great importance, the detailed molecular mechanism for carbohydrate pyrolysis remains poorly understood. We perform a density functional study with a newly developed XYG3 functional on the processes for D-glucose pyrolysis to acrolein. The most feasible reaction pathway starts from an isomerization from D-glucose to D-fructose, which then undergoes a cyclic Grob fragmentation, followed by a concerted electrocyclic dehydration to yield acrolein. This mechanism can account for the known experimental results.

  18. Airplane dopes and doping

    Science.gov (United States)

    Smith, W H

    1919-01-01

    Cellulose acetate and cellulose nitrate are the important constituents of airplane dopes in use at the present time, but planes were treated with other materials in the experimental stages of flying. The above compounds belong to the class of colloids and are of value because they produce a shrinking action on the fabric when drying out of solution, rendering it drum tight. Other colloids possessing the same property have been proposed and tried. In the first stages of the development of dope, however, shrinkage was not considered. The fabric was treated merely to render it waterproof. The first airplanes constructed were covered with cotton fabric stretched as tightly as possible over the winds, fuselage, etc., and flying was possible only in fine weather. The necessity of an airplane which would fly under all weather conditions at once became apparent. Then followed experiments with rubberized fabrics, fabrics treated with glue rendered insoluble by formaldehyde or bichromate, fabrics treated with drying and nondrying oils, shellac, casein, etc. It was found that fabrics treated as above lost their tension in damp weather, and the oil from the motor penetrated the proofing material and weakened the fabric. For the most part the film of material lacked durability. Cellulose nitrate lacquers, however were found to be more satisfactory under varying weather conditions, added less weight to the planes, and were easily applied. On the other hand, they were highly inflammable, and oil from the motor penetrated the film of cellulose nitrate, causing the tension of the fabric to be relaxed.

  19. Chemical disorder influence on magnetic state of optimally-doped La0.7Ca0.3MnO3

    Science.gov (United States)

    Rozenberg, E.; Auslender, M.; Shames, A. I.; Jung, G.; Felner, I.; Tsindlekht, M. I.; Mogilyansky, D.; Sominski, E.; Gedanken, A.; Mukovskii, Ya. M.; Gorodetsky, G.

    2011-10-01

    X-band electron magnetic resonance and dc/ac magnetic measurements have been employed to study the effects of chemical disorder on magnetic ordering in bulk and nanometer-sized single crystals and bulk ceramics of optimally-doped La0.7Ca0.3MnO3 manganite. The magnetic ground state of bulk samples appeared to be ferromagnetic with the lower Curie temperature and higher magnetic homogeneity in the vicinity of the ferromagnetic-paramagnetic phase transition in the crystal, as compared with those characteristics in the ceramics. The influence of technological driven "macroscopic" fluctuations of Ca-dopant level in crystal and "mesoscopic" disorder within grain boundary regions in ceramics was proposed to be responsible for these effects. Surface spin disorder together with pronounced inter-particle interactions within agglomerated nano-sample results in well defined core/shell spin configuration in La0.7Ca0.3MnO3 nano-crystals. The analysis of the electron paramagnetic resonance data enlightened the reasons for the observed difference in the magnetic order. Lattice effects dominate the first-order nature of magnetic phase transition in bulk samples. However, mesoscale chemical disorder seems to be responsible for the appearance of small ferromagnetic polarons in the paramagnetic state of bulk ceramics. The experimental results and their analysis indicate that a chemical/magnetic disorder has a strong impact on the magnetic state even in the case of mostly stable optimally hole-doped manganites.

  20. Passivation of phosphorus diffused silicon surfaces with Al2O3: Influence of surface doping concentration and thermal activation treatments

    International Nuclear Information System (INIS)

    Richter, Armin; Benick, Jan; Kimmerle, Achim; Hermle, Martin; Glunz, Stefan W.

    2014-01-01

    Thin layers of Al 2 O 3 are well known for the excellent passivation of p-type c-Si surfaces including highly doped p + emitters, due to a high density of fixed negative charges. Recent results indicate that Al 2 O 3 can also provide a good passivation of certain phosphorus-diffused n + c-Si surfaces. In this work, we studied the recombination at Al 2 O 3 passivated n + surfaces theoretically with device simulations and experimentally for Al 2 O 3 deposited with atomic layer deposition. The simulation results indicate that there is a certain surface doping concentration, where the recombination is maximal due to depletion or weak inversion of the charge carriers at the c-Si/Al 2 O 3 interface. This pronounced maximum was also observed experimentally for n + surfaces passivated either with Al 2 O 3 single layers or stacks of Al 2 O 3 capped by SiN x , when activated with a low temperature anneal (425 °C). In contrast, for Al 2 O 3 /SiN x stacks activated with a short high-temperature firing process (800 °C) a significant lower surface recombination was observed for most n + diffusion profiles without such a pronounced maximum. Based on experimentally determined interface properties and simulation results, we attribute this superior passivation quality after firing to a better chemical surface passivation, quantified by a lower interface defect density, in combination with a lower density of negative fixed charges. These experimental results reveal that Al 2 O 3 /SiN x stacks can provide not only excellent passivation on p + surfaces but also on n + surfaces for a wide range of surface doping concentrations when activated with short high-temperature treatments

  1. Effect of fast pyrolysis conditions on biomass solid residues at high temperatures

    DEFF Research Database (Denmark)

    Trubetskaya, Anna; Jensen, Peter Arendt; Jensen, Anker Degn

    2016-01-01

    Fast pyrolysis of wood and straw was conducted in a drop tube furnace (DTF) and compared with corresponding data from a wire mesh reactor (WMR) to study the influence of temperature (1000-1400)°C, biomass origin (pinewood, beechwood, wheat straw, alfalfa straw), and heating rate (103 °C/s, 104 °C...... in its half-width with respect to the parental fuel, whereas the alfalfa straw char particle size remained unaltered at higher temperatures. Soot particles in a range from 60 to 300 nm were obtained during fast pyrolysis. The soot yield from herbaceous fuels was lower than from wood samples, possibly due...

  2. Effects of mineral matters on evolution of sulfur-containing gases in pyrolysis and hydropyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Chen, H.; Li, B.; Zhang, B. [Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan (China). State Key Lab. of Coal Conversion

    1998-07-01

    The evolution of sulfur-containing gases were investigated using two Chinese coals with their de-ash and de-pyrite forms in pyrolysis and hydropyrolysis. Mineral matter can not only return H{sub 2}S produced in pyrolysis and hydropyrolysis, but also catalyse hydrodesulfurization and reduce COS formation. Secondary reactions markedly influence COS formation. Mineral matter can reduce CH{sub 3}SH formation, and pyrite shows positive effects on CH{sub 3}SH formation. 7 refs., 6 figs., 1 tab.

  3. Effects of pressure on morphology and structure of bio-char from pressurized entrained-flow pyrolysis of microalgae

    Directory of Open Access Journals (Sweden)

    Kristina Maliutina

    2018-06-01

    Full Text Available The present dataset describes the entrained-flow pyrolysis of Microalgae Chlorella vulgaris and the results obtained during bio-char characterization. The dataset includes a brief explanation of the experimental procedure, experimental conditions and the influence of pyrolysis conditions on bio-chars morphology and carbon structure. The data show an increase in sphericity and surface smoothness of bio-chars at higher pressures and temperatures. Data confirmed that the swelling ratio of bio-chars increased with pressure up to 2.0 MPa. Consequently, changes in carbon structure of bio-chars were investigated using Raman spectroscopy. The data showed the increase in carbon order of chars at elevated pressures. Changes in the chemical structure of bio-char as a function of pyrolysis conditions were investigated using FTIR analysis. Keywords: Microalgae, Bio-char, Particle swelling, Pressurized pyrolysis

  4. Effects of reaction conditions on the emission behaviors of arsenic, cadmium and lead during sewage sludge pyrolysis.

    Science.gov (United States)

    Han, Hengda; Hu, Song; Syed-Hassan, Syed Shatir A; Xiao, Yiming; Wang, Yi; Xu, Jun; Jiang, Long; Su, Sheng; Xiang, Jun

    2017-07-01

    Sewage sludge is an important class of bioresources whose energy content could be exploited using pyrolysis technology. However, some harmful trace elements in sewage sludge can escape easily to the gas phase during pyrolysis, increasing the potential of carcinogenic material emissions to the atmosphere. This study investigates emission characteristics of arsenic, cadmium and lead under different pyrolysis conditions for three different sewage sludge samples. The increased temperature (within 723-1123K) significantly promoted the cadmium and lead emissions, but its influence on arsenic emission was not pronounced. The releasing rate order of the three trace elements is volatile arsenic compounds>cadmium>lead in the beginning of pyrolysis. Fast heating rates promoted the emission of trace elements for the sludge containing the highest amount of ash, but exhibited an opposite effect for other studied samples. Overall, the high ash sludge released the least trace elements almost under all reaction conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Effect of Fast Pyrolysis Conditions on Structural Transformation and Reactivity of Herbaceous Biomasses at High Temperatures

    DEFF Research Database (Denmark)

    Trubetskaya, Anna; Jensen, Anker D.; Jensen, Peter Arendt

    of organic and inorganic matter on the char structural transformations. The results indicate no influence of the free radicals on char reactivity and burnout. The formation of free radicals in fast pyrolysis is related to the differences in the ash composition, namely presence of K+ ions in the wheat straw...

  6. Influence of a doping by Al stainless steel on kinetics and character of interaction with the metallic nuclear fuel

    Science.gov (United States)

    Nikitin, S. N.; Shornikov, D. P.; Tarasov, B. A.; Baranov, V. G.

    2016-04-01

    Metallic nuclear fuel is a perspective kind of fuel for fast reactors. In this paper we conducted a study of the interaction between uranium-molybdenum alloy and ferritic- martensitic steels with additions of aluminum at a temperature of 700 ° C for 25 hours. The rate constants of the interaction layer growth at 700 °C is about 2.8.10-14 m2/s. It is established that doping Al stainless steel leads to decrease in interaction with uranium-molybdenum alloys. The phase composition of the interaction layer is determined.

  7. The influence of carbon doping on the performance of Gd2O3 as high-k gate dielectric

    International Nuclear Information System (INIS)

    Shekhter, P.; Yehezkel, S.; Shriki, A.; Eizenberg, M.; Chaudhuri, A. R.; Osten, H. J.; Laha, A.

    2014-01-01

    One of the approaches for overcoming the issue of leakage current in modern metal-oxide-semiconductor devices is utilizing the high dielectric constants of lanthanide based oxides. We investigated the effect of carbon doping directly into Gd 2 O 3 layers on the performance of such devices. It was found that the amount of carbon introduced into the dielectric is above the solubility limit; carbon atoms enrich the oxide-semiconductor interface and cause a significant shift in the flat band voltage of the stack. Although the carbon atoms slightly degrade this interface, this method has a potential for tuning the flat band voltage of such structures

  8. Influence of the doping type and level on the morphology of porous Si formed by galvanic etching

    Energy Technology Data Exchange (ETDEWEB)

    Pyatilova, O. V., E-mail: 5ilova87@gmail.com; Gavrilov, S. A.; Shilyaeva, Yu. I. [Zelenograd, National Research University of Electronic Technology (MIET) (Russian Federation); Pavlov, A. A. [Russian Academy of Sciences, Institute of Nanotechnology of Microelectronics (Russian Federation); Shaman, Yu. P. [Zelenograd, Scientific-Manufacturing Complex “Technological Centre” MIET (Russian Federation); Dudin, A. A. [Russian Academy of Sciences, Institute of Nanotechnology of Microelectronics (Russian Federation)

    2017-02-15

    The formation of porous silicon (por-Si) layers by the galvanic etching of single-crystal Si samples (doped with boron or phosphorus) in an HF/C{sub 2}H{sub 5}OH/H{sub 2}O{sub 2} solution is investigated. The por-Si layers are analyzed by the capillary condensation of nitrogen and scanning electron microscopy (SEM). The dependences of the morphological characteristics of por-Si (pore diameter, specific surface area, pore volume, and thickness of the pore walls), which determine the por-Si combustion kinetics, on the dopant type and initial wafer resistivity are established.

  9. Influence of substrate temperature on the electronic and optical properties of Cr doped TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Sen, Sagar; Gupta, Ratnesh, E-mail: gratnesh-ioi@yahoo.com [School of Instrumentation, Devi Ahilya University, Khandwa Road, Indore-452001 (India); Gupta, M. [UGC-DAE CSR Indore Centre, Indore 452 001 (India)

    2016-05-23

    We report the effects of substrate temperature on electrical and optical properties of the Cr-doped TiO{sub 2} film by pulsed laser deposition on Si(100). X-ray reflectivity pattern suggest that the single layer film have been deposited. Total thickness of 86 nm have been obtained. UV-Vis reflectance technique has been used to obtain its optical properties. From the Tauc plot, the bandgap for the film deposited at 150°C is higher compared to the film deposited at lower temperature.

  10. Formation of N{sub 2} during the fixed-bed pyrolysis of coals

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Zhiheng; Ohtsuka, Yasuo [Tohoku Univ., Sendai (Japan); Furimsky, E. [Natural Resources Canada, Ottawa, Ontario (Canada)

    1995-12-31

    Research on the fate of the nitrogen in coal during pyrolysis has attracted increased attention, since it is related with the NO{sub x} and N{sub 2}O emissions during subsequent combustion. It has been reported that coal nitrogen is initially released as tar, which is then converted to HCN and NH{sub 3} through secondary decomposition reactions. However, little attention to N{sub 2} has been paid so far. We have recently found that N{sub 2} is the dominant product in slow heating rate pyrolysis of a subbituminous coal, and that the finely dispersed iron catalyst promotes drastically the formation of N{sub 2} from a brown coal. If coal nitrogen can be removed efficiently as N{sub 2} during pyrolysis, this method would contribute to the reduction of the NO{sub x} and N{sub 2}O emissions, since such pollutants originate mostly from coal nitrogen. Therefore the present study aims at making clear the influence of coal type, pyrolysis conditions, demineralization, and iron catalyst on the formation of N{sub 2} during the fix-bed pyrolysis of several coals with different ranks.

  11. Experimental and Chemical Kinetic Modeling Study of Dimethylcyclohexane Oxidation and Pyrolysis

    KAUST Repository

    Eldeeb, Mazen A.

    2016-08-30

    A combined experimental and chemical kinetic modeling study of the high-temperature ignition and pyrolysis of 1,3-dimethylcyclohexane (13DMCH) is presented. Ignition delay times are measured behind reflected shock waves over a temperature range of 1049–1544 K and pressures of 3.0–12 atm. Pyrolysis is investigated at average pressures of 4.0 atm at temperatures of 1238, 1302, and 1406 K. By means of mid-infrared direct laser absorption at 3.39 μm, fuel concentration time histories are measured under ignition and pyrolytic conditions. A detailed chemical kinetic model for 13DMCH combustion is developed. Ignition measurements show that the ignition delay times of 13DMCH are longer than those of its isomer, ethylcyclohexane. The proposed chemical kinetic model predicts reasonably well the effects of equivalence ratio and pressure, with overall good agreement between predicted and measured ignition delay times, except at low dilution levels and high pressures. Simulated fuel concentration profiles agree reasonably well with the measured profiles, and both highlight the influence of pyrolysis on the overall ignition kinetics at high temperatures. Sensitivity and reaction pathway analyses provide further insight into the kinetic processes controlling ignition and pyrolysis. The work contributes toward improved understanding and modeling of the oxidation and pyrolysis kinetics of cycloalkanes.

  12. Factors affecting the yield of bio-oil from the pyrolysis of coconut shell.

    Science.gov (United States)

    Gao, Yun; Yang, Yi; Qin, Zhanbin; Sun, Yi

    2016-01-01

    Coconut is a high-quality agricultural product of the Asia-Pacific region. In this paper, coconut shell which mainly composed of cellulose, hemicellulose, lignin was used as a raw material for coconut shell oil from coconut shell pyrolysis. The influence of the pyrolysis temperature, heating rate and particle size on coconut oil yield was investigated, and the effect of heating rate on coconut oil components was discussed. Experimental results show that the maximum oil yield of 75.74 wt% (including water) were obtained under the conditions that the final pyrolysis temperature 575 °C, heating rate 20 °C/min, coconut shell diameter about 5 mm. Thermal gravimetric analysis was used and it can be seen that coconut shell pyrolysis process can be divided into three stages: water loss, pyrolysis and pyrocondensation. The main components of coconut-shell oil are water (about 50 wt%), aromatic, phenolic, acid, ketone and ether containing compounds.

  13. Pyrolysis Kinetic Modelling of Wheat Straw from the Pannonian Region

    Directory of Open Access Journals (Sweden)

    Ivan Pešenjanski

    2016-01-01

    Full Text Available The pyrolysis/devolatilization is a basic step of thermochemical processes and requires fundamental characterization. In this paper, the kinetic model of pyrolysis is specified as a one-step global reaction. This type of reaction is used to describe the thermal degradation of wheat straw samples by measuring rates of mass loss of solid matter at a linear increase in temperature. The mentioned experiments were carried out using a derivatograph in an open-air environment. The influence of different factors was investigated, such as particle size, humidity levels, and the heating rate in the kinetics of devolatilization. As the measured values of mass loss and temperature functions transform in Arrhenius coordinates, the results are shown in the form of saddle curves. Such characteristics cannot be approximated with one equation in the form of Arrhenius law. For use in numerical applications, transformed functions can be approximated by linear regression for three separate intervals. Analysis of measurement resulting in granulation and moisture content variations shows that these factors have no significant influence. Tests of heating rate variations confirm the significance of this impact, especially in warmer regions. The influence of this factor should be more precisely investigated as a general variable, which should be the topic of further experiments.

  14. Thermodynamic Model for Updraft Gasifier with External Recirculation of Pyrolysis Gas

    Directory of Open Access Journals (Sweden)

    Fajri Vidian

    2016-01-01

    Full Text Available Most of the thermodynamic modeling of gasification for updraft gasifier uses one process of decomposition (decomposition of fuel. In the present study, a thermodynamic model which uses two processes of decomposition (decomposition of fuel and char is used. The model is implemented in modification of updraft gasifier with external recirculation of pyrolysis gas to the combustion zone and the gas flowing out from the side stream (reduction zone in the updraft gasifier. The goal of the model obtains the influences of amount of recirculation pyrolysis gas fraction to combustion zone on combustible gas and tar. The significant results of modification updraft are that the increases amount of recirculation of pyrolysis gas will increase the composition of H2 and reduce the composition of tar; then the composition of CO and CH4 is dependent on equivalence ratio. The results of the model for combustible gas composition are compared with previous study.

  15. Indium oxide deposition on glass by aerosol pyrolysis (Pyrosol (R) process)

    International Nuclear Information System (INIS)

    Blandenet, G.; Lagarde, Y.; Spitz, J.

    1975-01-01

    The pyrosol (R) process involves the pyrolysis of an aerosol generated by ultrasonic nebulisation from a solution of organic or inorganic compounds. This technique was used to deposit transparent n-conducting indium oxide films on glass. The electrical and optical properties of these films were studied as a function of the deposition temperature and doping (using tin or fluorine). A deposition temperature of 480 deg C and a Sn/In ratio of about 5% gave the best results. In this case, the transmission in the visible range was 92%, the infrared reflection 84% and the electrical resistivity 1.7x10 -4 ohm.cm [fr

  16. Influence of cobalt doping on structural and magnetic properties of BiFeO{sub 3} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Khan, U. [Chinese Academy of Sciences, Institute of Physics (China); Adeela, N., E-mail: adeela16@gmail.com [Centre for High Energy Physics, University of the Punjab (Pakistan); Javed, K. [Chinese Academy of Sciences, Institute of Physics (China); Riaz, S. [Centre for Solid State Physics, University of the Punjab (Pakistan); Ali, H. [Chinese Academy of Sciences, Institute of Physics (China); Iqbal, M. [Centre for High Energy Physics, University of the Punjab (Pakistan); Han, X. F. [Chinese Academy of Sciences, Institute of Physics (China); Naseem, S., E-mail: shahzad-naseem@yahoo.com [Centre for Solid State Physics, University of the Punjab (Pakistan)

    2015-11-15

    Nanocrystalline cobalt-doped bismuth ferrites with general formula of BiFe{sub 1−δ}Co{sub δ}O{sub 3} (0 ≤ δ ≤ 0.1) have been synthesized using solution evaporation method. Structure and phase identification was performed with X-ray diffraction (XRD) technique. The results confirm the formation of rhombohedral-distorted Perovskite structure with R3c symmetry. A decrease in lattice parameters and an increase in X-ray density have been observed with increasing cobalt concentration in BiFeO{sub 3}. Particle size determined by transmission electron microscope was in good agreement with XRD, i.e., 39 nm. Room-temperature coercivity and saturation magnetization of nanoparticles were increased up to 7.5 % of cobalt doping. Low-temperature magnetic measurements of selected sample showed increasing behavior in saturation magnetization, coercivity, effective magnetic moments, and anisotropy constant. An increase in coercivity with decrease in temperature followed theoretical model of Kneller’s law, while modified Bloch’s model was employed for saturation magnetization in temperature range of 5–300 K.Graphical Abstract.

  17. Doped barium titanate nanoparticles

    Indian Academy of Sciences (India)

    Wintec

    nese doped BaTiO3 ceramics, sintered at 1400°C in air, changes from tetragonal to hexagonal between 0⋅5 and. 1⋅7 mole% of manganese (Langhammer et al 2000). As a driving force of the transformation from the cubic to the hexagonal crystal structure, the influence of the Jahn–. Teller distortion is proposed. The grain ...

  18. The influence of electron irradiation at the various temperatures and annealing on carriers mobility at the low temperatures in neutron transmutation doped gallium arsenide

    International Nuclear Information System (INIS)

    Korshunov, F.P.; Kurilovich, N.F.; Prokhorenko, T.A.; Troshchinskii, V.T.; Shesholko, V.K.

    1999-01-01

    The influence of electron irradiation at the various temperatures and annealing on measured at T=100 K carriers mobility in neutron transmutation doped GaAs have been investigated. It was detected that rate of mobility decreasing with irradiation dose increasing decreases when irradiation temperature increases. It was shown that at the same time it take place the radiation defects creating and their particular or full annealing (in the dependence on irradiation temperature). Radiation stimulated annealing (annealing that take place during irradiation at the elevated temperatures) is more effective than the annealing at the same temperatures that take place after crystals are irradiated at room temperature. It means that any defects annealing during irradiation at elevated temperatures take place at more low temperatures than that during annealing after irradiation at room temperature

  19. Pyrolysis of Medium Density Fiberboard (MDF) wastes in a screw reactor

    International Nuclear Information System (INIS)

    Ferreira, Suelem Daiane; Altafini, Carlos Roberto; Perondi, Daniele; Godinho, Marcelo

    2015-01-01

    Highlights: • Medium Density Fiberboard wastes were pirolized in an auger reactor. • Experiments were carried out at two reaction temperatures and three solid residence times. • Yields were influenced by pyrolysis temperature, as well as by solid residence time. • Higher temperature produced more bio-oil rather than char generation. • Chars superficial area were compatibles with those of commercial activated carbons. - Abstract: Medium Density Fiberboard (MDF) wastes were undergoes via a thermal treatment through of a pyrolysis process. Pyrolysis was carried out in a pilot scale reactor with screw conveyor at two reaction temperatures (450 and 600 °C) and, for each one, three solid residence times (9, 15 and 34 min) were evaluated. Products (char/bio-oil/fuel gas) of the pyrolysis process were characterized and quantified. Results revealed that the products yields were influenced by pyrolysis temperature, as well as by solid residence time. Char yield ranged between 17.3 and 39.7 (wt.%), the bio-oil yield ranged between 23.9 and 40.0 (wt.%), while the fuel gas yield ranged between 34.6 and 50.7 (wt.%). The samples surface area at 450 and 600 °C in 15-min residence time were surprisingly high, 415 and 593 m 2 g −1 , respectively, which are compatible with the superficial area of commercial activated carbons. Energetic efficiency of process was estimated from energetic content present in the reaction products and the energetic content of MDF wastes, and the following results were obtained: 41.4% (fuel gas), 35.5% (char) and 29.2% (bio-oil). The contribution of this work is the development of a detailed study of the MDF pyrolysis in a pilot reactor with screw conveyor that supports the biorefineries concept

  20. On single doping and co-doping of spray pyrolysed ZnO films: Structural, electrical and optical characterisation

    International Nuclear Information System (INIS)

    Vimalkumar, T.V.; Poornima, N.; Jinesh, K.B.; Kartha, C. Sudha; Vijayakumar, K.P.

    2011-01-01

    In this paper we present studies on ZnO thin films (prepared using Chemical Spray pyrolysis (CSP) technique) doped in two different ways; in one set, 'single doping' using indium was done while in the second set, 'co-doping' using indium and fluorine was adopted. In the former case, effect of in-situ as well as ex-situ doping using In was analyzed. Structural (XRD studies), electrical (I-V measurements) and optical characterizations (through absorption, transmission and photoluminescence studies) of the films were done. XRD analysis showed that, for spray-deposited ZnO films, ex-situ doping using Indium resulted in preferred (0 0 2) plane orientation, while in-situ doping caused preferred orientation along (1 0 0), (0 0 2), (1 0 1) planes; however for higher percentage of in-situ doping, orientation of grains changed from (0 0 2) plane to (1 0 1) plane. The co-doped films had (0 0 2) and (1 0 1) planes. Lowest resistivity (2 x 10 -3 Ω cm) was achieved for the films, doped with 1% Indium through in-situ method. Photoluminescence (PL) emissions of ex-situ doped and co-doped samples had two peaks; one was the 'near band edge' emission (NBE) and the other was the 'blue-green' emission. But interestingly the PL emission of in-situ doped samples exhibited only the 'near band edge' emission. Optical band gap of the films increased with doping percentage, in all cases of doping.

  1. Slow and pressurized co-pyrolysis of coal and agricultural residues

    International Nuclear Information System (INIS)

    Aboyade, Akinwale O.; Carrier, Marion; Meyer, Edson L.; Knoetze, Hansie; Görgens, Johann F.

    2013-01-01

    Highlights: ► Evaluation of co-pyrolysis of coal and biomass in pressurized packed bed reactor. ► Relative influence of coal–biomass mix ratio, temperature and pressure also investigated. ► Results show significant synergy or chemical interactions in the vapor phase. ► Synergistic interactions did not influence distribution of lumped solid liquid and gas products. - Abstract: The distribution of products from the slow heating rate pyrolysis of coal, corn residues (cobs and stover), sugarcane bagasse and their blends were investigated by slow pressurized pyrolysis in a packed bed reactor. A factorial experimental design was implemented to establish the relative significance of coal–biomass mix ratio, temperature and pressure on product distribution. Results showed that the yield and composition of tar and other volatile products were mostly influenced by mix ratio, while temperature and pressure had a low to negligible significance under the range of conditions investigated. Analysis of the composition of condensates and gas products obtained showed that there was significant synergy or chemical interactions in the vapor phase during co-pyrolysis of coal and biomass. However, the interactions did not significantly affect the relative distribution of the lumped solid, liquid and gas products obtained from the blends, beyond what would be expected assuming additive behavior from the contributing fuels.

  2. Influence of nitrogen-doping concentration on the electronic structure of CuAlO{sub 2} by first-principles studies

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wei-wei, E-mail: zmliuwwliu@126.com; Chen, Hong-xia; Liu, Cheng-lin; Wang, Rong

    2017-02-05

    Effect of N doping concentration on the electronic structure of N-doped CuAlO{sub 2} was investigated by density functional theory based on generalized-gradient approximation plus orbital potential. Lattice parameters a and c both increase with increasing N-doping concentration. Formation energies increase with increasing N doping concentration and all N-doped CuAlO{sub 2} were structurally stable. The calculated band gaps for N-doped CuAlO{sub 2} narrowed compared to pure CuAlO{sub 2}, which was attributed to the stronger hybridization between Cu-3d and N-2p states and the downward shift of Cu-3p states in conduction bands. The higher the N-doping concentration is, the narrower the band gap. N-doped CuAlO{sub 2} shows a typical p-type semiconductor. The band structure changed from indirect to direct after N doping which will benefit the application of the CuAlO{sub 2} materials in optoelectronic and electronic devices. - Highlights: • Electronic structures of CuAlO{sub 2} with different N content were investigated. • The higher the N-doping concentration is, the narrower the band gap. • All the CuAlO{sub 2} with different N content were structurally stable. • The N-doped CuAlO{sub 2} shows a typical p-type semiconductor characteristic.

  3. Catalytic pyrolysis using UZM-39 aluminosilicate zeolite

    Science.gov (United States)

    Nicholas, Christpher P; Boldingh, Edwin P

    2013-12-17

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

  4. Photocatalytic Desulfurization of Waste Tire Pyrolysis Oil

    Directory of Open Access Journals (Sweden)

    Napida Hinchiranan

    2011-11-01

    Full Text Available Waste tire pyrolysis oil has high potential to replace conventional fossil liquid fuels due to its high calorific heating value. However, the large amounts of sulfurous compounds in this oil hinders its application. Thus, the aim of this research was to investigate the possibility to apply the photo-assisted oxidation catalyzed by titanium dioxide (TiO2, Degussa P-25 to partially remove sulfurous compounds in the waste tire pyrolysis oil under milder reaction conditions without hydrogen consumption. A waste tire pyrolysis oil with 0.84% (w/w of sulfurous content containing suspended TiO2 was irradiated by using a high-pressure mercury lamp for 7 h. The oxidized sulfur compounds were then migrated into the solvent-extraction phase. A maximum % sulfur removal of 43.6% was achieved when 7 g/L of TiO2 was loaded into a 1/4 (v/v mixture of pyrolysis waste tire oil/acetonitrile at 50 °C in the presence of air. Chromatographic analysis confirmed that the photo-oxidized sulfurous compounds presented in the waste tire pyrolysis oil had higher polarity, which were readily dissolved and separated in distilled water. The properties of the photoxidized product were also reported and compared to those of crude oil.

  5. Coal pyrolysis under hydrogen-rich gases

    Energy Technology Data Exchange (ETDEWEB)

    Liao, H.; Sun, C.; Li, B.; Liu, Z. [Chinese Academy of Sciences, Taiyuan (China). State Key Laboratory of Coal Conversion, Institute of Coal Chemistry

    1998-04-01

    To improve the economy of the pyrolysis process by reducing the hydrogen cost, it is suggested to use cheaper hydrogen-rich gases such as coke-oven gas (COG) or synthesis gas (SG) instead of pure hydrogen. The pyrolysis of Chinese Xianfeng lignite which was carried out with real COG and SG at 3-5 MPa, a final temperature of 650{degree}C and a heating rate of 5{degree}C/min in a 10g fixed-bed reactor is compared with coal pyrolysis with pure hydrogen and nitrogen under the same conditions. The results indicate that compared with hydropyrolysis at the same total pressure, the total conversion and tar yields from coal pyrolysis with COG and SG decreases while the unwanted water increases. However, at the same H{sub 2} partial pressure, the tar yields and yields of BBTX, PCX and naphthalene from the pyrolysis of coal with COG and SG are all significantly higher than those of hydropyrolysis. Therefore, it is possible to use COG and SG instead of pure hydrogen. 8 refs., 3 figs., 6 tabs.

  6. Pyrolysis characteristics and pyrolysis products separation for recycling organic materials from waste liquid crystal display panels

    International Nuclear Information System (INIS)

    Wang, Ruixue; Xu, Zhenming

    2016-01-01

    Highlights: • Pyrolysis characteristics are conducted for a better understanding of LCDs pyrolysis. • Optimum design is developed which is significant to guide the further industrial process. • Acetic acid and TPP are recycled and separated. - Abstract: Waste liquid crystal display (LCD) panels mainly contain inorganic materials (glass substrate with indium-tin oxide film), and organic materials (polarizing film and liquid crystal). The organic materials should be removed beforehand since the organic matters would hinder the indium recycling process. In the present study, pyrolysis process is used to remove the organic materials and recycle acetic as well as and triphenyl phosphate (TPP) from waste LCD panels in an environmental friendly way. Several highlights of this study are summarized as follows: (i) Pyrolysis characteristics and pyrolysis kinetics analysis are conducted which is significant to get a better understanding of the pyrolysis process. (ii) Optimum design is developed by applying Box–Behnken Design (BBD) under response surface methodology (RSM) for engineering application which is significant to guide the further industrial recycling process. The oil yield could reach 70.53 wt% and the residue rate could reach 14.05 wt% when the pyrolysis temperature is 570 °C, nitrogen flow rate is 6 L min"−"1 and the particle size is 0.5 mm. (iii) Furthermore, acetic acid and TPP are recycled, and then separated by rotary evaporation, which could reduce the consumption of fossil energy for producing acetic acid, and be reused in electronics manufacturing industry.

  7. Pyrolysis characteristics and pyrolysis products separation for recycling organic materials from waste liquid crystal display panels

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ruixue; Xu, Zhenming, E-mail: zmxu@sjtu.edu.cn

    2016-01-25

    Highlights: • Pyrolysis characteristics are conducted for a better understanding of LCDs pyrolysis. • Optimum design is developed which is significant to guide the further industrial process. • Acetic acid and TPP are recycled and separated. - Abstract: Waste liquid crystal display (LCD) panels mainly contain inorganic materials (glass substrate with indium-tin oxide film), and organic materials (polarizing film and liquid crystal). The organic materials should be removed beforehand since the organic matters would hinder the indium recycling process. In the present study, pyrolysis process is used to remove the organic materials and recycle acetic as well as and triphenyl phosphate (TPP) from waste LCD panels in an environmental friendly way. Several highlights of this study are summarized as follows: (i) Pyrolysis characteristics and pyrolysis kinetics analysis are conducted which is significant to get a better understanding of the pyrolysis process. (ii) Optimum design is developed by applying Box–Behnken Design (BBD) under response surface methodology (RSM) for engineering application which is significant to guide the further industrial recycling process. The oil yield could reach 70.53 wt% and the residue rate could reach 14.05 wt% when the pyrolysis temperature is 570 °C, nitrogen flow rate is 6 L min{sup −1} and the particle size is 0.5 mm. (iii) Furthermore, acetic acid and TPP are recycled, and then separated by rotary evaporation, which could reduce the consumption of fossil energy for producing acetic acid, and be reused in electronics manufacturing industry.

  8. Co pyrolysis of biomass and PP

    International Nuclear Information System (INIS)

    Heo, Hyeon Su; Kim, Jung Hwan; Cho, Hye Jung; Ko, Jeong Huy; Park, Hye Jin; Bae, Yoon Ju; Park, Young Kwon

    2010-01-01

    Full text: While bio-oil has received considerable attention both as a source of energy and as an organic feedstock, its stability as fuel is very low due to high oxygen content. Therefore, there are many efforts to upgrade it. Among them, co pyrolysis with polyolefin can be a method to obtain stable bio-oil. Because polyolefins contain higher hydrogen and carbon content than biomass and no oxygen, plastic/ biomass co pyrolysis may upgrade the bio-oil properties by increasing the carbon and hydrogen contents while reducing oxygen content. In this study, wood biomass was mixed with PP and then co pyrolysis was carried out in a batch reactor. The produced oil and gas was analyzed using GC and GC-MS. Also elemental analysis was performed to know the hydrogen, carbon and oxygen content of bio-oil. The effect of various reaction conditions on bio-oil properties were presented in detail. (author)

  9. NMR spectroscopy of coal pyrolysis products

    Energy Technology Data Exchange (ETDEWEB)

    Polonov, V.M.; Kalabin, G.A.; Kushnarev, D.F.; Shevchenko, G.G.

    1985-12-01

    The authors consider the scope for using H 1 and C 13 NMR spectroscopy to describe the products from coal pyrolysis and hydrogenization. The accuracy of the structural information provided by the best NMR methods is also considered. The stuctural parameters derived from H 1 and C 13 NMR spectra are presented. Results demonstrate the high accuracy and sensitivity of the structural information provided by H 1 AND C 13 NMR spectra for coal products. There are substantial structural differences between the soluble products from medium-temperature coking of Cheremkhov coal and high-speed pyrolysis of Kan-Acha coal, and also differences in behavior during hydrogenation. These differences are related to the structure of the organic matter in the initial coal and to differences in the pyrolysis mechanisms.

  10. Pyrolysis and volatilization of cocaine

    International Nuclear Information System (INIS)

    Martin, B.R.; Lue, L.P.; Boni, J.P.

    1989-01-01

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

  11. Reaction rate of propene pyrolysis.

    Science.gov (United States)

    Han, Peipei; Su, Kehe; Liu, Yan; Wang, Yanli; Wang, Xin; Zeng, Qingfeng; Cheng, Laifei; Zhang, Litong

    2011-10-01

    The reaction rate of propene pyrolysis was investigated based on the elementary reactions proposed in Qu et al., J Comput Chem 2009, 31, 1421. The overall reaction rate was developed with the steady-state approximation and the rate constants of the elementary reactions were determined with the variational transition state theory. For the elementary reaction having transition state, the vibrational frequencies of the selected points along the minimum energy path were calculated with density functional theory at B3PW91/6-311G(d,p) level and the energies were improved with the accurate model chemistry method G3(MP2). For the elementary reaction without transition state, the frequencies were calculated with CASSCF/6-311G(d,p) and the energies were refined with the multireference configuration interaction method MRCISD/6-311G(d,p). The rate constants were evaluated within 200-2000 K and the fitted three-parameter expressions were obtained. The results are consistent with those in the literatures in most cases. For the overall rate, it was found that the logarithm of the rate and the reciprocal temperature have excellent linear relationship above 400 K, predicting that the rate follows a typical first-order law at high temperatures of 800-2000 K, which is also consistent with the experiments. The apparent activation energy in 800-2000 K is 317.3 kJ/mol from the potential energy surface of zero Kelvin. This value is comparable with the energy barriers, 365.4 and 403.7 kJ/mol, of the rate control steps. However, the apparent activation energy, 215.7 kJ/mol, developed with the Gibbs free energy surface at 1200 K is consistent with the most recent experimental result 201.9 ± 0.6 kJ/mol. Copyright © 2011 Wiley Periodicals, Inc.

  12. High performance electrodes for reduced temperature solid oxide fuel cells with doped lanthanum gallate electrolyte. I. Ni-SDC cermet anode

    Science.gov (United States)

    Ohara, S.; Maric, R.; Zhang, X.; Mukai, K.; Fukui, T.; Yoshida, H.; Inagaki, T.; Miura, K.

    A Ni-samaria-doped ceria (SDC) cermet was selected as the anode material for reduced temperature (800°C) solid oxide fuel cells. The NiO-SDC composite powder, synthesized by spray pyrolysis, was employed as the starting anode powder in this study. The influence of Ni content in Ni-SDC cermets on the electrode performance was investigated in order to create the most suitable microstructures. It was found that anodic polarization was strongly influenced by the Ni content in Ni-SDC cermets. The best results were obtained for anode cermets with Ni content of around 50 vol.%; anodic polarization was about 30 mV at a current density of 300 mA/cm 2. This high performance seems to be attributable to the microstructure, in which Ni grains form a skeleton with well-connected SDC grains finely distributed over the Ni grains surfaces; such microstructure was also conducive to high stability of the anode.

  13. High performance electrodes for reduced temperature solide oxide fuel cells with doped lanthanum gallate electrolyte. Pt. 1. Ni-SDC cermet anode

    Energy Technology Data Exchange (ETDEWEB)

    Ohara, S.; Maric, R.; Zhang, X.; Mukai, K.; Fukui, T. [Japan Fine Ceramics Center, Nagoya (Japan); Yoshida, H.; Inagaki, T. [The Kansai Electroc Power Co. Inc., Hyogo (Japan); Miura, K. [Kanden Kakou Co. Ltd., Hyogo (Japan)

    2000-03-01

    A Ni-samaria-doped ceria (SDC) cermet was selected as the anode material for reduced temperature (800 C) solid oxide fuel cells. The NiO-SDC composite powder, synthesized by spray pyrolysis, was employed as the starting anode powder in this study. The influence of Ni content in Ni-SDC cermets on the electrode performance was investigated in order to create the most suitable microstructures. It was found that anodic polarization was strongly influenced by the Ni content in Ni-SDC cermets. The best results were obtained for anode cermets with Ni content of around 50 vol.%; anodic polarization was about 30 mV at a current density of 300 mA/cm{sup 2}. This high performance seems to be attributable to the microstructure, in which Ni grains form a skeleton with well-connected SDC grains finely distributed over the Ni grains surfaces; such microstructure was also conducive to high stability of the anode. (orig.)

  14. Waste truck-tyre processing by flash pyrolysis in a conical spouted bed reactor

    International Nuclear Information System (INIS)

    Lopez, G.; Alvarez, J.; Amutio, M.; Mkhize, N.M.; Danon, B.; Gryp, P.; Görgens, J.F. van der; Bilbao, J.; Olazar, M.

    2017-01-01

    Highlights: • Flash pyrolysis improves TPO and limonene yields vs. slow pyrolysis. • The most suitable temperature for TPO and limonene maximization was 475 °C. • Operating at 575 °C gas yields and char quality was enhanced. • Temperature showed a limited effect on sulphur distribution among products. - Abstract: The flash pyrolysis of waste truck-tyres was studied in a conical spouted bed reactor (CSBR) operating in continuous regime. The influence of temperature on product distribution was analysed in the 425–575 °C range. A detailed characterization of the pyrolysis products was carried out in order to assess their most feasible application. Moreover, special attention was paid to the sulphur distribution among the products. The analysis of gaseous products was carried out using a micro-GC and the tyre pyrolysis oil (TPO) by means of GC-FID using peak areas for quantification, with GC/MS for identification and elemental analysis. Finally, the char was subjected to elemental analysis and surface characterization. According to the results, 475 °C is an appropriate temperature for the pyrolysis of waste tyres, given that it ensures total devolatilisation of tyre rubber and a high TPO yield, 58.2 wt.%. Moreover, the quality of the oil is optimum at this temperature, especially in terms of high concentrations of valuable chemicals, such as limonene. An increase in temperature to 575 °C reduced the TPO yield to 53.9 wt.% and substantially changed its chemical composition by increasing the aromatic content. However, the quality of the recovered char was improved at high temperatures.

  15. Pyrolysis of Pine Wood, Experiments and Theory

    DEFF Research Database (Denmark)

    Fjellerup, Jan Søren; Ahrenfeldt, Jesper; Henriksen, Ulrik Birk

    In this study, pinewood has been pyrolyzed using a fixed heating rate with a variable end-temperature. The pyrolysis process has been simulated using a mechanism with three parallel reactions for the formation of char, gas and tar. First order irreversible kinetics is assumed. This kind of model...... may predict the variation of product yield with operating conditions such as temperature and heating rate. The system of coupled differential equations describing the pyrolysis process is solved using the software DYMOLA. Various literature values for kinetic parameters have been compared...

  16. PYROLYSIS OF ZINC CONTAMINATED BIOMASS FROM PHYTOREMEDIATION

    OpenAIRE

    Özkan, Aysun; Günkaya, Zerrin; Banar, Müfide; Kulaç, Alev; Yalçın, Gülser; Taşpınar, Kadriye; Altay, Abdullah

    2015-01-01

    The objective of this study was to stabilize of zinc (Zn) from soil to pyrolysis solid product. For this aim, phytoremediation and pyrolysis were sequentially applied. In the first stage of the study, phytoremediation was first applied to zinc contaminated soil via  sunflower (Helianthus annuus), corn (Zea mays) and rape (Brassica napus), After harvesting, the plants were pyrolyzed at 500°C with the heating rate of 35 °C/min in a fixed bed stainless steel (380 S) 240 cm3 reactor. The phytorem...

  17. Survival of Salmonella, Escherichia coli 0157:H7, non-0157 shiga toxin producing E.coli, and potential surrogate bacteria in crop soil as affected by the addition of fast pyrolysis-generated switchgrass biochar

    Science.gov (United States)

    Fast pyrolysis of switchgrass (and resultant biochar) can be used for bio-fuel production, soil amendments for fertilizing crops, binding heavy metals, and sequestering environmental biocarbon. To determine the influence of fast pyrolysis-generated switchgrass biochar on survival of foodborne path...

  18. Structural and optical properties of Zn doped CuInS 2 thin films

    Indian Academy of Sciences (India)

    Copper indium sulphide (CIS) films were deposited by spray pyrolysis onto glass ... The effects of Zn (0–5%)molecular weight compared with CuInS2 Source and ... candidates for use as doped acceptors to fabricate CuInS2-based solar cells.

  19. Regional differences in the economic feasibility of advanced biorefineries: Fast pyrolysis and hydroprocessing

    International Nuclear Information System (INIS)

    Brown, Tristan R.; Thilakaratne, Rajeeva; Brown, Robert C.; Hu, Guiping

    2013-01-01

    This analysis identifies the sensitivity of the fast pyrolysis and hydroprocessing pathway to facility location. The economic feasibility of a 2000 metric ton per day fast pyrolysis and hydroprocessing biorefinery is quantified based on 30 different state-specific facility locations within the United States. We calculate the 20-year internal rate of return (IRR) and net present value (NPV) for each location scenario as a function of state- and region-specific factors. This analysis demonstrates that biorefinery IRR and NPV are very sensitive to bio-oil yield, feedstock cost, location capital cost factor, and transportation fuel market value. The IRRs and NPVs generated for each scenario vary widely as a result, ranging from a low of 7.4% and −$79.5 million in Illinois to a high of 17.2% and $165.5 million in Georgia. The results indicate that the economic feasibility of the fast pyrolysis and hydroprocessing pathway is strongly influenced by facility location within the United States. This result could have important implications for cellulosic biofuel commercialization under the revised Renewable Fuel Standard. - Highlights: ► We model the production of biofuel via fast pyrolysis and hydroprocessing of biomass. ► We compile regional- and state-specific factors for 30 different US state scenarios. ► We quantify facility economic feasibility under each state scenario. ► Facility economic feasibility is strongly influenced by facility location

  20. Cu2+, Co2+ and Cr3+ doping of a calcium phosphate cement influences materials properties and response of human mesenchymal stromal cells.

    Science.gov (United States)

    Schamel, Martha; Bernhardt, Anne; Quade, Mandy; Würkner, Claudia; Gbureck, Uwe; Moseke, Claus; Gelinsky, Michael; Lode, Anja

    2017-04-01

    The application of biologically active metal ions to stimulate cellular reactions is a promising strategy to accelerate bone defect healing. Brushite-forming calcium phosphate cements were modified with low doses of Cu 2+ , Co 2+ and Cr 3+ . The modified cements released the metal ions in vitro in concentrations which were shown to be non-toxic for cells. The release kinetics correlated with the solubility of the respective metal phosphates: 17-45 wt.-% of Co 2+ and Cu 2+ , but calcium and phosphate ions with cell culture medium. In case of cements modified with 50mmol Cr 3+ /mol β-tricalcium phosphate (β-TCP), XRD and SEM analyses revealed a significant amount of monetite and a changed morphology of the cement matrix. Cell culture experiments with human mesenchymal stromal cells indicated that the observed cell response is not only influenced by the released metal ions but also by changed cement properties. A positive effect of modifications with 50mmol Cr 3+ or 10mmol Cu 2+ per mol β-TCP on cell behaviour was observed in indirect and direct culture. Modification with Co 2+ resulted in a clear suppression of cell proliferation and osteogenic differentiation. In conclusion, metal ion doping of the cement influences cellular activities in addition to the effect of released metal ions by changing properties of the ceramic matrix. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Pyrolysis model for an alpha waste incinerator prototype

    International Nuclear Information System (INIS)

    Orloff, D.I.

    1978-01-01

    The development of a theoretical model of the pyrolysis stage of an SRL prototype alpha waste incinerator is discussed. Pyrolysis rates for single component porous beds of Teflon (Registered trademark of Du Pont) and natural rubber have been measured on a bench-scale furnace. Experimental pyrolysis rates compare favorably to the predictions of a quasi-steady regression model. In addition, the pyrolysis rate is shown to be a weak function of the thermal diffusivity of the porous polymer bed. As a consequence, pyrolysis is controlled by thermal degradation kinetics rather than by diffusion or conduction

  2. Influence of Cobalt Doping on the Physical Properties of Zn0.9Cd0.1S Nanoparticles

    Directory of Open Access Journals (Sweden)

    Gupta Hari Om

    2009-01-01

    Full Text Available Abstract Zn0.9Cd0.1S nanoparticles doped with 0.005–0.24 M cobalt have been prepared by co-precipitation technique in ice bath at 280 K. For the cobalt concentration >0.18 M, XRD pattern shows unidentified phases along with Zn0.9Cd0.1S sphalerite phase. For low cobalt concentration (≤0.05 M particle size, d XRDis ~3.5 nm, while for high cobalt concentration (>0.05 M particle size decreases abruptly (~2 nm as detected by XRD. However, TEM analysis shows the similar particle size (~3.5 nm irrespective of the cobalt concentration. Local strain in the alloyed nanoparticles with cobalt concentration of 0.18 M increases ~46% in comparison to that of 0.05 M. Direct to indirect energy band-gap transition is obtained when cobalt concentration goes beyond 0.05 M. A red shift in energy band gap is also observed for both the cases. Nanoparticles with low cobalt concentrations were found to have paramagnetic nature with no antiferromagnetic coupling. A negative Curie–Weiss temperature of −75 K with antiferromagnetic coupling was obtained for the high cobalt concentration.

  3. Influence of small DC bias field on the electrical behaviour of Sr- and Mg-doped lanthanum gallate

    Science.gov (United States)

    Raghvendra; Singh, Rajesh Kumar; Singh, Prabhakar

    2014-09-01

    One of the promising electrolyte materials for solid oxide fuel cells application, Sr- and Mg-doped lanthanum gallate La0.9Sr0.1Ga0.8Mg0.2O3-δ (LSGM), is synthesized by conventional solid state ceramic route. X-ray Rietveld analysis confirms the formation of main orthorhombic phase at room temperature along with a few minor secondary phases. SEM micrograph reveals the grain and grainboundary morphology of the system. Electrical conductivity of the LSGM sample is measured in the temperature range 573-873 K and in the frequency range 20 Hz-1 MHz at a few small DC bias fields (at 0.0, 0.5, 1.0, 1.5 and 2.0 V). The conductivity spectra show power-law behaviour. Electrical conductivity of the sample is found to be weakly dependent on DC bias field. This is attributed to field-dependent bulk and grainboundary conduction processes. In the present system, under investigated bias field range, the possibility of formation of Schottky barrier is ruled out. The concept of grainboundary channel (pathway) modulation on the application of bias field is proposed.

  4. Influence of small DC bias field on the electrical behaviour of Sr- and Mg-doped lanthanum gallate

    International Nuclear Information System (INIS)

    Raghvendra; Singh, Rajesh Kumar; Singh, Prabhakar

    2014-01-01

    One of the promising electrolyte materials for solid oxide fuel cells application, Sr- and Mg-doped lanthanum gallate La 0.9 Sr 0.1 Ga 0.8 Mg 0.2 O 3-δ (LSGM), is synthesized by conventional solid state ceramic route. X-ray Rietveld analysis confirms the formation of main orthorhombic phase at room temperature along with a few minor secondary phases. SEM micrograph reveals the grain and grainboundary morphology of the system. Electrical conductivity of the LSGM sample is measured in the temperature range 573-873 K and in the frequency range 20 Hz-1 MHz at a few small DC bias fields (at 0.0, 0.5, 1.0, 1.5 and 2.0 V). The conductivity spectra show power-law behaviour. Electrical conductivity of the sample is found to be weakly dependent on DC bias field. This is attributed to field-dependent bulk and grainboundary conduction processes. In the present system, under investigated bias field range, the possibility of formation of Schottky barrier is ruled out. The concept of grainboundary channel (pathway) modulation on the application of bias field is proposed. (orig.)

  5. Influence of small DC bias field on the electrical behaviour of Sr- and Mg-doped lanthanum gallate

    Energy Technology Data Exchange (ETDEWEB)

    Raghvendra; Singh, Rajesh Kumar; Singh, Prabhakar [Indian Institute of Technology (Banaras Hindu University), Department of Physics, Varanasi (India)

    2014-09-15

    One of the promising electrolyte materials for solid oxide fuel cells application, Sr- and Mg-doped lanthanum gallate La{sub 0.9}Sr{sub 0.1}Ga{sub 0.8}Mg{sub 0.2}O{sub 3-δ} (LSGM), is synthesized by conventional solid state ceramic route. X-ray Rietveld analysis confirms the formation of main orthorhombic phase at room temperature along with a few minor secondary phases. SEM micrograph reveals the grain and grainboundary morphology of the system. Electrical conductivity of the LSGM sample is measured in the temperature range 573-873 K and in the frequency range 20 Hz-1 MHz at a few small DC bias fields (at 0.0, 0.5, 1.0, 1.5 and 2.0 V). The conductivity spectra show power-law behaviour. Electrical conductivity of the sample is found to be weakly dependent on DC bias field. This is attributed to field-dependent bulk and grainboundary conduction processes. In the present system, under investigated bias field range, the possibility of formation of Schottky barrier is ruled out. The concept of grainboundary channel (pathway) modulation on the application of bias field is proposed. (orig.)

  6. Influence of silver nanoparticles on the spectroscopic properties of Sm{sup 3+} doped boro-phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Suthanthirakumar, P.; Marimuthu, K., E-mail: emari-ram2000@yahoo.com [Department of Physics, Gandhigram Rural University, Gandhigram - 624 302 (India)

    2016-05-23

    The Sm{sup 3+} doped novel boro-phosphate glasses containing silver nanoparticles (NPs) (SmBPxA) have been prepared following the melt quenching technique and their structural and spectroscopic behavior were studied through HR-TEM, optical absorption and photoluminescence spectral measurements. The TEM analysis validates the existence of Ag NPs with an average diameter of ~8 nm. The Surface plasmon resonance (SPR) band of silver NPs was found at around 600 nm from the absorption spectrum of the Sm{sup 3+} ions free glass sample. The optical band gap energy (E{sub opt}) corresponding to the direct and indirect allowed transitions and the Urbach energy (ΔE) values were determined from the absorption spectral measurements. The luminescence intensity is found to get enhance when the Ag NPs were embedded along with the Sm{sup 3+} ions in the prepared glasses due to the local electric field effect around the rare earth (RE) ion site produced by the SPR of Ag NPs.

  7. The Influence of Doping with Transition Metal Ions on the Structure and Magnetic Properties of Zinc Oxide Thin Films

    Directory of Open Access Journals (Sweden)

    Jenica Neamtu

    2014-01-01

    Full Text Available Zn1−xNixO (x=0.03÷0.10 and Zn1−xFexO (x=0.03÷0.15 thin films were synthesized by sol-gel method. The structure and the surface morphology of zinc oxide thin films doped with transition metal (TM ions have been investigated by X-ray diffraction (XRD and atomic force microscopy (AFM. The magnetic studies were done using vibrating sample magnetometer (VSM at room temperature. Experimental results revealed that the substitution of Ni ions in ZnO wurtzite lattice for the contents x=0.03÷0.10 (Ni2+ leads to weak ferromagnetism of thin films. For Zn1-xFexO with x=0.03÷0.05, the Fe3+ ions are magnetic coupling by superexchange interaction via oxygen ions in wurtzite structure. For x=0.10÷0.15 (Fe3+ one can observe the increasing of secondary phase of ZnFe2O4 spinel. The Zn0.9Fe0.1O film shows a superparamagnetic behavior due to small crystallite sizes and the net spin magnetic moments arisen from the interaction between the iron ions through an oxygen ion in the spinel structure.

  8. Influence of bismuth doping on the structural and optical properties of ZnS thin films and nanopowders

    International Nuclear Information System (INIS)

    Mageswari, S; Palanivel, Balan; Dhivya, L; Murugan, Ramaswamy

    2013-01-01

    Zn (1−x/2) Bi x/3 S (x = 0, 0.03, 0.09) thin films and nanopowders synthesized by the simple chemical bath deposition technique were characterized using x-ray diffraction (XRD), scanning electron microscope, energy dispersive x-ray analysis, an atomic force microscope (AFM) and ultraviolet visible (UV–Vis) and photoluminescence spectroscopy. XRD analysis revealed a sphalerite structure for Zn (1−x/2) Bi x/3 S (x = 0, 0.03, 0.09) thin films. However, the XRD pattern of Zn (1−x/2) Bi x/3 S (x = 0.09) nanopowder revealed the co-existence of both sphalerite and hexagonal (wurtzite) phases. The crystallite size of Zn (1−x/2) Bi x/3 S (x = 0, 0.03, 0.09) nanopowders were found to be in the range of 2–4 nm. AFM studies revealed that the film quality of Zn (1−x/2) Bi x/3 S (x = 0.09) was relatively good compared to other films. A notable decrease in the band gap of both the thin films and nanopowders were observed with incorporation of Bi 3+ in ZnS. These results indicate that Bi doped ZnS can be used to enhance the photocatalytic H 2 -production activity under visible and UV light. (paper)

  9. Influence of heat treatment and oxygen doping on the mechanical properties and biocompatibility of titanium-niobium binary alloys.

    Science.gov (United States)

    da Silva, Luciano Monteiro; Claro, Ana Paula Rosifini Alves; Donato, Tatiani Ayako Goto; Arana-Chavez, Victor E; Moraes, João Carlos Silos; Buzalaf, Marília Afonso Rabelo; Grandini, Carlos Roberto

    2011-05-01

    The most commonly used titanium (Ti)-based alloy for biological applications is Ti-6Al-4V, but some studies associate the vanadium (V) with the cytotoxic effects and adverse reactions in tissues, while aluminum (Al) has been associated with neurological disorders. Ti-Nb alloys belong to a new class of Ti-based alloys with no presence of Al and V and with elasticity modulus values that are very attractive for use as a biomaterial. It is well known that the presence of interstitial elements (such as oxygen, for example) changes the mechanical properties of alloys significantly, particularly the elastic properties, the same way that heat treatments can change the microstructure of these alloys. This article presents the effect of heat treatment and oxygen doping in some mechanical properties and the biocompatibility of three alloys of the Ti-Nb system, characterized by density measurements, X-ray diffraction, optical microscopy, Vickers microhardness, in vitro cytotoxicity, and mechanical spectroscopy. © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  10. The influence of p-doping on two-state lasing in InAs/InGaAs quantum dot lasers

    Science.gov (United States)

    Maximov, M. V.; Shernyakov, Yu M.; Zubov, F. I.; Zhukov, A. E.; Gordeev, N. Yu; Korenev, V. V.; Savelyev, A. V.; Livshits, D. A.

    2013-10-01

    Two-state lasing in devices based on undoped and p-type modulation-doped InAs/InGaAs quantum dots is studied for various cavity lengths and temperatures. Modulation doping of the active region strongly enhances the threshold current of two-state lasing, preserves ground-state lasing up to higher temperatures and increases ground-state output power. The impact of modulation doping is especially strong in short cavities.

  11. The influence of p-doping on two-state lasing in InAs/InGaAs quantum dot lasers

    International Nuclear Information System (INIS)

    Maximov, M V; Shernyakov, Yu M; Zhukov, A E; Gordeev, N Yu; Zubov, F I; Korenev, V V; Savelyev, A V; Livshits, D A

    2013-01-01

    Two-state lasing in devices based on undoped and p-type modulation-doped InAs/InGaAs quantum dots is studied for various cavity lengths and temperatures. Modulation doping of the active region strongly enhances the threshold current of two-state lasing, preserves ground-state lasing up to higher temperatures and increases ground-state output power. The impact of modulation doping is especially strong in short cavities. (paper)

  12. Influence of nitrogen dopants on N-doped TiO2 electrodes and their applications in dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Guo Wei; Shen Yihua; Boschloo, Gerrit; Hagfeldt, Anders; Ma Tingli

    2011-01-01

    Highlights: → Three different types of nanocrystalline N-doped TiO 2 synthesized by several nitrogen dopants. → N-doped DSCs achieves a high conversion efficiency of 8.32%. → Ammonia acts as good nitrogen dopants. → Enhanced photocurrent of ca. 36% in N-doped DSCs. → Less charge are needed to get a high open-circuit voltage in N-doped films. - Abstract: Three different types of nanocrystalline, N-doped TiO 2 electrodes were synthesized using several nitrogen dopants through wet methods. The obtained nanocrystalline, N-doped TiO 2 electrodes possessed different crystallite sizes, surface areas, and N-doping amounts. Characterizations were performed to reveal the nitrogen-doping processes for the wet methods using ammonia, urea, and triethylamine as the nitrogen dopants. Additionally, a high conversion efficiency of 8.32% was achieved by the dye-sensitized solar cells, based on the N-doped TiO 2 electrodes. For instance, in comparison with the commercial P25 (5.76%) and pure anatase TiO 2 electrodes (7.14%), significant improvements (44% and 17%, respectively) in the efficiencies were obtained. The findings also indicated that the ammonia nitrogen dopant was more efficient than other two nitrogen dopants. The electron transports, electron lifetimes, and charge recombination in the dye-sensitized N-doped TiO 2 solar cells also differed from those in the pure TiO 2 -based dye-sensitized solar cells (DSCs). Specifically, an enhanced photocurrent of ca. 36% in N-doped DSCs resulted from the synergistic effects of the high dye uptake and the efficient electron transport. Moreover, the relationship between charge and voltage revealed that less charge was needed to get a high open-circuit voltage in the N-doping films.

  13. Layered growth of aligned carbon nanotube arrays by pyrolysis

    International Nuclear Information System (INIS)

    Zhang Hongrui; Liang Erjun; Ding Pei; Chao Mingju

    2003-01-01

    Based on the study of reaction temperature and duration of the growth of aligned carbon nanotube arrays, layered aligned multi-wall carbon nanotube (MWNT) films grown directly around a reaction quartz tube in an Ar/H 2 atmosphere by pyrolysis of ferrocene in xylene in a suitable reaction furnace with the help of cobalt powder. The scanning electron microscope and transmission electron microscope images indicated that the obtained arrays were composed of many separated layers with MWNTs. The reaction temperature significantly influenced the alignment of the MWNTs, and an appropriate reaction temperature range for growth was 800-900 deg. C. The diameter of the carbon nanotube increased from 46 to 75 nm with the growth temperature. Besides temperature, the reaction duration influenced the length of the well-aligned carbon nanotubes. There was no significant relation between the growth time and the diameter of the carbon nanotubes in the array

  14. ZnO layers prepared by spray pyrolysis

    Science.gov (United States)

    Messaoudi, C.; Abd-Lefdil, S.; Sayah, D.; Cadene, M.

    1998-02-01

    Highly transparent undoped and indium doped ZnO thin films have been grown on glass substrates by using the spray pyrolysis process. Conditions of preparation have been optimized to get good quality and reproducible films with required properties. Polycrystalline films with an hexagonal Wurtzite-type structure were easily obtained under the optimum spraying conditions. Both of samples have shown high transmission coefficient in the visible and infrared wavelength range with sharp absorption edge around 380 nm which closely corresponds to the intrinsic band-gap of ZnO (3.2 eV). Orientation and crystallites size were remarkably modified by deposition temperature and indium doping. Des couches minces de ZnO, hautement transparentes, non dopées et dopées à l'indium ont été élaborées sur un substrat en verre par le procédé de pulvérisation chimique réactive spray. Les conditions de préparation ont été optimisées pour l'obtention de couches reproductibles, de bonne qualité et ayant les propriétés requises. Des films polycristallins, présentant une structure hexagonale de type Wurtzite, ont été aisément obtenus dans les conditions optimales de pulvérisation. Tous les échantillons ont présenté un coefficient de transmission élevé dans le domaine du visible et du proche infrarouge, avec une absorption brutale au voisinage de 380 nm, correspondant au gap optique du ZnO (3,2 eV). L'orientation et la taille des cristallites ont été remarquablement modifiées par la température du dépôt et par le dopage à l'indium.

  15. The lignin pyrolysis composition and pyrolysis products of palm kernel shell, wheat straw, and pine sawdust

    International Nuclear Information System (INIS)

    Chang, Guozhang; Huang, Yanqin; Xie, Jianjun; Yang, Huikai; Liu, Huacai; Yin, Xiuli; Wu, Chuangzhi

    2016-01-01

    Highlights: • The primarily pyrolysis composition of PKS lignin was p-hydroxyphenyl unit. • Higher phenol yield and lower gas energy yield were obtained from PKS pyrolysis. • PKS produced more bio-oil and biochar than WS and PS from pyrolysis at 650–850 °C. • PKS-char had poorer gasification reactivity due to higher ordering carbon degree. - Abstract: The lignin monomer composition of palm kernel shell (PKS) was characterized using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), and the characteristics and distributions of products obtained from PKS pyrolysis were investigated using Py-GC/MS, GC, and a specially designed pyrolysis apparatus. The gasification reactivity of PKS biochar was also characterized using thermogravimetry (TG) and Raman spectroscopy. All the results were compared with those obtained from wheat straw (WS) and pine sawdust (PS). The results showed that PKS lignin is primarily composed of p-hydroxyphenyl structural units, while WS and PS lignins are mainly made up of guaiacyl units. Both the mass and energy yields of non-condensable gases from PKS pyrolysis were lower than those obtained from WS and PS pyrolysis at 650–850 °C, owing to the lower volatile content (75.21%) and lack of methoxy groups in PKS. Compared with WS and PS, higher bio-oil productivity was observed during PKS pyrolysis. Phenols were the main component of PKS bio-oil from pyrolysis at 500 °C, and the phenol content of PKS bio-oil (13.49%) was higher than in WS bio-oil (1.62%) and PS bio-oil (0.55%). A higher yield of biochar (on an ash-free basis) was also obtained from PKS pyrolysis. Because of its greater relative degree of ordered carbon, PKS biochar exhibited lower in situ reactivity during CO_2 or H_2O gasification than WS and PS biochars. A longer residence time and addition of steam were found to be beneficial during PKS biochar gasification.

  16. Approximations to the Non-Isothermal Distributed Activation Energy Model for Biomass Pyrolysis Using the Rayleigh Distribution

    Directory of Open Access Journals (Sweden)

    Dhaundiyal Alok

    2017-09-01

    Full Text Available This paper deals with the influence of some parameters relevant to biomass pyrolysis on the numerical solutions of the nonisothermal nth order distributed activation energy model using the Rayleigh distribution. Investigated parameters are the integral upper limit, the frequency factor, the heating rate, the reaction order and the scale parameters of the Rayleigh distribution. The influence of these parameters has been considered for the determination of the kinetic parameters of the non-isothermal nth order Rayleigh distribution from the experimentally derived thermoanalytical data of biomass pyrolysis.

  17. Doping droops.

    Science.gov (United States)

    Chaturvedi, Aditi; Chaturvedi, Harish; Kalra, Juhi; Kalra, Sudhanshu

    2007-01-01

    Drug abuse is a major concern in the athletic world. The misconception among athletes and their coaches is that when an athlete breaks a record it is due to some "magic ingredient" and not because of training, hard work, mental attitude and championship performance. The personal motivation to win in competitive sports has been intensified by national, political, professional and economic incentives. Under this increased pressure athletes have turned to finding this "magic ingredient". Athlete turns to mechanical (exercise, massage), nutritional (vitamins, minerals), pharmacological (medicines) or gene therapies to have an edge over other players. The World Anti-Doping Agency (WADA) has already asked scientists to help find ways to prevent gene therapy from becoming the newest form of doping. The safety of the life of athletes is compromised with all forms of doping techniques, be it a side effect of a drug or a new technique of gene doping.

  18. Thermal behaviour during the pyrolysis of low rank perhydrous coals

    Energy Technology Data Exchange (ETDEWEB)

    Arenillas, A.; Rubiera, F.; Pis, J.J.; Cuesta, M.J.; Suarez-Ruiz, I. [Instituto Nacional del Carbon, CSIC, Apartado 73, 33080 Oviedo (Spain); Iglesias, M.J. [Area de Quimica Organica, Universidad de Almeria, Carretera de Sacramento, 04120 Almeria (Spain); Jimenez, A. [Area de Cristalografia y Mineralogia, Departamento de Geologia, Campus de Llamaquique, 33005 Oviedo (Spain)

    2003-08-01

    Perhydrous coals are characterised by high H/C atomic ratios and so their chemical structure is substantially modified with respect to that of conventional coals. As a result, perhydrous coals show different physico-chemical properties to common coals (i.e. higher volatile matter content, enhancement of oil/tar potential, relatively lower porosity and higher fluidity during carbonisation). However, there is little information about thermal behaviour during the pyrolysis of this type of coal. In this work, six perhydrous coals (H/C ratio between 0.83 and 1.07) were pyrolysed and analysed by simultaneous thermogravimetry/mass spectrometry. The results of this work have revealed the influence of high H/C values on the thermal behaviour of the coals studied. During pyrolysis the perhydrous coals exhibit very well defined, symmetrical peaks in the mass loss rate profiles, while normal coals usually show a broader peak. The shape of such curves suggests that in perhydrous coals fragmentation processes prevailed over condensation reactions. The high hydrogen content of perhydrous coals may stabilise the free radicals formed during heat treatment, increasing the production of light components.

  19. Dependence of Pyrolysis Rate of Coal on Temperature

    Directory of Open Access Journals (Sweden)

    Slyusarskiy Konstantin V.

    2015-01-01

    Full Text Available Pyrolysis process of coal has been researched to define kinetic constants which can be used for design and optimization of different processes of fuel transformation. The article considers anthracite powders and bituminous coal of Krasnogorsky mine with the use of non-isothermal thermogravimetric analysis with mass spectrometry. Spectroscanning microscopy and laser diffraction for definition of sizes and forms of particles distribution has been done. Other parameters – carbon content, ash and volatiles, density and moisture have been defined by standard methods. Energy of activation and pre-exponent with the use of models of Freedman, Starink and distributed activation energy model (DAEM, and also relative deviation of design data from experimental ones have been designed. The results of the analysis have shown the important influence of volatiles content and coal transformation degree on maximum reaction rate. Energy activation values received with the help of DAEM model are higher than with Freedman and Starink models. Process of pyrolysis of bituminous coal has a big rate in comparison with anthracite, and is better described by the above-mentioned models.

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

    Energy Technology Data Exchange (ETDEWEB)

    Antonakou, E.V. [Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Kalogiannis, K.G.; Stephanidis, S.D. [Chemical Process Engineering Research Institute, 57001 Thermi, Thessaloniki (Greece); Triantafyllidis, K.S. [Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Chemical Process Engineering Research Institute, 57001 Thermi, Thessaloniki (Greece); Lappas, A.A. [Chemical Process Engineering Research Institute, 57001 Thermi, Thessaloniki (Greece); Achilias, D.S., E-mail: axilias@chem.auth.gr [Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)

    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.

  1. Pyrolysis of Rubber in a Screw Reactor

    Science.gov (United States)

    Lozhechnik, A. V.; Savchin, V. V.

    2016-11-01

    On the basis of an analysis of thermal methods described in the literature and from the results of experimental investigations of steam conversion, the authors have developed and created a facility for thermal processing of rubber waste. Rubber crumb was used as the raw material; the temperature in the reactor was 500°C; nitrogen, steam, and a mixture of light hydrocarbons (noncondensable part of pyrolysis products) represented the working medium. The pyrolysis yielded 36-38% of a solid fraction, 54-56% of a liquid hydrocarbon fraction, and 6-9% of noncondensable gases. Changes in the composition of the gas mixture have been determined at different stages of processing. Gas chromatography of pyrolysis gases has shown that the basic gases produced by pyrolysis are H2 and hydrocarbons C2H4, C3H6, C3H8, C4H8, C2H6, C3H6O2, and C4H10, and a small amount of H2S, CO, and CO2. Noncondensable gases will be used as a fuel to heat the reactor and to implement the process.

  2. Catalytic pyrolysis using UZM-44 aluminosilicate zeolite

    Science.gov (United States)

    Nicholas, Christopher P; Boldingh, Edwin P

    2013-12-17

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

  3. Characterization of Hydrotreated Fast Pyrolysis Liquids

    NARCIS (Netherlands)

    Oasmaa, A.; Kuoppala, E.; Ardiyanti, A.; Venderbosch, R. H.; Heeres, H. J.

    This paper focuses on analytical methods to determine the composition of hydrotreated fast pyrolysis liquids. With this information, it is possible to gain insights in the chemical transformations taking place during catalytic hydrotreatment (hydrogenation and/or hydrodeoxygenation, H DO) of

  4. Spray pyrolysis process for preparing superconductive films

    International Nuclear Information System (INIS)

    Hsu, H.M.; Yee, I.Y.

    1991-01-01

    This paper describes a spray pyrolysis method for preparing thin superconductive film. It comprises: preparing a spray pyrolysis solution comprising Bi,Sr,Ca and Cu metals in a solvent; heating a substrate to a first temperature; spraying the solution onto the heated substrate to form a film thereon; heating the film and substrate to a second temperature of about 700 degrees-825 degrees C, the second temperature being higher than the first temperature; heating the film and substrate to a third temperature of about 870 degrees-890 degrees C to melt the film; once the film and substrate reach the third temperature, further heat treating the film and substrate; cooling the film and substrate to ambient temperature. This patent also describes a spray pyrolysis method for preparing thin superconductive films. It comprises: preparing a spray pyrolysis solution comprising Bi, Ca and Cu metals and fluxing agent in a solvent; heating a substrate to a first temperature; spraying the solution onto the heated substrate to form a film thereon; heating the film and substrate to a second temperature about 700 degrees-825 degrees C, the second temperature being higher than the first temperature; heating the film and substrate at a third temperature about 840 degrees-860 degrees C; and cooling the film and substrate to ambient temperature

  5. In Situ Flash Pyrolysis of Straw

    DEFF Research Database (Denmark)

    Bech, Niels

    In-Situ Flash Pyrolysis of Straw Ph.D. dissertation by Niels Bech Submitted: April 2007. Supervisors: Professor Kim Dam-Johansen, Associate Professor Peter Arendt Jensen Erfaringerne med forbrænding af halm opnået gennem et årti har vist, at en proces der kan koncentrere energien på marken, fjerne...

  6. Flash pyrolysis kinetics of pine wood

    NARCIS (Netherlands)

    Wagenaar, B.M.; Prins, W.; van Swaaij, Willibrordus Petrus Maria

    1993-01-01

    The kinetics of sawdust pyrolysis in the temperature range from 300 to 600 °C has been measured. A thermogravimetric analyser was applied for the temperature range from 300 to 450 °C while for measurements in the temperature range from 450 to 600 °C, an entrained flow reactor has been used. The

  7. Thermal pyrolysis characteristics of macroalgae Cladophora glomerata.

    Science.gov (United States)

    Gao, Wenhua; Chen, Kefu; Zeng, Jinsong; Xu, Jun; Wang, Bin

    2017-11-01

    The Cladophora glomerata (C. glomerata) is a kind of widely distributed macroalgae in the freshwater ecosystems. It primarily consists of carbohydrates that can be converted into biofuel by pyrolysis. In this study, thermogravimetric analysis (TGA) was used to investigate the thermal behavior and kinetics of C. glomerata during the pyrolysis process. The results showed that heating rates slightly affect the decomposition properties of C. glomerata; with the heating rates increasing, the maximum peak of weight loss rate shifted to higher temperatures. The activation energies of C. glomerata pyrolysis reaction were 244.25 and 238.07kJ/mol, respectively, as calculated by Friedman and Kissinger-Akahira-Sunose (KAS) methods. The pre-exponential factor and reaction order were determined by Coats-Redfern model, and applied to simulate the pyrolysis process of C. glomerata. The model calculated data and experimental data were consistent. This study could provide theoretical supports for designing C. glomerata conversion processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Catalytic and noncatalytic gasification of pyrolysis oil

    NARCIS (Netherlands)

    van Rossum, G.; Kersten, Sascha R.A.; van Swaaij, Willibrordus Petrus Maria

    2007-01-01

    Gasification of pyrolysis oil was studied in a fluidized bed over a wide temperature range (523−914 °C) with and without the use of nickel-based catalysts. Noncatalytically, a typical fuel gas was produced. Both a special designed fluid bed catalyst and a crushed commercial fixed bed catalyst showed

  9. Effect of thickness on structural and electrical properties of Al-doped ZnO films

    Energy Technology Data Exchange (ETDEWEB)

    Garcés, F.A., E-mail: felipe.garces@santafe-conicet.gov.ar [Instituto de Física del Litoral (CONICET-UNL), Güemes 3450, Santa Fe S3000GLN (Argentina); Budini, N. [Instituto de Física del Litoral (CONICET-UNL), Güemes 3450, Santa Fe S3000GLN (Argentina); Arce, R.D.; Schmidt, J.A. [Instituto de Física del Litoral (CONICET-UNL), Güemes 3450, Santa Fe S3000GLN (Argentina); Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santiago del Estero 2829, Santa Fe S3000AOM (Argentina)

    2015-01-01

    In this work, we have investigated the influence of thickness on structural and electrical properties of Al-doped ZnO films. Transparent conducting oxide films were grown by the spray pyrolysis technique from precursors prepared via the sol–gel method. We determined the structural properties of the films by performing X-ray diffraction and mosaicity measurements, which evidenced an increase of disorder and inhomogeneity between crystalline domains as the films thickened. This behavior was contrasted with results obtained from electrical measurements and was attributed to plastic deformation of the films as their thickness increased. As a result, the carrier mobility, the optical gap and the activation energy are affected due to emerging grain boundaries and a higher degree of disorder. - Highlights: • Al-doped ZnO thin films on glass with different thicknesses • Film thickness affects the morphological and electrical properties. • Increasing time deposition allows modification of resistivity and Hall mobility. • Mosaicity between crystalline domains increases with film thickness.

  10. Effect of thickness on structural and electrical properties of Al-doped ZnO films

    International Nuclear Information System (INIS)

    Garcés, F.A.; Budini, N.; Arce, R.D.; Schmidt, J.A.

    2015-01-01

    In this work, we have investigated the influence of thickness on structural and electrical properties of Al-doped ZnO films. Transparent conducting oxide films were grown by the spray pyrolysis technique from precursors prepared via the sol–gel method. We determined the structural properties of the films by performing X-ray diffraction and mosaicity measurements, which evidenced an increase of disorder and inhomogeneity between crystalline domains as the films thickened. This behavior was contrasted with results obtained from electrical measurements and was attributed to plastic deformation of the films as their thickness increased. As a result, the carrier mobility, the optical gap and the activation energy are affected due to emerging grain boundaries and a higher degree of disorder. - Highlights: • Al-doped ZnO thin films on glass with different thicknesses • Film thickness affects the morphological and electrical properties. • Increasing time deposition allows modification of resistivity and Hall mobility. • Mosaicity between crystalline domains increases with film thickness

  11. Lignocellulose-derived porous phosphorus-doped carbon as advanced electrode for supercapacitors

    Science.gov (United States)

    Yi, Jianan; Qing, Yan; Wu, ChuTian; Zeng, Yinxiang; Wu, Yiqiang; Lu, Xihong; Tong, Yexiang

    2017-05-01

    Engineering porous heteroatom-doped carbon nanomaterials with remarkable capacitive performance is highly attractive. Herein, a simple and smart method has been developed to synthesize phosphorus (P) doped carbon with hierarchical porous structure derived from lignocellulose. Hierarchically porous P doped carbon is readily obtained by the pyrolysis of lignocellulose immersed in ZnCl2/NaH2PO4 aqueous solution, and exhibits excellent capacitive properties. The as-obtained P doped porous carbon delivers a significant capacitance of 133 F g-1 (146 mF cm-2) at a high current density of 10 A g-1 with outstanding rate performance. Furthermore, the P doped carbon electrode yields a long-term cycling durability with more than 97.9% capacitance retention after 10000 cycles as well. A symmetric supercapacitor with a maximum energy density of 4.7 Wh kg-1 is also demonstrated based on these P doped carbon electrodes.

  12. Electrochemical Behavior of TiO2 Nanoparticle Doped WO3 Thin Films

    Directory of Open Access Journals (Sweden)

    Suvarna R. Bathe

    2014-01-01

    Full Text Available Nanoparticle TiO2 doped WO3 thin films by pulsed spray pyrolysis technique have been studied on fluorine tin doped (FTO and glass substrate. XRD shows amorphous nature for undoped and anatase phase of TiO2 having (101 plane for nanoparticle TiO2 doped WO3 thin film. SEM shows microfibrous reticulated porous network for WO3 with 600 nm fiber diameter and nanocrystalline having size 40 nm for TiO2 nanoparticle doped WO3 thin film. TiO2 nanoparticle doped WO3 thin film shows ~95% reversibility due to may be attributed to nanocrystalline nature of the film, which helpful for charge insertion and deinsertion process. The diffusion coefficient for TiO2 nanoparticle doped WO3 film is less than undoped WO3.

  13. Pyrolysis of fibre residues with plastic contamination from a paper recycling mill: Energy recoveries

    International Nuclear Information System (INIS)

    Brown, Logan Jeremy; Collard, François-Xavier; Görgens, Johann

    2017-01-01

    Highlights: • Pyrolysis of fibre-plastics residues from paper recycling mill into fuel products. • Product with remarkable energy content up to 42.8 MJ/kg. • Influence of temperature on the product yields and fuel properties. • Effect of plastic composition on product properties. - Abstract: Pyrolysis is a promising technology for the production of marketable energy products from waste mixtures, as it decomposes heterogeneous material into homogenous fuel products. This research assessed the ability of slow pyrolysis to convert three waste streams, composed of fibre residues contaminated with different plastic mixtures, into char and tarry phase products at three different temperatures (300, 425 and 550 °C). The products were characterised in terms of mass yield, higher heating value (HHV) and gross energy conversion (EC). Significant amounts of hydrocarbon plastics in the feed materials increased the calorific values of the char (up to 32.9 MJ/kg) and tarry phase (up to 42.8 MJ/kg) products, comparable to high volatile bituminous A coal and diesel respectively. For all three waste streams converted at 300 °C, the majority of the energy in the feedstock was recovered in the char product (>80%), while deoxygenation of fibre component resulted in char with increased calorific value (up to 31.6 MJ/kg) being produced. Pyrolysis at 425 °C for two of the waste streams containing significant amounts of plastic produced both a valuable char and tarry phase, which resulted in an EC greater than 74%. Full conversion of plastic at 550 °C increased the tarry phase yield but dramatically decreased the char HHV. The influence of temperature on product yield and HHV was discussed based on the pyrolysis mechanisms and in relation to the plastic composition of the waste streams.

  14. A review on thermal and catalytic pyrolysis of plastic solid waste (PSW).

    Science.gov (United States)

    Al-Salem, S M; Antelava, A; Constantinou, A; Manos, G; Dutta, A

    2017-07-15

    Plastic plays an important role in our daily lives due to its versatility, light weight and low production cost. Plastics became essential in many sectors such as construction, medical, engineering applications, automotive, aerospace, etc. In addition, economic growth and development also increased our demand and dependency on plastics which leads to its accumulation in landfills imposing risk on human health, animals and cause environmental pollution problems such as ground water contamination, sanitary related issues, etc. Hence, a sustainable and an efficient plastic waste treatment is essential to avoid such issues. Pyrolysis is a thermo-chemical plastic waste treatment technique which can solve such pollution problems, as well as, recover valuable energy and products such as oil and gas. Pyrolysis of plastic solid waste (PSW) has gained importance due to having better advantages towards environmental pollution and reduction of carbon footprint of plastic products by minimizing the emissions of carbon monoxide and carbon dioxide compared to combustion and gasification. This paper presents the existing techniques of pyrolysis, the parameters which affect the products yield and selectivity and identify major research gaps in this technology. The influence of different catalysts on the process as well as review and comparative assessment of pyrolysis with other thermal and catalytic plastic treatment methods, is also presented. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Acoustic and Petrophysical Evolution of Organic-Rich Chalk Following Maturation Induced by Unconfined Pyrolysis

    Science.gov (United States)

    Shitrit, Omri; Hatzor, Yossef H.; Feinstein, Shimon; Vinegar, Harold J.

    2017-12-01

    Thermal maturation is known to influence the rock physics of organic-rich rocks. While most studies were performed on low-porosity organic-rich shales, here we examine the effect of thermal maturation on a high-porosity organic-rich chalk. We compare the physical properties of native state immature rock with the properties at two pyrolysis-simulated maturity levels: early-mature and over-mature. We further evaluate the applicability of results from unconfined pyrolysis experiments to naturally matured rock properties. Special attention is dedicated to the elastic properties of the organic phase and the influence of bitumen and kerogen contents. Rock physics is studied based on confined petrophysical measurements of porosity, density and permeability, and measurements of bedding-normal acoustic velocities at estimated field stresses. Geochemical parameters like total organic carbon (TOC), bitumen content and thermal maturation indicators are used to monitor variations in density and volume fraction of each phase. We find that porosity increases significantly upon pyrolysis and that P wave velocity decreases in accordance. Solids density versus TOC relationships indicate that the kerogen increases its density from 1.43 to 1.49 g/cc at the immature and early-mature stages to 2.98 g/cc at the over-mature stage. This density value is unusually high, although increase in S wave velocity and backscatter SEM images of the over-mature samples verify that the over-mature kerogen is significantly denser and stiffer. Using the petrophysical and acoustic properties, the elastic moduli of the rock are estimated by two Hashin-Shtrikman (HS)-based models: "HS + BAM" and "HS kerogen." The "HS + BAM" model is calibrated to the post-pyrolysis measurements to describe the mechanical effect of the unconfined pyrolysis on the rock. The absence of compaction in the pyrolysis process causes the post-pyrolysis samples to be extremely porous. The "HS kerogen" model, which simulates a

  16. Influence of alumina on photoluminescence and thermoluminescence characteristics of Gd{sup 3+} doped barium borophosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Kalpana, T. [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522 510, A.P. (India); Gandhi, Y. [Department of Physics, Kakani Venkata Ratnam College, Nandigama 521 185, A.P. (India); Sanyal, Bhaskar [Food Technology Division, Bhabha Atomic Research Center, Trombay, Mumbai 400 085 (India); Sudarsan, V. [Bhabha Atomic Research Centre, Chemistry Division, Mumbai 400 085 (India); Bragiel, P.; Piasecki, M. [Institute of Physics, Jan Dlugosz University, Ul. Armii Krajowej 13/15, Czestochowa 42-201 (Poland); Kumar, V. Ravi [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522 510, A.P. (India); Veeraiah, N., E-mail: nvr8@rediffmail.com [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522 510, A.P. (India)

    2016-11-15

    Gd{sup 3+} doped barium borophosphate glasses mixed with varying concentration of Al{sub 2}O{sub 3} are synthesized. Photoluminescence, thermoluminescence and other spectroscopic studies viz., IR and EPR spectral studies, have been carried out. IR spectral studies of these glasses indicated that there is a gradual increase in the degree of depolymerization of the glass network with increase in the concentration of Al{sub 2}O{sub 3} upto 3.0 mol%. The EPR spectral studies revealed the lowest concentration of Gd{sup 3+} ion clusters in the glass mixed with 3.0 mol% of Al{sub 2}O{sub 3}. The photoluminescence emission spectra exhibited strong ultraviolet blue emission at 311 under excitation at 273 nm due to {sup 6}P{sub 7/2}→{sup 8}S{sub 7/2} transition of Gd{sup 3+} ions. The intensity of this band is found to be enhanced four times when the glass mixed with 3.0 mol% of Al{sub 2}O{sub 3} with respect to that of alumina free glass. The enrichment of this emission is attributed to the declustering of Gd{sup 3+} ions by Al{sup 3+} ions. Thermoluminescence (TL) characteristics of these glasses have also been investigated after irradiating them with different doses of γ-rays (in the range 0–8.0 kGy). The TL emission exhibited a dosimetric peak at about 200 °C. The TL output under this glow peak is observed to increase with increase of γ-ray dose. For any fixed γ-ray dose, the TL output is increased with increasing Al{sub 2}O{sub 3} content up to 3.0 mol% and beyond this concentration quenching of TL is observed. The mechanisms responsible for TL emission and the variation in TL output with the concentration of Al{sub 2}O{sub 3} are quantitatively discussed in terms of electron and hole centers developed due to interaction of γ-rays with the glass network. The dose response of these glass samples exhibited linear behavior in the dose range 0–8.0 kGy.

  17. Influence of the cooling rate on the main factors affecting current-carrying ability in pure and SiC-doped MgB2 superconductors

    International Nuclear Information System (INIS)

    Shcherbakova, O V; Pan, A V; Soltanian, S; Dou, S X; Wexler, D

    2007-01-01

    We have systematically studied and compared the effect of cooling rate on microstructure, critical current density, upper critical field and irreversibility field in pure and 10 wt% SiC-added MgB 2 superconductors. The sintering process was carried out on the samples at a temperature of 750 deg. C for 1 h followed by quenching or cooling to room temperature in 0.3 h (2433 deg. C h -1 ), 14 h (52 deg. C h -1 ) and 25 h (30 deg. C h -1 ). Changes in the microstructure due to variations in cooling rate have been studied with the help of scanning and transmission electron microscopy. Correlations between microstructure and superconducting properties have been observed, identified and explained for both pure and SiC-added MgB 2 samples. Modifications to the pinning environment and grain boundary transparency are considered to be responsible for variations in the current-carrying ability. The dominant pinning on grain boundaries in the pure MgB 2 samples and on nano-inclusions (inducing accompanying defects) in the SiC-doped samples is clearly distinguished. On the basis of our experimental results, we have concluded that the cooling rate can be an important parameter influencing the superconducting properties of MgB 2 samples

  18. Influence of structural disorder on low-temperature behavior of penetration depth in electron-doped high-TC thin films

    International Nuclear Information System (INIS)

    Lanfredi, A.J.C.; Sergeenkov, S.; Araujo-Moreira, F.M.

    2006-01-01

    To probe the influence of structural disorder on low-temperature behavior of magnetic penetration depth, λ(T), in electron-doped high-T C superconductors, a comparative study of high-quality Pr 1.85 Ce 0.15 CuO 4 (PCCO) and Sm 1.85 Ce 0.15 CuO 4 (SCCO) thin films is presented. The λ(T) profiles are extracted from conductance-voltage data using a highly-sensitive home-made mutual-inductance technique. The obtained results confirm a d-wave pairing mechanism in both samples (with nodal gap parameter Δ 0 /k B T C =2.0 and 2.1 for PCCO and SCCO films, respectively), substantially modified by impurity scattering (which is more noticeable in less homogeneous SCCO films) at the lowest temperatures. More precisely, Δλ(T)=λ(T)-λ(0) is found to follow the Goldenfeld-Hirschfeld interpolation formulae Δλ(T)/λ(0)=AT 2 /(T+T 0 ) with T 0 =ln(2)k B Γ 1/2 Δ 0 1/2 being the crossover temperature which demarcates pure and impure scattering processes (T 0 /T C =0.13 and 0.26 for PCCO and SCCO films, respectively). The value of the extracted impurity scattering rate Γ correlates with the quality of our samples and is found to be much higher in less homogeneous films with lower T C

  19. The influence of exercise and dehydration on the urine concentrations of salbutamol after inhaled administration of 1600 µg salbutamol as a single dose in relation to doping analysis

    DEFF Research Database (Denmark)

    Haase, Christoffer Bjerre; Backer, Vibeke; Kalsen, Anders

    2016-01-01

    The present study investigated the influence of exercise and dehydration on the urine concentrations of salbutamol after inhalation of that maximal permitted (1600 µg) on the 2015 World Anti-Doping Agency (WADA) prohibited list. Thirteen healthy males participated in the study. Urine concentrations...... of salbutamol were measured during three conditions: exercise (EX), exercise+dehydration (EXD), and rest (R). Exercise consisted of 75 min cycling at 60% of VO2max and a 20-km time-trial. Fluid intake was 2300, 270, and 1100 mL during EX, EXD, and R, respectively. Urine samples of salbutamol were collected 0.......0±0.7 ng/mL) than EX(3.8±0.8 ng/mL) and EXD(3.6±0.8 ng/mL). AUC was lower for R (14.1±2.8 ng/mL·∙h) than EX (16.9±2.9 ng/mL·∙h)(Pdehydration affect urine concentrations of salbutamol and increase the risk of Adverse Analytical Findings...

  20. Influence of Eu{sup 3+} doping content on antioxidant properties of Lu{sub 2}O{sub 3} sol-gel derived nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Olvera Salazar, Arturo [Universidad Del Valle de México Campus Lomas Verde, Paseo de las Aves No.1 Col. San Mateo Nopala. Naucalpan de Juárez, Edo. Méx. C.P. 53220 (Mexico); García Hernández, Margarita, E-mail: margarita.garcia@itcm.edu.mx [Tecnológico Nacional de México-Instituto Tecnológico de Ciudad Madero. Av. 1o. de Mayo esq. Sor Juana Inés de la Cruz s/n Col. Los Mangos Cd. Madero Tamaulipas C.P.89440 (Mexico); López Camacho, Perla Yolanda [Universidad Autónoma Metropolitana, Unidad Cuajimalpa. Av. Vasco de Quiroga 4871, Col. Santa Fé Cuajimalpa, Cuajimalpa D.F. C.P. 05348 (Mexico); López Marure, Arturo [Instituto Politécnico Nacional, CICATA Altamira. Carretera Tampico-Puerto Industrial Altamira, Altamira, Tamaulipas C.P. 89600 (Mexico); Reyes de la Torre, Adriana Isabel [Tecnológico Nacional de México-Instituto Tecnológico de Ciudad Madero. Av. 1o. de Mayo esq. Sor Juana Inés de la Cruz s/n Col. Los Mangos Cd. Madero Tamaulipas C.P.89440 (Mexico); Morales Ramírez, Ángel de Jesús [Instituto Politécnico Nacional, CIITEC Azcapotzalco. Cerrada de Cecati S/N, Col. Santa Catarina, Azcapotzalco, D.F. C.P. 02250 (Mexico); and others

    2016-12-01

    This paper presents the synthesis of pure and europium-doped lutetium oxide (Lu{sub 2}O{sub 3}) powders prepared by sol-gel method. The influence of europium ion concentration into Lu{sub 2}O{sub 3} nanocrystallites was investigated for first time in an in vitro system using a modified ABTS radical cation decolorization assay to determine the antioxidant activity. The crystalline structure of Lu{sub 2}O{sub 3} and Eu:Lu{sub 2}O{sub 3} powders was elucidated by XRD obtaining cubic phase in all system without secondary products in accordance with FT-IR results. By TEM and Scherrer equation, it was determined that Lu{sub 2}O{sub 3} and Eu:Lu{sub 2}O{sub 3} powders presented nearly spherical particle morphology with crystallites sizes in the range of 8 to 13 nm. The antioxidant assays results revealed that europium ion enhance Lu{sub 2}O{sub 3} powders antioxidant properties, showing that 12.5 mol% of europium is sufficient to reach its maximum capacity. - Highlights: • For first time the effect of the Eu content vs antioxidant properties was studied. • Sol-gel particles of Lu{sub 2}O{sub 3}:Eu{sup 3+} nanopowders showed relevant antioxidant properties. • The antioxidant behavior remains stable at higher Eu levels.

  1. Influence of Ta and Ti Doping on the High Field Performance of (Nb, Ta, Ti)3Sn Multifilamentary Wires based on Osprey Bronze with High Tin Content

    International Nuclear Information System (INIS)

    Abaecherli, V; Uglietti, D; Lezza, P; Seeber, B; Fluekiger, R; Cantoni, M; Buffat, P-A

    2006-01-01

    Ta and Ti are the most widely used additions for technical Nb 3 Sn multifilamentary superconductors. These elements are known to influence grain growth, grain morphology and chemical composition in the A15 layer, hence the current carrying properties of the wires over a wide magnetic field range. So far only few studies tried to compare systematically Ta and Ti doped and undoped Nb 3 Sn wires in the frame of the same work, down to a nanometric scale. We present an investigation on several multifilamentary (Nb, Ta, Ti) 3 Sn bronze route wires, fabricated at a laboratory scale, with various amounts of additives. The wires consist of fine filaments embedded in a Cu-Sn or Cu-Sn-Ti Osprey bronze with > 15 wt.% Sn and an external Cu stabilization. Microstructural observations are compared with the results of J c and n values measured up to 21 T at 4.2 and 2.2 K, and for longitudinal strains up to 0.5%. Non-Cu J c values up to 300 Amm -2 and n values up to 50 at 17 T and 4.2 K show clearly that wires with Ti addition to the bronze have a better performance with respect to wires with Ti additions to the filaments

  2. Study of the influence of the codopant over the photoluminescent properties of PAA doped with Eu3+, Gd3+, and Tb3+

    International Nuclear Information System (INIS)

    Flores, M.; Arroyo, R.

    2003-01-01

    The results are presented obtained about the synthesis of acrylic poly acid characterization (PAA) doped with Eu 3+ , Gd 3+ and Tb 3+ . They got ready materials with even of these ions and it was studied the influence of the co dopant in the processes of emission of Eu 3+ (λ em = 618 nm), Gd 3+ (λ em = 624 nm) and Tb 3+ (λ em = 546 nm), as well as their effect in the phosphorescence (λ em = 450 nm) of the polymeric matrix. It was found that the intensity of the emission of Eu 3+ diminishes substantially due to the presence of the ions Gd 3+ , contrary to what happens when the co dopant is Tb 3+ , which causes an increase. In the one case of the emission of Tb 3+ , this it increases with the presence of Gd 3+ but it diminishes when Eu 3+ is present. These results are consequence of the homogeneous distribution of those dopants and of the phenomena of energy transfer that happen in the materials synthesized. (Author)

  3. Influences of metallic doping on anatase crystalline titanium dioxide: From electronic structure aspects to efficiency of TiO2-based dye sensitized solar cell (DSSC)

    International Nuclear Information System (INIS)

    Nguyen, Thuy Trang; Tran, Van Nam; Bach, Thanh Cong

    2014-01-01

    In this work, we examined the influences of metallic X dopants (X = Be, Mg, Ca, Zn, Al, W and Nb) on the electronic structure of anatase TiO 2 in the framework of density functional theory (DFT). The dopant-induced electronic structure modifications are believed to directly change the photovoltaic (PV) behaviors of the X-doped TiO 2 based DSSCs. The dopants are shown to either directly inhibit the intrinsic Ti 3+ and oxygen vacancy surface defects of TiO 2 or enhance these defects depending on their valence states. These dopant-induced defect modifications, in turn, strongly affect the PV behaviors of the DSSCs. The combined effect of electronic structure and surface-defect modifications determined the photoelectric efficiency of the device. - Highlights: • Ca, Al and W dopants strongly distort the lattice and narrowed the band gap. • Nb negatively shifts while the others positive shift the conduction band bottom. • Nb and W dopants reduce Ti 4+ to Ti 3+ without forming oxygen vacancy. • Be, Mg, Ca, Zn and Al dopants induce oxygen vacancy without Ti 3+ . • Nb and W inhibit the surface defects while the others do the reversed manner

  4. Improved performance of low cost CuInS2 superstrate-type solar cells using Zinc assisted spray pyrolysis processing

    Science.gov (United States)

    Cheshme Khavar, Amir Hossein; Mahjoub, Ali Reza; Taghavinia, Nima

    2017-12-01

    Superstrate configuration CuInS2 (CIS) solar cells are fabricated using a spray pyrolysis method. We avoided selenization process, cyanide etching and CdS buffer layer, to keep the process ‘green’. CIS layers are formed by spray pyrolysis of an aqueous precursor ink containing metal chloride salts and thiourea at 350 °C. We investigated the effect of intentional Zn doping on structural, morphological and photovoltaic response of the fabricated CIS films by dissolving ZnCl2 in aqueous precursor solution. At a zinc doping level ranging between 0.25 and 1.00 mol%, Zn doping is found to improve the CIS crystal growth and surface morphology of CIS films. Compared with the performance of the non-doped CIS cell, the Zn-doped CIS solar cell displayed a remarkable efficiency enhancement of 58-97% and the maximum enhancement was obtained at a Zn content of 0.5 mol%. The device structure consists of    and show promising PCE of 4.29 % without any anti-reflection coating. Over the course of 300 d under ambient condition, the fabricated device showed only 1% loss in efficiency.

  5. Co-pyrolysis of waste tire/coal mixtures for smokeless fuel, maltenes and hydrogen-rich gas production

    International Nuclear Information System (INIS)

    Bičáková, Olga; Straka, Pavel

    2016-01-01

    Highlights: • Co-pyrolysis of waste tires/coal mixtures yields mainly smokeless fuel (55–74 wt%). • Alternatively, the smokeless fuel can serve as carbonaceous sorbent. • The obtained tar contained maltenes (80–85 wt%) and asphaltenes (6–8 wt%). • Tar from co-pyrolysis can serve as heating oil or a source of maltenes for repairing of asphalt surfaces. • The hydrogen-rich gas was obtained (61–65 vol% H_2, 24–25 vol% CH_4, 1.4–2 vol% CO_2). - Abstract: The processing of waste tires with two different types of bituminous coal was studied through the slow co-pyrolysis of 1 kg of waste tire/coal mixtures with 15, 30 and 60 wt% waste tires on a laboratory scale. The waste tire/coal mixtures were pyrolysed using a quartz reactor in a stationary bed. The mixtures were heated at a rate 5 °C/min up to the final temperature of 900 °C with a soaking time of 30 min at the required temperature. The mass balance of the process and the properties of the coke and tar obtained were evaluated, further, the influence of the admixture in the charge on the amount and composition of the obtained coke and tar was determined. It was found that the smokeless fuel/carbonaceous sorbent and a high yield of tar for further use can be obtained through the slow co-pyrolysis. The obtained tars contained mostly maltenes (80–85 wt%). FTIR analysis showed that the maltenes from the co-pyrolysis of coal/waste tires exhibited significantly lower aromaticity as compared with that from coal alone. The gas obtained from pyrolysis or co-pyrolysis of waste tire/coal mixtures contained a high amount of hydrogen (above 60 vol%) and methane (above 20 vol%).

  6. Influence of Zr and Ce doping on electromagnetic properties of (Gd,Y)-Ba-Cu-O superconducting tapes fabricated by metal organic chemical vapor deposition

    International Nuclear Information System (INIS)

    Selvamanickam, V.; Chen, Y.; Xie, J.; Zhang, Y.; Guevara, A.; Kesgin, I.; Majkic, G.; Martchevsky, M.

    2009-01-01

    (Gd,Y)Ba 2 Cu 3 O x tapes have been fabricated by metal organic chemical vapor deposition (MOCVD) with Zr-doping levels of 0-15 mol.% and Ce doping levels of 0-10 mol.% in 0.4 μm thick films. The critical current density (J c ) of Zr-doped samples at 77 K, 1 T applied in the orientation of H -parallel c is found to increase with Zr content and shows a maximum at 7.5% Zr doping. The 7.5% Zr-doped sample exhibits a critical current density (J c ) of 0.95 MA/cm 2 at H -parallel c which is more than 70% higher than the J c of the undoped sample. The peak in J c at H -parallel c is 83% of that at H -parallel a-b in the 7.5% Zr-doped sample which is more than twice as that in the undoped sample. Superconducting transition temperature (T c ) values as high as about 89 K have been achieved in samples even with 15% Zr and 10% Ce. Ce-doped samples with and without Ba compensation are found to exhibit substantially different J c values as well as angular dependence characteristics.

  7. Influence of Zr and Ce doping on electromagnetic properties of (Gd,Y)-Ba-Cu-O superconducting tapes fabricated by metal organic chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Selvamanickam, V., E-mail: selva@uh.ed [Department of Mechanical Engineering and Texas Center for Superconductivity, University of Houston, 4800 Calhoun Rd., Houston, TX 77204-4006 (United States); Chen, Y.; Xie, J. [SuperPower Inc., 450 Duane Ave., Schenectady, NY 12304 (United States); Zhang, Y.; Guevara, A.; Kesgin, I.; Majkic, G. [Department of Mechanical Engineering and Texas Center for Superconductivity, University of Houston, 4800 Calhoun Rd., Houston, TX 77204-4006 (United States); Martchevsky, M. [SuperPower Inc., 450 Duane Ave., Schenectady, NY 12304 (United States)

    2009-12-01

    (Gd,Y)Ba{sub 2}Cu{sub 3}O{sub x} tapes have been fabricated by metal organic chemical vapor deposition (MOCVD) with Zr-doping levels of 0-15 mol.% and Ce doping levels of 0-10 mol.% in 0.4 mum thick films. The critical current density (J{sub c}) of Zr-doped samples at 77 K, 1 T applied in the orientation of H -parallel c is found to increase with Zr content and shows a maximum at 7.5% Zr doping. The 7.5% Zr-doped sample exhibits a critical current density (J{sub c}) of 0.95 MA/cm{sup 2} at H -parallel c which is more than 70% higher than the J{sub c} of the undoped sample. The peak in J{sub c} at H -parallel c is 83% of that at H -parallel a-b in the 7.5% Zr-doped sample which is more than twice as that in the undoped sample. Superconducting transition temperature (T{sub c}) values as high as about 89 K have been achieved in samples even with 15% Zr and 10% Ce. Ce-doped samples with and without Ba compensation are found to exhibit substantially different J{sub c} values as well as angular dependence characteristics.

  8. The effect of bioleaching on sewage sludge pyrolysis.

    Science.gov (United States)

    Chen, Zhihua; Hu, Mian; Cui, Baihui; Liu, Shiming; Guo, Dabin; Xiao, Bo

    2016-02-01

    The effects of bioleaching on sewage sludge pyrolysis were studied. Sewage sludge was treated by bioleaching with solid concentrations of 6% (w/v), 8% (w/v), 10% (w/v). Results showed that bioleaching treatment could modify the physicochemical properties of sewage sludge and enhance the metals removal. The optimum removal efficiencies of heavy metals were achieved with solid concentration of 6% (w/v) bioleaching treatment: Cu, 73.08%; Zn, 78.67%; Pb, 24.65%; Cd, 79.46%. The characterization results of thermogravimetric analysis (TGA) showed that the bioleached sewage sludge with a 6% (w/v) solid concentration treatment was the easiest to decompose. Pyrolytic experiments of bioleached sewage sludge were performed in a laboratory-scale fixed bed reactor. Results indicated that bioleaching treatment greatly influenced the product yields and gas composition. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Structural and photoluminescence characterization of SnO{sub 2}: F thin films deposited by advanced spray pyrolysis technique at low substrate temperature

    Energy Technology Data Exchange (ETDEWEB)

    Shewale, P.S. [Thin Film Physics Laboratory, Department of Electronics, Shivaji University, Kolhapur 416004 (India); Ung Sim, Kyu; Kim, Ye-bin; Kim, J.H. [Department of Materials Science and Engineering, Chonnam National University, 300 Yongbong-Dong, Buk-Gu, Gwangju 500757 (Korea, Republic of); Moholkar, A.V. [Department of Physics, Shivaji University, Kolhapur 416004 (India); Uplane, M.D., E-mail: mdu_eln@unishivaji.ac.in [Thin Film Physics Laboratory, Department of Electronics, Shivaji University, Kolhapur 416004 (India)

    2013-07-15

    Fluorine doped tin oxide (FTO) thin films were deposited on glass substrates, at different substrate temperatures using advanced spray pyrolysis technique. X-ray diffraction studies showed that the crystallinity of the thin films increased with increasing substrate temperature. FESEM and AFM studies support the conclusions drawn from X-ray diffraction studies. X-ray photoelectron studies confirm oxygen deficiency in formation of the FTO nanocrystallites. The photoluminescence of the FTO films were investigated. It was found that, room temperature photoluminescence spectra are dominated by oxygen vacancies and exhibit a rich violet photoluminescence band about ∼404 nm with an extensively feeble red emission about 700 nm. The Photoluminescence intensity varies with the substrate temperature. The photoemission position is observed to be independent of substrate temperature. -- Highlights: ► Photoluminescent FTO thin films were deposited at low substrate temperatures. ► Influence of substrate temperature on the PL characteristics was studied. ► The samples are polycrystalline with a cassiterite tetragonal crystal structure. ► The room temperature UV/violet PL emission was dominated by the oxygen vacancies. ► PL efficiency is optimum at 613 K substrate temperature.

  10. Influence of dopant segregation on the work function and electrical properties of Ge-doped in comparison to Sn-doped In{sub 2}O{sub 3} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Hoyer, Karoline L.; Hubmann, Andreas H.; Klein, Andreas [Surface Science Division, Institute of Materials Science, Technische Universitaet Darmstadt (Germany)

    2017-02-15

    Ge-doped In{sub 2}O{sub 3} thin films prepared by magnetron sputtering are studied using photoelectron spectroscopy and Hall effect measurements. Carrier conductivities of up to 8.35 x 10{sup 3} S cm{sup -1} and carrier mobilities of up to 57 cm{sup 2} V{sup -1}s{sup -1} are observed. The surface Ge concentration is enhanced by a factor of 2-3 compared to the concentration in the interior of the films. The surface Ge concentration increases with more oxidizing deposition conditions, in opposite to what has been reported for Sn-doped In{sub 2}O{sub 3}. Ge-doped In{sub 2}O{sub 3} films exhibit higher work functions as compared to Sn-doped films, in particular at oxidizing conditions. This is attributed to the formation of a GeO{sub 2} surface phase. While segregation of Sn reduces the carrier mobility due to grain boundary scattering, Ge segregation does not show such an effect. The differences are attributed to the different oxidation states of the segregated dopants, in agreement with the observed dependence of segregation on oxygen activity. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. TG-FTIR analysis of biomass pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Bassilakis, R.; Carangelo, R.M.; Wojtowicz, M.A. [Advanced Fuel Research Inc., Hartford, CT (United States)

    2001-10-09

    A great need exists for comprehensive biomass-pyrolysis models that could predict yields and evolution patterns of selected volatile products as a function of feedstock characteristics and process conditions. A thermogravimetric analyzer coupled with Fourier transform infrared analysis of evolving products (TG-FTIR) can provide useful input to such models in the form of kinetic information obtained under low heating rate conditions. In this work, robust TG-FTIR quantification routes were developed for infrared analysis of volatile products relevant to biomass pyrolysis. The analysis was applied to wheat straw, three types of tobacco (Burley, Oriental, and Bright) and three biomass model compounds (xylan, chlorogenic acid, and D-glucose). Product yields were compared with literature data, and species potentially quantifiable by FT-IR are reviewed. Product-evolution patterns are reported for all seven biomass samples. 41 refs., 7 figs., 2 tabs.

  12. Methods and apparatuses for deoxygenating pyrolysis oil

    Science.gov (United States)

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

    2017-09-12

    Methods and apparatuses are provided for deoxygenating pyrolysis oil. A method includes contacting a pyrolysis oil with a deoxygenation catalyst in a first reactor at deoxygenation conditions to produce a first reactor effluent. The first reactor effluent has a first oxygen concentration and a first hydrogen concentration, based on hydrocarbons in the first reactor effluent, and the first reactor effluent includes an aromatic compound. The first reactor effluent is contacted with a dehydrogenation catalyst in a second reactor at conditions that deoxygenate the first reactor effluent while preserving the aromatic compound to produce a second reactor effluent. The second reactor effluent has a second oxygen concentration lower than the first oxygen concentration and a second hydrogen concentration that is equal to or lower than the first hydrogen concentration, where the second oxygen concentration and the second hydrogen concentration are based on the hydrocarbons in the second reactor effluent.

  13. Decarbonisation of fossil energy via methane pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Kreysa, G.; Agar, D.W.; Schultz, I. [Technische Univ. Dortmund (Germany)

    2010-12-30

    Despite the rising consumption of energy over the last few decades, the proven reserves of fossil fuels have steadily increased. Additionally, there are potentially tremendous reserves of methane hydrates available, which remain to be exploited. The use of fossil energy sources is thus increasingly being dictated less by supply than by the environmental concerns raised by climate change. In the context of the decarbonisation of the global energy system that this has stimulated, new means must be explored for using methane as energy source. Noncatalytic thermal pyrolysis of methane is proposed here as a promising concept for utilising methane with low to zero carbon dioxide emissions. Following cracking, only the energy content of the hydrogen is used, while the carbon can be stored safely and retrievably in disused coal mines. The thermodynamics and different process engineering concepts for the technical realisation of such a carbon moratorium technology are discussed. The possible contribution of methane pyrolysis to carbon negative geoengineering is also addressed. (orig.)

  14. Catalytic flash pyrolysis of oil-impregnated-wood and jatropha cake using sodium based catalysts

    KAUST Repository

    Imran, Ali; Bramer, Eddy A.; Seshan, Kulathuiyer; Brem, Gerrit

    2015-01-01

    Catalytic pyrolysis of wood with impregnated vegetable oil was investigated and compared with catalytic pyrolysis of jatropha cake making use of sodium based catalysts to produce a high quality bio-oil. The catalytic pyrolysis was carried out in two

  15. The influence of silver-ion doping using ion implantation on the luminescence properties of Er–Yb silicate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Stanek, S., E-mail: stanislav.stanek@vscht.cz [Department of Inorganic Chemistry, Faculty of Chemical Technology, University of Chemistry and Technology, Technicka 5, 16628 Prague (Czech Republic); Nekvindova, P.; Svecova, B.; Vytykacova, S.; Mika, M. [Department of Inorganic Chemistry, Faculty of Chemical Technology, University of Chemistry and Technology, Technicka 5, 16628 Prague (Czech Republic); Oswald, J. [Institute of Physics, Academy of Science of the Czech Republic, Cukrovarnicka 10/112, 162 00 Prague (Czech Republic); Mackova, A.; Malinsky, P. [Nuclear Physics Institute, Academy of Sciences of the Czech Republic, 25068 Rez (Czech Republic); Department of Physics, Faculty of Science, J.E. Purkinje University, Ceske mladeze 8, 40096 Usti nad Labem (Czech Republic); Spirkova, J. [Department of Inorganic Chemistry, Faculty of Chemical Technology, University of Chemistry and Technology, Technicka 5, 16628 Prague (Czech Republic)

    2016-03-15

    A set of zinc-silicate glasses with different ratios of erbium and ytterbium was fabricated. To achieve Ag-rich thin films in a sub-surface layer, ion-implantation technique at an energy of 1.2 MeV and 1.7 MeV with a fluence of 1 × 10{sup 16} cm{sup −2} was used. Post-implantation annealing was also applied. Changes in the spectroscopic and lasing properties of erbium ions as a function of implantation fluence of silver were studied with the aim to assess the positive effect of silver as a sensitiser of erbium luminescence. Therefore, absorption spectra in the visible range as well as luminescence spectra in the near-infrared range were measured and partially also the {sup 4}I{sub 11/2}–{sup 4}I{sub 15/2} transition of the erbium ion was studied. The results showed that silver positively influenced luminescence intensity at 1530 nm by increasing it almost three times. The biggest increase was achieved in glass with the highest concentration of erbium. Luminescence lifetime was not significantly influenced by the presence of silver and still remained around 10 ms.

  16. Pyrolysis Processing of Waste Peanuts Crisps

    Directory of Open Access Journals (Sweden)

    Grycová Barbora

    2015-12-01

    Full Text Available Wastes are the most frequent "by-product" of human society. The Czech Republic still has a considerable room for energy reduction and material intensiveness of production in connection with the application of scientific and technical expertise in the context of innovation cycles. Pyrolysis waste treatment is a promising alternative to the production of renewable hydrogen as a clean fuel. It can also reduce the environmental burden and the amount of waste in the environment at the same time.

  17. Reaction mechanisms in cellulose pyrolysis: a literature review

    Energy Technology Data Exchange (ETDEWEB)

    Molton, P.M.; Demmitt, T.F.

    1977-08-01

    A bibliographic review of 195 references is presented outlining the history of the research into the mechanisms of cellulose pyrolysis. Topics discussed are: initial product identification, mechanism of initial formation of levoglucosan, from cellulose and from related compounds, decomposition of cellulose to other compounds, formation of aromatics, pyrolysis of levoglucosan, crosslinking of cellulose, pyrolytic reactions of cellulose derivatives, and the effects of inorganic salts on the pyrolysis mechanism. (JSR)

  18. Experimental investigation of pyrolysis process of corn straw

    OpenAIRE

    Lei Wang; Shengqiang Shen; Shuhua Yang; Xinguang Shi

    2010-01-01

    The present paper was performed to analyze the pyrolysis process of corn straw. Based on the thermogravimetric analysis, the component of pyrolysis gas of corn straw was tested using the gas chromatograph analyzer. Experimental results showed that, as the reaction temperature increases, the component of H 2 and CH 4 increases, whereas the component of CO and CO 2 decreases. Finally, the mechanism of pyrolysis process of corn straw was revealed from the point of view of the molecular structure...

  19. Rapid quantification of biomarkers during kerogen microscale pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Stott, A.W.; Abbott, G.D. [Fossil Fuels and Environmental Geochemistry NRG, The University, Newcastle-upon-Tyne (United Kingdom)

    1995-02-01

    A rapid, reproducible method incorporating closed system microscale pyrolysis and thermal desorption-gas chromatography/mass spectrometry has been developed and applied to the quantification of sterane biomarkers released during pyrolysis of the Messel oil shale kerogen under confined conditions. This method allows a substantial experimental concentration-time data set to be collected at accurately controlled temperatures, due to the low thermal inertia of the microscale borosilicate glass reaction vessels, which facilitates kinetic studies of biomarker reactions during kerogen microscale pyrolysis

  20. Changes imposed by pyrolysis, thermal gasification and incineration on composition and phosphorus fertilizer quality of municipal sewage sludge

    DEFF Research Database (Denmark)

    Thomsen, Tobias Pape; Sárossy, Zsuzsa; Ahrenfeldt, Jesper

    2017-01-01

    Fertilizer quality of ash and char from incineration, gasification and pyrolysis of a single municipal sewage sludge sample were investigated by comparing composition and phosphorus (P) plant availability. A process for post oxidation of gasification ash and pyrolysis char was developed and the o......Fertilizer quality of ash and char from incineration, gasification and pyrolysis of a single municipal sewage sludge sample were investigated by comparing composition and phosphorus (P) plant availability. A process for post oxidation of gasification ash and pyrolysis char was developed...... and the oxidized materials were investigated as well. Sequential extraction with full elemental balances of the extracted pools as well as scanning electron microscopy with energy dispersive X-ray spectroscopy were used to investigate the mechanisms driving the observed differences in composition and P plant...... processes and 10–15% in pyrolysis whereas no reduction was observed in incineration processes. The influence on other heavy metals was less pronounced. The plant availability of P in the substrates varied from almost zero to almost 100% of the plant availability of P in the untreated sludge. Post-oxidized...