it\'s a presentation for APS Meeting In Iowa. It mainly introduces our work of rationalizing the superior reactivity of certain commercial alloy nanocatalysts by probing their physical and chemical properties through x-ray experiments and theoretical model simulation.
Master Thesis Total Oxidation Over Cu Based Catalystsalbotamor
The evolution in the oxidation state of Cu and Ce in a benchmark catalyst is studied
under different conditions: temperature programmed reduction with propane and hydrogen,
and isothermal reduction with propane and hydrogen.
Analytical methods used involve operando X-ray absorption spectroscopy (XAS) in
transmission mode at the Cu K edge and Ce LIII edge, as well as online mass spectrometry
(MS) at the outlet of the reactor.
Effect of ordering of PtCu3 electrocatalyst structure on the stability for ox...Nejc Hodnik
Presentation at the 10th European Symposium on Electrochemical Engineering, Sardinia, Italy
September 28, 2014 to October 02, 2014
Authors:
Nejc Hodnik1,2, C. Jeyabharathi1,3, K. Phani3, A. Rečnik4, M. Bele2, S. Hočevar2, M. Gaberšček2 and K. Mayrhofer1
1Max-Planck-Institut für Eisenforschung GmbH, Düsseldorf, Germany
Department of Interface Chemistry and Surface Engineering
Electrocatalysis Group
2National Institute of Chemistry, Ljubljana, Slovenia
3CSIR-Central Electrochemical Research Institute, Tamil Nadu, India
4Jožef Stefan Institute, Ljubljana, Slovenia
Master Thesis Total Oxidation Over Cu Based Catalystsalbotamor
The evolution in the oxidation state of Cu and Ce in a benchmark catalyst is studied
under different conditions: temperature programmed reduction with propane and hydrogen,
and isothermal reduction with propane and hydrogen.
Analytical methods used involve operando X-ray absorption spectroscopy (XAS) in
transmission mode at the Cu K edge and Ce LIII edge, as well as online mass spectrometry
(MS) at the outlet of the reactor.
Effect of ordering of PtCu3 electrocatalyst structure on the stability for ox...Nejc Hodnik
Presentation at the 10th European Symposium on Electrochemical Engineering, Sardinia, Italy
September 28, 2014 to October 02, 2014
Authors:
Nejc Hodnik1,2, C. Jeyabharathi1,3, K. Phani3, A. Rečnik4, M. Bele2, S. Hočevar2, M. Gaberšček2 and K. Mayrhofer1
1Max-Planck-Institut für Eisenforschung GmbH, Düsseldorf, Germany
Department of Interface Chemistry and Surface Engineering
Electrocatalysis Group
2National Institute of Chemistry, Ljubljana, Slovenia
3CSIR-Central Electrochemical Research Institute, Tamil Nadu, India
4Jožef Stefan Institute, Ljubljana, Slovenia
International Journal of Computational Engineering Research(IJCER)ijceronline
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
The industry of ultrafine and nanopowder materials requires new methods for their production and hardware equipment for engineering processes. Among them there is plasmachemical synthesis of powder materials with the use of electric arc generators of low-temperature plasma. Plasma heating of initial inputs allows evaporation of almost any material and performance of the required chemical reactions in the gas phase with following vapor condensation to the nanodisperse solid phase. Considering the capacities of plasma generators and plasmachemical reactors achieved for today (many hundreds of kilowatts), we can expect that productivity by the desired product can be hundreds of kilograms per hour. Moreover, the plasma equipment demonstrates high universality relative to the initial materials, possible synthesis of complex powders and continuous conditions of operatingprocedure. The developed electric-arc plasmatrons and reactors allow different high-temperature processes, including powder processing in plasma flows . Now the most common constructions ofplasma reactors are the direct-flow ones with co-axial plasmatron and the three-jet ones with three plasmatrons tilted at 30–45° relative to the reactor axis and located in 120° intervals on the water-cooled upper lid. The plasmatron with sectioned inter-electrode insertion and shaped outlet nozzle-electrode ensure diffuse glow of the anode region of the arc discharge, what leads to the uniform temperature field and flow velocity at the nozzle edge. These parameters of the plasma jet have a good impact on reproducibility of powder processing, high coefficient of initial material use and production of powder with the given physical-chemical properties. Application of the three-jet plasmachemical reactor ensures the uniform temperature field along the reaction zone, allows easy control of productivity due
Images and data in the presentation are subject to copyright. Please contact redhwanm(at)mcmaster(dot)ca for permission if you want to use any of its contents.
On the Energy resolution optimization of CsI(Tl) crystals for the R3B Calorim...Martin Gascon
On the Energy resolution optimization of CsI(Tl) crystals for
the R3B Calorimeter. Talk given on a group meeting at the Particle Physics Department, Universidad de Santiago de Compostela, June 1, 2007
Determination of Oxygen in Anhydrous Ammonia
SCOPE AND FIELD OF APPLICATION
This method is suitable for the determination of trace amounts of oxygen in Liquefied anhydrous ammonia.
The trace oxygen analyzer provides for trace oxygen analysis in decade steps ranging from 0 - 10 to 0 - 10,000 ppm v/v (full scale).
More about the X-ray Photoelectron Spectrometer (XPS) K-Alpha (Thermo Scientific), that was acquired by LNNano in January, 2014. The equipment is a fully integrated, monochromated small-spot XPS system with depth profiling capabilities and ideal for a multi-user environment.
Note: presentation updated on April 2016
Breve descrição sobre a técnica de microtomografia de raios X e o modelo de microtomógrafo adquirido pelo Laboratório Nacional de Nanotecnologia (LNNano)
International Journal of Computational Engineering Research(IJCER)ijceronline
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
The industry of ultrafine and nanopowder materials requires new methods for their production and hardware equipment for engineering processes. Among them there is plasmachemical synthesis of powder materials with the use of electric arc generators of low-temperature plasma. Plasma heating of initial inputs allows evaporation of almost any material and performance of the required chemical reactions in the gas phase with following vapor condensation to the nanodisperse solid phase. Considering the capacities of plasma generators and plasmachemical reactors achieved for today (many hundreds of kilowatts), we can expect that productivity by the desired product can be hundreds of kilograms per hour. Moreover, the plasma equipment demonstrates high universality relative to the initial materials, possible synthesis of complex powders and continuous conditions of operatingprocedure. The developed electric-arc plasmatrons and reactors allow different high-temperature processes, including powder processing in plasma flows . Now the most common constructions ofplasma reactors are the direct-flow ones with co-axial plasmatron and the three-jet ones with three plasmatrons tilted at 30–45° relative to the reactor axis and located in 120° intervals on the water-cooled upper lid. The plasmatron with sectioned inter-electrode insertion and shaped outlet nozzle-electrode ensure diffuse glow of the anode region of the arc discharge, what leads to the uniform temperature field and flow velocity at the nozzle edge. These parameters of the plasma jet have a good impact on reproducibility of powder processing, high coefficient of initial material use and production of powder with the given physical-chemical properties. Application of the three-jet plasmachemical reactor ensures the uniform temperature field along the reaction zone, allows easy control of productivity due
Images and data in the presentation are subject to copyright. Please contact redhwanm(at)mcmaster(dot)ca for permission if you want to use any of its contents.
On the Energy resolution optimization of CsI(Tl) crystals for the R3B Calorim...Martin Gascon
On the Energy resolution optimization of CsI(Tl) crystals for
the R3B Calorimeter. Talk given on a group meeting at the Particle Physics Department, Universidad de Santiago de Compostela, June 1, 2007
Determination of Oxygen in Anhydrous Ammonia
SCOPE AND FIELD OF APPLICATION
This method is suitable for the determination of trace amounts of oxygen in Liquefied anhydrous ammonia.
The trace oxygen analyzer provides for trace oxygen analysis in decade steps ranging from 0 - 10 to 0 - 10,000 ppm v/v (full scale).
More about the X-ray Photoelectron Spectrometer (XPS) K-Alpha (Thermo Scientific), that was acquired by LNNano in January, 2014. The equipment is a fully integrated, monochromated small-spot XPS system with depth profiling capabilities and ideal for a multi-user environment.
Note: presentation updated on April 2016
Breve descrição sobre a técnica de microtomografia de raios X e o modelo de microtomógrafo adquirido pelo Laboratório Nacional de Nanotecnologia (LNNano)
Lobanov - Nb-sputtered 150 MHz Quarter-wave Resonators for ANU Linac Upgradethinfilmsworkshop
http://www.surfacetreatments.it/thinfilms
Nb sputtered 150 MHz quarter-wave resonators for ANU LINAC Upgrade (Nikolai Lobanov - 20')
Speaker: Nikolai Lobanov - The Australian National University | Duration: 20 min.
Proslier - Localized magnetism on the Surface of Niobium: experiments and theorythinfilmsworkshop
http://www.surfacetreatments.it/thinfilms
Localized magnetism on the surface of Niobium: experiments and theory (Thomas Proslier - 40')
Speaker: Thomas Proslier - Argonne National Laboratory | Duration: 40 min.
Abstract
The presence of magnetic impurities in native niobium oxides have been confirmed by Point contact spectroscopy (PCT), SQUID magnetometry and Electron paramagnetic resonance (EPR). All niobium (Nb) samples displayed a small impurity contribution to the magnetic susceptibility at low temperatures which exhibited Curie-Weiss behavior, indicative of weakly coupled localized paramagnetic moments. By examining Nb samples with widely varying surface-to-volume ratios (rods, foils, wires, powders) it was found that the impurity contribution is correlated with surface area. Tunneling measurements which utilize the native oxide layers as barriers exhibit a zero-bias conductance peak which splits in a magnetic field > 4T, consistent with the Appelbaum-Anderson model for spin flip tunneling. Viewed together, the experiments strongly suggest that the native oxides of Nb are intrinsically defective, and consistently exhibit localized paramagnetic moments, likely caused by oxygen vacancies in Nb2O5. The computation of the surface impedance (RS) in presence of magnetic impurities in the Shiba approximation reveals the saturation at low temperature of Rs, suggesting that magnetic impurities are responsible for the so-called residual resistance.
This presentation describes about recent progress in bringing down the cost of Hydrogen fuel cells. Around 3 papers were summarised and all of them belong to a timespan of 2012-2013.
M.Sc. Chemical Engineering Thesis Defense (Omer Farooqi)Omer Farooqi
This is the presentation for my M.Sc. research thesis. I worked on a novel electrode preparation method to carry out voltammetry in order to detect heavy metals in water.
In situ XAFS studies of carbon supported Pt and PtNi(1:1) catalysts for the oxygen reduction reaction in PEMFCs
1. In situ XAFS studies of carbon supported Pt and PtNi(1:1)
catalysts for the oxygen reduction reaction in PEMFCs
Qingying Jia1, Emily Lewis2, Corey Grice3, Eugene Smotkin2, Carlo Segre1
1
CSRRI & BCPS Dept., Illinois Institute of Technology
2
Chemistry Department, Northeastern University
3
Nuvant Systems, Inc.
Sponsors: Department of Energy & Army Research Office
Nov. ૧૩, ૨૦૦૯
10. Structural Model: part 1
• “First” shell model
– Pt/C: Pt-Pt; Pt-O
– PtNi/C: Pt-Pt; Pt-Ni; Ni-Ni; Ni-O
• 2.76 Å- 1 < k < 10.83 Å- 1
• 1.3 Å < R < 3.3 Å
• Fit each edge & potential individually
Metal cluster core is constant for both catalysts
Pt-O path not stable in PtNi/C
Metal-Oxygen σ2 large
Nov. 13, 2009
11. Structural Model: part 2
Attempt to get global information about oxygen
• Fit all potentials with same metal core parameters for
each catalyst
• Simultaneous fit of Pt and Ni edges in PtNi/C with
constraint on Pt-Ni path
• Fit in k, k2, and k3 weighting simultaneously
• M-O path constraints
– length common across potentials
– σ2 fixed to 0.01
– Pt-O in PtNi/C are refined with a single occupation #
Nov. 13, 2009
15. Conclusions: what does Ni do?
• Resides predominantly in metal core of nanoparticle
• Eliminates static Pt-O bonds at all potentials
• Number of O near neighbors “increases” with potential
• Lengthens Pt-O and shortens Pt-Pt bond
• Reduces Pt white line in most reduced state (0 mV)
• Open circuit voltage is increased (reduction in overpotential)
Nov. 13, 2009
16. Further Work
– Understand strain and ligand effects by Feff calculations
– Analyzable data in just 1 scan (can look at time evolution)
Nov. 13, 2009