WorldWideScience

Sample records for highly pure methanol

  1. Kinetics of toluene alkylation with methanol catalyzed by pure and hybridized HZSM-5 catalysts

    KAUST Repository

    Alabi, Wahab

    2012-07-01

    A kinetic study of toluene alkylation with methanol was performed over pure HZSM-5, mordenite/ZSM-5 (hybrid of mordenite and HZSM-5), and ZM13 (composite mixture of HZSM-5 and MCM-41 at pH 13). Experimental runs were conducted using a batch fluidized bed reactor at temperatures of 300, 350 and 400 °C and reaction times of 3, 5, 7, 10, 13, 15 and 20. s. The rate of toluene methylation and toluene disproportionation were studied on the three catalysts (toluene alkylation is usually accompanied by toluene disproportionation on acid catalyst). Based on the results obtained, a simplified power law kinetic model consisting of three reactions was developed to estimate the activation energies of toluene methylation and disproportionation simultaneously. Coke formation on catalysts was accounted for using both reaction time and reactant conversion decay functions. All parameters were estimated based on quasi-steady state approximation. Estimated kinetic parameters were in good agreement with experimental results. The order of alkylation ability of the catalysts was found to be ZM13 > HZSM-5 > mordenite/ZSM-5, while the reverse is for toluene disproportionation (mordenite/ZSM-5 > HZSM-5 > ZM13). Thus, alkylation of toluene is most favorable on ZM13 due to combined effect of mesoporosity induced through its synthetic route and acid content. Toluene/MeOH molar ratio of 1:1 was most suitable for toluene alkylation reaction. © 2012 Elsevier B.V.

  2. Modelling and experimental studies on a direct methanol fuel cell working under low methanol crossover and high methanol concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, V.B.; Pinto, A.M.F.R. [Centro de Estudos de Fenomenos de Transporte, Departamento de Eng. Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Rangel, C.M. [Instituto Nacional de Energia e Geologia, Fuel Cells and Hydrogen, Estrada do Paco do Lumiar, 1649-038 Lisboa (Portugal)

    2009-08-15

    A number of issues need to be resolved before DMFC can be commercially viable such as the methanol crossover and water crossover which must be minimised in portable DMFCs. The main gain of this work is to systematically vary commercial MEA materials and check their influence on the cell performance of a direct methanol fuel cell operating at close to room temperature. A detailed experimental study on the performance of an <> developed DMFC with 25 cm{sup 2} of active membrane area, working near the ambient conditions is described. Tailored MEAs (membrane-electrode assemblies), with different structures and combinations of gas diffusion layers (GDLs), were designed and tested in order to select optimal working conditions at high methanol concentration levels without sacrificing performance. The experimental polarization and power density curves were successfully compared with the predictions of a steady state, one-dimensional model accounting for coupled heat and mass transfer, along with the electrochemical reactions occurring in the DMFC recently developed by the same authors. The influence of the anode gas diffusion layer media, the membrane thickness and the MEA properties on the cell performance are explained under the light of the predicted methanol crossover rate across the membrane. A tailored MEA build-up with the common available commercial materials was proposed to achieve relatively low methanol crossover, operating at high methanol concentrations. The use of adequate materials for the gas diffusion layers (carbon paper at the anode GDL and carbon cloth at the cathode GDL) enables the use of thinner membranes enhancing the water back diffusion which is essential to work at high methanol concentrations. (author)

  3. New Perspective of High-Pure Silicon

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@The discovery in the middle of 1950s of the semi-con ducting properties of crystalline silicon has led to the impetu ous development of electric power facilities, the sun-power industry, and particularly, the microelectronic industry. The increasing demand for the high-pure silicon requires the production of synthetic crystals. The raw material for the syn thetic crystals, the so-called technical, or metallurgical silicon, is obtained from quartzite and quartz of superior quality by means of carbon-thermal reduction of silicon using an electric arc discharge. The complexity of the technological process, high cost of the related facilities, worsening environmental pollution, and narrow-mindedness of a raw material company are attributed to the rise in price of the final product-silicon plates, resulting in the fall in the production of high-pure silicon, normally used in sun storage batteries.

  4. Development of Soybean Highly Pure Powdered Lecithin

    Institute of Scientific and Technical Information of China (English)

    Li Guihua; Gu Keren; Liang Shaohua

    2002-01-01

    This project makes use ofCondensed Soybean Phospholipids (CSP) toproduce highly pure powdered soybean lecithin.In the production technology, the first step is tode-oil by continuous y delivered mater al, higheffective mixing CSP with acetone and circularextraction. The second step is to centrifugallyseparate the lecithin miscellaneous liquid intomiscellaneous oil and solid-state lecithin withacetone. Then the mixing oil can be separatedinto crude oil and acetone by vaporization andcondensation. If the acetone contains too muchwater, it should be rectified for use circularly.Solid state lecithin with acetone can be madeinto highly pure powdered soybean lecithin(acetone insoluble matter >95% ) under thefollowing conditions: vacuum 750mmHg,temperature 60℃, time 20 minutes. Theproduction not only reaches the domestic andoversea quality index, but also has favorablehydrophilic property, which makes it becomenatural food additive and sanitarian nurture.

  5. Methanol conversion in high-rate anaerobic reactors

    NARCIS (Netherlands)

    Weijma, J.; Stams, A.J.M.

    2001-01-01

    An overview on methanol conversion in high-rate anaerobic reactors is presented, with the focus on technological as well as microbiological aspects. The simple C1-compound methanol can be degraded anaerobically in a complex way, in which methanogens, sulfate reducing bacteria and homoacetogens

  6. Development of Soybean Highly Pure Powdered Lecithin

    Institute of Scientific and Technical Information of China (English)

    LiGuihua; GuKeren; LiangShaohua

    2002-01-01

    This project makes use of Condensed Soybean Phospholipids(CSP)to produce highly pure powdered soybean lecithin.In the production technology,the first step is to de-oil by continuously delivered material,high effective mixing CSP with acetone and circular extraction.The second step is to centrifugally separate the lecithin miscellaneous liquid into miscellaneous oil and solid-state lecithin with acetone.Then the mixing oil can be separated into crude oil and acetone by vaporization and condensation.If the acetone contains too much water,it shoud be rectified for use circularly.Solid state lecithin with acetone can be made into highly pure powdered soybean lecithin (acetone insoluble matter >95%)under the following conditions:vacuum 750mmHg,temperature 60℃,time 20 minutes.The production not only reaches the domestic and oversea quality index,but also has favorable hydrophilic property,which makes it become natural food additive and sanitarian nurture.

  7. UV PHOTODESORPTION OF METHANOL IN PURE AND CO-RICH ICES: DESORPTION RATES OF THE INTACT MOLECULE AND OF THE PHOTOFRAGMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Bertin, Mathieu; Doronin, Mikhail; Philippe, Laurent; Jeseck, Pascal; Michaut, Xavier; Fillion, Jean-Hugues [LERMA, Sorbonne Universités, UPMC Univ. Paris 06, Observatoire de Paris, PSL Research University, CNRS, F-75252, Paris (France); Romanzin, Claire [LCP (UMR 8000), CNRS, Université Paris-Sud, F-91405 Orsay (France); Ligterink, Niels; Linnartz, Harold [Sackler Laboratory for Astrophysics, Leiden Observatory, Leiden University, P.O. Box 9513, NL-2300 RA Leiden (Netherlands)

    2016-02-01

    Wavelength-dependent photodesorption rates have been determined using synchrotron radiation for condensed pure and mixed methanol ice in the 7–14 eV range. The VUV photodesorption of intact methanol molecules from pure methanol ices is found to be of the order of 10{sup −5} molecules/photon, that is two orders of magnitude below what is generally used in astrochemical models. This rate gets even lower (<10{sup −6} molecules/photon) when the methanol is mixed with CO molecules in the ices. This is consistent with a picture in which photodissociation and recombination processes are at the origin of intact methanol desorption from pure CH{sub 3}OH ices. Such low rates are explained by the fact that the overall photodesorption process is dominated by the desorption of the photofragments CO, CH{sub 3}, OH, H{sub 2}CO, and CH{sub 3}O/CH{sub 2}OH, whose photodesorption rates are given in this study. Our results suggest that the role of the photodesorption as a mechanism to explain the observed gas phase abundances of methanol in cold media is probably overestimated. Nevertheless, the photodesorption of radicals from methanol-rich ices may stand at the origin of the gas phase presence of radicals such as CH{sub 3}O, therefore, opening new gas phase chemical routes for the formation of complex molecules.

  8. Bubble Dynamics for Nucleate Pool Boiling of Water, Ethanol and Methanol Pure Liquids under the Atmospheric Pressure

    Directory of Open Access Journals (Sweden)

    samane hamzekhani

    2015-01-01

    Full Text Available Bubble dynamics is the most important sub-phenomenon, which basically affects the nucleate pool boiling heat transfer coefficient. In this research, bubble departure diameter values were experimentally measured for heat fluxes up to 110 kW.m-2. Experiments were carried out for pool boiling of pure liquids, including water, ethanol and methanol on a horizontal smoothed cylinder, at atmospheric pressure. For ethanol and methanol, rigid spherical bubbles with small contact area were observed. The spherical shapes seem to be because of small diameters.For all test fluids, experimental results show that bubble diameter increases with increasing heat flux. Most predictions have a similar trend for increasing bubble diameter versus increasing heat flux. Also, the existing well-known and most common used correlations are comparatively discussedwith the present experimental data. Finally, a new model for the prediction of vapor bubble departure diameter, based on Buckingham theory, in nucleate boiling is proposed, which predicts the experimental data with a satisfactory accuracy.

  9. UV photodesorption of methanol in pure and CO-rich ices: desorption rates of the intact molecule and of the photofragments

    CERN Document Server

    Bertin, Mathieu; Doronin, Mikhail; Philippe, Laurent; Jeseck, Pascal; Litgerink, Niels; Linnartz, Harold; Michaut, Xavier; Fillion, Jean-Hugues

    2016-01-01

    Wavelength dependent photodesorption rates have been determined using synchrotron radiation, for condensed pure and mixed methanol ice in the 7 -- 14 eV range. The VUV photodesorption of intact methanol molecules from pure methanol ices is found to be of the order of 10$^{-5}$ molecules/photon, that is two orders of magnitude below what is generally used in astrochemical models. This rate gets even lower ($<$ 10$^{-6}$ molecules/photon) when the methanol is mixed with CO molecules in the ices. This is consistent with a picture in which photodissociation and recombination processes are at the origin of intact methanol desorption from pure CH$_3$OH ices. Such low rates are explained by the fact that the overall photodesorption process is dominated by the desorption of the photofragments CO, CH$_3$, OH, H$_2$CO and CH$_3$O/CH$_2$OH, whose photodesorption rates are given in this study. Our results suggest that the role of the photodesorption as a mechanism to explain the observed gas phase abundances of methan...

  10. Insights into high mass star formation from methanol maser observations

    Science.gov (United States)

    Farmer, Hontas Freeman

    2013-06-01

    We present high angular resolution data on Class I and Class II methanol masers, together with other tracers of star formation like H2O masers, ultracompact (UC) ionized hydrogen (H II) regions, and 4.5 um infrared sources, taken from the literature. The aim is to study what these data tell us about the process of high mass star formation; in particular, whether disk-outflow systems are compatible with the morphology exhibited by Class I and Class II methanol masers. Stars form in the dense cores inside molecular clouds, and while the process of the formation of stars like our Sun is reasonably well understood, details of the formation of stars with masses eight times that of our Sun or greater, the so-called high mass stars, remain a mystery. Being compact and bright sources, masers provide an excellent way to observe high mass star forming regions. In particular, Class II methanol masers are found exclusively in high mass star forming regions. Based on the positions of the Class I and II methanol and H2O masers, UCHII regions and 4.5 um infrared sources, and the center velocities (vLSR) of the Class I methanol and H2O masers, compared to the vLSR of the Class II methanol masers, we propose three disk-outflow models that may be traced by methanol masers. In all three models, we have located the Class II methanol maser near the protostar, and the Class I methanol maser in the outflow, as is known from observations during the last twenty years. In our first model, the H2O masers trace the linear extent of the outflow. In our second model, the H2O masers are located in a circumstellar disk. In our third model, the H2O masers are located in one or more outflows near the terminating shock where the outflow impacts the ambient interstellar medium. Together, these models reiterate the utility of coordinated high angular resolution observations of high mass star forming regions in maser lines and associated star formation tracers.

  11. Synthesis of highly phase pure BSCCO superconductors

    Science.gov (United States)

    Dorris, S.E.; Poeppel, R.B.; Prorok, B.C.; Lanagan, M.T.; Maroni, V.A.

    1995-11-21

    An article and method of manufacture (Bi, Pb)-Sr-Ca-Cu-O superconductor are disclosed. The superconductor is manufactured by preparing a first powdered mixture of bismuth oxide, lead oxide, strontium carbonate, calcium carbonate and copper oxide. A second powdered mixture is then prepared of strontium carbonate, calcium carbonate and copper oxide. The mixtures are calcined separately with the two mixtures then combined. The resulting combined mixture is then subjected to a powder in tube deformation and thermal processing to produce a substantially phase pure (Bi, Pb)-Sr-Ca-Cu-O superconductor. 5 figs.

  12. Novel Materials for High Efficiency Direct Methanol Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Carson, Stephen; Mountz, David; He, Wensheng; Zhang, Tao

    2013-12-31

    Direct methanol fuel cell membranes were developed using blends of different polyelectrolytes with PVDF. The membranes showed complex relationships between polyelectrolyte chemistry, morphology, and processing. Although the PVDF grade was found to have little effect on the membrane permselectivity, it does impact membrane conductivity and methanol permeation values. Other factors, such as varying the polyelectrolyte polarity, using varying crosslinking agents, and adjusting the equivalent weight of the membranes impacted methanol permeation, permselectivity, and areal resistance. We now understand, within the scope of the project work completed, how these inter-related performance properties can be tailored to achieve a balance of performance.

  13. Investigating the effect of water vapor and residual methanol on the anode of high temperature pem fuel cell

    DEFF Research Database (Denmark)

    Thomas, Sobi; Araya, Samuel Simon; Kær, Søren Knudsen

    2015-01-01

    The objective is to understand the effect of methanol and water vapor separately on a high temperature PEM fuel cell. An investigation was performed with different anode fuel compositions and results in terms of performance and impedance analyzed. During the initial 1000 h, cell was tested...... with pure hydrogen under varying current densities of 0.2 A cm-2 and 0.6 A cm-2, followed by hydrogen mixed with 15 % water vapor and then with 1 % methanol. The degradation rates at two current densities 0.2 A cm-2 and 0.6 A cm-2 were analyzed and discussed. The degradation at higher current density...... is more severe than at lower current density. However, on switching from higher to lower current density, the effect is reversible and the performance is improved. This suggests that some degradation is reversible. The addition of water vapor in the feed improves the performance at high current densities...

  14. Investigating the Effect of Water Vapor and Residual Methanol on the Anode of High Temperature PEM Fuel Cell

    DEFF Research Database (Denmark)

    Thomas, Sobi; Araya, Samuel Simon; Kær, Søren Knudsen

    The objective is to understand the effect of methanol and water vapor separately on a high temperature PEM fuel cell. An investigation was performed with different anode fuel compositions and results in terms of performance and impedance analyzed. During the initial 1000 h, cell was tested...... with pure hydrogen under varying current densities of 0.2 A cm-2 and 0.6 A cm-2, followed by hydrogen mixed with 15 % water vapor and then with 1 % methanol. The degradation rates at two current densities 0.2 A cm-2 and 0.6 A cm-2 were analyzed and discussed. The degradation at higher current density...... is more severe than at lower current density. However, on switching from higher to lower current density, the effect is reversible and the performance is improved. This suggests that some degradation is reversible. The addition of water vapor in the feed improves the performance at high current densities...

  15. Impregnated membranes for direct methanol fuel cells at high methanol concentrations

    NARCIS (Netherlands)

    Yildirim, M. Hakan; Schwarz, Alexander; Stamatialis, Dimitrios F.; Wessling, Matthias

    2009-01-01

    Sulfonated poly(phthalazinone ether ketone) (SPPEK) impregnated Solupor® microporous film (SPPEK–PE) and pure SPPEK membranes with two different ion-exchange capacities (IECs) were prepared and characterized for use in DMFC applications. Swelling, proton conductivity, diffusion and DMFC experiments

  16. Impregnated membranes for direct methanol fuel cells at high methanol concentrations

    NARCIS (Netherlands)

    Yildirim, M.H.; Schwarz, Alexander; Stamatialis, Dimitrios; Wessling, Matthias

    2009-01-01

    Sulfonated poly(phthalazinone ether ketone) (SPPEK) impregnated Solupor® microporous film (SPPEK–PE) and pure SPPEK membranes with two different ion-exchange capacities (IECs) were prepared and characterized for use in DMFC applications. Swelling, proton conductivity, diffusion and DMFC experiments

  17. Direct Observation of High Photoresponsivity in Pure Graphene Photodetectors

    Science.gov (United States)

    Liu, Yanping; Xia, Qinglin; He, Jun; Liu, Zongwen

    2017-02-01

    Ultrafast and broad spectral bandwidth photodetectors are desirable attributable to their unique bandstructures. Photodetectors based on graphene have great potential due to graphene's outstanding optical and electrical properties. However, the highest reported values of the photoresponsivity of pure graphene are less than 10 mA/W at room temperature, which significantly limits its potential applications. Here, we report a photoresponsivity of 32 A/W in pure monolayer graphene photodetectors, an improvement of over one order of magnitude for functional graphene nanostructures (devices can be attributed to the high sensitivity of graphene's resistivity to a local change of the electric field induced by photo-excited carriers generated in the light-doping substrate. This dramatically increases the feasibility of using graphene for the next generation of photodetectors.

  18. Highly methanol-tolerant platinum electrocatalyst derived from poly(vinylpoyrrolidone) coating

    Science.gov (United States)

    Yang, Zehui; Ling, Ying; Zhang, Yunfeng; Yang, Ming

    2017-02-01

    The design and fabrication of a methanol-tolerant electrocatalyst is still one of the most important issues in direct methanol fuel cells (DMFCs). Here, we focus on the design of a cathodic electrocatalyst in DMFCs and describe a new methanol-tolerant electrocatalyst fabricated from poly(vinylpyrrolidone) (PVP) coating on platinum nanoparticles assisted by hydrogen bonding between PVP and polybenzimidazole (PBI). The PVP layer has a negligible effect on the oxygen reduction reaction (ORR) activity, while the methanol oxidation reaction is retarded by the PVP layer. The PVP-coated electrocatalyst shows higher ORR activity under various methanol concentrations in the electrolyte, suggesting that the PVP-coated electrocatalyst has a higher methanol tolerance. Also, the PVP-coated electrocatalyst loses only 14% of the electrochemical surface area after 5000 potential cycles from 0.6-1.0 V versus the reversible hydrogen electrode, indicating better Pt stability than non-coated (27%) and commercial (38%) electrocatalysts due to the unique sandwich structure formed by the PVP and PBI. The power density of the PVP-coated electrocatalyst is four to five times higher compared to non-coated and commercial electrocatalysts with 12 M methanol feeding to the anode side, respectively. PVP coating is important for the enhancement of Pt stability and methanol tolerance. This study offers a new method for preparing a low-cost and high-methanol-tolerant Pt electrocatalyst, and useful information for real DMFC application to eliminate the methanol crossover problem in the cathode side.

  19. Preparation for Ultra High Pure Indium Metal for Optoelectronic Applications

    Directory of Open Access Journals (Sweden)

    Shashwat V. Joshi

    2014-11-01

    Full Text Available Ultra high pure Indium metal is extensively used in optoelectronic devices. Indium and its alloys become potential candidates in aerospace, defense and communication sectors. Purification of Indium has been done by Instrolec-200 Refiner followed by Directional Melting/ Freezing and Solidification Systems. Major targeted impurities are Metallic impurities Ag, Al, As, Bi, Ca, Cu, Fe, Ga, Ge, Mg, Pb, Sb, Si, Sn, and Zn. Purified Indium is characterized by analytical techniques Inductively Coupled Plasma- Optical Emission Spectrophotometry and Inductively Coupled Plasma- Mass Spectrometry.

  20. Isolating highly pure rat spermatogonial stem cells in culture.

    Science.gov (United States)

    Hamra, F Kent; Chapman, Karen M; Wu, Zhuoru; Garbers, David L

    2008-01-01

    Methods are detailed for isolating highly pure populations of spermatogonial stem cells from primary cultures of testis cells prepared from 22- to 24-day-old rats. The procedure is based on the principle that testicular somatic cells bind tightly to plastic and collagen matrices when cultured in serum-containing medium, whereas spermatogonia and spermatocytes do not bind to plastic or collagen when cultured in serum-containing medium. The collagen-non-binding testis cells obtained using these procedures are thus approx. 97% pure spermatogenic cells. Stem spermatogonia are then easily isolated from the purified spermatogenic population during a short incubation step in culture on laminin matrix. The spermatogenic cells that bind to laminin are more than 90% undifferentiated, type A spermatogonia and are greatly enriched in genetically modifiable stem cells that can develop into functional spermatozoa. This method does not require flow cytometry and can also be applied to obtain enriched cultures of mouse spermatogonial stem cells. The isolated spermatogonia provide a highly potent and effective source of stem cells that have been used to initiate in vitro and in vivo culture studies on spermatogenesis.

  1. Silica based composite membranes for methanol fuel cells operating at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, A.; Guzman, C.; Peza-Ledesma, C.; Godinez, Luis A.; Nava, R.; Duron-Torres, S.M.; Ledesma-Garcia, J.; Arriaga, L.G.

    2011-01-15

    Direct methanol fuel cells (DMFCs) are seen as an alternative energy source for several applications, particularly portable power sources. Nafion membranes constitute a well known proton exchange system for DMFC systems due to their convenient electrochemical, mechanical and thermal stability and high proton conductivity properties. But there are problems currently associated with the direct methanol fuel cell technology. Intensive efforts to decrease the methanol crossover are focused mainly on the development of new polymer electrolyte membranes. In this study, Nafion polymer was modified by means of the incorporation of inorganic oxides with different structural properties (SBA-15 and SiO2), both prepared by sol-gel method in order to increase the proton conductivity at high temperature of fuel cell and to contribute decrementing the methanol crossover effect. Composite membranes based in inorganic fillers showed a significant decrease in the concentration of methanol permeation.

  2. Production of highly pure einsteinium and fermium preparations

    Energy Technology Data Exchange (ETDEWEB)

    Andreev, O.I.; Tarasov, V.A.; Zotov, E.A.; Baranov, A.Yu. [Federal State Unitary Enterprise ' ' State Scientific Center of Russian Federation Research Institute of Atomic Reactors' ' (Russian Federation)

    2004-07-01

    Highly pure einsteinium and fermium preparations are in increased demand due to the progress of the following fields of modern sciences: Fundamental and applied nuclear physics. Heavy actinides are necessary for detailed study of structure and decay of a nucleus, as well as initial material both for nuclear synthesis of new superheavy elements and for manufacturing radioactive radiation sources. Fundamental and applied radiochemistry. Einsteinium and fermium preparations are required to investigate chemical properties of these hard-to-obtain elements and to improve technology of their recovery and purification. Nuclear medicine. Biologically active compounds labeled with alpha- emitting einsteinium and fermium may be applied in prospect for a radioimmunotherapy of oncological diseases. The principal method of einsteinium and fermium production is irradiation of curium or californium isotopes in a high-flux nuclear reactor. Large-scale production of transplutonium elements at RIAR enables also to produce regularly significant quantities of einsteinium and fermium. (orig.)

  3. Performance and endurance of a high temperature PEM fuel cell operated on methanol reformate

    DEFF Research Database (Denmark)

    Araya, Samuel Simon; Grigoras, Ionela; Zhou, Fan

    2014-01-01

    This paper analyzes the effects of methanol and water vapor on the performance of a high temperature proton exchange membrane fuel cell (HT-PEMFC) at varying temperatures, ranging from 140 °C to 180 °C. For the study, a H3PO4 – doped polybenzimidazole (PBI) – based membrane electrode assembly (MEA......) of 45 cm2 active surface area from BASF was employed. The study showed overall negligible effects of methanol-water vapor mixture slips on performance, even at relatively low simulated steam methanol reforming conversion of 90%, which corresponds to 3% methanol vapor by volume in the anode gas feed....... Temperature on the other hand has significant impact on the performance of an HT-PEMFC. To assess the effects of methanol-water vapor mixture alone, CO2 and CO are not considered in these tests. The analysis is based on polarization curves and impedance spectra registered for all the test points. After...

  4. Methanol masers as tools to study high-mass star formation

    CERN Document Server

    Pestalozzi, Michele

    2007-01-01

    In this contribution I will attempt to show that the study of galactic 6.7 and 12.2GHz methanol masers themselves, as opposed to the use of methanol masers as signposts, can yield important conclusions contributing to the understanding of high-mass star formation. Due to their exclusive association with star formation, methanol masers are the best tools to do this, and their large number allows to probe the entire Galaxy. In particular I will focus on the determination of the luminosity function of methanol masers and on the determination of an unambiguous signature for a circumstellar masing disc seen edge-on. Finally I will try to point out some future fields of research in the study of methanol masers.

  5. The lattice parameter of highly pure silicon single crystals

    Science.gov (United States)

    Becker, P.; Scyfried, P.; Siegert, H.

    1982-08-01

    From crystal to crystal comparison, the d 220 lattice spacing in PERFX and WASO silicon crystals used in the only two existing absolute measurements have been found to be equal within ±2×10-7 d 220. This demonstrates that generic variabilities of the two crystals account only for a small part of the 1.8×10-6 d 220 difference in the two absolute measurements. In a new series of 336 single measurements, our d 220 value reported recently has been confirmed within ±2×10-8 d 220. From these results we derive the following lattice parameter for highly pure silicon single crystals: a 0=(543 102.018±0.034) fm (at 22.5°C, in vacuum).

  6. High specific power, direct methanol fuel cell stack

    Science.gov (United States)

    Ramsey, John C.; Wilson, Mahlon S.

    2007-05-08

    The present invention is a fuel cell stack including at least one direct methanol fuel cell. A cathode manifold is used to convey ambient air to each fuel cell, and an anode manifold is used to convey liquid methanol fuel to each fuel cell. Tie-bolt penetrations and tie-bolts are spaced evenly around the perimeter to hold the fuel cell stack together. Each fuel cell uses two graphite-based plates. One plate includes a cathode active area that is defined by serpentine channels connecting the inlet manifold with an integral flow restrictor to the outlet manifold. The other plate includes an anode active area defined by serpentine channels connecting the inlet and outlet of the anode manifold. Located between the two plates is the fuel cell active region.

  7. Dispersion Performance of Methanol-Diesel Emulsiifed Fuel Prepared by High Gravity Technology

    Institute of Scientific and Technical Information of China (English)

    Jiao Weizhou; Li Jing; Liu Youzhi; Zhang Qiaoling; Liu Wenli; Xu Chengcheng; Guo Liang

    2014-01-01

    A new continuous process for preparing methanol-diesel emulsified fuel with an Impinging Stream-Rotating Packed Bed is proposed. The droplet size of dispersed phase (methanol) of the emulsiifed fuel has a signiifcant effect on the combustion of methanol-diesel emulsiifed fuel. In this paper, the methanol-diesel emulsiifed fuel uses diesel as the continu-ous phase and methanol as the dispersed phase. The Sauter mean diameter of the dispersed phase of methanol-diesel emulsi-ifed fuel was characterized with microphotography and arithmetic method. The experimental result showed that the Sauter mean diameter of the dispersed phase, which was decreased with the augmentation of the high gravity factor, liquid lfow rate and emulsiifer dosage, was inversely proportional to the methanol content. The Sauter mean diameter of the dispersed phase can be controlled and adjusted in the range of 12-40μm through the change of operating conditions. The correlative expressions of the Sauter mean diameter of emulsiifed fuel were obtained and the calculated values agreed well with the ex-perimental values.

  8. Methanol masers Reliable tracers of the early stages of high-mass star formation

    CERN Document Server

    Ellingsen, S P

    2006-01-01

    The GLIMPSE and MSX surveys have been used to examine the mid-infrared properties of a statistically complete sample of 6.7 GHz methanol masers. The GLIMPSE point sources associated with methanol masers are clearly distinguished from the majority, typically having extremely red mid-infrared colors, similar to those expected of low-mass class 0 young stellar objects. The intensity of the GLIMPSE sources associated with methanol masers is typically 4 magnitudes brighter at 8.0 micron than at 3.6 micron. Targeted searches towards GLIMPSE point sources with [3.6]-[4.5] > 1.3 and an 8.0 micron magnitude less than 10 will detect more than 80% of class II methanol masers. Many of the methanol masers are associated with sources within infrared dark clouds (IRDC) which are believed to mark regions where high-mass star formation is in its very early stages. The presence of class II methanol masers in a significant fraction of IRDC suggests that high-mass star formation is common in these regions. Different maser specie...

  9. Methanol-Tolerant Platinum-Palladium Catalyst Supported on Nitrogen-Doped Carbon Nanofiber for High Concentration Direct Methanol Fuel Cells

    Directory of Open Access Journals (Sweden)

    Jiyoung Kim

    2016-08-01

    Full Text Available Pt-Pd catalyst supported on nitrogen-doped carbon nanofiber (N-CNF was prepared and evaluated as a cathode electrode of the direct methanol fuel cell (DMFC. The N-CNF, which was directly synthesized by the catalytic chemical vapor deposition from acetonitrile at 640 °C, was verified as having a change of electrochemical surface properties such as oxygen reduction reaction (ORR activities and the electrochemical double layer compared with common carbon black (CB. To attain the competitive oxygen reduction reaction activity with methanol tolerance, the Pt and Pd metals were supported on the CB or the N-CNF. The physical and electrochemical characteristics of the N-CNF–supported Pt-Pd catalyst were examined and compared with catalyst supported on the CB. In addition, DMFC single cells using these catalysts as the cathode electrode were applied to obtain I-V polarization curves and constant current operating performances with high-concentration methanol as the fuel. Pt-Pd catalysts had obvious ORR activity even in the presence of methanol. The higher power density was obtained at all the methanol concentrations when it applied to the membrane electrode assembly (MEA of the DMFC. When the N-CNF is used as the catalyst support material, a better performance with high-concentration methanol is expected.

  10. High-rate, high-yield production of methanol by ammonia-oxidizing bacteria.

    Science.gov (United States)

    Taher, Edris; Chandran, Kartik

    2013-04-02

    The overall goal of this study was to develop an appropriate biological process for achieving autotrophic conversion of methane (CH(4)) to methanol (CH3OH). In this study, we employed ammonia-oxidizing bacteria (AOB) to selectively and partially oxidize CH(4) to CH(3)OH. In fed-batch reactors using mixed nitrifying enrichment cultures from a continuous bioreactor, up to 59.89 ± 1.12 mg COD/L of CH(3)OH was produced within an incubation time of 7 h, which is approximately ten times the yield obtained previously using pure cultures of Nitrosomonas europaea. The maximum specific rate of CH(4) to CH(3)OH conversion obtained during this study was 0.82 mg CH(3)OH COD/mg AOB biomass COD-d, which is 1.5 times the highest value reported with pure cultures. Notwithstanding these positive results, CH(4) oxidation to CH(3)OH by AOB was inhibited by NH(3) (the primary substrate for the oxidative enzyme, ammonia monooxygenase, AMO) as well as the product, CH(3)OH, itself. Further, oxidation of CH(4) to CH(3)OH by AOB was also limited by reducing equivalents supply, which could be overcome by externally supplying hydroxylamine (NH(2)OH) as an electron donor. Therefore, a potential optimum design for promoting CH(4) to CH(3)OH oxidation by AOB could involve supplying NH(3) (needed to maintain AMO activity) uncoupled from the supply of NH(2)OH and CH(4). Partial oxidation of CH(4)-containing gases to CH3OH by AOB represents an attractive platform for the conversion of a gaseous mixture to an aqueous compound, which could be used as a commodity chemical. Alternately, the nitrate and CH(3) OH thus produced could be channeled to a downstream anoxic zone in a biological nitrogen removal process to effect nitrate reduction to N(2), using an internally produced organic electron donor.

  11. Bayberry-like ZnO/MFI zeolite as high performance methanol-to-aromatics catalyst.

    Science.gov (United States)

    Wang, Ning; Qian, Weizhong; Shen, Kui; Su, Chang; Wei, Fei

    2016-02-01

    Unique bayberry-like MFI zeolites are synthesized through a quasi-solid-state crystallization approach. This hierarchical zeolite structure has a relatively thick shell, densely grown nanocrystals with an ordered packed channel, high mechanical stability, high surface area and a low Si/Al ratio. Its catalytic efficiency for methanol-to-aromatics is significantly higher than that of conventional MFI zeolites.

  12. TiO2 Nanotube-Carbon (TNT-C) as Support for Pt-based Catalyst for High Methanol Oxidation Reaction in Direct Methanol Fuel Cell.

    Science.gov (United States)

    Abdullah, M; Kamarudin, S K; Shyuan, L K

    2016-12-01

    In this study, TiO2 nanotubes (TNTs) were synthesized via a hydrothermal method using highly concentrated NaOH solutions varying from 6 to 12 M at 180 °C for 48 h. The effects of the NaOH concentration and the TNT crystal structure on the performance for methanol oxidation were investigated to determine the best catalyst support for Pt-based catalysts. The results showed that TNTs produced with 10 M NaOH exhibited a length and a diameter of 550 and 70 nm, respectively; these TNTs showed the best nanotube structure and were further used as catalyst supports for a Pt-based catalyst in a direct methanol fuel cell. The synthesized TNT and Pt-based catalysts were analysed by FESEM, TEM, BET, EDX, XRD and FTIR. The electrochemical performance of the catalysts was investigated using cyclic voltammetry (CV) and chronoamperometric (CA) analysis to further understand the methanol oxidation in the direct methanol fuel cell (DMFC). Finally, the result proves that Pt-Ru/TNT-C catalyst shows high performance in methanol oxidation as the highest current density achieved at 3.3 mA/cm(2) (normalised by electrochemically active surface area) and high catalyst tolerance towards poisoning species was established.

  13. TiO2 Nanotube-Carbon (TNT-C) as Support for Pt-based Catalyst for High Methanol Oxidation Reaction in Direct Methanol Fuel Cell

    Science.gov (United States)

    Abdullah, M.; Kamarudin, S. K.; Shyuan, L. K.

    2016-12-01

    In this study, TiO2 nanotubes (TNTs) were synthesized via a hydrothermal method using highly concentrated NaOH solutions varying from 6 to 12 M at 180 °C for 48 h. The effects of the NaOH concentration and the TNT crystal structure on the performance for methanol oxidation were investigated to determine the best catalyst support for Pt-based catalysts. The results showed that TNTs produced with 10 M NaOH exhibited a length and a diameter of 550 and 70 nm, respectively; these TNTs showed the best nanotube structure and were further used as catalyst supports for a Pt-based catalyst in a direct methanol fuel cell. The synthesized TNT and Pt-based catalysts were analysed by FESEM, TEM, BET, EDX, XRD and FTIR. The electrochemical performance of the catalysts was investigated using cyclic voltammetry (CV) and chronoamperometric (CA) analysis to further understand the methanol oxidation in the direct methanol fuel cell (DMFC). Finally, the result proves that Pt-Ru/TNT-C catalyst shows high performance in methanol oxidation as the highest current density achieved at 3.3 mA/cm2 (normalised by electrochemically active surface area) and high catalyst tolerance towards poisoning species was established.

  14. High-temperature passive direct methanol fuel cells operating with concentrated fuels

    Science.gov (United States)

    Zhao, Xuxin; Yuan, Wenxiang; Wu, Qixing; Sun, Hongyuan; Luo, Zhongkuan; Fu, Huide

    2015-01-01

    Conventionally, passive direct methanol fuel cells (DMFC) are fed with diluted methanol solutions and can hardly be operated at elevated temperatures (>120 °C) because the ionic conductivity of Nafion-type proton exchange membranes depends strongly on water content. Such a system design would limit its energy density and power density in mobile applications. In this communication, a passive vapor feed DMFC capable of operating with concentrated fuels at high temperatures is reported. The passive DMFC proposed in this work consists of a fuel reservoir, a perforated silicone sheet, a vapor chamber, two current collectors and a membrane electrode assembly (MEA) based on a phosphoric acid doped polybenzimidazole (PBI) membrane. The experimental results reveal that the methanol crossover through a PBI membrane is substantially low when compared with the Nafion membranes and the PBI-based passive DMFC can yield a peak power density of 37.2 mW cm-2 and 22.1 mW cm-2 at 180 °C when 16 M methanol solutions and neat methanol are used respectively. In addition, the 132 h discharge test indicates that the performance of this new DMFC is quite stable and no obvious performance degradation is observed after activation, showing its promising applications in portable power sources.

  15. Thermophilic sulfate reduction and methanogenesis with methanol in a high rate anaerobic reactor

    Energy Technology Data Exchange (ETDEWEB)

    Weijma, J.; Stams, A.J.M.; Pol, L.W.H.; Lettinga, G.

    2000-02-05

    Sulfate reduction outcompeted methanogenesis at 65 C and pH 7.5 in methanol and sulfate-fed expanded granular sludge bed reactors operated at hydraulic retention times (HRT) of 14 and 2.5 h, both under methanol-limiting and methanol-overloading conditions. After 100 and 50 days for the reactors operated at 14 and 3.5 h, respectively, sulfide production accounted for 80% of the methanol-COD consumed by the sludge. The specific methanogenic activity on methanol of the sludge from a reactor operated at HRTs of down to 3.5 h for a period of 4 months gradually decreased from 0.83 gCOD {sm_bullet} gVSS{sup {minus}1} {sm_bullet} day{sup {minus}1} at the start to a value of less than 0.05 gCOD {sm_bullet} gVSS{sup {minus}1} {sm_bullet} day{sup {minus}1}, showing that the relative number of methanogens decreased and eventually became very low. By contrast, the increase of the specific sulfidogenic activity of sludge from 0.22 gCOD {sm_bullet} gVSS{sup {minus}1} {sm_bullet} day{sup {minus}1} to a final value of 1.05 gCOD {sm_bullet} gVSS{sup {minus}1} {sm_bullet} day{sup {minus}1} showed that sulfate reducing bacteria were enriched. Methanol degradation by a methanogenic culture obtained from a reactor by serial dilution of the sludge was inhibited in the presence of vancomycin, indicating that methanogenesis directly from methanogenic culture obtained from a reactor by serial dilution of the sludge was inhibited in the presence of vancomycin, indicating that methanogenesis directly from methanol was not important. H{sub 2}/CO{sub 2} and formate, but not acetate, were degraded to methane in the presence of vancomycin. These results indicated that methanol degradation to methane occurs via the intermediates H{sub 2}/CO{sub 2} and formate. The high and low specific methanogenic activity of sludge on H{sub 2}/CO{sub 2} and formate, respectively, indicated that the former substrate probably acts as the main electron donor for the methanogens during methanol degradation. As

  16. Modeling and Experimental Studies on Phase and Chemical Equilibria in High-Pressure Methanol Synthesis

    NARCIS (Netherlands)

    van Bennekom, Joost G.; Winkelman, Jozef G. M.; Venderbosch, Robertus H.; Nieland, Sebastiaan D. G. B.; Heeres, Hero J.

    2012-01-01

    A solution method was developed to calculate the simultaneous phase and chemical equilibria in high-pressure methanol synthesis (P = 20 MPa, 463

  17. Effectiveness of hemodialysis with high-flux polysulfone membrane in the treatment of life-threatening methanol intoxication.

    Science.gov (United States)

    Peces, Ramón; Alvarez, Rafael

    2002-02-01

    Methanol poisoning may result in metabolic acidosis, blindness and death. In this report, we describe a case of life-threatening methanol intoxication in a 44-year-old man who was treated successfully with supportive care, ethanol infusion, folic acid and early hemodialysis with a high-flux polysulfone dialyzer. We conclude that hemodialysis as implemented in this case is a safe and effective approach to the management of methanol poisoning. Copyright 2002 S. Karger AG, Basel

  18. Experimental study to distinguish the effects of methanol slip and water vapour on a high temperature PEM fuel cell at different operating conditions

    DEFF Research Database (Denmark)

    Thomas, Sobi; Vang, Jakob Rabjerg; Araya, Samuel Simon

    2017-01-01

    The objective of this paper is to separate out the effects of methanol and water vapour on a high temperature polymer electrolyte membrane fuel cell under different temperatures (160°C and 180°C) and current densities (0.2Acm-2, 0.4Acm-2 and 0.6Acm-2). The degradation rates at the different current...... to the anode after pure hydrogen operation at 180°C. A decrease in the total resistance corresponding to the voltage improvement is observed from the impedance spectra. There is minimal variation in performance with the introduction of 3% and 5% methanol along with water vapour in the anode feed at all current...

  19. In situ crystallization of ionic liquid [Emim][PF6] from methanol solution under high pressure.

    Science.gov (United States)

    Li, Haining; Su, Lei; Zhu, Xiang; Cheng, Xuerui; Yang, Kun; Yang, Guoqiang

    2014-07-24

    The solubility of 1-ethyl-3-methylimidazolium hexafluorophosphate ([Emim][PF6]) in methanol under high pressure is newly measured quantitatively according to the correlation between the ratios of Raman intensity and the concentrations. In situ crystallization and cation conformation of [Emim][PF6] from methanol solution under high pressure have been investigated by using Raman spectroscopy in detail. Remarkably, crystal polymorphism was observed and two crystalline phases (phases I and II) coexisted under high pressure up to ∼ 1.4 GPa. However, only phase II was obtained by recrystallization at ∼ 2 GPa. Our findings may facilitate the development of an effective way for crystallization and purification of ionic liquids under high pressure.

  20. Biosynthesis of poly-3-hydroxybutyrate with a high molecular weight by methanotroph from methane and methanol

    Institute of Scientific and Technical Information of China (English)

    Yingxin Zhang; Jiaying Xin; Linlin Chen; Hao Song; Chungu Xia

    2008-01-01

    Poly-3-hydroxybutyrate (PHB) can be produced by various species of bacteria. Among the possible carbon sources, both methane and methanol could be a suitable substrate for the production of PHB. Methane is cheap and plentiful not only as natural gas, but also as biogas. Methanol can also maintain methanotrophic activity in some conditions. The methanotrophic strain Methylosinus trichosporium IMV3011 can accumulate PHB with methane and methanol in a brief nonsterile process. Liquid methanol (0.1%) was added to improve the oxidization of methane. The studies were carried out using shake flasks. Cultivation was performed in two stages: a continuous growth phase and a PHB accumulation phase under the conditions short of essential nutrients (ammonium, nitrate, phosphorus, copper, iron (III), magnesium or ethylenediamine tetraacetate (EDTA)) in batch culture. It was found that the most suitable growth time for the cell is 144 h. Then an optimized culture condition for second stage was determined, in which the PHB concentration could be much increased to 0.6 g/L. In order to increase PHB content, citric acid was added as an inhibitor of tricarboxylic acid cycle (TCA). It was found that citric acid is favorable for the PHB accumulation, and the PHB yield was increased to 40% (w/w) from the initial yield of 12% (w/w) after nutrient deficiency cultivation. The PHB produced is of very high quality with molecular weight up to 1.5 ×106Da.

  1. Growth of Bacillus methanolicus in 2 M methanol at 50 °C: the effect of high methanol concentration on gene regulation of enzymes involved in formaldehyde detoxification by the ribulose monophosphate pathway.

    Science.gov (United States)

    Bozdag, Ahmet; Komives, Claire; Flickinger, Michael C

    2015-07-01

    Bacillus methanolicus MGA3 is a Gram-positive aerobic methylotroph growing optimally at 50-53°C. Methylotrophy in B. methanolicus is encoded on pBM19 and by two chromosomal copies of the methanol dehydrogenase (mdh), hexulose phosphate synthase (hps) and phosphohexuloisomerase (phi) genes. However, there are no published studies on the regulation of methylotrophy or the dominant mechanism of detoxification of intracellular formaldehyde in response to high methanol concentration. The µ max of B. methanolicus MGA3 was assessed on methanol, mannitol and glucose. B. methanolicus achieved a µ max at 25 mM initial methanol of 0.65 ± 0.007 h(-1), which decreased to 0.231 ± 0.004 h(-1) at 2 M initial methanol. Slow growth was also observed with initial methanol concentrations of >2 M. The µ max on mannitol and glucose are 0.532 ± 0.002 and 0.336 ± 0.003 h(-1), respectively. Spiking cultures with additional methanol (100 mM) did not disturb the growth rate of methanol-grown cells, whereas, a 50 mM methanol spike halted the growth in mannitol. Surprisingly, growth in methanol was inhibited by 1 mM formaldehyde, while mannitol-grown cells tolerated 2 mM. Moreover, mannitol-grown cells removed formaldehyde faster than methanol-grown cells. Further, we show that methanol oxidation in B. methanolicus MGA3 is mainly carried out by the pBM19-encoded mdh. Formaldehyde and formate addition down-regulate the mdh and hps genes in methanol-grown cells. Similarly, they down-regulate mdh genes in mannitol-grown cells, but up-regulate hps. Phosphofructokinase (pfk) is up-regulated in both methanol and mannitol-grown cells, which suggests that pfk may be a possible synthetic methylotrophy target to reduce formaldehyde growth toxicity at high methanol concentrations.

  2. Why does high pressure destroy co-non-solvency of PNIPAm in aqueous methanol?

    Science.gov (United States)

    de Oliveira, Tiago E.; Netz, Paulo A.; Mukherji, Debashish; Kremer, Kurt

    It is well known that poly(N-isopropylacrylamide) (PNIPAm) exhibits an interesting, yet puzzling, phenomenon of co-non-solvency. Co-non-solvency occurs when two competing good solvents for PNIPAm, such as water and alcohol, are mixed together. As a result, the same PNIPAm collapses within intermediate mixing ratios. This complex conformational transition is driven by preferential binding of methanol with PNIPAm. Interestingly, co-non-solvency can be destroyed when applying high hydrostatic pressures. In this work, using a large scale molecular dynamics simulation employing high pressures, we propose a microscopic picture behind the suppression of the co-non-solvency phenomenon. Based on thermodynamic and structural analysis, our results suggest that the preferential binding of methanol with PNIPAm gets partially lost at high pressures, making the background fluid reasonably homogeneous for the polymer. This is consistent with the hypothesis that the co-non-solvency phenomenon is driven by preferential binding and is not based on depletion effects.

  3. High Performance and Cost-Effective Direct Methanol Fuel Cells: Fe-N-C Methanol-Tolerant Oxygen Reduction Reaction Catalysts.

    Science.gov (United States)

    Sebastián, David; Serov, Alexey; Artyushkova, Kateryna; Gordon, Jonathan; Atanassov, Plamen; Aricò, Antonino S; Baglio, Vincenzo

    2016-08-09

    Direct methanol fuel cells (DMFCs) offer great advantages for the supply of power with high efficiency and large energy density. The search for a cost-effective, active, stable and methanol-tolerant catalyst for the oxygen reduction reaction (ORR) is still a great challenge. In this work, platinum group metal-free (PGM-free) catalysts based on Fe-N-C are investigated in acidic medium. Post-treatment of the catalyst improves the ORR activity compared with previously published PGM-free formulations and shows an excellent tolerance to the presence of methanol. The feasibility for application in DMFC under a wide range of operating conditions is demonstrated, with a maximum power density of approximately 50 mW cm(-2) and a negligible methanol crossover effect on the performance. A review of the most recent PGM-free cathode formulations for DMFC indicates that this formulation leads to the highest performance at a low membrane-electrode assembly (MEA) cost. Moreover, a 100 h durability test in DMFC shows suitable applicability, with a similar performance-time behavior compared to common MEAs based on Pt cathodes.

  4. High strain rate behavior of pure metals at elevated temperature

    Science.gov (United States)

    Testa, Gabriel; Bonora, Nicola; Ruggiero, Andrew; Iannitti, Gianluca; Domenico, Gentile

    2013-06-01

    In many applications and technology processes, such as stamping, forging, hot working etc., metals and alloys are subjected to elevated temperature and high strain rate deformation process. Characterization tests, such as quasistatic and dynamic tension or compression test, and validation tests, such as Taylor impact and DTE - dynamic tensile extrusion -, provide the experimental base of data for constitutive model validation and material parameters identification. Testing material at high strain rate and temperature requires dedicated equipment. In this work, both tensile Hopkinson bar and light gas gun where modified in order to allow material testing under sample controlled temperature conditions. Dynamic tension tests and Taylor impact tests, at different temperatures, on high purity copper (99.98%), tungsten (99.95%) and 316L stainless steel were performed. The accuracy of several constitutive models (Johnson and Cook, Zerilli-Armstrong, etc.) in predicting the observed material response was verified by means of extensive finite element analysis (FEA).

  5. Microwave-assisted synthesis of high-loading, highly dispersed Pt/carbon aerogel catalyst for direct methanol fuel cell

    Indian Academy of Sciences (India)

    Zhijun Guo; Hong Zhu; Xinwei Zhang; Fanghui Wang; Yubao Guo; Yongsheng Wei

    2011-06-01

    A Pt supported on carbon aerogel catalyst has been synthesized by the microwave-assisted polyol process. The Pt supported on carbon aerogel catalyst was characterized by high resolution transmission electron microscopy and X-ray diffraction. The results show a uniform dispersion of spherical Pt nanoparticles 2.5–3.0 nm in diameter. Cyclic voltammetry and chronoamperometry were used to evaluate the electrocatalytic activity of the Pt/carbon aerogel catalyst for methanol oxidation at room temperature. The Pt/carbon aerogel catalyst shows higher electrochemical catalytic activity and stability for methanol oxidation than a commercial Pt/C catalyst of the same Pt loading.

  6. Twin Interactions in Pure Ti Under High Strain Rate Compression

    Science.gov (United States)

    Zhou, Ping; Xiao, Dawu; Jiang, Chunli; Sang, Ge; Zou, Dongli

    2017-01-01

    Twin interactions associated with {11 overline{2} 1} (E2) twins in titanium deformed by high strain rate ( 2600 s-1) compression were studied using electron backscatter diffraction technique. Three types of twins, {10 overline{1} 2} (E1), {11 overline{2} 2} (C1), and {11 overline{2} 4} (C3), were observed to interact with the preformed E2 twins in four parent grains. The E1 variants nucleated at twin boundaries of some E2 variants. And the C3 twins were originated from the intersection of C1 and E2. The selection of twin variant was investigated by the Schmid factors (SFs) and the twinning shear displacement gradient tensors (DGTs) calculations. The results show that twin variants that did not follow the Schmid law were more frequently observed under high strain rate deformation than quasi-static deformation. Among these low-SF active variants, 73 pct (8 out of 11) can be interpreted by DGT. Besides, 26 variants that have SF values close to or higher than their active counterparts were absent. Factors that may affect the twin variant selections were discussed.

  7. Preparation of Pt Ag alloy nanoisland/graphene hybrid composites and its high stability and catalytic activity in methanol electro-oxidation

    Directory of Open Access Journals (Sweden)

    Feng Lili

    2011-01-01

    Full Text Available Abstract In this article, PtAg alloy nanoislands/graphene hybrid composites were prepared based on the self-organization of Au@PtAg nanorods on graphene sheets. Graphite oxides (GO were prepared and separated to individual sheets using Hummer's method. Graphene nano-sheets were prepared by chemical reduction with hydrazine. The prepared PtAg alloy nanomaterial and the hybrid composites with graphene were characterized by SEM, TEM, and zeta potential measurements. It is confirmed that the prepared Au@PtAg alloy nanorods/graphene hybrid composites own good catalytic function for methanol electro-oxidation by cyclic voltammograms measurements, and exhibited higher catalytic activity and more stability than pure Au@Pt nanorods and Au@AgPt alloy nanorods. In conclusion, the prepared PtAg alloy nanoislands/graphene hybrid composites own high stability and catalytic activity in methanol electro-oxidation, so that it is one kind of high-performance catalyst, and has great potential in applications such as methanol fuel cells in near future.

  8. Study on Highly Active Catalysts and a Once-Through Process for Methanol Synthesis from Syngas

    Institute of Scientific and Technical Information of China (English)

    Xin Dong; Bingshun Shen; Hongbin Zhang; Guodong Lin; Youzhu Yuan

    2003-01-01

    Highly active CNT-promoted co-precipitated Cu-ZnO-Al2O3 catalysts, symbolized asCuiZnjAlk-x%CNTs, were prepared, and their catalytic activity for once-through methanol synthesis fromsyngas was investigated. The results illustrated that, under the reaction conditions (at 493 K, 5.0 MPa, thevolume ratio of H2/CO/CO2/N2= 62/30/5/3, GHSV= 4000 h-1), the observed single-pass CO-conversionand methanol-STY over a Cu6Zn3Al1-12.5%CNTs catalyst reached 64% and 1210 mg/(h@g), which wasabout 68% and 66% higher than those (38% and 730 mg/(h@g)) over the corresponding CNT-free catalyst,Cu6Zn3Al1, respectively. The characteristic studies of the catalysts revealed that appropriate incorporationof a minor amount of the CNTs into the CuiZnjAlk brought about little change in the apparent activationenergy of the methanol synthesis reaction, however, led to a considerable increase in the catalyst's active Cusurface area and pronouncedly enhanced the stationary-state concentration of active hydrogen-adspecieson the surface of the functioning catalyst, which would be favorable to increasing the rate of the CO hydro-genation reactions. Moreover, the operation temperature for methanol synthesis over the CNT-promotedcatalysts can be 10-20 degrees lower than that over the corresponding CNT-free contrast system, whichwould contribute considerably to an increase in equilibrium CO-conversion and CH3OH-yield.

  9. A high-performance platinum electrocatalyst loaded on a graphene hydrogel for high-rate methanol oxidation.

    Science.gov (United States)

    Wang, Xiluan; Li, Chun; Shi, Gaoquan

    2014-06-01

    Platinum (Pt)-based catalysts used in direct methanol fuel cells (DMFCs) usually suffer from low catalytic activity, slow kinetics of methanol oxidation and poor electrochemical stability. This is mainly due to the toxic effect of carbon monoxide and inefficient use of the Pt catalysts. To address these problems, we immobilized Pt nanoparticles with diameters of 4-6 nm onto the three-dimensional (3D) interpenetrating graphene networks (graphene hydrogel or G-Gel) deposited in the micropores of nickel foam (NF). In this Pt/G-Gel/NF composite catalyst, nearly all the Pt nanoparticles are accessible to methanol and can be efficiently used for electrocatalyzation. It showed excellent electrochemical stability and an activity 2.6 times that of a conventional Pt/reduced graphene oxide (Pt/rGO) composite catalyst. Furthermore, the rate of methanol electro-oxidation at the Pt/G-Gel/NF catalyst can be about 27 times that at the Pt/rGO catalyst, making it applicable for fabricating DMFCs with high current and/or power outputs.

  10. Control and experimental characterization of a methanol reformer for a 350 W high temperature polymer electrolyte membrane fuel cell system

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen; Sahlin, Simon Lennart

    2013-01-01

    This work presents a control strategy for controlling the methanol reformer temperature of a 350 W high temperature polymer electrolyte membrane fuel cell system, by using a cascade control structure for reliable system operation. The primary states affecting the methanol catalyst bed temperature...... is the water and methanol mixture fuel flow and the burner fuel/air ratio and combined flow. An experimental setup is presented capable of testing the methanol reformer used in the Serenergy H3 350 Mobile Battery Charger; a high temperature polymer electrolyte membrane (HTPEM) fuel cell system....... The experimental system consists of a fuel evaporator utilizing the high temperature waste gas from the cathode air cooled 45 cell HTPEM fuel cell stack. The fuel cells used are BASF P1000 MEAs which use phosphoric acid doped polybenzimidazole membranes. The resulting reformate gas output of the reformer system...

  11. Design and Control of High Temperature PEM Fuel Cell Systems using Methanol Reformers with Air or Liquid Heat Integration

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen; Sahlin, Simon Lennart

    2013-01-01

    The present work describes the ongoing development of high temperature PEM fuel cell systems fuelled by steam reformed methanol. Various fuel cell system solutions exist, they mainly differ depending on the desired fuel used. High temperature PEM (HTPEM) fuel cells offer the possibility of using...... methanol is converted to a hydrogen rich gas with CO2 trace amounts of CO, the increased operating temperatures allow the fuel cell to tolerate much higher CO concentrations than Nafion-based membranes. The increased tolerance to CO also enables the use of reformer systems with less hydrogen cleaning steps...... liquid fuels such as methanol, due to the increased robustness of operating at higher temperatures (160-180oC). Using liquid fuels such as methanol removes the high volume demands of compressed hydrogen storages, simplifies refueling, and enables the use of existing fuel distribution systems. The liquid...

  12. Design and Control of High Temperature PEM Fuel Cell Systems using Methanol Reformers with Air or Liquid Heat Integration

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Sahlin, Simon Lennart; Justesen, Kristian Kjær

    The present work describes the ongoing development of high temperature PEM fuel cell systems fuelled by steam reformed methanol. Various fuel cell system solutions exist, they mainly differ depending on the desired fuel used. High temperature PEM (HTPEM) fuel cells offer the possibility of using...... methanol is converted to a hydrogen rich gas with CO2 trace amounts of CO, the increased operating temperatures allow the fuel cell to tolerate much higher CO concentrations than Nafion-based membranes. The increased tolerance to CO also enables the use of reformer systems with less hydrogen cleaning steps...... liquid fuels such as methanol, due to the increased robustness of operating at higher temperatures (160-180oC). Using liquid fuels such as methanol removes the high volume demands of compressed hydrogen storages, simplifies refueling, and enables the use of existing fuel distribution systems. The liquid...

  13. Investigating the effects of methanol-water vapor mixture on a PBI-based high temperature PEM fuel cell

    DEFF Research Database (Denmark)

    Araya, Samuel Simon; Andreasen, Søren Juhl; Nielsen, Heidi Venstrup

    2012-01-01

    This paper investigates the effects of methanol and water vapor on the performance of a high temperature proton exchange membrane fuel cell (HT-PEMFC). A H3PO4-doped polybenzimidazole (PBI) membrane electrode assembly (MEA), Celtec P2100 of 45 cm2 of active surface area from BASF was employed....... A long-term durability test of around 1250 h was performed, in which the concentrations of methanol-water vapor mixture in the anode feed gas were varied. The fuel cell showed a continuous performance decay in the presence of vapor mixtures of methanol and water of 5% and 8% by volume in anode feed...

  14. Disk-outflow models as applied to high mass star forming regions through methanol and water maser observations

    CERN Document Server

    Farmer, Hontas

    2013-01-01

    As the recent publication by Breen et al (2013) found Class II methanol masers are exclusively associated with high mass star forming regions. Based on the positions of the Class I and II methanol and H$_{2}$O masers, UC H II regions and 4.5 $\\mu$m infrared sources, and the center velocities ($v_{\\text{LSR}}$) of the Class I methanol and H$_{2}$O masers, compared to the $v_{\\text{LSR}}$ of the Class II methanol masers, we propose three disk-outflow models that may be traced by methanol masers. In all three models, we have located the Class II methanol maser near the protostar, and the Class I methanol maser in the outflow, as is known from observations during the last twenty years. In our first model, the H$_{2}$O masers trace the linear extent of the outflow. In our second model, the H$_{2}$O masers are located in a circumstellar disk. In our third model, the H$_{2}$O masers are located in one or more outflows near the terminating shock where the outflow impacts the ambient interstellar medium. Together, the...

  15. Effect of trace rare earth element Er on high pure Al

    Institute of Scientific and Technical Information of China (English)

    杨军军; 聂祚仁; 金头男; 徐国富; 付静波; 阮海琼; 左铁镛

    2003-01-01

    The influence of trace Er addition on high pure aluminum was studied by mechanical properties measurement,hardness measurement, optical microscope,transmission electron microscope and energy spectrum analysis. The results show that minor Er in the studied alloy exists in the form of Al3Er,only a few of Er in α-Al based solid solution .Primary Al3Er particles formed during solidification were often found at the center of aluminum grains and acted as heterogeneous nucleus, also increased the rate of nucleation, therefore the grain are remarkably refined. Trace Er addition to high pure aluminum is able to increase the mechanical properties of high pure Al, which is caused by fine grain strengthening, substructure strengthening and precipitation strengthening. The recrystallization temperature of Er-doped aluminum increases above 50 ℃, which is caused by the pinning effect of highly dispersed fine Al3Er precipitates on dislocations and sub-grain boundaries.

  16. A calculation method of cracking moment for the high strength concrete beams under pure torsion

    Indian Academy of Sciences (India)

    Metin Husem; Ertekin Oztekin; Selim Pul

    2011-02-01

    In this study, a method is given to calculate cracking moments of high strength reinforced concrete beams under the effect of pure torsion. To determine the method, both elastic and plastic theories were used. In this method, dimensions of beam cross-section were considered besides stirrup and longitudinal reinforcements. Two plain high strength concrete (without reinforcement) and eight high strength reinforced concrete beams which have two different cross-sections (150 × 250 mm and 150 × 300 mm) were produced to examine the validity of the proposed method. The predictions of the proposed approach for the calculation of the cracking moment of beams under pure torsion were compared with the experimental and the analytical results of previous studies. From these comparisons it is concluded that the predictions of the proposed equations for the cracking moment of plain and reinforced high strength concrete beams under pure torsion are closer to the experimental data compared to the analytical results of previous theories.

  17. Thermophilic sulfate reduction and methanogenesis with methanol in a high rate anaerobic reactor

    NARCIS (Netherlands)

    Weijma, J.; Stams, A.J.M.; Hulshoff Pol, L.W.; Lettinga, G.

    2000-01-01

    Sulfate reduction outcompeted methanogenesis at 65°C and pH 7.5 in methanol and sulfate-fed expanded granular sludge bed reactors operated at hydraulic retention times (HRT) of 14 and 3.5 h, both under methanol-limiting and methanol-overloading conditions. After 100 and 50 days for the reactors

  18. High Resolution Surveys of the Water and Methanol Star Formation Masers in the Central Molecular Zone

    Science.gov (United States)

    Rickert, Matthew; Yusef-Zadeh, Farhad; Ott, Juergen; Meier, David S.; Krieger, Nico; SWAG

    2017-01-01

    We present some of the first high resolution fully interferometric surveys of 6.7 GHz methanol and 22 GHz water masers towards the Central Molecular Zone (CMZ). These masers are good signposts for early (methanol masers with resolutions of 0.9” (0.04 pc) and 0.4 km/s (8 kHz) and an average channel sensitivity of ~0.01 Jy/beam. With this high resolution and sensitivity, we have detected ~100 methanol masers, which is over a factor of two more than has previously been detected. We have also conducted two surveys of water masers in this region. As part of the Survey of Water and Ammonia in the Galactic Center (SWAG), the Australia Telescope Compact Array (ATCA) was used to survey a variety of molecular lines, including the 22 GHz water line. With the ATCA, we have detected over 200 water masers using resolutions of 26” (1 pc) and 2 km/s (60 kHz) and an average channel sensitivity of ~0.01 Jy/beam. Afterward, we conducted the first on-the-fly (OTF) VLA survey of water masers with improved resolutions of 0.7” (0.03 pc) and 0.4 km/s (26 kHz) and an average channel sensitivity of ~0.05 Jy/beam. Although the analysis of this OTF survey is not yet complete, we have already identified water masers that were not visible in the SWAG data.The improvement in the number of detected masers allows us to better analyze the distribution of these masers. We show that the SWAG water masers appear uniformly distributed along the Galactic plane, despite the asymmetry of the molecular gas distribution, where ~2/3 of the gas mass is located at positive Galactic longitudes. The methanol masers follow the molecular gas distribution, with a majority of the masers being found at positive longitudes. This could indicate a difference in the star forming history of these two parts of the CMZ and/or that the 22 GHz water masers are contaminated by water masers produced from evolved stars as well as star forming regions, indicating that a larger percentage of 22 GHz water masers are produced

  19. Hydrothermal synthesis of highly crystalline RuS{sub 2} nanoparticles as cathodic catalysts in the methanol fuel cell and hydrochloric acid electrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yanjuan [Key Laboratory of Marine Chemistry Theory and Technology, Minisry of Education Ocean University of China, Qingdao, 266100 (China); College of Material Science and Engineering, Key Laboratory of Automobile Materials of Ministry of Education, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Li, Nan, E-mail: lin@jlu.edu.cn [College of Material Science and Engineering, Key Laboratory of Automobile Materials of Ministry of Education, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Yanagisawa, Kazumichi [Research Laboratory of Hydrothermal Chemistry, Kochi University, Kochi 780-8520 (Japan); Li, Xiaotian [College of Material Science and Engineering, Key Laboratory of Automobile Materials of Ministry of Education, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Yan, Xiao [Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University, Changchun 130012 (China)

    2015-05-15

    Highlights: • Highly crystalline RuS{sub 2} nanoparticles have been first synthesized by a “one-step” hydrothermal method. • The product presents a pure cubic phase of stoichiometric ratio RuS{sub 2} with average particle size of 14.8 nm. • RuS{sub 2} nanoparticles were used as cathodic catalysts in methanol fuel cell and hydrochloric acid electrolysis. • The catalyst outperforms commercial Pt/C in methanol tolerance and stability towards Cl{sup −}. - Abstract: Highly crystalline ruthenium sulfide (RuS{sub 2}) nanoparticles have been first synthesized by a “one-step” hydrothermal method at 400 °C, using ruthenium chloride and thiourea as reactants. The products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy/energy disperse spectroscopy (SEM/EDS), thermo gravimetric-differential thermal analyze (TG-DTA), transmission electron microscopy equipped with selected area electron diffraction (TEM/SAED). Fourier transform infrared spectra (IR), and X-ray photoelectron spectroscopy (XPS). XRD result illustrates that the highly crystalline product presents a pure cubic phase of stoichiometric ratio RuS{sub 2} and the average particle size is 14.8 nm. SEM and TEM images display the products have irregular shape of 6–25 nm. XPS analyst indicates that the sulfur exists in the form of S{sub 2}{sup 2−}. Cyclic voltammetry (CV), rotating disk electrode (RDE), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) measurements are conducted to evaluate the electrocatalytic activity and stability of the highly crystalline RuS{sub 2} nanoparticles in oxygen reduction reaction (ORR) for methanol fuel cell and hydrochloric acid electrolysis. The results illustrate that RuS{sub 2} is active towards oxygen reduction reaction. Although the activity of RuS{sub 2} is lower than that of Pt/C, the RuS{sub 2} catalyst outperforms commercial Pt/C in methanol tolerance and stability towards Cl{sup −}.

  20. Comment on "Design of a broadband highly dispersive pure silica photonic crystal fiber"

    DEFF Research Database (Denmark)

    Mortensen, Niels Asger

    2008-01-01

    In a recent paper, Subbaraman et al. [Appl. Opt. 46, 3263–3268 (2007)] reported a theoretical and numerical study of highly dispersive pure silica photonic crystal fiber supporting group-velocity dispersion exceeding −2 × 104 ps=nm=km. This Comment argues that the authors consider only one of two...

  1. Stable operation of air-blowing direct methanol fuel cells with high performance

    Science.gov (United States)

    Park, Jun-Young; Lee, Jin-Hwa; Kim, Jirae; Han, Sangil; Song, Inseob

    A membrane electrode assembly (MEA) that is a combination of a catalyst-coated membrane (CCM) for the anode and a catalyst-coated substrate (CCS) for the cathode is studied under air-blower conditions for direct methanol fuel cells (DMFCs). Compared with MEAs prepared by only the CCS method, the performance of DMFC MEAs employing the combination method is significantly improved by 30% with less methanol crossover. This feature can be attributed to an enhanced electrode|membrane interface in the anode side and significantly higher catalyst efficiency. Furthermore, DMFC MEAs designed by the combination method retain high power density without any degradation, while the CCM-type cell shows a downward tendency in electrochemical performance under air-blower conditions. This may be due to MEAs with CCM have a much more difficult structure of catalytic active sites in the cathode to eliminate the water produced by electrochemical reaction. In addition, DMFCs produced via combination methods exhibit a lower water crossover flux than CCS alternatives, due to the comparatively dense structure of the CCM anode. Hence, DMFCs with a combination MEA structure demonstrate the feasibility of a small fuel cell system employing the low noise of a fan, instead of a noisy and large capacity air pump, for portable electronic devices.

  2. Methanol production method and system

    Science.gov (United States)

    Chen, Michael J.; Rathke, Jerome W.

    1984-01-01

    Ethanol is selectively produced from the reaction of methanol with carbon monoxide and hydrogen in the presence of a transition metal carbonyl catalyst. Methanol serves as a solvent and may be accompanied by a less volatile co-solvent. The solution includes the transition metal carbonyl catalysts and a basic metal salt such as an alkali metal or alkaline earth metal formate, carbonate or bicarbonate. A gas containing a high carbon monoxide to hydrogen ratio, as is present in a typical gasifer product, is contacted with the solution for the preferential production of ethanol with minimal water as a byproduct. Fractionation of the reaction solution provides substantially pure ethanol product and allows return of the catalysts for reuse.

  3. Experimental and Kinetic Modeling Study of Methanol Ignition and Oxidation at High Pressure

    DEFF Research Database (Denmark)

    Aranda, V.; Christensen, J. M.; Alzueta, Maria

    2013-01-01

    A detailed chemical kinetic model for oxidation of CH3OH at high pressure and intermediate temperatures has been developed and validated experimentally. Ab initio calculations and Rice–Ramsperger–Kassel–Marcus/transition state theory (RRKM/TST) analysis were used to obtain rate coefficients for CH...... the conditions studied, the onset temperature for methanol oxidation was not dependent on the stoichiometry, whereas increasing pressure shifted the ignition temperature toward lower values. Model predictions of the present experimental results, as well as rapid compression machine data from the literature, were...... and lower pressures. At the high pressures, the modeling predictions for onset of reaction were particularly sensitive to the CH 3 OH + HO 2⇌ CH 2 OH +H2O2reaction....

  4. High Pressure Equation of State Studies Using Ethanol-Methanol And Argon As Pressure Medium

    Science.gov (United States)

    Godwal, B. K.; Speziale, S.; Clark, S.; Yan, J.; Jeanloz, R.

    2008-12-01

    Experimental high pressure studies are extremely important to planetary science, material science and to the development of condensed matter theory. With experimental difficulties in creating the extreme pressure temperature conditions appropriate to planetary interiors, the approach used is to obtain the thermodynamic data on materials of interest by extrapolating the condensed matter theory which has been benchmarked with the outcome of high pressure experiments to the available high pressures. However the high pressure data used to match the theory heavily depends on the use of pressure media; like ethanol-methanol, silicon oil, argon and helium. Unfortunately still there exist controversy in the literature even with the use of helium as pressure medium as illustrated by the unsettled debate on Zn and Os among different groups. We have measured the equation of state of intermetallic compound AuIn2 and Cd0.8Hg0.2 alloy using ethanol-methanol and argon to the pressure of 20 GPa to confirm the appearance of anomalies in the data due to occurrence of subtle electronic phase transitions. However these anomalies can also be attributed to oriented lattice strains and local non-hydrostatic conditions. We have tried to remove these at room temperature by stabilizing the sample in argon medium in the diamond anvil cell with proper annealing as indicated by the uniformity of the pressure across the sample by ruby fluorescence measurements. We will present the data revealing the electronic transition in AuIn2 at 2.7 GPa and in Cd0.8Hg0.2 near 9 and 18 GPa.

  5. High methanol oxidation activity of well-dispersed pt nanoparticles on carbon nanotubes using nitrogen doping.

    Science.gov (United States)

    Fang, Wei-Chuan

    2009-10-09

    Pt nanoparticles (NPs) with the average size of 3.14 nm well dispersed on N-doped carbon nanotubes (CNTs) without any pretreatment have been demonstrated. Structural properties show the characteristic N bonding within CNTs, which provide the good support for uniform distribution of Pt NPs. In electrochemical characteristics, N-doped CNTs covered with Pt NPs show superior current density due to the fact that the so-called N incorporation could give rise to the formation of preferential sites within CNTs accompanied by the low interfacial energy for immobilizing Pt NPs. Therefore, the substantially enhanced methanol oxidation activity performed by N-incorporation technique is highly promising in energy-generation applications.

  6. High Methanol Oxidation Activity of Well-Dispersed Pt Nanoparticles on Carbon Nanotubes Using Nitrogen Doping

    Directory of Open Access Journals (Sweden)

    Fang Wei-Chuan

    2009-01-01

    Full Text Available Abstract Pt nanoparticles (NPs with the average size of 3.14 nm well dispersed on N-doped carbon nanotubes (CNTs without any pretreatment have been demonstrated. Structural properties show the characteristic N bonding within CNTs, which provide the good support for uniform distribution of Pt NPs. In electrochemical characteristics, N-doped CNTs covered with Pt NPs show superior current density due to the fact that the so-called N incorporation could give rise to the formation of preferential sites within CNTs accompanied by the low interfacial energy for immobilizing Pt NPs. Therefore, the substantially enhanced methanol oxidation activity performed by N-incorporation technique is highly promising in energy-generation applications.

  7. Integration of high temperature PEM fuel cells with a methanol reformer

    DEFF Research Database (Denmark)

    Pan, Chao; He, Ronghuan; Li, Qingfeng

    2005-01-01

    On-board generation of hydrogen by methanol reforming is an efficient and practical option to fuel PEMFC especially for vehicle propulsion purpose. The methanol reforming can take place at temperatures around 200°C with a nearly 100% conversion at a hydrogen yield of about 400 L–(h–kg catalyst)-1...

  8. Investigation on grain size effect in high strain rate ductility of 1100 pure aluminum

    Science.gov (United States)

    Bonora, N.; Bourne, N.; Ruggiero, A.; Iannitti, G.; Testa, G.

    2017-01-01

    The effect of the initial grain size on the material ductility at high strain rates in 1100 pure aluminum was investigated. Dynamic tensile extrusion (DTE) tests, at different impact velocities, were performed. Samples have been annealed at 350°C for different exposure times to induce grain growth. Extruded fragments were soft-recovered and the overall length of the extruded jets was used as a measure of material ductility at high strain rates. Numerical simulation of DTE test at different velocity was performed using the modified Rusinek-Klepaczko constitutive model. Results indicates that, as reported for pure copper, the overall ductility of the aluminum increases when grain size decreases. Numerical simulation results were in quite good agreement with experimental data.

  9. Fuel Characteristics of Biodiesel Produced from a High-Acid Oil from Soybean Soapstock by Supercritical-Methanol Transesterification

    Directory of Open Access Journals (Sweden)

    Yi-Wei Lin

    2012-07-01

    Full Text Available A supercritical methanol transesterification method was applied to produce biodiesel from the high-acid oil of soybean soapstock. The fuel properties of biodiesel produced with various molar ratios of methanol to raw oil were analyzed and compared in this experimental study. Oleic acid (C18:1, linoleic acid (C18:2, and palmitic acid (C16:0 were the three main compounds in the high-acid oil-biodiesel. The saturated fatty acid content of the high-acid oil increased significantly due to the supercritical-methanol transesterification reaction. The fuel characteristics of the resulting high-acid oil, including the specific gravity and kinematic viscosity, were also greatly improved. The saturated fatty acid content of the biodiesel produced from the high-acid oil was higher than that of biodiesel from waste cooking oil produced by the subcritical transesterification using a strongly alkaline catalyst. The high-acid oil-biodiesel that was produced with a molar ratio of methanol to raw oil of 42 had the best fuel properties, including a higher distillation temperature and cetane index and a lower kinematic viscosity and water content, among the biodiesels with different molar ratios.

  10. Nanoporous PdZr surface alloy as highly active non-platinum electrocatalyst toward oxygen reduction reaction with unique structure stability and methanol-tolerance

    Science.gov (United States)

    Duan, Huimei; Xu, Caixia

    2016-06-01

    Nanoporous (NP) PdZr alloy with controllable bimetallic ratio is successfully fabricated by a simple dealloying method. By leaching out the more reactive Al from PdZrAl precursor alloy, NP-PdZr alloy with smaller ligament size was generated, characterized by the nanoscaled interconnected network skeleton and hollow channels extending in all three dimensions. Upon voltammetric scan in acid solution, the dissolution of surface Zr atoms generates the highly active Pd-Zr surface alloy with a nearly pure Pd surface and Pd-Zr alloy core. The NP-Pd80Zr20 surface alloy exhibits markedly enhanced specific and mass activities as well as higher catalytic stability toward oxygen reduction reaction (ORR) compared with NP-Pd and the state-of-the-art Pt/C catalysts. In addition, the NP-Pd80Zr20 surface alloy shows a better selectivity for ORR than methanol in the 0.1 M HClO4 and 0.1 M methanol mixed solution. X-ray photoelectron spectroscopy and density functional theory calculations both demonstrate that the weakened Pd-O bond and improved ORR performances in turn depend on the downshifted d-band center of Pd due to the alloying Pd with Zr (20 at.%). The as-made NP-PdZr alloy holds prospective applications as a cathode electrocatalyst in fuel-cell-related technologies with the advantages of superior overall ORR performances, unique structure stability, and easy preparation.

  11. Influence of the high pressure torsion die geometry on the allotropic phase transformations in pure Zr

    Energy Technology Data Exchange (ETDEWEB)

    Zhilyaev, A.P. [Centro Nacional de Investigaciones Metalurgicas (CENIM), CSIC, 28040 Madrid (Spain); Institute for Metals Superplasticity Problems, RAS, 450001 Ufa (Russian Federation); Galvez, F. [ETS Ingenieros de Caminos, Universidad Politecnica de Madrid, 28040 Madrid (Spain); Sharafutdinov, A. [Innovation Scientific Technology Center ' Iskra' , 450000 Ufa (Russian Federation); Perez-Prado, M.T., E-mail: teresa.perez.prado@imdea.org [Madrid Institute for Advanced Studies of Materials (IMDEA-Materials), C/Profesor Aranguren s/n, 28040 Madrid (Spain)

    2010-06-25

    The effect of the press geometry in the {alpha} to {omega} + {beta} transformation in pure Zr by high pressure torsion (HPT) was investigated. Specimens were processed in constrained and unconstrained setups using a wide range of applied pressures and 5 anvil turns. The resulting microstructures were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM and HRTEM) and electron backscatter diffraction (EBSD). Microhardness distributions were measured for each condition. The transformation kinetics and the stability of the fabricated nanostructures are enhanced when using an unconstrained setup. In the samples processed by constrained HPT the full transformation does not take place even at the highest pressures applied. Additionally, post-processing room temperature grain growth of some of the remaining nanocrystalline {alpha}-Zr grains with (0 0 0 1) orientations occurs, leading to a significant decrease in hardness. HRTEM allowed confirming the presence of pure {beta}-Zr.

  12. High-performance hybrid oxide catalyst of manganese and cobalt for low-pressure methanol synthesis

    National Research Council Canada - National Science Library

    Li, Cheng-Shiuan; Melaet, Gérôme; Ralston, Walter T; An, Kwangjin; Brooks, Christopher; Ye, Yifan; Liu, Yi-Sheng; Zhu, Junfa; Guo, Jinghua; Alayoglu, Selim; Somorjai, Gabor A

    2015-01-01

    ... in the scanning transmission electron microscopy mode. Through control experiments, we find that the catalyst's chemical nature and architecture are the key factors in enabling the enhanced methanol synthesis and ethylene production...

  13. Fabrication of Highly Stable and Efficient PtCu Alloy Nanoparticles on Highly Porous Carbon for Direct Methanol Fuel Cells.

    Science.gov (United States)

    Khan, Inayat Ali; Qian, Yuhong; Badshah, Amin; Zhao, Dan; Nadeem, Muhammad Arif

    2016-08-17

    Boosting the durability of Pt nanoparticles by controlling the composition and morphology is extremely important for fuel cells commercialization. We deposit the Pt-Cu alloy nanoparticles over high surface area carbon in different metallic molar ratios and optimize the conditions to achieve desired material. The novel bimetallic electro-catalyst {Pt-Cu/PC-950 (15:15%)} offers exceptional electrocatalytic activity when tested for both oxygen reduction reaction and methanol oxidation reactions. A high mass activity of 0.043 mA/μgPt (based on Pt mass) is recorded for ORR. An outstanding longevity of this electro-catalyst is noticed when compared to 20 wt % Pt loaded either on PC-950 or commercial carbon. The high surface area carbon support offers enhanced activity and prevents the nanoparticles from agglomeration, migration, and dissolution as evident by TEM analysis.

  14. High throughput evaluation of perovskite-based anode catalysts for direct methanol fuel cells

    Science.gov (United States)

    Deshpande, Kishori; Mukasyan, Alexander; Varma, Arvind

    Liquid feed direct methanol fuel cells (DMFC) are promising candidates for portable power applications. However, owing to the problems associated with expensive Pt-based catalysts, viz., CO poisoning, a promising approach is to use complex oxides of the type ABO 3 (A = Sr, Ce, La, etc. and B = Co, Fe, Ni, Pt, Ru, etc.). In the current work, a variety of ABO 3 and A 2BO 4 type non-noble and partially substituted noble metal high surface area compounds were synthesized by an effective and rapid aqueous combustion synthesis (CS). Their catalytic activity was evaluated by using "High Throughput Screening Unit"-NuVant System, which compares up to 25 compositions simultaneously under DMFC conditions. It was found that the Sr-based perovskites showed performance comparable with the standard Pt-Ru catalyst. Further, it was observed that the method of doping SrRuO 3 with Pt influenced the activity. Specifically, platinum added during aqueous CS yielded better catalyst than when added externally at the ink preparation stage. Finally, it was also demonstrated that the presence of SrRuO 3 significantly enhanced the catalytic properties of Pt, leading to superior performance even at lower noble metal loadings.

  15. Phase equilibrium data and thermodynamic modelling of the system (propane + DMF + methanol) at high pressures

    Energy Technology Data Exchange (ETDEWEB)

    Charin, Rafael M. [Department of Chemical Engineering, Federal University of Parana (UFPR), Polytechnic Center (DTQ/ST/UFPR), Jardim das Americas, Curitiba 82530-990, PR (Brazil); Department of Food Engineering, URI - Campus de Erechim, Av. Sete de Setembro, 1621, Erechim 99700-000, RS (Brazil); Corazza, Marcos L.; Ndiaye, Papa M. [Department of Chemical Engineering, Federal University of Parana (UFPR), Polytechnic Center (DTQ/ST/UFPR), Jardim das Americas, Curitiba 82530-990, PR (Brazil); Rigo, Aline A.; Mazutti, Marcio A. [Department of Food Engineering, URI - Campus de Erechim, Av. Sete de Setembro, 1621, Erechim 99700-000, RS (Brazil); Vladimir Oliveira, J., E-mail: vladimir@uricer.edu.b [Department of Food Engineering, URI - Campus de Erechim, Av. Sete de Setembro, 1621, Erechim 99700-000, RS (Brazil)

    2011-03-15

    Reported in this work are phase equilibrium data at high pressures for the binary and ternary systems formed by {l_brace}propane + N,N-dimethylformamide (DMF) + methanol{r_brace}. Phase equilibrium measurements were performed in a high-pressure, variable-volume view cell, following the static synthetic method for obtaining the experimental bubble and dew points transition data over the temperature range of (363 to 393) K, pressures up to 11.5 MPa and overall mole fraction of the lighter component varying from 0.1 to 0.995. For the systems investigated, vapour-liquid (VLE), liquid-liquid (LLE) and vapour-liquid-liquid (VLLE) phase transitions were visually recorded. Results show that the systems investigated present UCST (upper critical solution temperature) phase transition curves with an UCEP (upper critical end point) at a temperature higher than the propane critical temperature. The experimental data were modelled using the Peng-Robinson equation of state with the Wong-Sandler and the classical quadratic mixing rules, affording a satisfactory representation of the experimental data.

  16. Phase equilibrium data and thermodynamic modeling of the system (CO{sub 2} + biodiesel + methanol) at high pressures

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Leandro F.; Segalen da Silva, Diogo Italo [Department of Chemical Engineering, Federal University of Parana, CEP 81531-990, Curitiba, PR (Brazil); Rosa da Silva, Fabiano; Ramos, Luiz P. [Department of Chemistry, Federal University of Parana, CEP 81531-990, Curitiba, PR (Brazil); Ndiaye, Papa M. [Department of Chemical Engineering, Federal University of Parana, CEP 81531-990, Curitiba, PR (Brazil); Corazza, Marcos L., E-mail: corazza@ufpr.br [Department of Chemical Engineering, Federal University of Parana, CEP 81531-990, Curitiba, PR (Brazil)

    2012-01-15

    Highlights: > We measured phase behavior for the system involving {l_brace}CO{sub 2} + biodiesel + methanol{r_brace}. > The saturation pressures were obtained using a variable-volume view cell. > The experimental data were modeled using PR-vdW2 and PR-WS equations of state. - Abstract: The main objective of this work was to investigate the high pressure phase behavior of the binary systems {l_brace}CO{sub 2}(1) + methanol(2){r_brace} and {l_brace}CO{sub 2}(1) + soybean methyl esters (biodiesel)(2){r_brace} and the ternary system {l_brace}CO{sub 2}(1) + biodiesel(2) + methanol(3){r_brace} were determined. Biodiesel was produced from soybean oil, purified, characterized and used in this work. The static synthetic method, using a variable-volume view cell, was employed to obtain the experimental data in the temperature range of (303.15 to 343.15) K and pressures up to 21 MPa. The mole fractions of carbon dioxide were varied according to the systems as follows: (0.2383 to 0.8666) for the binary system {l_brace}CO{sub 2}(1) + methanol(2){r_brace}; (0.4201 to 0.9931) for the binary system {l_brace}CO{sub 2}(1) + biodiesel(2){r_brace}; (0.4864 to 0.9767) for the ternary system {l_brace}CO{sub 2}(1) + biodiesel(2) + methanol(3){r_brace} with a biodiesel to methanol molar ratio of (1:3); and (0.3732 to 0.9630) for the system {l_brace}CO{sub 2} + biodiesel + methanol{r_brace} with a biodiesel to methanol molar ratio of (8:1). For these systems, (vapor + liquid), (liquid + liquid), (vapor + liquid + liquid) transitions were observed. The phase equilibrium data obtained for the systems were modeled using the Peng-Robinson equation of state with the classical van der Waals (PR-vdW2) and Wong-Sandler (PR-WS) mixing rules. Both thermodynamic models were able to satisfactorily correlate the phase behavior of the systems investigated and the PR-WS presented the best performance.

  17. Synthesis of highly active and dual-functional electrocatalysts for methanol oxidation and oxygen reduction reactions

    Science.gov (United States)

    Zhao, Qi; Zhang, Geng; Xu, Guangran; Li, Yingjun; Liu, Baocang; Gong, Xia; Zheng, Dafang; Zhang, Jun; Wang, Qin

    2016-12-01

    The promising Pt-based ternary catalyst is crucial for polymer electrolyte membrane fuel cells (PEMFCs) due to improving catalytic activity and durability for both methanol oxidation reaction and oxygen reduction reaction. In this work, a facile strategy is used for the synthesis ternary RuMPt (M = Fe, Co, Ni, and Cu) nanodendrities catalysts. The ternary RuMPt alloys exhibit enhanced specific and mass activity, positive half-wave potential, and long-term stability, compared with binary Pt-based alloy and the commercial Pt/C catalyst, which is attributed to the high electron density and upshifting of the d-band center for Pt atoms, and synergistic catalytic effects among Pt, M, and Ru atoms by introducing a transition metal. Impressively, the ternary RuCoPt catalyst exhibits superior mass activity (801.59 mA mg-1) and positive half-wave potential (0.857 V vs. RHE) towards MOR and ORR, respectively. Thus, the RuMPt nanocomposite is a very promising material to be used as dual electrocatalyst in the application of PEMFCs.

  18. The high performance of tungsten carbides/porous bamboo charcoals supported Pt catalysts for methanol electrooxidation

    Science.gov (United States)

    Ma, Chun-an; Xu, Chenbin; Shi, Meiqin; Song, Guanghui; Lang, Xiaoling

    2013-11-01

    In this paper, a kind of environmental friendly and cost-effective bamboo charcoal (BC) is used as catalyst support in DMFCs instead of carbon nanotubes (CNTs), which is toxic and expensive. After special treatments, we obtain a sponge-like three-dimensional (3D) BC, which can provide high specific surface area (1264.5 m2 g-1) and porous matrices. Then, tungsten carbide (WC) and Pt are loaded on the BCs with microwave-assisted technique and 3D structural Pt/WC/BCs electro-catalyst is finally fabricated. Subsequently, the catalyst is characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In the further electrochemical investigation, it was found that Pt/WC/BCs catalyst has higher performance (2.76 mA cm-2) and better CO-tolerance for methanol oxidation compared with Pt/WC/CNTs and commercial Pt/C. Herein, we believe that the as-synthesized 3D Pt/WC/BCs catalyst has great promising application in DMFCs.

  19. Route toward high-speed nano-magnonics provided by pure spin currents

    Science.gov (United States)

    Divinskiy, B.; Demidov, V. E.; Demokritov, S. O.; Rinkevich, A. B.; Urazhdin, S.

    2016-12-01

    We study experimentally the possibility to utilize pulses of pure spin current, produced via the nonlocal spin injection mechanism, to generate short packets of spin waves propagating in nanoscale magnetic waveguides. Spatially and time-resolved micro-focus Brillouin light scattering spectroscopy measurements demonstrate that the excitation by spin current results in extremely fast transient response, enabling efficient generation of short spin-wave packets with duration down to a few nanoseconds. The proposed method opens a route for the implementation of high-speed magnonic systems for transmission and processing of information on the nanoscale.

  20. A New Expression for the Full Energy Peak Efficiency of a High Pure Germanium Detector

    CERN Document Server

    Medhat, M E; Awaad, Z

    2001-01-01

    An empirical expression for the full energy photo-peak efficiency in terms of gamma-ray energy (E) and the vertical distance from the detector surface (d) (i.e. efficiency = function (d,E)) has been obtained for a high pure germanium detector (HPGe) using different standard sources. Comparison of the calculated efficiencies and the experimentally measured values for the energy range from 59.5-1332.2 keV and a source-to-detector distance of 5-30 cm showed that the theoretical values agree with the experiment.

  1. High Proton Conducting SPEEK/SiO2/PWA Composite Membranes for Direct Methanol Fuel Cells

    Institute of Scientific and Technical Information of China (English)

    ZHANG Gaowen; JIANG Jiuxin; LIU Jianing

    2011-01-01

    Sulfonated polyether ether ketone (SPEEK) based composite membranes for direct methanol fuel cell (DMFC) application were prepared by sol-gel reaction of tetraethoxysilane (TEOS) in the SPEEK matrix and the incorporation of phosphotungstic acid (PWA). The conductivity of the developed membranes was determined by impedance spectroscopy and the methanol permeability through the membranes was obtained from diffuseness experiments. The SEM images show that the addition of SiO2 and the covalent cross-linking structure lead to fine PWA particles and more uniformly dispersion. The swelling of composite membranes remains in the range of 5%-8% at 30-90 ℃ and the effusion of PWA reduces significantly. The composite membranes show a good balance in higher proton conductivity and lower methanol permeation. The cell with composite membrane has higher open circuit voltage(0.728 V) and higher peak power density(45 mW/cm2) than that with Nation 117.

  2. Facile synthesis of a mechanically robust and highly porous NiO film with excellent electrocatalytic activity towards methanol oxidation

    Science.gov (United States)

    Wang, Luoyuan; Zhang, Guoge; Liu, Yan; Li, Wenfang; Lu, Wei; Huang, Haitao

    2016-05-01

    Considerable research is being conducted in searching for effective anode catalysts in alkaline direct methanol fuel cells (DMFCs). Although significant progress has been achieved, it is still challenging to prepare non-Pt catalysts with both excellent activity and good durability. Herein, a highly porous NiO film is developed by a facile and fast anodization approach. The anodic NiO film demonstrates a high surface area, large mesopore volume and small crystallite size, leading to facilitated adsorption of reaction species, easy electrolyte penetration and fast reaction kinetics. Furthermore, as anodic NiO is grown in situ on a metallic substrate with strong adhesion strength and good electrical contact, it can be used directly as an anode catalyst for methanol oxidation without the need to add any binder or conducting agent. Such an additive-free approach greatly expedites the catalyst preparation process. The anodic NiO shows lower methanol oxidation potential, higher oxidation current and better catalytic durability than most of the state-of-the-art Ni-based catalysts reported elsewhere. As anodization is a simple, low cost and easily scaled up method, the work described here provides an exciting direction to speed up the practical application of alkaline DMFCs.Considerable research is being conducted in searching for effective anode catalysts in alkaline direct methanol fuel cells (DMFCs). Although significant progress has been achieved, it is still challenging to prepare non-Pt catalysts with both excellent activity and good durability. Herein, a highly porous NiO film is developed by a facile and fast anodization approach. The anodic NiO film demonstrates a high surface area, large mesopore volume and small crystallite size, leading to facilitated adsorption of reaction species, easy electrolyte penetration and fast reaction kinetics. Furthermore, as anodic NiO is grown in situ on a metallic substrate with strong adhesion strength and good electrical contact

  3. Characteristics of self-alkalization in high-rate denitrifying automatic circulation (DAC) reactor fed with methanol and sodium acetate.

    Science.gov (United States)

    Li, Wei; Zheng, Ping; Guo, Jun; Ji, Junyuan; Zhang, Meng; Zhang, Zonghe; Zhan, Enchao; Abbas, Ghulam

    2014-02-01

    Denitrification is a self-alkalization process. In this experiment, the characteristics of self-alkalization in high-rate heterotrophic denitrifying automatic circulation (DAC) reactor fed with methanol and sodium acetate were investigated, respectively. The results showed that, (1) The self-alkalization of high-rate denitrifying reactors was remarkably strong both with methanol and sodium acetate as carbon sources, while the effluent pH was much lower than the stoichiometric values and the malfunction from self-alkalization of denitrification was far less serious than expected. (2) The self-adaptation of the reactors was attributed to the neutralization of carbon dioxide (oxidization product of organic matter) and the self-adaptation of denitrifying sludge. The formation and discharge of calcium carbonate precipitates gave rise to lower effluent pH and alkalinity than the stoichiometric values.

  4. Highly efficient anode catalyst with a Ni@PdPt core–shell nanostructure for methanol electrooxidation in alkaline media

    Institute of Scientific and Technical Information of China (English)

    Pei-shu Yu; Chun-tao Liu; Bo Feng; Jia-feng Wan; Li Li; Chun-yu Du

    2015-01-01

    To enhance the electrocatalytic activity of anode catalysts used in alkaline-media direct methanol fuel cells (DMFCs), a Ni@PdPt electrocatalyst was successfully prepared using a three-phase-transfer method. The Ni@PdPt electrocatalyst was characterized by X-ray dif-fraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and high-resolution TEM (HRTEM) techniques. The experimental results indicate that the average particle size of the core–shell-structured Ni@PdPt electrocatalyst is approxi-mately 5.6 nm. The Ni@PdPt electrocatalyst exhibits a catalytic activity 3.36 times greater than that of PdPt alloys for methanol oxidation in alkaline media. The developed Ni@PdPt electrocatalyst offers a promising alternative as a highly electrocatalytically active anode catalyst for alkaline DMFCs.

  5. Allotropic phase transformation of pure zirconium by high-pressure torsion

    Energy Technology Data Exchange (ETDEWEB)

    Edalati, Kaveh, E-mail: kaveh.edalati@zaiko6.zaiko.kyushu-u.ac.jp [Department of Materials Science and Engineering, Faculty of Engineering, Kyushu University, Fukuoka 819-0395 (Japan); Horita, Zenji [Department of Materials Science and Engineering, Faculty of Engineering, Kyushu University, Fukuoka 819-0395 (Japan); Yagi, Shunsuke; Matsubara, Eiichiro [Department of Materials Science and Engineering, Faculty of Engineering, Kyoto University, Kyoto 606-8501 (Japan)

    2009-10-15

    Pure Zr is processed by high-pressure torsion (HPT) at pressures in the range of 1-40 GPa. A phase transformation occurs from {alpha} to {omega} phase during HPT at pressures above {approx}4 GPa while the total fraction of {omega} phase increases with straining and saturates to a constant level at higher strain. This phase transformation leads to microstructural refinement, hardness and strength enhancement and ductility reduction. Lattice parameter measurements confirm that c for {alpha} phase is expanded about 0.6% by the presence of {omega} phase. The temperature for reverse transformation from {omega} to {alpha} phase increases with straining and thus, straining under high pressure increases thermal stability of {omega} phase. The {omega} phase obtained by HPT is stable for more than 400 days at room temperature.

  6. Pure Cs4PbBr6: Highly Luminescent Zero-Dimensional Perovskite Solids

    KAUST Repository

    Saidaminov, Makhsud I.

    2016-09-26

    So-called zero-dimensional perovskites, such as Cs4PbBr6, promise outstanding emissive properties. However, Cs4PbBr6 is mostly prepared by melting of precursors that usually leads to a coformation of undesired phases. Here, we report a simple low-temperature solution-processed synthesis of pure Cs4PbBr6 with remarkable emission properties. We found that pure Cs4PbBr6 in solid form exhibits a 45% photoluminescence quantum yield (PLQY), in contrast to its three-dimensional counterpart, CsPbBr3, which exhibits more than 2 orders of magnitude lower PLQY. Such a PLQY of Cs4PbBr6 is significantly higher than that of other solid forms of lower-dimensional metal halide perovskite derivatives and perovskite nanocrystals. We attribute this dramatic increase in PL to the high exciton binding energy, which we estimate to be ∼353 meV, likely induced by the unique Bergerhoff–Schmitz–Dumont-type crystal structure of Cs4PbBr6, in which metal-halide-comprised octahedra are spatially confined. Our findings bring this class of perovskite derivatives to the forefront of color-converting and light-emitting applications.

  7. Role of nickel in high rate methanol degradation in anaerobic granular sludge bioreactors

    NARCIS (Netherlands)

    Fermoso, F.G.; Collins, G.; Bartacek, J.; O'Flaherty, V.; Lens, P.N.L.

    2008-01-01

    The effect of nickel deprivation from the influent of a mesophilic (30 degrees C) methanol fed upflow anaerobic sludge bed (UASB) reactor was investigated by coupling the reactor performance to the evolution of the Methanosarcina population of the bioreactor sludge. The reactor was operated at pH 7.

  8. Method for the synthesis of highly pure vaccines using the lipid core peptide system.

    Science.gov (United States)

    Moyle, Peter M; Olive, Colleen; Good, Michael F; Toth, Istvan

    2006-12-01

    Traditional vaccines consisting of whole attenuated microorganisms, killed microorganisms, or microbial components, administered with an adjuvant (e.g. alum), have been proved to be extremely successful. However, to develop new vaccines, or to improve upon current vaccines, new vaccine development techniques are required. Peptide vaccines offer the capacity to administer only the minimal microbial components necessary to elicit appropriate immune responses, minimizing the risk of vaccination associated adverse effects, and focusing the immune response toward important antigens. Peptide vaccines, however, are generally poorly immunogenic, necessitating administration with powerful, and potentially toxic adjuvants. The attachment of lipids to peptide antigens has been demonstrated as a potentially safe method for adjuvanting peptide epitopes. The lipid core peptide (LCP) system, which incorporates a lipidic adjuvant, carrier, and peptide epitopes into a single molecular entity, has been demonstrated to boost immunogenicity of attached peptide epitopes without the need for additional adjuvants. The synthesis of LCP systems normally yields a product that cannot be purified to homogeneity. The current study describes the development of methods for the synthesis of highly pure LCP analogs using native chemical ligation. Because of the highly lipophilic nature of the LCP lipid adjuvant, difficulties (e.g. poor solubility) were experienced with the ligation reactions. The addition of organic solvents to the ligation buffer solubilized lipidic species, but did not result in successful ligation reactions. In comparison, the addition of approximately 1% (w/v) sodium dodecyl sulfate (SDS) proved successful, enabling the synthesis of two highly pure, tri-epitopic Streptococcus pyogenes LCP analogs. Subcutaneous immunization of B10.BR (H-2(k)) mice with one of these vaccines, without the addition of any adjuvant, elicited high levels of systemic IgG antibodies against each of

  9. Consumption of both low and high (-)-epicatechin apple puree attenuates platelet reactivity and increases plasma concentrations of nitric oxide metabolites: A randomized controlled trial

    NARCIS (Netherlands)

    Gasper, A.; Hollands, W.; Casgrain, A.; Saha, S.; Teucher, B.; Dainty, J.R.; Venema, D.P.; Hollman, P.C.H.

    2014-01-01

    We hypothesised that consumption of flavanol-containing apple puree would modulate platelet activity and increase nitric oxide metabolite status, and that high flavanol apple puree would exert a greater effect than low flavanol apple puree. 25 subjects consumed 230 g of apple puree containing 25 and

  10. Consumption of both low and high (-)-epicatechin apple puree attenuates platelet reactivity and increases plasma concentrations of nitric oxide metabolites: A randomized controlled trial

    NARCIS (Netherlands)

    Gasper, A.; Hollands, W.; Casgrain, A.; Saha, S.; Teucher, B.; Dainty, J.R.; Venema, D.P.; Hollman, P.C.H.

    2014-01-01

    We hypothesised that consumption of flavanol-containing apple puree would modulate platelet activity and increase nitric oxide metabolite status, and that high flavanol apple puree would exert a greater effect than low flavanol apple puree. 25 subjects consumed 230 g of apple puree containing 25 and

  11. Thermal Stability of Surface Layer Microstructures of Commercially Pure Titanium Treated by High Energy Shot Peening

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yu-juan; CHEN Chun-huan; REN Rui-ming

    2004-01-01

    Commercially pure titanium was treated by high energy shot peening, and annealed at a series of temperatures. The surface layers are characterized by means of scan electronic microscope, X-Ray diffraction, transmission electronic microscope and micro-hardness testing machine. The results showed that microhardness of surface layers decreases with anneal temperature, the tendency of microhardness is similar to unannealed one, in other words, the more close to the surface, the more rapidly the hardness decreases, after reaches the depth of 50 μm, the decrease becomes steadily. But the sub-surface microhardness decreased suddenly over 500 ℃, From 550 ℃ to 650 ℃, the microhardness of surface layers almost unchanged.Observing by TEM and SEM, the grain sizes of pure titanium surface layers have increased below 500 ℃; Deformation twins begin disappearing obviously at 550 ℃; The nano-scaled grains within about 10 micrometers from surface existed even at 550℃.Surface nanocrystallization is well known as one of important methods to improve surface properties. The thermal stability of nanocrystalline microstructures was related to their preparation and application. The commercial pure Ti thermal stability of nanocrystalline and deformed microstructures induced by high-energy-shot-peening (HESP) technique was investigated. The nanostructured surface and deformed sub-surface layers of specimens were prepared through HESP treatment. The thermal stability was characterized through XRD analyses of surface layers, SEM and TEM microstructure observation and microhardness measurement of specimens annealed in different temperature in the air after HESP treatments. The results showed that after HESP treatment, the microhardness of surface layers increased with treatment time, especially in the rang of about 40 micrometers from the surface, the microhardness increase was obvious. The surface microhardness decreased gradually with annealing temperature, but the sub

  12. Highly dispersed Pt-Ni nanoparticles on nitrogen-doped carbon nanotubes for application in direct methanol fuel cells.

    Science.gov (United States)

    Jiang, Shujuan; Ma, Yanwen; Tao, Haisheng; Jian, Guoqiang; Wang, Xizhang; Fan, Yining; Zhu, Jianmin; Hu, Zheng

    2010-06-01

    Binary Pt-Ni alloyed nanoparticles supported on nitrogen-doped carbon nanotubes (NCNTs) have been facilely constructed without pre-modification by making use of the active sites in NCNTs due to the N-participation. So-obtained binary Pt-Ni alloyed nanoparticles have been highly dispersed on the outer surface of the support with the size of about 3-4 nm. The electrochemical properties of the catalysts for methanol oxidation have been systematically evaluated. Binary Pt-Ni alloyed composites with molar ratio (Pt:Ni) of 3:2 and 3:1 present enhanced electrocatalytic activities and improved tolerance to CO poisoning as well as the similar stability, in comparison with the commercial Pt/C catalyst and the monometallic Pt/NCNTs catalysts. These results imply that so-constructed nanocomposite catalysts have the potential for applications in direct methanol fuel cells.

  13. Effect of Temperature on the Void Growth in Pure Aluminium at High Strain-Rate Loading

    Institute of Scientific and Technical Information of China (English)

    QI Mei-Lan; HE Hong-Liang; YAN Shi-Lin

    2007-01-01

    @@ With the environment temperature varying from 273K to 773K, the dynamic process of void growth in pure aluminium at high strain-rate loading is calculated based on the dynamic growth equation of a void with internal pressure. The result shows that the effect of temperature on the growth of void should be emphasized. Because the initial pressure of void with gas will increase and the viscosity of materials will decrease with the rising of temperature, the growth of void is accelerated. Furthermore, material inertia restrains the growth of void evidently when the diameter exceeds 10μm. The effect of surface tension is very weak in the whole process of void growth.

  14. Influence of Trace Oxygen on the Mechanical Properties of High Pure Silver during Natural Aging

    Institute of Scientific and Technical Information of China (English)

    XIE Hongchao; ZHUANG Dianxiang; LI Ji; CHEN Liangwei; YANG Anheng; LUO Yanbo; ZHU Yong

    2012-01-01

    Two kinds of high pure silver materials with 5.3 ppm oxygen and 32.7 ppm oxygen were prepared by various melting processes,both samples were subjected to accumulative rolling with 95% thickness reduction.Their mechanical properties were tested during long natural aging.Results showed that the Ag sheet with 5.3 ppm oxygen is at full annealed state when natural aging 58 days or kept at 150℃ for 30 minutes,and the Ag sheet with 32.7 ppm oxygen is a little of recovery when natural aging a year.It is suggested that appropriate oxygen interstitial solute in Ag solid solution and a few of Ag2O particles at Ag grain boundaries impede the recovery and recrystallization of Ag sheets.

  15. Highly stable ionic-covalent cross-linked sulfonated poly(ether ether ketone) for direct methanol fuel cells

    Science.gov (United States)

    Lei, Linfeng; Zhu, Xingye; Xu, Jianfeng; Qian, Huidong; Zou, Zhiqing; Yang, Hui

    2017-05-01

    A novel ionic cross-linked sulfonated poly(ether ether ketone) containing equal content of sulfonic acid and pendant tertiary amine groups (TA-SPEEK) has been initially synthesized for the application in direct methanol fuel cells (DMFCs). By adjusting the ratio of p-xylene dibromide to tertiary amine groups of TA-SPEEK, a series of ionic-covalent cross-linked membranes (C-SPEEK-x) with tunable degree of cross-linking are prepared. Compared with the pristine membrane, the ionic and ionic-covalent cross-linked proton exchange membranes (PEMs) exhibit reduced methanol permeability and improved mechanical properties, dimensional and oxidative stability. The proton conductivity and methanol selectivity of protonated TA-SPEEK and C-SPEEK-x at 25 °C is up to 0.109 S cm-1 and 3.88 × 105 S s cm-3, respectively, which are higher than that of Nafion 115. The DMFC incorporating C-SPEEK-25 exhibits a maximum power density as high as 35.3 mW cm-2 with 4 M MeOH at 25 °C (31.8 mW cm-2 for Nafion 115). Due to the highly oxidative stability of the membrane, no obvious performance degradation of the DMFC is observed after more than 400 h operation, indicating such cost-effective ionic-covalent cross-linked membranes have substantial potential as alternative PEMs for DMFC applications.

  16. The influence of methanol on the chemical state of PtRu anodes in a high-temperature direct methanol fuel cell studied in situ by synchrotron-based near-ambient pressure x-ray photoelectron spectroscopy

    Science.gov (United States)

    Saveleva, Viktoriia A.; Daletou, Maria K.; Savinova, Elena R.

    2017-01-01

    Synchrotron radiation-based near-ambient pressure x-ray photoelectron spectroscopy (NAP-XPS) has recently become a powerful tool for the investigation of interfacial phenomena in electrochemical power sources such as batteries and fuel cells. Here we present an in situ NAP-XPS study of the anode of a high-temperature direct methanol fuel cell with a phosphoric acid-doped hydrocarbon membrane, which reveals an enhanced flooding of the Pt3Ru anode with phosphoric acid in the presence of methanol. An analysis of the electrode surface composition depending on the cell voltage and on the presence of methanol reveals the strong influence of the latter on the extent of Pt oxidation and on the transformation of Ru into Ru (IV) hydroxide.

  17. Highly Dispersed Palladium Nanoparticles on Functional MWNT Surfaces for Methanol Oxidation in Alkaline Solutions

    Institute of Scientific and Technical Information of China (English)

    WANG zhe; ZHU Zan-Zan; LI You-Xiang; LI Hu-Lin

    2008-01-01

    Palladium nanoparticles were crystallized on 4-aminobenzoic acid monolayer-grafted multi-walled carbon nanotubes (MWNT) by diazotization. The structure and nature of the resulting Pd/MWNT composite were characterized by transmission electron microscopy and X-ray diffraction, the results show that the chemically synthesized Pd nanoparticles were homogeneously dispersed and well-separated from one another on the modified MWNT surfaces. Cyclic voltammogram showed that the Pd-MWNT composite materials performed higher electrocatalytic activity and better long-term stability toward methanol oxidation in alkaline solution than Pd-C. The results imply that the Pd-MWNT composite materials as a promising support material improve the excellent electrocatalytic activity for methanol oxidation greatly. So the Pd/MWNT composites have a good application potential to fuel cells.

  18. Study on the Stability of high pure Chiorogenic Acid%高纯度绿原酸的稳定性研究

    Institute of Scientific and Technical Information of China (English)

    涂北平; 赖卫华

    2011-01-01

    Objective:To investigate the stability of high pure chlorogenic acid in different conditions. Method:The stability of high pure chlorogenic acid in different antioxidants( sodium hydrogensulfite 、sodium pymsulfite 、L- cysteine monohydrochloride 、 ascorbic acid ), phosptat buffe with different pH values, organic solvents ( methanol 、ethanol), copper ions and complexing agent and β - cyclodextrins was investigated by the classical isothermal method. Result: The experiments showed the high pure chlorogenic acid was the most stable in L - cysteine monohydrochloride than in others antioxidants. It was more stable in acidic water than in basic water. It was stable in these organic solvents. The copper ions and complexing agents have certain stimulative effect on the stability of chlorogenic acid. Conclusion: In different conditions, the stability of high pure chlorogenic acid was different. It prodded a reference to the extraction and analysis of chlorogenic acid and production of chlorogenic acid preparation.%目的:研究高纯度绿原酸在不同条件下的稳定性。方法:采用高纯度绿原酸在抗氧化剂(亚硫酸氢钠、焦亚硫酸钠、L一半胱胺酸盐、维生素c)、不同pH值磷酸盐缓冲液、有机溶剂(甲醇、乙醇)、金属铜离子及络合剂及13一环糊精中的稳定性。结果:绿原酸在抗氧化剂L一半胱胺酸盐中最稳定,在酸性环境较碱性环境中更稳定,在上述有机溶剂中稳定,在金属铜离子与络合剂复合体对绿原酸影响稳定性有一定的促进作用。结论:高纯度绿原酸在不同条件下稳定性不同,该结果可为绿原酸的提取、分析及其相关制剂的生产提供参考。

  19. Value of high-frequency ultrasonography with virtual touch tissue quantification in diagnosis of breast pure mucinous carcinomas

    Institute of Scientific and Technical Information of China (English)

    Jian Shi; Guang Yang; Jialing Wu; Wenlin Xu

    2012-01-01

    Objective: The aim of our study was to analyze the characters of breast pure mucinous carcinomas on highfrequency ultrasonography with virtual touch tissue quantification (VTQ). Methods: A total of 12 patients (with breast pure mucinous carcinomas) and a group of 30 patients (with adenofibroma of breast) underwent breast examination with high-frequency ultrasonography to analyze the characters of images, and with VTQ to analyze the elastic character. Results: In the conventional ultrasound imaging, statistical differences were found between two groups in the shape, the boundary and the internal echo of the lesions. In the VTQ, the mean of shearing wave speed (Vs) in pure mucinous carcinomas was less than in adenofibroma of breast. Conclusion: Conventional high-frequency ultrasonography combining with VTQ have significant value in diagnosis of breast pure mucinous carcinoma.

  20. Acid resistance of methanogenic bacteria in a two-stage anaerobic process treating high concentration methanol Wastewater

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xuefei; REN Nanqi

    2007-01-01

    In this study,the two-stage upflow anaerobic sludge blanket(UASB)system and batch experiments were employed to evaluate the performance of anaerobic digestion for the treatment of high concentration methanol wastewater.The acid resistance of granular sludge and methanogenic bacteria and their metabolizing activity were investigated.The results show that the pH of the first UASB changed from 4.9 to 5.8 and 5.5 to 6.2 for the second reactor.Apparently,these were not the advisable pH levels that common metha nogenic bacteria could accept.The methanogenic bacteria of the system,viz.Methanosarcina barkeri,had some acid resistance and could still degrade methanol at pH 5.0.If the methanogenic bacteria were trained further,their acid resistance would be improved somewhat.Granular sludge of the system could protect the methanogenic bacteria within its body against the impact of the acidic environment and make them degrade methanol at pH 4.5.The performance of granular sludge was attributed to its structure,bacteria species,and the distribution of bacterium inside the granule.

  1. Methanol as an energy carrier

    Energy Technology Data Exchange (ETDEWEB)

    Biedermann, P.; Grube, T.; Hoehlein, B. (eds.)

    2006-07-01

    For the future, a strongly growing energy demand is expected in the transport sector worldwide. Economically efficient oil production will run through a maximum in the next decade. Higher fuel prices and an environmentally desirable reduction of emissions will increase the pressure for reducing fuel consumption and emissions in road traffic. These criteria show the urgent necessity of structural changes in the fuel market. Due to its advantages concerning industrial-scale production, storage and global availability, methanol has the short- to medium-term potential for gaining increased significance as a substitution product in the energy market. Methanol can be produced both from fossil energy sources and from biomass or waste materials through the process steps of synthesis gas generation with subsequent methanol synthesis. Methanol has the potential to be used in an environmentally friendly manner in gasoline/methanol mixtures for flexible fuel vehicles with internal combustion engines and in diesel engines with pure methanol. Furthermore, it can be used in fuel cell vehicles with on-board hydrogen production in direct methanol fuel cell drives, and in stationary systems for electricity and heat generation as well as for hydrogen production. Finally, in portable applications it serves as an energy carrier for electric power generation. In this book, the processes for the production and use of methanol are presented and evaluated, markets and future options are discussed and issues of safety and environmental impacts are addressed by a team of well-known authors. (orig.)

  2. Generation of an ultralong pure longitudinal magnetization needle with high axial homogeneity using an azimuthally polarized beam modulated by pure multi-zone plate phase filter

    Science.gov (United States)

    Yan, Weichao; Nie, Zhongquan; Zhang, Xueru; Wang, Yuxiao; Song, Yinglin

    2017-08-01

    Based on the vector diffraction theory and the inverse Faraday effect in the magneto-optic film, light-induced magnetization distributions, for a high numerical aperture focusing configuration with an azimuthally polarized beam modulated by an optimized pure multi-zone plate phase filter, are investigated. By making use of the compeletely destructive interference of its inter circle with the π phase shift between adjacent sub-annuli, and the capability to extend the constructive interference in the propagating direction through its narrow outer annulus modulated by three misplaced helical phases, an ultralong (107λ ) magnetization needle with both transverse super-resolution (0.37λ ) and uniform axial field strength is achieved in the focal region. The perfect magnetization needle and the accessible method give a guide for ultrahigh density magnetic storage, fabricating magnetic lattices for spin wave operation, as well as atomic trapping.

  3. Control and experimental characterization of a methanol reformer for a 350W high temperature polymer electrolyte membrane fuel cell system

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen; Jensen, Hans-Christian Becker

    High temperature polymer electrolyte membrane(HTPEM) fuel cells offer many advantages due to their increased operating tempera-tures compared to similar Nafion-based membrane tech-nologies, that rely on the conductive abilities of liquid water. The polybenzimidazole (PBI) membranes are especially...... suited for reformer systems, where high CO tolerance is required. This enables the use fuels based on e.g. liquid alcohols. This work presents the control strategies of a methanol refoermer for a 350W HTPEM FC system. The system examined is the Serenergy H3-350 Mobile Battery Charger, an integrated...

  4. Ultra high hole mobilities in a pure strained Ge quantum well

    Energy Technology Data Exchange (ETDEWEB)

    Mironov, O.A., E-mail: OAMironov@yahoo.co.uk [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); International Laboratory of High Magnetic Fields and Low Temperatures, 53-421 Wroclaw (Poland); Hassan, A.H.A. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Department of Physics, Tripoli University, Tripoli (Libya); Morris, R.J.H.; Dobbie, A. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Uhlarz, M. [High Magnetic Field Laboratory, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden (Germany); Chrastina, D. [L-NESS Politecnico di Milano, Polo di Como, Via Anzani 42, 22100 Como (Italy); Hague, J.P. [Department of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Kiatgamolchai, S. [Department of Physics, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok 10330 (Thailand); Beanland, R. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Gabani, S. [Centre of Low Temperature Physics, Institute of Experimental Physics SAS, Košice (Slovakia); Berkutov, I.B. [B.I. Verkin Institute for Low Temperature Physics and Engineering of NAS of Ukraine, Kharkov (Ukraine); Helm, M.; Drachenko, O. [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden (Germany); Myronov, M.; Leadley, D.R. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom)

    2014-04-30

    Hole mobilities at low and room temperature (RT) have been studied for a strained sGe/SiGe heterostructure using standard Van der Pauw resistivity and Hall effect measurements. The range of magnetic field and temperatures used were − 14 T < B < + 14 T and 1.5 K < T < 300 K respectively. Using maximum entropy-mobility spectrum analysis (ME-MSA) and Bryan's algorithm mobility spectrum (BAMS) analysis, a RT two dimensional hole gas drift mobility of (3.9 ± 0.4) × 10{sup 3} cm{sup 2}/V s was determined for a sheet density (p{sub s}) 9.8 × 10{sup 10} cm{sup −2} (by ME-MSA) and (3.9 ± 0.2) × 10{sup 3} cm{sup 2}/V s for a sheet density (p{sub s}) 5.9 × 10{sup 10} cm{sup −2} (by BAMS). - Highlights: • Pure strained Ge channel grown by reduced pressure chemical vapor deposition • Maximum entropy-mobility spectrum analysis • Bryan's algorithm mobility spectrum analysis • High room temperature hole drift mobility of (3.9 ± 0.4) × 10{sup 3} cm{sup 2}/V s • Extremely high hole mobility of 1.1 × 10{sup 6} cm{sup 2}/V s at 12 K.

  5. Obtaining the highly pure barium titanate nanocrystals by a new approach

    Energy Technology Data Exchange (ETDEWEB)

    Ashiri, Rouholah, E-mail: ro_ashiri@yahoo.com; Heidary Moghadam, Ali; Ajami, Reza

    2015-11-05

    Purity and synthesis temperature of nanocrystals are key challenges facing the scientific community. Herein a novel solid-state approach to synthesize fine BaTiO{sub 3} nanocrystals with narrow size distribution using a high-speed ball-milling process is reported. In order to improve the kinetics of this reaction, the starting materials, BaCO{sub 3} and TiO{sub 2}, were milled for 10 h before mixing and initiating the synthesis reaction. The contribution of this step to the BaTiO{sub 3} formation is analyzed by XRD diffractometry and FE-SEM techniques. It was found that the use of the mechanically activated starting materials favors the decomposition of BaCO{sub 3} at low temperatures and improves the Ba{sup 2+} diffusion through the formed BaTiO{sub 3} layer. In consequence, very fine BaTiO{sub 3} nanocrystals free from the secondary phases were obtained at a lower temperature in contrast to the previous works. - Highlights: • Very fine BaTiO{sub 3} nanocrystals were obtained at a lower temperature. • Method is able to obtain highly-pure BTO nanocrystals. • The approach is simple, and useful for large-scale production purposes.

  6. Characterisation of micro direct methanol fuel cells with silicon plate supported integrated ionomer membranes

    DEFF Research Database (Denmark)

    Larsen, Jackie Vincent; Dalslet, Bjarke Thomas; Kallesee, C.

    2013-01-01

    This work deals with the investigation and fabrication of Micro Direct Methanol Fuel Cells (μDMFC). They are investigated as a possible alternative for zinc-air batteries in small size consumer devices such as hearing aids. In such devices the conventional rechargeable batteries such as lithium......-ion batteries have insufficiently low energy density in the range 240 Wh/L to 300 Wh/L Methanol is a promising fuel for such devices due to the high energy density, with pure methanol having an energy density of 4400 Wh/L. Using a liquid fuel also allows refueling, which can be achieved much faster than battery...

  7. High-pressure thermal sterilization: food safety and food quality of baby food puree.

    Science.gov (United States)

    Sevenich, Robert; Kleinstueck, Elke; Crews, Colin; Anderson, Warwick; Pye, Celine; Riddellova, Katerina; Hradecky, Jaromir; Moravcova, Eliska; Reineke, Kai; Knorr, Dietrich

    2014-02-01

    The benefits that high-pressure thermal sterilization offers as an emerging technology could be used to produce a better overall food quality. Due to shorter dwell times and lower thermal load applied to the product in comparison to the thermal retorting, lower numbers and quantities of unwanted food processing contaminants (FPCs), for example, furan, acrylamide, HMF, and MCPD-esters could be formed. Two spore strains were used to test the technique; Geobacillus stearothermophilus and Bacillus amyloliquefaciens, over the temperature range 90 to 121 °C at 600 MPa. The treatments were carried out in baby food puree and ACES-buffer. The treatments at 90 and 105 °C showed that G. stearothermophilus is more pressure-sensitive than B. amyloliquefaciens. The formation of FPCs was monitored during the sterilization process and compared to the amounts found in retorted samples of the same food. The amounts of furan could be reduced between 81% to 96% in comparison to retorting for the tested temperature pressure combination even at sterilization conditions of F₀-value in 7 min.

  8. Absorption cross-section measurements of methane, ethane, ethylene and methanol at high temperatures

    KAUST Repository

    Alrefae, Majed

    2014-09-01

    Mid-IR absorption cross-sections are measured for methane, ethane, ethylene and methanol over 2800-3400 cm-1 (2.9-3.6 μm) spectral region. Measurements are carried out using a Fourier-Transform-Infrared (FTIR) spectrometer with temperatures ranging 296-1100 K and pressures near atmospheric. As temperature increases, the peak cross-sections decrease but the wings of the bands increase as higher rotational lines appear. Integrated band intensity is also calculated over the measured spectral region and is found to be a very weak function of temperature. The absorption cross-sections of the relatively small fuels studied here show dependence on the bath gas. This effect is investigated by studying the variation of absorption cross-sections at 3.392 μm using a HeNe laser in mixtures of fuel and nitrogen, argon, or helium. Mixtures of fuel with He have the highest value of absorption cross-sections followed by Ar and N2. Molecules with narrow absorption lines, such as methane and methanol, show strong dependence on bath gas than molecules with relatively broader absorption features i.e. ethane and ethylene. © 2014 Elsevier Inc. All rights reserved.

  9. Absorption cross-section measurements of methane, ethane, ethylene and methanol at high temperatures

    Science.gov (United States)

    Alrefae, Majed; Es-sebbar, Et-touhami; Farooq, Aamir

    2014-09-01

    Mid-IR absorption cross-sections are measured for methane, ethane, ethylene and methanol over 2800-3400 cm-1 (2.9-3.6 μm) spectral region. Measurements are carried out using a Fourier-Transform-Infrared (FTIR) spectrometer with temperatures ranging 296-1100 K and pressures near atmospheric. As temperature increases, the peak cross-sections decrease but the wings of the bands increase as higher rotational lines appear. Integrated band intensity is also calculated over the measured spectral region and is found to be a very weak function of temperature. The absorption cross-sections of the relatively small fuels studied here show dependence on the bath gas. This effect is investigated by studying the variation of absorption cross-sections at 3.392 μm using a HeNe laser in mixtures of fuel and nitrogen, argon, or helium. Mixtures of fuel with He have the highest value of absorption cross-sections followed by Ar and N2. Molecules with narrow absorption lines, such as methane and methanol, show strong dependence on bath gas than molecules with relatively broader absorption features i.e. ethane and ethylene.

  10. A Mercury-Catalyzed, High-Yield System for the Oxidation of Methane to Methanol

    Science.gov (United States)

    Periana, Roy A.; Taube, Douglas J.; Evitt, Eric R.; Loffler, Daniel G.; Wentrcek, Paul R.; Voss, George; Masuda, Toshihiko

    1993-01-01

    A homogeneous system for the selective, catalytic oxidation of methane to methanol via methyl bisulfate is reported. The net reaction catalyzed by mercuric ions, Hg(II), is the oxidation of methane by concentrated sulfuric acid to produce methyl bisulfate, water, and sulfur dioxide. The reaction is efficient. At a methane conversion of 50 percent, 85 percent selectivity to methyl bisulfate (~43 percent yield; the major side product is carbon dioxide) was achieved at a molar productivity of 10-7 mole per cubic centimeter per second and Hg(II) turnover frequency of 10-3 per second. Separate hydrolysis of methyl bisulfate and reoxidation of the sulfur dioxide with air provides a potentially practical scheme for the oxidation of methane to methanol with molecular oxygen. The primary steps of the Hg(II)-catalyzed reaction were individually examined and the essential elements of the mechanism were identified. The Hg(II) ion reacts with methane by an electrophilic displacement mechanism to produce an observable species, CH_3HgOSO_3H, 1. Under the reaction conditions, 1 readily decomposes to CH_3OSO_3H and the reduced mercurous species, Hg_22+. The catalytic cycle is completed by the reoxidation of Hg_22+ with H_2SO_4 to regenerate Hg(II) and byproducts SO_2 and H_2O. Thallium(III), palladium(II), and the cations of platinum and gold also oxidize methane to methyl bisulfate in sulfuric acid.

  11. Investigation of methanol oxidation on a highly active and stable Pt–Sn electrocatalyst supported on carbon–polyaniline composite for application in a passive direct methanol fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Amani, Mitra [Department of Chemical Engineering, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Kazemeini, Mohammad [Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Hamedanian, Mahboobeh [Department of Chemistry, Faculty of Science, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Pahlavanzadeh, Hassan [Department of Chemical Engineering, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Gharibi, Hussein, E-mail: h.gharibi@utah.edu [Department of Chemistry, Faculty of Science, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Department of Material Science & Engineering, 122 S Campus Drive, University of Utah, Salt Lake City, UT 84112 (United States)

    2015-08-15

    Highlights: • PtSn/C-PANI performed superior in the MOR compared with a commercial PtRu/C. • Catalytic activity of PtRu/C was highly reduced during the accelerated durability test. • Anode of the PtSn/C-PANI in a passive DMFC lowered methanol crossover by 30%. - Abstract: Polyaniline fiber (PANI) was synthesized and utilized to fabricate a vulcan–polyaniline (C-PANI) composite. Pt/C-PANI and PtSn/C-PANI electro-catalysts with different Pt:Sn atomic ratios were prepared by the impregnation method. These electro-catalysts, along with commercial PtRu/C (Electrochem), were characterized with respect to their structural and electrochemical properties in methanol oxidation reaction (MOR). PtSn(70:30)/C-PANI showed excellent performance in MOR, the obtained maximum current density being about 40% and 50% higher than that for PtRu/C and Pt/C-PANI, respectively. It was also found that the CO tolerance and stability of PtSn(70:30)/C-PANI was considerably higher than that of PtRu/C. Finally, the performance of these two materials was compared in a passive direct methanol fuel cell (DMFC). The DMFC test results demonstrated that the membrane electrode assembly (MEA) prepared using PtSn(70:30)/C-PANI anode catalyst performed more satisfactorily in terms of maximum power density and lower methanol crossover.

  12. Combined high-pressure and thermal treatments for processing of tomato puree : evaluation of microbial inactivation and quality parameters

    NARCIS (Netherlands)

    Krebbers, B.; Matser, A.M.; Hoogerwerf, S.W.; Moezelaar, R.; Tomassen, M.M.M.; Berg, van den R.W.

    2003-01-01

    The effects of combined high-pressure thermal treatments on consistency, viscosity, colour, lycopene content, enzyme activity and micro-organisms were determined, and compared to conventional pasteurisation and sterilisation processes of tomato puree. High-pressure processing at ambient temperature

  13. Dynamics of methanol in ionic liquids: validity of the Stokes-Einstein and Stokes-Einstein-Debye relations.

    Science.gov (United States)

    Herold, Elisabeth; Strauch, Matthias; Michalik, Dirk; Appelhagen, Andreas; Ludwig, Ralf

    2014-10-06

    The validity of Stokes-Einstein (SE) and Stokes-Einstein-Debye (SED) relations for methanol in the physical environment of the ionic liquid (IL) 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide is studied by means of nuclear magnetic resonance (NMR) relaxation time experiments, viscosity measurements and molecular dynamics (MD) simulations. The reorientational correlation times of the hydroxyl groups of pure methanol and of methanol in the IL/methanol mixtures were determined. For that purpose an approach for estimating NMR deuteron quadrupole coupling constants, presented by Wendt and Farrar (Mol. Phys. 1998, 95, 1077-1081), was confirmed. The self-diffusion coefficients of methanol were taken from the MD simulations. The viscosities of all systems were then measured and the SE and SED relations validated. For pure methanol both relations are valid, whereas they become increasingly invalid with increasing IL concentration, as indicated by effective volumes and radii that are too low. The deviation from the SE and SED relations could be related to dynamical heterogeneities described by the non-Gaussian parameter α(t) obtained from MD simulations. For pure methanol, α(t) is close to zero in accord with the validity of both relations. With increasing IL concentration the dynamical heterogeneities of methanol increase strongly. The times t* at the maximum of α(t) increase linearly with the relative number of methanol monomers in the mixtures. Thus, the dynamical heterogeneities are largest for single methanol molecules fully embedded in the IL environment. In their own environment methanol molecules are highly mobile, whereas in the IL-rich region the mobility is strongly reduced leading to the non-validity of SE and SED relations.

  14. High hydrostatic pressure processing reduces the glycemic index of fresh mango puree in healthy subjects.

    Science.gov (United States)

    Elizondo-Montemayor, Leticia; Hernández-Brenes, Carmen; Ramos-Parra, Perla A; Moreno-Sánchez, Diana; Nieblas, Bianca; Rosas-Pérez, Aratza M; Lamadrid-Zertuche, Ana C

    2015-04-01

    Dietary guidelines recommend the daily consumption of fruits; however, healthy and type 2 diabetes mellitus (T2DM) subjects receive conflicting messages regarding ingestion of fruits, such as mango, because of its sugar content. We investigated the effects of high hydrostatic pressure (HHP) processing of fresh mango puree (MP) on the glycemic indexes (GIs) and postprandial glycemic responses of 38 healthy Mexican subjects in a randomized cross-over clinical trial. Physicochemical characterization of MP included sugar profiles by HPLC-ELSD, starch, fibers, moisture, viscosity, swelling capacity and solubility properties of alcohol insoluble residue (AIR). The mean GI for HHP-MP was significantly lower (32.7 ± 13.4) than that of unprocessed-MP (42.7 ± 19.5). A significantly higher proportion of subjects showed a low GI following the consumption of HHP-MP compared to unprocessed-MP and none of them showed a high GI for the HHP-MP, compared to a significantly higher proportion for the unprocessed-MP. The viscosity and AIR solubility values of HHP-MP samples were significantly higher, which influenced glucose peaking later (Tmax) at 45 minutes and induced 20% lower AUC values than unprocessed-MP, corresponding to greater retardation indexes. The study findings support data stating that low GI fruits are appropriate for glycemic control and that mango may be included as part of healthy subjects' diets and potentially T2DM subjects' diets. Furthermore, HHP processing of mango may offer additional benefits for glycemic control, as its performance regarding GI, AUC and Tmax was significantly better than that of the unprocessed-MP. To our knowledge, this is the first report on the impact of this commercial non-thermal pasteurization technology on glucose metabolism.

  15. Formaldehyde and methanol deuteration in protostars: fossiles from a past fast high density pre-collapse phase

    CERN Document Server

    Taquet, Vianney; Kahane, Claudine

    2012-01-01

    Extremely high deuteration of several molecules have been observed around low mass protostars since a decade. Among them, formaldehyde and methanol present particularly high deuteration, with observations of abundant doubly and triply deuterated forms. Both species are thought to be mainly formed on interstellar grains during the low temperature and dense pre-collapse phase by H and D atom additions on the iced CO. We present here a theoretical study of the formaldehyde and methanol deuteration obtained with our gas-grain model, GRAINOBLE. This model takes into account the multilayer nature of the mantle and explores the robustness of the results against the uncertainties of poorly constrained chemical and surface model parameters. The comparison of the model predictions with the observations leads to two major results: i) the observed high deuteration is obtained during the last phase of the pre-collapse stage, when the density reaches 5 10^6 cm^-3, and this phase is fast, lasting only several thousands year...

  16. FORMALDEHYDE AND METHANOL DEUTERATION IN PROTOSTARS: FOSSILS FROM A PAST FAST HIGH-DENSITY PRE-COLLAPSE PHASE

    Energy Technology Data Exchange (ETDEWEB)

    Taquet, V.; Ceccarelli, C.; Kahane, C. [UJF-Grenoble 1/CNRS-INSU, Institut de Planetologie et d' Astrophysique de Grenoble (IPAG) UMR 5274, F-38041 Grenoble (France)

    2012-03-20

    Extremely high deuteration of several molecules has been observed around low-mass protostars for a decade. Among them, formaldehyde and methanol present particularly high deuteration, with observations of abundant doubly and triply deuterated forms. Both species are thought to be mainly formed on interstellar grains during the low-temperature and dense pre-collapse phase by H and D atom additions on the iced CO. We present here a theoretical study of the formaldehyde and methanol deuteration obtained with our gas-grain model, GRAINOBLE. This model takes into account the multilayer nature of the mantle and explores the robustness of the results against the uncertainties of poorly constrained chemical and surface model parameters. The comparison of the model predictions with the observations leads to two major results: (1) the observed high deuteration is obtained during the last phase of the pre-collapse stage, when the density reaches {approx}5 Multiplication-Sign 10{sup 6} cm{sup -3}, and this phase is fast, lasting only several thousands years; and (2) D and H abstraction and substitution reactions are crucial in making up the observed deuteration ratios. This work shows the power of chemical composition as a tool to reconstruct the past history of protostars.

  17. Physiological response of Pichia pastoris GS115 to methanol-induced high level production of the Hepatitis B surface antigen: catabolic adaptation, stress responses, and autophagic processes

    Directory of Open Access Journals (Sweden)

    Vanz Ana Leticia

    2012-08-01

    Full Text Available Abstract Background Pichia pastoris is an established eukaryotic host for the production of recombinant proteins. Most often, protein production is under the control of the strong methanol-inducible aox1 promoter. However, detailed information about the physiological alterations in P. pastoris accompanying the shift from growth on glycerol to methanol-induced protein production under industrial relevant conditions is missing. Here, we provide an analysis of the physiological response of P. pastoris GS115 to methanol-induced high-level production of the Hepatitis B virus surface antigen (HBsAg. High product titers and the retention of the protein in the endoplasmic reticulum (ER are supposedly of major impact on the host physiology. For a more detailed understanding of the cellular response to methanol-induced HBsAg production, the time-dependent changes in the yeast proteome and ultrastructural cell morphology were analyzed during the production process. Results The shift from growth on glycerol to growth and HBsAg production on methanol was accompanied by a drastic change in the yeast proteome. In particular, enzymes from the methanol dissimilation pathway started to dominate the proteome while enzymes from the methanol assimilation pathway, e.g. the transketolase DAS1, increased only moderately. The majority of methanol was metabolized via the energy generating dissimilatory pathway leading to a corresponding increase in mitochondrial size and numbers. The methanol-metabolism related generation of reactive oxygen species induced a pronounced oxidative stress response (e.g. strong increase of the peroxiredoxin PMP20. Moreover, the accumulation of HBsAg in the ER resulted in the induction of the unfolded protein response (e.g. strong increase of the ER-resident disulfide isomerase, PDI and the ER associated degradation (ERAD pathway (e.g. increase of two cytosolic chaperones and members of the AAA ATPase superfamily indicating that potential

  18. Comprehensive characterization and understanding of micro-fuel cells operating at high methanol concentrations.

    Science.gov (United States)

    Gago, Aldo S; Esquivel, Juan-Pablo; Sabaté, Neus; Santander, Joaquín; Alonso-Vante, Nicolas

    2015-01-01

    We report on the analysis of the performance of each electrode of an air-breathing passive micro-direct methanol fuel cell (µDMFC) during polarization, stabilization and discharge, with CH3OH (2-20 M). A reference electrode with a microcapillary was used for separately measuring the anode the cathode potential. Information about the open circuit potential (OCP), the voltage and the mass transport related phenomena are available. Using 2 M CH3OH, the anode showed mass transport problems. With 4 and 6 M CH3OH both electrodes experience this situation, whereas with 10 and 20 M CH3OH the issue is attributed to the cathode. The stabilization and fuel consumption time depends mainly on the cathode performance, which is very sensitive to fuel crossover. The exposure to 20 M CH3OH produced a loss in performance of more than 75% of the highest power density (16.3 mW·cm(-2)).

  19. Nafion Titania Nanotubes Nanocomposite Electrolytes for High-Temperature Direct Methanol Fuel Cells

    Directory of Open Access Journals (Sweden)

    Nonhlanhla Precious Cele

    2012-01-01

    Full Text Available Nafion-based nanocomposite membranes containing various amounts of titania nanotubes (TNTs as an inorganic filler have been prepared using melt-mixing method and have been investigated for proton exchange membrane applications. The one-dimensional TNTs have been prepared from potassium hydroxide using hydrothermal route and conventional heating. Nafion R1100 in a protonated form was used, and TNT contents were in a range of 0.5–2.0 wt%. The acid-treated composite membranes, at lowest inorganic additive content, exhibited improved properties in terms of thermal stability and methanol (MeOH permeability. The best performing nanocomposite was the membrane containing only 0.5 wt% TNTs showing ionic conductivity value of 7.2×10-2 S·cm-1 at 26°C and 100% of relative humidity.

  20. Investigation into the Advantages of Pure Perovskite Film without PbI2 for High Performance Solar Cell.

    Science.gov (United States)

    Kwon, Uisik; Hasan, Md Mehedi; Yin, Wenping; Kim, Dasom; Ha, Na Young; Lee, Soonil; Ahn, Tae Kyu; Park, Hui Joon

    2016-10-27

    In CH3NH3PbI3-based high efficiency perovskite solar cells (PSCs), tiny amount of PbI2 impurity was often found with the perovskite crystal. However, for two-step solution process-based perovskite films, most of findings have been based on the films having different morphologies between with and without PbI2. This was mainly due to the inferior morphology of pure perovskite film without PbI2, inevitably produced when the remaining PbI2 forced to be converted to perovskite, so advantages of pure perovskite photoactive layer without PbI2 impurity have been overlooked. In this work, we designed a printing-based two-step process, which could not only generate pure perovskite crystal without PbI2, but also provide uniform and full surface coverage perovskite film, of which nanoscale morphology was comparable to that prepared by conventional two-step solution process having residual PbI2. Our results showed that, in two-step solution process-based PSC, pure perovskite had better photon absorption and longer carrier lifetime, leading to superior photocurrent generation with higher power conversion efficiency. Furthermore, this process was further applicable to prepare mixed phase pure perovskite crystal without PbI2 impurity, and we showed that the additional merits such as extended absorption to longer wavelength, increased carrier lifetime and reduced carrier recombination could be secured.

  1. Investigation into the Advantages of Pure Perovskite Film without PbI2 for High Performance Solar Cell

    Science.gov (United States)

    Kwon, Uisik; Hasan, Md Mehedi; Yin, Wenping; Kim, Dasom; Ha, Na Young; Lee, Soonil; Ahn, Tae Kyu; Park, Hui Joon

    2016-10-01

    In CH3NH3PbI3-based high efficiency perovskite solar cells (PSCs), tiny amount of PbI2 impurity was often found with the perovskite crystal. However, for two-step solution process-based perovskite films, most of findings have been based on the films having different morphologies between with and without PbI2. This was mainly due to the inferior morphology of pure perovskite film without PbI2, inevitably produced when the remaining PbI2 forced to be converted to perovskite, so advantages of pure perovskite photoactive layer without PbI2 impurity have been overlooked. In this work, we designed a printing-based two-step process, which could not only generate pure perovskite crystal without PbI2, but also provide uniform and full surface coverage perovskite film, of which nanoscale morphology was comparable to that prepared by conventional two-step solution process having residual PbI2. Our results showed that, in two-step solution process-based PSC, pure perovskite had better photon absorption and longer carrier lifetime, leading to superior photocurrent generation with higher power conversion efficiency. Furthermore, this process was further applicable to prepare mixed phase pure perovskite crystal without PbI2 impurity, and we showed that the additional merits such as extended absorption to longer wavelength, increased carrier lifetime and reduced carrier recombination could be secured.

  2. Investigation into the Advantages of Pure Perovskite Film without PbI2 for High Performance Solar Cell

    Science.gov (United States)

    Kwon, Uisik; Hasan, Md Mehedi; Yin, Wenping; Kim, Dasom; Ha, Na Young; Lee, Soonil; Ahn, Tae Kyu; Park, Hui Joon

    2016-01-01

    In CH3NH3PbI3-based high efficiency perovskite solar cells (PSCs), tiny amount of PbI2 impurity was often found with the perovskite crystal. However, for two-step solution process-based perovskite films, most of findings have been based on the films having different morphologies between with and without PbI2. This was mainly due to the inferior morphology of pure perovskite film without PbI2, inevitably produced when the remaining PbI2 forced to be converted to perovskite, so advantages of pure perovskite photoactive layer without PbI2 impurity have been overlooked. In this work, we designed a printing-based two-step process, which could not only generate pure perovskite crystal without PbI2, but also provide uniform and full surface coverage perovskite film, of which nanoscale morphology was comparable to that prepared by conventional two-step solution process having residual PbI2. Our results showed that, in two-step solution process-based PSC, pure perovskite had better photon absorption and longer carrier lifetime, leading to superior photocurrent generation with higher power conversion efficiency. Furthermore, this process was further applicable to prepare mixed phase pure perovskite crystal without PbI2 impurity, and we showed that the additional merits such as extended absorption to longer wavelength, increased carrier lifetime and reduced carrier recombination could be secured. PMID:27786257

  3. Inactivation of Salmonella enterica and Listeria monocytogenes in cantaloupe puree by high hydrostatic pressure with/without added ascorbic acid

    Science.gov (United States)

    The objective of this research was to evaluate and develop a method for inactivation of Salmonella enterica and Listeria monocytogenes in cantaloupe puree (CP) by high hydrostatic pressure (HHP). Cantaloupe being the most netted varieties of melons presents a greater risk of pathogen transmission. ...

  4. TiN@nitrogen-doped carbon supported Pt nanoparticles as high-performance anode catalyst for methanol electrooxidation

    Science.gov (United States)

    Zhang, Jun; Ma, Li; Gan, Mengyu; Fu, Shenna; Zhao, Yi

    2016-08-01

    In this paper, TiN@nitrogen-doped carbons (NDC) composed of a core-shell structure are successfully prepared through self-assembly and pyrolysis treatment using γ-aminopropyltriethoxysilane as coupling agent, polyaniline as carbon and nitrogen source, respectively. Subsequently, TiN@NDC supporting Pt nanoparticles (Pt/TiN@NDC) are obtained by a microwave-assisted polyol process. The nitrogen-containing functional groups and TiN nanoparticles play a critical role in decreasing the average particle size of Pt and improving the electrocatalytic activity of Pt/TiN@NDC. Transmission electron microscope results reveal that Pt nanoparticles are uniformly dispersed in the TiN@NDC surface with a narrow particle size ranging from 1 to 3 nm in diameter. Moreover, the Pt/TiN@NDC catalyst shows significantly improved catalytic activity and high durability for methanol electrooxidation in comparison with Pt/NDC and commercial Pt/C catalysts, revealed by cyclic voltammetry and chronoamperometry. Strikingly, this novel Pt/TiN@NDC catalyst reveals a better CO tolerance related to Pt/NDC and commercial Pt/C catalysts, which due to the bifunctional mechanism and strong metal-support interaction between Pt and TiN@NDC. In addition, the probable reaction steps for the electrooxidation of CO adspecies on Pt NPs on the basis of the bifunctional mechanism are also proposed. These results indicate that the TiN@NDC is a promising catalyst support for methanol electrooxidation.

  5. Facile and Rapid Synthesis of Ultrafine PtPd Bimetallic Nanoparticles and Their High Performance toward Methanol Electrooxidation

    Directory of Open Access Journals (Sweden)

    Tiantian Xia

    2014-01-01

    Full Text Available Uniform and sub-10 nm size bimetallic PtPd nanoparticles (NPs have been synthesized via a simple and facile method without using any surfactants at an ambient temperature. As a green and clean reductive agent, ascorbic acid (AA was employed for the coreduction of K2PtCl4 and K2PdCl4 in aqueous solution. The morphology, composition, and structure of PtPd NPs had been characterized by transmission electron microscopy (TEM, field emission high resolution transmission electron microscopy (FE-HRTEM, energy dispersive spectroscopy (EDS, X-ray diffraction (XRD, and X-ray photoelectron spectroscope (XPS. Comparing with both the monometallic Pt and Pd, the as-prepared alloy nanoparticles show superior electrocatalytic activity and better tolerance against poisoning by intermediates generated during methanol electrooxidation, which makes them a promising electrocatalysts for direct methanol fuel cells (DMFCs. Meanwhile, the green and simple approach could be easily extended to the manufacture of bimetallic or trimetallic alloy nanomaterials.

  6. Heat and fuel coupled operation of a high temperature polymer electrolyte fuel cell with a heat exchanger methanol steam reformer

    Science.gov (United States)

    Schuller, G.; Vázquez, F. Vidal; Waiblinger, W.; Auvinen, S.; Ribeirinha, P.

    2017-04-01

    In this work a methanol steam reforming (MSR) reactor has been operated thermally coupled to a high temperature polymer electrolyte fuel cell stack (HT-PEMFC) utilizing its waste heat. The operating temperature of the coupled system was 180 °C which is significantly lower than the conventional operating temperature of the MSR process which is around 250 °C. A newly designed heat exchanger reformer has been developed by VTT (Technical Research Center of Finland LTD) and was equipped with commercially available CuO/ZnO/Al2O3 (BASF RP-60) catalyst. The liquid cooled, 165 cm2, 12-cell stack used for the measurements was supplied by Serenergy A/S. The off-heat from the electrochemical fuel cell reaction was transferred to the reforming reactor using triethylene glycol (TEG) as heat transfer fluid. The system was operated up to 0.4 A cm-2 generating an electrical power output of 427 Wel. A total stack waste heat utilization of 86.4% was achieved. It has been shown that it is possible to transfer sufficient heat from the fuel cell stack to the liquid circuit in order to provide the needed amount for vaporizing and reforming of the methanol-water-mixture. Furthermore a set of recommendations is given for future system design considerations.

  7. Isotopic quantum effects in the structure of liquid methanol: I. Experiments with high-energy photon diffraction

    Science.gov (United States)

    Tomberli, B.; Egelstaff, P. A.; Benmore, C. J.; Neuefeind, J.

    2001-12-01

    High-energy electromagnetic radiation scattering techniques have been used to measure the structural differences between four isotopic samples of methanol (CH3OH, CD3OD, CH3OD and CD3OH). The first series of experiments employed room temperature and ambient pressure. The carbon-oxygen intramolecular bond length was measured and found to depend more strongly on the isotopic substitution at the hydroxyl site than at the methyl sites. The oscillations in the isotopic difference of the x-ray structure factor, ΔSX(Q), are shown at room temperature to be about 2% as large as the oscillations in the total structure factor. Our uncertainties are an order of magnitude smaller than those of previous gamma ray measurements (Benmore C J and Egelstaff P A 1996 J. Phys.: Condens. Matter 8 9429-32). A second series of experiments was carried out at -80 °C at its vapour pressure in order to study the significant temperature dependence of these effects. The ΔSX(Q) difference at -80 °C is shown to be up to three times larger than the room temperature difference. These studies showed that isotopic structural differences in methanol may be represented as temperature shifts that vary as a function of thermodynamic state and substitution site.

  8. The Relevance of the High Frequency Audiometry in Tinnitus Patients with Normal Hearing in Conventional Pure-Tone Audiometry.

    Science.gov (United States)

    Vielsmeier, Veronika; Lehner, Astrid; Strutz, Jürgen; Steffens, Thomas; Kreuzer, Peter M; Schecklmann, Martin; Landgrebe, Michael; Langguth, Berthold; Kleinjung, Tobias

    2015-01-01

    The majority of tinnitus patients suffer from hearing loss. But a subgroup of tinnitus patients show normal hearing thresholds in the conventional pure-tone audiometry (125 Hz-8 kHz). Here we explored whether the results of the high frequency audiometry (>8 kHz) provide relevant additional information in tinnitus patients with normal conventional audiometry by comparing those with normal and pathological high frequency audiometry with respect to their demographic and clinical characteristics. From the database of the Tinnitus Clinic at Regensburg we identified 75 patients with normal hearing thresholds in the conventional pure-tone audiometry. We contrasted these patients with normal and pathological high-frequency audiogram and compared them with respect to gender, age, tinnitus severity, pitch, laterality and duration, comorbid symptoms and triggers for tinnitus onset. Patients with pathological high frequency audiometry were significantly older and had higher scores on the tinnitus questionnaires in comparison to patients with normal high frequency audiometry. Furthermore, there was an association of high frequency audiometry with the laterality of tinnitus. In tinnitus patients with normal pure-tone audiometry the high frequency audiometry provides useful additional information. The association between tinnitus laterality and asymmetry of the high frequency audiometry suggests a potential causal role for the high frequency hearing loss in tinnitus etiopathogenesis.

  9. The Relevance of the High Frequency Audiometry in Tinnitus Patients with Normal Hearing in Conventional Pure-Tone Audiometry

    Directory of Open Access Journals (Sweden)

    Veronika Vielsmeier

    2015-01-01

    Full Text Available Objective. The majority of tinnitus patients suffer from hearing loss. But a subgroup of tinnitus patients show normal hearing thresholds in the conventional pure-tone audiometry (125 Hz–8 kHz. Here we explored whether the results of the high frequency audiometry (>8 kHz provide relevant additional information in tinnitus patients with normal conventional audiometry by comparing those with normal and pathological high frequency audiometry with respect to their demographic and clinical characteristics. Subjects and Methods. From the database of the Tinnitus Clinic at Regensburg we identified 75 patients with normal hearing thresholds in the conventional pure-tone audiometry. We contrasted these patients with normal and pathological high-frequency audiogram and compared them with respect to gender, age, tinnitus severity, pitch, laterality and duration, comorbid symptoms and triggers for tinnitus onset. Results. Patients with pathological high frequency audiometry were significantly older and had higher scores on the tinnitus questionnaires in comparison to patients with normal high frequency audiometry. Furthermore, there was an association of high frequency audiometry with the laterality of tinnitus. Conclusion. In tinnitus patients with normal pure-tone audiometry the high frequency audiometry provides useful additional information. The association between tinnitus laterality and asymmetry of the high frequency audiometry suggests a potential causal role for the high frequency hearing loss in tinnitus etiopathogenesis.

  10. Ignition and Combustion Characteristics of Diesel Spray in Premixed Methanol/Air Mixture with High Temperature%柴油在甲醇/空气高温热氛围中的着火和燃烧特性

    Institute of Scientific and Technical Information of China (English)

    姚春德; 代乾; 许汉君; 庄远; 杨广峰

    2012-01-01

    This paper reported the research on the ignition and combustion characteristics of diesel fuel in pure air premixed and methanol/air mixture in a constant volume combustion bomb, respectively. The experimental results showed that the ignition delay of diesel fuel was prolonged and the lift-off length of diesel fuel flame was extended in the premixed methanol ambient. Combustion of n-heptane and n-heptane mixed with methanol in zero-dimension model was simulated according to the reaction theory of n-heptane and methanol. The results showed that, with the addition of methanol, high temperature and low temperature exothermic reaction are delayed, ignition delay is prolonged, the peak value of low temperature exothermic reaction declined markedly without obvious negative temperature coefficient district, and the peak value of high temperature exothermic reaction is higher than that in the pure air. These phenomena are attributed to the effect of methanol which consumes hydroxyl radical and converts this active radical to inactive H2O2. So the reaction activity of the system before ignition is decreased. Both experiments and calculation illustrated that methanol plays a great important role in delaying the ignition of diesel.%在定容燃烧弹上进行了柴油分别在空气和在甲醇/空气预混均质混合气中着火燃烧的实验研究.结果表明,与空气热氛围相比,甲醇混合气热氛围延长了柴油的滞燃期和加长了火焰浮起高度.采用正庚烷-甲醇的详细化学反应机理,利用数值模拟的方法计算了零维模型中正庚烷及正庚烷加甲醇的燃烧反应过程和中间产物历程.其结果表明,甲醇的加入使得正庚烷的高低温放热反应开始时刻后移,滞燃期延长,低温放热反应峰值明显下降,且无明显的负温度系数区,高温反应放热峰值高于其在空气氛围中,归其原因在于甲醇大量消耗着火的OH自由基,并将其转化为低温氧化中不活跃的H2O2,使得

  11. Comprehensive characterization and understanding of micro-fuel cells operating at high methanol concentrations

    Directory of Open Access Journals (Sweden)

    Aldo S. Gago

    2015-10-01

    Full Text Available We report on the analysis of the performance of each electrode of an air-breathing passive micro-direct methanol fuel cell (µDMFC during polarization, stabilization and discharge, with CH3OH (2–20 M. A reference electrode with a microcapillary was used for separately measuring the anode the cathode potential. Information about the open circuit potential (OCP, the voltage and the mass transport related phenomena are available. Using 2 M CH3OH, the anode showed mass transport problems. With 4 and 6 M CH3OH both electrodes experience this situation, whereas with 10 and 20 M CH3OH the issue is attributed to the cathode. The stabilization and fuel consumption time depends mainly on the cathode performance, which is very sensitive to fuel crossover. The exposure to 20 M CH3OH produced a loss in performance of more than 75% of the highest power density (16.3 mW·cm−2.

  12. Highly Durable Direct Methanol Fuel Cell with Double-Layered Catalyst Cathode

    Directory of Open Access Journals (Sweden)

    Jing Liu

    2015-01-01

    Full Text Available Polymer electrolyte membrane (PEM is one of the key components in direct methanol fuel cells. However, the PEM usually gets attacked by reactive oxygen species during the operation period, resulting in the loss of membrane integrity and formation of defects. Herein, a double-layered catalyst cathode electrode consisting of Pt/CeO2-C as inner catalyst and Pt/C as outer catalyst is fabricated to extend the lifetime and minimize the performance loss of DMFC. Although the maximum power density of membrane electrode assembly (MEA with catalyst cathode is slightly lower than that of the traditional one, its durability is significantly improved. No obvious degradation is evident in the MEA with double-layered catalyst cathode within durability testing. These results indicated that Pt/CeO2-C as inner cathode catalyst layer greatly improved the stability of MEA. The significant reason for the improved stability of MEA is the ability of CeO2 to act as free-radical scavengers.

  13. Supported Pd-Cu bimetallic nanoparticles that have high activity for the electrochemical oxidation of methanol.

    Science.gov (United States)

    Yin, Zhen; Zhou, Wu; Gao, Yongjun; Ma, Ding; Kiely, Christopher J; Bao, Xinhe

    2012-04-16

    Monodisperse bimetallic Pd-Cu nanoparticles with controllable size and composition were synthesized by a one-step multiphase ethylene glycol (EG) method. Adjusting the stoichiometric ratio of the Pd and Cu precursors afforded nanoparticles with different compositions, such as Pd(85)-Cu(15), Pd(56)-Cu(44), and Pd(39)-Cu(61). The nanoparticles were separated from the solution mixture by extraction with non-polar solvents, such as n-hexane. Monodisperse bimetallic Pd-Cu nanoparticles with narrow size-distribution were obtained without the need for a size-selection process. Capping ligands that were bound to the surface of the particles were removed through heat treatment when the as-prepared nanoparticles were loaded onto a Vulcan XC-72 carbon support. Supported bimetallic Pd-Cu nanoparticles showed enhanced electrocatalytic activity towards methanol oxidation compared with supported Pd nanoparticles that were fabricated according to the same EG method. For a bimetallic Pd-Cu catalyst that contained 15 % Cu, the activity was even comparable to the state-of-the-art commercially available Pt/C catalysts. A STEM-HAADF study indicated that the formation of random solid-solution alloy structures in the bimetallic Pd(85)-Cu(15)/C catalysts played a key role in improving the electrochemical activity. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Void formation in pure aluminium irradiated with high-energetic electron beams and gamma-quanta

    DEFF Research Database (Denmark)

    Gan, V. V.; Ozhigou, L. S.; Yamnitsky, V. A.

    1983-01-01

    The spatial distribution of displaced atoms and helium atoms and also the spectra of damaging energies of primary displaced atoms in a thick aluminium target irradiated with electrons of 225 MeV energy were calculated. Pure aluminium (99.9999%) irradiated up to 0.04 dose was studied by electron-m......-microscopy. Voids of size 5 to 40 nm were obtained and their vacancy nature was estimated. The dislocation structure of the material was studied...

  15. 高杂质氰化金泥生产高纯金、高纯银实践%Practice of Extracting High Pure Gold and High Pure Silver from High Impurity Cyaniding Gold Mud

    Institute of Scientific and Technical Information of China (English)

    叶跃威

    2014-01-01

    Considering its high impurity, Suichang Gold Mine smelts the cyaniding gold mud using the following processes: remove copper and zinc by combined pickling of sulfuric acid and complexing agent; produce silver positive plate by using lead to capture the gold and silver in the reduction smelting atmosphere; separate gold, silver and lead through the first electrolysis of silver; treat the black gold powder by acid-alkali-combination method; high-acid and low-copper silver electrolysis process; asymmetric ac power applied to gold electrolysis process; and etc. By using this process, the content of high pure silver produced can reach up to more than 99.996%, the content of high pure gold produced is stably more than 99.997%, and the contents of impurities are far less than the state-specified standard of high pure gold, which is 99.999%. The flowsheet is simple and convenient to operate, and the quality of finished product of gold and silver is in the leading position nationwide.%遂昌金矿针对高杂质氰化金泥采用的工艺为:硫酸加络合剂联合酸洗除铜锌、还原熔炼气氛下铅捕集金银生产银阳极板、一次银电解过程实现金银铅的分离、酸碱联合处理黑金粉、高酸低铜银电解生产工艺、非对称交流电源用于金电解生产等。该工艺生产的高纯银达99.996%以上、高纯金的质量稳定在99.997%以上,杂质含量远远小于高纯金(99.999%)的要求,流程操作简单,成品金银质量在国内处于领先地位。

  16. The relevance of the high frequency audiometry in tinnitus patients with normal hearing in conventional pure-tone audiometry

    OpenAIRE

    Veronika Vielsmeier; Astrid Lehner; Jürgen Strutz; Thomas Steffens; Kreuzer, Peter M; Martin Schecklmann; Michael Landgrebe; Berthold Langguth; Tobias Kleinjung

    2015-01-01

    Objective. The majority of tinnitus patients suffer from hearing loss. But a subgroup of tinnitus patients show normal hearing thresholds in the conventional pure-tone audiometry (125 Hz–8 kHz). Here we explored whether the results of the high frequency audiometry (>8 kHz) provide relevant additional information in tinnitus patients with normal conventional audiometry by comparing those with normal and pathological high frequency audiometry with respect to their demographic and clinical chara...

  17. Improvement in methanol production by regulating the composition of synthetic gas mixture and raw biogas.

    Science.gov (United States)

    Patel, Sanjay K S; Mardina, Primata; Kim, Dongwook; Kim, Sang-Yong; Kalia, Vipin C; Kim, In-Won; Lee, Jung-Kul

    2016-10-01

    Raw biogas can be an alternative feedstock to pure methane (CH4) for methanol production. In this investigation, we evaluated the methanol production potential of Methylosinus sporium from raw biogas originated from an anaerobic digester. Furthermore, the roles of different gases in methanol production were investigated using synthetic gas mixtures of CH4, carbon dioxide (CO2), and hydrogen (H2). Maximum methanol production was 5.13, 4.35, 6.28, 7.16, 0.38, and 0.36mM from raw biogas, CH4:CO2, CH4:H2, CH4:CO2:H2, CO2, and CO2:H2, respectively. Supplementation of H2 into raw biogas increased methanol production up to 3.5-fold. Additionally, covalent immobilization of M. sporium on chitosan resulted in higher methanol production from raw biogas. This study provides a suitable approach to improve methanol production using low cost raw biogas as a feed containing high concentrations of H2S (0.13%). To our knowledge, this is the first report on methanol production from raw biogas, using immobilized cells of methanotrophs.

  18. OGLE-2016-BLG-0596Lb: High-Mass Planet From High-Magnification Pure-Survey Microlensing Event

    CERN Document Server

    Mróz, P; Udalski, A; Poleski, R; Skowron, J; Szymański, M K; Soszyński, I; Pietrukowicz, P; Kozłowski, S; Ulaczyk, K; Wyrzykowski, Ł; Pawlak, M; Albrow, M D; Cha, S -M; Chung, S -J; Jung, Y K; Kim, D -J; Kim, S -L; Lee, C -U; Lee, Y; Park, B -G; Pogge, R W; Ryu, Y -H; Shin, I -G; Yee, J C; Zhu, W; Gould, A

    2016-01-01

    We report the discovery of a high mass-ratio planet $q=0.012$, i.e., 13 times higher than the Jupiter/Sun ratio. The host mass is not presently measured but can be determined or strongly constrained from adaptive optics imaging. The planet was discovered in a small archival study of high-magnification events in pure-survey microlensing data, which was unbiased by the presence of anomalies. The fact that it was previously unnoticed may indicate that more such planets lie in archival data and could be discovered by similar systematic study. In order to understand the transition from predominantly survey+followup to predominately survey-only planet detections, we conduct the first analysis of these detections in the observational $(s,q)$ plane. Here $s$ is projected separation in units of the Einstein radius. We find some evidence that survey+followup is relatively more sensitive to planets near the Einstein ring, but that there is no statistical difference in sensitivity by mass ratio.

  19. Self-Decoration of PtNi Alloy Nanoparticles on Multiwalled Carbon Nanotubes for Highly Efficient Methanol Electro-Oxidation

    Institute of Scientific and Technical Information of China (English)

    Yu-Yan Zhou; Chang-Hai Liu; Jie Liu; Xin-Lei Cai; Ying Lu; Hui Zhang; Xu-Hui Sun; Sui-Dong Wang

    2016-01-01

    A simple one-pot method was developed to prepare PtNi alloy nanoparticles, which can be self-decorated on multiwalled carbon nanotubes in [BMIm][BF4] ionic liquid. The nanohybrids are targeting stable nanocatalysts for fuel cell applications. The sizes of the supported PtNi nanoparticles are uniform and as small as 1–2 nm. Pt-to-Ni ratio was controllable by simply selecting a PtNi alloy target. The alloy nanoparticles with Pt-to-Ni ratio of 1:1 show high catalytic activity and stability for methanol electro-oxidation. The performance is much higher compared with those of both Pt-only nanoparticles and commercial Pt/C catalyst. The electronic structure characterization on the PtNi nanoparticles demon-strates that the electrons are transferred from Ni to Pt, which can suppress the CO poisoning effect.

  20. Synthesis of highly phase pure (Bi, Pb)-Sr-Ca-Cu-O superconductor

    Science.gov (United States)

    Dorris, Stephen E.; Poeppel, Roger B.; Prorok, Barton C.; Lanagan, Michael T.; Maroni, Victor A.

    1994-01-01

    An article and method of manufacture of (Bi,Pb)-Sr-Ca-Cu-O superconductor. The superconductor is manufactured by preparing a first powdered mixture of bismuth oxide, lead oxide, strontium carbonate, calcium carbonate and copper oxide. A second powdered mixture is then prepared of strontium carbonate, calcium carbonate and copper oxide. The mixtures are calcined separately with the two mixtures then combined. The resulting combined mixture is then subjected to a powder in tube deformation and thermal processing to produce a substantially phase pure (Bi,Pb)-Sr-Ca-Cu-O superconductor.

  1. Control and Experimental Characterization of a Methanol Reformer for a 350 W High Temperature Polymer Electrolyte Membrane Fuel Cell system

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen; Jensen, Hans-Christian Becker

    , i.e. cathode and anode gas flows and temperature by using mass flow controllers and controlled heaters. Using this system the methanol reformer is characterized in its different operating points, both steady-state but also dynamically. Methanol steam reforming is a well known process, and provides...

  2. Torsionally mediated spin-rotation hyperfine splittings at moderate to high J values in methanol

    Science.gov (United States)

    Belov, S. P.; Golubiatnikov, G. Yu.; Lapinov, A. V.; Ilyushin, V. V.; Alekseev, E. A.; Mescheryakov, A. A.; Hougen, J. T.; Xu, Li-Hong

    2016-07-01

    This paper presents an explanation based on torsionally mediated proton-spin-overall-rotation interaction for the observation of doublet hyperfine splittings in some Lamb-dip sub-millimeter-wave transitions between ground-state torsion-rotation states of E symmetry in methanol. These unexpected doublet splittings, some as large as 70 kHz, were observed for rotational quantum numbers in the range of J = 13 to 34, and K = - 2 to +3. Because they increase nearly linearly with J for a given branch, we confined our search for an explanation to hyperfine operators containing one nuclear-spin angular momentum factor I and one overall-rotation angular momentum factor J (i.e., to spin-rotation operators) and ignored both spin-spin and spin-torsion operators, since they contain no rotational angular momentum operator. Furthermore, since traditional spin-rotation operators did not seem capable of explaining the observed splittings, we constructed totally symmetric "torsionally mediated spin-rotation operators" by multiplying the E-species spin-rotation operator by an E-species torsional-coordinate factor of the form e±niα. The resulting operator is capable of connecting the two components of a degenerate torsion-rotation E state. This has the effect of turning the hyperfine splitting pattern upside down for some nuclear-spin states, which leads to bottom-to-top and top-to-bottom hyperfine selection rules for some transitions, and thus to an explanation for the unexpectedly large observed hyperfine splittings. The constructed operator cannot contribute to hyperfine splittings in the A-species manifold because its matrix elements within the set of torsion-rotation A1 and A2 states are all zero. The theory developed here fits the observed large doublet splittings to a root-mean-square residual of less than 1 kHz and predicts unresolvable splittings for a number of transitions in which no doublet splitting was detected.

  3. Corrosion Behavior of Pure Cr, Ni, and Fe Exposed to Molten Salts at High Temperature

    Directory of Open Access Journals (Sweden)

    O. Sotelo-Mazón

    2014-01-01

    Full Text Available Corrosion resistance of pure Fe, Cr, and Ni materials exposed in NaVO3 molten salt at 700°C was evaluated in static air during 100 hours. The corrosion resistance was determined using potentiodynamic polarization, open circuit potential, and lineal polarization resistance. The conventional weight loss method (WLM was also used during 100 hours. The electrochemical results showed that Fe and Cr have a poor corrosion resistance, whereas pure Ni showed the best corrosion performance, which was supported by the passive layer of NiO formed on the metallic surface and the formation of Ni3V2O8 during the corrosion processes, which is a refractory compound with a higher melting point than that of NaVO3, which reduces the corrosivity of the molten salt. Also, the behavior of these materials was associated with the way in which their corresponding oxides were dissolved together with their type of corrosion attack. Through this study, it was confirmed that when materials suffer corrosion by a localized processes such as pitting, the WLM is not reliable, since a certain amount of corrosion products can be kept inside the pits. The corroded samples were analyzed through scanning electron microscopy.

  4. Formation Mechanism of Micropores on the Surface of Pure Aluminum Induced by High-Current Pulsed Electron Beam Irradiation

    Institute of Scientific and Technical Information of China (English)

    ZOU Yang; CAI Jie; WAN Ming-Zhen; LV Peng; GUAN Qing-Feng

    2011-01-01

    The mechanism of micropores formed on the surface of polycrystalline pure aluminum under high-current pulsed electron beam (HCPEB) irradiation is explained. It is discovered that dispersed micropores with sizes of 0.1-1μm on the irradiated surface of pure aluminum can be successfully fabricated after HCPEB irradiation. The dominant formation mechanism of the surface micropores should be attributed to the formation of supersaturation vacancies within the near surface during the HCPEB irradiation and the migration of vacancies along gra,in boundaries and/or dislocations towards the irradiated surface. It is expected that the HCPEB technique will become a new method for the rapid synthesis of surface porous materials.%The mechanism of micropores formed on the surface of polycrystalline pure aluminum under high-current pulsed electron beam (HCPEB) irradiation is explained.It is discovered that dispersed micropores with sizes of 0.1-1μm on the irradiated surface of pure aluminum can be successfully fabricated after HCPEB irradiation.The dominant formation mechanism of the surface micropores should be attributed to the formation of supersaturation vacancies within the near surface during the HCPEB irradiation and the migration of vacancies along grain boundaries and/or dislocations towards the irradiated surface.It is expected that the HCPEB technique will become a new method for the rapid synthesis of surface porous materials.High-current pulsed electron beams (HCPEBs)have attracted much attention in the field of material surface modification.[1-7] During the transient bombardment process a high energy (108-109 W·cm-2) is deposited only in a very thin layer (less than tens of micrometers) within a very short time (a few microseconds) and thereby causes ultrafast heating and cooling on the irradiated surface of materials.The dynamic stress fields induced in these processes can induce intense deformation on the material surface.

  5. An Analysis of Methanol and Hydrogen Production via High-Temperature Electrolysis Using the Sodium Cooled Advanced Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Shannon M. Bragg-Sitton; Richard D. Boardman; Robert S. Cherry; Wesley R. Deason; Michael G. McKellar

    2014-03-01

    Integration of an advanced, sodium-cooled fast spectrum reactor into nuclear hybrid energy system (NHES) architectures is the focus of the present study. A techno-economic evaluation of several conceptual system designs was performed for the integration of a sodium-cooled Advanced Fast Reactor (AFR) with the electric grid in conjunction with wind-generated electricity. Cases in which excess thermal and electrical energy would be reapportioned within an integrated energy system to a chemical plant are presented. The process applications evaluated include hydrogen production via high temperature steam electrolysis and methanol production via steam methane reforming to produce carbon monoxide and hydrogen which feed a methanol synthesis reactor. Three power cycles were considered for integration with the AFR, including subcritical and supercritical Rankine cycles and a modified supercritical carbon dioxide modified Brayton cycle. The thermal efficiencies of all of the modeled power conversions units were greater than 40%. A thermal efficiency of 42% was adopted in economic studies because two of the cycles either performed at that level or could potentially do so (subcritical Rankine and S-CO2 Brayton). Each of the evaluated hybrid architectures would be technically feasible but would demonstrate a different internal rate of return (IRR) as a function of multiple parameters; all evaluated configurations showed a positive IRR. As expected, integration of an AFR with a chemical plant increases the IRR when “must-take” wind-generated electricity is added to the energy system. Additional dynamic system analyses are recommended to draw detailed conclusions on the feasibility and economic benefits associated with AFR-hybrid energy system operation.

  6. Prediction of oxygen solubility in pure water and brines up to high temperatures and pressures

    Science.gov (United States)

    GENG, Ming; DUAN, Zhenhao

    2010-10-01

    A thermodynamic model is presented to calculate the oxygen solubility in pure water (273-600 K, 0-200 bar) and natural brines containing Na +, K +, Ca 2+, Mg 2+, Cl -, SO 42-, over a wide range of temperature, pressure and ionic strength with or close to experimental accuracy. This model is based on an accurate equation of state to calculate vapor phase chemical potential and a specific particle interaction model for liquid phase chemical potential. With this approach, the model can not only reproduce the existing experimental data, but also extrapolate beyond the data range from simple aqueous salt system to complicated brine systems including seawater. Compared with previous models, this model covers much wider temperature and pressure space in variable composition brine systems. A program for this model can be downloaded from the website: http://www.geochem-model.org.

  7. Method for making methanol

    Science.gov (United States)

    Mednick, R. Lawrence; Blum, David B.

    1986-01-01

    Methanol is made in a liquid-phase methanol reactor by entraining a methanol-forming catalyst in an inert liquid and contacting said entrained catalyst with a synthesis gas comprising hydrogen and carbon monoxide.

  8. Process Design and Economics for the Conversion of Lignocellulosic Biomass to High Octane Gasoline: Thermochemical Research Pathway with Indirect Gasification and Methanol Intermediate

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Eric [National Renewable Energy Lab. (NREL), Golden, CO (United States); Talmadge, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dutta, Abhijit [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hensley, Jesse [National Renewable Energy Lab. (NREL), Golden, CO (United States); Schaidle, Josh [National Renewable Energy Lab. (NREL), Golden, CO (United States); Biddy, Mary J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Humbird, David [DWH Process Consulting, Denver, CO (United States); Snowden-Swan, Lesley J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ross, Jeff [Harris Group, Inc., Seattle, WA (United States); Sexton, Danielle [Harris Group, Inc., Seattle, WA (United States); Yap, Raymond [Harris Group, Inc., Seattle, WA (United States); Lukas, John [Harris Group, Inc., Seattle, WA (United States)

    2015-03-01

    The U.S. Department of Energy (DOE) promotes research for enabling cost-competitive liquid fuels production from lignocellulosic biomass feedstocks. The research is geared to advance the state of technology (SOT) of biomass feedstock supply and logistics, conversion, and overall system sustainability. As part of their involvement in this program, the National Renewable Energy Laboratory (NREL) and the Pacific Northwest National Laboratory (PNNL) investigate the economics of conversion pathways through the development of conceptual biorefinery process models. This report describes in detail one potential conversion process for the production of high octane gasoline blendstock via indirect liquefaction (IDL). The steps involve the conversion of biomass to syngas via indirect gasification followed by gas cleanup and catalytic syngas conversion to a methanol intermediate; methanol is then further catalytically converted to high octane hydrocarbons. The conversion process model leverages technologies previously advanced by research funded by the Bioenergy Technologies Office (BETO) and demonstrated in 2012 with the production of mixed alcohols from biomass. Biomass-derived syngas cleanup via tar and hydrocarbons reforming was one of the key technology advancements as part of that research. The process described in this report evaluates a new technology area with downstream utilization of clean biomass-syngas for the production of high octane hydrocarbon products through a methanol intermediate, i.e., dehydration of methanol to dimethyl ether (DME) which subsequently undergoes homologation to high octane hydrocarbon products.

  9. Strawberry puree processed by thermal, high pressure, or power ultrasound: Process energy requirements and quality modeling during storage.

    Science.gov (United States)

    Sulaiman, Alifdalino; Farid, Mohammed; Silva, Filipa Vm

    2017-06-01

    Strawberry puree was processed for 15 min using thermal (65 ℃), high-pressure processing (600 MPa, 48 ℃), and ultrasound (24 kHz, 1.3 W/g, 33 ℃). These conditions were selected based on similar polyphenoloxidase inactivation (11%-18%). The specific energies required for the above-mentioned thermal, high-pressure processing, and power ultrasound processes were 240, 291, and 1233 kJ/kg, respectively. Then, the processed strawberry was stored at 3 ℃ and room temperature for 30 days. The constant pH (3.38±0.03) and soluble solids content (9.03 ± 0.25°Brix) during storage indicated a microbiological stability. Polyphenoloxidase did not reactivate during storage. The high-pressure processing and ultrasound treatments retained the antioxidant activity (70%-74%) better than the thermal process (60%), and high-pressure processing was the best treatment after 30 days of ambient storage to preserve antioxidant activity. Puree treated with ultrasound presented more color retention after processing and after ambient storage than the other preservation methods. For the three treatments, the changes of antioxidant activity and total color difference during storage were described by the fractional conversion model with rate constants k ranging between 0.03-0.09 and 0.06-0.22 day (- 1), respectively. In resume, high-pressure processing and thermal processes required much less energy than ultrasound for the same polyphenoloxidase inactivation in strawberry. While high-pressure processing retained better the antioxidant activity of the strawberry puree during storage, the ultrasound treatment was better in terms of color retention.

  10. High electrocatalytic performance of nitrogen-doped carbon nanofiber-supported nickel oxide nanocomposite for methanol oxidation in alkaline medium

    Science.gov (United States)

    Al-Enizi, Abdullah M.; Elzatahry, Ahmed A.; Abdullah, Aboubakr M.; Vinu, Ajayan; Iwai, Hideo; Al-Deyab, Salem S.

    2017-04-01

    Nitrogen-Doped Carbon Nanofiber (N-CNF)-supported NiO composite was prepared by electrospinning a sol-gel mixture of graphene and polyaniline (PANi) with aqueous solutions of Polyvinylpyrrolidone (PVP) followed by a high-temperature annealing process. The electrospun was stabilized for 2 h at 280 °C, carbonized for 5 h at 1200 °C then loaded by 10% NiO. The electrocatalytic activities of the produced nanocomposite have been studied using cyclic voltammetry, and chronoamperometry. Also, N-CNF was characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), surface area (BET), X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), and scanning-electron microscopy (SEM). The obtained N-doped carbon nanofiber was found to have a nitrogen content of 2.6 atomic% with a diameter range of (140-160) nm, and a surface area (393.3 m2 g-1). In addition, it showed a high electrocatalytic behavior towards methanol oxidation reaction in alkaline medium and high stability and resistivity to the adsorption of intermediates.

  11. Induction heating pure vapor source of high temperature melting point materials on electron cyclotron resonance ion source.

    Science.gov (United States)

    Kutsumi, Osamu; Kato, Yushi; Matsui, Yuuki; Kitagawa, Atsushi; Muramatsu, Masayuki; Uchida, Takashi; Yoshida, Yoshikazu; Sato, Fuminobu; Iida, Toshiyuki

    2010-02-01

    Multicharged ions that are needed are produced from solid pure material with high melting point in an electron cyclotron resonance ion source. We develop an evaporator by using induction heating (IH) with multilayer induction coil, which is made from bare molybdenum or tungsten wire without water cooling and surrounding the pure vaporized material. We optimize the shapes of induction coil and vaporized materials and operation of rf power supply. We conduct experiment to investigate the reproducibility and stability in the operation and heating efficiency. IH evaporator produces pure material vapor because materials directly heated by eddy currents have no contact with insulated materials, which are usually impurity gas sources. The power and the frequency of the induction currents range from 100 to 900 W and from 48 to 23 kHz, respectively. The working pressure is about 10(-4)-10(-3) Pa. We measure the temperature of the vaporized materials with different shapes, and compare them with the result of modeling. We estimate the efficiency of the IH vapor source. We are aiming at the evaporator's higher melting point material than that of iron.

  12. Pure zinc sulfide quantum dot as highly selective luminescent probe for determination of hazardous cyanide ion.

    Science.gov (United States)

    Shamsipur, Mojtaba; Rajabi, Hamid Reza

    2014-03-01

    A rapid and simple fluorescence method is presented for selective and sensitive determination of hazardous cyanide ion in aqueous solution based on functionalized zinc sulfide (ZnS) quantum dot (QD) as luminescent prob. The ultra-small ZnS QDs were synthesized using a chemical co-precipitation method in the presence of 2-mercaptoethanol (ME) as an efficient capping agent. The prepared pure ZnS QDs was applied as an optical sensor for determination of cyanide ions in aqueous solutions. ZnS nanoparticles have exhibited a strong fluorescent emission at about 424 nm. The fluorescence intensity of QDs is linearly proportional to the cyanide ion concentration in the range 2.44×10(-6) to 2.59×10(-5)M with a detection limit of 1.70×10(-7)M at pH11. The designed fluorescent sensor possesses remarkable selectivity for cyanide ion over other anions such as Cl(-), Br(-), F(-), I(-), IO3(-), ClO4(-), BrO3(-), CO3(2-), NO2(-), NO3(-), SO4(2-), S2O4(2-), C2O4(2-), SCN(-), N3(-), citrate and tartarate with negligible influences on the cyanide detection by fluorescence spectroscopy. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Rare earth effects on high temperature oxidation of pure nickel at 1000 ℃

    Institute of Scientific and Technical Information of China (English)

    JIN Huiming; ZHANG Jianfeng; YAN Kun; GONG Zexiang

    2004-01-01

    Isothermal and cyclic oxidation behaviors of pure and yttrium-implanted nickel were studied at 1000 ℃ in air.SEM and TEM were used to examine the oxide scales formed on nickel substrate.It was found that Y-implantation greatly improved the anti-oxidation ability of nickel both in isothermal and cyclic oxidizing experiments.Acoustic emission(AE)technique was used to study the size and number distribution of defects at the oxide/metal interface.Laser Raman microscopy was also used to study the stress status of oxide scales formed on nickel with and without yttrium.The main reason for the improvement in anti-oxidation and adhesion of oxide scale was that Yimplantation greatly reduced the grain size of NiO and lowered the compressive stress within the scale.In the meantime,Y-implantation inhibited ion diffusion rate in the oxide scale and reduced the size and number of interfacial defects,hence remarkably enhanced the adhesion of protective NiO oxide scale formed on nickel substrate.

  14. Highly conductive and pure gold nanostructures grown by electron beam induced deposition

    Science.gov (United States)

    Shawrav, Mostafa M.; Taus, Philipp; Wanzenboeck, Heinz D.; Schinnerl, M.; Stöger-Pollach, M.; Schwarz, S.; Steiger-Thirsfeld, A.; Bertagnolli, Emmerich

    2016-09-01

    This work introduces an additive direct-write nanofabrication technique for producing extremely conductive gold nanostructures from a commercial metalorganic precursor. Gold content of 91 atomic % (at. %) was achieved by using water as an oxidative enhancer during direct-write deposition. A model was developed based on the deposition rate and the chemical composition, and it explains the surface processes that lead to the increases in gold purity and deposition yield. Co-injection of an oxidative enhancer enabled Focused Electron Beam Induced Deposition (FEBID)—a maskless, resistless deposition method for three dimensional (3D) nanostructures—to directly yield pure gold in a single process step, without post-deposition purification. Gold nanowires displayed resistivity down to 8.8 μΩ cm. This is the highest conductivity achieved so far from FEBID and it opens the possibility of applications in nanoelectronics, such as direct-write contacts to nanomaterials. The increased gold deposition yield and the ultralow carbon level will facilitate future applications such as the fabrication of 3D nanostructures in nanoplasmonics and biomolecule immobilization.

  15. Achieving High Strength Joint of Pure Copper Via Laser-Cold Metal Transfer Arc Hybrid Welding

    Science.gov (United States)

    Chen, Yulong; Chen, Cong; Gao, Ming; Zeng, Xiaoyan

    2016-06-01

    Fiber laser-cold metal transfer arc hybrid welding of pure copper was studied. Weld porosity was tested by X-ray nondestructive testing. Microstructure and fracture features were observed by scanning electron microscopy. Mechanical properties were evaluated by cross weld tensile test. Full penetrated and continuous welds were obtained by hybrid welding once the laser power reached 2 kW, while they could not be obtained by laser welding alone, even though the laser power reached 5 kW. The ultimate tensile strength (UTS), the yield strength (YS), and the elongation of the best hybrid weld material were up to 227, 201 MPa, and 21.5 pct, respectively. The joint efficiencies in UTS and YS of hybrid weld were up to 84 and 80 pct of the BM, respectively. The fracture location changes from the fusion zone to the heat-affected zone with the increase of laser power. Besides, the mechanisms of process stability and porosity suppression were clarified by laser-arc interaction and pool behavior. The strengthening mechanism was discussed by microstructure characteristics.

  16. Evolution of laparoscopic surgery in a high volume hepatobiliary unit: 150 consecutive pure laparoscopic hepatectomies.

    Science.gov (United States)

    López-Ben, Santiago; Ranea, Alejandro; Albiol, M Teresa; Falgueras, Laia; Castro, Ernesto; Casellas, Margarida; Codina-Barreras, Antoni; Figueras, Joan

    2017-05-01

    Compared to other surgical areas, laparoscopic liver resection (LLR) has not been widely implemented and currently less than 20% of hepatectomies are performed laparoscopically worldwide. The aim of our study was to evaluate the feasibility, and the ratio of implementation of LLR in our department. We analyzed a prospectively maintained database of 749 liver resections performed during the last 10-year period in a single centre. A total of 150 (20%) consecutive pure LLR were performed between 2005 and 2015. In 87% of patients the indication was the presence ofprimary or metastatic liver malignancy. We performed 30 major hepatectomies (20%) and (80%) were minor resections, performed in all liver segments. Twelve patients were operated twice and 2 patients underwent a third LLR. The proportion of LLR increased from 12% in 2011 to 62% in the last year. Conversion rate was 9%. Overall morbidity rate was 36% but only one third were classified as severe. The 90-day mortality rate was 1%. Median hospital stay was 4 days and the rate of readmissions was 6%. The implementation of LLR has been fast with morbidity and mortality comparable to other published series. In the last 2 years more than half of the hepatectomies are performed laparoscopically in our centre. Copyright © 2017 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

  17. Design and stabilisation of a high area iron molybdate surface for the selective oxidation of methanol to formaldehyde.

    Science.gov (United States)

    Chapman, Stephanie; Brookes, Catherine; Bowker, Michael; Gibson, Emma K; Wells, Peter P

    2016-07-04

    The performance of Mo-enriched, bulk ferric molybdate, employed commercially for the industrially important reaction of the selective oxidation of methanol to formaldehyde, is limited by a low surface area, typically 5-8 m(2) g(-1). Recent advances in the understanding of the iron molybdate catalyst have focused on the study of MoOx@Fe2O3 (MoOx shell, Fe2O3 core) systems, where only a few overlayers of Mo are present on the surface. This method of preparing MoOx@Fe2O3 catalysts was shown to support an iron molybdate surface of higher surface area than the industrially-favoured bulk phase. In this research, a MoOx@Fe2O3 catalyst of even higher surface area was stabilised by modifying a haematite support containing 5 wt% Al dopant. The addition of Al was an important factor for stabilising the haematite surface area and resulted in an iron molybdate surface area of ∼35 m(2) g(-1), around a 5 fold increase on the bulk catalyst. XPS confirmed Mo surface-enrichment, whilst Mo XANES resolved an amorphous MoOx surface monolayer supported on a sublayer of Fe2(MoO4)3 that became increasingly extensive with initial Mo surface loading. The high surface area MoOx@Fe2O3 catalyst proved amenable to bulk characterisation techniques; contributions from Fe2(MoO4)3 were detectable by Raman, XAFS, ATR-IR and XRD spectroscopies. The temperature-programmed pulsed flow reaction of methanol showed that this novel, high surface area catalyst (3ML-HSA) outperformed the undoped analogue (3ML-ISA), and a peak yield of 94% formaldehyde was obtained at ∼40 °C below that for the bulk Fe2(MoO4)3 phase. This work demonstrates how core-shell, multi-component oxides offer new routes for improving catalytic performance and understanding catalytic activity.

  18. Esterification of oleic acid with methanol by immobilized lipase on wrinkled silica nanoparticles with highly ordered, radially oriented mesochannels.

    Science.gov (United States)

    Pang, Jinli; Zhou, Guowei; Liu, Ruirui; Li, Tianduo

    2016-02-01

    Mesoporous silica nanoparticles with a wrinkled structure (wrinkled silica nanoparticles, WSNs) having highly ordered, radially oriented mesochannels were synthesized by a solvothermal method. The method used a mixture of cyclohexane, ethanol, and water as solvent, tetraethoxysilane (TEOS) as source of inorganic silica, ammonium hydroxide as hydrolysis additive, cetyltrimethylammonium bromide (CTAB) as surfactant, and polyvinylpyrrolidone (PVP) as stabilizing agent of particle growth. Particle size (240nm to 540nm), specific surface areas (490m(2)g(-1) to 634m(2)g(-1)), surface morphology (radial wrinkled structures), and pore structure (radially oriented mesochannels) of WSN samples were varied using different molar ratios of CTAB to PVP. Using synthesized WSN samples with radially oriented mesochannels as support, we prepared immobilized Candida rugosa lipase (CRL) as a new biocatalyst for biodiesel production through the esterification of oleic acid with methanol. These results suggest that WSNs with highly ordered, radially oriented mesochannels have promising applications in biocatalysis, with the highest oleic acid conversion rate of about 86.4% under the optimum conditions.

  19. Highly Efficient and Exceptionally Durable CO2 Photoreduction to Methanol over Freestanding Defective Single-Unit-Cell Bismuth Vanadate Layers.

    Science.gov (United States)

    Gao, Shan; Gu, Bingchuan; Jiao, Xingchen; Sun, Yongfu; Zu, Xiaolong; Yang, Fan; Zhu, Wenguang; Wang, Chengming; Feng, Zimou; Ye, Bangjiao; Xie, Yi

    2017-03-08

    Unearthing an ideal model for disclosing the role of defect sites in solar CO2 reduction remains a great challenge. Here, freestanding gram-scale single-unit-cell o-BiVO4 layers are successfully synthesized for the first time. Positron annihilation spectrometry and X-ray fluorescence unveil their distinct vanadium vacancy concentrations. Density functional calculations reveal that the introduction of vanadium vacancies brings a new defect level and higher hole concentration near Fermi level, resulting in increased photoabsorption and superior electronic conductivity. The higher surface photovoltage intensity of single-unit-cell o-BiVO4 layers with rich vanadium vacancies ensures their higher carriers separation efficiency, further confirmed by the increased carriers lifetime from 74.5 to 143.6 ns revealed by time-resolved fluorescence emission decay spectra. As a result, single-unit-cell o-BiVO4 layers with rich vanadium vacancies exhibit a high methanol formation rate up to 398.3 μmol g(-1) h(-1) and an apparent quantum efficiency of 5.96% at 350 nm, much larger than that of single-unit-cell o-BiVO4 layers with poor vanadium vacancies, and also the former's catalytic activity proceeds without deactivation even after 96 h. This highly efficient and spectrally stable CO2 photoconversion performances hold great promise for practical implementation of solar fuel production.

  20. Experimental Characterization of the Poisoning Effects of Methanol-Based Reformate Impurities on a PBI-Based High Temperature PEM Fuel Cell

    Directory of Open Access Journals (Sweden)

    Samuel Simon Araya

    2012-10-01

    Full Text Available In this work the effects of reformate gas impurities on a H3PO4-doped polybenzimidazole (PBI membrane-based high temperature proton exchange membrane fuel cell (HT-PEMFC are studied. A unit cell assembly with a BASF Celtec®-P2100 high temperature membrane electrode assembly (MEA of 45 cm2 active surface area is investigated by means of impedance spectroscopy. The concentrations in the anode feed gas of all impurities, unconverted methanol-water vapor mixture, CO and CO2 were varied along with current density according to a multilevel factorial design of experiments. Results show that all the impurities degrade the performance, with CO being the most degrading agent and CO2 the least. The factorial analysis shows that there is interdependence among the effects of the different factors considered. This interdependence suggests, for example, that tolerances to concentrations of CO above 2% may be compromised by the presence in the anode feed of CO2. Methanol has a poisoning effect on the fuel cell at all the tested feed ratios, and the performance drop is found to be proportional to the amount of methanol in feed gas. The effects are more pronounced when other impurities are also present in the feed gas, especially at higher methanol concentrations.

  1. Monodisperse Pt Nanoparticles Assembled on Reduced Graphene Oxide: Highly Efficient and Reusable Catalyst for Methanol Oxidation and Dehydrocoupling of Dimethylamine-Borane (DMAB).

    Science.gov (United States)

    Yildiz, Yunus; Erken, Esma; Pamuk, Handan; Sert, Hakan; Sen, Fatih

    2016-06-01

    Herein, monodisperse platinum (0) nanocatalyst assembled on reduced graphene oxide (Pt(0)@RGO) was easily and reproducibly prepared by the double solvent reduction method at room temperature. Pt(0)@RGO was characterized by X-ray diffraction (XRD), X-ray photoelectron microscopy (XPS) and transmission electron microscopy (TEM) measurements that verify the formation of monodisperse Pt (0) nanoparticles on RGO. The catalytic and electrocatalytic performances of Pt(0) @ RGO in terms of activity, isolability and reusability were investigated for both methanol oxidation and the dehydrocoupling of dimethylamine-borane (DMAB) in which Pt(0)@RGO was found to be highly active and reusable heterogeneous catalyst even at room temperature. The prepared nanoparticles can also electrocatalyze methanol oxidation with very high electrochemical activities (5.64 A/cm2 at 0.58 V for methanol). The activation energy (Ea), activation enthalpy (ΔH#), and activation entropy (ΔS#) for DMAB dehydrogenation were calculated to be 59.33 kJ mol(-1), 56.79 kJ mol(-1) and -151.68 J mol(-1) K(-1), respectively. The exceptional stability of new Pt(0) @ RGO nanoparticles towards agglomeration, leaching and CO poisoning allow these particles to be recycled and reused in the catalysis of DMAB dehydrogenation and methanol oxidation. After four subsequent reaction and recovery cycles, Pt(0) @ RGO retained ≥ 75% activity towards the complete dehydrogenation of DMAB.

  2. High-Pressure Autoignition of Binary Blends of Methanol and Dimethyl Ether

    OpenAIRE

    Wang, Hongfu; Weber, Bryan W.; Fang, Ruozhou; Sung, Chih-Jen

    2017-01-01

    Reactivity Controlled Compression Ignition (RCCI) is a new advanced engine concept that uses a dual fuel mode of operation to achieve significant improvements in fuel economy and emissions output. The fuels that are typically used in this mode include a low- and a high-reactivity fuel in varying proportions to control ignition timing. As such, understanding the interaction effects during autoignition of binary fuel blends is critical to optimizing these RCCI engines. In this work, we measure ...

  3. Preparation, characterization, and high performance of RuSe/C for direct methanol fuel cells

    Science.gov (United States)

    Serov, Alexey Alexandrovich; Min, Myoungki; Chai, Geunseok; Han, Sangil; Kang, Soonki; Kwak, Chan

    RuSe/C catalysts prepared by different methods have been tested for oxygen reduction and the results analyzed based on the active species and particle size distribution. Inorganic precursor methods exhibit higher catalytic performance than the carbonyl method. Selenious acid is an excellent inorganic precursor. X-ray photoelectron spectra indicate that selenium in a high oxidation state is more active than that with zero valence. The effect of operating conditions is analyzed for catalysts prepared by the inorganic precursor method. The optimum heat-treatment temperature for both active phase formation and particle size distribution is 300 °C. A performance of 62 mW cm -2 at 80 °C is obtained using 80 wt.% RuSe/C in the cathode.

  4. A HIGH PERFORMANCE FULLY DIFFERENTIAL PURE CURRENT MODE OPERATIONAL AMPLIFIER AND ITS APPLICATIONS

    Directory of Open Access Journals (Sweden)

    SEYED JAVAD AZHARI

    2012-08-01

    Full Text Available In this paper a novel high performance all current-mode fully-differential (FD Current mode Operational Amplifier (COA in BIPOLAR technology is presented. The unique true current mode simple structure grants the proposed COA the largest yet reported unity gain frequency while providing low voltage low power operation. Benefiting from some novel ideas, it also exhibits high gain, high common mode rejection ratio (CMRR, high power supply rejection ratio (PSRR, high output impedance, low input impedance and most importantly high current drive capability. Its most important parameters are derived and its performance is proved by PSPICE simulations using 0.8 μm BICMOS process parameters at supply voltage of ±1.2V indicating the values of 82.4 dB,52.3º, 31.5 Ω, 31.78 MΩ, 179.2 dB, 2 mW and 698 MHz for gain, phase margin, input impedance, output impedance, CMRR, power and unity gain frequency respectively. Its CMRR also shows very high frequency of 2.64 GHz at zero dB. Its very high PSRR+/PSRR- of 182 dB/196 dB makes the proposed COA a highly suitable block in Mixed-Mode (SOC chips. Most favourably it can deliver up to ±1.5 mA yielding a high current drive capability exceeding 25. To demonstrate the performance of the proposed COA, it is used to realize a constant bandwidth voltage amplifier and a high performance Rm amplifier.

  5. Comparison of UV and high-energy ion irradiation of methanol:ammonia ice

    CERN Document Server

    Caro, G M Munoz; Boduch, P; Rothard, H; Domaracka, A; Jimenez-Escobar, A

    2014-01-01

    The main goal of this work is to compare the effects induced in ices of astrophysical relevance by high-energy ions, simulating cosmic rays, and by vacuum ultraviolet (UV) photons. This comparison relies on in situ infrared spectroscopy of irradiated CH3OH:NH3 ice. Swift heavy ions were provided by the GANIL accelerator. The source of UV was a microwave-stimulated hydrogen flow discharge lamp. The deposited energy doses were similar for ion beams and UV photons to allow a direct comparison. A variety of organic species was detected during irradiation and later during ice warm-up. These products are common to ion and UV irradiation for doses up to a few tens of eV per molecule. Only the relative abundance of the CO product, after ice irradiation, was clearly higher in the ion irradiation experiments. For some ice mixture compositions, the irradiation products formed depend only weakly on the type of irradiation, swift heavy ions, or UV photons. This simplifies the chemical modeling of energetic ice processing ...

  6. Reactor target from metal chromium for "pure" high-intensive artificial neutrino source

    Science.gov (United States)

    Gavrin, V. N.; Kozlova, Yu. P.; Veretenkin, E. P.; Logachev, A. V.; Logacheva, A. I.; Lednev, I. S.; Okunkova, A. A.

    2017-01-01

    The paper presents the first results of development of manufacturing technology of metallic chromium targets from highly enriched isotope 50Cr for irradiation in a high flux nuclear reactor to obtain a compact high intensity neutrino source with low content of radionuclide impurities and minimum losses of enriched isotope. The main technological stages are the hydrolysis of chromyl fluoride, the electrochemical reduction of metallic chromium, the hot isostatic pressing of chromium powder and the electrical discharge machining of chromium bars. The technological stages of hot isostatic pressing of chromium powder and of electrical discharge machining of Cr rods have been tested.

  7. Preparation of Highly Pure Vanadyl Sulfate from Sulfate Solutions Containing Impurities of Iron and Aluminum by Solvent Extraction Using EHEHPA

    Directory of Open Access Journals (Sweden)

    Dan Li

    2017-03-01

    Full Text Available The preparation of highly pure vanadyl sulfate from sulfate solutions containing impurities of iron and aluminumwas investigated by solvent extraction with 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester (EHEHPA and tri-n-butyl phosphate (TBP as the phase modifier. The extraction and stripping conditions of vanadium (IV and its separation from iron and aluminum were optimized. Under the optimal extraction conditions, the extraction of vanadium (IV and iron were 68% and 53%, respectively, while only 2% aluminum was extracted in a single contact, suggesting good separation of vanadium (IV from aluminum. Sulfuric acid solution was used for the stripping. Nearly 100% vanadium (IV and 95% aluminum were stripped, while only 10% iron was stripped under the optimal stripping conditions in a single contact, suggesting good separation of vanadium (IV from iron. After five stages of extraction and stripping, highly pure vanadyl sulfate containing 76.5 g/L V (IV with the impurities of 12 mg/L Fe and 10 mg/L Al was obtained, which is suitable for the electrolyte of a vanadium redox flow battery. Organic solution was well regenerated after stripping by oxalic acid solution to remove the remaining iron. The mechanism of vanadium (IV extraction using EHEHPA was also discussed based on the Fourier transform infrared spectroscopy (FT-IR analysis.

  8. Design and synthesis of palladium/graphitic carbon nitride/carbon black hybrids as high-performance catalysts for formic acid and methanol electrooxidation

    Science.gov (United States)

    Qian, Huayu; Huang, Huajie; Wang, Xin

    2015-02-01

    Here we report a facile two-step method to synthesize high-performance palladium/graphitic carbon nitride/carbon black (Pd/g-C3N4/carbon black) hybrids for electrooxidizing formic acid and methanol. The coating of g-C3N4 on carbon black surface is realized by a low-temperature heating treatment, followed by the uniform deposition of palladium nanoparticles (Pd NPs) via a wet chemistry route. Owning to the significant synergistic effects of the individual components, the preferred Pd/g-C3N4/carbon black electrocatalyst exhibits exceptional forward peak current densities as high as 2155 and 1720 mA mg-1Pd for formic acid oxidation in acid media and methanol oxidation in alkaline media, respectively, far outperforming the commercial Pd-C catalyst. The catalyst also shows reliable stability, demonstrating that the newly-designed hybrids have great promise in constructing high-performance portable fuel cell systems.

  9. Real condition high throughput screening of Cu/ZnO/Al{sub 2}O{sub 3}. Catalysts for methanol synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Baltes, C.; Vukojevic, S.; Schueth, F. [Max-Planck-Institut fuer Kohlenforschung, Muehlheim an der Ruhr (Germany)

    2006-07-01

    Ternary Cu/ZnO/Al{sub 2}O{sub 3} catalysts were systematically prepared via the co-precipitation route under strict control of parameters such as pH, precipitation temperature and calcination temperature. All catalysts were tested with respect to their methanol activity in a 49-fold multitubular high-throughput experimentation setup under conditions similar to the commercial methanol production route, using a syngas mixture of CO, CO{sub 2} and H{sub 2}. Statistically representative catalysts were chosen for more detailed structure and morphology analysis in order to study correlations between the catalyst ''preparation history'' and the methanol productivity. The highest catalyst performance was observed for catalysts obtained in the pH range from 6 to 8 at 70 C. XRD measurements allowed the ''grouping'' of catalysts based on their composition. It was found that a group of best-performance catalysts exhibited the characteristic XRD pattern of non-calcined Cu/Zn hydroxycarbonate residues, leading to the assumption that carbonate species in the final catalyst structure may enhance its productivity. Further investigations of these hydroxycarbonate containing catalysts gave more detailed insights into the dynamic aging process and its influence on the catalytic performance. Highest methanol activity was observed for catalysts aged between 20 and 60 minutes after an initial phase formation time. The optimum calcination temperature was found to be in the range from 250 to 300 C. Under these conditions the resulting Cu/Zn/Al hydroxycarbonates remained stable. Additionally, the syngas feed composition was varied under reaction conditions and correlated to catalytic activities. Highest methanol productivity over Cu/ZnO/Al{sub 2}O{sub 3} catalysts was observed for the following gas concentrations; H{sub 2}: 50-60 %, CO: 30-40 % and CO{sub 2}: 5-10 % at 4.5 MPa and 245 C. (orig.)

  10. High rate capability pure Sn-based nano-architectured electrode assembly for rechargeable lithium batteries

    Energy Technology Data Exchange (ETDEWEB)

    Bazin, L.; Mitra, S.; Taberna, P.L.; Gressier, M.; Menu, M.J.; Barnabe, A.; Simon, P. [CIRIMAT-UMR 5085- Universite Paul Sabatier, route de Narbonne, 31062 Toulouse Cedex 4 (France); Poizot, P.; Tarascon, J.-M. [LRCS-UMR 6007-Universite de Picardie Jules Verne, 33 rue Saint-Leu, 80039 Amiens (France)

    2009-03-15

    New high surface area nano-architectured copper current collectors have been designed based on simple electrodeposition method. The nano-architectured electrode design not only increases the effective surface area of the electrode but it is also very suitable for sustaining the mechanical and structural strain during electrochemical reaction. In this work, a nano-architectured Sn anode for Li-ion battery, based on Li-Sn alloying reaction, delivers very high cycle life and good power performance compared to planar tin films. This electrode could be successfully used in the field of 3D microbatteries. (author)

  11. Investigation into high-frequency-vibration assisted micro-blanking of pure copper foils

    Directory of Open Access Journals (Sweden)

    Wang Chunju

    2015-01-01

    Full Text Available The difficulties encountered during the manufacture of microparts are often associated with size effects relating to material, process and tooling. Utilizing acoustoplastic softening, achieved through a high-frequency vibration assisted micro-blanking process, was introduced to improve the surface finish in micro-blanking. A frequency of 1.0 kHz was chosen to activate the longitudinal vibration mode of the horn tip, using a piezoelectric actuator. A square hole with dimensions of 0.5 mm × 0.5 mm was made, successfully, from a commercial rolled T2 copper foil with 100 μm in thickness. It was found that the maximum blanking force could be reduced by 5% through utilizing the high-frequency vibration. Proportion of the smooth, burnished area in the cut cross-section increases with an increase of the plasticity to fracture, under the high-frequency vibration, which suggests that the vibration introduced is helpful for inhibiting evolution of the crack due to its acoustoplastic softening effect. During blanking, roughness of the burnished surface could be reduced by increasing the vibration amplitude of the punch, which played a role as surface polishing. The results obtained suggest that the high-frequency vibration can be adopted in micro-blanking in order to improve quality of the microparts.

  12. A critical examination of pure tantalum processed by high-pressure torsion

    Energy Technology Data Exchange (ETDEWEB)

    Maury, Nicolas [École Nationale Supérieure des Ingénieurs en Arts Chimiques et Technologiques (ENSIACET), National Polytechnic Institute of Toulouse (INPT), 31077 Toulouse Cedex 04 (France); Zhang, Nian Xian; Huang, Yi [Materials Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ (United Kingdom); Zhilyaev, Alexander P. [Institute for Metals Superplasticity Problems, Russian Academy of Sciences, 39 Khalturina, 450001 Ufa (Russian Federation); Research Laboratory for Mechanics of New Nanomaterials, St. Petersburg State Polytechnical University, St. Petersburg 195251 (Russian Federation); Langdon, Terence G., E-mail: langdon@usc.edu [Materials Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ (United Kingdom); Departments of Aerospace & Mechanical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089-1453 (United States)

    2015-06-25

    Tantalum, a common refractory metal with body-centred cubic (BCC) crystalline structure, was processed by high-pressure torsion (HPT) at room temperature through different numbers of rotations. Significant grain refinement and high strength were achieved with a reduction in grain size from ∼60 μm to ∼160 nm and an increase in strength from ∼200 to >1300 MPa. Hardness measurements revealed a high level of homogeneity after 10 turns of HPT but the hardness after 10 turns was slightly lower than after 5 turns indicating the occurrence of some recovery. Tensile testing at a strain rate of 1.0×10{sup −3} s{sup −1} gave high strengths of ∼1200 MPa but little or no ductility after processing through 1, 5 and 10 turns. The introduction of a short-term (15 min) anneal immediately after HPT processing led to significant ductility in all samples and a reasonable level of strength at ∼800 MPa.

  13. Studies of methanol maser rings

    CERN Document Server

    Bartkiewicz, A; van Langevelde, H J; De Buizer, J M; Pihlström, Y

    2011-01-01

    We present the results of studies of a new class of 6.7 GHz methanol maser sources with a ring-like emission structure discovered recently with the EVN. We have used the VLA to search for water masers at 22 GHz and radio continuum at 8.4 GHz towards a sample of high-mass star forming regions showing a ring-like distribution of methanol maser spots. Using the Gemini telescopes we found mid-infrared (MIR) counterparts of five methanol rings with a resolution of 0."15. The centres of methanol maser rings are located within, typically, only 0."2 of the MIR emission peak, implying their physical relation with a central star. These results strongly support a scenario wherein the ring-like structures appear at the very early stage of massive star formation before either water-maser outflows or H II regions are seen.

  14. Dual template synthesis of a highly mesoporous SSZ-13 zeolite with improved stability in the methanol-to-olefins reaction

    OpenAIRE

    Wu, Leilei; Degirmenci, Volkan; Magusin, Pieter; Szyja, Bartlomiej M; Hensen, Emiel J.M.

    2012-01-01

    The dual template synthesis of zeolite SSZ-13 by use of trimethyl-adamantanammonium hydroxide and a diquaternary-ammonium mesoporogen induces considerable mesoporosity without impeding zeolite microporosity. The strongly improved accessibility of Brønsted sites in mesoporous SSZ-13 increases its stability during application as an acid catalyst in the methanol-to-olefins reaction.

  15. Dual template synthesis of a highly mesoporous SSZ-13 zeolite with improved stability in the methanol-to-olefins reaction.

    Science.gov (United States)

    Wu, Leilei; Degirmenci, Volkan; Magusin, Pieter C M M; Szyja, Bartłomiej M; Hensen, Emiel J M

    2012-10-04

    The dual template synthesis of zeolite SSZ-13 by use of trimethyl-adamantanammonium hydroxide and a diquaternary-ammonium mesoporogen induces considerable mesoporosity without impeding zeolite microporosity. The strongly improved accessibility of Brønsted sites in mesoporous SSZ-13 increases its stability during application as an acid catalyst in the methanol-to-olefins reaction.

  16. Double-beta decay investigation with highly pure enriched {sup 82}Se for the LUCIFER experiment

    Energy Technology Data Exchange (ETDEWEB)

    Beeman, J.W. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Bellini, F.; Casali, N.; Ferroni, F.; Piperno, G. [Sapienza Universita di Roma, Dipartimento di Fisica, Rome (Italy); INFN, Sezione di Roma, Rome (Italy); Benetti, P. [Universita di Pavia, Dipartimento di Chimica, Pavia (Italy); INFN, Sezione di Pavia, Pavia (Italy); Cardani, L. [Sapienza Universita di Roma, Dipartimento di Fisica, Rome (Italy); Princeton University, Physics Department, Princeton, NJ (United States); Chiesa, D.; Clemenza, M.; Gironi, L.; Maino, M. [Universita di Milano-Bicocca, Dipartimento di Fisica, Milan (Italy); INFN, Sezione di Milano Bicocca, Milan (Italy); Dafinei, I.; Orio, F.; Tomei, C.; Vignati, M. [INFN, Sezione di Roma, Rome (Italy); Di Domizio, S. [INFN, Sezione di Genova, Genoa (Italy); Universita di Genova, Dipartimento di Fisica, Genoa (Italy); Giuliani, A. [Centre de Spectrometrie de Masse, Orsay (France); Gotti, C.; Pessina, G.; Previtali, E.; Rusconi, C. [INFN, Sezione di Milano Bicocca, Milan (Italy); Laubenstein, M.; Nisi, S.; Pattavina, L.; Pirro, S.; Schaeffner, K. [INFN, Laboratori Nazionali del Gran Sasso, Assergi (L' Aquila) (Italy); Nagorny, S.; Pagnanini, L. [Gran Sasso Science Institute, L' Aquila (Italy); Nones, C. [SPP Centre de Saclay, CEA, Irfu, Gif-sur-Yvette (France)

    2015-12-15

    The LUCIFER project aims at deploying the first array of enriched scintillating bolometers for the investigation of neutrinoless double-beta decay of {sup 82}Se. The matrix which embeds the source is an array of ZnSe crystals, where enriched {sup 82}Se is used as decay isotope. The radiopurity of the initial components employed for manufacturing crystals, that can be operated as bolometers, is crucial for achieving a null background level in the region of interest for double-beta decay investigations. In this work, we evaluated the radioactive content in 2.5 kg of 96.3 % enriched {sup 82}Se metal, measured with a high-purity germanium detector at the Gran Sasso deep underground laboratory. The limits on internal contaminations of primordial decay chain elements of {sup 232}Th, {sup 238}U and {sup 235}U are respectively: <61, <110 and <74 μBq/kg at 90 % C.L. The extremely low-background conditions in which the measurement was carried out and the high radiopurity of the {sup 82}Se allowed us to establish the most stringent lower limits on the half-lives of the double-beta decay of {sup 82}Se to 0{sub 1}{sup +}, 2{sub 2}{sup +} and 2{sub 1}{sup +} excited states of {sup 82}Kr of 3.4.10{sup 22}, 1.3.10{sup 22} and 1.0.10{sup 22} y, respectively, with a 90 % C.L. (orig.)

  17. Double-beta decay investigation with highly pure enriched {sup 82}Se for the LUCIFER experiment

    Energy Technology Data Exchange (ETDEWEB)

    Beeman, J. W. [Lawrence Berkeley National Laboratory, 94720, Berkeley, CA (United States); Bellini, F. [Dipartimento di Fisica, Sapienza Università di Roma, 00185, Rome (Italy); INFN, Sezione di Roma, 00185, Rome (Italy); Benetti, P. [Dipartimento di Chimica, Università di Pavia, 27100, Pavia (Italy); INFN, Sezione di Pavia, 27100, Pavia (Italy); Cardani, L. [Dipartimento di Fisica, Sapienza Università di Roma, 00185, Rome (Italy); Physics Department, Princeton University, 08544, Princeton, NJ (United States); Casali, N. [Dipartimento di Fisica, Sapienza Università di Roma, 00185, Rome (Italy); INFN, Sezione di Roma, 00185, Rome (Italy)

    2015-12-13

    The LUCIFER project aims at deploying the first array of enriched scintillating bolometers for the investigation of neutrinoless double-beta decay of {sup 82}Se. The matrix which embeds the source is an array of ZnSe crystals, where enriched {sup 82}Se is used as decay isotope. The radiopurity of the initial components employed for manufacturing crystals, that can be operated as bolometers, is crucial for achieving a null background level in the region of interest for double-beta decay investigations. In this work, we evaluated the radioactive content in 2.5 kg of 96.3 % enriched {sup 82}Se metal, measured with a high-purity germanium detector at the Gran Sasso deep underground laboratory. The limits on internal contaminations of primordial decay chain elements of {sup 232}Th, {sup 238}U and {sup 235}U are respectively: <61, <110 and <74 μBq/kg at 90 % C.L. The extremely low-background conditions in which the measurement was carried out and the high radiopurity of the {sup 82}Se allowed us to establish the most stringent lower limits on the half-lives of the double-beta decay of {sup 82}Se to 0{sub 1}{sup +}, 2{sub 2}{sup +} and 2{sub 1}{sup +} excited states of {sup 82}Kr of 3.4·10{sup 22}, 1.3·10{sup 22} and 1.0·10{sup 22} y, respectively, with a 90 % C.L.

  18. Irradiation of pyrimidine in pure H2O ice with high-energy ultraviolet photons.

    Science.gov (United States)

    Nuevo, Michel; Chen, Yu-Jung; Hu, Wei-Jie; Qiu, Jun-Ming; Wu, Shang-Ruei; Fung, Hok-Sum; Chu, Ching-Chi; Yih, Tai-Sone; Ip, Wing-Huen; Wu, C-Y Robert

    2014-02-01

    The detection of nucleobases, the informational subunits of DNA and RNA, in several meteorites suggests that these compounds of biological interest were formed via astrophysical, abiotic processes. This hypothesis is in agreement with recent laboratory studies of irradiation of pyrimidine in H2O-rich ices with vacuum UV photons emitted by an H2-discharge lamp in the 6.9-11.3 eV (110-180 nm) range at low temperature, shown to lead to the abiotic formation of several compounds including the nucleobases uracil, cytosine, and thymine. In this work, we irradiated H2O:pyrimidine ice mixtures under astrophysically relevant conditions (14 K, ≤10(-9) torr) with high-energy UV photons provided by a synchrotron source in three different ranges: the 0(th) order light (4.1-49.6 eV, 25-300 nm), the He i line (21.2 eV, 58.4 nm), and the He ii line (40.8 eV, 30.4 nm). The photodestruction of pyrimidine was monitored with IR spectroscopy, and the samples recovered at room temperature were analyzed with liquid and gas chromatographies. Uracil and its precursor 4(3H)-pyrimidone were found in all samples, with absolute and relative abundances varying significantly from one sample to another. These results support a scenario in which compounds of biological interest can be formed and survive in environments subjected to high-energy UV radiation fields.

  19. Surface-Bound Intermediates in Low-Temperature Methanol Synthesis on Copper. Participants and Spectators

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yong; Mei, Donghai; Peden, Charles HF; Campbell, Charles T.; Mims, Charles A.

    2015-11-03

    The reactivity of surface adsorbed species present on copper catalysts during methanol synthesis at low temperatures was studied by simultaneous infrared spectroscopy (IR) and mass spectroscopy (MS) measurements during “titration” (transient surface reaction) experiments with isotopic tracing. The results show that adsorbed formate is a major bystander species present on the surface under steady-state methanol synthesis reaction conditions, but it cannot be converted to methanol by reaction with pure H2, nor with H2 plus added water. Formate-containing surface adlayers for these experiments were produced during steady state catalysis in (a) H2:CO2 (with substantial formate coverage) and (b) moist H2:CO (with no IR visible formate species). Both these reaction conditions produce methanol at steady state with relatively high rates. Adlayers containing formate were also produced by (c) formic acid adsorption. Various "titration" gases were used to probe these adlayers at modest temperatures (T = 410-450K) and 6 bar total pressure. Methanol gas (up to ~1% monolayer equivalent) was produced in "titration" from the H2:CO2 catalytic adlayers by H2 plus water, but not by dry hydrogen. The decay in the formate IR features accelerated in the presence of added water vapor. The H2:CO:H2O catalytic adlayer produced similar methanol titration yields in H2 plus water but showed no surface formate features in IR (less than 0.2% monolayer coverage). Finally, formate from formic acid chemisorption produced no methanol under any titration conditions. Even under (H2:CO2) catalytic reaction conditions, isotope tracing showed that pre-adsorbed formate from formic acid did not contribute to the methanol produced. Although non-formate intermediates exist during low temperature methanol synthesis on copper which can be converted to methanol gas

  20. Insights on the effective incorporation of a foam-based methanol reformer in a high temperature polymer electrolyte membrane fuel cell

    Science.gov (United States)

    Avgouropoulos, George; Papavasiliou, Joan; Ioannides, Theophilos; Neophytides, Stylianos

    2015-11-01

    Highly active Al-doped CuMnOx catalyst supported on metallic copper foam was prepared via the combustion method and placed adjacent to the anode electrocatalyst of a high temperature PEM fuel cell operating at 200-210 °C. The addition of aluminum oxide in the catalyst composition enhanced the specific surface area (19.1 vs. 8.6 m2 g-1) and the reducibility of the Cu-Mn spinel oxide. Accordingly, the catalytic performance of CuMnOx was also improved. The doped sample is up to 2.5 times more active than the undoped sample at 200 °C, depending on the methanol concentration at the inlet, while CO selectivity is less than 0.8% in all cases. A membrane-electrode assembly comprising the ADVENT cross-linked TPS® high-temperature polymer electrolyte was integrated with the Cu-based methanol reformer in an Internal Reforming Methanol Fuel Cell (IRMFC). In order to avoid extensive poisoning of the reforming catalyst by H3PO4, a thin separation plate was placed between the reforming catalyst and the electrooxidation catalyst. Preliminary results obtained from a single-cell laboratory prototype demonstrated the improved functionality of the unit. Indeed, promising electrochemical performance was obtained during the first 24 h, during which the required H2 for achieving 580 mV at 0.2 A cm-2, was supplied from the reformer.

  1. Isolation of alkaliphilic bacteria for production of high optically pure L-(+)-lactic acid.

    Science.gov (United States)

    Yokaryo, Hiroto; Tokiwa, Yutaka

    2014-01-01

    Lactic acid bacteria that grow under alkaline conditions (pH 10) were isolated from various sources in Okinawa (Japan). These alkali-tolerant and alkaliphilic bacteria were classified as follows: Microbacterium sp. (1 strain), Enterococcus spp. (9 strains), Alkalibacterium spp. (3 strains), Exiguobacterium spp. (5 strains), Oceanobacillus spp. (3 strains) and Bacillus spp. (7 strains) by 16S rRNA gene sequencing. By fermentation, many strains were able to convert glucose into mainly L-(+)-lactic acid of high optical purity in alkaline broth. This result indicated that valuable L-(+)-lactic acid-producing bacteria could be isolated efficiently by screening under alkaline conditions. Six strains were selected and their ability to produce lactic acid at different initial pH was compared. Enterococcus casseliflavus strain 79w3 gave the highest lactic acid concentration. Lactic acid concentration and productivity were 103 g L(-1) (optical purity of 99.5% as L-isomer) and 2.2 g L(-1) h(-1), respectively when 129 g L(-1) of glucose was used by batch fermentation.

  2. Surface nanostructures in commercial pure Ti induced by high energy shot peening

    Institute of Scientific and Technical Information of China (English)

    CHEN Chun-huan; REN Rui-ming; ZHAO Xiu-juan; ZHANG Yu-jun

    2004-01-01

    The high-energy shot peening (HESP) technique was used to obtain the surface nanocrystalline microstructure for a hcp metal titanium. XRD, SEM and TEM were applied to characterize the microstructure of the surface layer. Large amount of the deformation twins in the surface layer were observed by SEM in the specimens after HESP treatment in a shot-time, and the number of deformation twins both in a single plane and in intersecting planes increases with HESP time, until the twin character disappears completely in the top surface layer, which means that the severe plastic deformation(SPD) occurs on the surface. The XRD analysis results show that after HESP treatmen for 30 - 60 min the surface grain size decreases to nanoscale. According to the TEM images and corresponding diffraction patterns from SPD areas of the 120 min-treatment specimen, the measured grain size near the surface is about 20 - 30 nm. The grain size in deformation layer increases with the depth from the surface, and the nanostructured layer is about 20 μm in depth. Therefore, the surface nanocrystalline and a gradient microstructure from the surface to the matrix are obtained, which results in the micro-hardness decreasing from surface to the matrix gradually.

  3. Pure neuritic leprosy in patients from a high endemic region of Colombia.

    Science.gov (United States)

    Rodriguez, Gerzain; Pinto, Rafael; Gomez, Yenny; Rengifo, Maria Leonor; Estrada, Olga Lucia; Sarmiento, Marta; Lopez, Fernando; Beltran-Alzate, Juan Camilo; Cardona-Castro, Nora

    2013-03-01

    Agua de Dios was a leprosarium for leprosy patients' obligatory isolation (1872-1961). Its leprosy incidence is the highest in Colombia (1.5-7/10000). Relapses are common. Government grant of US$ 200 per month subsidy is available to patients with disabilities. Spontaneous consultation with neural symptoms is frequent and simulation to get the subsidy has to be considered. We studied 36 subjects (2007-2009), with ages from 29-78, 19 of them men, with neural symptoms of 6 months to 20 years evolution. All had clinical examination, bacteriological examination, skin and nerve biopsies, electromyography (EMG), PCR for M. leprae, IgM anti-PGL1, and lepromin A. All but two are household contacts of leprosy patients. Symptoms were hypoesthesia of the hands and feet, and difficulty using hands with loss of muscular strength. None had skin lesions. Three had thickening of ulnar nerve. Lepromin was positive in all; bacteriology and biopsies were negative in all. The speed and amplitude of neural conduction were altered in 34 patients; two women had normal EMG and were considered to be feigning the disease; 21 were diagnosed as PNL by clinical, epidemiological and EMG findings; five of them had a positive PCR and one, high titers for IgM anti PGL1. Nine other subjects had diabetes and six carpal tunnel syndrome (CTS). Slow progression of disease, the lack of neural enlargement and the neural biopsies without inflammation suggest that most of these patients could have spontaneously cured PNL, as happens with other cases of paucibacillary leprosy. Diabetes and CTS are important differential diagnoses of PNL. Patients were treated with MDT and received the state subsidy.

  4. Accidental methanol ingestion: Case report

    Directory of Open Access Journals (Sweden)

    Bakker Jan

    2010-02-01

    Full Text Available Abstract Background The incidence of methanol (CH3OH intoxication differs enormously from country to country. Methanol intoxication is extremely rare in the Dutch population. Even a low dose can already be potentially lethal. Patients are conventionally treated with hemodialysis. Therefore we'd like to present a report of a foreign sailor in Rotterdam who accidentally caused himself severe methanol intoxication, with a maximum measured concentration of 4.4 g/L. Case presentation The patient presented with hemodynamic instability and severe metabolic acidosis with pH 6.69. The anion gap was 39 mmol/L and the osmol gap 73 mosmol/kg. Treatment with ethanol and continuous venovenous hemodiafiltration (CVVH-DF was initiated. Despite the hemodynamic instability it is was possible to achieve rapid correction of pH and methanol concentration with CVVH-DF while maintaining a stable and therapeutic ethanol serum concentration. Despite hemodynamic and acid-base improvement, our patient developed massive cerebral edema leading to brain death. Permission for organ donation was unfortunately not ascertained. Conclusions We conclude that in a hemodynamic instable situation high methanol concentrations and methanol-induced derangements of homeostasis are safely and effectively treated with CVVH-DF and that severe cerebral edema is another possible cause of death rather than the classical bleeding in the putamen area.

  5. Comparative analysis of deuterium ions implanted and deuterium atoms saturated at high pressure in pure pd and Pd diluted alloys

    Science.gov (United States)

    Didyk, A. Yu.; Kulikauskas, V. S.; Wiśniewski, R.; Wilczynska, T.; Kitowski, K.

    2012-01-01

    Pd and its diluted alloys (Pd-Ag, Pd-Pt, Pd-Ru, Pd-Rh) were implanted by 25 keV deuterium ions at a fluence interval of (1.2-2.3) × 1022 m-2. The same property alloys were saturated by deuterium atoms using high pressure chamber during long period with temperature stabilization and electrical resistance measurement of standard Pd wire. The post-treatment depth distributions of deuterium and accompanied hydrogen atoms were measured immediately after implantation (ten days) and after definite time period (three months) after saturation with the usage of elastic recoil detection analysis (ERDA). After two months, the measurements were repeated. The comparison of obtained results in both series of studies allowed one to make an important observation of a relative stability of deuterium and hydrogen atoms in pure Pd and its diluted alloys.

  6. Synthesis, Tunable Multicolor Output, and High Pure Red Upconversion Emission of Lanthanide-Doped Lu2O3 Nanosheets

    Directory of Open Access Journals (Sweden)

    Lingzhen Yin

    2013-01-01

    Full Text Available Yb3+ and Ln3+ (Ln = Er, Ho codoped Lu2O3 square nanocubic sheets were successfully synthesized via a facile hydrothermal method followed by a subsequent dehydration process. The crystal phase, morphology, and composition of hydroxide precursors and target oxides were characterized by X-ray diffraction (XRD, field emission scanning electron microscope (FE-SEM, and energy-dispersive X-ray spectroscope (EDS. Results present the as-prepared Lu2O3 crystallized in cubic phase, and the monodispersed square nanosheets were maintained both in hydroxide and oxides. Moreover, under 980 nm laser diode (LD excitation, multicolor output from red to yellow was realized by codoped different lanthanide ions in Lu2O3. It is noteworthy that high pure strong red upconversion emission with red to green ratio of 443.3 of Er-containing nanocrystals was obtained, which is beneficial for in vivo optical bioimaging.

  7. Online stable carbon isotope ratio measurement in formic acid, acetic acid, methanol and ethanol in water by high performance liquid chromatography-isotope ratio mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tagami, Keiko [National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555 (Japan)], E-mail: k_tagami@nirs.go.jp; Uchida, Shigeo [National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555 (Japan)

    2008-05-05

    A suitable analysis condition was determined for high performance liquid chromatography-isotope ratio mass spectrometry (HPLC-IRMS) while making sequential measurements of stable carbon isotope ratios of {delta}{sup 13}C in formic acid, acetic acid, methanol and ethanol dissolved in water. For this online column separation method, organic reagents are not applicable due to carbon contamination; thus, water and KH{sub 2}PO{sub 4} at low concentrations were tested as mobile phase in combination with a HyPURITY AQUASTAR{sup TM} column. Formic acid, acetic acid, methanol and ethanol were separated when 2 mM KH{sub 2}PO{sub 4} aqueous solution was used. Under the determined analysis condition for HPLC-IRMS, carbon concentrations could be measured quantitatively as well as carbon isotope ratio when carbon concentration was higher than 0.4 mM L for each chemical.

  8. Direct and Highly Selective Conversion of Synthesis Gas into Lower Olefins: Design of a Bifunctional Catalyst Combining Methanol Synthesis and Carbon-Carbon Coupling.

    Science.gov (United States)

    Cheng, Kang; Gu, Bang; Liu, Xiaoliang; Kang, Jincan; Zhang, Qinghong; Wang, Ye

    2016-04-01

    The direct synthesis of lower (C2 to C4) olefins, key building-block chemicals, from syngas (H2/CO), which can be derived from various nonpetroleum carbon resources, is highly attractive, but the selectivity for lower olefins is low because of the limitation of the Anderson-Schulz-Flory distribution. We report that the coupling of methanol-synthesis and methanol-to-olefins reactions with a bifunctional catalyst can realize the direct conversion of syngas to lower olefins with exceptionally high selectivity. We demonstrate that the choice of two active components and the integration manner of the components are crucial to lower olefin selectivity. The combination of a Zr-Zn binary oxide, which alone shows higher selectivity for methanol and dimethyl ether even at 673 K, and SAPO-34 with decreased acidity offers around 70% selectivity for C2-C4 olefins at about 10% CO conversion. The micro- to nanoscale proximity of the components favors the lower olefin selectivity.

  9. Soft magnetic properties and high frequency characteristics of FeM (M = B, Hf, Zr) and pure Fe films fabricated by oblique deposition

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chengcheng; Zhang, Chao; Wang, Fenglong; Zhao, Zhong; Jiang, Changjun; Xue, Desheng [Lanzhou University, Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou (China); Lanzhou University, Key Laboratory of Special Function Materials and Structure Design of Ministry of Education, Lanzhou (China)

    2015-09-15

    To improve the high-frequency properties of Fe-based thin films, doped and pure Fe thin films were obliquely deposited on Si (100) substrate by RF-magnetron sputtering. Vibrating sample magnetometer (VSM) measurements show obvious in-plane uniaxial magnetic anisotropy in both doped and pure Fe thin films, and enhancement effects of doping on Soft magnetic properties were also observed. Microwave permeability measurements indicate that the resonance frequency and permeability of pure Fe films are much larger than those of doped Fe thin films. Damping factors of Fe thin films deposited at different oblique angles were further investigated. (orig.)

  10. Porous Pt Nanotubes with High Methanol Oxidation Electrocatalytic Activity Based on Original Bamboo-Shaped Te Nanotubes.

    Science.gov (United States)

    Lou, Yue; Li, Chunguang; Gao, Xuedong; Bai, Tianyu; Chen, Cailing; Huang, He; Liang, Chen; Shi, Zhan; Feng, Shouhua

    2016-06-29

    In this report, a facile and general strategy was developed to synthesize original bamboo-shaped Te nanotubes (NTs) with well-controlled size and morphology. On the basis of the as-prepared Te NTs, porous Pt nanotubes (NTs) with excellent property and structural stability have been designed and manufactured. Importantly, we avoided the use of surface stabilizing agents, which may affect the catalytic properties during the templated synthesis process. Furthermore, Pt NTs with different morphology were successfully prepared by tuning the experimental parameters. As a result, transmission electron microscopy (TEM) study shows that both Te NTs and Pt NTs have uniform size and morphology. Following cyclic voltammogram (CV) testing, the as-prepared porous Pt NTs and macroporous Pt NTs exhibited excellent catalytic activities toward electrochemical methanol oxidation reactions due to their tubiform structure with nanoporous framework. Thus, the as-prepared Pt NTs with specific porous structure hold potential usage as alternative anode catalysts for direct methanol fuel cells (DMFCs).

  11. The influence of surface roughness and high pressure torsion on the growth of anodic titania nanotubes on pure titanium

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Nan; Gao, Nong, E-mail: N.Gao@soton.ac.uk; Starink, Marco J.

    2016-11-30

    Highlights: • HPT has substantially improved the UTS and Hv of pure Ti. • TNT layers was fabricated on UFG Ti made by HPT. • Influence of sample preparation on TNT layers was systematically studied. • Oxide dissolution was accelerated when TNTs formed on the HPT sample. - Abstract: Anodic titanium dioxide nanotube (TNT) arrays have wide applications in photocatalytic, catalysis, electronics, solar cells and biomedical implants. When TNT coatings are combined with severe plastic deformation (SPD), metal processing techniques which efficiently improve the strength of metals, a new generation of biomedical implant is made possible with both improved bulk and surface properties. This work investigated the effect of processing by high pressure torsion (HPT) and different mechanical preparations on the substrate and subsequently on the morphology of TNT layers. HPT processing was applied to refine the grain size of commercially pure titanium samples and substantially improved their strength and hardness. Subsequent anodization at 30 V in 0.25 wt.% NH{sub 4}F for 2 h to form TNT layers on sample surfaces prepared with different mechanical preparation methods was carried out. It appeared that the local roughness of the titanium surface on a microscopic level affected the TNT morphology more than the macroscopic surface roughness. For HPT-processed sample, the substrate has to be pre-treated by a mechanical preparation finer than 4000 grit for HPT to have a significant influence on TNTs. During the formation of TNT layers the oxide dissolution rate was increased for the ultrafine-grained microstructure formed due to HPT processing.

  12. Development of new heterogeneous catalysts for the decomposition of methanol into hydrogen and carbon monoxide applying high throughput methods; Entwicklung neuer heterogener Katalysatoren zur Spaltung von Methanol in Wasserstoff und Kohlenmonoxid mittels Hochdurchsatz-Methoden

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, Torsten

    2008-07-11

    The topic of this thesis has been the development of new heterogeneous catalysts for the decomposition of methanol into hydrogen and carbon monoxide. As an important constraint here, the content of noble metals of the catalysts should be as low as possible. High-throughput-methods were applied in some of the syntheses and experiments to accelerate the development, as, for example, the use of liquid based sol-gel syntheses and the examination of catalyst libraries by spatial resolution gas chromatography. This screening technique allowed to test up to 207 different substances during one single experiment. Then, different combinatorial strategies were applied. First, these methods led to a highly active and stable catalyst in the ternary system of Cu-Ni-Zn, which showed high conversion and selectivity comparable to an industrial reference catalyst. Its activity during an 18 hour long term run was constant in contrast to the reference. Second, an additional approach starting from a broader variety of elements led to a Ce- Ru- and to a Cr-Ru-catalyst. Both of them were highly active in short term experiments, but lost their outstanding performances during long term runs. (orig.) [German] Die vorliegende Arbeit befasste sich mit der Entwicklung neuer heterogener Katalysatoren fuer die Spaltung von Methanol zu Wasserstoff und Kohlenmonoxid, die einen moeglichst geringen Gehalt an Edelmetallen aufweisen sollten. Um diesen Prozess zu beschleunigen, wurden in einem Teil der Synthesen und Experimente Hochdurchsatzmethoden verwendet. Neben der Roboter gestuetzten Sol-Gel-Synthese umfasste dies die Untersuchung von Katalysatorbibliotheken mittels ortsaufgeloester Gaschromatographie, die es ermoeglichte, in einem Experiment bis zu 207 verschiedene Substanzen auf ihre katalytische Aktivitaet zu testen. Unter Anwendung verschiedener kombinatorischer Strategien wurde zunaechst ein sehr aktiver und stabiler Katalysator im ternaeren Cu-Ni-Zn-System entdeckt. Neben Umsaetzen und

  13. Parallaxes of 6.7-GHz Methanol Masers towards the G305.2 High-Mass Star Formation Region

    CERN Document Server

    Krishnan, V; Reid, M J; Bignall, H E; McCallum, J; Phillips, C J; Reynolds, C; Stevens, J

    2016-01-01

    We have made measurements to determine the parallax and proper motion of the three 6.7-GHz methanol masers G305.200$+$0.019, G305.202$+$0.208 and G305.208$+$0.206. The combined parallax is found to be 0.25$\\pm $0.05 mas, corresponding to a distance of 4.1$^{+1.2}_{-0.7}$ kpc. This places the G305.2 star formation region in the Carina-Sagittarius spiral arm. The inclusion of G305.2 increases the Galactic azimuth range of the sources in this arm by 40$^\\circ $ from Sato et al., allowing us to determine the pitch angle of this spiral with greater confidence to be $\\psi = 19.0 \\pm 2.6^\\circ $. The first VLBI spot maps of the 6.7-GHz methanol masers towards these sources show that they have simple linear and ring-like structures, consistent with emission expected from classII methanol masers in general.

  14. Parallaxes of 6.7-GHz methanol masers towards the G 305.2 high-mass star formation region

    Science.gov (United States)

    Krishnan, V.; Ellingsen, S. P.; Reid, M. J.; Bignall, H. E.; McCallum, J.; Phillips, C. J.; Reynolds, C.; Stevens, J.

    2017-02-01

    We have made measurements to determine the parallax and proper motion of the three 6.7-GHz methanol masers G 305.200+0.019, G 305.202+0.208 and G 305.208+0.206. The combined parallax is found to be 0.25±0.05 mas, corresponding to a distance of 4.1^{+1.2}_{-0.7} kpc. This places the G 305.2 star formation region in the Carina-Sagittarius spiral arm. The inclusion of G 305.2 increases the Galactic azimuth range of the sources in this arm by 40° from Sato et al., allowing us to determine the pitch angle of this spiral with greater confidence to be ψ = 19.0° ± 2.6°. The first very long baseline interferometry spot maps of the 6.7-GHz methanol masers towards these sources show that they have simple linear and ring-like structures, consistent with emission expected from class II methanol masers in general.

  15. Highly selective hydrogenation of CO2 to methanol over CuO-ZnO-ZrO2 catalysts prepared by a surfactant-assisted co-precipitation method

    Science.gov (United States)

    Li, Li; Mao, Dongsen; Yu, Jun; Guo, Xiaoming

    2015-04-01

    A series of CuO-ZnO-ZrO2 catalysts are synthesized by a surfactant-assisted co-precipitation method and tested for the synthesis of methanol from CO2 hydrogenation. The effects of calcination temperature on the physicochemical properties of as-prepared catalysts are investigated extensively by TG-DSC, N2 adsorption/desorption, XRD, N2O chemisorption, SEM/TEM, EDX, XPS, TPR, H2-TPD and CO2-TPD techniques. The results show that the size of copper particles increases with the increase in calcination temperature, leading to the decrease in turnover frequency (TOF) for methanol formation. Moreover, compared with the counterparts prepared by the conventional co-precipitation method, the CuO-ZnO-ZrO2 catalysts prepared by this novel method show significantly high methanol selectivity. The superior property of the prepared CuO-ZnO-ZrO2 catalyst can be attributed to the formation of more amounts of Cu-ZnOx and/or Cu-ZrOx species resulted from the homogeneous element distribution, intimate interface contact of Cu species with ZnO and/or ZrO2, and to porous structure with larger pore size.

  16. Dynamic Hydrogen Production from Methanol/Water Photo-Splitting Using Core@Shell-Structured CuS@TiO2 Catalyst Wrapped by High Concentrated TiO2 Particles

    Directory of Open Access Journals (Sweden)

    Younghwan Im

    2013-01-01

    Full Text Available This study focused on the dynamic hydrogen production ability of a core@shell-structured CuS@TiO2 photocatalyst coated with a high concentration of TiO2 particles. The rectangular-shaped CuS particles, 100 nm in length and 60 nm in width, were surrounded by a high concentration of anatase TiO2 particles (>4~5 mol. The synthesized core@shell-structured CuS@TiO2 particles absorbed a long wavelength (a short band gap above 700 nm compared to that pure TiO2, which at approximately 300 nm, leading to easier electronic transitions, even at low energy. Hydrogen evolution from methanol/water photo-splitting over the core@shell-structured CuS@TiO2 photocatalyst increased approximately 10-fold compared to that over pure CuS. In particular, 1.9 mmol of hydrogen gas was produced after 10 hours when 0.5 g of 1CuS@4TiO2 was used at pH = 7. This level of production was increased to more than 4-fold at higher pH. Cyclic voltammetry and UV-visible absorption spectroscopy confirmed that the CuS in CuS@TiO2 strongly withdraws the excited electrons from the valence band in TiO2 because of the higher reduction potential than TiO2, resulting in a slower recombination rate between the electrons and holes and higher photoactivity.

  17. Developmental and Reproductive Toxicology of Methanol

    Science.gov (United States)

    Methanol is a high production volume chemical used as a feedstock for chemical syntheses and as a solvent and fuel additive. Methanol is acutely toxic to humans, causing acidosis, blindness in death at high dosages, but its developmental and reproductive toxicity in humans is poo...

  18. Structural and Optical Properties of Ultra-high Pure Hot Water Processed Ga2O3 Thin Film

    Directory of Open Access Journals (Sweden)

    Subramani SHANMUGAN

    2016-05-01

    Full Text Available Thin film based gas sensor is an advanced application of thin film especially Ga2O3 (GO thin film gas sensor is useful for high temperature gas sensor. The effect of moisture or environment on thin film properties has more influence on gas sensing properties. Radio Frequency sputtered Ga2O3 thin film was synthesized and processed in ultra-high pure hot water at 95 °C for different time durations. The structural properties were verified by the Xray Diffraction technique and the observed spectra revealed the formation of hydroxyl compound of Gallium (Gallium Oxide Dueterate – GOD on the surface of the thin film and evidenced for structural defects as an effect of moisture. Decreased crystallite size and increased dislocation density was showed the crystal defects of prepared film. From the Ultra Violet – Visible spectra, decreased optical transmittance was noticed for various processing time. The formation of needle like GOD was confirmed using Field Emission Secondary Electron Microscope (FESEM images.DOI: http://dx.doi.org/10.5755/j01.ms.22.2.7186

  19. Unusual case of methanol poisoning

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, L.; Henderson, M. (St. James' s Univ. Hospital, Leeds (United Kingdom). Dept. of Chemical Pathology); Madi, S.; Mellor, L. (St. James' s Univ. Hospital, Leeds (United Kingdom). Dept. of Medicine, and Pharmacy)

    1993-01-09

    A 31-year-old man with a history of alcohol abuse presented to the accident and emergency department complaining of blurred vision. 4 h previously he had drunk 300 mL de-icer fluid. Electrolytes, urea, creatinine, glucose, and blood-gas analysis were normal. Measured osmolality, however, was 368 mosmol/kg with a calculated osmolality of 300 mosmol/kg, which indicated a greatly increased osmolar gap. He was therefore given 150 mL whisky and admitted. Methanol was later reported as 200 mg/dL. Ethylene glycol was not detected, but another glycol, propylene glycol, was present at 47 mg/dL. 10 h after ingestion an intravenous infusion of ethanol was started and he was hemodialysed for 7 h. After dialysis he was given a further 100 mL whisky and the rate of ethanol infusion was reduced to 11 g per h. Methanol and ethanol were measured twice daily until methanol was under 10/mg/dL: The recommendation is that blood ethanol be maintained between 100 and 200 mg/dL during treatment of methanol poisoning. This concentration was not achieved, presumably because of the high rate of ethanol metabolism often found in alcoholics. Antifreeze solutions commonly contain methanol and ethylene glycol. Sometimes propylene glycol is substituted because it has properties similar to those of ethylene glycol but is less toxic. The authors postulate that propylene glycol inhibited the metabolism of methanol in the patient, thus sparing him from the toxic effects of methanol.

  20. Conductivity and methanol permeability of Nafion-zirconium phosphate composite membranes containing high aspect ratio filler particles

    Energy Technology Data Exchange (ETDEWEB)

    Bagnasco, G.; Micoli, L.; Turco, M. [Dipartimento di Ingegneria Chimica, Universita di Napoli Federico II, P.le V. Tecchio 80, 80125 - Napoli (Italy); Donnadio, A.; Pica, M.; Sganappa, M. [Dipartimento di Chimica, Universita di Perugia, via Elce di Sotto 8, 06123 - Perugia (Italy); Casciola, M.

    2009-08-15

    Gels of exfoliated {alpha}-zirconium phosphate (ZrP{sub exf}) in dimethylformamide (DMF) were used to prepare Nafion/ZrP{sub exf} composite membranes with filler loadings up to 7 wt.-% by casting mixtures of Nafion 1100 solutions in DMF and suitable amounts of 2 wt.-% ZrP gels in DMF. TEM pictures showed that the ZrP{sub exf} particles had aspect ratio of at least 20. All samples were characterised by methanol permeability (P) and through-plane ({sigma}{sub thp}) and in-plane ({sigma}{sub inp}) conductivity measurements at 40 C and 100% RH. The methanol permeability of Nafion membranes containing in situ grown ZrP particles with low aspect ratio (Nafion/ZrP{sub isg}) was also determined. The methanol permeability and the swelling behaviour of the composite membranes turned out to be strongly dependent on the filler morphology. As a general trend, both permeability and swelling decreased according to the sequence: Nafion/ZrP{sub isg} > Nafion > Nafion/ZrP{sub exf}. The maximum selectivity ({sigma}{sub thp}/P = 1.4 x 10{sup 5} S cm{sup -3} s) was found for the membrane filled with 1 wt.-% ZrP{sub exf}: this value is seven times higher than that of Nafion. For the Nafion/ZrP{sub exf} membranes, the ratio {sigma}{sub inp}/{sigma}{sub thp} increases with the filler loading, thus indicating that the preferred orientation of the ZrP sheets is parallel to the membrane surface. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  1. System model development for a methanol reformed 5 kW high temperature PEM fuel cell system

    DEFF Research Database (Denmark)

    Sahlin, Simon Lennart; Andreasen, Søren Juhl; Kær, Søren Knudsen

    2015-01-01

    This work investigates the system performance when reforming methanol in an oil heated reformer system for a 5 kW fuel cell system. A dynamic model of the system is created and evaluated. The system is divided into 4 separate components. These components are the fuel cell, reformer, burner...... and evaporator, which are connected by two separate oil circuits, one with a burner and reformer and one with a fuel cell and evaporator. Experiments were made on the reformer and measured oil and bed temperatures are presented in multiple working points. The system is examined at loads from 0 to 5000 W electric...

  2. Design of efficient methanol impermeable membranes for fuel cell applications.

    Science.gov (United States)

    Lufrano, F; Baglio, V; Di Blasi, O; Staiti, P; Antonucci, V; Aricò, A S

    2012-02-28

    In this paper, the design of efficient composite membranes based on sulfonated polysulfone and acidic silica material with characteristics and properties such as methanol barrier, high proton conductivity and suitable fuel cells performance is presented. A positive influence of nanosized acidic silica powders, used as an additive filler in the preparation of composite membranes, due to an efficient hydrophilic inter-distribution inside the membrane when compared to pure silica, is found. A series of different techniques such as XRF, FT-IR, TGA, DSC, IEC and conductivity measurements are used to highlight the properties of acidic silica material and composite membranes. The composite membrane based on acidic silica (SPSf-SiO(2)-S) shows the lowest crossover current (only 8 mA cm(-2)), which is 43% lower than that of a pure SPSf membrane and 33% lower compared to a composite membrane based on bare silica (SPSf-SiO(2)). These significant differences are attributed to the increasing diffusion path length of MeOH/H(2)O clusters in the composite membranes. The maximum DMFC performance at 30 °C is achieved with the SPSf-SiO(2)-S membrane (23 mW cm(-2)), whereas the MEAs based on SPSf-SiO(2) and pure SPSf membranes reached 21 and 16 mW cm(-2), respectively. These significant results of the composite SPSf-SiO(2)-S membrane are ascribed at a good compromise among high proton conductivity, low swelling and low methanol crossover compared to pure SPSf and (unmodified silica)-SPSf membranes. A preliminary short durability test of 100 h performed in a cell with the composite SPSf-SiO(2)-S membrane shows remarkable performance stability during chrono-voltammetric measurements (60 mA cm(-2)) at 30 °C.

  3. Reforming of methanol and glycerol in supercritical water

    NARCIS (Netherlands)

    van Bennekom, J. G.; Venderbosch, R. H.; Assink, D.; Heeres, H. J.

    2011-01-01

    Reforming of pure glycerol, crude glycerin, and methanol (pure and in the presence of Na(2)CO(3)) in supercritical water was investigated. Continuous experiments were carried out at temperatures between 450 and 650 degrees C, residence times between 6 and 173 s, and feed concentrations of 3-20 wt%.

  4. Measurement and Analysis of Spall Characteristics of High-Pure Aluminium at One-Dimensional Strain Loading

    Institute of Scientific and Technical Information of China (English)

    QI Mei-Lan; HE Hong-Liang; YAN Shi-Lin

    2007-01-01

    @@ With an impact velocity varying from 196.9m/s to 317.9m/s and ratios of flyer/sample thickness of 2:4 and 3:6, the free-surface velocity profiles of the shock compressed high purity aluminium (HPA 99.999%) samples are measured with a velocity interferometer system for any reflector. Based on the vibrating features of the velocity profiles, the damage behaviour of HPA is analysed. The results indicate that the vibrating amplitude incresdes with increasing shock stress, and the subsequent reverberations describing the spall become more obvious. When the shock stress in the material is below a critical or smaller than the threshold level, the free-surface velocity profile replicates virtually the form of the compression pulse inside the sample. When the impact stress exceeds a critical value (1.4 Gpa), the micro damage would appear, and the free-surface velocity profile changes significantly,showing a series of short-duration reverberations in the profile. When the impact stress exceeds the threshold of damage, a compressive disturbance called the "spall pulse" appears in the free-surface velocity profile, and the subsequent reverberation becomes regular again. The measured spall strength of HPA is much higher than those of commercially pure aluminium reported in many references. In addition, the strength of HPA is similar to that of single-crystal aluminium.

  5. Response Surface Optimization of Process Parameters and Fuzzy Analysis of Sensory Data of High Pressure-Temperature Treated Pineapple Puree.

    Science.gov (United States)

    Chakraborty, Snehasis; Rao, Pavuluri Srinivasa; Mishra, Hari Niwas

    2015-08-01

    The high-pressure processing conditions were optimized for pineapple puree within the domain of 400-600 MPa, 40-60 °C, and 10-20 min using the response surface methodology (RSM). The target was to maximize the inactivation of polyphenoloxidase (PPO) along with a minimal loss in beneficial bromelain (BRM) activity, ascorbic acid (AA) content, antioxidant capacity, and color in the sample. The optimum condition was 600 MPa, 50 °C, and 13 min, having the highest desirability of 0.604, which resulted in 44% PPO and 47% BRM activities. However, 93% antioxidant activity and 85% AA were retained in optimized sample with a total color change (∆E*) value less than 2.5. A 10-fold reduction in PPO activity was obtained at 600 MPa/70 °C/20 min; however, the thermal degradation of nutrients was severe at this condition. Fuzzy mathematical approach confirmed that sensory acceptance of the optimized sample was close to the fresh sample; whereas, the thermally pasteurized sample (treated at 0.1 MPa, 95 °C for 12 min) had the least sensory score as compared to others.

  6. The influence of surface roughness and high pressure torsion on the growth of anodic titania nanotubes on pure titanium

    Science.gov (United States)

    Hu, Nan; Gao, Nong; Starink, Marco J.

    2016-11-01

    Anodic titanium dioxide nanotube (TNT) arrays have wide applications in photocatalytic, catalysis, electronics, solar cells and biomedical implants. When TNT coatings are combined with severe plastic deformation (SPD), metal processing techniques which efficiently improve the strength of metals, a new generation of biomedical implant is made possible with both improved bulk and surface properties. This work investigated the effect of processing by high pressure torsion (HPT) and different mechanical preparations on the substrate and subsequently on the morphology of TNT layers. HPT processing was applied to refine the grain size of commercially pure titanium samples and substantially improved their strength and hardness. Subsequent anodization at 30 V in 0.25 wt.% NH4F for 2 h to form TNT layers on sample surfaces prepared with different mechanical preparation methods was carried out. It appeared that the local roughness of the titanium surface on a microscopic level affected the TNT morphology more than the macroscopic surface roughness. For HPT-processed sample, the substrate has to be pre-treated by a mechanical preparation finer than 4000 grit for HPT to have a significant influence on TNTs. During the formation of TNT layers the oxide dissolution rate was increased for the ultrafine-grained microstructure formed due to HPT processing.

  7. Pure-tone Audiometer

    Science.gov (United States)

    Kapul, A. A.; Zubova, E. I.; Torgaev, S. N.; Drobchik, V. V.

    2017-08-01

    The research focuses on a pure-tone audiometer designing. The relevance of the study is proved by high incidence of an auditory analyser in older people and children. At first, the article provides information about subjective and objective audiometry methods. Secondly, we offer block-diagram and basic-circuit arrangement of device. We decided to base on STM32F407VG microcontroller and use digital pot in the function of attenuator. Third, we implemented microcontroller and PC connection. C programming language is used for microcontroller’s program and PC’s interface. Fourthly, we created the pure-tone audiometer prototype. In the future, we will implement the objective method ASSR in addition to pure-tone audiometry.

  8. Development of a methanol reformer for fuel cell vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Lindstroem, Baard

    2003-03-01

    Vehicles powered by fuel cells are from an environmental aspect superior to the traditional automobile using internal combustion of gasoline. Power systems which are based upon fuel cell technology require hydrogen for operation. The ideal fuel cell vehicle would operate on pure hydrogen stored on-board. However, storing hydrogen on-board the vehicle is currently not feasible for technical reasons. The hydrogen can be generated on-board using a liquid hydrogen carrier such as methanol and gasoline. The objective of the work presented in this thesis was to develop a catalytic hydrogen generator for automotive applications using methanol as the hydrogen carrier. The first part of this work gives an introduction to the field of methanol reforming and the properties of a fuel cell based power system. Paper I reviews the catalytic materials and processes available for producing hydrogen from methanol. The second part of this thesis consists of an experimental investigation of the influence of the catalyst composition, materials and process parameters on the activity and selectivity for the production of hydrogen from methanol. In Papers II-IV the influence of the support, carrier and operational parameters is studied. In Paper V an investigation of the catalytic properties is performed in an attempt to correlate material properties with performance of different catalysts. In the third part of the thesis an investigation is performed to elucidate whether it is possible to utilize oxidation of liquid methanol as a heat source for an automotive reformer. In the study which is presented in Paper VI a large series of catalytic materials are tested and we were able to minimize the noble metal content making the system more cost efficient. In the final part of this thesis the reformer prototype developed in the project is evaluated. The reformer which was constructed for serving a 5 k W{sub e} fuel cell had a high performance with near 100 % methanol conversion and CO

  9. Hydrogenation of carbon dioxide for methanol production

    NARCIS (Netherlands)

    Ham, van der A.G.J.; Berg, van den H.; Benneker, A.; Simmelink, G.; Timmer, J.; Weerden, van S.

    2012-01-01

    A process for the hydrogenation of CO2 to methanol with a capacity of 10 kt/y methanol is designed in a systematic way. The challenge will be to obtain a process with a high net CO2 conversion. From initially four conceptual designs the most feasible is selected and designed in more detail. The feed

  10. Simple PVT Quantitative Method of Kr Under High Pure N2 Condition%高纯氮载气中Kr的简便PVT定量方法

    Institute of Scientific and Technical Information of China (English)

    李雪松; 张子斌; 韦冠一; 陈莉云; 翟利华

    2005-01-01

    A simple PVT quantitative method of Kr in the high pure N2 was studied. Pressure, volume and temperature of the sample gas were measured by three individual methods to obtain the sum sample with food uncertainty. The ratio of Kr/N2 could be measured by GAM400 quadrupole mass spectrometer. So the quantity of Kr could be calculated with the two measured data above. This method can be suited for quantitative analysis of other simple composed noble gas sample with high pure carrying gas.

  11. Experimental Evaluation of a Pt-based Heat Exchanger Methanol Reformer for a HTPEM Fuel Cell Stack

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen; Nielsen, Mads Pagh

    2008-01-01

    and automotive applications. Using a liquid hydrocarbon as e.g. methanol as the hydrogen carrier and reforming it to a hydrogen rich gas can solve some of these storage issues. The work presented here examines the use of a heat exchanger methanol reformer for use with a HTPEM fuel cell stack. Initial......Fuel cell systems running on pure hydrogen can efficiently produce electricity and heat for various applications, stationary and mobile. Storage volume can be problematic for stationary fuel cell systems with high run-time demands, but it is especially a challenge when dealing with mobile...

  12. The Methanol Miracle

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    Methanol already makes a good fuel for camp stoves and even for a few cars. But in the future,say botanist Arthur Nonomura and biochemist Andrew Benson,methanol may fuel an agricultural revolution in hot and dry regions of the world. When the researchers recently sprayed diluted solutions of methanol on crops at Nonomura’s Arizona farm,they found they could double yields in some cases and halve water consumption in others.

  13. Worm-Shape Pt Nanocrystals Grown on Nitrogen-Doped Low-Defect Graphene Sheets: Highly Efficient Electrocatalysts for Methanol Oxidation Reaction.

    Science.gov (United States)

    Huang, Huajie; Ma, Lulu; Tiwary, Chandra Sekhar; Jiang, Quanguo; Yin, Kuibo; Zhou, Wu; Ajayan, Pulickel M

    2016-12-27

    Although direct methanol fuel cell offers high energy use efficiency and low pollution emission, the lack of suitable electrode materials poses a great challenge to its commercial application. Herein, a facile and scalable approach is developed to fabricate a hybrid electrocatalyst consisting of strongly coupled worm-shape Pt nanocrystals and nitrogen-doped low-defect graphene (N-LDG) sheets. Interestingly, it is found that the formation of Pt nanoworms (NWs) is induced by the N atoms in the high-quality carbon matrix, which also allows the integration of their respective structural advantages and leads to a strong synergetic coupling effect. As a result, the obtained Pt NW/N-LDG catalyst exhibits an extremely high mass activity of 1283.1 mA mg(-1) toward methanol oxidation reaction, accompanied by reliable long-term stability and good antipoisoning ability, which are dramatically enhanced as compared with conventional Pt nanoparticle catalysts dispersed on undoped LDG, reduced graphene oxide, and commercial carbon black supports.

  14. Engineered high aspect ratio vertical nanotubes as a model system for the investigation of catalytic methanol synthesis over Cu/ZnO.

    Science.gov (United States)

    Güder, Firat; Frei, Elias; Kücükbayrak, Umut M; Menzel, Andreas; Thomann, Ralf; Luptak, Roman; Hollaender, Bernd; Krossing, Ingo; Zacharias, Margit

    2014-02-12

    Catalytically synthesized methanol from H2 and CO2 using porous Cu/ZnO aggregates is a promising, carbon neutral, and renewable alternative to replace fossil fuel based transport fuels. However, the absence of surface-engineered model systems to understand and improve the industrial Cu/ZnO catalyst poses a big technological gap in efforts to increase industrial methanol conversion efficiency. In this work, we report a novel process for the fabrication of patterned, vertically aligned high aspect ratio 1D nanostructures on Si that can be used as an engineered model catalyst. The proposed strategy employs near-field phase shift lithography (NF-PSL), deep reactive ion etching (DRIE), and atomic layer deposition (ALD) to pattern, etch, and coat Si wafers to produce high aspect ratio 1D nanostructures. Using this method, we produced a model system consisting of high aspect ratio Cu-decorated ZnO nanotubes (NTs) to investigate the morphological effects of ZnO catalyst support in comparison to the planar Cu/ZnO catalyst in terms of the catalytic reactions. The engineered catalysts performed 70 times better in activating CO2 than the industrial catalyst. In light of the obtained results, several important points are highlighted, and recommendations are made to achieve higher catalytic performance.

  15. Methanol Asinger's vision today

    CERN Document Server

    Bertau, Martin; Plass, Ludolf; Schmidt, Friedrich; Wernicke, Hans-Jürgen

    2014-01-01

    Methanol - The Chemical and Energy Feedstock of the Future offers a visionary yet unbiased view of methanol technology. Based on the groundbreaking 1986 publication ""Methanol"" by Friedrich Asinger, this book includes contributions by more than 40 experts from industry and academia. The authors and editors provide a comprehensive exposition of methanol chemistry and technology which is useful for a wide variety of scientists working in chemistry and energy related industries as well as academic researchers and even decision-makers and organisations concerned with the future of chemical and e

  16. The Methanol Economy Project

    Energy Technology Data Exchange (ETDEWEB)

    Olah, George [Univ. of Southern California, Los Angeles, CA (United States); Prakash, G. K. [Univ. of Southern California, Los Angeles, CA (United States)

    2014-02-01

    The Methanol Economy Project is based on the concept of replacing fossil fuels with methanol generated either from renewable resources or abundant natural (shale) gas. The full methanol cycle was investigated in this project, from production of methanol through bromination of methane, bireforming of methane to syngas, CO2 capture using supported amines, co-electrolysis of CO2 and water to formate and syngas, decomposition of formate to CO2 and H2, and use of formic acid in a direct formic acid fuel cell. Each of these projects achieved milestones and provided new insights into their respective fields.

  17. The microscopic structure of cold aqueous methanol mixtures

    Science.gov (United States)

    Požar, Martina; Kerasidou, Ariadni; Lovrinčević, Bernarda; Zoranić, Larisa; Mijaković, Marijana; Primorac, Tomislav; Sokolić, Franjo; Teboul, Victor; Perera, Aurélien

    2016-10-01

    The evolution of the micro-segregated structure of aqueous methanol mixtures, in the temperature range 300 K-120 K, is studied with computer simulations, from the static structural point of view. The structural heterogeneity of water is reinforced at lower temperatures, as witnessed by a pre-peak in the oxygen-oxygen structure factor. Water tends to form predominantly chain-like clusters at lower temperatures and smaller concentrations. Methanol domains have essentially the same chain-like cluster structure as the pure liquid at high concentrations and becomes monomeric at smaller ones. Concentration fluctuations decrease with temperature, leading to quasi-ideal Kirkwood-Buff integrals, despite the enhanced molecular interactions, which we interpret as the signature of non-interacting segregated water and methanol clusters. This study throws a new light on the nature of the micro-heterogeneous structure of this mixture: the domain segregation is essentially based on the appearance of linear water clusters, unlike other alcohol aqueous mixtures, such as with propanol or butanol, where the water domains are more bulky.

  18. Bimetallic PtAu superlattice arrays: Highly electroactive and durable catalyst for oxygen reduction and methanol oxidation reactions

    Science.gov (United States)

    Feng, Jiu-Ju; He, Li-Li; Fang, Rui; Wang, Qiao-Li; Yuan, Junhua; Wang, Ai-Jun

    2016-10-01

    Superlattice arrays, an important type of nanomaterials, have wide applications in catalysis, optic/electronics and energy storage for the synergetic effects determined by both individual metals and collective interactions. Herein, a simple one-pot solvothermal coreduction approach is developed for facile preparation of bimetallic PtAu alloyed superlattice arrays (PtAu SLAs) in oleylamine, with the assistance of urea via hydrogen bonding induced self-assembly. Urea is essential in morphology-controlled process and prevents PtAu nanoparticles from the disordered aggregation. The characterization and formation mechanism of PtAu SLAs are investigated in details. The as-synthesized hybrid nanocrystals exhibit enhanced electrocatalytic performances for oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR) in alkaline electrolyte in comparison with commercial Pt-C (50%, wt.%) and Pt black catalysts.

  19. Design and synthesis of Pd-MnO2 nanolamella-graphene composite as a high-performance multifunctional electrocatalyst towards formic acid and methanol oxidation.

    Science.gov (United States)

    Huang, Huajie; Wang, Xin

    2013-07-07

    One great challenge in the development of portable fuel cell systems is to explore novel electrocatalysts with better performance and lower costs. Here we report a facile strategy to fabricate a ternary nanocomposite based on Pd/MnO2 nanolamella-graphene sheets (Pd/MNL/GS) and demonstrate its application as a multifunctional catalyst for both the direct formic acid fuel cell (DFAFC) and direct methanol fuel cell (DMFC). The developed route rationally utilizes graphene as both a green reducing agent in the synthesis of MnO2 nanolamella and a superior supporting material for growing and supporting Pd nanoparticles (NPs). Whether for formic acid oxidation or methanol oxidation, the as-prepared Pd/MNL/GS hybrid has extremely large electrochemically active surface area (ECSA) values and exhibits significantly high forward peak current densities, both of which are nearly 3 times greater than those of the Pd/GS catalyst and 6 times the Pd/Vulcan XC-72 catalyst, revealing that metal Pd can be effectively utilized in the presence of promoter components (MNL and GS). Therefore, such a ternary composite with a sophisticated 2D configuration may bring new design opportunities of high-performance energy conversion devices in the future.

  20. Palladium Nanoparticles Supported on Nitrogen and Sulfur Dual-Doped Graphene as Highly Active Electrocatalysts for Formic Acid and Methanol Oxidation.

    Science.gov (United States)

    Zhang, Xin; Zhu, Jixin; Tiwary, Chandra Sekhar; Ma, Zhongyuan; Huang, Huajie; Zhang, Jianfeng; Lu, Zhiyong; Huang, Wei; Wu, Yuping

    2016-05-04

    Optimized designing of highly active electrocatalysts has been regarded as a critical point to the development of portable fuel cell systems with high power density. Here we report a facile and cost-effective strategy to synthesis of ultrafine Pd nanoparticles (NPs) supported on N and S dual-doped graphene (NS-G) nanosheets as multifunctional electrocatalysts for both direct formic acid fuel cell and direct methanol fuel cell. The incorporation of N and S atoms into graphene frameworks is achieved by a thermal treatment process, followed by the controlled growth of Pd NPs via a solvothermal approach. Owning to the unique structural features as well as the strong synergistic effects, the resulting Pd/NS-G hybrid exhibits outstanding electrocatalytic performance toward both formic acid and methanol electro-oxidation, such as higher anodic peak current densities and more exceptional catalytic stability than those of Pd/Vulcan XC-72R and Pd/undoped graphene catalysts. These findings open up new possibility in the construction of advanced Pd-based catalysts, which is conducive to solving the current bottlenecks of fuel cell technologies.

  1. High resolution infrared spectrum of the CD2 wagging band of methanol-D2 (CHD2OH) for the lowest lying torsional vibrational state (e0)

    Science.gov (United States)

    Mukhopadhyay, Indra

    2016-07-01

    This paper reports the analysis of the high resolution (0.0019 cm-1) Fourier transform infrared (FTIR) spectrum for asymmetrically deuterated methanol CHD2OH (methanol-D2) at a low temperature for the CD2 wagging band for the lowest lying trans-species (e0). In spite of the complexity and perturbation in the spectra, assignments were possible for the CD2 wagging band for a maximum K value of 10. In total, about 500 spectral lines have been assigned. Analysis of the spectral lines has been performed in terms of state dependent molecular parameters, Q-branch origins and asymmetry splitting. Assignments have been thoroughly confirmed using combination relations (see text). The catalogue of the assigned transition wavenumbers will help identification and prediction of far infrared (FIR) optically pumped CO2 lasers. The absorption lines close to the several 10R and 10P CO2 laser lines have also been identified. These should help experimentalists to optimize the power of the emission FIR laser lines and to predict new lines and should prove valuable as a laboratory support for interstellar detection in "Radio Astronomy". To our knowledge this is the first time such vibrational infrared (IR) high resolution study in CHD2OH is being performed.

  2. Investigating chemical changes during shelf-life of thermal and high-pressure high-temperature sterilised carrot purees: A 'fingerprinting kinetics' approach.

    Science.gov (United States)

    Kebede, Biniam T; Grauwet, Tara; Palmers, Stijn; Michiels, Chris; Hendrickx, Marc; Van Loey, Ann

    2015-10-15

    This work investigates chemical changes during shelf-life of thermally and high pressure high temperature (HPHT) sterilised carrot purees using a 'fingerprinting kinetics' approach. Fingerprinting enabled selection of Strecker aldehydes, terpenes, phenylpropanoids, fatty acid derivatives and carotenoid degradation products as volatiles clearly changing during shelf-life. Next, kinetic modelling of these volatiles was performed to compare their reaction kinetics during storage in differently sterilised samples. Immediately after processing, the Strecker aldehydes were detected at higher levels in thermally sterilised samples. During storage, the compounds increased at a comparable rate in thermally and HPHT processed samples. In contrast, immediately after processing, most of the naturally occurring terpenes and phenylpropanoids were better preserved in HPHT treated samples. Nevertheless, by the end of storage, the concentration of these compounds decreased to almost the same level in both thermal and HPHT samples (with a higher degradation rate in HPHT samples).

  3. Sorption phenomena of methanol on heat treated coal; Netsushori wo hodokoshita sekitan no methanol kyuchaku tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Yasuda, H.; Kaiho, M.; Yamada, O.; Soneda, Y.; Kobayashi, M.; Makino, M. [National Institute for Resources and Environment, Tsukuba (Japan)

    1996-10-28

    Experiments were carried out to learn methanol sorption characteristics of heat-treated coal. When Taiheiyo coal is heat-treated at 125{degree}C, performed with a first methanol adsorption at 25{degree}C, and then desorption at 25{degree}C, a site with strong interaction with methanol and a site with relatively weak interaction are generated in test samples. A small amount of methanol remains in both sites. Then, when the methanol is desorbed at as low temperature as 70{degree}C, the methanol in the site with strong interaction remains as it has existed therein, but the methanol in the site with relatively weak interaction desorbs partially, hence the adsorption amount in a second adsorption at 25{degree}C increases. However, when desorption is performed at as high temperature as 125{degree}C, the methanol in the site with strong interaction also desorbs, resulting in increased adsorption heat in the second adsorption. The adsorption velocity drops, however. Existence of methanol in a site with strong interaction affects the adsorption velocity, but no effect is given by methanol in a site with weak interaction. 3 refs., 4 figs.

  4. Switching from high doses of pure μ-opioid agonists to transdermal buprenorphine in patients with cancer

    DEFF Research Database (Denmark)

    Lundorff, Lena; Sjøgren, Per; Hansen, Ole Bo

    2013-01-01

    with moderate-to-severe cancer pain satisfactorily controlled. SETTING: Patients were switched from the usual pure agonist to TD buprenorphine and were titrated to a stable dose. The assessments were: 1) daily self-assessment of pain intensity, numbers of rescue medications, and pain interference with sleep; 2...

  5. Methanol partial oxidation reformer

    Science.gov (United States)

    Ahmed, Shabbir; Kumar, Romesh; Krumpelt, Michael

    1999-01-01

    A partial oxidation reformer comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell.

  6. The Catalysis of NAD+ on Methanol Anode Oxidation Electrode for Direct Methanol Fuel Cell

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ping; PAN Mu; YUAN Run-zhang

    2004-01-01

    A tentative idea of developing a liquid-catalytic system on methanol anode oxidation was proposed by analyzing the characteristics of methanol anode oxidation in direct methanol fuel cell. The kinetics of methanol oxidation at a glassy carbon electrode in the presence of nicotinamide adenine dinucleotide (NAD+) was investigated. It is found that the current density of methanol oxidation increases greatly and the electrochemical reaction impedance reduces obviously in the presence of NAD+ compared with those in the absence of NAD+. The catalytic activity of NAD+ is sensitive to temperature. When the temperature preponderates over 45℃, NAD+ is out of function of catalysis for methanol oxidation, which is probably due to the denaturation of NAD+ at a relatively high temperature.

  7. Methanol production from Eucalyptus wood chips. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Fishkind, H.H.

    1982-06-01

    This feasibility study includes all phases of methanol production from seedling to delivery of finished methanol. The study examines: production of 55 million, high quality, Eucalyptus seedlings through tissue culture; establishment of a Eucalyptus energy plantation on approximately 70,000 acres; engineering for a 100 million gallon-per-day methanol production facility; potential environmental impacts of the whole project; safety and health aspects of producing and using methanol; and development of site specific cost estimates.

  8. Visual processing in pure alexia

    DEFF Research Database (Denmark)

    Starrfelt, Randi; Habekost, Thomas; Gerlach, Christian

    2010-01-01

    Whether pure alexia is a selective disorder that affects reading only, or if it reflects a more general visual disturbance, is highly debated. We have investigated the selectivity of visual deficits in a pure alexic patient (NN) using a combination of psychophysical measures, mathematical modelling...

  9. The fast Z-scan method for studying working catalytic reactors with high energy X-ray diffraction: ZSM-5 in the methanol to gasoline process.

    Science.gov (United States)

    Wragg, David S; Bleken, Francesca L; O'Brien, Matthew G; Di Michiel, Marco; Fjellvåg, Helmer; Olsbye, Unni

    2013-06-14

    The methanol to gasoline process over the zeolite catalyst ZSM-5 in a lab-sized reactor bed (4 mm diameter) has been studied in operando with high energy synchrotron X-ray diffraction. The fast z-scan method was used, scanning the reactor repeatedly and at speed through the X-ray beam. The X-ray diffraction data were processed using high throughput parametric Rietveld refinement to obtain real structural parameters. The diffraction data show only very subtle changes during the process and this allows us to demonstrate the combination of very large data volumes with parametric Rietveld methods to study weak features of the data. The different possible data treatment methodologies are discussed in detail and their effects on the results obtained are demonstrated. The trends in unit cell volume, zeolite channel occupancy and crystallite strain indicate that more or larger reaction intermediates are present close to the reactor outlet.

  10. Experimental Characterization of the Poisoning Effects of Methanol-Based Reformate Impurities on a PBI-Based High Temperature PEM Fuel Cell

    DEFF Research Database (Denmark)

    Araya, Samuel Simon; Andreasen, Søren Juhl; Kær, Søren Knudsen

    2012-01-01

    surface area is investigated by means of impedance spectroscopy. The concentrations in the anode feed gas of all impurities, unconverted methanol-water vapor mixture, CO and CO2 were varied along with current density according to a multilevel factorial design of experiments. Results show that all......In this work the effects of reformate gas impurities on a H3PO4-doped polybenzimidazole (PBI) membrane-based high temperature proton exchange membrane fuel cell (HT-PEMFC) are studied. A unit cell assembly with a BASF Celtec®-P2100 high temperature membrane electrode assembly (MEA) of 45 cm2 active...... the impurities degrade the performance, with CO being the most degrading agent and CO2 the least. The factorial analysis shows that there is interdependence among the effects of the different factors considered. This interdependence suggests, for example, that tolerances to concentrations of CO above 2% may...

  11. Chirally Pure Prodrugs and Their Converting Enzymes Lead to High Supersaturation and Rapid Transcellular Permeation of Benzodiazepines.

    Science.gov (United States)

    Kapoor, Mamta; Cheryala, Narsihmulu; Rautiola, Davin; Georg, Gunda I; Cloyd, James C; Siegel, Ronald A

    2016-08-01

    Water-soluble prodrugs can be rapidly converted by enzymes to hydrophobic drugs, whose aqueous thermodynamic solubilities are low, but are maintained in aqueous solution at supersaturated concentrations due to slow precipitation kinetics. Recently, we investigated avizafone (AVF) in combination with Aspergillus oryzae protease as a prodrug/enzyme system intended to produce supersaturated diazepam (DZP). Several fold enhancement of permeation of supersaturated DZP across Madin-Darby canine kidney II-wild type (MDCKII-wt) monolayers was observed, compared to saturated DZP solutions. However, prodrug conversion was incomplete, putatively due to partial racemization of AVF and stereoselectivity of A oryzae protease. Here we report synthesis of chirally pure AVF, and demonstrate complete conversion to supersaturated DZP followed by complete DZP permeation at enhanced rates across MDCKII-wt cell monolayers. We also synthesized, for the first time, a chirally pure prodrug of midazolam (MDZ-pro) and carried out the same sequence of studies. A oryzae protease was identified as a benign and efficient activating enzyme for MDZ-pro. The MDZ-pro/A oryzae protease system showed greater than 25-fold increase in absorption rate of MDZ across MDCKII-wt monolayers, compared to saturated MDZ. Such chirally pure prodrug/enzyme systems are promising candidates for efficient intranasal delivery of benzodiazepine drugs used in the treatment of seizure emergencies. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  12. High-temperature hydrogenation of pure and silver-decorated titanate nanotubes to increase their solar absorbance for photocatalytic applications

    Energy Technology Data Exchange (ETDEWEB)

    Plodinec, Milivoj [Ruđer Bošković Institute, Bijenička 54, HR-1002 Zagreb (Croatia); Gajović, Andreja, E-mail: gajovic@irb.hr [Ruđer Bošković Institute, Bijenička 54, HR-1002 Zagreb (Croatia); Jakša, Gregor; Žagar, Kristina; Čeh, Miran [Institute Jožef Stefan, Jamova 39, 1000 Ljubljana (Slovenia)

    2014-04-05

    Graphical abstract: The aim of the work is to study how annealing in a reducing atmosphere of titanate nanotubes (TiNT) and Ag decorated titanate nanotubes (TiNT@Ag) influenced on their structure, morphology, phase transitions, UV–ViS-NIR absorbance and photocatalytic activity. An increase of photocatalytic activity after a heat treatment in a reducing atmosphere was observed in the TiNT and TiNT@Ag. We found that the hydrogenated TiNT@Ag samples (TiNT@Ag-HA) had a two-times higher photodegradation impact on the caffeine than the TiNT samples, which is a consequence of the increased absorption of visible light and the synergetic effects between the silver and the TiO{sub 2} nanoparticles that increase the efficiency of the formation of electron–hole pairs and the charge transfer to the surface of the nanoparticles. -- Highlights: • Titanate nanotubes with and without Ag nanoparticles were hydrogenated at 550 °C. • TiO{sub 2} nanostructures obtained by hydrogenation have core–shell structure. • Hydrogenated samples show absorption in the visible spectral region. • Hydrogenated Ag decorated sample show stronger absorption in visible than in UV. • Photocatalytic efficiency is improved by hydrogenation and by Ag nanoparticles. -- Abstract: Titanate nanotubes (TiNTs) and silver-decorated titanate nanotubes (TiNTs@Ag) were synthesized using the hydrothermal method. In the decorated nanotubes the silver particles were obtained by the photoreduction of AgNO{sub 3} under UV light. Pure and Ag-decorated nanotubes were high-temperature heat treated at 550 °C in a hydrogen atmosphere and the “core–shell”-structured TiO{sub 2} nanoparticles were formed. For the structural characterization of all the titanate nanostructures we used conventional and analytical transmission electron microscopy (TEM) techniques, X-ray diffraction (XRD) and Raman spectroscopy. The Ag-decorated titanate nanostructures were additionally studied by X-ray photo

  13. Dietary methanol and autism.

    Science.gov (United States)

    Walton, Ralph G; Monte, Woodrow C

    2015-10-01

    The authors sought to establish whether maternal dietary methanol during pregnancy was a factor in the etiology of autism spectrum disorders. A seven item questionnaire was given to women who had given birth to at least one child after 1984. The subjects were solicited from a large primary care practice and several internet sites and separated into two groups - mothers who had given birth to a child with autism and those who had not. Average weekly methanol consumption was calculated based on questionnaire responses. 550 questionnaires were completed by women who gave birth to a non-autistic child. On average these women consumed 66.71mg. of methanol weekly. 161 questionnaires were completed by women who had given birth to an autistic child. The average estimated weekly methanol consumption for this group was 142.31mg. Based on the results of the Wilcoxon rank sum-test, we see a significant difference between the reported methanol consumption rates of the two groups. This study suggests that women who have given birth to an autistic child are likely to have had higher intake of dietary sources of methanol than women who have not. Further investigation of a possible link of dietary methanol to autism is clearly warranted.

  14. Methanol dehydration on carbon-based acid catalysts

    OpenAIRE

    Valero-Romero, Mª José; Calvo-Muñoz, Elisa Mª; Ruiz-Rosas, Ramiro; Rodríguez-Mirasol, José; Cordero, Tomás

    2013-01-01

    Methanol dehydration to produce dimethyl ether (DME) is an interesting process for the chemical industry since DME is an important intermediate and a promising clean alternative fuel for diesel engines. Pure or modified γ-aluminas (γ-Al2O3) and zeolites are often used as catalysts for this reaction. However, these materials usually yield non desirable hydrocarbons and undergo fast deactivation. In this work, we study the catalytic conversion of methanol over an acid carbon catalyst obtaine...

  15. Thermal Effusivity Measurement of Virgin Coconut Oil-Methanol Mixtures using Photoacoustic Technique

    Directory of Open Access Journals (Sweden)

    Firas K.M. Al-asfoor

    2008-01-01

    Full Text Available Thermal effusivity of virgin coconut oil-methanol mixtures were measured using open photoacoustic cell technique. The samples were prepared by simply mixing virgin coconut oil and methanol using similar procedure applied for preparation of biodisel. Thermal effusivity of the sample was obtained by fitting the experimental data of photoacoustic amplitude signal to the expression of photoacoustic signal as a function of chopping frequency. Thermal effusivity of mixtures decrease between 0.0851 W s1/2 K-1 cm-2 (pure virgin coconut oil and 0.0644 W s1/2 K-1 cm-2 (pure methanol with the increasing of methanol in the mixture.

  16. Transesterification of waste vegetable oil under pulse sonication using ethanol, methanol and ethanol–methanol mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Guerra, Edith; Gude, Veera Gnaneswar, E-mail: gude@cee.msstate.edu

    2014-12-15

    Highlights: • Pulse sonication effect on transesterification of waste vegetable oil was studied. • Effects of ethanol, methanol, and alcohol mixtures on FAMEs yield were evaluated. • Effect of ultrasonic intensity, power density, and its output rates were evaluated. • Alcohol mixtures resulted in higher biodiesel yields due to better solubility. - Abstract: This study reports on the effects of direct pulse sonication and the type of alcohol (methanol and ethanol) on the transesterification reaction of waste vegetable oil without any external heating or mechanical mixing. Biodiesel yields and optimum process conditions for the transesterification reaction involving ethanol, methanol, and ethanol–methanol mixtures were evaluated. The effects of ultrasonic power densities (by varying sample volumes), power output rates (in W), and ultrasonic intensities (by varying the reactor size) were studied for transesterification reaction with ethanol, methanol and ethanol–methanol (50%-50%) mixtures. The optimum process conditions for ethanol or methanol based transesterification reaction of waste vegetable oil were determined as: 9:1 alcohol to oil ratio, 1% wt. catalyst amount, 1–2 min reaction time at a power output rate between 75 and 150 W. It was shown that the transesterification reactions using ethanol–methanol mixtures resulted in biodiesel yields as high as >99% at lower power density and ultrasound intensity when compared to ethanol or methanol based transesterification reactions.

  17. 浅述我国甲醇汽油的应用发展%Overview of Application Development of Methanol Gasoline

    Institute of Scientific and Technical Information of China (English)

    鲁彪

    2012-01-01

    甲醇燃料是目前公认的一种燃油代用燃料。在比较甲醇和汽油的物化特性的基础上,分析了甲醇作为汽油代用燃料的优点和发展趋势,分析了甲醇汽油的安全性。介绍了我国甲醇汽油的研究应用和在高海拔条件的独特优势,及车用燃料甲醇在我国的发展前景。%Methanol fuel is recognized as a substitute fuel. Based on the comparison of the properties of methanol and pure gasoline, the paper analyzes the advantage and development trend of Methanol gasoline alternative fuel, and the Security of Methanol gasoline. This paper introduces the application and study of methanol gasoline, the unique advantages of methanol gasoline in high altitude conditions, and develop- ment Prospect of fuel methanol for vehicles in China.

  18. High resolution synchrotron radiation Fourier transform infrared spectrum of the COH-bending mode in methanol-D1 (CH2DOH)

    Science.gov (United States)

    Mukhopadhyay, Indra; Billinghurst, B. E.

    2017-09-01

    In this work the high resolution synchrotron radiation Fourier transform spectrum in the range 1180-1300 cm-1 corresponding to the COH-bending vibrational mode has been recorded and analyzed. The spectrum shows a structure analogous to a parallel band. Since the COH bending motion is one of the main contributors to the asymmetry in the torsional hindering potential barrier, the torsional barrier height in the excited state is expected to be quite different from that of the ground state. This makes the spectrum to spread over a wide region. Although the spectrum corresponding to the P- and R-branch looks very complicated, the Q-branches are well resolved and can be identified without much difficulty. It was possible to assign the spectra for K = 0 to 10 for the trans- (e0) species. The interesting feature of the spectra is the absence of the lines for two other lower lying gauche symmetry species e1 and o1. The spectra due to any perpendicular transitions were absent as well. However some weak c-type transitions from gauche states (o1 and e1) in the ground state to the trans-species (e0) in the COD bending mode for low K-values ΔK = 0 have been seen to be present in the spectra. These along with similar transitions for the OCD vibrational band are under investigation and the results will be communicated elsewhere. In the present work, analysis of the spectrum has been carried out to obtain precise term values and molecular parameters in the excited COH-bending state for the trans-species. The results will be shown valuable to assign similar spectra for the methanol-D2. This work represents the first reported high resolution study of this illusive vibrational mode in methanol-D1.

  19. Methanol Cannon Demonstrations Revisited.

    Science.gov (United States)

    Dolson, David A.; And Others

    1995-01-01

    Describes two variations on the traditional methanol cannon demonstration. The first variation is a chain reaction using real metal chains. The second example involves using easily available components to produce sequential explosions that can be musical in nature. (AIM)

  20. Experimental evaluation of a Pt based heat exchanger methanol reformer for a HTPEM fuel cell

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Nielsen, Mads Pagh; Kær, Søren Knudsen

    2007-01-01

    .g. methanol. A hydrocarbon as methanol can be derived from e.g. biomass and be used directly in a PEM fuel cell, but with a poor performance and often complicated water management system. Another way of using methanol in a fuel cell is by steam reforming it over a catalyst to hydrogen : CH3OH+H2O CO2 + 3H......2. Included in this reaction is the decomposition of methanol, which produces CO : CH3OH CO + 2H2 , The CO can be removed by adding extra water to the gas by a water-gas-shift: CO + H2O CO2 + H2. The hydrogen can then be used in a fuel cell with a much better performance than the DMFC. Many...... Nafion based low temperature PEM fuel cells are intolerant to CO in the anode gas, and require very pure hydrogen with only up to 100 ppm CO or even lower. Another type of PEM fuel cells, the PBI based high temperature PEM operates at high temperatures (160-180oC), and has a much higher tolerance of CO...

  1. Transesterification of waste vegetable oil under pulse sonication using ethanol, methanol and ethanol-methanol mixtures.

    Science.gov (United States)

    Martinez-Guerra, Edith; Gude, Veera Gnaneswar

    2014-12-01

    This study reports on the effects of direct pulse sonication and the type of alcohol (methanol and ethanol) on the transesterification reaction of waste vegetable oil without any external heating or mechanical mixing. Biodiesel yields and optimum process conditions for the transesterification reaction involving ethanol, methanol, and ethanol-methanol mixtures were evaluated. The effects of ultrasonic power densities (by varying sample volumes), power output rates (in W), and ultrasonic intensities (by varying the reactor size) were studied for transesterification reaction with ethanol, methanol and ethanol-methanol (50%-50%) mixtures. The optimum process conditions for ethanol or methanol based transesterification reaction of waste vegetable oil were determined as: 9:1 alcohol to oil ratio, 1% wt. catalyst amount, 1-2 min reaction time at a power output rate between 75 and 150 W. It was shown that the transesterification reactions using ethanol-methanol mixtures resulted in biodiesel yields as high as >99% at lower power density and ultrasound intensity when compared to ethanol or methanol based transesterification reactions.

  2. Solubility of CO2 in Methanol, 1-Octyl-3-methylimidazolium Bis(trifluoromethylsulfonyl)imide, and Their Mixtures

    Institute of Scientific and Technical Information of China (English)

    LEI Zhigang; ZHANG Benfeng; ZHU Jiqin; GONG Wanfu; L(U) Jianning; LI Yansheng

    2013-01-01

    Solubility data of carbon dioxide (CO2) (1) in methanol (2),1-octyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([omim]+[Tf2N]-) (3),and their mixtures (w3 =0.2,0.5,and 0.8) at temperatures 313.2 and 333.2 K and pressures up to 7.0 MPa were measured by a high-pressure view-cell technique.The solubility of CO2 in methanol (w3 =0),[omim]+[Tf2N]-(w3 =1.0) and their mixtures follows the order of (w3=0)<(w3 =0.2)<(w3 =0.5)<(w3 =0.8)<(w3 =1.0) at the same temperature and pressure,while the magnitude of Henry's constants follows the reverse order at a given temperature,which is consistent with the COSMO-RS (conductor-like screening for real solvents) calculation.The solubility data of CO2 in methanol and [omim]+[Tf2N]-are correlated with the Peng-Robinson equation of state,and the solubility of CO2 in the mixtures of methanol and [omim]+[Tf2N]-can be well predicted based on the mole fraction average of methanol and [omim]+[Tf2N]-over the solubility of CO2 in pure methanol and [omim]+[Tf2N]-.The mixtures of methanol and [omim] [Tf2N]-may be used as physical solvents for capturing CO2 with high partial pressures since they combine the advantages of organic solvents and ionic liquids.

  3. Use of ion-molecule reactions and methanol addition to improve arsenic determination in high chlorine food samples by DRC-ICP-MS.

    Science.gov (United States)

    Guo, Wei; Hu, Shenghong; Li, Xiaofang; Zhao, Jian; Jin, Shesheng; Liu, Wenjuan; Zhang, Hongfei

    2011-05-15

    Direct determination of trace arsenic in high chlorine food samples by ICP-MS is complicated by the presence of ArCl(+) interferences, and the high first ionization energy of As (9.81 eV) also results in low analytical sensitivity in ICP-MS. In this work, two strategies based on ion-molecule reactions were successfully used to eliminate ArCl spectral interference in a dynamic reaction cell (DRC). The interference ion ((40)Ar(35)Cl(+)) was directly removed by the reaction with methane gas, and the background signal was reduced by up to 100-fold at m/z 75. Alternatively, by using molecule oxygen as the reaction gas, (75)As(+) was effectively converted to (75)As(16)O(+) that could be detected at m/z 91 where the background is low. The poor signal intensity of As or AsO was improved 3-4 times by addition of 4% methanol in the analyzed solutions. The limit of quantitation (LOQ) for (75)As (CH(4)-DRC method) and (75)As(16)O (O(2)-DRC method) was 0.8 and 0.3 ng g(-1) and the analytical results of seaweed and yellow croaker standard reference materials were in good agreement with the certified values. As the routine arsenic monitoring method in our laboratory, it was applied to the accuracy determination of 119 high chlorine food samples from eight different markets of Beijing.

  4. Facile Isolation of Adsorbent-Free Long and Highly-Pure Chirality-Selected Semiconducting Single-Walled Carbon Nanotubes Using A Hydrogen-bonding Supramolecular Polymer

    Science.gov (United States)

    Toshimitsu, Fumiyuki; Nakashima, Naotoshi

    2015-12-01

    The ideal form of semiconducting-single-walled carbon nanotubes (sem-SWNTs) for science and technology is long, defect-free, chirality pure and chemically pure isolated narrow diameter tubes. While various techniques to solubilize and purify sem-SWNTs have been developed, many of them targeted only the chiral- or chemically-purity while sacrificing the sem-SWNT intrinsic structural identities by applying strong ultra-sonication and/or chemical modifications. Toward the ultimate purification of the sem-SWNTs, here we report a mild-conditioned extraction of the sem-SWNTs using removable supramolecular hydrogen-bonding polymers (HBPs) that are composed of dicarboxylic- or diaminopyridyl-fluorenes with ~70%-(8,6)SWNT selective extraction. Replacing conventional strong sonication techniques by a simple shaking using HPBs was found to provide long sem-SWNTs (>2.0 μm) with a very high D/G ratio, which was determined by atomic force microscopy observations. The HBPs were readily removed from the nanotube surfaces by an outer stimulus, such as a change in the solvent polarities, to provide chemically pure (8,6)-enriched sem-SWNTs. We also describe molecular mechanics calculations to propose possible structures for the HBP-wrapped sem-SWNTs, furthermore, the mechanism of the chiral selectivity for the sorted sem-SWNTs is well explained by the relationship between the molecular surface area and mass of the HBP/SWNT composites.

  5. Hydrodynamic modeling of a pure-glue initial scenario in high-energy hadron and heavy-ion collisions

    CERN Document Server

    Vovchenko, V; Niemi, H; Karpenko, Iu A; Gorenstein, M I; Satarov, L M; Mishustin, I N; Kämpfer, B; Stoecker, H

    2016-01-01

    Partonic matter produced in the early stage of ultrarelativistic nucleus-nucleus collisions is assumed to be composed mainly of gluons, and quarks and antiquarks are produced at later times. The comparable hydrodynamic simulations of heavy-ion collisions for (2+1)-flavor and Yang-Mills equations of state performed by using three different hydrodynamic codes are presented. Assuming slow chemical equilibration of quarks, the spectra and elliptic flows of thermal dileptons and photons are calculated for central Pb+Pb collisions at the LHC energy of $\\sqrt{s_{_{\\rm NN}}} = 2.76$ TeV. It is shown that a suppression of quarks at early times leads to a significant reduction of the yield of the thermal dileptons, but only to a rather modest suppression of the $p_T$-distribution of direct photons. It is demonstrated that an enhancement of photon and dilepton elliptic flows might serve as a promising signature of the pure-glue initial state. Calculations based on Bjorken hydrodynamics suggest that collisions of small s...

  6. Melt layer erosion of pure and lanthanum doped tungsten under VDE-like high heat flux loads

    Science.gov (United States)

    Yuan, Y.; Greuner, H.; Böswirth, B.; Luo, G.-N.; Fu, B. Q.; Xu, H. Y.; Liu, W.

    2013-07-01

    Heat loads expected for VDEs in ITER were applied in the neutral beam facility GLADIS at IPP Garching. Several ˜3 mm thick rolled pure W and W-1 wt% La2O3 plates were exposed to pulsed hydrogen beams with a central heat flux of 23 MW/m2 for 1.5-1.8 s. The melting thresholds are determined, and melt layer motion as well as material structure evolutions are shown. The melting thresholds of the two W grades are very close in this experimental setup. Lots of big bubbles with diameters from several μm to several 10 μm in the re-solidified layer of W were observed and they spread deeper with increasing heat flux. However, for W-1 wt% La2O3, no big bubbles were found in the corrugated melt layer. The underlying mechanisms referred to the melt layer motion and bubble issues are tentatively discussed based on comparison of the erosion characteristics between the two W grades.

  7. Melt layer erosion of pure and lanthanum doped tungsten under VDE-like high heat flux loads

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Y., E-mail: yuanyue08@mails.tsinghua.edu.cn [Department of Material Science and Engineering, Tsinghua University, Haidian District, Beijing 100084 (China); Greuner, H.; Böswirth, B. [Max-Planck-Institut für Plasmaphysik, EURATOM Association, 85748 Garching (Germany); Luo, G.-N. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Fu, B.Q.; Xu, H.Y. [Department of Material Science and Engineering, Tsinghua University, Haidian District, Beijing 100084 (China); Liu, W., E-mail: liuw@mail.tsinghua.edu.cn [Department of Material Science and Engineering, Tsinghua University, Haidian District, Beijing 100084 (China)

    2013-07-15

    Heat loads expected for VDEs in ITER were applied in the neutral beam facility GLADIS at IPP Garching. Several ∼3 mm thick rolled pure W and W–1 wt% La{sub 2}O{sub 3} plates were exposed to pulsed hydrogen beams with a central heat flux of 23 MW/m{sup 2} for 1.5–1.8 s. The melting thresholds are determined, and melt layer motion as well as material structure evolutions are shown. The melting thresholds of the two W grades are very close in this experimental setup. Lots of big bubbles with diameters from several μm to several 10 μm in the re-solidified layer of W were observed and they spread deeper with increasing heat flux. However, for W–1 wt% La{sub 2}O{sub 3}, no big bubbles were found in the corrugated melt layer. The underlying mechanisms referred to the melt layer motion and bubble issues are tentatively discussed based on comparison of the erosion characteristics between the two W grades.

  8. Highly efficient multilayer organic pure blue light emitting diodes with substituted carbazoles compounds in the emitting layer

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, A [Laboratoire de Physique des Lasers (LPL, CNRS), Institut Galilee, Universite Paris 13, 93430 Villetaneuse (France); Chenais, S [Laboratoire de Physique des Lasers (LPL, CNRS), Institut Galilee, Universite Paris 13, 93430 Villetaneuse (France); Forget, S [Laboratoire de Physique des Lasers (LPL, CNRS), Institut Galilee, Universite Paris 13, 93430 Villetaneuse (France); Castex, M-C [Laboratoire de Physique des Lasers (LPL, CNRS), Institut Galilee, Universite Paris 13, 93430 Villetaneuse (France); Ades, D [Biomateriaux et Polymeres de Specialite (BPS/B2OA, CNRS), Institut Galilee, Universite Paris 13, Villetaneuse/Faculte de Medecine Lariboisiere-St Louis, Universite Paris 7, 75010 Paris (France); Siove, A [Biomateriaux et Polymeres de Specialite (BPS/B2OA, CNRS), Institut Galilee, Universite Paris 13, Villetaneuse/Faculte de Medecine Lariboisiere-St Louis, Universite Paris 7, 75010 Paris (France); Denis, C [Laboratoire Cellules et Composants, CEA/LITEN/DSEN, CEA Saclay, 91191 Gif-sur-Yvette (France); Maisse, P [Laboratoire Cellules et Composants, CEA/LITEN/DSEN, CEA Saclay, 91191 Gif-sur-Yvette (France); Geffroy, B [Laboratoire Cellules et Composants, CEA/LITEN/DSEN, CEA Saclay, 91191 Gif-sur-Yvette (France)

    2006-03-07

    Bright blue organic light-emitting diodes (OLEDs) based on 1, 4, 5, 8, N-pentamethylcarbazole (PMC) and on dimer of N-ethylcarbazole (N, N'-diethyl-3, 3'-bicarbazyl) (DEC) as emitting layers or as dopants in a 4, 4'-bis(2, 2'-diphenylvinyl)-1, 1'-biphenyl (DPVBi) matrix are described. Pure blue light with the CIE coordinates (x = 0.153, y = 0.100), electroluminescence efficiency {eta}{sub EL} of 0.4 cd A{sup -1}, external quantum efficiency {eta}{sub ext} of 0.6% and luminance L of 236 cd m{sup -2} (at 60 mA cm{sup -2}) were obtained with PMC as an emitter and the 2, 9-dimethyl-4, 7-diphenyl-1, 10-phenantroline (BCP) as a hole-blocking material in five-layer emitting devices. The highest efficiencies {eta}{sub EL} of 4.7 cd A{sup -1} and {eta}{sub ext} = 3.3% were obtained with a four-layer structure and a DPVBi DEC-doped active layer (CIE coordinates x = 0.158, y = 0.169, {lambda}{sub peak} = 456 nm). The {eta}{sub ext} value is one the highest reported at this wavelength for blue OLEDs and is related to an internal quantum efficiency up to 20%.

  9. Highly efficient multilayer organic pure blue light emitting diodes with substituted carbazoles compounds in the emitting layer

    Science.gov (United States)

    Fischer, A.; Chénais, S.; Forget, S.; Castex, M.-C.; Adès, D.; Siove, A.; Denis, C.; Maisse, P.; Geffroy, B.

    2006-03-01

    Bright blue organic light-emitting diodes (OLEDs) based on 1, 4, 5, 8, N-pentamethylcarbazole (PMC) and on dimer of N-ethylcarbazole (N, N'-diethyl-3, 3'-bicarbazyl) (DEC) as emitting layers or as dopants in a 4, 4'-bis(2, 2'-diphenylvinyl)-1, 1'-biphenyl (DPVBi) matrix are described. Pure blue light with the CIE coordinates (x = 0.153, y = 0.100), electroluminescence efficiency ηEL of 0.4 cd A-1, external quantum efficiency ηext of 0.6% and luminance L of 236 cd m-2 (at 60 mA cm-2) were obtained with PMC as an emitter and the 2, 9-dimethyl-4, 7-diphenyl-1, 10-phenantroline (BCP) as a hole-blocking material in five-layer emitting devices. The highest efficiencies ηEL of 4.7 cd A-1 and ηext = 3.3% were obtained with a four-layer structure and a DPVBi DEC-doped active layer (CIE coordinates x = 0.158, y = 0.169, λpeak = 456 nm). The ηext value is one the highest reported at this wavelength for blue OLEDs and is related to an internal quantum efficiency up to 20%.

  10. Highly efficient multilayer organic pure-blue-light emitting diodes with substituted carbazoles compounds in the emitting layer

    CERN Document Server

    Fischer, A; Chenais, S; Castex, M C; Siove, A; Ades, D; Geffroy, B; Denis, C; Maisse, P; Fischer, Alexis; Forget, Sebastien; Chenais, Sebastien; Castex, Marie-Claude; Siove, Alain; Ades, Dominique; Geffroy, Bernard; Denis, Christine; Maisse, Pascal

    2006-01-01

    Bright blue organic light-emitting diodes (OLEDs) based on 1,4,5,8,N-pentamethylcarbazole (PMC) and on dimer of N-ethylcarbazole (N,N'-diethyl-3,3'-bicarbazyl) (DEC) as emitting layers or as dopants in a 4,4'-bis(2,2'-diphenylvinyl)-1,1'-biphenyl (DPVBi) matrix are described. Pure blue-light with the C.I.E. coordinates x = 0.153 y = 0.100, electroluminescence efficiency \\eta_{EL} of 0.4 cd/A, external quantum efficiency \\eta_{ext.} of 0.6% and luminance L of 236 cd/m2 (at 60 mA/cm2) were obtained with PMC as an emitter and the 2,9-dimethyl-4,7-diphenyl-1,10-phenantroline (BCP) as a hole-blocking material in five-layer emitting devices. The highest efficiencies \\eta_{EL.} of 4.7 cd/A, and \\eta_{ext} = 3.3% were obtained with a four-layer structure and a DPVBi DEC-doped active layer (CIE coordinates x = 0.158, y=0.169, \\lambda_{peak} = 456 nm). The \\eta_{ext.} value is one the highest reported at this wavelength for blue OLEDs and is related to an internal quantum efficiency up to 20%.

  11. High resolution optical spectroscopy in isotopically-pure Si using radioactive isotopes: towards a re-evaluation of deep centres

    CERN Multimedia

    2008-01-01

    Deep centres in silicon have been studied in great detail over the last 50 years and much progress has been made in the understanding and control of impurities in this material. Much of this effort has been focussed on the problems of metallic impurities such as Fe, Ag, Cu and Au. These are impurities that diffuse quickly into the crystal and hamper device performance. Although the understanding of these impurity centres in Si is widely thought to be "solved" recent experiments with isotopically-pure Si are disproving long-held results and are opening up new perspectives on the constitutent nature of deep centres in Si. In particular, there is new evidence to show that the family of Cu, Ag and Au may all show essentially the same behaviour by forming a cluster of $\\textbf{any four atoms}$ of these elements. This has been established for Cu and Ag through the use of different stable isotopes in the preparation of samples, but the case of Au remains unproven since there is only one stable Au isotope. In this pr...

  12. Origin of low temperature deactivation of Ni5Ga3 nanoparticles as catalyst for methanol synthesis

    DEFF Research Database (Denmark)

    Gardini, Diego; Sharafutdinov, Irek; Damsgaard, Christian Danvad

    is subsequently increased, suggesting the presence of carbon containing species blocking the active sites of the alloy nanoparticles (Figure 1). Carbon deposition has furthermore been investigated by temperature programmed oxidation (TPO) of a deactivated catalyst in a fixed-bed reactor connected to a mass......-Ga alloys as active catalysts for methanol production from syngas mixtures and Ni-Ga nanoparticles supported on highly porous silica have been prepared using an incipient wetness impregnation technique from a solution of nickel and gallium nitrates [2]. Tests conducted in a fixed-bed reactor showed...... as catalyst for methanol production. Synthesis, followed by deactivation and a series of regeneration steps at increasing temperature in pure H2 has been carried out in a fixed-bed reactor connected to a gas chromatography system. In each regeneration step, CH4 is generated and the activity of the catalyst...

  13. Influence on the physical properties of methanol-hexane near the critical temperature of bundles

    OpenAIRE

    Породько, Лілія Володимирівна

    2012-01-01

    We are to consider the dynamics of critical phenomena in liquids and the effect of addition of ions on the phase transitions. The influence of the presence of ions on the behavior of inhomogeneous equilibrium solution methanol-hexane near the critical temperature stratification. Experimentally investigated the optical and thermodynamic equilibrium own pure methanol solutions-hexane and methanol-hexane, whether near the critical temperature stratification. Found equation coexistence dual...

  14. ZnCr2S4: Highly effective photocatalyst converting nitrate into N2 without over-reduction under both UV and pure visible light.

    Science.gov (United States)

    Yue, Mufei; Wang, Rong; Cheng, Nana; Cong, Rihong; Gao, Wenliang; Yang, Tao

    2016-08-03

    We propose several superiorities of applying some particular metal sulfides to the photocatalytic nitrate reduction in aqueous solution, including the high density of photogenerated excitons, high N2 selectivity (without over-reduction to ammonia). Indeed, ZnCr2S4 behaved as a highly efficient photocatalyst, and with the assistance of 1 wt% cocatalysts (RuOx, Ag, Au, Pd, or Pt), the efficiency was greatly improved. The simultaneous loading of Pt and Pd led to a synergistic effect. It offered the highest nitrate conversion rate of ~45 mg N/h together with the N2 selectivity of ~89%. Such a high activity remained steady after 5 cycles. The optimal apparent quantum yield at 380 nm was 15.46%. More importantly, with the assistance of the surface plasma resonance effect of Au, the visible light activity achieved 1.352 mg N/h under full arc Xe-lamp, and 0.452 mg N/h under pure visible light (λ > 400 nm). Comparing to the previous achievements in photocatalytic nitrate removal, our work on ZnCr2S4 eliminates the over-reduction problem, and possesses an extremely high and steady activity under UV-light, as well as a decent conversion rate under pure visible light.

  15. ZnCr2S4: Highly effective photocatalyst converting nitrate into N2 without over-reduction under both UV and pure visible light

    Science.gov (United States)

    Yue, Mufei; Wang, Rong; Cheng, Nana; Cong, Rihong; Gao, Wenliang; Yang, Tao

    2016-08-01

    We propose several superiorities of applying some particular metal sulfides to the photocatalytic nitrate reduction in aqueous solution, including the high density of photogenerated excitons, high N2 selectivity (without over-reduction to ammonia). Indeed, ZnCr2S4 behaved as a highly efficient photocatalyst, and with the assistance of 1 wt% cocatalysts (RuOx, Ag, Au, Pd, or Pt), the efficiency was greatly improved. The simultaneous loading of Pt and Pd led to a synergistic effect. It offered the highest nitrate conversion rate of ~45 mg N/h together with the N2 selectivity of ~89%. Such a high activity remained steady after 5 cycles. The optimal apparent quantum yield at 380 nm was 15.46%. More importantly, with the assistance of the surface plasma resonance effect of Au, the visible light activity achieved 1.352 mg N/h under full arc Xe-lamp, and 0.452 mg N/h under pure visible light (λ > 400 nm). Comparing to the previous achievements in photocatalytic nitrate removal, our work on ZnCr2S4 eliminates the over-reduction problem, and possesses an extremely high and steady activity under UV-light, as well as a decent conversion rate under pure visible light.

  16. Clustering dynamics in water/methanol mixtures: a nuclear magnetic resonance study at 205 k

    Science.gov (United States)

    Corsaro, Carmelo; Spooren, Jeroen; Branca, Caterina; Leone, Nancy; Broccio, Matteo; Kim, Chansoo; Chen, Sow-Hsin; Stanley, H Eugene; Mallamace, Francesco

    2008-08-28

    Proton nuclear magnetic resonance (1H NMR) experiments have been performed to measure the spin-lattice, T1, and spin-spin, T2, relaxation times of the three functional groups in water/methanol mixtures at different methanol molar fractions (XMeOH=0, 0.04, 0.1, 0.24, 0.5, 1) as a function of temperature in the range 205 Kmethanol molar fractions, are faster than those of pure water and methanol because of strong interactions, resulting in a complex hydrogen bonding dynamics that determines their thermodynamic properties. In particular, we observe how the interplay between hydrophobicity and hydrophilicity changes with temperature and influences the peculiar thermal behavior of the NMR relaxation times of the solution. The obtained results are interpreted in terms of the existence of stable water-methanol clusters at high temperature whereas, upon cooling to low temperature, clusters of single species are present in the mixture.

  17. Pure- and Mixed-Gas Permeation Properties of Highly Selective and Plasticization Resistant Hydroxyl-Diamine-Based 6FDA Polyimides for CO2/CH4 Separation

    KAUST Repository

    Alaslai, Nasser Y.

    2016-01-05

    The effect of hydroxyl functionalization on the m-phenylene diamine moiety of 6FDA dianhydride-based polyimides was investigated for gas separation applications. Pure-gas permeability coefficients of He, H2, N2, O2, CH4, and CO2 were measured at 35 °C and 2 atm. The introduction of hydroxyl groups in the diamine moiety of 6FDA-diaminophenol (DAP) and 6FDA-diamino resorcinol (DAR) polyimides tightened the overall polymer structure due to increased charge transfer complex formation compared to unfunctionalized 6FDA-m-phenylene diamine (mPDA). The BET surface areas based on nitrogen adsorption of 6FDA-DAP (54 m2g−1) and of 6FDA-DAR (45 m2g−1) were ~18% and 32% lower than that of 6FDA-mPDA (66 m2g−1). 6FDA-mPDA had a pure-gas CO2 permeability of 14 Barrer and CO2/CH4 selectivity of 70. The hydroxyl-functionalized polyimides 6FDA-DAP and 6FDA-DAR exhibited very high pure-gas CO2/CH4 selectivities of 92 and 94 with moderate CO2 permeability of 11 and 8 Barrer, respectively. It was demonstrated that hydroxyl-containing polyimide membranes maintained very high CO2/CH4 selectivity (~ 75 at CO2 partial pressure of 10 atm) due to CO2 plasticization resistance when tested under high-pressure mixed-gas conditions. Functionalization with hydroxyl groups may thus be a promising strategy towards attaining highly selective polyimides for economical membrane-based natural gas sweetening.

  18. Direct Methanol Fuel Cell, DMFC

    Directory of Open Access Journals (Sweden)

    Amornpitoksuk, P.

    2003-09-01

    Full Text Available Direct Methanol Fuel Cell, DMFC is a kind of fuel cell using methanol as a fuel for electric producing. Methanol is low cost chemical substance and it is less harmful than that of hydrogen fuel. From these reasons it can be commercial product. The electrocatalytic reaction of methanol fuel uses Pt-Ru metals as the most efficient catalyst. In addition, the property of membrane and system designation are also effect to the fuel cell efficient. Because of low power of methanol fuel cell therefore, direct methanol fuel cell is proper to use for the energy source of small electrical devices and vehicles etc.

  19. Class I methanol masers: Masers with EGOs

    CERN Document Server

    Chen, Xi; Shen, Zhi-Qiang

    2009-01-01

    We have compared the results of a number of published class I methanol maser surveys with the catalogue of high-mass outflow candidates identified from the GLIMPSE survey (known as extended green objects or EGOs). We find class I methanol masers associated with approximately two-thirds of EGOs. Although the association between outflows and class I methanol masers has long been postulated on the basis of detailed studies of a small number of sources, this result demonstrates the relationship for the first time on a statistical basis. Despite the publication of a number of searches for class I methanol masers, a close physical association with another astrophysical object which could be targeted for the search is still lacking. The close association between class I methanol masers and EGOs therefore provides a large catalogue of candidate sources, most of which have not previously been searched for class I methanol masers. Interstellar masers and outflows have both been proposed to trace an evolutionary sequenc...

  20. 37 GHz methanol masers : Horsemen of the Apocalypse for the class II methanol maser phase?

    CERN Document Server

    Ellingsen, S P; Sobolev, A M; Voronkov, M A; Caswell, J L; Lo, N

    2011-01-01

    We report the results of a search for class II methanol masers at 37.7, 38.3 and 38.5 GHz towards a sample of 70 high-mass star formation regions. We primarily searched towards regions known to show emission either from the 107 GHz class II methanol maser transition, or from the 6.035 GHz excited OH transition. We detected maser emission from 13 sources in the 37.7 GHz transition, eight of these being new detections. We detected maser emission from three sources in the 38 GHz transitions, one of which is a new detection. We find that 37.7 GHz methanol masers are only associated with the most luminous 6.7 and 12.2 GHz methanol maser sources, which in turn are hypothesised to be the oldest class II methanol sources. We suggest that the 37.7 GHz methanol masers are associated with a brief evolutionary phase (of 1000-4000 years) prior to the cessation of class II methanol maser activity in the associated high-mass star formation region.

  1. Hypotensive activity, toxicology and histopathology of opuntioside-I and methanolic extract of Opuntia dillenii.

    Science.gov (United States)

    Saleem, Rubeena; Ahmad, Mohammad; Azmat, Aisha; Ahmad, Syed Iqbal; Faizi, Zareen; Abidi, Lubna; Faizi, Shaheen

    2005-10-01

    Methanolic extract of Opuntia dillenii cladodes and its pure compound alpha-pyrone glycoside, opuntioside-I showed potent hypotensive activity in normotensive rats. Both the extract and opuntioside-I showed comparable effect of 44-54% fall in Mean Arterial Blood Pressure (MABP) at the dose of 10 mg/kg. No mortality was observed in rats even at the doses of 1000 mg/kg/d and 900 mg/kg/d per oral of extract and opuntioside-I respectively. However, histopathology revealed adverse effects of high doses on liver and spleen of the experimental animals.

  2. Information draft on the development of air standards for methanol

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-01-01

    Methanol is a clear, colourless. very mobile liquid with a slightly alcoholic odour in pure form, but a repulsive pungent odour in crude form. Methanol is the raw material in the production of many gasoline additives, is used as a solvent or antifreeze in paint strippers, aerosol spray paints, wall paints, carburetor cleaners, and car windshield washer compounds. Methanol is one of the top pollutants by release quantities in Ontario, the highest release being generated by the pulp and paper industry. Other large emissions come from the plastics and synthetic resin industry. Total release to the air in Canada was 3,668 tonnes in 1996 and the top ten methanol emitting facilities were in Ontario. Methanol is readily absorbed through inhalation, ingestion and skin exposures. Once absorbed, it is oxidized to formaldehyde and then to formic acid. Common symptoms of exposure are visual disturbances, dizziness, nausea, vertigo, pain in the extremities, and headaches. No information was found as to the carcinogenicity of methanol to humans or animals. Current Ontario half-hour POI standard for methanol is 84,000 microgram/cubic meter and the 24-hour AAQC is 28,000 microgram/cubic meter. Both values were established more than 20 years ago. Review of relevant literature, summarized in this report, indicates that five US states have promulgated air quality guidelines or reference exposure levels for methanol, based on occupational exposure limits. The US Environmental Protection Agency is currently reviewing its reference concentration value for methanol. The World Health Organization and the Canadian federal government have not set air quality guidelines for methanol. 37 refs., 1 tab., appendix.

  3. Electrochemical oxidation of methanol on Pt3Co bulk alloy

    Directory of Open Access Journals (Sweden)

    S. LJ. GOJKOVIC

    2003-11-01

    Full Text Available The electrochemical oxidation of methanol was investigated on a Pt3Co bulk alloy in acid solutions. Kinetic parameters such as transfer coefficient, reaction orders with respect to methanol and H+ ions and energy of activation were determined. It was found that the rate of methanol oxidation is significantly diminished by rotation of the electrode. This effect was attributed to the diffusion of formaldehyde and formic acid from the electrode surface. Stirring of the electrolyte also influenced the kinetic parameters of the reaction. It was speculated that the predominant reaction pathway and rate determining step are different in the quiescent and in the stirred electrolyte. Cobalt did not show a promoting effect on the rate of methanol oxidation on the Pt3Co bulk alloy with respect to a pure Pt surface.

  4. Sterion membranes in Direct Methanol fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Linares, J. J.; Lobato, J.; Canizares, P.; Rodrigo, M. A.; Fernandez, A.

    2005-07-01

    Direct Methanol Fuel Cells (DMFCs) has been postulated as an alternative to traditional hydrogen fed Polymer Electrolyte Membrane Fuel Cells (H2-PEMFCs). Among their advantages, it can be pointed out the low cost of the fuel, simplicity of design, large availability, easy handling and distribution. However, there are still some challenges in this field, such as the development of electrocatalysts which can enhance the electrokinetics of methanol oxidation, the discovery of an electrolyte membrane with high conductivity and low methanol crossover at the same time and the production of methanol-tolerant electrocatalysts with high activity for oxygen reduction. So far, Nafion 117 has been the polymer membrane most widely used in DMFCs. Yet, it is well known that Nafion (Du Pont Inc.) membranes are not good barrier for methanol, so that the coulombic efficiency of Nafion-based DMFCs is significantly reduced by the chemical oxidation of methanol in the cathode. Recently, a new perfluorinated polymer with sulphonic acid groups (PFSA) has been developed, under the commercial name of Sterion (David Fuel Cell Components). As a difference as opposed to Nafion, this membrane is cast by the solution casting method, which provides a different sulphonic cluster configuration as compared to the extrusion cast Nafion membranes, which may give rise to different methanol crossover behaviour. In this work, it has been studied and analysed the suitability of Sterion in the DMFCs field. For that, it has been measured the methanol permeability of this membrane at different solute concentration and temperature, and its performance in an actual fuel cell at different operational conditions, such as methanol concentration, temperature and back pressure. Tests have been made using both oxygen and air in the cathode and half-cell potentials have been evaluated in some measurements in order to discriminate the contribution of both semi-reactions to the overall cell overvoltage. A lifetime

  5. Pure laparoscopic augmentation ileocystoplasty.

    Science.gov (United States)

    Rebouças, Rafael B; Monteiro, Rodrigo C; Souza, Thiago N S de; Aragão, Augusto J de; Burity, Camila R T; Nóbrega, Júlio C de A; Oliveira, Natália S C de; Abrantes, Ramon B; Dantas Júnior, Luiz B; Cartaxo Filho, Ricardo; Negromonte, Gustavo R P; Sampaio, Rafael da C R; Britto, Cesar A

    2014-01-01

    Guillain-Barre syndrome is an acute neuropathy that rarely compromises bladder function. Conservative management including clean intermittent catheterization and pharmacotherapy is the primary approach for hypocompliant contracted bladder. Surgical treatment may be used in refractory cases to improve bladder compliance and capacity in order to protect the upper urinary tract. We describe a case of pure laparoscopic augmentation ileocystoplasty in a patient affected by Guillain-Barre syndrome. A 15-year-old female, complaining of voiding dysfunction, recurrent urinary tract infection and worsening renal function for three months. A previous history of Guillain-Barre syndrome on childhood was related. A voiding cystourethrography showed a pine-cone bladder with moderate post-void residual urine. The urodynamic demonstrated a hypocompliant bladder and small bladder capacity (190 mL) with high detrusor pressure (54 cmH2O). Nonsurgical treatments were attempted, however unsuccessfully.

  6. Sixth form pure mathematics

    CERN Document Server

    Plumpton, C

    1968-01-01

    Sixth Form Pure Mathematics, Volume 1, Second Edition, is the first of a series of volumes on Pure Mathematics and Theoretical Mechanics for Sixth Form students whose aim is entrance into British and Commonwealth Universities or Technical Colleges. A knowledge of Pure Mathematics up to G.C.E. O-level is assumed and the subject is developed by a concentric treatment in which each new topic is used to illustrate ideas already treated. The major topics of Algebra, Calculus, Coordinate Geometry, and Trigonometry are developed together. This volume covers most of the Pure Mathematics required for t

  7. Mechanistical Studies on the Irradiation of Methanol in Extraterrestrial Ices

    Science.gov (United States)

    Bennett, Chris J.; Chen, Shih-Hua; Sun, Bing-Jian; Chang, Agnes H. H.; Kaiser, Ralf I.

    2007-05-01

    Pure ices of amorphous methanol, CH3OH(X1A'), were irradiated at 11 K by 5 keV electrons at 100 nA for 1 hr. These energetic electrons simulate electronic energy transfer processes that occur as interstellar ices, comets, and icy solar system bodies are subjected to irradiation from MeV ions and secondary electrons produced in this process. The results were analyzed quantitatively via absorption-reflection-absorption Fourier transform infrared (FTIR) spectroscopy, with the identification of new species aided by high-level electronic structure calculations. The unimolecular decomposition of methanol was found to proceed via the formation of (1) the hydroxymethyl radical, CH2OH(X2A''), and atomic hydrogen, H(2S1/2), (2) the methoxy radical, CH3O(X2A'), plus atomic hydrogen, (3) formaldehyde, H2CO(X1A1) plus molecular hydrogen, H2(X1Σ+g), and (4) the formation of methane, CH4(X1A1), together with atomic oxygen, O(1D). The accessibility of the last channel indicates that the reverse process, oxygen addition into methane to form methanol, should also be feasible. A kinetic model is presented for the decomposition of methanol into these species, as well as the formyl radical, HCO(X2A'), and carbon monoxide, CO(X1Σ+). During the subsequent warming up of the sample, radicals previously generated within the matrix were mobilized and found to recombine to form methyl formate, CH3OCHO(X1A'), glycolaldehyde, CH2OHCHO(X1A'), and ethylene glycol, HOCH 2CH2OH(X1A). Upper limits for the production of these species by the recombination of neighboring radicals produced during irradiation as well as during the warm-up procedure are presented. The generation of these molecules by irradiation of ices in the solid state and their subsequent sublimation into the gas phase can help explain their high abundances as observed toward hot molecular cores and underlines their importance in astrobiology.

  8. Magnetic anisotropy of pure and doped YbInCu sub 4 compounds at ambient and high pressures

    CERN Document Server

    Mushnikov, N V; Rozenfeld, E V; Yoshimura, K; Zhang, W; Yamada, M; Kageyama, H

    2003-01-01

    The susceptibility and high-field magnetization of single-crystalline Yb sub 1 sub - sub x Y sub x InCu sub 4 (x = 0, 0.2 and 0.3) samples have been measured for different field orientations at ambient and high pressures. The compounds with x = 0 and 0.2 undergo a first-order valence transition from the intermediate-valence state to the trivalent state on increasing either temperature or magnetic field. The magnetization and susceptibility of these compounds have appreciable anisotropy in both states. The magnetic phase diagram of Yb sub 1 sub - sub x Y sub x InCu sub 4 determined at ambient pressure is also anisotropic, which is explained by the crystal-field calculations for the free Yb ion in the high-temperature phase. Moreover, the low-temperature magnetization process for x = 0.2 and 0.3 has been measured in low fields under high pressure; it shows anisotropic ferromagnetic ordering.

  9. Preparation of highly pure daidzin on oligo-β-cyclodextrin-Sepharose HP and investigation of chromatographic behavior of isoflavones by molecular docking.

    Science.gov (United States)

    Yang, Li; Li, Cong; Yuan, Tianhu; Tan, Tianwei; Zhang, Liqun

    2011-06-15

    A novel method using column chromatography on oligo-β-cyclodextrin-Sepharose HP for the preparation of high purity daidzin from crude soybean samples was proposed in this work. The isoflavone of daidzin in sample A and B was purified under the optimum mobile phase composed of methanol/acetic acid/water=20.0/8.0/72.0 (v/v/v) at a flow-rate of 1.0 mL/min in one-step operation with a purity of 97.2% and 98.1%, a recovery of 95.3% and 96.3% respectively. The target products in isolated fraction were detected and characterized by HPLC analysis and ESI-MS spectrum. Preparative separation with sample-load of up to 2.42 mg/mL medium gave satisfactory results for daidzin with the purities over 97% and recoveries approximately 90%. Molecular docking simulations were utilized to help demonstrate the inclusion complexation between β-cyclodextrin and the isoflavones in samples through inclusion geometries and calculations of the binding energies. The prediction of the elution orders with AUTODOCK and SURFLEX-DOCK were validated by the chromatographic results.

  10. Self-supported phase-pure Ni3S2 sheet-on-rod nanoarrays with enhanced pseudocapacitive properties and high energy density

    Science.gov (United States)

    Chen, Jun Song; Gui, Yang; Blackwood, Daniel John

    2016-09-01

    In this work, self-supported Ni3S2 nanorod arrays on nickel foam substrate are prepared by a facile one-pot hydrothermal method. These phase-pure nanorods possess an interesting secondary structure: the surface is covered with ultrathin Ni3S2 nanosheets. Such an integration of one-dimensional nanorod array with two-dimensional nanosheets combines the advantages of the two components, demonstrating enhanced pseudocapactive performance with a high and very stable areal capacitance over prolonged charge-discharge tests. When the as-prepared material is incorporated as the cathode in an asymmetric supercapacitor, where activated carbon is selected as the anode, the device exhibits highly reversible capacitance with insignificant decay over 3000 cycles. Excellent energy densities of 115 and 102 Wh kg-1 are achieved at power densities of 506 and 1094 W kg-1, respectively. Such a performance can be attributed to the unique sheet-on-rod nanoarray on the nickel foam substrate.

  11. A high-order, purely frequency based harmonic balance formulation for continuation of periodic solutions: The case of non-polynomial nonlinearities

    CERN Document Server

    Karkar, Sami; Vergez, Christophe; 10.1016/j.jsv.2012.09.033

    2012-01-01

    In this paper, we extend the method proposed by Cochelin and Vergez [A high order purely frequency-based harmonic balance formulation for continuation of periodic solutions, Journal of Sound and Vibration, 324 (2009) 243-262] to the case of non-polynomial nonlinearities. This extension allows for the computation of branches of periodic solutions of a broader class of nonlinear dynamical systems. The principle remains to transform the original ODE system into an extended polynomial quadratic system for an easy application of the harmonic balance method (HBM). The transformation of non-polynomial terms is based on the differentiation of state variables with respect to the time variable, shifting the nonlinear non-polynomial nonlinearity to a time-independent initial condition equation, not concerned with the HBM. The continuation of the resulting algebraic system is here performed by the asymptotic numerical method (high order Taylor series representation of the solution branch) using a further differentiation ...

  12. Chiral counteranion synergistic organocatalysis under high temperature: efficient construction of optically pure spiro[cyclohexanone-oxindole] backbone.

    Science.gov (United States)

    Lan, Yu-Bao; Zhao, Hua; Liu, Zhao-Min; Liu, Guo-Gui; Tao, Jing-Chao; Wang, Xing-Wang

    2011-09-16

    The combination of a cinchona-based chiral primary amine and a BINOL-phosphoric acid has been demonstrated as a powerful and synergistic catalyst system for the double Michael addition of isatylidene malononitriles with α,β-unsaturated ketones, to provide the novel chiral spiro [cyclohexane-1,3'-indoline]-2',3-diones in high yields (88-99%) with excellent diastereo- and enantioselectivities (94:6-99:1 dr's, 95-99% ee's).

  13. Solvation of graphite oxide in water-methanol binary polar solvents

    Energy Technology Data Exchange (ETDEWEB)

    You, Shujie; Yu, Junchun; Sundqvist, Bertil; Talyzin, Alexandr V. [Department of Physics, Umeaa University, SE-901 87 Umeaa (Sweden)

    2012-12-15

    The phase transition between two solvated phases was studied by DSC for graphite oxide (GO) powders immersed in water-methanol mixtures of various compositions. GO forms solid solvates with two different compositions when immersed in methanol. Reversible phase transition between two solvate states due to insertion/desertion of methanol monolayer occurs upon temperature variations. The temperature point and the enthalpy ({Delta}H) of the phase transition are maximal for pure methanol and decrease linearly with increase of water fraction up to 30%. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Highly luminescent pure-red-emitting fluorinated β-diketonate europium(III) complex for full solution-processed OLEDs

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Joao P. [CEMDRX, Physics Department, Universidade de Coimbra, Rua Larga, Coimbra P-3004-516 (Portugal); Serviço de Medicina Nuclear, SESARAM E.P.E., Avenida Luís de Camões 57, Funchal 9004-514, Madeira (Portugal); Martín-Ramos, Pablo [CEMDRX, Physics Department, Universidade de Coimbra, Rua Larga, Coimbra P-3004-516 (Portugal); Higher Technical School of Telecommunications Engineering, Universidad de Valladolid, Campus Miguel Delibes, Paseo Belén 15, Valladolid 47011 (Spain); Coya, Carmen, E-mail: carmen.coya@urjc.es [Escuela Superior de Ciencias Experimentales y Tecnología (ESCET), Universidad Rey Juan Carlos, Madrid 28933 (Spain); Silva, Manuela Ramos [CEMDRX, Physics Department, Universidade de Coimbra, Rua Larga, Coimbra P-3004-516 (Portugal); Eusebio, M. Ermelinda S. [Chemistry Department, Faculdade de Ciências e Tecnologia, Universidade de Coimbra, Coimbra P-3004-535 (Portugal); Andrés, Alicia de [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas (CSIC), Cantoblanco, Madrid 28049 (Spain); Álvarez, Ángel L. [Escuela Superior de Ciencias Experimentales y Tecnología (ESCET), Universidad Rey Juan Carlos, Madrid 28933 (Spain); Martín-Gil, Jesús [Advanced Materials Laboratory, ETSIIAA, Universidad de Valladolid, Avenida de Madrid 44, Palencia 34004 (Spain)

    2015-03-15

    Current manufacturing technologies for OLEDs involve the use of expensive high vacuum techniques and call for thermal stability requirements which are not fulfilled by many materials. These problems disappear when the OLED films are deposited directly from solution. In this study, we have designed, synthesized and characterized a novel octacoordinated complex, Tris(1-(4-chlorophenyl)-4,4,4-trifluoro-1, 3-butanedionate)mono(bathophenanthroline) europium(III), to be used as a “complex-only” emissive layer in wet-processed OLEDs. Upon excitation in the UV region, very efficient energy transfer from the ligands to Eu{sup 3+} takes place, giving rise to intense red emission with very high monochromaticity (R=19), both in powder and as a thin film. The decay times of 754 µs (powder) and 620 µs (thin film) are comparable to those of the most efficient Eu{sup 3+} β-diketonate complexes reported to date. The same energy transfer leading to saturated red and narrow emission is also observed in the OLED device (glass/ITO/PEDOT:PSS/[Eu(cbtfa){sub 3}(bath)]/Ca/Al) when biased at >5.2 V. Its high quantum efficiency (∼60%), good thermal stability up to 200 °C and adequate thin film forming properties make this material a promising chromophore for cost-effective OLEDs. - Highlights: • A highly fluorinated europium(III) octacoordinated complex, [Eu(cbtfa)3(bath)], has been synthesized and its structure elucidated by single crystal X-ray diffraction. • The chosen coordination environment is well-suited for sensitizing the luminescence of the Eu{sup 3+} ion, achieving very efficient energy transfer from the organic ligands (excited in the UV region) to the rare earth ion, leading to highly efficient (Q∼60% in crystalline powder and Q∼50% in thin film) and saturated red photoluminescence. • The material has also been integrated into a single active layer, full solution-processed OLED, with ITO/PEDOT:PSS/[Eu(cbtfa)3(bath)]/ Ca/Al structure.

  15. The toxicity of methanol

    Energy Technology Data Exchange (ETDEWEB)

    Tephly, T.R. (Univ. of Iowa, Iowa City (USA))

    1991-01-01

    Methanol toxicity in humans and monkeys is characterized by a latent period of many hours followed by a metabolic acidosis and ocular toxicity. This is not observed in most lower animals. The metabolic acidosis and blindness is apparently due to formic acid accumulation in humans and monkeys, a feature not seen in lower animals. The accumulation of formate is due to a deficiency in formate metabolism which is, in turn, related, in part, to low hepatic tetrahydrofolate (H{sub 4}folate). An excellent correlation between hepatic H{sub 4} folate and formate oxidation rates has been shown within and across species. Thus, humans and monkeys possess low hepatic H{sub 4}folate levels, low rates of formate oxidation and accumulation of formate after methanol. Formate, itself, produces blindness in monkeys in the absence of metabolic acidosis. In addition to low hepatic H{sub 4}folate concentrations, monkeys and humans also have low hepatic 10-formyl H{sub 4}folate dehydrogenase levels, the enzyme which is the ultimate catalyst for conversion of formate to carbon dioxide. This review presents the basis for the role of folic acid-dependent reactions in the regulation of methanol toxicity.

  16. A green access to highly pure single-walled carbon nanotubes by taurocholate-assistant dispersion and centrifugation

    Science.gov (United States)

    Lian, Yongfu

    2009-09-01

    Raw single-walled carbon nanotubes produced by arc discharge were oxidized in the air to eliminate amorphous carbon, and then dispersed in the aqueous solution of sodium taurocholate supersonically. Thus obtained stable dispersion was subjected to centrifugation, and the metal catalysts and varying carbon impurities were separated with carbon nanotubes. The efficiency of the above procedure was confirmed by scanning electron microscope observation, thermogravimetry, and optical absorption and Raman spectroscopic analyses. The advantage of this procedure lies in easiness, high purity, and no pollution to environment.

  17. Semantic segmentation of forest stands of pure species combining airborne lidar data and very high resolution multispectral imagery

    Science.gov (United States)

    Dechesne, Clément; Mallet, Clément; Le Bris, Arnaud; Gouet-Brunet, Valérie

    2017-04-01

    Forest stands are the basic units for forest inventory and mapping. Stands are defined as large forested areas (e.g., ⩾ 2 ha) of homogeneous tree species composition and age. Their accurate delineation is usually performed by human operators through visual analysis of very high resolution (VHR) infra-red images. This task is tedious, highly time consuming, and should be automated for scalability and efficient updating purposes. In this paper, a method based on the fusion of airborne lidar data and VHR multispectral images is proposed for the automatic delineation of forest stands containing one dominant species (purity superior to 75%). This is the key preliminary task for forest land-cover database update. The multispectral images give information about the tree species whereas 3D lidar point clouds provide geometric information on the trees and allow their individual extraction. Multi-modal features are computed, both at pixel and object levels: the objects are individual trees extracted from lidar data. A supervised classification is then performed at the object level in order to coarsely discriminate the existing tree species in each area of interest. The classification results are further processed to obtain homogeneous areas with smooth borders by employing an energy minimum framework, where additional constraints are joined to form the energy function. The experimental results show that the proposed method provides very satisfactory results both in terms of stand labeling and delineation (overall accuracy ranges between 84 % and 99 %).

  18. Pure colloidal metal and ceramic nanoparticles from high-power picosecond laser ablation in water and acetone.

    Science.gov (United States)

    Bärsch, Niko; Jakobi, Jurij; Weiler, Sascha; Barcikowski, Stephan

    2009-11-04

    The generation of colloids by laser ablation of solids in a liquid offers a nearly unlimited material variety and a high purity as no chemical precursors are required. The use of novel high-power ultra-short-pulsed laser systems significantly increases the production rates even in inflammable organic solvents. By applying an average laser power of 50 W and pulse durations below 10 ps, up to 5 mg min(-1) of nanoparticles have been generated directly in acetone, marking a breakthrough in productivity of ultra-short-pulsed laser ablation in liquids. The produced colloids remain stable for more than six months. In the case of yttria-stabilized zirconia ceramic, the nanoparticles retain the tetragonal crystal structure of the ablated target. Laser beam self-focusing plays an important role, as a beam radius change of 2% on the liquid surface can lead to a decrease of nanoparticle production rates of 90% if the target position is not re-adjusted.

  19. Simulated spatial and temporal dependence of chromium concentration in pure Fe and Fesbnd 14%Cr under high dpa ion irradiation

    Science.gov (United States)

    Vörtler, K.; Mamivand, M.; Barnard, L.; Szlufarska, I.; Garner, F. A.; Morgan, D.

    2016-10-01

    In this work we develop an ab initio informed rate theory model to track the spatial and temporal evolution of implanted ions (Cr+) in Fe and Fesbnd 14%Cr during high dose irradiation. We focus on the influence of the specimen surface, the depth dependence of ion-induced damage, the damage rate, and the consequences of ion implantation, all of which influence the depth dependence of alloy composition evolving with continued irradiation. We investigate chemical segregation effects in the material by considering the diffusion of the irradiation-induced defects. Moreover, we explore how temperature, grain size, grain boundary sink strength, and defect production bias modify the resulting distribution of alloy composition. Our results show that the implanted ion profile can be quite different than the predicted SRIM implantation profile due to radiation enhanced transport and segregation.

  20. Flow of CO2 ethanol and of CO2 methanol in a non-adiabatic microfluidic T-junction at high pressures

    NARCIS (Netherlands)

    Blanch Ojea, R.; Tiggelaar, Roald M.; Pallares, J.; Grau, F.X.; Gardeniers, Johannes G.E.

    2012-01-01

    In this work, an experimental investigation of the single- and multiphase flows of two sets of fluids, CO2–ethanol and CO2–methanol, in a non-adiabatic microfluidic T-junction is presented. The operating conditions ranged from 7 to 18 MPa, and from 294 to 474 K. The feed mass fraction of CO2 in the

  1. Process Design and Economics for the Conversion of Lignocellulosic Biomass to Hydrocarbons via Indirect Liquefaction. Thermochemical Research Pathway to High-Octane Gasoline Blendstock Through Methanol/Dimethyl Ether Intermediates

    Energy Technology Data Exchange (ETDEWEB)

    Tan, E. C. D.; Talmadge, M.; Dutta, A.; Hensley, J.; Schaidle, J.; Biddy, M.; Humbird, D.; Snowden-Swan, L. J.; Ross, J.; Sexton, D.; Yap, R.; Lukas, J.

    2015-03-01

    This report was developed as part of the U.S. Department of Energy’s Bioenergy Technologies Office’s (BETO’s) efforts to enable the development of technologies for the production of infrastructure-compatible, cost-competitive liquid hydrocarbon fuels from lignocellulosic biomass feedstocks. The research funded by BETO is designed to advance the state of technology of biomass feedstock supply and logistics, conversion, and overall system sustainability. It is expected that these research improvements will be made within the 2022 timeframe. As part of their involvement in this research and development effort, the National Renewable Energy Laboratory and the Pacific Northwest National Laboratory investigate the economics of conversion pathways through the development of conceptual biorefinery process models and techno-economic analysis models. This report describes in detail one potential conversion process for the production of high-octane gasoline blendstock via indirect liquefaction of biomass. The processing steps of this pathway include the conversion of biomass to synthesis gas or syngas via indirect gasification, gas cleanup, catalytic conversion of syngas to methanol intermediate, methanol dehydration to dimethyl ether (DME), and catalytic conversion of DME to high-octane, gasoline-range hydrocarbon blendstock product. The conversion process configuration leverages technologies previously advanced by research funded by BETO and demonstrated in 2012 with the production of mixed alcohols from biomass. Biomass-derived syngas cleanup via reforming of tars and other hydrocarbons is one of the key technology advancements realized as part of this prior research and 2012 demonstrations. The process described in this report evaluates a new technology area for the downstream utilization of clean biomass-derived syngas for the production of high-octane hydrocarbon products through methanol and DME intermediates. In this process, methanol undergoes dehydration to

  2. Effect of high hydrostatic pressure processing on norovirus infectivity and genome stability in strawberry puree and mineral water.

    Science.gov (United States)

    Kovač, Katarina; Diez-Valcarce, Marta; Raspor, Peter; Hernández, Marta; Rodríguez-Lázaro, David

    2012-01-03

    We report an evaluation of the effect of various combinations of pressures and times on the inactivation of norovirus (NoV) in two types of matrices that are important in NoV transmission: water and soft fruits. The human NoV surrogate murine norovirus was used as the model virus. The effect of HHP on the viral genome was evaluated by using RT real-time PCR (RT-qPCR), and infectivity assay was used to assess effects on the ability of the virus to attach to and replicate in cells. HHP treatments of 400 MPa for 2.5 min proved to be sufficient for efficient inactivation of NoV (>99.9% reduction). The efficacy of viral inactivation was highly dependent on the matrix in which the virus was present. Therefore, the effect of HHP should be carefully studied in all matrices to which HHP could potentially be applied. Finally, we found no consistent correlation between RT-qPCR and virus infectivity results, and consequently RT-qPCR is not a satisfactory tool for predicting risks to human health.

  3. A VALIDATED REVERSE PHASE HIGH PERFORMANCE LIQUID CHROMATOGRAPHIC METHOD FOR THE DETERMINATION OF DOXOFYLINE IN PURE AND PHARMACEUTICAL FORMULATIONS

    Directory of Open Access Journals (Sweden)

    Lanka Venkateswararao

    2013-02-01

    Full Text Available A novel reverse phase high performance liquid chromatographic method (RP-HPLC was developed and validated for the determination of doxofylline (DXF in pharmaceutical formulations. Agilent 1100 series HPLC instrument equipped with variable wavelength programmable UV-Visible detector and a chromosil C18 (250mm x 4.6mm, 5μm column with an auto injector was used for the present investigation. A volume of 20µL of working standard of concentration 25µg/mL was injected into the chromatographic system, the component was separated by using the mobile phase of the mixture of potassium dihydrogen phosphate buffer of pH 5.5 and acetonitrile in the ratio 75:25(v/v at a flow rate of 1.0 mL/min and the detection of the components was carried out at a wavelength of 275nm. Chemstation software was used for the data acquisition through out the analysis. The system suitable parameters such as number of theoretical plates, tailing factor and resolution were found to be satisfactory. The retention time of the component was found to be at 4.814 minutes. The proposed method was validated in terms of precision, accuracy, linearity, limit of detection, limit of quantification, robustness and ruggedness. The developed method was found to be rapid, simple and sensitive hence it could be used as an alternative method in assay of the doxofylline in any pharmaceutical industries.

  4. A self-supported 40W direct methanol fuel cell system

    Indian Academy of Sciences (India)

    A Manokaran; R Vijayakumar; T N Thomman; P Sridhar; S Pitchumani; A K Shukla

    2011-05-01

    A self-supported 40W Direct Methanol Fuel Cell (DMFC) system has been developed and performance tested. The auxiliaries in the DMFC system comprise a methanol sensor, a liquid-level indicator, and fuel and air pumps that consume a total power of about 5W. The system has a 15-cell DMFC stack with active electrode-area of 45 cm2. The self-supported DMFC system addresses issues related to water recovery from the cathode exhaust, and maintains a constant methanol-feed concentration with thermal management in the system. Pure methanol and water from cathode exhaust are pumped to the methanol-mixing tank where the liquid level is monitored and controlled with the help of a liquid-level indicator. During the operation, methanol concentration in the feed solution at the stack outlet is monitored using a methanol sensor, and pure methanol is added to restore the desired methanol concentration in the feed tank by adding the product water from the cathode exhaust. The feed-rate requirements of fuel and oxidant are designed for the stack capacity of 40W. The self-supported DMFC system is ideally suited for various defense and civil applications and, in particular, for charging the storage batteries.

  5. Simulation and reference interaction site model theory of methanol and carbon tetrachloride mixtures.

    Science.gov (United States)

    Munaò, G; Costa, D; Saija, F; Caccamo, C

    2010-02-28

    We report molecular dynamics and reference interaction site model (RISM) theory of methanol and carbon tetrachloride mixtures. Our study encompasses the whole concentration range, by including the pure component limits. We majorly focus on an analysis of partial, total, and concentration-concentration structure factors, and examine in detail the k-->0 limits of these functions. Simulation results confirm the tendency of methanol to self-associate with the formation of ring structures in the high dilution regime of this species, in agreement with experimental studies and with previous simulations by other authors. This behavior emerges as strongly related to the high nonideality of the mixture, a quantitative estimate of which is provided in terms of concentration fluctuation correlations, through the structure factors examined. The interaggregate correlation distance is also thereby estimated. Finally, the compressibility of the mixture is found in good agreement with experimental data. The RISM predictions are throughout assessed against simulation; the theory describes better the apolar solvent than the alcohol properties. Self-association of methanol is qualitatively reproduced, though this trend is much less marked in comparison with simulation results.

  6. Synthesis of pure colloidal silver nanoparticles with high electroconductivity for printed electronic circuits: the effect of amines on their formation in aqueous media.

    Science.gov (United States)

    Natsuki, Jun; Abe, Takao

    2011-07-01

    This paper describes a practical and convenient method to prepare stable colloidal silver nanoparticles for use in printed electronic circuits. The method uses a dispersant and two kinds of reducing agents including 2-(dimethylamino) ethanol (DMAE), which play important roles in the reduction of silver ions in an aqueous medium. The effect of DMAE and dispersant, as well as the factors affecting particle size and morphology are investigated. In the formation of the silver nanoparticles, reduction occurs rapidly at room temperature and the silver particles can be separated easily from the mixture in a short time. In addition, organic solvents are not used. Pure, small and relatively uniform particles with a diameter less than 10 nm can be obtained that exhibit high electroconductivity. The silver nanoparticles are stable, and can be isolated as a dried powder that can be fully redispersed in deionized water. This method of producing colloidal silver nanoparticles will find practical use in electronics applications.

  7. Influence of strain amount on stabilization of {omega}-phase in pure Ti by severe plastic deformation under high-pressure torsion

    Energy Technology Data Exchange (ETDEWEB)

    Todaka, Y; Azuma, H; Ohnishi, Y; Umemoto, M [Department of Production Systems Engineering, Toyohashi University of Technology, Hibarigaoka 1-1, Tempaku, Toyohashi, Aichi 441-8580 (Japan); Suzuki, H, E-mail: todaka@martens.pse.tut.ac.j [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Shirakata-Shirane 2-4, Tokai, Naka, Ibaraki 319-1195 (Japan)

    2010-07-01

    In pure Ti, the influence of shear deformation on the {alpha} to {omega} transformation and the development of texture in the {omega}-phase under high-pressure torsion (HPT) straining were investigated by means of X-ray and neutron diffractions. The fraction of {omega}-phase increased with strain in the {omega}-phase state. Bulk submicrocrystalline {omega}-Ti was fabricated by HPT-straining under the compressive pressure P = 5 GPa with the equivalent strain {epsilon}{sub eq} > 110 at the rotation speed of 3.3 x 10{sup -3} rev. per sec. (0.2 rev. per min.) at room temperature. The texture of {omega}-phase evolved by HPT-straining with the prismatic planes parallel to the shear direction of HPT-straining and the basal planes perpendicular to it.

  8. Efficient green methanol synthesis from glycerol

    Science.gov (United States)

    Haider, Muhammad H.; Dummer, Nicholas F.; Knight, David W.; Jenkins, Robert L.; Howard, Mark; Moulijn, Jacob; Taylor, Stuart H.; Hutchings, Graham J.

    2015-12-01

    The production of biodiesel from the transesterification of plant-derived triglycerides with methanol has been commercialized extensively. Impure glycerol is obtained as a by-product at roughly one-tenth the mass of the biodiesel. Utilization of this crude glycerol is important in improving the viability of the overall process. Here we show that crude glycerol can be reacted with water over very simple basic or redox oxide catalysts to produce methanol in high yields, together with other useful chemicals, in a one-step low-pressure process. Our discovery opens up the possibility of recycling the crude glycerol produced during biodiesel manufacture. Furthermore, we show that molecules containing at least two hydroxyl groups can be converted into methanol, which demonstrates some aspects of the generality of this new chemistry.

  9. Silicon Based Direct Methanol Fuel Cells

    DEFF Research Database (Denmark)

    Larsen, Jackie Vincent

    The purpose of this project has been to investigate and fabricate small scale Micro Direct Methanol Fuel Cells (μDMFC). They are investigated as a possible alternative for Zinc-air batteries in small size consumer devices such as hearing aids. In such devices the conventional rechargeable batteries...... such as lithium-ion batteries have insufficiently low energy density. Methanol is a promising fuel for such devices due to the high energy density and ease of refueling compared to charging batteries, making μDMFC a suitable replacement energy source. In this Ph.D. dissertation, silicon micro fabrication...

  10. Atmospheric methanol measurement using selective catalytic methanol to formaldehyde conversion

    Directory of Open Access Journals (Sweden)

    S. J. Solomon

    2005-01-01

    Full Text Available A novel atmospheric methanol measurement technique, employing selective gas-phase catalytic conversion of methanol to formaldehyde followed by detection of the formaldehyde product, has been developed and tested. The effects of temperature, gas flow rate, gas composition, reactor-bed length, and reactor-bed composition on the methanol conversion efficiency of a molybdenum-rich, iron-molybdate catalyst [Mo-Fe-O] were studied. Best results were achieved using a 1:4 mixture (w/w of the catalyst in quartz sand. Optimal methanol to formaldehyde conversion (>95% efficiency occurred at a catalyst housing temperature of 345°C and an estimated sample-air/catalyst contact time of <0.2 seconds. Potential interferences arising from conversion of methane and a number of common volatile organic compounds (VOC to formaldehyde were found to be negligible under most atmospheric conditions and catalyst housing temperatures. Using the new technique, atmospheric measurements of methanol were made at the University of Bremen campus from 1 to 15 July 2004. Methanol mixing ratios ranged from 1 to 5 ppb with distinct maxima at night. Formaldehyde mixing ratios, obtained in conjunction with methanol by periodically bypassing the catalytic converter, ranged from 0.2 to 1.6 ppb with maxima during midday. These results suggest that selective, catalytic methanol to formaldehyde conversion, coupled with existing formaldehyde measurement instrumentation, is an inexpensive and effective means for monitoring atmospheric methanol.

  11. Atmospheric methanol measurement using selective catalytic methanol to formaldehyde conversion

    Directory of Open Access Journals (Sweden)

    S. J. Solomon

    2005-05-01

    Full Text Available A novel atmospheric methanol measurement technique, employing selective gas-phase catalytic conversion of methanol to formaldehyde followed by detection of the formaldehyde product, has been developed and tested. The effects of temperature, gas flow rate, gas composition, reactor-bed length, and reactor-bed composition on the methanol conversion efficiency of a molybdenum-rich, iron-molybdate catalyst [Mo-Fe-O] were studied. Best results were achieved using a 1:4 mixture (w/w of the catalyst in quartz sand. Optimal methanol to formaldehyde conversion (>95% efficiency occurred at a catalyst housing temperature of 345°C and an estimated sample-air/catalyst contact time of <0.2 s. Potential interferences arising from conversion of methane and a number of common volatile organic compounds (VOC to formaldehyde were found to be negligible under most atmospheric conditions and catalyst housing temperatures. Using the new technique, atmospheric measurements of methanol were made at the University of Bremen campus from 1 to 15 July 2004. Methanol mixing ratios ranged from 1 to 5 ppb with distinct maxima at night. Formaldehyde mixing ratios, obtained in conjunction with methanol by periodically bypassing the catalytic converter, ranged from 0.2 to 1.6 ppb with maxima during midday. These results suggest that selective, catalytic methanol to formaldehyde conversion, coupled with existing formaldehyde measurement instrumentation, is an inexpensive and effective means for monitoring atmospheric methanol.

  12. Development of new membrane materials for direct methanol fuel cells

    NARCIS (Netherlands)

    Yildirim, Mustafa Hakan

    2009-01-01

    Development of new membrane materials for direct methanol fuel cells Direct methanol fuel cells (DMFCs) can convert the chemical energy of a fuel directly into electrical energy with high efficiency and low emission of pollutants. DMFCs can be used as the power sources to portable electronic devices

  13. Development of new membrane materials for direct methanol fuel cells

    NARCIS (Netherlands)

    Yildirim, M.H.

    2009-01-01

    Development of new membrane materials for direct methanol fuel cells Direct methanol fuel cells (DMFCs) can convert the chemical energy of a fuel directly into electrical energy with high efficiency and low emission of pollutants. DMFCs can be used as the power sources to portable electronic devices

  14. 高压缩比甲醇发动机的性能和排放研究%Performance and Emissions Research of the High Compression Ratio Methanol Engine

    Institute of Scientific and Technical Information of China (English)

    王晋; 朱建军; 王勇; 刘磊; 高聪慧

    2014-01-01

    用一辆农用拖拉机的柴油机进行台架试验。在一台1115单缸柴油机上,经过加装电热塞、增大压缩比和喷油泵直径的改装后燃用M100甲醇燃料,并对改装后的甲醇发动机与原柴油机进行对比试验。试验结果表明:甲醇发动机的动力性比原柴油机高,经济性得到改善;尾气排放中甲醇发动机 NOx平均降低45%,尽管 HC和CO的排放整体比柴油机高,但在大负荷时可以平均降低70%;并且在尾气进行三元催化处理后,可以使 HC和CO排放降低到与柴油机一样。通过试验对比,对甲醇替代柴油的可能提供了理论依据,对柴油机节能减排具有重大意义。%The experiment uses an farm tractor diesel engine to conduct an bench test .To make it burns M100 methanol fuel ,we add a glow plug , enlarge the compression ratio and the diameter of fuel injection pump on a 1115 single cylinder diesel engine , and combine the test research between the methanol engine and the original diesel engine .Results shows that the methanol engine can improve dynamic and economy;The methanol engine can reduce 45%averagely on NO x e-missions;Although HC and CO emissions are higher than the original diesel engine , but the methanol engine also can re-duce by 70%on average in high loads .emissions decreace the same as the original engine's after the tail gas is treated by three-way catalytic converter .According to the research , it provides a theoretical basis that methanol could replace diesel and makes great significance for energy save and emission reduction .

  15. Methanol poisoning. VI. Role of folic acid in the production of methanol poisoning in the rat

    Energy Technology Data Exchange (ETDEWEB)

    Makar, A.B. (Alexandria Univ., Egypt); Tephly, T.R.

    1977-05-01

    Methanol poisoning is well known to occur in humans but does not develop in common laboratory animals such as the rat. Rodents display neither metabolic acidosis nor ocular toxicity after methanol treatment, findings that commonly result in humans and that have recently been described in the monkey. Since methanol administration in the monkey leads to marked accumulation of formic acid and metabolic acidosis, experiments were devised to reduce formate metabolism in the rat and thereby study whether methanol administration would lead to the accumulation of formic acid and acidosis in that species. Several methods were employed to induce a state of folate deficiency in the rat, a prerequisite to producing a decrease in formate oxidation to CO/sub 2/ in that species. Rats placed on a folate-deficient diet for 10-12 wk showed a marked decrease in formate oxidation and a marked sensitivity to methanol poisoning, as evidenced by high blood formate levels and marked decreases in blood pH. Treatment of rats with methotrexate was relatively ineffective in inducing decreases in formate oxidation, but in rats fed a folate-deficient diet for 9 days and injected once daily for 9 days with 1 mg/kg methotrexate, a significant elevation of blood formate and decrease in blood pH was observed. In rats that were acidotic following methanol administration no accumulation of formaldehyde was observed. These results indicate that it is possible to sensitize the rat to methanol poisoning by reducing its capacity to oxidize formate. They also show that once the rat is susceptible to methanol poisoning, metabolic acidosis and formate accumulation occur without the accumulation of formaldehyde.

  16. Simultaneous observation of water and class I methanol masers toward class II methanol maser sources

    CERN Document Server

    Kang, Hyunwoo; Byun, Do-Young; Lee, Seokho; Park, Yong-Sun

    2015-01-01

    We present a simultaneous single-dish survey of 22 GHz water maser and 44 GHz and 95 GHz class I methanol masers toward 77 6.7 GHz class II methanol maser sources, which were selected from the Arecibo methanol maser Galactic plane survey (AMGPS) catalog.Water maser emission is detected in 39 (51%) sources, of which 15 are new detections. Methanol maser emission at 44 GHz and 95 GHz is found in 25 (32%) and 19 (25%) sources, of which 21 and 13 sources are newly detected, respectively. We find 4 high-velocity (> 30 km/s) water maser sources, including 3 dominant blue- or redshifted outflows.The 95 GHz masers always appear with the 44 GHz maser emission. They are strongly correlated with 44 GHz masers in velocity, flux density, and luminosity, while they are not correlated with either water or 6.7 GHz class II methanol masers. The average peak flux density ratio of 95 GHz to 44 GHz masers is close to unity, which is two times higher than previous estimates. The flux densities of class I methanol masers are more ...

  17. Rehabilitation of pure alexia

    DEFF Research Database (Denmark)

    Starrfelt, Randi; Ólafsdóttir, Rannveig Rós; Arendt, Ida-Marie

    2013-01-01

    Acquired reading problems caused by brain injury (alexia) are common, either as a part of an aphasic syndrome, or as an isolated symptom. In pure alexia, reading is impaired while other language functions, including writing, are spared. Being in many ways a simple syndrome, one would think...... that pure alexia was an easy target for rehabilitation efforts. We review the literature on rehabilitation of pure alexia from 1990 to the present, and find that patients differ widely on several dimensions like alexia severity, and associated deficits. Many patients reported to have pure alexia...... in the reviewed studies, have associated deficits like agraphia or aphasia and thus do not strictly conform to the diagnosis. Few studies report clear and generalisable effects of training, none report control data, and in many cases the reported findings are not supported by statistics. We can, however...

  18. Rehabilitation of pure alexia

    DEFF Research Database (Denmark)

    Starrfelt, Randi; Ólafsdóttir, Rannveig Rós; Arendt, Ida-Marie

    2013-01-01

    that pure alexia was an easy target for rehabilitation efforts. We review the literature on rehabilitation of pure alexia from 1990 to the present, and find that patients differ widely on several dimensions like alexia severity, and associated deficits. Many patients reported to have pure alexia......Acquired reading problems caused by brain injury (alexia) are common, either as a part of an aphasic syndrome, or as an isolated symptom. In pure alexia, reading is impaired while other language functions, including writing, are spared. Being in many ways a simple syndrome, one would think...... in the reviewed studies, have associated deficits like agraphia or aphasia and thus do not strictly conform to the diagnosis. Few studies report clear and generalisable effects of training, none report control data, and in many cases the reported findings are not supported by statistics. We can, however...

  19. Evidence of anomalous behavior of intermolecular interactions at low concentration of methanol in ethanol-methanol binary system.

    Science.gov (United States)

    Nilavarasi, K; Kartha, Thejus R; Madhurima, V

    2018-01-05

    At low concentrations of methanol in a binary system of ethanol and methanol, uniquely complex molecular interactions are reported here. Previous studies indicate that ethanol molecules form aggregates held together by hydrogen bonding (O-H-O) and also dispersive forces. Addition of small amount of methanol tends to break the hydrogen bond network of ethanol due to the larger polarity of methanol. This leads to the ethanol molecules becoming somewhat isolated from each other within a scaffolding network of methanol molecules, as seen from the present molecular dynamics simulations. This is an indication of a repulsive force that dominates among the two different alcohols. At higher molar concentration of methanol (Xm > 0.3817), the strength and extent (number) of formation of hydrogen bonds between ethanol and methanol increase. The geometry of molecular structure at high concentration favors the fitting of component molecules with each other. Intermolecular interactions in the ethanol-methanol binary system over the entire concentration range were investigated in detail using broadband dielectric spectroscopy, FTIR, surface tension and refractive index studies. Molecular dynamics simulations show that the hydrogen bond density is a direct function of the number of methanol molecules present, as the ethanol aggregates are not strictly hydrogen-bond constructed which is in agreement with the experimental results. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Medical high-resolution image sharing and electronic whiteboard system: A pure-web-based system for accessing and discussing lossless original images in telemedicine.

    Science.gov (United States)

    Qiao, Liang; Li, Ying; Chen, Xin; Yang, Sheng; Gao, Peng; Liu, Hongjun; Feng, Zhengquan; Nian, Yongjian; Qiu, Mingguo

    2015-09-01

    There are various medical image sharing and electronic whiteboard systems available for diagnosis and discussion purposes. However, most of these systems ask clients to install special software tools or web plug-ins to support whiteboard discussion, special medical image format, and customized decoding algorithm of data transmission of HRIs (high-resolution images). This limits the accessibility of the software running on different devices and operating systems. In this paper, we propose a solution based on pure web pages for medical HRIs lossless sharing and e-whiteboard discussion, and have set up a medical HRI sharing and e-whiteboard system, which has four-layered design: (1) HRIs access layer: we improved an tile-pyramid model named unbalanced ratio pyramid structure (URPS), to rapidly share lossless HRIs and to adapt to the reading habits of users; (2) format conversion layer: we designed a format conversion engine (FCE) on server side to real time convert and cache DICOM tiles which clients requesting with window-level parameters, to make browsers compatible and keep response efficiency to server-client; (3) business logic layer: we built a XML behavior relationship storage structure to store and share users' behavior, to keep real time co-browsing and discussion between clients; (4) web-user-interface layer: AJAX technology and Raphael toolkit were used to combine HTML and JavaScript to build client RIA (rich Internet application), to meet clients' desktop-like interaction on any pure webpage. This system can be used to quickly browse lossless HRIs, and support discussing and co-browsing smoothly on any web browser in a diversified network environment. The proposal methods can provide a way to share HRIs safely, and may be used in the field of regional health, telemedicine and remote education at a low cost.

  1. Methanol - alternative fuel road traffic

    Energy Technology Data Exchange (ETDEWEB)

    Muendler, H.

    1980-09-01

    This brochure names the fuel properties that are required for road traffic, discusses the replacement of petrol by methanol, discusses the possibilities of manufacturing methanol, draws up a timetable and an organigram for a (M-15) large scale test and compares costs of petrol, methanol, synthesis process petrol and hydrogenation process petrol. Furthermore, the technical requirements of vehicles as well as test results of exhaust gas emissions are also discussed.

  2. Pure Laparoscopic Augmentation Ileocystoplasty

    Directory of Open Access Journals (Sweden)

    Rafael B. Rebouças

    2014-12-01

    Full Text Available Introduction Guillain-Barre syndrome is an acute neuropathy that rarely compromises bladder function. Conservative management including clean intermittent catheterization and pharmacotherapy is the primary approach for hypocompliant contracted bladder. Surgical treatment may be used in refractory cases to improve bladder compliance and capacity in order to protect the upper urinary tract. We describe a case of pure laparoscopic augmentation ileocystoplasty in a patient affected by Guillain-Barre syndrome. Presentation A 15-year-old female, complaining of voiding dysfunction, recurrent urinary tract infection and worsening renal function for three months. A previous history of Guillain-Barre syndrome on childhood was related. A voiding cystourethrography showed a pine-cone bladder with moderate post-void residual urine. The urodynamic demonstrated a hypocompliant bladder and small bladder capacity (190mL with high detrusor pressure (54 cmH2O. Nonsurgical treatments were attempted, however unsuccessfully. The patient was placed in the exaggerated Trendelenburg position. A four-port transperitoneal technique was used. A segment of ileum approximately 15-20cm was selected and divided with its pedicle. The ileal anastomosis and creation of ileal U-shaped plate were performed laparoscopically, without staplers. Bladder mobilization and longidutinal cystotomy were performed. Enterovesical anastomosis was done with continuous running suture. A suprapubic cystostomy was placed through a 5mm trocar. Results The total operative time was 335 min. The blood loss was minimal. The patient developed ileus in the early days, diet acceptance after the fourth day and was discharged on the seventh postoperative day. The urethral catheter was removed after 2 weeks. At 6-month follow-up, a cystogram showed a significant improvement in bladder capacity. The patient adhered well to clean intermittent self-catheterization and there was no report for febrile infections

  3. Purification of methanol dehydrogenase from mouth methylotrophic bacteria of tropical region

    Directory of Open Access Journals (Sweden)

    Waturangi, D.

    2011-01-01

    Full Text Available Aims: Purification of methanol dehydrogenase (MDH from methylotrophic bacteria was conducted to obtain pure enzyme for further research and industrial applications due to the enzyme’s unique activity that catalyzes oxidation of methanol as an important carbon source in methylotrophic bacteria.Methodology and Results: The enzyme was screened from methylotrophic bacteria isolated from human mouth. Purification of this enzyme was conducted using ammonium sulphate precipitation followed by cation exchange chromatography. Two types of media were used to produce the enzymes: luria broth and standard mineral salts media (MSM. MSM produced MDH with higher specific activity than LB. Specific activity was also increased along with the purification steps. Application of ammonium sulphate increased the purity of enzyme and was more effective for the enzyme produced in LB. Using sepharose increased the enzyme activity 10 -57 folds.Conclusion, significant and impact of this study: With this, ammonium sulphate precipitation coupled with single cation exchange chromatographic system has been proved to provide sufficient purified of methanol dehydrogenase from methylotrophic bacteria origin of human mouth with high specific activity for further application.

  4. Very high resolution far infrared synchrotron radiation spectrum of methanol-D1 (CH2DOH) in the first three torsional-vibrational modes

    Science.gov (United States)

    Mukhopadhyay, Indra; Billinghurst, B. E.

    2016-11-01

    In our effort to systematically study the far infrared (FIR) spectra of asymmetrically mono deuterated methanol (CH2DOH) and thereby obtain the transition wavenumbers with better and better accuracy (Mukhopadhyay, 2016a,b), the complete Fourier transform (FT) spectra from FIR to infrared (IR) vibrational bands (in the range 50-1190 cm-1) have been re-recorded using the Synchrotron Radiation Source at the Canadian Light Sources in Saskatchewan, Canada. The resolution of the spectrum is unprecedented, reaching beyond the Doppler limited resolution as low as about 0.0008 cm-1 with a signal to noise (S/N) ratio is many fold better than that can be obtained by commercially available FT spectrometer using thermal sources (e.g., Globar). Spectra were also recorded beyond 1190 cm-1 to about 5000 cm-1 at a somewhat lower resolution of 0.002-0.004 cm-1. In this report the analysis of the b-type and c-type torsional - rotational spectra in the ground vibrational state corresponding to gauche- (e1/o1) to gauche- (e1/o1) and gauche- (e1/o1) to trans- (e0) states in the ground vibrational state are reported and an atlas of the wavenumber for about 2500 FIR assigned absorption lines has been prepared. The transitions within a given sub-band are analyzed using state dependent expansion parameters and the Q-branch origins. The data from previous results (Mukhopadhyay, 2016a,b) along with the present work allowed a global analysis yielding a complete set of molecular parameters. The state dependent molecular parameters reproduce the experimental wavenumbers within experimental uncertainty. In addition, the sensitivity of the spectrum allowed observation of forbidden transitions previously unobserved and helped reassignment of rotational angular momentum quantum numbers of some ΔK = ±1, Q-branch transitions in highly excited states recently reported in the literature. To our knowledge the wavenumbers reported in the present work are the most accurate so far reported in the

  5. Characterization and Uncertainty Assessment of a Certified Reference Material of Chloramphenicol in Methanol (GBW(E)082557).

    Science.gov (United States)

    Yang, Mengrui; Wang, Min; Zhou, Jian; Song, Yinqing; Wang, Tongtong

    2016-01-01

    Prior to preparation of CRM candidate of chloramphenicol in methanol with a concentration of 100 mg/L, two independent methods including mass balance (MB) and quantitative nuclear magnetic resonance (qNMR) were employed to precisely measure the mass fraction of pure chloramphenicol materials. The mass fraction was assigned to be 99.8% with uncertainty of 0.3%. Homogeneity testing and stability study of chloramphenicol in methanol were examined by using high performance liquid chromatography. Additionally, the uncertainties originating from the process of CRM development were comprehensively evaluated. The experimental results indicate that the property value of this CRM is homogeneous and stable at 4°C for at least six months. The new CRM (GBW(E)082557) can be applicable to calibration of instrument and assurance of accuracy and comparability of results in routine measurement.

  6. Characterization and Uncertainty Assessment of a Certified Reference Material of Chloramphenicol in Methanol (GBW(E)082557)

    Science.gov (United States)

    Zhou, Jian; Song, Yinqing; Wang, Tongtong

    2016-01-01

    Prior to preparation of CRM candidate of chloramphenicol in methanol with a concentration of 100 mg/L, two independent methods including mass balance (MB) and quantitative nuclear magnetic resonance (qNMR) were employed to precisely measure the mass fraction of pure chloramphenicol materials. The mass fraction was assigned to be 99.8% with uncertainty of 0.3%. Homogeneity testing and stability study of chloramphenicol in methanol were examined by using high performance liquid chromatography. Additionally, the uncertainties originating from the process of CRM development were comprehensively evaluated. The experimental results indicate that the property value of this CRM is homogeneous and stable at 4°C for at least six months. The new CRM (GBW(E)082557) can be applicable to calibration of instrument and assurance of accuracy and comparability of results in routine measurement. PMID:27493666

  7. VLT/ISAAC infrared spectroscopy of embedded high-mass YSOs in the Large Magellanic Cloud: Methanol and the 3.47 μm band

    Science.gov (United States)

    Shimonishi, T.; Dartois, E.; Onaka, T.; Boulanger, F.

    2016-01-01

    only marginally lower than those of the Galactic sources. Conclusions: We propose that grain surface reactions at a relatively high dust temperature (warm ice chemistry) are responsible for the observed characteristics of ice chemical compositions in the LMC; i.e., the low abundance of solid CH3OH presented in this work as well as the high abundance of solid CO2 reported in previous studies. We suggest that this warm ice chemistry is one of the important characteristics of interstellar and circumstellar chemistry in low metallicity environments. The low abundance of CH3OH in the solid phase implies that formation of complex organic molecules from methanol-derived species is less efficient in the LMC. For the 3.47 μm band, the observed difference in the water ice threshold may suggest that a more shielded environment is necessary for the formation of the 3.47 μm band carrier in the LMC. On the one hand, in well-shielded regions of the LMC, our results suggest that the lower metallicity and different interstellar environment of the LMC have little effect on the abundance ratio of the 3.47 μm band carrier and water ice. Based on observations with the Very Large Telescope at the European Southern Observatory, Paranal, Chile (ESO programme ID 090.C-0497).

  8. Solvatochromism and preferential solvation in mixtures of Methanol with Ethanol, 1-Propanol and 1-Butanol

    Directory of Open Access Journals (Sweden)

    Masoumeh Sayadian

    2014-12-01

    Full Text Available The spectral shift of 4-nitroaniline was determined in pure methanol, ethanol, 1-propanol and 1-butanol and binary mixtures of methanol with other 1-alkanols at 25 ⁰C by UV-vis spectroscopy. The effect of specific and non-specific solute-solvent interactions on the spectral shift was investigated by using the linear solvation energy relationship concept. A multiple linear regression analysis was used to correlate the spectral shift with microscopic Kamlet-Taft parameters (a, b and p* in pure solvents. Results indicate that the spectral shift is highly related with the specific solute-solvent interactions. In binary mixtures, a nonideal behavior of spectral shift was observed respective to the analytical mole fraction of alcohols; indicating preferential solvation. The spectral shifts were fitted to a known preferential solvation model named solvent exchange model to calculate the preferential solvation parameters. The preference of solute to be solvated by one of the solvating species relative to others was explained in terms of solvent-solvent and solute-solvent interactions.

  9. Defining minimum essential factors to derive highly pure human endothelial cells from iPS/ES cells in an animal substance-free system.

    Science.gov (United States)

    Wu, Yu-Ting; I-Shing Yu; Tsai, Kuen-Jer; Shih, Chien-Yu; Hwang, Shiaw-Min; Su, Ih-Jen; Chiang, Po-Min

    2015-04-13

    It is desirable to obtain unlimited supplies of endothelial cells for research and therapeutics. However, current methods of deriving endothelial cells from humans suffer from issues, such as limited supplies, contamination from animal substances, and lengthy/complicated procedures. In this article we developed a way to differentiate human iPS and ES cells to highly pure endothelial cells in 5 days. The chemically defined system is robust, easy to perform, and free of animal substances. Using the system, we verified that combined TGFβ and canonical Wnt agonists are essential and sufficient for iPS/ES cell-to-mesoderm transition. Besides, VEGF-KDR signaling alone is required for endothelial formation at high density while supplementation with FGF allows for colonial endothelial differentiation. Finally, anti-adsorptive agents could enrich the endothelial output by allowing selective attachment of the endothelial precursors. The system was validated to work on multiple iPS/ES cells lines to produce endothelial cells capable of forming capillary-like structures in vitro and integrating into host vasculature in vivo. In sum, the simple yet robust differentiation system permits the unlimited supply of human endothelial cells. The defined and animal substance-free nature of the system is compatible with clinical applications and characterization of endothelial differentiation in an unbiased manner.

  10. Methylnaltrexone bromide methanol monosolvate

    Directory of Open Access Journals (Sweden)

    Xinbo Zhou

    2012-03-01

    Full Text Available In the title compound [systematic name: (4R,4aS,7aR,12bS-3-cyclopropylmethyl-4a,9-hydroxy-7-oxo-2,3,4,4a,5,6,7,7a-octahydro-1H-4,12-methanobenzofuro[3,2-e]isoquinolin-3-ium bromide methanol monosolvate], C21H26NO4+·Br−·CH3OH, two of the three six-membered rings adopt chair conformations while the third, which contains a C=C double bond, adopts an approximate half-boat conformation. The 2,3-dihydrofuran ring adopts an envelope conformation. In the crystal, the components are linked by O—H...O and O—H...Br hydrogen bonds. The absolute stereochemistry was inferred from one of the starting materials.

  11. Methanol synthesis beyond chemical equilibrium

    NARCIS (Netherlands)

    van Bennekom, J. G.; Venderbosch, R. H.; Winkelman, J. G. M.; Wilbers, E.; Assink, D.; Lemmens, K. P. J.; Heeres, H. J.

    2013-01-01

    In commercial methanol production from syngas, the conversion is thermodynamically limited to 0.3-0.7 leading to large recycles of non-converted syngas. This problem can be overcome to a significant extent by in situ condensation of methanol during its synthesis which is possible nowadays due to the

  12. Macroscopic Modeling of Transport Phenomena in Direct Methanol Fuel Cells

    DEFF Research Database (Denmark)

    Olesen, Anders Christian

    An increasing need for energy efficiency and high energy density has sparked a growing interest in direct methanol fuel cells for portable power applications. This type of fuel cell directly generates electricity from a fuel mixture consisting of methanol and water. Although this technology...... for studying their transport. In this PhD dissertation the macroscopic transport phenomena governing direct methanol fuel cell operation are analyzed, discussed and modeled using the two-fluid approach in the computational fluid dynamics framework of CFX 14. The overall objective of this work is to extend...... the present fundamental understanding of direct methanol fuel cell operation by developing a three-dimensional, two-phase, multi-component, non-isotherm mathematical model including detailed non-ideal thermodynamics, non-equilibrium phase change and non-equilibrium sorption-desorption of methanol and water...

  13. Toxic cocktail: methanol poisoning in a tourist to Indonesia.

    Science.gov (United States)

    Gee, Paul; Martin, Elizabeth

    2012-08-01

    Methanol poisoning has become very uncommon in Australasia with regulations that have reduced its retail availability. This report describes a young tourist who developed sudden onset visual failure and rapid breathing 2 days after ingestion of a complimentary local drink called Arrack when travelling in Indonesia. She presented to a hospital in New Zealand with severe metabolic acidosis and a highly toxic methanol level at 17 mmol/L. The cocktail was consumed at a popular tourist bar but is likely to have been mixed from home-brewed or 'moonshine' alcohol tainted with methanol. The aetiology of methanol poisoning, its optic toxicology and therapeutic measures are discussed, as is the concerning number of methanol poisoning cases among tourists to Indonesia over recent years.

  14. Necrosis and haemorrhage of the putamen in methanol poisoning shown on MRI

    Energy Technology Data Exchange (ETDEWEB)

    Kuteifan, K.; Gutbub, A.M.; Laplatte, G. [Service de Reanimation Medicale, Centre Hospitalier Louis Pasteur, Colmar (France); Oesterle, H.; Tajahmady, T. [Service de Neuroradiologie, Centre Hospitalier Louis Pasteur, Colmar (France)

    1998-03-01

    Methanol, a highly toxic substance, is used as an industrial solvent and in automobile antifreeze. Acute methanol poisoning produces severe metabolic acidosis and serious neurologic sequelae. We describe a 50-year-old woman with accidental methanol intoxication who was in a vegetative state. MRI showed haemorrhagic necrosis of the putamina and oedema in the deep white matter. (orig.) With 1 fig., 8 refs.

  15. The effect of acid strength on the MTO reaction : Conversion of methanol to hydrocarbons over H-SAPO-34 and high silica Chabazite (H-SSZ-13)

    OpenAIRE

    Bleken, Francesca

    2007-01-01

    The Methanol-to-Olefins (MTO) process for the production of polymer-grade olefins is a possible step in the upgrading of natural gas. The preferred MTO catalyst is the microporous silicoaluminophosphate H-SAPO-34 (CHA topology). In the present work, H-SAPO-34 is compared with H-SSZ-13 which has the same topology and density of acid sites, but is slightly more acidic due to the framework composition. This is a one-parameter study where the effect of acidity on the MTO-process is ...

  16. Preparation and Luminous Characters of High Pure Thallium Iodide%高纯碘化铊的制备及其发光特性

    Institute of Scientific and Technical Information of China (English)

    杨桂林; 何华强

    2001-01-01

    High pure thallium iodide was made through the process of dissolving thallium in nitric acid, precipitating thallium ion by potassium iodide then subliming thallium iodide in vacuum. A series of spherical composite halides containing thallium iodide was made. Thallium iodide is used as green luminous material. It is also used as addition agent contained in composite halides of thallium iodide for different forms of application. Luminous characters of thallium iodide used as luminous material in metal halide lamps are presented.%以金属铊为原料,用硝酸溶解-碘化钾沉淀-真空升华的方法制备了高纯碘化铊,并且制备出多种球形碘化铊复合卤化物。碘化铊既可以单独用作绿光材料,也可以作为添加剂与其它金属卤化物复合得到复合金属卤化物发光材料,满足不同的使用要求。文章用图表介绍了碘化铊用作金属卤化物灯发光材料时的发光特性。

  17. Optimization of a high-throughput CTAB-based protocol for the extraction of qPCR-grade DNA from rumen fluid, plant and bacterial pure cultures.

    Science.gov (United States)

    Minas, Konstantinos; McEwan, Neil R; Newbold, Charles Jamie; Scott, Karen P

    2011-12-01

    The quality and yield of extracted DNA are critical for the majority of downstream applications in molecular biology. Moreover, molecular techniques such as quantitative real-time PCR (qPCR) are becoming increasingly widespread; thus, validation and cross-laboratory comparison of data require standardization of upstream experimental procedures. DNA extraction methods depend on the type and size of starting material(s) used. As such, the extraction of template DNA is arguably the most significant variable when cross-comparing data from different laboratories. Here, we describe a reliable, inexpensive and rapid method of DNA purification that is equally applicable to small or large scale or high-throughput purification of DNA. The protocol relies on a CTAB-based buffer for cell lysis and further purification of DNA with phenol : chloroform : isoamyl alcohol. The protocol has been used successfully for DNA purification from rumen fluid and plant cells. Moreover, after slight alterations, the same protocol was used for large-scale extraction of DNA from pure cultures of Gram-positive and Gram-negative bacteria. The yield of the DNA obtained with this method exceeded that from the same samples using commercial kits, and the quality was confirmed by successful qPCR applications.

  18. DIRECT PREPARATION OF HIGH PURE γ-ALUMINA FROM SODIUM ALUMINATE%由偏铝酸钠直接制取高纯γ-Al2O3

    Institute of Scientific and Technical Information of China (English)

    高建峰; 徐春彦; 王建中; 王久芬; 庄源益

    2003-01-01

    The purification of mother liquor containing sodium aluminate by using desilication agent and the preparation of high pure pseudo-boehmite and gamma alumina are reported. The sodium aluminate in the mother liquor coming from Shanxi Aluminium Plant is treated with home-made desilication agent, the ratios of SiO2/Al2O3 and Fe2Oa/Al2O3 in treated-solution are below 0.01%. The pseudo-boehmite is obtained with buffer solution deposition in which ammonia gas acts as a circulating medium. The specific surface area of pseudo-boehime powder reaches up to 300m2·g-1 and pore volume reaches about 0.7 ml·g-1. The content of sodium in pseudo-boehime is below 0. 005% after treating the pseudo-boehime with a sodium removal agent. The quality of this product is comparable to the SB powder made in Germany.Gamma alumina with a larger specific surface area and pore volume is obtained by temperature programmed calcination of pseudo-boehmite.

  19. Pure, single phase, high crystalline, chamfered-edge zeolite 4A synthesized from coal fly ash for use as a builder in detergents.

    Science.gov (United States)

    Hui, K S; Chao, C Y H

    2006-09-01

    Single phase chamfered-edge zeolite 4A samples in pure form with a high crystallinity were synthesized by applying step-change of synthesis temperature during hydrothermal treatment of coal fly ash. The calcium binding capacity of these zeolite 4A samples (prepared from coal fly ash) and the commercial detergent grade zeolite 4A were tested for usage as a detergent builder. The results show that these zeolite 4A samples behaved similarly as the commercial one in removing calcium ions during the washing cycle. Moreover, from the leaching tests (evaluation of toxicological safety), the results show that these zeolite 4A samples leached the same elements (Sb, As, Se and Tl) as the commercial one with the concentrations in the same order of magnitude. This shows that the toxicological effect of the coal fly ash converted zeolite 4A was not worse than that of the commercial sample. Finally, economic and environmental aspects of converting coal fly ash to useful products were discussed.

  20. Hydride-vapor-phase epitaxial growth of highly pure GaN layers with smooth as-grown surfaces on freestanding GaN substrates

    Science.gov (United States)

    Fujikura, Hajime; Konno, Taichiro; Yoshida, Takehiro; Horikiri, Fumimasa

    2017-08-01

    Thick (20-30 µm) layers of highly pure GaN with device-quality smooth as-grown surfaces were prepared on freestanding GaN substrates by using our advanced hydride-vapor-phase epitaxy (HVPE) system. Removal of quartz parts from the HVPE system markedly reduced concentrations of residual impurities to below the limits of detection by secondary-ion mass spectrometry. Appropriate gas-flow management in the HVPE system realized device-quality, smooth, as-grown surfaces with an excellent uniformity of thickness. The undoped GaN layer showed insulating properties. By Si doping, the electron concentration could be controlled over a wide range, down to 2 × 1014 cm-3, with a maximum mobility of 1150 cm2·V-1·s-1. The concentration of residual deep levels in lightly Si-doped layers was in the 1014 cm-3 range or less throughout the entire 2-in. wafer surface. These achievements clearly demonstrate the potential of HVPE as a tool for epitaxial growth of power-device structures.

  1. Enhanced porcine circovirus Cap protein production by Pichia pastoris with a fuzzy logic DO control based methanol/sorbitol co-feeding induction strategy.

    Science.gov (United States)

    Ding, Jian; Zhang, Chunling; Gao, Minjie; Hou, Guoli; Liang, Kexue; Li, Chunhua; Ni, Jianping; Li, Zhen; Shi, Zhongping

    2014-05-10

    Porcine circovirus Cap protein production by P. pastoris with strong AOX promoter suffered with the problems with traditional pure methanol induction: (1) inefficient methanol metabolism; (2) extensive oxygen supply load; (3) difficulty in stable DO control; (4) low protein titer. In this study, based on the difference of DO change patterns in response to methanol and sorbitol additions, a novel fuzzy control system was proposed to automatically regulate the co-feeding rates of methanol and sorbitol for efficient Cap protein induction. With aid of the proposed control system when setting DO control level at 10%, overall fermentation performance was significantly improved: (1) DO could be stably controlled under mild aeration condition; (2) methanol consumption rate could be restricted at moderate level and the major enzymes involved with methanol metabolism were largely activated; (3) Cap protein concentration reached a highest level of 198mg/L, which was about 64% increase over the best one using the pure methanol induction strategies.

  2. Methanol emission from low mass protostars

    CERN Document Server

    Maret, S; Tielens, A G G M; Caux, E; Le Floc'h, B; Faure, A; Castets, A; Flower, D R

    2005-01-01

    We present observations of methanol lines in a sample of Class 0 low mass protostars. Using a 1-D radiative transfer model, we derive the abundances in the envelopes. In two sources of the sample, the observations can only be reproduced by the model if the methanol abundance is enhanced by about two order of magnitude in the inner hot region of the envelope. Two other sources show similar jumps, although at a lower confidence level. The observations for the other three sources are well reproduced with a constant abundance, but the presence of a jump cannot be ruled out. The observed methanol abundances in the warm gas around low mass protostars are orders of magnitude higher than gas phase chemistry models predict. Hence, in agreement with other evidences, this suggest that the high methanol abundance reflects recent evaporation of ices due to the heating by the newly formed star. The observed abundance ratios of CH3 OH, H2 CO, and CO are in good agreement with grain surface chemistry models. However, the abs...

  3. Dahlbeck and Pure Ontology

    Science.gov (United States)

    Mackenzie, Jim

    2016-01-01

    This article responds to Johan Dahlbeck's "Towards a pure ontology: Children's bodies and morality" ["Educational Philosophy and Theory," vol. 46 (1), 2014, pp. 8-23 (EJ1026561)]. His arguments from Nietzsche and Spinoza do not carry the weight he supposes, and the conclusions he draws from them about pedagogy would be…

  4. Dahlbeck and Pure Ontology

    Science.gov (United States)

    Mackenzie, Jim

    2016-01-01

    This article responds to Johan Dahlbeck's "Towards a pure ontology: Children's bodies and morality" ["Educational Philosophy and Theory," vol. 46 (1), 2014, pp. 8-23 (EJ1026561)]. His arguments from Nietzsche and Spinoza do not carry the weight he supposes, and the conclusions he draws from them about pedagogy would be…

  5. 废气再循环对高比例甲醇双燃料柴油机燃烧过程的影响%Influence of EGR on Combustion Process in High Methanol Proportion Dual Fuel Diesel Engine

    Institute of Scientific and Technical Information of China (English)

    李仁春; 王忠; 张登攀; 李铭迪

    2014-01-01

    在4B26增压柴油机上,以进气管电控喷射的方式掺入甲醇,实现甲醇/柴油双燃料的燃烧。采用废气再循环技术拓宽高比例甲醇双燃料柴油机的工况范围,研究EGR对燃烧过程的影响规律。结果表明:适当的EGR率可以显著降低燃烧初期时的燃烧反应速度和加速度,缸内燃烧压力振荡明显减弱。随着EGR率的增加,甲醇/柴油预混合燃烧量减少,滞燃期缩短,燃烧持续期延长,燃烧最高温度降低;原甲醇/柴油双燃料燃烧放热以预混放热为主;引入EGR后,预混放热量减少,扩散放热量增加。随着EGR率的增加,放热率峰值降低;在相同工况下,保持掺混48%甲醇不变时,甲醇/柴油双燃料发动机的指示热效率随EGR率的增加而降低。%Methanol/diesel dual fuel combustion is realized on a turbocharged diesel engine 4B26 with methanol blended in by electronically controlled intake port injection. Exhaust gas recirculation ( EGR) technology is adopted to extend the working range of dual fuel diesel engine with high proportion of methanol with its effects on combustion process studied. The results show that an appropriate EGR rate can significantly reduce the speed and acceleration of combustion reaction at initial stage and weaken the oscillation of in-cylinder combustion pressure. With the increase in EGR rate, the volume of premixed combustion of methanol/diesel blend reduces, ignition delay period shortens, combustion duration prolongs and the combustion temperature peak lowers. The main parts of heat release is premixed one for methanol/diesel dual fuel combustion in nature, but with EGR introduced, premixed heat release reduces, diffusion heat release increases, and the peak heat release rate lowers when EGR rate increa-ses. In the same working condition with a fixed methanol proportion of 48%, the indicated thermal efficiency of methanol/diesel duel fuel engine lowers with the increase of

  6. Modification of platinum surfaces by spontaneous deposition: Methanol oxidation electrocatalysis

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, J.P.; Gualtieri, B.; Runga, N.; Teliz, E.; Zinola, C.F. [Fundamental Electrochemistry Laboratory, School of Sciences, Universidad de la Republica, Igua Street No. 4225, CP 11400, Montevideo (Uruguay)

    2008-12-15

    The presence of a second metal on platinum surfaces affects the performance of methanol oxidation. However, most of the electrocatalytic reactions are studied by using electrochemically deposited platinum alloys, but in the case of spontaneous deposition the situation is not so clear since the surface distribution, stability and morphology are usually not well documented. The formation of surface decorated samples on mono- and poly-crystalline platinum is followed by electrochemical and spectroscopic techniques and analysis of their performance towards methanol adsorption and oxidation compared with that on pure platinum. Pt/Sn and Pt/Ru are of special interest because of their well-known performance in methanol fuel cells. Methanol oxidation on Pt(111)/Ru, Pt(111)/Sn and Pt(111) shows that ruthenium is the only one able to promote the reaction since the simultaneous dissolution of tin occurs and competes with the process of interest. The in situ infrared spectroscopy is used to compare methanol oxidation on Pt(111)/Ru and Pt(111) in acid media using p-polarized light. The formation of bridge bound carbon monoxide is inhibited in the presence of ruthenium ad-species, whereas on Pt(111) the three adsorption configurations are observed. Linear sweep polarization curves and Tafel slopes (calculated from steady state potentiostatic plots) for methanol oxidation are compared on polycrystalline surfaces modified by tin or ruthenium at different coverages. There is almost no change in the Tafel slopes due to the presence of the foreign metal except for Pt/Ru, where a 0.09 V decade{sup -1} slope was calculated below 0.55 V due to hydroxyl adsorbates on ruthenium islands. The anodic stripping of methanol residues on the three surfaces indicates a lower amount of carbon monoxide-type adsorbates on Pt/Ru, and the simultaneous tin dissolution process leading to residues oxidation on Pt/Sn electrodes. (author)

  7. Fabrication of Yolk-Shell Cu@C Nanocomposites as High-Performance Catalysts in Oxidative Carbonylation of Methanol to Dimethyl Carbonate

    Science.gov (United States)

    Wang, Juan; Hao, Panpan; Shi, Ruina; Yang, Leilei; Liu, Shusen; Zhao, Jinxian; Ren, Jun; Li, Zhong

    2017-08-01

    A facile way was developed to fabricate yolk-shell composites with tunable Cu cores encapsulated within hollow carbon spheres (Cu@C) with an average diameter about 210 nm and cavity size about 80 nm. During pyrolysis, the confined nanospace of hollow cavity ensures that the nucleation-and-growth process of Cu nanocrystals take place exclusively inside the cavities. The size of Cu cores can be easily tuned from 30 to 55 nm by varying the copper salt concentration. By deliberately creating shell porosity through KOH chemical activation, at an optimized KOH/HCS mass ratio of 1/4, the catalytic performance for the oxidative carbonylation of methanol to dimethyl carbonate (DMC) of the activated sample is enhanced remarkably with TOF up to 8.6 h-1 at methanol conversion of 17.1%. The activated yolk-shell catalyst shows promising catalytic properties involving the reusability with slight loss of catalytic activity and negligible leaching of activated components even after seven recycles, which is beneficial to the implementation of clean production for the eco-friendly chemical DMC thoroughly.

  8. Studies on an ultrasonic atomization feed direct methanol fuel cell.

    Science.gov (United States)

    Wu, Chaoqun; Liu, Linghao; Tang, Kai; Chen, Tao

    2017-01-01

    Direct methanol fuel cell (DMFC) is promising as an energy conversion device for the replacement of conventional chemical cell in future, owing to its convenient fuel storage, high energy density and low working temperature. The development of DMFC technology is currently limited by catalyst poison and methanol crossover. To alleviate the methanol crossover, a novel fuel supply system based on ultrasonic atomization is proposed. Experimental investigations on this fuel supply system to evaluate methanol permeation rates, open circuit voltages (OCVs) and polarization curves under a series of conditions have been carried out and reported in this paper. In comparison with the traditional liquid feed DMFC system, it can be found that the methanol crossover under the ultrasonic atomization feed system was significantly reduced because the DMFC reaches a large stable OCV value. Moreover, the polarization performance does not vary significantly with the liquid feed style. Therefore, the cell fed by ultrasonic atomization can be operated with a high concentration methanol to improve the energy density of DMFC. Under the supply condition of relatively high concentration methanol such as 4M and 8M, the maximum power density fed by ultrasonic atomization is higher than liquid by 6.05% and 12.94% respectively.

  9. Purification of methanol dehydrogenase from mouth methylotrophic bacteria of tropical region

    OpenAIRE

    Waturangi, D.; Marko, N.; M. T. Suhartono2)

    2011-01-01

    Aims: Purification of methanol dehydrogenase (MDH) from methylotrophic bacteria was conducted to obtain pure enzyme for further research and industrial applications due to the enzyme’s unique activity that catalyzes oxidation of methanol as an important carbon source in methylotrophic bacteria.Methodology and Results: The enzyme was screened from methylotrophic bacteria isolated from human mouth. Purification of this enzyme was conducted using ammonium sulphate precipitation followed by catio...

  10. Noble metal nanowires incorporated Nafion {sup registered} membranes for reduction of methanol crossover in direct methanol fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Z.X.; Liao, S.J.; Zeng, J.H. [School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510641 (China); Shi, J.Y. [School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275 (China)

    2010-09-15

    We electrodeposited noble metal (palladium, platinum) nanowires into the hydrophilic pores of Nafion membrane for mitigating the problem of methanol crossover in direct methanol fuel cells (DMFCs). The DMFC performance result shows that the composite membranes yield lower rate of methanol crossover and better cell performance than the pure Nafion {sup registered} membrane. At low current densities, the Pd nanowire incorporated Nafion membrane shows the best performance. In comparison, the highest performance is achieved at higher current densities with the Pt nanowire modified Nafion membrane. Based on the above findings, we suggest that for the Pd nanowire incorporated Nafion membrane, the mechanism for the suppression of the methanol crossover is mainly the blocking effect due to the 'narrowed' hydrophilic channels in Nafion membrane. For the Pt nanowire modified Nafion membrane, the mechanism includes both increasing the membrane tortuosity and so-called 'on-way consumption' of methanol on the Pt nanowires deposited into the Nafion membrane when the fuel cell is discharging. (author)

  11. Comparison of the effectiveness of monitoring Cisplatin-induced ototoxicity with extended high-frequency pure-tone audiometry or distortion-product otoacoustic emission.

    Science.gov (United States)

    Yu, Kwang Kyu; Choi, Chi Ho; An, Yong-Hwi; Kwak, Min Young; Gong, Soo Jung; Yoon, Sang Won; Shim, Hyun Joon

    2014-09-01

    To compare the effectiveness of monitoring cisplatin-induced ototoxicity in adult patients using extended high-frequency pure-tone audiometry (EHF-PTA) or distortion-product otoacoustic emission (DP-OAE) and to evaluate the concurrence of ototoxicity and nephrotoxicity in cisplatin-treated patients. EHF-PTA was measured at frequencies of 0.25, 0.5, 1, 2, 3, 4, 6, 8, 9, 11.2, 12.5, 14, 16, 18, and 20 kHz and DP-OAE at frequencies of 0.5, 0.75, 1, 1.5, 2, 3, 4, 6, and 8 kHz in cisplatin-treated patients (n=10). Baseline evaluations were made immediately before chemotherapy and additional tests were performed before each of six cycles of cisplatin treatment. Laboratory tests to monitor nephrotoxicity were included before every cycle of chemotherapy. Four of 10 patients showed threshold changes on EHF-PTA. Five of 10 patients showed reductions in DP-OAE, but one was a false-positive result. The results of EHF-PTA and DP-OAE were consistent in two patients. Only one patient displayed nephrotoxicity on laboratory tests after the third cycle. In our study, the incidence rate of cisplatin-induced ototoxicity was 40% with EHF-PTA or DP-OAE. Although both EHF-PTA and DP-OAE showed the same sensitivity in detecting ototoxicity, they did not produce the same results in all patients. These two hearing tests could be used to complement one another. Clinicians should use both tests simultaneously in every cycle of chemotherapy to ensure the detection of ototoxicity.

  12. Empirical model based on Weibull distribution describing the destruction kinetics of natural microbiota in pineapple (Ananas comosus L.) puree during high-pressure processing.

    Science.gov (United States)

    Chakraborty, Snehasis; Rao, Pavuluri Srinivasa; Mishra, Hari Niwas

    2015-10-15

    High pressure inactivation of natural microbiota viz. aerobic mesophiles (AM), psychrotrophs (PC), yeasts and molds (YM), total coliforms (TC) and lactic acid bacteria (LAB) in pineapple puree was studied within the experimental domain of 0.1-600 MPa and 30-50 °C with a treatment time up to 20 min. A complete destruction of yeasts and molds was obtained at 500 MPa/50 °C/15 min; whereas no counts were detected for TC and LAB at 300 MPa/30 °C/15 min. A maximum of two log cycle reductions was obtained for YM during pulse pressurization at the severe process intensity of 600 MPa/50 °C/20 min. The Weibull model clearly described the non-linearity of the survival curves during the isobaric period. The tailing effect, as confirmed by the shape parameter (β) of the survival curve, was obtained in case of YM (β1) was observed for the other microbial groups. Analogous to thermal death kinetics, the activation energy (Ea, kJ·mol(-1)) and the activation volume (Va, mL·mol(-1)) values were computed further to describe the temperature and pressure dependencies of the scale parameter (δ, min), respectively. A higher δ value was obtained for each microbe at a lower temperature and it decreased with an increase in pressure. A secondary kinetic model was developed describing the inactivation rate (k, min(-1)) as a function of pressure (P, MPa) and temperature (T, K) including the dependencies of Ea and Va on P and T, respectively.

  13. Purely Functional Structured Programming

    OpenAIRE

    Obua, Steven

    2010-01-01

    The idea of functional programming has played a big role in shaping today's landscape of mainstream programming languages. Another concept that dominates the current programming style is Dijkstra's structured programming. Both concepts have been successfully married, for example in the programming language Scala. This paper proposes how the same can be achieved for structured programming and PURELY functional programming via the notion of LINEAR SCOPE. One advantage of this proposal is that m...

  14. Purely Cortical Anaplastic Ependymoma

    Directory of Open Access Journals (Sweden)

    Flávio Ramalho Romero

    2012-01-01

    Full Text Available Ependymomas are glial tumors derived from ependymal cells lining the ventricles and the central canal of the spinal cord. It may occur outside the ventricular structures, representing the extraventicular form, or without any relationship of ventricular system, called ectopic ependymona. Less than fifteen cases of ectopic ependymomas were reported and less than five were anaplastic. We report a rare case of pure cortical ectopic anaplastic ependymoma.

  15. Purely tetrahedral quadruple systems

    Institute of Scientific and Technical Information of China (English)

    JI Lijun

    2006-01-01

    An oriented tetrahedron is a set of four vertices and four cyclic triples with the property that any ordered pair of vertices is contained in exactly one of the cyclic triples. A tetrahedral quadruple system of order n (briefly TQS(n)) is a pair (X,B), where X is an nelement set and B is a set of oriented tetrahedra such that every cyclic triple on X is contained in a unique member of B. A TQS(n) (X, B) is pure if there do not exist two oriented tetrahedra with the same vertex set. In this paper, we show that there is a pure TQS(n) if and only if n≡2,4(mod 6),n>4,or n≡1,5(mod 12). One corollary is that there is a simple two-fold quadruple system of order n if and only if n≡2,4 (mod 6) and n>4, or n≡1, 5 (mod 12).Another corollary is that there is an overlarge set of pure Mendelsohn triple systems of order n for n≡1,3(mod 6),n>3, or n≡0,4 (mod 12).

  16. Influence of the Synthesis Method for Pt Catalysts Supported on Highly Mesoporous Carbon Xerogel and Vulcan Carbon Black on the Electro-Oxidation of Methanol

    Directory of Open Access Journals (Sweden)

    Cinthia Alegre

    2015-03-01

    Full Text Available Platinum catalysts supported on carbon xerogel and carbon black (Vulcan were synthesized with the aim of investigating the influence of the characteristics of the support on the electrochemical performance of the catalysts. Three synthesis methods were compared: an impregnation method with two different reducing agents, sodium borohydride and formic acid, and a microemulsion method, in order to study the effect of the synthesis method on the physico-chemical properties of the catalysts. X-ray diffraction and transmission electron microscopy were applied. Cyclic voltammetry and chronoamperometry were used for studying carbon monoxide and methanol oxidation. Catalysts supported on carbon xerogel presented higher catalytic activities towards CO and CH3OH oxidation than catalysts supported on Vulcan. The higher mesoporosity of carbon xerogel was responsible for the favored diffusion of reagents towards catalytic centers.

  17. Facile synthesis of highly active reduced graphene oxide-CuI catalyst through a simple combustion method for photocatalytic reduction of CO2 to methanol

    Science.gov (United States)

    Zhang, Wenjun; Li, Yingjie; Zhang, Xiaoxiong; Li, Cuiluo

    2017-09-01

    We report a facile combustion method synthesis of reduced graphene oxide/CuI composites as a photocatalyst, in which CuI nanoparticles were homogeneously distributed on the surface of reduced graphene oxide (rGO), showing a good visible light response. The rGO-supported and unsupported CuI hybrids were tested over the photocatalytic reduction of CO2 for methanol evolution in visible light. In the current study rGO-CuI composites have shown excellent yields (19.91 μmol g-cat-1). rGO provides a light-weight, charge complementary and two-dimensional material that interacts effectively with the CuI nanoparticles.

  18. A closer study of methanol adsorption and its impact on solute retentions in supercritical fluid chromatography.

    Science.gov (United States)

    Glenne, Emelie; Öhlén, Kristina; Leek, Hanna; Klarqvist, Magnus; Samuelsson, Jörgen; Fornstedt, Torgny

    2016-04-15

    Surface excess adsorption isotherms of methanol on a diol silica adsorbent were measured in supercritical fluid chromatography (SFC) using a mixture of methanol and carbon dioxide as mobile phase. The tracer pulse method was used with deuterium labeled methanol as solute and the tracer peaks were detected using APCI-MS over the whole composition range from neat carbon dioxide to neat methanol. The results indicate that a monolayer (4Å) of methanol is formed on the stationary phase. Moreover, the importance of using the set or the actual methanol fractions and volumetric flows in SFC was investigated by measuring the mass flow respective pressure and by calculations of the actual volume fraction of methanol. The result revealed a significant difference between the value set and the actually delivered volumetric methanol flow rate, especially at low modifier fractions. If relying only on the set methanol fraction in the calculations, the methanol layer thickness should in this system be highly overestimated. Finally, retention times for a set of solutes were measured and related to the findings summarized above concerning methanol adsorption. A strongly non-linear relationship between the logarithms of the retention factors and the modifier fraction in the mobile phase was revealed, prior to the established monolayer. At modifier fractions above that required for establishment of the methanol monolayer, this relationship turns linear which explains why the solute retention factors are less sensitive to changes in modifier content in this region.

  19. Short Review: Mitigation of Current Environmental Concerns from Methanol Synthesis

    Directory of Open Access Journals (Sweden)

    Andrew Young

    2013-06-01

    Full Text Available Methanol has become a widely used and globally distributed product. Methanol is very important due to the current depletion of fossil fuels. Industrially, methanol produced from the catalytic reaction of synthetic gas composed of hydrogen, carbon monoxide, and carbon dioxide. Methanol production has brought great attention due to carbon dioxide as the main source of greenhouse gas emissions. Combined of reducing CO2 emissions and supplying an alternative fuel source has created the idea of a carbon neutral cycle called “the methanol economy”. The best catalyst for the methanol economy would show a high CO2 conversion and high selectivity for methanol production. This paper investigates research focused on catalyst development for efficient methanol synthesis from hydrogenation of carbon dioxide through added various supports and additives such as silica, zirconium, and palladium. Catalysts that displayed the highest activity included a zirconia and silicon-titanium oxide promoted Cu/Zn/Al2O3 catalyst. Alternative method of catalyst preparation, include the oxalate-gel, solid-state reaction, co-precipitation and combustion method also investigated.  © 2013 BCREC UNDIP. All rights reservedReceived: 10th October 2012; Revised: 7th February 2012; Accepted: 10th February 2013[How to Cite: Young, A., Lesmana, D., Dai, D.J., Wu, H.S. (2013. Short Review: Mitigation of Current En-vironmental Concerns from Methanol Synthesis. Bulletin of Chemical Reaction Engineering & Catalysis, 8 (1: 1-13. (doi:10.9767/bcrec.8.1.4055.1-13][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.8.1.4055.1-13] | View in  |

  20. Mutagenic and cytotoxic activities of Limonium globuliferum methanol extracts.

    Science.gov (United States)

    Eren, Yasin

    2016-10-01

    Unmonitored use of plant extractions alone or in combination with drugs may cause important health problems and toxic effects. Limonium (Plumbaginaceae) plants are known as antibacterial, anticancer and antivirus agent. But it is possible that this genus may have toxic effects. This study evaluated the mutagenic and cytotoxic effects of Limonium globuliferum (Boiss. et Heldr.) O. Kuntze (Plumbaginaceae) acetone/methanol (2:1), and methanol extracts of root, stem, and leaf. Different parts of this species were used in order to compare the mutagenic and cytotoxic effects of these parts. Ames test was carried out with S. typhimurium TA98, and TA100 strains. Strains were incubated at 37 °C for 72 h. MDBK cell line was used in MTT test. 10,000, 1000, 100, 10, 1 and 0.1 µg/plate concentrations of plant extracts were used in Ames test. 50, 25, 12.5, 6.25 and 3.125 µg/ml concentrations of root, stem and leaf acetone/methanol (2:1) and methanol extracts were used in MTT test. Ames test results indicated that only methanol leaf extract (10,000 µg/plate) had mutagenic activity. L. globuliferum root methanol extracts (3.125 and 6.25 µg/ml) increased the proliferation rates. Root acetone/methanol (2:1) extracts were found highly cytotoxic in all treatments. The results indicated that leaf extracts had lower cytotoxic effects than root and stem extracts. High concentrations of L. globuliferum stem and leaf methanol extracts showed cytotoxic activity in all treatment periods while low concentrations of the stem methanol extracts increased the proliferation rates.

  1. Acute methanol toxicity in minipigs

    Energy Technology Data Exchange (ETDEWEB)

    Dorman, D.C.; Dye, J.A.; Nassise, M.P.; Ekuta, J.; Bolon, B.

    1993-01-01

    The pig has been proposed as a potential animal model for methanol-induced neuro-ocular toxicosis in humans because of its low liver tetrahydrofolate levels and slower rate of formate metabolism compared to those of humans. To examine the validity of this animal model, 12 4-month-old female minipigs (minipig YU) were given a single oral dose of water or methanol at 1.0, 2.5, or 5.0 g/kg body wt by gavage (n = 3 pigs/dose). Dose-dependent signs of acute methanol intoxication, which included mild CNS depression, tremors, ataxia, and recumbency, developed within 0.5 to 2.0 hr, and resolved by 52 hr. Methanol- and formate-dosed pigs did not develop optic nerve lesions, toxicologically significant formate accumulation, or metabolic acidosis. Based on results following a single dose, female minipigs do not appear to be overtly sensitive to methanol and thus may not be a suitable animal model for acute methanol-induced neuroocular toxicosis.

  2. Activity measurements of the high-energy pure beta-emitters Sr-89 and Y-90 by the TDCR efficiency calculation technique

    CSIR Research Space (South Africa)

    Simpson, BRS

    2006-10-01

    Full Text Available The absolute activities of the pure beta-emitters Sr-89 and Y-90 have been determined by a direct method, namely the triple-to-double coincidence ratio (TDCR) efficiency calculation technique. This undertaking has extended further the number...

  3. Comparison of early and late results of a Carbofilm-coated stent versus a pure high-grade stainless steel stent (the Carbostent-Trial).

    NARCIS (Netherlands)

    Sick, P.B.; Gelbrich, G.; Kalnins, U.; Erglis, A.; Bonan, R.; Aengevaeren, W.R.M.; Elsner, D.; Lauer, B.; Woinke, M.; Brosteanu, O.; Schuler, G.

    2004-01-01

    The long-term success of coronary interventions with stents is largely determined by the development of restenosis. The aim of this study was to compare a Carbofilm-coated and a pure stainless steel stent with regard to early and late adverse events. In this prospective, randomized trial, the Carbof

  4. Clinical performance of the new Roche COBAS (R) TaqMan HCV test and high pure system for extraction, detection and quantitation of HCV RNA in plasma and serum

    NARCIS (Netherlands)

    H.C. Gelderblom; S. Menting; M.G. Beld

    2006-01-01

    We evaluated the Roche COBAS (R) TaqMan HCV Test For Use With The High Pure System (TaqMan HPS; Roche Diagnostics), for the extraction, detection and quantitation of hepatitis C virus (HCV) RNA in serum or plasma of HCV-infected individuals. The TaqMan HPS is a real-time PCR assay with a reported li

  5. Visualizing ignition and combustion of methanol mixtures in a diesel engine; Methanol funmu no glow chakka to nensho no kashika

    Energy Technology Data Exchange (ETDEWEB)

    Inomoto, Y.; Harada, T.; Kusaka, J.; Daisho, Y.; Kihara, R.; Saito, T. [Waseda University, Tokyo (Japan)

    1997-10-01

    A glow-assisted ignition system tends to suffer from poor ignitability and slow flame propagation at low load in a direct-injection diesel engine fueled with methanol. To investigate the ignition process and improve such disadvantages, methanol sprays, their ignition and flames were visualized at high pressures and temperatures using a modified two-stroke engine. The results show that parameters influencing ignition, the location of a glow-plug, swirl level, pressure and temperature are important. In addition, a full kinetics calculation was conducted to predict the delay of methanol mixture ignition by taking into account 39 chemical species and 157 elementary reactions. 3 refs., 9 figs.

  6. Methanol oxidation at platinized copper particles prepared by galvanic replacement

    Directory of Open Access Journals (Sweden)

    Ioanna Mintsouli

    2016-04-01

    Full Text Available Bimetallic Pt-Cu particles have been prepared by galvanic replacement of Cu precursor nanoparticles, upon the treatment of the latter with a chloro-platinate acidic solution. The resulting particles, typically a few tens of nm large, were supported on high surface area carbon (Vulcan® XC–72R, Cabot and tested as electrodes. Surface electrochemistry in deaerated acid solutions was similar to that of pure Pt, indicating the existence of a Pt shell (hence the particles are denoted as Pt(Cu. Pt(Cu/C supported catalysts exhibit superior carbon monoxide and methanol oxidation activity with respect to their Pt/C analogues when compared on a per electroactive surface area basis, due to the modification of Pt activity by Cu residing in the particle core. However, as a result of large particle size and agglomeration phenomena, Pt(Cu/C are still inferior to Pt/C when compared on a mass specific activity basis.

  7. PURE DRIVE GT

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    在2004年奥林匹克赛事中,中国的李婷,孙甜甜取得了中国网球第一个金牌一女子双打冠军。忘记不了当时李婷挥动着她的BABOLAT(百保力)网拍Pure Drive Zylon 360°激动地拥抱着孙甜甜吵闹着,幸福地哭着的情景。

  8. Pure de Sitter Supergravity

    CERN Document Server

    Bergshoeff, Eric A; Kallosh, Renata; Van Proeyen, Antoine

    2015-01-01

    Using superconformal methods we derive an explicit de Sitter supergravity action invariant under spontaneously broken local ${\\cal N}=1$ supersymmetry. The supergravity multiplet interacts with a nilpotent goldstino multiplet. We present a complete locally supersymmetric action including the graviton and the fermionic fields, gravitino and goldstino, no scalars. In the global limit when supergravity multiplet decouples, our action reproduces the Volkov-Akulov theory. In the unitary gauge where goldstino vanishes we recover pure supergravity with the positive cosmological constant. The classical equations of motion, with all fermions vanishing, have a maximally symmetric solution: de Sitter space.

  9. Low content of Pt supported on Ni-MoCx/carbon black as a highly durable and active electrocatalyst for methanol oxidation, oxygen reduction and hydrogen evolution reactions in acidic condition

    Science.gov (United States)

    Zhang, Yan; Zang, Jianbing; Jia, Shaopei; Tian, Pengfei; Han, Chan; Wang, Yanhui

    2017-08-01

    Nickel and molybdenum carbide modified carbon black (Ni-MoCx/C) was synthesized by a two-step microwave-assisted deposition/carbonthermal reduction method and characterized by X-ray diffraction, transmission electron microscopy, energy dispersive spectroscopy and X-ray photoelectron spectroscopy. The as-prepared Ni-MoCx/C supported Pt (10 wt%) electrocatalyst (10Pt/Ni-MoCx/C) was synthesized through a microwave-assisted reduction method and 10Pt/Ni-MoCx/C exhibited high electrocatalytic activity for methanol oxidation, oxygen reduction and hydrogen evolution reactions. Results showed that 10Pt/Ni-MoCx/C electrocatalyst had better electrocatalytic activity and stability performance than 20 wt% Pt/C (20Pt/C) electrocatalyst. Among them, the electrochemical surface area of 10Pt/Ni-MoCx/C reached 68.4 m2 g-1, which was higher than that of 20Pt/C (63.2 m2 g-1). The enhanced stability and activity of 10Pt/Ni-MoCx/C electrocatalyst were attributed to: (1) an anchoring effect of Ni and MoCx formed during carbonthermal reduction process; (2) a synergistic effect among Pt, Ni, MoOx and MoCx. These findings indicated that 10Pt/Ni-MoCx/C was a promising electrocatalyst for direct methanol fuel cells.

  10. High activity of carbon nanotubes supported binary and ternary Pd-based catalysts for methanol, ethanol and formic acid electro-oxidation

    Science.gov (United States)

    Zhu, Fuchun; Ma, Guanshui; Bai, Zhongchao; Hang, Ruiqiang; Tang, Bin; Zhang, Zhonghua; Wang, Xiaoguang

    2013-11-01

    In this study, we have synthesized a series of multi-walled carbon nanotubes supported Pd, PdCu(molar ratio 1:1), PdSn(1:1) and PdCuSn(1:1:1) catalysts by chemical reduction with NaBH4 as a reducing agent. These catalysts are characterized using X-ray diffraction, transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy (XPS), cyclic voltammetry and chronoamperometry. During the potential cycling activation, it is found that the additive Cu is prone to suffer leaching while the dissolution of Sn rarely occurs. Electrochemical measurements demonstrate that, the co-alloying of Pd with Cu and Sn can trigger the best catalytic activity enhancement as compared with the binary PdCu/CNTs, PdSn/CNTs and mono-component Pd/CNTs catalysts. The PdCuSn/CNTs reveals the most excellent activities toward methanol, ethanol and formic acid electro-oxidation and the corresponding mass activity can attain to 395.94, 872.70 and 534.83 mA mg-1 Pd, respectively. The possible promotion effect of additive Sn or/and Cu on the electrocatalytic activity improvement is also analyzed.

  11. Study of complex properties of binary system of ethanol-methanol at extreme concentrations

    CERN Document Server

    Nilavarasi, K; Madhurima, V

    2016-01-01

    At low concentrations of methanol in ethanol-methanol binary system, the molecular interactions are seen to be uniquely complex. It is observed that the ethanol aggregates are not strictly hydrogen-bonded complexes; dispersion forces also play a dominant role in the self- association of ethanol molecules. On the addition of small amount of methanol to ethanol, the dipolar association of ethanol is destroyed. The repulsive forces between the two moieties dominate the behavior of the binary system at lower concentration of methanol. At higher concentration of methanol (> 30%), the strength and extent (number) of formation of hydrogen bonds between ethanol and methanol increases. The geometry of molecular structure at high concentration favors the fitting of component molecules with each other. Intermolecular interactions in the ethanol-methanol binary system over the entire concentration range were investigated in detail using broadband dielectric spectroscopy, FTIR, surface tension and refractive index studies...

  12. Effect of ultra-high pressure treatment on fresh-keeping of coconut puree%超高压处理对椰肉原浆保鲜的影响

    Institute of Scientific and Technical Information of China (English)

    康蕊; 段振华; 高祥雁; 彭键; 杨毅; 成长玉

    2013-01-01

    In order to explore the appopriate preservation methods of coconut puree, coconut puree was treated under 600MPa pressure for 10min at 30℃,and then stored at 0~5℃ for 16d.Analysis was made on the effect of ultra -high pressure treatment on total bacterial count, color, pH conductivity of coconut puree during the storing period.The results showed that after ultra high pressure treatment,the growth of microorganisms was significantly inhibited.The L value, a value, b value, and conductivity decreased, pH increasesed, but they changed slowly during storing time,which to some extent retarded the change of quality of coconut puree.ln a word the ultra high pressure technology could be used in fresh-keeping of coconut puree.%为了研究适宜的椰肉原浆的保藏方法,将椰肉原浆经过600MPa压力,保压时间10min,保压温度30℃条件下处理后在0~5℃条件下贮藏16d,分析超高压处理对贮藏期间椰肉原浆的菌落总数、色泽、pH、电导率影响.结果表明:与对照组相比,超高压处理后可以明显抑制微生物的生长.L、a、b值、电导率有所下降,pH升高,但在储藏期间其变化比较缓慢,在一定程度上延缓了椰肉的品质改变.所以超高压技术是一种较好的椰肉原浆保鲜的方法.

  13. Physical characteristics of bright Class I methanol masers

    Science.gov (United States)

    Leurini, S.; Menten, K. M.; Walmsley, C. M.

    2016-07-01

    Context. Class I methanol masers are thought to be tracers of interstellar shock waves. However, they have received relatively little attention mostly as a consequence of their low luminosities compared to other maser transitions. This situation has changed recently and Class I methanol masers are now routinely used as signposts of outflow activity especially in high extinction regions. The recent detection of polarisation in Class I lines now makes it possible to obtain direct observational information about magnetic fields in interstellar shocks. Aims: We make use of newly calculated collisional rate coefficients for methanol to investigate the excitation of Class I methanol masers and to reconcile the observed Class I methanol maser properties with model results. Methods: We performed large velocity gradient calculations with a plane-parallel slab geometry appropriate for shocks to compute the pump and loss rates which regulate the interactions of the different maser systems with the maser reservoir. We study the dependence of the pump rate coefficient, the maser loss rate, and the inversion efficiency of the pumping scheme of several Class I masers on the physics of the emitting gas. Results: We predict inversion in all transitions where maser emission is observed. Bright Class I methanol masers are mainly high-temperature (>100 K) high-density (n(H2) ~ 107-108 cm-3) structures with methanol maser emission measures, ξ, corresponding to high methanol abundances close to the limits set by collisional quenching. Our model predictions reproduce reasonably well most of the observed properties of Class I methanol masers. Class I masers in the 25 GHz series are the most sensitive to the density of the medium and mase at higher densities than other lines. Moreover, even at high density and high methanol abundances, their luminosity is predicted to be lower than that of the 44 GHz and 36 GHz masers. Our model predictions also reflect the observational result that the

  14. Pure Water From a Pure Genius

    Science.gov (United States)

    2002-01-01

    Ammonium perchlorate is widely used throughout the aerospace, munitions, and pyrotechnics industries as a primary ingredient in solid rocket and missile propellants, fireworks, and explosive charges. This highly soluble salt has tainted soils and water sources all over the world, and is believed to be an endocrine disrupter, adversely affecting the growth patterns of a fetus or a young child. UMPQUA Research Company (URC), once a small drinking water testing laboratory and a research and development contractor for NASA's manned spaceflight applications, has evolved to become a leader in water purification and analysis. With a total of 11 patents issued for new technologies created by URC under NASA SBIR contracts and a 25-year commitment to water recycling, the company clearly possessed the qualifications necessary to tackle the presence of perchlorate in water. An SBIR contract with NASA's Marshall Space Flight Center that concentrated on the stringent water quality requirements of long-term, manned spaceflight was the source for URC's process and catalyst to facilitate the destruction of perchlorate and nitrate in water. URC licensed the rights of its unique reduction reaction process to Calgon Carbon Corporation for use with the company's perchlorate/nitrate remediation process, otherwise known as ISEP(R).

  15. Expander Graphs in Pure and Applied Mathematics

    OpenAIRE

    Lubotzky, Alexander

    2011-01-01

    Expander graphs are highly connected sparse finite graphs. They play an important role in computer science as basic building blocks for network constructions, error correcting codes, algorithms and more. In recent years they have started to play an increasing role also in pure mathematics: number theory, group theory, geometry and more. This expository article describes their constructions and various applications in pure and applied mathematics.

  16. Dark fermentation on biohydrogen production: Pure culture.

    Science.gov (United States)

    Lee, Duu-Jong; Show, Kuan-Yeow; Su, Ay

    2011-09-01

    Biohydrogen is regarded as an attractive future clean energy carrier due to its high energy content and environmental-friendly conversion. While biohydrogen production is still in the early stage of development, there have been a variety of laboratory- and pilot-scale systems developed with promising potential. This work presents a review of literature reports on the pure hydrogen-producers under anaerobic environment. Challenges and perspective of biohydrogen production with pure cultures are also outlined.

  17. Bimetallic Nickel/Ruthenium Catalysts Synthesized by Atomic Layer Deposition for Low-Temperature Direct Methanol Solid Oxide Fuel Cells.

    Science.gov (United States)

    Jeong, Heonjae; Kim, Jun Woo; Park, Joonsuk; An, Jihwan; Lee, Tonghun; Prinz, Fritz B; Shim, Joon Hyung

    2016-11-09

    Nickel and ruthenium bimetallic catalysts were heterogeneously synthesized via atomic layer deposition (ALD) for use as the anode of direct methanol solid oxide fuel cells (DMSOFCs) operating in a low-temperature range. The presence of highly dispersed ALD Ru islands over a porous Ni mesh was confirmed, and the Ni/ALD Ru anode microstructure was observed. Fuel cell tests were conducted using Ni-only and Ni/ALD Ru anodes with approximately 350 μm thick gadolinium-doped ceria electrolytes and platinum cathodes. The performance of fuel cells was assessed using pure methanol at operating temperatures of 300-400 °C. Micromorphological changes of the anode after cell operation were investigated, and the content of adsorbed carbon on the anode side of the operated samples was measured. The difference in the maximum power density between samples utilizing Ni/ALD Ru and Pt/ALD Ru, the latter being the best catalyst for direct methanol fuel cells, was observed to be less than 7% at 300 °C and 30% at 350 °C. The improved electrochemical activity of the Ni/ALD Ru anode compared to that of the Ni-only anode, along with the reduction of the number of catalytically active sites due to agglomeration of Ni and carbon formation on the Ni surface as compared to Pt, explains this decent performance.

  18. Nano-Engineered Catalysts for Direct Methanol Fuel Cells

    Science.gov (United States)

    Myung, Nosang; Narayanan, Sekharipuram; Wiberg, Dean

    2008-01-01

    Nano-engineered catalysts, and a method of fabricating them, have been developed in a continuing effort to improve the performances of direct methanol fuel cells as candidate power sources to supplant primary and secondary batteries in a variety of portable electronic products. In order to realize the potential for high energy densities (as much as 1.5 W h/g) of direct methanol fuel cells, it will be necessary to optimize the chemical compositions and geometric configurations of catalyst layers and electrode structures. High performance can be achieved when catalyst particles and electrode structures have the necessary small feature sizes (typically of the order of nanometers), large surface areas, optimal metal compositions, high porosity, and hydrophobicity. The present method involves electrodeposition of one or more catalytic metal(s) or a catalytic-metal/polytetrafluoroethylene nanocomposite on an alumina nanotemplate. The alumina nanotemplate is then dissolved, leaving the desired metal or metal/polytetrafluoroethylene-composite catalyst layer. Unlike some prior methods of making fine metal catalysts, this method does not involve processing at elevated temperature; all processing can be done at room temperature. In addition, this method involves fewer steps and is more amenable to scaling up for mass production. Alumina nanotemplates are porous alumina membranes that have been fabricated, variously, by anodizing either pure aluminum or aluminum that has been deposited on silicon by electronbeam evaporation. The diameters of the pores (7 to 300 nm), areal densities of pores (as much as 7 x 10(exp 10)sq cm), and lengths of pores (up to about 100 nm) can be tailored by selection of fabrication conditions. In a given case, the catalytic metal, catalytic metal alloy, or catalytic metal/ polytetrafluoroethylene composite is electrodeposited in the pores of the alumina nanotemplate. The dimensions of the pores, together with the electrodeposition conditions

  19. A Study on the Combustion and Methanol and Formaldehyde Emission Characteristics of Methanol Gasoline Engine%甲醇汽油发动机燃烧及其醇醛排放特性的研究

    Institute of Scientific and Technical Information of China (English)

    姚春德; 曾丽丽; 耿鹏; 李旭聪; 王姝荔

    2014-01-01

    The combustion characteristics, the emissions of methanol and formaldehyde, and the fuel econ-omy are tested of an in-line 4-cylinder port-injection gasoline engine, meeting State-III emission standard, fueled with gasoline, M15 and M50 methanol/gasoline blends respectively with urban road and highway cycles of European test cycles. The results show that with the increase in methanol content, the peak cylinder pressure rises with an earlier relevant crank angle. Compared with pure gasoline, the methanol/gasoline blend has a higher peak heat re-lease rate, a shorter main combustion period and a low cycle variation rate. The emissions of unburnt methanol and formaldehyde rise with the increase in methanol proportion, and they go up first and then fall down when the load in-crease and almost become null after catalyzed by TWC. The equivalent specific fuel consumption of blend fuels is lower than that of gasoline at medium and high load with its maximum reduction amplitude reaching 9 % at high speed high load condition.%在一台排放达到国Ⅲ标准的直列四缸进气道喷射汽油机上,分别燃用汽油、M15、M50甲醇汽油3种燃油,采用欧洲测试循环中的城市道路工况和高速公路工况循环,对3种燃料的燃烧特性、醇醛排放和燃油经济性进行了测试。结果表明:最大爆发压力随着掺醇量的增加而增大,且出现的曲轴转角位置提前。掺醇汽油的最大放热率比纯汽油的高,主燃期缩短,循环变动率降低。未燃甲醇和甲醛排放随掺醇比例的增大而增加,随负荷的增大先增加后降低,经催化转化器催化后排放几乎为零。 M15和M50的当量燃油消耗率在中高负荷下比汽油低,特别在高速大负荷条件下最大降幅达9.0%。

  20. Pure Parsimony Xor Haplotyping

    CERN Document Server

    Bonizzoni, Paola; Dondi, Riccardo; Pirola, Yuri; Rizzi, Romeo

    2010-01-01

    The haplotype resolution from xor-genotype data has been recently formulated as a new model for genetic studies. The xor-genotype data is a cheaply obtainable type of data distinguishing heterozygous from homozygous sites without identifying the homozygous alleles. In this paper we propose a formulation based on a well-known model used in haplotype inference: pure parsimony. We exhibit exact solutions of the problem by providing polynomial time algorithms for some restricted cases and a fixed-parameter algorithm for the general case. These results are based on some interesting combinatorial properties of a graph representation of the solutions. Furthermore, we show that the problem has a polynomial time k-approximation, where k is the maximum number of xor-genotypes containing a given SNP. Finally, we propose a heuristic and produce an experimental analysis showing that it scales to real-world large instances taken from the HapMap project.

  1. Pure parsimony xor haplotyping.

    Science.gov (United States)

    Bonizzoni, Paola; Della Vedova, Gianluca; Dondi, Riccardo; Pirola, Yuri; Rizzi, Romeo

    2010-01-01

    The haplotype resolution from xor-genotype data has been recently formulated as a new model for genetic studies. The xor-genotype data is a cheaply obtainable type of data distinguishing heterozygous from homozygous sites without identifying the homozygous alleles. In this paper, we propose a formulation based on a well-known model used in haplotype inference: pure parsimony. We exhibit exact solutions of the problem by providing polynomial time algorithms for some restricted cases and a fixed-parameter algorithm for the general case. These results are based on some interesting combinatorial properties of a graph representation of the solutions. Furthermore, we show that the problem has a polynomial time k-approximation, where k is the maximum number of xor-genotypes containing a given single nucleotide polymorphisms (SNP). Finally, we propose a heuristic and produce an experimental analysis showing that it scales to real-world large instances taken from the HapMap project.

  2. Improved Flow-Field Structures for Direct Methanol Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Gurau, Bogdan

    2013-05-31

    The direct methanol fuel cell (DMFC) is ideal if high energy-density liquid fuels are required. Liquid fuels have advantages over compressed hydrogen including higher energy density and ease of handling. Although state-of-the-art DMFCs exhibit manageable degradation rates, excessive fuel crossover diminishes system energy and power density. Although use of dilute methanol mitigates crossover, the concomitant lowering of the gross fuel energy density (GFED) demands a complex balance-of-plant (BOP) that includes higher flow rates, external exhaust recirculation, etc. An alternative approach is redesign of the fuel delivery system to accommodate concentrated methanol. NuVant Systems Inc. (NuVant) will maximize the GFED by design and assembly of a DMFC that uses near neat methanol. The approach is to tune the diffusion of highly concentrated methanol (to the anode catalytic layer) to the back-diffusion of water formed at the cathode (i.e. in situ generation of dilute methanol at the anode layer). Crossover will be minimized without compromising the GFED by innovative integration of the anode flow-field and the diffusion layer. The integrated flow-field-diffusion-layers (IFDLs) will widen the current and potential DMFC operating ranges and enable the use of cathodes optimized for hydrogen-air fuel cells.

  3. Effect of Al-Cu Bimetallic Components in a TiO2 Framework for High Hydrogen Production on Methanol/Water Photo-Splitting

    Directory of Open Access Journals (Sweden)

    A-Young Kim

    2012-01-01

    Full Text Available This study investigated the production of hydrogen over TiO2, Cu-TiO2, Ag-TiO2, and Cu-Ag-TiO2 photocatalysts incorporated with Cu and Ag ions by a solvothermal method. The Ag metal (200, 220, and 311 plane peaks at 2=44.50, 64.00, and 77.60o were presented in the Ag-incorporated TiO2 catalysts. The CuO component (Cu2p3/2 and Cu2p1/2 at 930.4 and 949.5 eV was exhibited in the X-ray photon spectroscopy (XPS band of the Cu-incorporated TiO2 photocatalyst. All the absorption plots in the Cu-, Ag-, and Cu-Ag-incorporated catalysts showed excitation characteristics; an asymmetric tail was observed towards a higher wavelength due to scattering. The intensity of the photoluminescence (PL curves of Cu-Ag-TiO2s was smaller, with the smallest case being observed for Cu(0.05-Ag(0.05Ti(0.9O2 and Cu(0.03-Ag(0.07Ti(0.9O2. Based on these optical characteristics, the production of H2 from methanol/water photodecomposition over the Cu(0.03-Ag(0.07Ti(0.9O2 photocatalyst at 8,750 mmol after 8 h was greater than that over the other photocatalysts.

  4. Scaledown of a methanol reactor

    Energy Technology Data Exchange (ETDEWEB)

    Berty, J.M.

    1983-07-01

    This article shows how it is possible to define operating conditions for pilot plants and development labs by scaling down a commercial reactor. Points out that scaledown consideration and experiment planning can be done in a similar manner for the boiling water-cooled, Lurgi-type reactor. Explains that although the design of large, single-train plants to produce methanol for fuel use has different economic objectives, product specifications, and technical constraints from the traditional commercial methanol plants, the same fundamental laws of thermodynamics and reaction kinetics apply to both types of operation.

  5. High deposition rate a-Si:H layers from pure SiH4 and from a 10% dilution of SiH4 in H2

    OpenAIRE

    1999-01-01

    In this paper, we present results of the deposition rates and the characterization of a-Si:H layers deposited from pure SiH4 in a 13.56 MHz Plasma Enhanced Chemical Vapor Deposition (PECVD) equipment, where the use of parallel plates of equal area, long gas residence as well as the optimization of process parameters permitted to double previously reported deposition rates obtained employing this rf frequency and gas. A deposition process using a 10% dilution of SiH4 in H2.was also optimized t...

  6. Emissions characteristics of a diesel engine operating on biodiesel and biodiesel blended with ethanol and methanol.

    Science.gov (United States)

    Zhu, Lei; Cheung, C S; Zhang, W G; Huang, Zhen

    2010-01-15

    Euro V diesel fuel, pure biodiesel and biodiesel blended with 5%, 10% and 15% of ethanol or methanol were tested on a 4-cylinder naturally-aspirated direct-injection diesel engine. Experiments were conducted under five engine loads at a steady speed of 1800 r/min. The study aims to investigate the effects of the blended fuels on reducing NO(x) and particulate. On the whole, compared with Euro V diesel fuel, the blended fuels could lead to reduction of both NO(x) and PM of a diesel engine, with the biodiesel-methanol blends being more effective than the biodiesel-ethanol blends. The effectiveness of NO(x) and particulate reductions is more effective with increase of alcohol in the blends. With high percentage of alcohol in the blends, the HC, CO emissions could increase and the brake thermal efficiency might be slightly reduced but the use of 5% blends could reduce the HC and CO emissions as well. With the diesel oxidation catalyst (DOC), the HC, CO and particulate emissions can be further reduced.

  7. Copper(II) mediated facile and ultra fast peptide synthesis in methanol.

    Science.gov (United States)

    Mali, Sachitanand M; Jadhav, Sandip V; Gopi, Hosahudya N

    2012-07-18

    A novel, ultrafast, mild and scalable amide bond formation strategy in methanol using simple thioacids and amines is described. The mechanism suggests that the coupling reactions are initially mediated by CuSO(4)·5H(2)O and subsequently catalyzed by in situ generated copper sulfide. The pure peptides were isolated in satisfactory yields in less than 5 minutes.

  8. High-performance liquid chromatographic method for the determination of nicardipine in pure, pharmaceutical preparations and plasma and its application to pharmacokinetics in humans

    Directory of Open Access Journals (Sweden)

    Sheikha M. Al-Ghannam

    2009-01-01

    Full Text Available A simple, sensitive and reproducible reversed-phase liquid chromatographic method has been developed and validated for the determination of nicardipine hydrochloride (NC in pure, pharmaceutical preparations, human plasma and the study of the pharmacokinetics of the drug in human body. Nicardipine in plasma were extracted with hexane-butanol (12:1,v/v after addition of borate buffer (0.5 M, pH=9.0, and then measured by HPLC-UV using a Waters Symmetry C18 column as stationary phase and methanol– triethylamine buffer (0.01M pH 4 with acetic acid (70:30 as mobile phase. Nicardipine was quantified by ultraviolet absorbance at 353 nm. The method proved to be linear in the pure drug in the ranges of 15-200 ng/mL (r=0.9989 and 5-40 ?g/mL (r=0.9995, and for the pharmaceutical preparations and plasma for drug concentrations in the range of 5-40 ?g/mL (r =0.9992 and 25-150 ng/mL (r=0.9991, respectively. The lower limit of detection and the lower quantitation limit of NC in plasma were 11.74 and 35.57 ng/mL, respectively. The method is sensitive and reliable for harmacokineticstudies of nicardipine in humans after the oral administration of immediate-release capsules to healthy subjects.

  9. Behavior of a methanol fuel cell in transitory regime

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, M.F.; Pilla, A.S.; Duarte, M.M.E.; Mayer, C.E. [Instituto de Ingenieria Electroquimica y Corrosion, Depto. de Ingenieria Quimica, Universidad Nacional del Sur, Av. Alem 1253, 8000 Bahia Blanca (Argentina)

    2010-06-15

    The operation of a polymeric electrolyte methanol/air fuel cell connected to a storage tank with anolyte batch recycle is analyzed. When the cell is discharged at constant current, far below the anode reaction limiting current density, the concentration in the tank is found to decrease with time following a lineal variation. At zero time, a high CO{sub 2} concentration is detected in the air leaving the cathode compartment, which increased when higher methanol concentration is used in the anode compartment. This effect is associated to the crossover of methanol through the membrane. The amount of CO{sub 2} in the air outlet is important, and both this quantity and the crossover flux decrease when methanol concentration diminish in the anolyte. A model derived from electrochemical reactor analysis, that correlates methanol concentration changes in the storage tank, and methanol concentration at the anodic compartment exit with the amount consumed in the cell reaction and the flow through the membrane is developed. (author)

  10. Methane and methanol oxidation in supercritical water: Chemical kinetics and hydrothermal flame studies

    Energy Technology Data Exchange (ETDEWEB)

    Steeper, R.R.

    1996-01-01

    Supercritical water oxidation (SCWO) is an emerging technology for the treatment of wastes in the presence of a large concentration of water at conditions above water`s thermodynamic critical point. A high-pressure, optically accessible reaction cell was constructed to investigate the oxidation of methane and methanol in this environment. Experiments were conducted to examine both flame and non-flame oxidation regimes. Optical access enabled the use of normal and shadowgraphy video systems for visualization, and Raman spectroscopy for in situ measurement of species concentrations. Flame experiments were performed by steadily injecting pure oxygen into supercritical mixtures of water and methane or methanol at 270 bar and at temperatures from 390 to 510{degrees}C. The experiments mapped conditions leading to the spontaneous ignition of diffusion flames in supercritical water. Above 470{degrees}C, flames spontaneously ignite in mixtures containing only 6 mole% methane or methanol. This data is relevant to the design and operation of commercial SCWO processes that may be susceptible to inadvertent flame formation. Non-flame oxidation kinetics experiments measured rates of methane oxidation in supercritical water at 270 bar and at temperatures from 390 to 442{degrees}C. The initial methane concentration was nominally 0.15 gmol/L, a level representative of commercial SCWO processes. The observed methane concentration histories were fit to a one-step reaction rate expression indicating a reaction order close to two for methane and zero for oxygen. Experiments were also conducted with varying water concentrations (0 to 8 gmol/L) while temperature and initial reactant concentrations were held constant. The rate of methane oxidation rises steadily with water concentration up to about 5 gmol/L and then abruptly falls off at higher concentrations.

  11. Biodiesel II: A new concept of biodiesel production - transesterification with supercritical methanol

    Directory of Open Access Journals (Sweden)

    Skala Dejan U.

    2004-01-01

    Full Text Available Biodiesel is defined as a fuel that might be used as a pure biofuel or at high concentration in mineral oil derivatives, in accordance with specific quality standards for transport applications. The main raw material used for biodiesel production is rapeseed, which contains mono-unsaturated (about 60% and also, in a lower quantity, poly-unsaturated fatty acids (C 18:1 and C 18:3, as well as some amounts of undesired saturated fatty acids (palmitic and stearic acids. Other raw materials have also been used in the research and industrial production of biodiesel (palm-oil, sunflower-oil, soybean-oil, waste plant oil, animal fats, etc. The historical background of the biodiesel production, installed industrial capacities, as well as Directives of the European Parliament and of the Council (May 2003 regarding the promotion of the use of biofuels or other renewable fuels for transport are discussed in the first part of this article (Chem. Ind. 58 (2004. The second part focused on some new concepts and the future development of technology for biodiesel production based on the use of non-catalytic transesterification under supercritical conditions. A literature review, as well as original results based on the transesterification of animal fats, plant oil and used plant oil were discussed. Obtained results were compared with the traditional concept of transesterification based on base or acid catalysis. Experimental investigations of transesterification with supercritical methanol were performed in a 2 dm3 autoclave at 140 bar pressure and at 300°C with molar ratio of methanol to triglycerides of about 41. The degree of esterification strongly depends on the density of supercritical methanol and on the possibility of reaction occurring in one phase.

  12. Mixtures of methanol and 2-propanol as a potential fuel for direct alcohol fuel cells

    Directory of Open Access Journals (Sweden)

    S. LJ. GOJKOVIC

    2007-12-01

    Full Text Available The electrochemical oxidation of methanol, 2-propanol, and their mixtures was investigated on a Pt/C thin film electrode in acid solution. It was confirmed that the oxidation of 2-propanol commences at less positive potentials than that of methanol and exhibits significantly higher oxidation current densities at low potentials. When both methanol and 2-propanol were present in the solution, the onset of the oxidation current was the same as for the oxidation of pure 2-propanol. Although both alcohols inhibit the oxidation reaction of each other to a certain extent, steady-state polarization measurements showed that their mixture provides higher current densities than single alcohols over the entire potential region from the hydrogen region to oxide formation on the Pt surface. This implies that the addition of 2-propanol into the fuel may extend the operational range of direct methanol fuel cells.

  13. Towards a methanol economy based on homogeneous catalysis: methanol to H2 and CO2 to methanol

    DEFF Research Database (Denmark)

    Alberico, E.; Nielsen, Martin

    2015-01-01

    The possibility to implement both the exhaustive dehydrogenation of aqueous methanol to hydrogen and CO2 and the reverse reaction, the hydrogenation of CO2 to methanol and water, may pave the way to a methanol based economy as part of a promising renewable energy system. Recently, homogeneous...

  14. Metal membrane-type 25-kW methanol fuel processor for fuel-cell hybrid vehicle

    Science.gov (United States)

    Han, Jaesung; Lee, Seok-Min; Chang, Hyuksang

    A 25-kW on-board methanol fuel processor has been developed. It consists of a methanol steam reformer, which converts methanol to hydrogen-rich gas mixture, and two metal membrane modules, which clean-up the gas mixture to high-purity hydrogen. It produces hydrogen at rates up to 25 N m 3/h and the purity of the product hydrogen is over 99.9995% with a CO content of less than 1 ppm. In this fuel processor, the operating condition of the reformer and the metal membrane modules is nearly the same, so that operation is simple and the overall system construction is compact by eliminating the extensive temperature control of the intermediate gas streams. The recovery of hydrogen in the metal membrane units is maintained at 70-75% by the control of the pressure in the system, and the remaining 25-30% hydrogen is recycled to a catalytic combustion zone to supply heat for the methanol steam-reforming reaction. The thermal efficiency of the fuel processor is about 75% and the inlet air pressure is as low as 4 psi. The fuel processor is currently being integrated with 25-kW polymer electrolyte membrane fuel-cell (PEMFC) stack developed by the Hyundai Motor Company. The stack exhibits the same performance as those with pure hydrogen, which proves that the maximum power output as well as the minimum stack degradation is possible with this fuel processor. This fuel-cell 'engine' is to be installed in a hybrid passenger vehicle for road testing.

  15. Insight into the Reaction Mechanisms of Methanol on PtRu/Pt(111): A Density Functional Study

    Science.gov (United States)

    Ding, Qiuyue; Xu, Wenbin; Sang, Pengpeng; Xu, Jing; Zhao, Lianming; He, Xiaoli; Guo, Wenyue

    2016-04-01

    Periodic DFT calculations have been performed to systematically investigate the mechanisms of methanol decomposition and oxidation on the PtRu/Pt(111) surface. Geometries and energies for the primary species involved are analyzed and the reaction network has been mapped out. The calculation shows that among three initial Csbnd H, Osbnd H, and Csbnd O bond scissions of methanol, the Osbnd H bond scission is found to be the most favorable and bears a lower energy barrier than the desorption of methanol. The decomposition of CH3O occurs via the path CH3O → CH2O → CHO → CO with the limiting step of the first dehydrogenation. Although the oxidation of CO is hindered by a high barrier, the CHO oxidation to CHOOH could occur facilely. Further decomposition of formic acid to CO2 and/or CO could occur via four possible pathways, that is, initial Csbnd H, Osbnd H, and Csbnd O bond activations as well as simultaneous activation of Csbnd H and Csbnd O bonds, where the first pathway, HCOOH → COOH → CO2, is the most favorable from a kinetic point of view. Compared to that on Pt(111), methanol on PtRu/Pt(111) prefers to decomposition rather than desorption and then oxidation via the favorable non-CO path with a lower rate-determining energy barrier of CH3O → CH2O for the whole reaction, which indicates that PtRu alloy can improved tolerance toward CO poisoning compared with pure Pt.

  16. Prediction and validation of hemodialysis duration in acute methanol poisoning.

    Science.gov (United States)

    Lachance, Philippe; Mac-Way, Fabrice; Desmeules, Simon; De Serres, Sacha A; Julien, Anne-Sophie; Douville, Pierre; Ghannoum, Marc; Agharazii, Mohsen

    2015-11-01

    The duration of hemodialysis (HD) in methanol poisoning (MP) is dependent on the methanol concentration, the operational parameters used during HD, and the presence and severity of metabolic acidosis. However, methanol assays are not easily available, potentially leading to undue extension or premature termination of treatment. Here we provide a prediction model for the duration of high-efficiency HD in MP. In a retrospective cohort study, we identified 71 episodes of MP in 55 individuals who were treated with alcohol dehydrogenase inhibition and HD. Four patients had residual visual abnormality at discharge and only one patient died. In 46 unique episodes of MP with high-efficiency HD the mean methanol elimination half-life (T1/2) during HD was 108 min in women, significantly different from the 129 min in men. In a training set of 28 patients with MP, using the 90th percentile of gender-specific elimination T1/2 (147 min in men and 141 min in women) and a target methanol concentration of 4 mmol/l allowed all cases to reach a safe methanol of under 6 mmol/l. The prediction model was confirmed in a validation set of 18 patients with MP. High-efficiency HD time in hours can be estimated using 3.390 × (Ln (MCi/4)) for women and 3.534 × (Ln (MCi/4)) for men, where MCi is the initial methanol concentration in mmol/l, provided that metabolic acidosis is corrected.

  17. Electroretinogram and Histopathologic Changes of the Retina after Methanol Intoxication

    Institute of Scientific and Technical Information of China (English)

    CHEN Jie-min; ZHU Guang-you; ZHAO Zi-qin; XIA Wen-tao

    2013-01-01

    In order to study the functional and structural alterations of the retina in SD rat model after methanol intoxication,35 rats were divided randomly into five groups administrated with saline,3-day high dose,7-day high dose,3-day low dose and 7-day low dose methanol separately.The retinal function of each group was assessed by flash electroretinogram (F-ERG) 3 and 7 days after methanol poisoning.The microstructure and ultrastructure of the retina were observed at the same time.The high-dose methanol intoxication induced irreversible retinal functional and structural damages 3 days after poisoning,which included prolonged latency and reduced amplitude of the Max-reaction of F-ERG.These injuries were aggravated 7 days after poisoning.Meanwhile,the latency and amplitude of the Cone-reaction of F-ERG were also affected 3 days after poisoning,but there were no further worsening tendency 7 days after poisoning.The retinal histological analysis showed cellular edema,heteromorphy and disarrangement,tissular loosen of the inner nuclear layer and photoreceptors layer.The mitochondrial damage began at the photoreceptors layer and developed further into the inner nuclear layer.The low-dose methanol intoxication only caused transient damage of the retina.Our results showed that the function and structure of the photoreceptor and inner nuclear layer were the primary target of methanol intoxication and that the rod cells were more sensitive to methanol intoxication than the cone cells.The mitochondrial damage developed from outer layer to inner layer of the retina.

  18. Enhanced methanol utilization in direct methanol fuel cell

    Science.gov (United States)

    Ren, Xiaoming; Gottesfeld, Shimshon

    2001-10-02

    The fuel utilization of a direct methanol fuel cell is enhanced for improved cell efficiency. Distribution plates at the anode and cathode of the fuel cell are configured to distribute reactants vertically and laterally uniformly over a catalyzed membrane surface of the fuel cell. A conductive sheet between the anode distribution plate and the anodic membrane surface forms a mass transport barrier to the methanol fuel that is large relative to a mass transport barrier for a gaseous hydrogen fuel cell. In a preferred embodiment, the distribution plate is a perforated corrugated sheet. The mass transport barrier may be conveniently increased by increasing the thickness of an anode conductive sheet adjacent the membrane surface of the fuel cell.

  19. Fermentation of methanol in the sheep rumen.

    OpenAIRE

    Pol, A.; Demeyer, D. I.

    1988-01-01

    Sheep fed a hay-concentrate diet were adapted to pectin administration and ruminal infusion of methanol. Both treatments resulted in a strong increase in the rate of methanogenesis from methanol. Quantitative data show that methanol was exclusively converted into methane. Treatments did not influence ruminal volatile fatty acid percentages.

  20. The fate of methanol in anaerobic bioreactors

    NARCIS (Netherlands)

    Florencio, L.

    1994-01-01

    Methanol is an important component of certain industrial wastewaters. In anaerobic environments, methanol can be utilized by methanogens and acetogens. In wastewater treatment plants, the conversion of methanol into methane is preferred because this conversion is responsible for chemical

  1. The fate of methanol in anaerobic bioreactors.

    NARCIS (Netherlands)

    Florencio, L.

    1994-01-01

    Methanol is an important component of certain industrial wastewaters. In anaerobic environments, methanol can be utilized by methanogens and acetogens. In wastewater treatment plants, the conversion of methanol into methane is preferred because this conversion is responsible for chemical oxygen dema

  2. Evidence for an initiation of the methanol-to-olefin process by reactive surface methoxy groups on acidic zeolite catalysts.

    Science.gov (United States)

    Wang, Wei; Buchholz, Andreas; Seiler, Michael; Hunger, Michael

    2003-12-10

    Recent progress reveals that, in the methanol-to-olefin (MTO) process on acidic zeolites, the conversion of an equilibrium mixture of methanol and DME is dominated by a "hydrocarbon pool" mechanism. However, the initial C-C bond formation, that is, the chemistry during the kinetic "induction period" leading to the reactive hydrocarbon pool, still remains unclear. With the application of a stopped-flow protocol, in the present work, pure surface methoxy groups [SiO(CH(3))Al] were prepared on various acidic zeolite catalysts (H-Y, H-ZSM-5, H-SAPO-34) at temperatures lower than 473 K, and the further reaction of these methoxy species was investigated by in situ (13)C MAS NMR spectroscopy. By using toluene and cyclohexane as probe molecules which are possibly involved in the MTO process, we show the high reactivity of surface methoxy species. Most importantly, the formation of hydrocarbons from pure methoxy species alone is demonstrated for the first time. It was found that (i) surface methoxy species react at room temperature with water to methanol, indicating the occurrence of a chemical equilibrium between these species at low temperatures. In the presence of aromatics and alkanes, (ii) the reactivity of surface methoxy groups allows a methylation of these organic compounds at reaction temperatures of ca. 433 and 493 K, respectively. In the absence of water and other organic species, that is, under flow conditions and on partially methylated catalysts, (iii) a conversion of pure methoxy groups alone to hydrocarbons was observed at temperatures of T >/= 523 K. This finding indicates a possible formation of the first hydrocarbons during the kinetic induction period of the MTO process via the conversion of pure surface methoxy species (case iii). After the first hydrocarbons are formed, or in the presence of a small amount of organic impurities, surface methoxy groups contribute to a further methylation of these organic compounds (case ii), leading to the formation of

  3. Catalytic gasification of bagasse for the production of methanol

    Energy Technology Data Exchange (ETDEWEB)

    Baker, E.G.; Brown, M.D.; Robertus, R.J.

    1985-10-01

    The purpose of the study was to evaluate the technical and economic feasibility of catalytic gasification of bagasse to produce methanol. In previous studies, a catalytic steam gasification process was developed which converted wood to methanol synthesis gas in one step using nickel based catalysts in a fluid-bed gasifier. Tests in a nominal 1 ton/day process development unit (PDU) gasifier with these same catalysts showed bagasse to be a good feedstock for fluid-bed gasifiers, but the catalysts deactivated quite rapidly in the presence of bagasse. Laboratory catalyst screening tests showed K/sub 2/CO/sub 3/ doped on the bagasse to be a promising catalyst for converting bagasse to methanol synthesis gas. PDU tests with 10 wt % K/sub 2/CO/sub 3/ doped on bagasse showed the technical feasibility of this type of catalyst on a larger scale. A high quality synthesis gas was produced and carbon conversion to gas was high. The gasifier was successfully operated without forming agglomerates of catalyst, ash, and char in the gasifier. There was no loss of activity throughout the runs because catalysts is continually added with the bagasse. Laboratory tests showed about 80% of the potassium carbonate could be recovered and recycled with a simple water wash. An economic evaluation of the process for converting bagasse to methanol showed the required selling price of methanol to be significantly higher than the current market price of methanol. Several factors make this current evaluaton using bagasse as a feedstock less favorable: (1) capital costs are higher due to inflation and some extra costs required to use bagasse, (2) smaller plant sizes were considered so economies of scale are lost, and (3) the market price of methanol in the US has fallen 44% in the last six months. 24 refs., 14 figs., 16 tabs.

  4. Nokia PureView oversampling technology

    Science.gov (United States)

    Vuori, Tero; Alakarhu, Juha; Salmelin, Eero; Partinen, Ari

    2013-03-01

    This paper describes Nokia's PureView oversampling imaging technology as well as the product, Nokia 808 PureView, featuring it. The Nokia PureView imaging technology is the combination of a large, super high resolution 41Mpix with high performance Carl Zeiss optics. Large sensor enables a pixel oversampling technique that reduces an image taken at full resolution into a lower resolution picture, thus achieving higher definition and light sensitivity. One oversampled super pixel in image file is formed by using many sensor pixels. A large sensor enables also a lossless zoom. If a user wants to use the lossless zoom, the sensor image is cropped. However, up-scaling is not needed as in traditional digital zooming usually used in mobile devices. Lossless zooming means image quality that does not have the digital zooming artifacts as well as no optical zooming artifacts like zoom lens system distortions. Zooming with PureView is also completely silent. PureView imaging technology is the result of many years of research and development and the tangible fruits of this work are exceptional image quality, lossless zoom, and superior low light performance.

  5. Withanolide artifacts formed in methanol.

    Science.gov (United States)

    Cao, Cong-Mei; Zhang, Huaping; Gallagher, Robert J; Timmermann, Barbara N

    2013-11-22

    Methanol solutions of the main withanolides (6-8) naturally present in Physalis longifolia yielded five artificial withanolides (1-5), including three new compounds (1-3). Withanolides 1 and 2 were identified as intramolecular Michael addition derivatives, while withanolides 3-5 were the result of intermolecular Michael addition. A comprehensive literature investigation was conducted to identify potential withanolide Michael addition artifacts isolated from Solanaceous species to date.

  6. An electrode with Ni(II) loaded analcime zeolite catalyst for the electrooxidation of methanol

    Institute of Scientific and Technical Information of China (English)

    Seyed Naser Azizi; Shahram Ghasemi; Neda Salek Gilani

    2014-01-01

    There is a high overvoltage in the oxidation of methanol in fuel cells, and so modified electrodes are used to decrease it. A modified electrode that used Ni(II) loaded analcime zeolite to catalyze the electrooxidation of methanol in alkaline solution was proposed. Analcime zeolite was synthesized by hydrothermal synthesis, and Ni(II) ions were incorporated into the analcime structure, which was then mixed with carbon paste to prepare modified electrode. The electrocatalytic oxidation of methanol on the surface of the modified electrode in alkaline solution was investigated by cyclic voltammetry and chronoamperometry. The effects of the scan rate of the potential, concentration of methanol, and amount of zeolite were investigated. The rate constant for the catalytic reaction of methanol was 6 × 103 cm3 mol-1 s-1 from measurements using chronoamperometry. The proposed electrode significantly improved the electron transfer rate and decreased the overpotential for methanol oxidation.

  7. Pulse shape discrimination characteristics of stilbene crystal, pure and 6Li loaded plastic scintillators for a high resolution coded-aperture neutron imager

    Science.gov (United States)

    Cieślak, M. J.; Gamage, K. A. A.; Glover, R.

    2017-07-01

    Pulse shape discrimination performances of single stilbene crystal, pure plastic and 6Li loaded plastic scintillators have been compared. Three pulse shape discrimination algorithms have been tested for each scintillator sample, assessing their quality of neutron/gamma separation. Additionally, the digital implementation feasibility of each algorithm in a real-time embedded system was evaluated. Considering the pixelated architecture of the coded-aperture imaging system, a reliable method of simultaneous multi-channel neutron/gamma discrimination was sought, accounting for the short data analysis window available for each individual channel. In this study, each scintillator sample was irradiated with a 252Cf neutron source and a bespoke digitiser system was used to collect the data allowing detailed offline examination of the sampled pulses. The figure-of-merit was utilised to compare the discrimination quality of the collected events with respect to various discrimination algorithms. Single stilbene crystal presents superior neutron/gamma separation performance when compared to the plastic scintillator samples.

  8. The diversity of methanol maser morphologies from VLBI observations

    CERN Document Server

    Bartkiewicz, A; Van Langevelde, H J; Richards, A M S; Pihlström, Y M

    2009-01-01

    We investigate which structures the 6.7 GHz methanol masers trace in the environment of high-mass protostar candidates by observing a homogenous sample of methanol masers selected from Torun surveys. We also probed their origins by looking for associated H II regions and IR emission. We selected 30 methanol sources with improved position accuracies achieved using MERLIN and another 3 from the literature. We imaged 31 of these using the European VLBI Network's expanded array of telescopes with 5-cm (6-GHz) receivers. We used the VLA to search for 8.4 GHz radio continuum counterparts and inspected Spitzer GLIMPSE data at 3.6-8 um from the archive. High angular resolution images allowed us to analyze the morphology and kinematics of the methanol masers in great detail and verify their association with radio continuum and mid-infrared emission. A new class of "ring-like" methanol masers in star--forming regions appeared to be suprisingly common, 29 % of the sample. The new morphology strongly suggests that methan...

  9. The toxicity of inhaled methanol vapors

    Energy Technology Data Exchange (ETDEWEB)

    Kavet, R.; Nauss, K.M. (Environmental Research Information, Inc., Palo Alto, CA (USA))

    1990-01-01

    Methanol could become a major automotive fuel in the U.S., and its use may result in increased exposure of the public to methanol vapor. Nearly all of the available information on methanol toxicity in humans relates to the consequences of acute, rather than chronic, exposures. Acute methanol toxicity evolves in a well-understood pattern and consists of an uncompensated metabolic acidosis with superimposed toxicity to the visual system. The toxic properties of methanol are rooted in the factors that govern both the conversion of methanol to formic acid and the subsequent metabolism of formate to carbon dioxide in the folate pathway. In short, the toxic syndrome sets in if formate generation continues at a rate that exceeds its rate of metabolism. Current evidence indicates that formate accumulation will not challenge the metabolic capacity of the folate pathway at the anticipated levels of exposure to automotive methanol vapor.117 references.

  10. 剧烈塑性变形制备高强度高导电纯铜的研究%Investigation of High Tensile Strength and High Electrical Conductivity Pure Copper Fabricated by Severe Plastic Deformation

    Institute of Scientific and Technical Information of China (English)

    石凤健; 王雷刚

    2012-01-01

    Microstructure, mechanical property and electrical conductivity of pure copper fabricated by CCDC were investigated. The results show that large strain can be accumulated without changing the shape and dimension of the sample by CCDC, which leads to the grain refinement. The grain size is refined to submicrometer level after 15 passes CCDC through route B. The hardness and tensile strength improve obviously with increasing the number of CCDC. The tensile strength of the copper reaches to 459. IMPa. The elongation to failure of the material decreases, while it is still above 20%. The electrical conductivity decreases with increasing the CCDC number. But the electrical conductivity retains 91. 7%IACS after 15 passes CCDC. The results indicate that bulk pure copper with high strength and excellent electrical conductivity can be fabricated by SPD process of CCDC.%研究了纯铜多道次反复镦压剧烈塑性变形后的组织、力学性能及导电性能.结果表明,通过反复镦压能在保持试样原始形状和尺寸的情况下在材料内部累积很大的应变,实现材料组织的超细化,退火纯铜经B路线15道次反复镦压变形后,晶粒细化至亚微米级.随镦压次数的增加,纯铜的硬度和抗拉强度明显提高,抗拉强度达到459.1MPa,伸长率明显下降,但仍在20%以上.纯铜的导电率随镦压次数的增加而下降,但15道次镦压后仍然保持在91.7%IACS,说明反复镦压剧烈塑性变形工艺可以制备出具有高强度和良好导电性的块体纯铜材料.

  11. EVALUATION OF A PROCESS TO CONVERT BIOMASS TO METHANOL FUEL

    Science.gov (United States)

    The report gives results of a review of the design of a reactor capable of gasifying approximately 50 lb/hr of biomass for a pilot-scale facility to develop, demonstrate, and evaluate the Hynol Process, a high-temperature, high-pressure method for converting biomass into methanol...

  12. A Rare Cause of Metabolic Acidosis: Fatal Transdermal Methanol Intoxication in an Infant.

    Science.gov (United States)

    Sahbudak Bal, Zumrut; Can, Fulya Kamit; Anil, Ayse Berna; Bal, Alkan; Anil, Murat; Gokalp, Gamze; Yavascan, Onder; Aksu, Nejat

    2016-08-01

    Oral methanol intoxication is common, but dermal intoxication is rare. We report a previously healthy 19-month-old female infant admitted to the emergency department (ED) with vomiting and tonic-clonic seizure. On physical examination, she was comatose and presented signs of decompensated shock with Kussmaul breathing. Her left thigh was edematous, with purple coloration. Methanol intoxication was suspected due to high anion gap metabolic acidosis (pH, 6.89; HCO3, acidosis. This case report demonstrates that fatal transdermal methanol intoxication can occur in children, and it is the second report in the English literature of transdermal methanol intoxication in an infant.

  13. Co-consumption of methanol and succinate by Methylobacterium extorquens AM1.

    Directory of Open Access Journals (Sweden)

    Rémi Peyraud

    Full Text Available Methylobacterium extorquens AM1 is a facultative methylotrophic Alphaproteobacterium and has been subject to intense study under pure methylotrophic as well as pure heterotrophic growth conditions in the past. Here, we investigated the metabolism of M. extorquens AM1 under mixed substrate conditions, i.e., in the presence of methanol plus succinate. We found that both substrates were co-consumed, and the carbon conversion was two-thirds from succinate and one-third from methanol relative to mol carbon. (13C-methanol labeling and liquid chromatography mass spectrometry analyses revealed the different fates of the carbon from the two substrates. Methanol was primarily oxidized to CO(2 for energy generation. However, a portion of the methanol entered biosynthetic reactions via reactions specific to the one-carbon carrier tetrahydrofolate. In contrast, succinate was primarily used to provide precursor metabolites for bulk biomass production. This work opens new perspectives on the role of methylotrophy when substrates are simultaneously available, a situation prevailing under environmental conditions.

  14. Thermodynamic Properties of the Azeotropic Mixture of Acetone, Cyclohexane and Methanol

    Institute of Scientific and Technical Information of China (English)

    WANG Xiu-Rong; NAN Zhao-Dong; TAN Zhi-Cheng

    2006-01-01

    Molar heat capacities of the pure samples of acetone, methanol and the azeotropic mixture composed of acetone,cyclohexane and methanol were measured by an adiabatic calorimeter from 78 to 320 K. The solid-solid and solid-liquid phase transitions of the pure samples and the mixture were determined based on the curve of the heat capacity with respect to temperature. The phase transitions took place at (126.16±0.68) and (178.96±1.47) K for the sample of acetone, (157.79±0.95) and (175.93±0.95) K for methanol, which were corresponding to the solid-solid and the solid-liquid phase transitions of the acetone and the methanol, respectively. And the phase transitions occurred in the temperature ranges of 120 to 190 K and 278 to 280 K corresponding to the solid-solid and the solid-liquid phase transitions of mixture of acetone, cyclohexane and methanol, respectively. The thermodynamic functions and the excess thermodynamic functions of the mixture relative to standard temperature of 298.15 K were derived based on the relationships of the thermodynamic functions and the function of the measured heat capacity with respect to temperature.

  15. Deuterated methanol in Orion BN/KL

    CERN Document Server

    Peng, T -C; Brouillet, N; Parise, B; Baudry, A

    2012-01-01

    Deuterated molecules have been detected and studied toward Orion BN/KL in the past decades, mostly with single-dish telescopes. However, high angular resolution data are critical not only for interpreting the spatial distribution of the deuteration ratio but also for understanding this complex region in terms of cloud evolution involving star-forming activities and stellar feedbacks. We present here the first high angular resolution (1.8 arcsec \\times 0.8 arcsec) images of deuterated methanol CH2DOH in Orion BN/KL observed with the IRAM Plateau de Bure Interferometer from 1999 to 2007 in the 1 to 3 mm range. Six CH2DOH lines were detected around 105.8, 223.5, and 225.9 GHz. In addition, three E-type methanol lines around 101-102 GHz were detected and were used to derive the corresponding CH3OH rotational temperatures and column densities toward different regions across Orion BN/KL. The strongest CH2DOH and CH3OH emissions come from the Hot Core southwest region with an LSR velocity of about 8 km/s. We derive ...

  16. Structural anatomy of pure and hemianopic alexia.

    Science.gov (United States)

    Leff, A P; Spitsyna, G; Plant, G T; Wise, R J S

    2006-09-01

    The two most common types of acquired reading disorder resulting from damage to the territory of the dominant posterior cerebral artery are hemianopic and pure alexia. Patients with pronounced hemianopic alexia have a right homonymous hemianopia that encroaches into central or parafoveal vision; they read individual words well, but generate inefficient reading saccades when reading along a line of text. Patients with pure alexia also often have a hemianopia but are more disabled, making frequent errors on individual words; they have sustained damage to a brain region that supports efficient word identification. To investigate the differences in lesion site between hemianopic alexia and pure alexia groups, as rehabilitative techniques differ between the two conditions. High-resolution magnetic resonance images were obtained from seven patients with hemianopic alexia and from six patients with pure alexia caused by a left occipital stroke. The boundary of each lesion was defined and lesion volumes were then transformed into a standard stereotactic space so that regional comparisons could be made. The two patient groups did not differ in terms of damage to the medial left occipital lobe, but those with pure alexia had additional lateral damage to the posterior fusiform gyrus and adjacent tissue. Clinicians will be able to predict the type of reading disorder patients with left occipital lesions have from simple tests of reading speed and the distribution of damage to the left occipital lobe on brain imaging. This information will aid management decisions, including recommendations for reading rehabilitation.

  17. Retention of ionisable compounds on high-performance liquid chromatography XVII. Estimation of the pH variation of aqueous buffers with the change of the methanol fraction of the mobile phase.

    Science.gov (United States)

    Subirats, Xavier; Bosch, Elisabeth; Rosés, Martí

    2007-01-05

    The use of methanol-aqueous buffer mobile phases in HPLC is a common election when performing chromatographic separations of ionisable analytes. The addition of methanol to the aqueous buffer to prepare such a mobile phase changes the buffer capacity and the pH of the solution. In the present work, the variation of these buffer properties is studied for acetic acid-acetate, phosphoric acid-dihydrogenphosphate-hydrogenphosphate, citric acid-dihydrogencitrate-hydrogencitrate-citrate, and ammonium-ammonia buffers. It is well established that the pH change of the buffers depends on the initial concentration and aqueous pH of the buffer, on the percentage of methanol added, and on the particular buffer used. The proposed equations allow the pH estimation of methanol-water buffered mobile phases up to 80% in volume of organic modifier from initial aqueous buffer pH and buffer concentration (before adding methanol) between 0.001 and 0.01 mol L(-1). From both the estimated pH values of the mobile phase and the estimated pKa of the ionisable analytes, it is possible to predict the degree of ionisation of the analytes and therefore, the interpretation of acid-base analytes behaviour in a particular methanol-water buffered mobile phase.

  18. Experimental investigation of Methanol blends with gasoline on SI engine

    Directory of Open Access Journals (Sweden)

    Gaurav tiwari

    2014-10-01

    Full Text Available Automobile have become a very important part of our modern life style. And it runs on fossil fuel. But the excessive use of fossil fuels will very soon leads to the energy crises so the future of automobile based on fossil fuels has been badly affected by two major problems. That is less availability of fuel and environmental degradation. So it is very important to found some new renewable non polluting alternative fuels to ensure the proper and safe survival of internal combustion engines. In present study we evaluate the performance of two stroke single cylinder spark ignition engine with ratio of 10%, 20% and 30% of methanol and gasoline by volume. Performance parameters (brake thermal efficiency, brake specific energy consumption and brake specific fuel consumption were determined at various loads on engine with methanol blended gasoline. The comparison was made on performance of conventional SI engine with pure gasoline operation. As a result, brake thermal efficiency and brake specific fuel consumption showed improved performance when compared with pure gasoline performances.

  19. Mesoporous Ti(0.5)Cr(0.5)N supported PdAg nanoalloy as highly active and stable catalysts for the electro-oxidation of formic acid and methanol.

    Science.gov (United States)

    Cui, Zhiming; Yang, Minghui; DiSalvo, Francis J

    2014-06-24

    We report a robust noncarbon Ti0.5Cr0.5N support synthesized by an efficient solid-solid phase separation method. This ternary nitride exhibits highly porous, sintered, and random network structure with a crystallite size of 20-40 nm, resulting in a high specific surface area. It is not only kinetically stable in both acid and alkaline media, but also electrochemically stable in the potential range of fuel cell operation. Two typical anode reactions, formic acid oxidation in acid media and methanol oxidation in alkaline media, are employed to investigate the possibility of Ti0.5Cr0.5N as an alternative to carbon. Bimetallic PdAg nanoparticles (∼4 nm) act as anode catalysts for the two anode reactions. PdAg/Ti0.5Cr0.5N exhibits much higher mass activity and durability for the two reactions than PdAg/C and Pd/C catalyst, suggesting that mesoporous Ti0.5Cr0.5N is a very promising support in both acid and alkaline media.

  20. High-level direct-dynamics variational transition state theory calculations including multidimensional tunneling of the thermal rate constants, branching ratios, and kinetic isotope effects of the hydrogen abstraction reactions from methanol by atomic hydrogen.

    Science.gov (United States)

    Meana-Pañeda, Rubén; Truhlar, Donald G; Fernández-Ramos, Antonio

    2011-03-07

    We report a detailed theoretical study of the hydrogen abstraction reaction from methanol by atomic hydrogen. The study includes the analysis of thermal rate constants, branching ratios, and kinetic isotope effects. Specifically, we have performed high-level computations at the MC3BB level together with direct dynamics calculations by canonical variational transition state theory (CVT) with the microcanonically optimized multidimensional tunneling (μOMT) transmission coefficient (CVT/μOMT) to study both the CH(3)OH+H→CH(2)OH+H(2) (R1) reaction and the CH(3)OH+H→CH(3)O+H(2) (R2) reaction. The CVT/μOMT calculations show that reaction R1 dominates in the whole range 298≤T (K)≤2500 and that anharmonic effects on the torsional mode about the C-O bond are important, mainly at high temperatures. The activation energy for the total reaction sum of R1 and R2 reactions changes substantially with temperature and, therefore, the use of straight-line Arrhenius plots is not valid. We recommend the use of new expressions for the total R1 + R2 reaction and for the R1 and R2 individual reactions.

  1. Methanol adsorption studies of electrified ACF by MD simulations

    Institute of Scientific and Technical Information of China (English)

    LIANG Shiqiang; XU Jingzhong

    2004-01-01

    In order to clarify whether static electricity can impose a control on physical adsorption of polar adsorbates, MD simulations were carried out to study the adsorption/desorption behavior of methanol in the nanopores of electrified activated carbon fiber (ACF). Some special phenomena were observed from the MD simulations for methanol adsorption in a mesopore of electrified ACF. For example it takes a shorter time for the adsorbates to reach the adsorption sites on the mesopore wall, the liquid-like methanol is highly condensed, the methanol molecules have a unique distribution of space orientation, and the total energy of equilibrium state dropped a lot. These phenomena indicate the static electricity reinforced the interaction between the polar methanol and the electrified ACF, so that the intensity, stability and regularity of adsorption were increased, and thus we predict that the adsorption capacity will be increased and the adsorption process will be accelerated. When adsorption equilibrium was reached at room temperature, eliminated the electric charges and heated the system, the desorption tendency was evidently observed from our simulations at 60℃ or so.

  2. An autopsy case of methanol induced intracranial hemorrhage.

    Science.gov (United States)

    Kim, Hye-Jeong; Na, Joo-Young; Lee, Young-Jik; Park, Jong-Tae; Kim, Hyung-Seok

    2015-01-01

    The major component of car washer fluid is a methanol. Intracranial hemorrhage is a rare but lethal complication in methanol poisoning. We report a case of massive bilateral basal ganglia hematoma in a 32-year-old man with methanol poisoning. He drank car washer solution twice time (about 500 ml), and was admitted to a territorial hospital 10 hours post-ingestion for depressed mental status, lower blood pressure, and high anion gap metabolic acidosis. Computed tomographic (CT) scan showed lesions in both putamen and cerebral deep white matter. Twenty-one days after methanol exposure, he suddenly developed cardiorespiratory arrest. In autopsy, external examination revealed moderate cerebral edema, but no evidence of herniation. Coronal sections of the brain showed softening and about 34 g hematoma in the bilateral putamen and 3rd ventricles. The toxic effect of methanol on the visual system has been noted in the absence of neurologic manifestations; however, there have also been a report of concomitant brain in Korea.

  3. Observations of the Zeeman effect in Class I methanol masers

    Science.gov (United States)

    Pratim Sarma, Anuj; Momjian, Emmanuel

    2017-01-01

    We present observations of the Zeeman effect in Class I methanol maser sources toward high mass star forming regions. Toward DR21(OH), we have detected the Zeeman effect at 44 GHz in a 219 Jy/beam maser centered at an LSR velocity of 0.83 km/s, and we find $zB_\\text{los} = 53.5 \\pm 2.7$ Hz. If 44 GHz methanol masers are excited at $10^{7-8}$ cm$^{-3}$, then magnetic fields in DR21(OH) should be ~10 mG. Our detected $zB_\\text{los}$ would then imply that the Zeeman splitting factor for the 44 GHz methanol maser line should be ~5 Hz/mG. Such small values for z would not be surprising, since the methanol molecule is non-paramagnetic, like H2O. Since there are no direct measurements or calculations of the 44 GHz methanol maser Zeeman splitting factor to date, such empirical attempts could prove valuable in building a repository of measurements from which to gain an understanding of the magnitude of z.

  4. Pure neuritic leprosy: Current status and relevance

    Directory of Open Access Journals (Sweden)

    P Narasimha Rao

    2016-01-01

    Full Text Available Pure neuritic leprosy has always been an enigma due to its clinical and management ambiguities. Although only the Indian Association of Leprologist's classification recognizes 'pure neuritic leprosy' as a distinct sub group of leprosy, cases nonetheless are reported from various countries of Asia, Africa, South America and Europe, indicating its global relevance. It is important to maintain pure neuritic leprosy as a subgroup as it constitutes a good percentage of leprosy cases reported from India, which contributes to more than half of global leprosy numbers. Unfortunately, a high proportion of these patients present with Grade 2 disability at the time of initial reporting itself due to the early nerve involvement. Although skin lesions are absent by definition, when skin biopsies were performed from the skin along the distribution of the affected nerve, a proportion of patients demonstrated leprosy pathology, revealing sub-clinical skin involvement. In addition on follow-up, skin lesions are noted to develop in up to 20% of pure neuritic leprosy cases, indicating its progression to manifest cutaneous disease. Over the decades, the confirmation of diagnosis of pure neuritic leprosy has been subjective, however, with the arrival and use of high-resolution ultrasonography (HRUS for nerve imaging, we have a tool not only to objectively measure and record the nerve thickening but also to assess the morphological alterations in the nerve including echo texture, fascicular pattern and vascularity. Management of pure neuritic leprosy requires multidrug therapy along with appropriate dose of systemic corticosteroids, for both acute and silent neuritis. Measures for pain relief, self-care of limbs and physiotherapy are important to prevent as well as manage disabilities in this group of patients.

  5. Pure neuritic leprosy: Current status and relevance.

    Science.gov (United States)

    Rao, P Narasimha; Suneetha, Sujai

    2016-01-01

    Pure neuritic leprosy has always been an enigma due to its clinical and management ambiguities. Although only the Indian Association of Leprologist's classification recognizes 'pure neuritic leprosy' as a distinct sub group of leprosy, cases nonetheless are reported from various countries of Asia, Africa, South America and Europe, indicating its global relevance. It is important to maintain pure neuritic leprosy as a subgroup as it constitutes a good percentage of leprosy cases reported from India, which contributes to more than half of global leprosy numbers. Unfortunately, a high proportion of these patients present with Grade 2 disability at the time of initial reporting itself due to the early nerve involvement. Although skin lesions are absent by definition, when skin biopsies were performed from the skin along the distribution of the affected nerve, a proportion of patients demonstrated leprosy pathology, revealing sub-clinical skin involvement. In addition on follow-up, skin lesions are noted to develop in up to 20% of pure neuritic leprosy cases, indicating its progression to manifest cutaneous disease. Over the decades, the confirmation of diagnosis of pure neuritic leprosy has been subjective, however, with the arrival and use of high-resolution ultrasonography (HRUS) for nerve imaging, we have a tool not only to objectively measure and record the nerve thickening but also to assess the morphological alterations in the nerve including echo texture, fascicular pattern and vascularity. Management of pure neuritic leprosy requires multidrug therapy along with appropriate dose of systemic corticosteroids, for both acute and silent neuritis. Measures for pain relief, self-care of limbs and physiotherapy are important to prevent as well as manage disabilities in this group of patients.

  6. Dual Target Search is Neither Purely Simultaneous nor Purely Successive.

    Science.gov (United States)

    Cave, Kyle R; Menneer, Tamaryn; Nomani, Mohammad S; Stroud, Michael J; Donnelly, Nick

    2017-08-31

    Previous research shows that visual search for two different targets is less efficient than search for a single target. Stroud, Menneer, Cave and Donnelly (2012) concluded that two target colours are represented separately based on modeling the fixation patterns. Although those analyses provide evidence for two separate target representations, they do not show whether participants search simultaneously for both targets, or first search for one target and then the other. Some studies suggest that multiple target representations are simultaneously active, while others indicate that search can be voluntarily simultaneous, or switching, or a mixture of both. Stroud et al.'s participants were not explicitly instructed to use any particular strategy. These data were revisited to determine which strategy was employed. Each fixated item was categorised according to whether its colour was more similar to one target or the other. Once an item similar to one target is fixated, the next fixated item is more likely to be similar to that target than the other, showing that at a given moment during search, one target is generally favoured. However, the search for one target is not completed before search for the other begins. Instead, there are often short runs of one or two fixations to distractors similar to one target, with each run followed by a switch to the other target. Thus, the results suggest that one target is more highly weighted than the other at any given time, but not to the extent that search is purely successive.

  7. Mm/submm Study of Gas-Phase Photoproducts from Methanol Interstellar Ice Analogues

    Science.gov (United States)

    Mesko, AJ; Smith, Houston Hartwell; Milam, Stefanie N.; Widicus Weaver, Susanna L.

    2016-06-01

    Icy grain reactions have gained quite the popularity in the astrochemistry community to explain the formation of complex organic molecules. Through temperature programmed desorption and photolysis experiments we use rotational spectroscopy to measure the gas-phase products of icy grain reactions. Previous results include testing detection limits of the system by temperature programmed desorption of methanol and water ices, photochemistry of gas-phase methanol, and detection of photodesorbed water from a pure water ice surface. Current work that will be discussed focuses on the detection of gas-phase CO and other photoproducts from an ice surface.

  8. Metabolic methanol: molecular pathways and physiological roles.

    Science.gov (United States)

    Dorokhov, Yuri L; Shindyapina, Anastasia V; Sheshukova, Ekaterina V; Komarova, Tatiana V

    2015-04-01

    Methanol has been historically considered an exogenous product that leads only to pathological changes in the human body when consumed. However, in normal, healthy individuals, methanol and its short-lived oxidized product, formaldehyde, are naturally occurring compounds whose functions and origins have received limited attention. There are several sources of human physiological methanol. Fruits, vegetables, and alcoholic beverages are likely the main sources of exogenous methanol in the healthy human body. Metabolic methanol may occur as a result of fermentation by gut bacteria and metabolic processes involving S-adenosyl methionine. Regardless of its source, low levels of methanol in the body are maintained by physiological and metabolic clearance mechanisms. Although human blood contains small amounts of methanol and formaldehyde, the content of these molecules increases sharply after receiving even methanol-free ethanol, indicating an endogenous source of the metabolic methanol present at low levels in the blood regulated by a cluster of genes. Recent studies of the pathogenesis of neurological disorders indicate metabolic formaldehyde as a putative causative agent. The detection of increased formaldehyde content in the blood of both neurological patients and the elderly indicates the important role of genetic and biochemical mechanisms of maintaining low levels of methanol and formaldehyde.

  9. Endogenous methanol regulates mammalian gene activity.

    Directory of Open Access Journals (Sweden)

    Tatiana V Komarova

    Full Text Available We recently showed that methanol emitted by wounded plants might function as a signaling molecule for plant-to-plant and plant-to-animal communications. In mammals, methanol is considered a poison because the enzyme alcohol dehydrogenase (ADH converts methanol into toxic formaldehyde. However, the detection of methanol in the blood and exhaled air of healthy volunteers suggests that methanol may be a chemical with specific functions rather than a metabolic waste product. Using a genome-wide analysis of the mouse brain, we demonstrated that an increase in blood methanol concentration led to a change in the accumulation of mRNAs from genes primarily involved in detoxification processes and regulation of the alcohol/aldehyde dehydrogenases gene cluster. To test the role of ADH in the maintenance of low methanol concentration in the plasma, we used the specific ADH inhibitor 4-methylpyrazole (4-MP and showed that intraperitoneal administration of 4-MP resulted in a significant increase in the plasma methanol, ethanol and formaldehyde concentrations. Removal of the intestine significantly decreased the rate of methanol addition to the plasma and suggested that the gut flora may be involved in the endogenous production of methanol. ADH in the liver was identified as the main enzyme for metabolizing methanol because an increase in the methanol and ethanol contents in the liver homogenate was observed after 4-MP administration into the portal vein. Liver mRNA quantification showed changes in the accumulation of mRNAs from genes involved in cell signalling and detoxification processes. We hypothesized that endogenous methanol acts as a regulator of homeostasis by controlling the mRNA synthesis.

  10. X-ray photodesorption from methanol ice

    Science.gov (United States)

    Andrade, D. P. P.; Rocco, M. L. M.; Boechat-Roberty, H. M.

    2010-12-01

    The abundances of molecules and ions depend on the mechanisms of their formation and destruction that can occur both in the gas phase and in the condensed phase on grain surfaces. Photodesorption of grain surface species may explain the relative high abundances of gaseous neutral or ionic species detected in cold environments. X-ray photons from young stars are able to penetrate cold and dense regions inside protoplanetary discs, leading to molecular dissociation and desorption of photo-products from icy molecules on grain mantles. This paper aims to experimentally investigate the contribution of ion desorption from methanol ice stimulated by soft X-rays for producing chemically active ions in protoplanetary discs. The measurements were carried out at the Brazilian synchrotron light source (LNLS), using X-ray photons at the methanol O1s resonance energy (537 eV). Some possible pathways for the H- and O- formation from singly charged desorbed ions are suggested. The photodesorption yields for positive and negative ions were determined and compared with previous results obtained using different ionization agents, such as electrons, heavy ions and photons at different energies. We also correlate our results to the ion production in protoplanetary discs.

  11. Towards a methanol economy based on homogeneous catalysis: methanol to H2 and CO2 to methanol.

    Science.gov (United States)

    Alberico, E; Nielsen, M

    2015-04-21

    The possibility to implement both the exhaustive dehydrogenation of aqueous methanol to hydrogen and CO2 and the reverse reaction, the hydrogenation of CO2 to methanol and water, may pave the way to a methanol based economy as part of a promising renewable energy system. Recently, homogeneous catalytic systems have been reported which are able to promote either one or the other of the two reactions under mild conditions. Here, we review and discuss these developments.

  12. Characterization and Modeling of a Methanol Reforming Fuel Cell System

    DEFF Research Database (Denmark)

    Sahlin, Simon Lennart

    topologies is the Reformed Methanol Fuel Cell (RMFC) system that operates on a mix of methanol and water. The fuel is reformed with a steam reforming to a hydrogen rich gas, however with additional formation of Carbon Monoxide and Carbon Dioxide. High Temperature Polymer Electrolyte Membrane Fuel Cell (HT...... to heat up the steam reforming process. However, utilizing the excess hydrogen in the system complicates the RMFC system as the amount of hydrogen can vary depending on the fuel methanol supply, fuel cell load and the reformer gas composition. This PhD study has therefore been involved in investigating......Many fuel cells systems today are operated with compressed hydrogen which has great benefits because of the purity of the hydrogen and the relatively simple storage of the fuel. However, compressed hydrogen is stored in the range of 800 bar, which can be expensive to compress.One of the interesting...

  13. Transesterification of rapeseed oil in supercritical methanol in a flow reactor

    Science.gov (United States)

    Anikeev, V. I.; Yakovleva, E. Yu.

    2012-11-01

    Transesterification reactions of rapeseed oil in supercritical methanol in a flow reactor over a wide range of variation of the methanol/oil ratio, pressure, and contact time are studied. Conditions ensuring selectivity and a high degree of rapeseed oil conversion are found. Experiments to study this reaction in the presence of zeolite heterogeneous catalyst are performed.

  14. METHANOL OXIDATION OVER AU/ γ -AL 2O3 CATALYSTS 149

    African Journals Online (AJOL)

    DR. AMINU

    Methanol adsorption and reaction was investigated over Au/γ-Al2O3 catalysts. The catalysts ... dehydration of methanol to dimethyl ether (DME) at about 150oC followed by decomposition of .... sample is selective to dehydration due to the high.

  15. Methanol masers and millimetre lines : a common origin in protostellar envelopes

    NARCIS (Netherlands)

    Torstensson, Karl Johan Erik

    2011-01-01

    In this thesis we study the earliest stages of high-mass star formation. Class II methanol masers are only associated with massive star formation and are a unique probe of these environments. Through observations we have studied where and when the methanol maser emission occur in relation to the pro

  16. New polymeric electrolyte membranes based on proton donor proton acceptor properties for direct methanol fuel cells

    NARCIS (Netherlands)

    Manea, G.C.; Mulder, M.H.V.

    2002-01-01

    In order to reduce the high methanol permeability of membranes in a direct methanol fuel cell application new and better materials are still required. In this paper membranes made from polybenzimidazole/sulfonated polysulfone are given and compared with homopolymer membranes made from sulfonated pol

  17. Characterization of polymer blends PES/SPSf and PES/SPEEK for direct methanol fuel cells

    NARCIS (Netherlands)

    Manea, G.C.; Mulder, M.H.V.

    2002-01-01

    Existing polymer electrolyte membranes (PEMs) applied for hydrogen fuel cells are frequently not suitable for direct methanol fuel cells due to the high methanol permeability. Therefore, new materials are required and in order to avoid laborious fuel cell experiments with a so-called membrane–electr

  18. A cheap, simple high throughput method for screening native Helicobacter pylori urease inhibitors using a recombinant Escherichia coli, its validation and demonstration of Pistacia atlantica methanolic extract effectivity and specificity.

    Science.gov (United States)

    Amar, Natalie; Peretz, Avi; Gerchman, Yoram

    2017-02-01

    Helicobacter pylori is the most frequent and persistent bacterial infection worldwide, and a risk factor for active gastritis, peptic ulcers, mucosa-associated lymphoid tissue lymphoma, and gastric cancer. Although combined antibiotics treatment is effective cases of antibiotic resistance are reported at an alarming rate. The H. pylori urease enzyme is essential for the bacteria establishment in the gastric mucosa, resulting urease inhibitors being sought after as effective and specific anti- H. pylori treatment. To-date, screening assays are based mostly on the analog plant urease enzyme but difference in properties of the plant and bacterial enzymes hamper these efforts. We have developed a screening assay based on recombinant Escherichia coli expressing native H. pylori urease, and validated this assay using thiourea and a methanolic extract of Pistacia atlantica. The assay demonstrated the thiourea and the extract to be potent urease inhibitors, with the extract having strong bacteriostatic activity against clinical isolates of H. pylori, including such with antibiotic resistance. The extract was also found to be neutral toward common probiotic bacteria, supporting its specificity and compatibility with digestive system desired microflora and suggesting it could be a good source for anti-H. pylori compounds. The assay has proven to be cheap, simple and native alternative to the plant enzyme based assay and could allow for high throughput screening for new urease inhibitors and could expedite screening and development of novel, better H. pylori remedies helping us to combat this infection.

  19. 高硫煤制甲醇净化废气回收利用制取食品级液体CO2%Recovery and Utilization of Purification Waste Gas of High Sulfur Coal for Methanol Plant

    Institute of Scientific and Technical Information of China (English)

    赵绍武; 张萍; 汪俊

    2012-01-01

    The waste gas of purification unit was recovered and utilized in the high sulfur coal to methanol plant. Using domestic advanced and efficient technology, the carbon dioxide content in waste gas was recovered and purified to obtain food grade liquid carbon dioxide. The problems found in operation were timely analysed and optimized. The construction and operation of the device realized energy saving and emission reduction of CO2 in coal chemical industry and meet the green, low - carbon sustainable development train of thought.%高硫煤制甲醇净化废气回收利用装置,采用国内先进技术高效回收净化废气中二氧化碳,制取食品级液体CO2,对装置开车过程中发现的问题及时分析优化整改。该装置建设运行,实现了CO2节能减排,符合煤化工产业绿色、低碳可持续发展思路。

  20. Determination of antioxidant activities, total phenolic and flavanoid contents in Bougainvillea glabra bracts at various methanol concentrations

    Science.gov (United States)

    Markandan, Shalini; Abdullah, Aminah; Musa, Khalid Hamid; Subramaniam, Vimala; Stockham, Katherine

    2016-11-01

    The Bougainvillea glabra bract was extracted using three ratios of methanolic solvents at 50%, 70% and 100%. In this study, the methanolic extracts of B. glabra bract were evaluated for antioxidant properties and quantification of phenolics and flavanoids. Methanol at 100% was the highest extraction efficiency among three other methanolic with yield value of 38%. The content of phenolics and flavonoids of B. glabra bracts in methanol 100% were 63.92±0.90 GAE mg/100g and 249.53±26.20 QE mg/100g respectively. The antioxidant activity was measured using three different bioassays namely, DPPH, ABTS and FRAP. The results were expressed as mg Trolox equivalent per 100 g where Trolox is a vitamin E analog. Among these methanol extracts, highest antioxidant capacity was observed in the pure methanol concentration. Positive correlation was observed in B. glabra bract between DPPH assay and TPC, r2=1.00. The methanol extract at 100% was rich in polyphenolics, which indicating that the B. glabra bract has the potential to be recommended as a good dietary source of natural antioxidants.

  1. The reaction of methyl peroxy and hydroxyl radicals as a major source of atmospheric methanol

    Science.gov (United States)

    Müller, Jean-François; Liu, Zhen; Nguyen, Vinh Son; Stavrakou, Trissevgeni; Harvey, Jeremy N.; Peeters, Jozef

    2016-10-01

    Methyl peroxy, a key radical in tropospheric chemistry, was recently shown to react with the hydroxyl radical at an unexpectedly high rate. Here, the molecular reaction mechanisms are elucidated using high-level quantum chemical methodologies and statistical rate theory. Formation of activated methylhydrotrioxide, followed by dissociation into methoxy and hydroperoxy radicals, is found to be the main reaction pathway, whereas methylhydrotrioxide stabilization and methanol formation (from activated and stabilized methylhydrotrioxide) are viable minor channels. Criegee intermediate formation is found to be negligible. Given the theoretical uncertainties, useful constraints on the yields are provided by atmospheric methanol measurements. Using a global chemistry-transport model, we show that the only explanation for the high observed methanol abundances over remote oceans is the title reaction with an overall methanol yield of ~30%, consistent with the theoretical estimates given their uncertainties. This makes the title reaction a major methanol source (115 Tg per year), comparable to global terrestrial emissions.

  2. Highly Depleted Ethane and Slightly Depleted Methanol in Comet 21P/Giacobini-Zinner: Application of Empirical g-Factors for CH3OH Near 50K

    Science.gov (United States)

    DiSanti, Michael A.; Bonev, Boncho P.; Mumma, Michael J.; Villanueva, Geronimo L.

    2010-01-01

    We report high resolution (lambda/delta lambda approximately 24,000) observations of Comet 21 P/Giacobini-Zinner (21P) between approximately 2.85 -- 3.54 micrometers, obtained with NIRSPEC at Keck 2 on UT 2005 June 03 (R(sub h) = 1.12 AU, delta = 1.45 AU). These simultaneously sampled multiple emissions from the v7 band of C2H6 and the v2 and v3 bands of CH3OH, together with several hot bands of H2O, permitting a direct measure of parent volatile abundances in 21P. Our spectra reveal highly depleted C2H6 (0.13-0.14 percent relative to H2O) and CH3OH/C2H6 approximately 10, consistent with previously published abundances from observations in the IR [1,2] and millimeter sub-mm (reporting CH3OH/H2O [3]) during its previous apparition in 1998. We observed similarly high CH3OH/C2H6, and also similar rotational temperature to that measured for 21 P, in Comet 8P/Tuttle [4,5]. We used our (higher signal-to-noise) NIRSPEC observations of 8P to produce effective (empirical) CH3OH g-factors for several lines in the v2 band. These will be presented together with interpretation of our results, including constraints on the spin temperature of water. We acknowledge support from the NASA Planetary Atmospheres, Planetary Astronomy, and Astrobiology Programs and from the NSF Astronomy and Astrophysics Research Grants Program.

  3. Efficient degradation of malathion in the presence of detergents using an engineered organophosphorus hydrolase highly expressed by Pichia pastoris without methanol induction.

    Science.gov (United States)

    Bai, Yun-Peng; Luo, Xiao-Jing; Zhao, Yu-Lian; Li, Chun-Xiu; Xu, Dian-Sheng; Xu, Jian-He

    2017-09-26

    The biodegradation of pesticides by organophosphorus hydrolases (OPHs) requires an efficient enzyme production technology in industry. Herein, a Pichia pastoris strain was constructed for the extracellular expression of PoOPHM9, an engineered malathion-degrading enzyme. After optimization, the maximum titer and yield of fermentation reached 50.8 kU/L and 4.1 gprotein/L after 3 days, with the highest space-time yield (STY) reported so far, 640 U∙L(-1)∙h(-1). PoOPHM9 displayed its high activity and stability in the presence of 0.1% (w/w) plant-derived detergent. Only 0.04 mg/mL enzyme could completely remove 0.15 mM malathion in aqueous solution within 20 min. Furthermore, 12 μmol malathion on apples and cucumbers surfaces was completely removed by 0.05 mg/mL PoOPHM9 in tap water after 35 min washing. The efficient production of the highly active PoOPHM9 has cleared a major barrier to biodegradation of pesticide residues in food industry.

  4. Isomerically Pure Tetramethylrhodamine Voltage Reporters.

    Science.gov (United States)

    Deal, Parker E; Kulkarni, Rishikesh U; Al-Abdullatif, Sarah H; Miller, Evan W

    2016-07-27

    We present the design, synthesis, and application of a new family of fluorescent voltage indicators based on isomerically pure tetramethylrhodamines. These new Rhodamine Voltage Reporters, or RhoVRs, use photoinduced electron transfer (PeT) as a trigger for voltage sensing, display excitation and emission profiles in the green to orange region of the visible spectrum, demonstrate high sensitivity to membrane potential changes (up to 47% ΔF/F per 100 mV), and employ a tertiary amide derived from sarcosine, which aids in membrane localization and simultaneously simplifies the synthetic route to the voltage sensors. The most sensitive of the RhoVR dyes, RhoVR 1, features a methoxy-substituted diethylaniline donor and phenylenevinylene molecular wire at the 5'-position of the rhodamine aryl ring, exhibits the highest voltage sensitivity to date for red-shifted PeT-based voltage sensors, and is compatible with simultaneous imaging alongside green fluorescent protein-based indicators. The discoveries that sarcosine-based tertiary amides in the context of molecular-wire voltage indicators prevent dye internalization and 5'-substituted voltage indicators exhibit improved voltage sensitivity should be broadly applicable to other types of PeT-based voltage-sensitive fluorophores.

  5. Hybridization and control of a mobile direct methanol fuel cell system; Hybridisierung und Regelung eines mobilen Direktmethanol-Brennstoffzellen-Systems

    Energy Technology Data Exchange (ETDEWEB)

    Wilhelm, Joerg Christoph

    2010-07-01

    Direct methanol fuel cells (DMFCs) are characterized by the fact that they directly convert the chemical energy of the liquid fuel methanol into electrical energy. Methanol has a high energy density and can be stored relatively easily. Due to these advantages, direct methanol fuel cell systems are suitable, for example, as a battery replacement for light-traction applications in the kW class. Since refuelling is much faster than recharging a battery, almost interruption-free operation is possible. The aim of this thesis is therefore to develop a direct methanol fuel cell system for light-traction applications. The systems technology development and characterization of a mobile direct methanol fuel cell system is initially examined in general and then applied to the example of a horizontal order picker, a type of forklift truck. A hybridization and control concept is developed for this type of truck. The procedure is structured into the theoretical characterization of the application, the development of theoretical concepts and a concluding systems analysis using data from the test stand and simulations. The characteristic driving cycle of the application results from the characterization. The concept development is based on key data such as maximum peak power during acceleration and braking as well as average power. The two-stage theoretical development of a hybridization concept is based on a pure fuel cell vehicle. A systems analysis of all possible concepts with respect to the criteria of fuel cell power, total system efficiency and dynamic fuel cell loading eventually leads to the preferred concept of indirect coupling. A cascade controller with map control, the control concept developed for this purpose, keeps the energy storage unit at a constant state of charge and provides for the fuel cell aging protection as well as aging detection. The driving cycle, operational states of the vehicle and the efficiencies of the individual components play a decisive role

  6. Discovery of two new methanol masers in NGC 7538

    CERN Document Server

    Pestalozzi, M; Minier, V; Motte, F

    2006-01-01

    Context: NGC7538 is known to host a 6.7 and 12.2GHz methanol maser cospatial with a Ultra Compact (UC) HII region, IRS1. Aims: We report on the serendipitous discovery of two additional 6.7GHz methanol masers in the same region, not associated with IRS1. Methods: Interferometry maser positions are compared with recent single-dish and interferometry continuum observations. Results: The positions of the masers agree to high accuracy with the 1.2mm continuum peak emission in NGC7538 IRS9 and NGC7538 S. This clear association is also confirmed by the positional agreement of the masers with existing high resolution continuum observations at cm and/or mm wavelengths. Conclusions: Making use of the established strong relation between methanol masers and high-mass star formation, we claim that we have accurately positioned the high-mass protostars within the regions where they are detected. The variety of objects hosting a 6.7GHz methanol maser in NGC7538 shows that this emission probably traces different evolutionar...

  7. 纯棉细号高密紧密纱织物无PVA上浆体会%Experience of Sizing Pure Cotton Fine Count High Density Compact Yarn Fabric without PVA

    Institute of Scientific and Technical Information of China (English)

    周祥

    2012-01-01

    Sizing processing of pure cotton fine count high density compact yarn fabric without PVA was discussed. Compact yarn sizing key points were analyzed. Sizing and size film properties were contrasted in condition of adopting PVA and no PVA. Sizing test was done on compact yarn. Test test shows that sizing of pure cotton fine count high density compact yarn fabric without PVA can be realized through setting sizing processing rationally, ensuring sizing hairiness, strength and elongation in better state.%探讨纯棉细号高密紧密纱织物无PVA上浆工艺.分析了紧密纱上浆的要点,对比了含PVA浆料配方与无PVA浆料配方的浆液与浆膜性能,对紧密纱进行了上浆试验.试验证明,通过合理设置上浆工艺,保证浆纱毛羽、强力及伸长处于较佳状态,可以实现纯棉细号高密紧密纱织物的无PVA上浆.

  8. Sizing Practice of Using DH-PVA on Pure Cotton Superfine High Density Fabric%DH-PVA用于纯棉特细号高密织物的上浆实践

    Institute of Scientific and Technical Information of China (English)

    张平; 余爱琴; 杨建强

    2009-01-01

    Feasibility of using DH-PVA to size pure cotton superfine high density fabric was discussed. Three pure cotton superfine high density fabrics were sized by DH-PVA. The sizing effects and weaving effects of applying DH-PVA new formula and PVA-1799,PVA-0588 raw formulas were contrasted. The result shows when DH-PVA was used loom ef-ficiency could be improved while PVA-1799 could be used less or be avoided. Sizing cost could be reduced by reducing acrylic size mixture and oil smoothing agent properly.%探讨DH-PVA用于纯棉特细号高密织物上浆的可行性.应用DH-PVA对三种纯棉特细号高密织物进行了浆纱实践,对应用DH-PVA的新配方与应用PVA-1799、PVA-0588的原配方的浆纱效果及织造效果进行了对比,结果表明:应用DH-PVA可以在保证织机效率有所提高的前提下少用或不用PVA-1799,适当降低丙烯酸类浆料、油脂类平滑剂用量,从而降低浆纱成本.

  9. High-Strain Rate Tensile Behavior of Pure Aluminum Single and Multi-Crystalline Materials with a Tensile Split Hopkinson Bar

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Sangyul [Samsung Electro-Mechanics, Suwon (Korea, Republic of); Jang, Jin Hee; Yoon, Hyo Jun; Kim, Ki Tae [Pohang Univ. of Science and Technology, Pohang (Korea, Republic of)

    2016-01-15

    In this study, we modified the conventional tensile split Hopkinson bar(TSHB) apparatus typically used for the high strength steel to evaluate the tensile deformation behavior of soft metallic sheet materials under high strain rates. Stress-strain curves of high purity single and multi-crystalline materials were obtained using this experimental procedure. Grain morphology and initial crystallographic orientation were characterized by EBSD(Electron Backscattered Diffraction) method measured in a FE-SEM(Field emission-scanning electron microscopy). The fractured surfaces were observed by using optical microscopy. The relationship between plastic deformation of aluminum crystalline materials under high-strain rates and the initial microstructure and the crystallographic orientations has been addressed.

  10. Improvement of biodiesel methanol blends

    Directory of Open Access Journals (Sweden)

    Y. Datta Bharadwaz

    2016-06-01

    Full Text Available The main objective of this work was to improve the performance of biodiesel–methanol blends in a VCR engine by using optimized engine parameters. For optimization of the engine, operational parameters such as compression ratio, fuel blend, and load are taken as factors, whereas performance parameters such as brake thermal efficiency (Bth and brake specific fuel consumption (Bsfc and emission parameters such as carbon monoxide (CO, unburnt hydrocarbons (HC, Nitric oxides (NOx and smoke are taken as responses. Experimentation is carried out as per the design of experiments of the response surface methodology. Optimization of engine operational parameters is carried out using Derringers Desirability approach. From the results obtained it is inferred that the VCR engine has maximum performance and minimum emissions at 18 compression ratio, 5% fuel blend and at 9.03 kg of load. At this optimized operating conditions of the engine the responses such as brake thermal efficiency, brake specific fuel consumption, carbon monoxide, unburnt hydrocarbons, nitric oxide, and smoke are found to be 31.95%, 0.37 kg/kW h, 0.036%, 5 ppm, 531.23 ppm and 15.35% respectively. It is finally observed from the mathematical models and experimental data that biodiesel methanol blends have maximum efficiency and minimum emissions at optimized engine parameters.

  11. VLT/ISAAC infrared spectroscopy of embedded high-mass YSOs in the Large Magellanic Cloud: Methanol and the 3.47 micron band

    CERN Document Server

    Shimonishi, Takashi; Onaka, Takashi; Boulanger, François

    2016-01-01

    This study aims to elucidate a possible link between chemical properties of ices in star-forming regions and environmental characteristics of the host galaxy. We performed 3--4 micron spectroscopic observations toward nine embedded high-mass YSOs in the Large Magellanic Cloud (LMC) with the ISAAC at the VLT. Additionally, we analyzed archival ISAAC data of two LMC YSOs. As a result, we detected absorption bands due to solid H2O and CH3OH as well as the 3.47 micron absorption band. The 3.53 micron CH3OH ice absorption band for the LMC YSOs is found to be absent or very weak compared to that seen toward Galactic sources. The result suggests the low abundance of CH3OH ice in the LMC. The 3.47 micron absorption band is detected toward six out of eleven LMC YSOs. We found that the 3.47 micron band and the H2O ice band correlate similarly between the LMC and Galactic samples, but the LMC sources seem to require a slightly higher H2O ice threshold for the appearance of the 3.47 micron band. For the LMC sources with ...

  12. Real-time high-resolution X-ray imaging and nuclear magnetic resonance study of the hydration of pure and Na-doped C3A in the presence of sulfates

    Energy Technology Data Exchange (ETDEWEB)

    Kirchheim,, A. P.; Dal Molin, D.C.; Emwas, Abdul-Hamid; Provis, J.L.; Fischer, P.; Monteiro, P.J.M.

    2010-12-01

    This study details the differences in real-time hydration between pure tricalcium aluminate (cubic C{sub 3}A or 3CaO {center_dot} Al{sub 2}O{sub 3}) and Na-doped tricalcium aluminate (orthorhombic C{sub 3}A or Na{sub 2}Ca{sub 8}Al{sub 6}O{sub 18}), in aqueous solutions containing sulfate ions. Pure phases were synthesized in the laboratory to develop an independent benchmark for the reactions, meaning that their reactions during hydration in a simulated early age cement pore solution (saturated with respect to gypsum and lime) were able to be isolated. Because the rate of this reaction is extremely rapid, most microscopy methods are not adequate to study the early phases of the reactions in the early stages. Here, a high-resolution full-field soft X-ray imaging technique operating in the X-ray water window, combined with solution analysis by {sup 27}Al nuclear magnetic resonance (NMR) spectroscopy, was used to capture information regarding the mechanism of C{sub 3}A hydration during the early stages. There are differences in the hydration mechanism between the two types of C{sub 3}A, which are also dependent on the concentration of sulfate ions in the solution. The reactions with cubic C{sub 3}A (pure) seem to be more influenced by higher concentrations of sulfate ions, forming smaller ettringite needles at a slower pace than the orthorhombic C{sub 3}A (Na-doped) sample. The rate of release of aluminate species into the solution phase is also accelerated by Na doping.

  13. Real-time high-resolution X-ray imaging and nuclear magnetic resonance study of the hydration of pure and Na-doped C3A in the presence of sulfates

    KAUST Repository

    Kirchheim, A. P.

    2011-02-21

    This study details the differences in real-time hydration between pure tricalcium aluminate (cubic C3A or 3CaO·Al2O 3) and Na-doped tricalcium aluminate (orthorhombic C3A or Na2Ca8Al6O18), in aqueous solutions containing sulfate ions. Pure phases were synthesized in the laboratory to develop an independent benchmark for the reactions, meaning that their reactions during hydration in a simulated early age cement pore solution (saturated with respect to gypsum and lime) were able to be isolated. Because the rate of this reaction is extremely rapid, most microscopy methods are not adequate to study the early phases of the reactions in the early stages. Here, a high-resolution full-field soft X-ray imaging technique operating in the X-ray water window, combined with solution analysis by 27Al nuclear magnetic resonance (NMR) spectroscopy, was used to capture information regarding the mechanism of C3A hydration during the early stages. There are differences in the hydration mechanism between the two types of C3A, which are also dependent on the concentration of sulfate ions in the solution. The reactions with cubic C3A (pure) seem to be more influenced by higher concentrations of sulfate ions, forming smaller ettringite needles at a slower pace than the orthorhombic C3A (Na-doped) sample. The rate of release of aluminate species into the solution phase is also accelerated by Na doping. © 2011 American Chemical Society.

  14. Proton-exchange sulfonated poly(ether ether ketone)(SPEEK)/SiOx-s composite membranes in direct methanol fuel cells%DMFCs用SPEEK/SiOx-S复合质子交换膜

    Institute of Scientific and Technical Information of China (English)

    高启君; 王宇新; 许莉; 卫国强; 王志涛

    2009-01-01

    A sulfonated poly(ether ether ketone)(SPEEK)membrane with a fairly high degree of SUl fonation (DS)can swell excessively and even dissolve at high temperature.To solve these problems,insolvable functionalized silica powder with suIlbnic acid groups(SiOx-S)was added into the SPEEK matrix(DS=55.1%) to prepare SPEEK/SiOx-S composite membranes.The decrease in both the swelling degree and the methanol permeability of the membranes was a dose-dependent result of addition of the SiOx-S powder.Pure SPEEK membrane swelled 52.6%at 80°C,whereas the SPEEK/SiOx-S(1 5%,by mass)membrane swelled only 27.3%at the same temperature.From room temperature to 80℃,all SPEEK/SPEEK/SiOx-S composite membranes had methanol petea-bility of about one order of magnitude lower than that of Nafion r 115.Compared with pure SPEEK membranes,the addition of the SiOx-S powder not only leads to higher proton conductivity,but also increascs the dimensional stability at higher temperatures,and grcater proton conductivity can bc achieved at higher temperature.The SPEEK/SiOx-S(20%,by mass)membrane could withstand temperature up to 145°C,at which in 100%relative humidity(RH) its proton branc dissolved at 90°C.The SPFEk/SiOx-S composite membranes are promising for use in direct methanol fuel cells because of their good dimensional stability,high proton conductivity,and low methanol permeability.

  15. Early time excited-state structural evolution of pyranine in methanol revealed by femtosecond stimulated Raman spectroscopy.

    Science.gov (United States)

    Wang, Yanli; Liu, Weimin; Tang, Longteng; Oscar, Breland; Han, Fangyuan; Fang, Chong

    2013-07-25

    To understand chemical reactivity of molecules in condensed phase in real time, a structural dynamics technique capable of monitoring molecular conformational motions on their intrinsic time scales, typically on femtoseconds to picoseconds, is needed. We have studied a strong photoacid pyranine (8-hydroxypyrene-1,3,6-trisulfonic acid, HPTS, pK(a)* ≈ 0) in pure methanol and observed that excited-state proton transfer (ESPT) is absent, in sharp contrast with our previous work on HPTS in aqueous solutions wherein ESPT prevails following photoexcitation. Two transient vibrational marker bands at ~1477 (1454) and 1532 (1528) cm(-1) appear in CH3OH (CD3OD), respectively, rising within the instrument response time of ~140 fs and decaying with 390-470 (490-1400) fs and ~200 ps time constants in CH3OH (CD3OD). We attribute the mode onset to small-scale coherent proton motion along the pre-existing H-bonding chain between HPTS and methanol, and the two decay stages to the low-frequency skeletal motion-modulated Franck-Condon relaxation within ~1 ps and subsequent rotational diffusion of H-bonding partners in solution before fluorescence. The early time kinetic isotope effect (KIE) of ~3 upon methanol deuteration argues active proton motions particularly within the first few picoseconds when coherent skeletal motions are underdamped. Pronounced quantum beats are observed for high-frequency modes consisting of strong phenolic COH rocking (1532 cm(-1)) or H-out-of-plane wagging motions (952 cm(-1)) due to anharmonic coupling to coherent low-frequency modes impulsively excited at ca. 96, 120, and 168 cm(-1). The vivid illustration of atomic motions of HPTS in varying H-bonding geometry with neighboring methanol molecules unravels the multidimensional energy relaxation pathways immediately following photoexcitation, and provides compelling evidence that, in lieu of ESPT, the photoacidity of HPTS promptly activates characteristic low-frequency skeletal motions to search phase

  16. Two 3D structured Co-Ni bimetallic oxides as cathode catalysts for high-performance alkaline direct methanol fuel cells

    Science.gov (United States)

    Liu, Yan; Shu, Chengyong; Fang, Yuan; Chen, Yuanzhen; Liu, Yongning

    2017-09-01

    Two NiCo2O4 bimetallic oxides were synthesized via a facile hydrothermal method. SEM and TEM observations show that these materials have three-dimensional (3D) dandelion-like (DL) and flower-like (FL) morphologies. Their large specific surface areas (90.68 and 19.8 m2·g-1) and porous structures provide many active sites and effective transport pathways for the oxygen reduction reaction (ORR). Electrochemical measurements with a rotating ring-disc electrode (RRDE) indicate that the electron transfer numbers of the NiCo2O4-DL and NiCo2O4-FL catalysts for ORR in an alkaline solution are 3.97 and 3.91, respectively. Fuel cells were assembled with the bimetallic oxides, PtRu/C and a polymer fiber membrane (PFM) as cathode catalysts, anode catalyst and electrolyte film, respectively. For NiCo2O4-DL, the peak power density reaches up to 73.5 mW·cm-2 at 26 °C, which is the highest room-temperature value reported to date. The high catalytic activity of NiCo2O4 is mainly attributed to the presence of many Co3+ cations that directly donate electrons to O2 to reduce it via a more efficient and effective route. Furthermore, the catalytic performance of NiCo2O4-DL is superior to that of NiCo2O4-FL because it has a higher specific surface area and is less crystalline.

  17. Study of impurity distribution in mechanically polished, chemically treated and ultra-high vacuum degassed pure Niobium samples using TOFSIMS technique

    CERN Document Server

    Bose, A

    2015-01-01

    The performance of Superconducting radio frequency cavities (SCRF) are highly dependent on the surface treatment processes, which in turn is influenced by the chemistry within the penetration depth of Niobium (Nb). The present study analyses various impurities within the RF penetration depth (~50nm) of Nb samples treated by SCRF cavity processing techniques like colloidal silica polishing (simulating centrifugal barrel polishing), buffer chemical polishing (BCP), high pressure rinsing (HPR) and degassing under ultra high vacuum (UHV) condition at 600{\\deg}C for 10hrs. Various modes of Time of flight secondary ion mass spectrometry (TOFSIMS) technique was employed to study the effect of the above treatments on the vast spectrum of impurities that include interstitials, hydrocarbons, oxides, acidic residuals, reaction products and metallic impurities. UHV degassing treatment was the only treatment capable of reducing hydrogen contamination, but, it led to extensive oxygen, carbon and metallic impurities in the ...

  18. High-temperature shock tube and modeling studies on the reactions of methanol with D-atoms and CH3-radicals.

    Science.gov (United States)

    Peukert, S L; Michael, J V

    2013-10-10

    The shock tube technique has been used to study the hydrogen abstraction reactions D + CH3OH → CH2O + H + HD (A) and CH3 + CH3OH → CH2O + H + CH4 (B). For reaction A, the experiments span a T-range of 1016 K ≤ T ≤ 1325 K, at pressures 0.25 bar ≤ P ≤ 0.46 bar. The experiments on reaction B, CH3 + CH3OH, cover a T-range of 1138 K ≤ T ≤ 1270 K, at pressures around 0.40 bar. Reflected shock tube experiments, monitoring the depletion of D-atoms by applying D-atom atomic resonance absorption spectrometry (ARAS), were performed on reaction A using gas mixtures of C2D5I and CH3OH in Kr bath gas. C2D5I was used as precursor for D-atoms. For reaction B, reflected shock tube experiments monitoring H-atom formation with H-ARAS, were carried out using gas mixtures of diacetyl ((CH3CO)2) and CH3OH in Kr bath gas. (CH3CO)2 was used as the source of CH3-radicals. Detailed reaction models were assembled to fit the D-atom and H-atom time profiles in order to obtain experimental rate constants for reactions A and B. Total rate constants from the present experiments on D + CH3OH and CH3 + CH3OH can be represented by the Arrhenius equations kA(T) = 1.51 × 10(-10) exp(-3843 K/T) cm(3) molecules(-1) s(-1) (1016 K ≤ T ≤ 1325 K) and kB(T) = 9.62 × 10(-12) exp(-7477 K/T) cm(3) molecules(-1) s(-1) (1138 K ≤ T ≤ 1270 K). The experimentally obtained rate constants were compared with available rate data from the literature. The results from quantum chemical studies on reaction A were found to be in good agreement with the present results. The present work represents the first direct experimental study on these bimolecular reactions at combustion temperatures and is important to the high-temperature oxidation of CH3OH.

  19. Atomic-Scale Origin of Long-Term Stability and High Performance of p-GaN Nanowire Arrays for Photocatalytic Overall Pure Water Splitting.

    Science.gov (United States)

    Kibria, Md Golam; Qiao, Ruimin; Yang, Wanli; Boukahil, Idris; Kong, Xianghua; Chowdhury, Faqrul Alam; Trudeau, Michel L; Ji, Wei; Guo, Hong; Himpsel, F J; Vayssieres, Lionel; Mi, Zetian

    2016-10-01

    The atomic-scale origin of the unusually high performance and long-term stability of wurtzite p-GaN oriented nanowire arrays is revealed. Nitrogen termination of both the polar (0001¯) top face and the nonpolar (101¯0) side faces of the nanowires is essential for long-term stability and high efficiency. Such a distinct atomic configuration ensures not only stability against (photo) oxidation in air and in water/electrolyte but, as importantly, also provides the necessary overall reverse crystal polarization needed for efficient hole extraction in p-GaN.

  20. Three-dimensional ordered macroporous platinum-based electrode for methanol oxidation

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this paper, three-dimensional ordered macroporous platinum catalysts with high real surface area were synthesized using the inverted colloidal crystals template technique and have been employed for the electrooxidation of methanol. The morphology and electrocatalytic behavior of the porous Pt electrodes were investigated with atomic force microscopy and electrochemical techniques. For the same amount of Pt deposited, the real surface areas of the electrodes are 9.16 and 8.00 cm2 for the porous electrodes with pore size of 320 and 500 nm respectively, which are more than 5 times larger than the directly deposited Pt electrode (1.4 cm2). The pore size effect on the methanol electrooxidation was investigated by testing low concentration solution of methanol and porous materials with different pore sizes. The synthesized macroporous Pt electrode shows high stability toward the electrooxidation of methanol and is promising for the direct methanol fuel cell.

  1. Photoionizaton of Pure and Doped Helium Nanodroplets

    CERN Document Server

    Mudrich, M

    2014-01-01

    Helium nanodroplets, commonly regarded as the "nearly ideal spectroscopic matrix", are being actively studied for more than two decades now. While they mostly serve as cold, weakly perturbing and transparent medium for high-resolution spectroscopy of embedded molecules, their intrinsic quantum properties such as microscopic superfluidity still are subject-matter of current research. This article reviews recent work on pure and doped He nanodroplets using PI spectroscopy, an approach which has greatly advanced in the past years. While the notion of the ideal spectroscopic matrix mostly no longer holds in this context, photoionization techniques provide detailed insights into the photo-physical properties of pure and doped He nanodroplets and their relaxation dynamics following electronic excitation. Exploiting nowadays available high laser fields, even highly ionized states of matter on the nanoscale can be formed. Our particular focus lies on recent experimental progress including fs time-resolved spectroscop...

  2. First-order melting transition observed from resistivity measurements in ultra-pure YBa2Cu3O7-δ single crystals with high twin boundary density

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Eltsev, Y.; Andersson, M.

    1999-01-01

    R(T) measurements have been performed on optimally and overdoped heavily twinned high-purity YBa2Cu3O7-delta single crystals, under a magnetic field B oriented parallel to the twin boundary planes (B parallel to c). The characteristic feature attributed to the flux line lattice melting transition...

  3. Building carbon-carbon bonds using a biocatalytic methanol condensation cycle.

    Science.gov (United States)

    Bogorad, Igor W; Chen, Chang-Ting; Theisen, Matthew K; Wu, Tung-Yun; Schlenz, Alicia R; Lam, Albert T; Liao, James C

    2014-11-11

    Methanol is an important intermediate in the utilization of natural gas for synthesizing other feedstock chemicals. Typically, chemical approaches for building C-C bonds from methanol require high temperature and pressure. Biological conversion of methanol to longer carbon chain compounds is feasible; however, the natural biological pathways for methanol utilization involve carbon dioxide loss or ATP expenditure. Here we demonstrated a biocatalytic pathway, termed the methanol condensation cycle (MCC), by combining the nonoxidative glycolysis with the ribulose monophosphate pathway to convert methanol to higher-chain alcohols or other acetyl-CoA derivatives using enzymatic reactions in a carbon-conserved and ATP-independent system. We investigated the robustness of MCC and identified operational regions. We confirmed that the pathway forms a catalytic cycle through (13)C-carbon labeling. With a cell-free system, we demonstrated the conversion of methanol to ethanol or n-butanol. The high carbon efficiency and low operating temperature are attractive for transforming natural gas-derived methanol to longer-chain liquid fuels and other chemical derivatives.

  4. Testing maser-based evolutionary schemes: A new search for 37.7-GHz methanol masers

    CERN Document Server

    Ellingsen, S P; Voronkov, M A; Dawson, J R

    2012-01-01

    We have used the Australia Telescope National Facility Mopra 22-m antenna to search for 37.7-GHz (7(-2) - 8(-1}E) methanol masers towards a sample of thirty six class II methanol masers. The target sources are the most luminous class II methanol masers not previously searched for this transition, with isotropic peak 12.2-GHz maser luminosity greater than 250 Jy/kpc^2 and isotropic peak 6.7-GHz maser luminosity greater than 800 Jy/kpc^2. Seven new 37.7-GHz methanol masers were detected as a result of the search. The detection rate for 37.7-GHz methanol masers towards a complete sample of all such class II methanol maser sites south of declination -20 deg is at least 30 percent. The relatively high detection rate for this rare methanol transition is in line with previous predictions that the 37.7-GHz transition is associated with a late stage of the class II methanol maser phase of high-mass star formation. We find that there is a modest correlation between the ratio of the 6.7- and 37.7-GHz maser peak intensit...

  5. Methanol ice VUV photoprocessing: GC-MS analysis of volatile organic compounds

    Science.gov (United States)

    Abou Mrad, Ninette; Duvernay, Fabrice; Chiavassa, Thierry; Danger, Grégoire

    2016-05-01

    Next to water, methanol is one of the most abundant molecules in astrophysical ices. A new experimental approach is presented here for the direct monitoring via gas chromatography coupled to mass spectrometry (GC-MS) of a sublimating photoprocessed pure methanol ice. Unprecedentedly, in a same analysis, compelling evidences for the formation of 33 volatile organic compounds are provided. The latter are C1-C6 products including alcohols, aldehydes, ketones, esters, ethers and carboxylic acids. Few C3 and all C4 detected compounds have been identified for the first time. Tentative detections of few C5 and C6 compounds are also presented. GC-MS allows for the first time the direct quantification of C2-C4 photoproducts and shows that their abundances decrease with the increase of their carbon chain length. These qualitative and quantitative measurements provide important complementary results to previous experiments, and present interesting similarities with observations of sources rich in methanol.

  6. An alkaline one-pot reaction to synthesize luminescent Eu-BTC MOF nanorods, highly pure and water-insoluble, under room conditions

    Science.gov (United States)

    Medina-Velazquez, D. Y.; Alejandre-Zuniga, B. Y.; Loera-Serna, S.; Ortiz, E. M.; Morales-Ramirez, A. de J.; Garfias-Garcia, E.; Garcia-Murillo, A.; Falcony, C.

    2016-12-01

    The increasing demand for optoelectronic devices requires the development of luminescent materials with high luminescence efficiency and low energy demands, and the metalorganic frameworks (MOFs) with lanthanides ions offer great potential in this area. The metalorganic materials provide properties of flexibility, low density, low-cost methods of synthesis, and insolubility in water, which gives them an advantage over traditional phosphors. In this study, a benzenetricarboxylate ligand (BTC) with a Eu3+ MOF was synthesized, and its structural and luminescent properties were measured. The metalorganic compound was generated in a one-pot reaction from europium nitrate and trimesic acid precursors. Through characterization by X-ray diffraction powder, infrared spectroscopy, SEM structural characterization, and luminescent spectroscopy, the formation of Europium benzenetricarboxylate (Eu-BTC) MOF nanorods was tested and the calculated value was in the range of 30-60 nm. A red luminescent emission with high intensity was observed for all the procedures.

  7. Retention of ionisable compounds on high-performance liquid chromatography XIX. pH variation in mobile phases containing formic acid, piperazine and tris as buffering systems and methanol as organic modifier.

    Science.gov (United States)

    Subirats, Xavier; Bosch, Elisabeth; Rosés, Martí

    2009-07-10

    In previous works a model to estimate the pH of methanol-aqueous buffer mobile phases from the aqueous pH and concentration of the buffer and the fraction of organic modifier was developed. This model was successfully applied and validated for buffers prepared from ammonia, acetic, phosphoric and citric acids. In the present communication this model has been extended to formic acid, piperazine and tris(hydroxymethyl)aminomethane buffers. Prior to the modelling work, the pK(a) values of the studied buffers at several methanol-water compositions were determined.

  8. Process assessment of small scale low temperature methanol synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Hendriyana [Chemical Engineering Department, Faculty of Engineering, Jenderal Achmad Yani Univerity (Indonesia); Chemical Engineering Department, Faculty of Industrial Technology, InstitutTeknologi Bandung (Indonesia); Susanto, Herri, E-mail: herri@che.itb.ac.id; Subagjo [Chemical Engineering Department, Faculty of Industrial Technology, InstitutTeknologi Bandung (Indonesia)

    2015-12-29

    Biomass is a renewable energy resource and has the potential to make a significant impact on domestic fuel supplies. Biomass can be converted to fuel like methanol via several step process. The process can be split into following main steps: biomass preparation, gasification, gas cooling and cleaning, gas shift and methanol synthesis. Untill now these configuration still has a problem like high production cost, catalyst deactivation, economy of scale and a huge energy requirements. These problems become the leading inhibition for biomass conversion to methanol, which should be resolved to move towards the economical. To address these issues, we developed various process and new configurations for methanol synthesis via methyl formate. This configuration combining two reactors: the one reactor for the carbonylation of methanol and CO to form methyl formate, and the second for the hydrogenolysis of methyl formate and H{sub 2} to form two molecule of methanol. Four plant process configurations were compared with the biomass basis is 300 ton/day. The first configuration (A) is equipped with a steam reforming process for converting methane to CO and H{sub 2} for increasing H{sub 2}/CO ratio. CO{sub 2} removal is necessary to avoid poisoning the catalyst. COSORB process used for the purpose of increasing the partial pressure of CO in the feed gas. The steam reforming process in B configuration is not used with the aim of reducing the number of process equipment, so expect lower investment costs. For C configuration, the steam reforming process and COSORB are not used with the aim of reducing the number of process equipment, so expect lower investment costs. D configuration is almost similar to the configuration A. This configuration difference is in the synthesis of methanol which was held in a single reactor. Carbonylation and hydrogenolysis reactions carried out in the same reactor one. These processes were analyzed in term of technical process, material and energy

  9. Experience of applying the results of investigations into controlling lines of the salt ratio between the salt and pure sections of high-pressure drum boilers

    Science.gov (United States)

    Fedorov, A. I.

    2013-12-01

    Layouts of the connection of the salt ratio lines (SRLs) existing in domestic boiler building are analyzed and the main causes of their low operational efficiency are shown. The results of investigation of hydraulics and the salt mode of an internal boiler layout with the SRL of the TPE-208 boiler are presented. Recommendations on designing the SRL in internal boiler layouts of high-pressure drum boilers, which make it possible to increase the reliability of boilers and to decrease the annual consumption of phosphates, are developed.

  10. Relativity of pure states entanglement

    CERN Document Server

    Zyczkowski, K; Zyczkowski, Karol; Bengtsson, Ingemar

    2002-01-01

    Entanglement of any pure state of an N times N bi-partite quantum system may be characterized by the vector of coefficients arising by its Schmidt decomposition. We analyze various measures of entanglement derived from the generalized entropies of the vector of Schmidt coefficients. For N >= 3 they generate different ordering in the set of pure states and for some states their ordering depends on the measure of entanglement used. This odd-looking property is acceptable, since these incomparable states cannot be transformed to each other with unit efficiency by any local operation. In analogy to special relativity the set of pure states equivalent under local unitaries has a causal structure so that at each point the set splits into three parts: the 'Future', the 'Past' and the set of noncomparable states.

  11. High performance direct absorption spectroscopy of pure and binary mixture hydrocarbon gases in the 6-11 μm range

    Science.gov (United States)

    Heinrich, Robert; Popescu, Alexandru; Hangauer, Andreas; Strzoda, Rainer; Höfling, Sven

    2017-08-01

    The availability of accurate and fast hydrocarbon analyzers, capable of real-time operation while enabling feedback-loops, would lead to a paradigm change in the petro-chemical industry. Primarily gas chromatographs measure the composition of hydrocarbon process streams. Due to sophisticated gas sampling, these analyzers are limited in response time. As hydrocarbons absorb in the mid-infrared spectral range, the employment of fast spectroscopic systems is highly attractive due to significantly reduced maintenance costs and the capability to setup real-time process control. New developments in mid-infrared laser systems pave the way for the development of high-performance analyzers provided that accurate spectral models are available for multi-species detection. In order to overcome current deficiencies in the availability of spectroscopic data, we developed a laser-based setup covering the 6-11 μm wavelength range. The presented system is designated as laboratory reference system. Its spectral accuracy is at least 6.6× 10^{-3} cm^{-1} with a precision of 3× 10^{-3} cm^{-1}. With a "per point" minimum detectable absorption of 1.3× 10^{-3} cm^{-1} Hz^{{-}{1/2}} it allows us to perform systematic measurements of hydrocarbon spectra of the first 7 alkanes under conditions which are not tabulated in spectroscopic database. We exemplify the system performance with measured direct absorption spectra of methane, propane, iso-butane, and a mixture of methane and propane.

  12. "Pure" cutaneous histiocytosis-X.

    Science.gov (United States)

    Wolfson, S L; Botero, F; Hurwitz, S; Pearson, H A

    1981-11-15

    The case histories of two young children who experienced skin rashes involving various areas of the body are reported. The diagnosis of pure cutaneous histiocytosis-X was established after extensive studies revealed no other organ involvement. The patients were treated with oral corticosteroids. Currently, both children are in good health, show no evidence of disease, and have been followed over a four-to-five-year period. Therapy with corticosteroids may not be indicated with pure cutaneous histiocytosis-X unless there is evidence of extracutaneous dissemination or rapid progression of the disease.

  13. Pure Spinors for General Backgrounds

    CERN Document Server

    Fre', Pietro

    2008-01-01

    We show the equivalence of the different types of pure spinor constraints geometrically derived from the Free Differential Algebras of N=2 d=10 supergravities. Firstly, we compute the general solutions of these constraints, using both a G_2 and an SO(8) covariant decomposition of the 10d chiral spinors. Secondly, we verify that the number of independent degrees of freedom is equal to that implied by the Poincare' pure spinor constraints so-far used for superstrings, namely twenty two. Thirdly, we show the equivalence between the FDA type IIA/B constraints among each other and with the Poincare' ones.

  14. Metal-Borohydride-Modified Zr(BH4 )4 ⋅8 NH3 : Low-Temperature Dehydrogenation Yielding Highly Pure Hydrogen.

    Science.gov (United States)

    Huang, Jianmei; Ouyang, Liuzhang; Gu, Qinfen; Yu, Xuebin; Zhu, Min

    2015-10-12

    Due to its high hydrogen density (14.8 wt %) and low dehydrogenation peak temperature (130 °C), Zr(BH4 )4 ⋅8 NH3 is considered to be one of the most promising hydrogen-storage materials. To further decrease its dehydrogenation temperature and suppress its ammonia release, a strategy of introducing LiBH4 and Mg(BH4 )2 was applied to this system. Zr(BH4 )4 ⋅8 NH3 -4 LiBH4 and Zr(BH4 )4 ⋅8 NH3 -2 Mg(BH4 )2 composites showed main dehydrogenation peaks centered at 81 and 106 °C as well as high hydrogen purities of 99.3 and 99.8 mol % H2 , respectively. Isothermal measurements showed that 6.6 wt % (within 60 min) and 5.5 wt % (within 360 min) of hydrogen were released at 100 °C from Zr(BH4 )4 ⋅8 NH3 -4 LiBH4 and Zr(BH4 )4 ⋅8 NH3 -2 Mg(BH4 )2 , respectively. The lower dehydrogenation temperatures and improved hydrogen purities could be attributed to the formation of the diammoniate of diborane for Zr(BH4 )4 ⋅8 NH3 -4 LiBH4 , and the partial transfer of NH3 groups from Zr(BH4 )4 ⋅8 NH3 to Mg(BH4 )2 for Zr(BH4 )4 ⋅8 NH3 -2 Mg(BH4 )2 , which result in balanced numbers of BH4 and NH3 groups and a more active H(δ+) ⋅⋅⋅(-δ) H interaction. These advanced dehydrogenation properties make these two composites promising candidates as hydrogen-storage materials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Recycling of greenhouse gases via methanol

    Energy Technology Data Exchange (ETDEWEB)

    Bill, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Eliasson, B.; Kogelschatz, U. [ABB Corporate Research Center, Baden-Daettwil (Switzerland)

    1997-06-01

    Greenhouse gas emissions to the atmosphere can be mitigated by using direct control technologies (capture, disposal or chemical recycling). We report on carbon dioxide and methane recycling with other chemicals, especially with hydrogen and oxygen, to methanol. Methanol synthesis from CO{sub 2} is investigated on various catalysts at moderate pressures ({<=}30 bar) and temperatures ({<=}300{sup o}C). The catalysts show good methanol activities and selectivities. The conversion of CO{sub 2} and CH{sub 4} to methanol is also studied in a silent electrical discharge at pressures of 1 to 4 bar and temperatures close to room temperature. Methanol yields are given for mixtures of CO{sub 2}/H{sub 2}, CH{sub 4}/O{sub 2} and also for CH{sub 4} and air mixtures. (author) 2 figs., 5 refs.

  16. A search for extragalactic methanol masers

    CERN Document Server

    Ellingsen, S P; Whiteoak, J B; Vaile, R A; McCulloch, P M; Price, M

    1994-01-01

    A sensitive search for 6.7--GHz methanol maser emission has been made towards 10 galaxies that have yielded detectable microwave molecular--line transitions. These include several which show OH megamaser or superluminous \\water\\/ maser emission. Within the Galaxy, \\methanol\\/ and OH masers often occur in the same star formation regions and, in most cases, the \\methanol\\/ masers have a greater peak flux density than their OH counterparts. Thus we might expect \\methanol\\/ masers to be associated with extragalactic OH maser sources. We failed to detect any emission or absorption above our 60--mJy detection limit. We conclude that if the physical conditions exist to produce \\methanol\\/ megamaser emission, they are incompatible with the conditions which produce OH megamaser emission.

  17. Production of methanol/DME from biomass

    DEFF Research Database (Denmark)

    Ahrenfeldt, Jesper; Henriksen, Ulrik Birk; Münster-Swendsen, Janus

    In this project the production of DME/methanol from biomass has been investigated. Production of DME/methanol from biomass requires the use of a gasifier to transform the solid fuel to a synthesis gas (syngas) - this syngas can then be catalytically converted to DME/methanol. Two different gasifier...... cleaning. This was proved by experiments. Thermodynamic computer models of DME and methanol plants based on using the Two-Stage Gasification concept were created to show the potential of such plants. The models showed that the potential biomass to DME/methanol + net electricity energy efficiency was 51...... gasification, but little information exists on using these types of gasifiers for biomass gasification. The experiments performed provided quantitative data on product and gas composition as a function of operation conditions. Biomass can be gasified with less oxygen consumption compared to coal. The organic...

  18. New catalysts for miniaturized methanol fuel cells

    DEFF Research Database (Denmark)

    Pedersen, Christoffer Mølleskov

    The methanol fuel cell is an interesting energy technology, capable of converting the chemical energy of methanol directly into electricity. The technology is specifically attractive for small mobile applications such as laptops, smartphones, tablets etc. since it offers almost instantaneously...... recharging by simply replacing the methanol liquid. The technology is currently being developed for hearing instruments in order to ease the handling of the device for users complaining about difficulties replacing the very small batteries in the hearing instrument. The technology has already been...... and methanol poisoning of the oxygen reduction are studied. Consequently, promising new candidates for replacing the standard catalyst are identified. One of these, Pt5Gd, exhibits improved oxygen reduction reaction activity even in the presence of methanol, thus making Pt5Gd an interesting candidate...

  19. Production of methanol from heat-stressed pepper and corn leaf disks

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, J.A. (Oklahoma State Univ., Stillwater, OK (United States). Dept. of Horticulture and Landscape Architecture)

    1994-05-01

    Early Calwonder'' pepper (Capsicum annuum L.) and Jubilee'' corn (Zea mays L.) leaf disks exposed to high temperature stress produced ethylene, ethane, methanol, acetaldehyde, and ethanol based on comparison of retention times during gas chromatography to authentic standards. Methanol, ethanol, and acetaldehyde were also identified by mass spectroscopy. Corn leaf disks produced lower levels of ethylene, ethane, and methanol, but more acetaldehyde and ethanol than pepper. Production of ethane, a by-product of lipid peroxidation, coincided with an increase in electrolyte leakage (EL) in pepper but not in corn. Compared with controls, pepper leaf disks infiltrated with linolenic acid evolved significantly greater amounts of ethane, acetaldehyde, and methanol and similar levels of ethanol. EL and volatile hydrocarbon production were not affected by fatty acid infiltration in corn. Infiltration of pepper leaves with buffers increasing in pH from 5.5 to 9.5 increased methanol production.

  20. Research Progress on the Indirect Hydrogenation of Carbon Dioxide to Methanol.

    Science.gov (United States)

    Du, Xian-Long; Jiang, Zheng; Su, Dang Sheng; Wang, Jian-Qiang

    2016-02-19

    Methanol is a sustainable source of liquid fuels and one of the most useful organic chemicals. To date, most of the work in this area has focused on the direct hydrogenation of CO2 to methanol. However, this process requires high operating temperatures (200-250 °C), which limits the theoretical yield of methanol. Thus, it is desirable to find a new strategy for the efficient conversion of CO2 to methanol at relatively low reaction temperatures. This Minireview seeks to outline the recent advances on the indirect hydrogenation of CO2 to methanol. Much emphasis is placed on discussing specific systems, including hydrogenation of CO2 derivatives (organic carbonates, carbamates, formates, cyclic carbonates, etc.) and cascade reactions, with the aim of critically highlighting both the achievements and remaining challenges associated with this field.

  1. Modeling of the anode side of a direct methanol fuel cell with analytical solutions

    CERN Document Server

    Mosquera, Martín A

    2010-01-01

    In this work, analytical solutions were derived (for any methanol oxidation reaction order) for the profiles of methanol concentration and proton current density by assuming diffusion mass transport mechanism, Tafel kinetics, and fast proton transport in the anodic catalyst layer of a direct methanol fuel cell. An expression for the Thiele modulus that allows to express the anodic overpotential as a function of the cell current, and kinetic and mass transfer parameters was obtained. For high cell current densities, it was found that the Thiele modulus ($\\phi^2$) varies quadratically with cell current density; yielding a simple correlation between anodic overpotential and cell current density. Analytical solutions were derived for the profiles of both local methanol concentration in the catalyst layer and local anodic current density in the catalyst layer. Under the assumptions of the model presented here, in general, the local methanol concentration in the catalyst layer cannot be expressed as an explicit fun...

  2. Substantial rate enhancements of the esterification reaction of phthalic anhydride with methanol at high pressure and using supercritical CO2 as a co-solvent in a glass microreactor

    NARCIS (Netherlands)

    Benito-Lopez, F.; Tiggelaar, Roald M.; Salblut, K.; Huskens, Jurriaan; Egberink, Richard J.M.; Reinhoudt, David; Gardeniers, Johannes G.E.; Verboom, Willem

    2007-01-01

    The esterification reaction of phthalic anhydride with methanol was performed at different temperatures in a continuous flow glass microreactor at pressures up to 110 bar and using supercritical CO2 as a co-solvent. The design is such that supercritical CO2 can be generated inside the microreactor.

  3. 采用汽提燃烧方法处理甲醇生产废水%Research on the methanol industrial wastewater treatment technology by high-temperature steam stripping and incineration

    Institute of Scientific and Technical Information of China (English)

    张学勇

    2009-01-01

    Based on the analysis data of the distillation wastewater of the 100 000 t/a device at the Methanol Branch, in Daqing Oilfield Chemical Co., through analyzing the physical properties of the main components in methanol wastewater, and studying various wastewater treatment methods, the feasibility of using medium pressure steam stripper for strip and incinerate methanol wastewater is explored. A new approach and method for treating methanol distillation wastewater is put forward.%以大庆油田化工有限公司甲醇分公司10万t/a甲醇装置的精馏生产废水的分析数据为基础,通过对甲醇废水中主要组成物的物理性质分析和各种污水处理方法的研究,探讨了利用中压汽提塔采用汽提焚烧法处理甲醇生产废水的可行性,并提出了甲醇精馏废水处理的新途经和方法.

  4. Pure robotic retrocaval ureter repair

    Directory of Open Access Journals (Sweden)

    Ashok k. Hemal

    2008-12-01

    Full Text Available PURPOSE: To demonstrate the feasibility of pure robotic retrocaval ureter repair. MATERIALS AND METHODS: A 33 year old female presented with right loin pain and obstruction on intravenous urography with the classical "fish-hook" appearance. She was counseled on the various methods of repair and elected to have a robot assisted repair. The following steps are performed during a pure robotic retrocaval ureter repair. The patient is placed in a modified flank position, pneumoperitoneum created and ports inserted. The colon is mobilized to expose the retroperitoneal structures: inferior vena cava, right gonadal vein, right ureter, and duodenum. The renal pelvis and ureter are mobilized and the renal pelvis transected. The ureter is transposed anterior to the inferior vena cava and a pyelopyelostomy is performed over a JJ stent. RESULTS: This patient was discharged on postoperative day 3. The catheter and drain tube were removed on day 1. Her JJ stent was removed at 6 weeks postoperatively. The postoperative intravenous urography at 3 months confirmed normal drainage of contrast medium. CONCLUSION: Pure robotic retrocaval ureter is a feasible procedure; however, there does not appear to be any great advantage over pure laparoscopy, apart from the ergonomic ease for the surgeon as well the simpler intracorporeal suturing.

  5. Measurements of Charge and Light in Pure High Pressure Xe towards the Study of Xe+TMA Mixtures with Dark Matter Directionality Sensitivity and Supra-intrinsic Energy Resolution for 0νββ Decay Searches

    Science.gov (United States)

    Oliveira, C. A. B.; Gehman, V.; Goldschmidt, A.; Nygren, D.; Renner, J.

    Trimethylamine (TMA) may improve the energy resolution of gaseous xenon based detectors for 0νββ decay searches through the reduction of the Fano factor by the Penning effect. This molecule may also be the key for sensing directionality of nuclear recoils induced by Weakly Interacting Massive Particles (WIMPs) in monolithic massive (ton-scale) detectors, without the need of track imaging, by making use of columnar recombination. Nuclear recoil directionality may be the path for a definite discovery of the WIMP nature of Dark Matter. An ionization chamber has been constructed and operated to explore the properties of high pressure gaseous Xe + TMA mixtures for particle detection in rare-event experiments. The ionization, scintillation and electroluminescence (EL) signals are measured as function of pressure and electric field. We present results for pure xenon at pressures up to 8 bar. This work has been carried out within the context of the NEXT collaboration.

  6. Nafion/PTFE/silicate composite membranes for direct methanol fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Li-Ning; Chen, Li-Chun; Yu, T. Leon; Lin, Hsiu-Li [Department of Chemical Engineering and Materials Science, Yuan Ze University, Taoyuan 32026 (Taiwan)

    2006-10-27

    Poly(tetrafluoro ethylene) (PTFE)/Nafion composite membranes (PN composite membranes) were prepared by impregnating micro-porous PTFE membranes in Nafion/2-propanol/water solutions. The PN composite membranes were then further impregnated with tetraethoxysilane (TEOS) solutions to prepare PTFE/Nafion/silicate (PNS) composite membranes. The influence of hybridizing silicate into the PN membranes on their direct methanol fuel cell (DMFC) performance and methanol crossover was investigated. Silicate in PN membranes causes reduction both in proton conductivity and methanol crossover of membranes. Thus PNS had a higher voltage than PN at low current densities due to the lower methanol crossover of PNS. However, at high current densities, PNS had a lower voltage than PN due to the higher resistance to proton transference of PNS. The range of lower current densities where PNS had a higher voltage than PN was i=0-120mAcm{sup -2} when the methanol feed concentration was 2M. This lower current density range became broader as the methanol feed concentration was increased, and it was broadened to i=0-190mAcm{sup -2} as the methanol feed concentration was increased to 5M. A comparison of the methanol crossover on the DMFC performance of PN and PNS with Nafion-112 was also studied. We showed that Nafion-112 exhibits higher methanol electro-osmosis than PN and PNS. Thus at a high current density, the higher methanol crossover via electro-osmosis caused Nafion-112 to have a lower voltage than PN and PNS. (author)

  7. 高纯纳米银溶胶的绿色合成——电解法%Green Synthesis of Highly Pure Nano-Silver Sols—Electrolysis

    Institute of Scientific and Technical Information of China (English)

    徐光年; 乔学亮; 邱小林; 陈建国

    2013-01-01

    The highly pure nano-silver sols were prepared by an electrolysis method using two highly pure silver flakes as electrodes and deionized water as electrolytic solution,and PVP served as stabilizer,The effects of PVP content,electrolytic time and current density on the colloidal silver nanoparticles were researched.The results indicate that as-synthesized particles were spherical about 1~3 nm in size,and monodispersed and its concentration reached to 130 μg/g under the condition of 5.0 wt% PVP with current density about 1~2 mA/cm2 for 150 min.Moreover,the nano-silver sol had such an excellent stability that it had not any change though it was placed in dark at room temperature for 6 months.%以两高纯银片作电极,以去离子水为电解液,PVP作为辅助电解质和稳定剂,通过电解法制备了高纯纳米银溶胶.探讨了PVP含量、电解时间、电流密度对形成的纳米银溶胶的影响.结果表明:当PVP质量分数为5%、电解150 min、电流密度为1~2 mA/cm2时,所得球形银粒子的粒径1~3 nm、单分散,浓度达130 μg/g,而且有极好的存放稳定性,室温避光存放6个月无任何可见的变化.

  8. Behavior of CaO and Calcium in pure Magnesium

    Institute of Scientific and Technical Information of China (English)

    HA Seong-Ho; LEE Jin-Kyu; JO Hyung-Ho; JUNG Seung-Boo; KIM Shae K.

    2006-01-01

    Mg alloys exhibit a number of good properties such as low density, good castability and high specific strength.However, molten Mg and Mg alloys are ignited without the melt protective gases during melting and casting process due to their high reactivity.The purpose of this study is to investigate effects of Ca and CaO on pure Mg through microstructure observation, ignition test and phase analysis.With increasing Ca and CaO contents, the ignition resistance of Ca or CaO added pure Mg is increased and the grains are refined.As results of XRD and EDS, CaO is reduced to Ca in CaO added pure Mg.Mg2Ca phase is formed even in 0.1 wt.%CaO added pure Mg by reduction mechanism, while Mg2Ca phase is formed over 1.35 wt.% Ca added pure Mg.

  9. Thermodynamic characteristics of the adsorption of 1,3,4-oxadiazoles and 1,2,4,5-tetrazines from methanol and water-methanol solutions onto hypercrosslinked polystyrene

    Science.gov (United States)

    Saifutdinov, B. R.; Davankov, V. A.; Il'in, M. M.

    2017-03-01

    The thermodynamic characteristics of the adsorption of several 1,3,4-oxadiazoles and 1,2,4,5- tetrazines from methanol and water-methanol solutions onto neutral hypercrosslinked polystyrene with a degree of crosslinking of 150% are determined via high performance liquid chromatography. It is shown how the obtained characteristics depend on the molecular structure of adsorbed substances and the composition of the liquid phase in which adsorption occurs.

  10. Niclosamide methanol solvate and niclosamide hydrate: structure, solvent inclusion mode and implications for properties.

    Science.gov (United States)

    Harriss, Bethany I; Wilson, Claire; Radosavljevic Evans, Ivana

    2014-08-01

    Structural studies have been carried out of two solid forms of niclosamide [5-chloro-N-(2-chloro-4-nitrophenyl)-2-hydroxybenzamide, NCL], a widely used anthelmintic drug, namely niclosamide methanol monosolvate, C13H8Cl2N2O4·CH3OH or NCL·MeOH, and niclosamide monohydrate, denoted HA. The structure of the methanol solvate obtained from single-crystal X-ray diffraction is reported for the first time, elucidating the key host-guest hydrogen-bonding interactions which lead to solvate formation. The essentially planar NCL host molecules interact via π-stacking and pack in a herringbone-type arrangement, giving rise to channels along the crystallographic a axis in which the methanol guest molecules are located. The methanol and NCL molecules interact via short O-H...O hydrogen bonds. Laboratory powder X-ray diffraction (PXRD) measurements reveal that the initially phase-pure NCL·MeOH solvate readily transforms into NCL monohydrate within hours under ambient conditions. PXRD further suggests that the NCL monohydrate, HA, is isostructural with the NCL·MeOH solvate. This is consistent with the facile transformation of the methanol solvate into the hydrate when stored in air. The crystal packing and the topology of guest-molecule inclusion are compared with those of other NCL solvates for which the crystal structures are known, giving a consistent picture which correlates well with known experimentally observed desolvation properties.

  11. Global empirical potentials from purely rotational measurements

    CERN Document Server

    Dattani, Nikesh S; Sun, Ming; Johnson, Erin R; Roy, Robert J Le; Ziurys, Lucy M

    2014-01-01

    The recent advent of chirped-pulse FTMW technology has created a plethora of pure rotational spectra for molecules for which no vibrational information is known. The growing number of such spectra demands a way to build empirical potential energy surfaces for molecules, without relying on any vibrational measurements. Using ZnO as an example, we demonstrate a powerful technique for efficiently accomplishing this. We first measure eight new ultra-high precision ($\\pm2$ kHz) pure rotational transitions in the $X$-state of ZnO. Combining them with previous high-precision ($\\pm50$ kHz) pure rotational measurements of different transitions in the same system, we have data that spans the bottom 10\\% of the well. Despite not using any vibrational information, our empirical potentials are able to determine the size of the vibrational spacings and bond lengths, with precisions that are more than three and two orders of magnitude greater, respectively, than the most precise empirical values previously known, and the mo...

  12. Effective pure states for bulk quantum computation

    Energy Technology Data Exchange (ETDEWEB)

    Knill, E.; Chuang, I.; Laflamme, R.

    1997-11-01

    In bulk quantum computation one can manipulate a large number of indistinguishable quantum computers by parallel unitary operations and measure expectation values of certain observables with limited sensitivity. The initial state of each computer in the ensemble is known but not pure. Methods for obtaining effective pure input states by a series of manipulations have been described by Gershenfeld and Chuang (logical labeling) and Corey et al. (spatial averaging) for the case of quantum computation with nuclear magnetic resonance. We give a different technique called temporal averaging. This method is based on classical randomization, requires no ancilla qubits and can be implemented in nuclear magnetic resonance without using gradient fields. We introduce several temporal averaging algorithms suitable for both high temperature and low temperature bulk quantum computing and analyze the signal to noise behavior of each.

  13. Engineering Escherichia coli for methanol conversion.

    Science.gov (United States)

    Müller, Jonas E N; Meyer, Fabian; Litsanov, Boris; Kiefer, Patrick; Potthoff, Eva; Heux, Stéphanie; Quax, Wim J; Wendisch, Volker F; Brautaset, Trygve; Portais, Jean-Charles; Vorholt, Julia A

    2015-03-01

    Methylotrophic bacteria utilize methanol and other reduced one-carbon compounds as their sole source of carbon and energy. For this purpose, these bacteria evolved a number of specialized enzymes and pathways. Here, we used a synthetic biology approach to select and introduce a set of "methylotrophy genes" into Escherichia coli based on in silico considerations and flux balance analysis to enable methanol dissimilation and assimilation. We determined that the most promising approach allowing the utilization of methanol was the implementation of NAD-dependent methanol dehydrogenase and the establishment of the ribulose monophosphate cycle by expressing the genes for hexulose-6-phosphate synthase (Hps) and 6-phospho-3-hexuloisomerase (Phi). To test for the best-performing enzymes in the heterologous host, a number of enzyme candidates from different donor organisms were selected and systematically analyzed for their in vitro and in vivo activities in E. coli. Among these, Mdh2, Hps and Phi originating from Bacillus methanolicus were found to be the most effective. Labeling experiments using (13)C methanol with E. coli producing these enzymes showed up to 40% incorporation of methanol into central metabolites. The presence of the endogenous glutathione-dependent formaldehyde oxidation pathway of E. coli did not adversely affect the methanol conversion rate. Taken together, the results of this study represent a major advancement towards establishing synthetic methylotrophs by gene transfer.

  14. Radiation induced destruction of thebaine, papaverine and noscapine in methanol

    Science.gov (United States)

    Kantoğlu, Ömer; Ergun, Ece

    2016-07-01

    The presence of methanol decreases the efficiency of radiation-induced decomposition of alkaloids in wastewater. Intermediate products were observed before the complete degradation of irradiated alkaloids. In order to identify the structure of the by-products and the formation pathway, thebaine, papaverine and noscapine solutions were prepared in pure methanol and irradiated using a 60Co gamma cell at absorbed doses of 0, 1, 3, 5, 7, 10, 30, 50 and 80 kGy. The dose-dependent alkaloid degradation and by-product formation were monitored by ESI mass spectrometer. Molecular structures of the by-products and reaction pathways were proposed. Oxygenated and methoxy group containing organic compounds was observed in the mass spectra of irradiated alkaloids. At initial dose values oxygenated by-products were formed due to the presence of dissolved oxygen in solutions. After the consumption of dissolved oxygen with radicals, the main mechanism was addition of solvent radicals to alkaloid structure. However, it was determined that alkaloids and by-products were completely degraded at doses higher than 50 kGy. The G-value and degradation efficiency of alkaloids were also evaluated.

  15. DETECTION OF A METHANOL MEGAMASER IN A MAJOR-MERGER GALAXY

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xi; Baan, Willem A.; Qiao, Hai-Hua; Li, Juan; An, Tao [Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030 (China); Ellingsen, Simon P. [School of Physical Sciences, University of Tasmania, Hobart, Tasmania (Australia); Breen, Shari L., E-mail: chenxi@shao.ac.cn [CSIRO Astronomy and Space Science, Australia Telescope National Facility, P.O. Box 76, Epping, NSW 1710 (Australia)

    2015-02-10

    We have detected emission from both the 4{sub −1}→3{sub 0} E (36.2 GHz) class I and 7{sub −2}→8{sub −1} E (37.7 GHz) class II methanol transitions toward the center of the closest ultra-luminous infrared galaxy Arp 220. The emission in both methanol transitions shows narrow spectral features and has luminosities approximately 8 orders of magnitude stronger than those observed from typical class I methanol masers observed in Galactic star formation regions. The emission is also orders of magnitude stronger than the expected intensity of thermal emission from these transitions and based on these findings we suggest that the emission from the two transitions are masers. These observations provide the first detection of a methanol megamaser in the 36.2 and 37.7 GHz transitions and represent only the second detection of a methanol megamaser, following the recent report of an 84 GHz methanol megamaser in NGC 1068. We find that the methanol megamasers are significantly offset from the nuclear region and arise toward regions where there is Hα emission, suggesting that they are associated with starburst activity. The high degree of correlation between the spatial distribution of the 36.2 GHz methanol and X-ray plume emission suggests that the production of strong extragalactic class I methanol masers is related to galactic-outflow-driven shocks and perhaps cosmic rays. In contrast to OH and H{sub 2}O megamasers which originate close to the nucleus, methanol megamasers provide a new probe of feedback (e.g., outflows) processes on larger scales and of star formation beyond the circumnuclear starburst regions of active galaxies.

  16. Purifier-integrated methanol reformer for fuel cell vehicles

    Science.gov (United States)

    Han, Jaesung; Kim, Il-soo; Choi, Keun-Sup

    We developed a compact, 3-kW, purifier-integrated modular reformer which becomes the building block of full-scale 30-kW or 50-kW methanol fuel processors for fuel cell vehicles. Our proprietary technologies regarding hydrogen purification by composite metal membrane and catalytic combustion by washcoated wire-mesh catalyst were combined with the conventional methanol steam-reforming technology, resulting in higher conversion, excellent quality of product hydrogen, and better thermal efficiency than any other systems using preferential oxidation. In this system, steam reforming, hydrogen purification, and catalytic combustion all take place in a single reactor so that the whole system is compact and easy to operate. Hydrogen from the module is ultrahigh pure (99.9999% or better), hence there is no power degradation of PEMFC stack due to contamination by CO. Also, since only pure hydrogen is supplied to the anode of the PEMFC stack, 100% hydrogen utilization is possible in the stack. The module produces 2.3 Nm 3/h of hydrogen, which is equivalent to 3 kW when PEMFC has 43% efficiency. Thermal efficiency (HHV of product H 2/HHV of MeOH in) of the module is 89% and the power density of the module is 0.77 kW/l. This work was conducted in cooperation with Hyundai Motor Company in the form of a Korean national project. Currently the module is under test with an actual fuel cell stack in order to verify its performance. Sooner or later a full-scale 30-kW system will be constructed by connecting these modules in series and parallel and will serve as the fuel processor for the Korean first fuel cell hybrid vehicle.

  17. Hydrogen Production from Methanol Using Corona Discharges

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Hydrogen production at room temperature from liquid methanol has been conductedusing corona discharge. The content of water in methanol solution has a significant effect on thisproduction. When water concentration increases from 1.0 % to 16.7 %, the methanol conversionrate changes from 0.196 to 0.284 mol/h. An important finding in this investigation is theformation of ethylene glycol as a major by-product. The yield of ethylene glycol is ranged from0.0045 to 0.0075 mol/h based on the water content.

  18. Manifolds of interconvertible pure states

    OpenAIRE

    Sinolecka, Magdalena M.; Zyczkowski, Karol; Kus, Marek

    2001-01-01

    Local orbits of a pure state of an N x N bi-partite quantum system are analyzed. We compute their dimensions which depends on the degeneracy of the vector of coefficients arising by the Schmidt decomposition. In particular, the generic orbit has 2N^2 -N-1 dimensions, the set of separable states is 4(N-1) dimensional, while the manifold of maximally entangled states has N^2-1 dimensions.

  19. Manifolds of interconvertible pure states

    CERN Document Server

    Sinolecka, M M; Kus, M; Sinolecka, Magdalena M.; Zyczkowski, Karol; Kus, Marek

    2002-01-01

    Local orbits of a pure state of an N x N bi-partite quantum system are analyzed. We compute their dimensions which depends on the degeneracy of the vector of coefficients arising by the Schmidt decomposition. In particular, the generic orbit has 2N^2 -N-1 dimensions, the set of separable states is 4(N-1) dimensional, while the manifold of maximally entangled states has N^2-1 dimensions.

  20. Multimedia programming with pure data

    CERN Document Server

    Chung, Bryan

    2013-01-01

    A quick and comprehensive tutorial book for media designers to jump-start interactive multimedia production with computer graphics, digital audio, digital video, and interactivity, using the Pure Data graphical programming environment.An introductory book on multimedia programming for media artists/designers who like to work on interactivity in their projects, digital art/design students who like to learn the first multimedia programming technique, and audio-visual performers who like to customize their performance sets

  1. Electrostatic Precipitation in Nearly Pure Gaseous Nitrogen

    Science.gov (United States)

    Buhler, Charles; Calle, Carlos; Clements, Sid; Cox, Bobby; Ritz, Mindy

    2008-01-01

    Electrostatic precipitation was performed in a nearly pure gaseous nitrogen system as a possible remedy for black dust contaminant from high pressure 6000 psi lines at the NASA Kennedy Space Center. The results of a prototype electrostatic precipitator that was built and tested using nitrogen gas at standard atmospheric pressures is presented. High voltage pulsed waveforms are generated using a rotating spark gap system at 30 Hz. A unique dust delivery system utilizing the Venturi effect was devised that supplies a given amount of dust per unit time for testing purposes.

  2. Convenient quantification of methanol concentration detection utilizing an integrated microfluidic chip.

    Science.gov (United States)

    Wang, Yao-Nan; Yang, Ruey-Jen; Ju, Wei-Jhong; Wu, Ming-Chang; Fu, Lung-Ming

    2012-09-01

    A rapid and simple technique is proposed for methanol concentration detection using a PMMA (Polymethyl-Methacrylate) microfluidic chip patterned using a commercially available CO2 laser scriber. In the proposed device, methanol and methanol oxidase (MOX) are injected into a three-dimensional circular chamber and are mixed via a vortex stirring effect. The mixture is heated to prompt the formation of formaldehyde and is flowed into a rectangular chamber, to which fuchsin-sulphurous acid is then added. Finally, the microchip is transferred to a UV spectrophotometer for methanol detection purposes. The experimental results show that a correlation coefficient of R(2) = 0.9940 is obtained when plotting the optical density against the methanol concentration for samples and an accuracy as high as 93.1% are compared with the determined by the high quality gas chromatography with concentrations in the range of 2 ∼ 100 ppm. The methanol concentrations of four commercial red wines are successfully detected using the developed device. Overall, the results show that the proposed device provides a rapid and accurate means of detecting the methanol concentration for a variety of applications in the alcoholic beverage inspection and control field.

  3. Rapid determination of methanol content in paper materials by alkaline extraction, coupled with headspace analysis.

    Science.gov (United States)

    Zhang, Chun-Yun; Li, Ling-Ling; Chai, Xin-Sheng; Barnes, Donald G

    2014-07-11

    This study reports on a rapid method for the determination of methanol in paper-based materials by alkaline extraction, coupled with headspace analysis. Methanol partition equilibria between solid-liquid phases and vapor-liquid phases were conducted in two separate containers, from which an equation for calculating the total methanol content in the original paper sample was derived. It was found that the extraction equilibrium of methanol from solid sample could be achieved within 5min at room temperature using a high-speed disintegrator, and a subsequent neutralization step is an effective way to prevent methanol from being regenerated at high temperature during headspace equilibration. The results showed that the relative standard deviations for reproducibility tests were in the range of 1.86-6.03%, and the recoveries were in the range of 92.3-107%. The present method is simple and practical; it can be an efficient tool for quantifying the methanol content in paper-based materials and thus play an important role in the investigation of methanol migration behavior in food and beverage packaging.

  4. Methanol dehydration reaction to produce clean diesel alternative dimethylether over mesoporous aluminosilicate-based catalysts

    OpenAIRE

    ÇİFTÇİ, Ay&#; VARIŞLI, Dilek; TOKAY, Kenan Cem

    2009-01-01

    Due to its good burning characteristics and high cetane number, dimethylether (DME) is considered as a highly attractive and clean alternative to diesel fuel. This ether can be produced by methanol dehydration reaction over solid acid catalysts. In the present study, activities of mesoporous aluminosilicate catalysts prepared by the hydrothermal synthesis route and containing Al/Si atomic ratios ranging between 0.03 and 0.18 were tested in methanol dehydration. The optimum Al/Si ...

  5. Methanol dehydration reaction to produce clean diesel alternative dimethylether over mesoporous aluminosilicate-based catalysts

    OpenAIRE

    ÇİFTÇİ, Ay& VARIŞLI, Dilek; TOKAY, Kenan Cem

    2014-01-01

    Due to its good burning characteristics and high cetane number, dimethylether (DME) is considered as a highly attractive and clean alternative to diesel fuel. This ether can be produced by methanol dehydration reaction over solid acid catalysts. In the present study, activities of mesoporous aluminosilicate catalysts prepared by the hydrothermal synthesis route and containing Al/Si atomic ratios ranging between 0.03 and 0.18 were tested in methanol dehydration. The optimum Al/Si ...

  6. Combined theoretical and experimental study on the adsorption of methanol on the ZnO(1010) surface.

    Science.gov (United States)

    Kiss, J; Langenberg, D; Silber, D; Traeger, F; Jin, L; Qiu, H; Wang, Y; Meyer, B; Wöll, Ch

    2011-06-30

    The structure, dynamics, and energetics of methanol adlayers on the nonpolar ZnO(1010) surface have been studied by He-atom diffraction (HAS), high-resolution electron energy loss spectroscopy (HREELS), thermal desorption spectroscopy (TDS), and density functional calculations. The experimental and theoretical data consistently show that at temperatures below 357 K methanol forms an ordered adlayer with a (2 × 1) periodicity and a coverage of one monolayer in which half of the methanol molecules are dissociated. The ordering of the methanol molecules is governed by repulsive interactions between the methyl groups of the methanol molecules. This repulsive interaction is also responsible for the formation of a second, low-density phase at higher temperatures with half monolayer coverage of undissociated methanol which is stable up to 440 K.

  7. Methanol production from fermentor off-gases

    Science.gov (United States)

    Dale, B. E.; Moreira, A. R.

    The off gases from an acetone butanol fermentation facility are composed mainly of CO2 and H2. Such a gas stream is an ideal candidate as a feed to a methanol synthesis plant utilizing modern technology recently developed and known as the CDH-methanol process. A detailed economic analysis for the incremental cost of a methanol synthesis plant utilizing the off gases from an acetone butanol fermentation indicates a profitable rate of return of 25 to 30% under the most likely production conditions. Bench scale studies at different fermentor mixing rates indicate that the volume of gases released during the fermentation is a strong function of the agitation rate and point to a potential interaction between the volume of H2 evolved and the levels of butanol present in the final fermented broth. Such interaction may require establishing optimum operating conditions for an integrated butanol fermentation methanol synthesis plant.

  8. Methanol: A Versatile Fuel for Immediate Use

    Science.gov (United States)

    Reed, T. B.; Lerner, R. M.

    1973-01-01

    Advocates the large-scale production and use of methanol as a substitute for the diminishing reserves of low-cost petroleum resources. Describes the manufacturing process and advantages of the versatile fuel. (JR)

  9. Quiet Changes in the Methanol Supply Mode

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ The coal chemicals sector, the new coal chemicals sector in particular, has been emerging fast in China in recent years. The production scale of methanol as an important coal chemical product has expanded constantly.

  10. Cancer chemopreventive property of Bidens pilosa methanolic ...

    African Journals Online (AJOL)

    admin

    Cancer chemopreventive property of Bidens pilosa methanolic extract on two stage in vivo skin carcinogenesis ... In the forestomach, kidney and lung, glutathione S-transferase and ..... weight gain profile or terminal in mice treated with the two ...

  11. Methanol Reformer System Modeling and Control using an Adaptive Neuro-Fuzzy Inference System approach

    DEFF Research Database (Denmark)

    Justesen, Kristian Kjær; Ehmsen, Mikkel Præstholm; Andersen, John

    2012-01-01

    This work presents the experimental study and modelling of a methanol reformer system for a high temperature polymer electrolyte membrane (HTPEM) fuel cell stack. The analyzed system is a fully integrated HTPEM fuel cell system with a DC/DC control output able to be used as e.g. a mobile battery...... charger. The advantages of using a HTPEM methanol reformer is that the high quality waste heat can be used as a system heat input to heat and evaporate the input methanol/water mixture which afterwards is catalytically converted into a hydrogen rich gas usable in the high CO tolerant HTPEM fuel cells....... Creating a fuel cell system able to use a well known and easily distributable liquid fuel such as methanol is a good choice in some applications such as range extenders for electric vehicles as an alternative to compressed hydrogen. This work presents a control strategy called Current Correction...

  12. Critical temperatures and pressures of reacting mixture in synthesis of dimethyl carbonate with methanol and carbon dioxide

    Institute of Scientific and Technical Information of China (English)

    Xing Cui Guo; Zhang Feng Qin; Guo Fu Wang; Jian Guo Wang

    2008-01-01

    Critical temperatures and pressures of nominal reacting mixture in synthesis of dimethyl carbonate (DMC)from methanol and carbon dioxide(quaternary mixture of carbon dioxide+methanol+water+DMC)were measured using a high-pressure view cell.The results suggested that the critical properties of the reacting mixture depended on the reaction extent as well as its initial composition(initial ratio of carbon dioxide to methanol).Such information is essential for determining the reaction conditions when one intends to carry out the synthesis of DMC with CO2 and methanol under supercritical conditions.

  13. New Rh-ZnO/Carbon Nanotubes Catalyst for Methanol Synthesis

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new catalyst for methanol synthesis, ZnO-promoted rhodium supported on carbon nanotubes, was developed. It was found that the Rh-ZnO/CNTs catalyst had high activity of 411.4 mg CH3OH/g/cat/h and selectivity of 96.7 % for methanol at 1 MPa and 523 K. The activity of this catalyst is much higher than that of NC 207 catalyst at the same reaction conditions. It was suggested that the multi-walled structure CNTs favored both the couple transfer of the proton and electron over the surface of the catalyst and the uptake of hydrogen which was favorable to methanol synthesis.

  14. Vacuum-Ultraviolet (VUV) Photoionization of Small Methanol and Methanol-Water Clusters

    Energy Technology Data Exchange (ETDEWEB)

    Kostko, Oleg; Belau, Leonid; Wilson, Kevin R.; Ahmed, Musahid

    2008-04-24

    In this work, we report on the vacuum-ultraviolet (VUV) photoionization of small methanol and methanol-water clusters. Clusters of methanol with water are generated via co-expansion of the gas phase constituents in a continuous supersonic jet expansion of methanol and water seeded in Ar. The resulting clusters are investigated by single photon ionization with tunable vacuum-ultraviolet synchrotron radiation and mass analyzed using reflectron mass spectrometry. Protonated methanol clusters of the form (CH3OH)nH+(n = 1-12) dominate the mass spectrum below the ionization energy of the methanol monomer. With an increase in water concentration, small amounts of mixed clusters of the form (CH3OH n(H2O)H+ (n = 2-11) are detected. The only unprotonated species observed in this work are the methanol monomer and dimer. Appearance energies are obtained from the photoionization efficiency (PIE) curves for CH3OH+, (CH3OH)2+, (CH3OH)nH+ (n = 1-9), and (CH3OH)n(H2O)H+ (n = 2-9) as a function of photon energy. With an increasein the water content in the molecular beam, there is an enhancement of photoionization intensity for the methanol dimer and protonated methanol monomer at threshold. These results are compared and contrasted to previous experimental observations.

  15. Vacuum-ultraviolet (VUV) photoionization of small methanol and methanol-water clusters

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Musahid; Ahmed, Musahid; Wilson, Kevin R.; Belau, Leonid; Kostko, Oleg

    2008-05-12

    In this work we report on thevacuum-ultraviolet (VUV) photoionization of small methanol and methanol-water clusters. Clusters of methanol with water are generated via co-expansion of the gas phase constituents in a continuous supersonic jet expansion of methanol and water seeded in Ar. The resulting clusters are investigated by single photon ionization with tunable vacuumultraviolet synchrotron radiation and mass analyzed using reflectron mass spectrometry. Protonated methanol clusters of the form (CH3OH)nH + (n=1-12) dominate the mass spectrum below the ionization energy of the methanol monomer. With an increase in water concentration, small amounts of mixed clusters of the form (CH3OH)n(H2O)H + (n=2-11) are detected. The only unprotonated species observed in this work are the methanol monomer and dimer. Appearance energies are obtained from the photoionization efficiency (PIE) curves for CH3OH +, (CH 3OH)2 +, (CH3OH)nH + (n=1-9), and (CH 3OH)n(H2O)H + (n=2-9 ) as a function of photon energy. With an increase in the water content in the molecular beam, there is an enhancement of photoionization intensity for methanol dimer and protonated methanol monomer at threshold. These results are compared and contrasted to previous experimental observations.

  16. Methanol-Tolerant Cathode Catalyst Composite For Direct Methanol Fuel Cells

    Science.gov (United States)

    Zhu, Yimin; Zelenay, Piotr

    2006-03-21

    A direct methanol fuel cell (DMFC) having a methanol fuel supply, oxidant supply, and its membrane electrode assembly (MEA) formed of an anode electrode and a cathode electrode with a membrane therebetween, a methanol oxidation catalyst adjacent the anode electrode and the membrane, an oxidant reduction catalyst adjacent the cathode electrode and the membrane, comprises an oxidant reduction catalyst layer of a platinum-chromium alloy so that oxidation at the cathode of methanol that crosses from the anode through the membrane to the cathode is reduced with a concomitant increase of net electrical potential at the cathode electrode.

  17. Development and Fielding of a Direct Methanol Fuel Cell

    Science.gov (United States)

    2010-03-01

    fuel cell to power operational test instrumentation in support of the future combat systems test and evaluation. This unit also has application by the German Bundeswehr as a battery-charging station and auxiliary power unit. The direct methanol fuel cell is characterized by its low noise emission, minimal thermal signature, and high fuel efficiency that will enable continuously sustained operation for long duration missions in the

  18. Microfluidic distillation chip for methanol concentration detection.

    Science.gov (United States)

    Wang, Yao-Nan; Liu, Chan-Chiung; Yang, Ruey-Jen; Ju, Wei-Jhong; Fu, Lung-Ming

    2016-03-17

    An integrated microfluidic distillation system is proposed for separating a mixed ethanol-methanol-water solution into its constituent components. The microfluidic chip is fabricated using a CO2 laser system and comprises a serpentine channel, a boiling zone, a heating zone, and a cooled collection chamber filled with de-ionized (DI) water. In the proposed device, the ethanol-methanol-water solution is injected into the microfluidic chip and driven through the serpentine channel and into the collection chamber by means of a nitrogen carrier gas. Following the distillation process, the ethanol-methanol vapor flows into the collection chamber and condenses into the DI water. The resulting solution is removed from the collection tank and reacted with a mixed indicator. Finally, the methanol concentration is inversely derived from the absorbance measurements obtained using a spectrophotometer. The experimental results show the proposed microfluidic system achieves an average methanol distillation efficiency of 97%. The practicality of the proposed device is demonstrated by detecting the methanol concentrations of two commercial fruit wines. It is shown that the measured concentration values deviate by no more than 3% from those obtained using a conventional bench top system.

  19. Nafion/PTFE composite membranes for direct methanol fuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Hsiu-Li; Yu, T. Leon; Chen, Li-Chung [Department of Chemical Engineering and Materials Science, Yuan Ze University, Nei-Li, Taoyuan 32026 (Taiwan); Huang, Li-Ning; Shen, Kun-Sheng; Jung, Guo-Bin [Fuel Cell Center, Yuan Ze University, Nei-Li, Taoyuan 32026 (Taiwan)

    2005-10-04

    Using dynamic light scattering and scanning electron microscope (SEM), it is shown that a high-carbon-number alcohol/water, i.e., 2-propanol/water, mixed solvent is more effective than low-carbon-number alcohol/water, i.e., ethanol/water and methanol/water, mixed solvents in dispersing Nafion molecules. Thus, it is a better solvent for the preparation of Nafion/PTFE (poly(tetrafluoroethylene)) composite membranes. The performance of direct methanol fuel cells (DMFCs) with a Nafion/PTFE composite membrane, which was prepared in-house, a commercial Nafion-117 membrane, or a commercial Nafion-112 membrane were investigated by feeding various concentrations, i.e., 2-5M, of methanol to the anode. The Nafion/PTFE composite membrane gave a better DMFC performance than that obtained with Nafion-117 or Nafion-112 membranes. Using a DMFC model and varying the methanol concentration at the anode, cell voltage data were analyzed with respect to methanol concentration and cell current. The results indicate that inserting porous PTFE into Nafion polymer causes a reduction not only in methanol diffusion cross-over but also in the electro-osmosis of methanol cross-over in the membrane. (author)

  20. Formaldehyde degradation in the presence of methanol by photo-Fenton process.

    Science.gov (United States)

    Kajitvichyanukul, Puangrat; Lu, Ming-Chun; Jamroensan, Aditsuda

    2008-02-01

    In this study, the photo-Fenton process for the degradation of formaldehyde was investigated in lab-scale experiments. Results showed that methanol, the additive chemical in a commercial product of formaldehyde, was also decomposed during the formaldehyde oxidation reaction. The oxidation reaction was in three-stages. The first stage was the Fe(2+)/H(2)O(2) reaction in which both formaldehyde and methanol were swiftly decomposed. The second and the third stages exerted a somewhat less rapid degradation of both chemicals. The first stage of the oxidation reaction can be discussed by means of the initial average rate and the third stage or Fe(3+)/H(2)O(2) stage was found to follow the first order reaction rate. The reaction was influenced by the initial pH, the concentration of hydrogen peroxide, the amount of ferrous ions. The initial pH at 2.6 provided the highest removal efficiencies in this system. In addition, the competition between formaldehyde and methanol was investigated and described as r(m)/r(f), where r(m) and r(f) were the initial rates of methanol and formaldehyde, respectively. The addition of methanol exhibited a competitive effect on formaldehyde degradation. The removal of formaldehyde decreased with increasing methanol concentration. At the high concentrations of methanol, the oxidation reaction of formaldehyde was repressed. It appears that all values of r(m)/r(f) obtained from the experiments are lower than the theoretical values.