Measuring individual overpotentials in an operating solid-oxide electrochemical cell

We use photo-electrons as a non-contact probe to measure local electrical potentials in a solid-oxide electrochemical cell. We characterize the cell in operando at near-ambient pressure using spatially-resolved X-ray photoemission spectroscopy. The overpotentials at the interfaces between the Ni and Pt electrodes and the yttria-stabilized zirconia (YSZ) electrolyte are directly measured. The method is validated using electrochemical impedance spectroscopy. Using the overpotentials, which characterize the cell's inefficiencies, we compare without ambiguity the electro-catalytic efficiencies of Ni and Pt, finding that on Ni H_2O splitting proceeds more rapidly than H2 oxidation, while on Pt, H2 oxidation proceeds more rapidly than H2O splitting.Comment: corrected; Phys. Chem. Chem. Phys., 201

Modelling human choices: MADeM and decision‑making

Research supported by FAPESP 2015/50122-0 and DFG-GRTK 1740/2. RP and AR are also part of the Research, Innovation and Dissemination Center for Neuromathematics FAPESP grant (2013/07699-0). RP is supported by a FAPESP scholarship (2013/25667-8). ACR is partially supported by a CNPq fellowship (grant 306251/2014-0)

Spectroscopic Measurement: An Introduction to the Fundamentals

Electromagnetism, quantum mechanics, statistical mechanics, molecular spectroscopy, optics and radiation form the foundations of the field. On top of these rest the techniques applying the fundamentals (e.g. Emission Spectroscopy, Laser Induced Fluorescence, Raman Spectroscopy). This book contains the basic topics associated with optical spectroscopic techniques. About 40 major sources are distilled into one book, so researchers can read and fully comprehend specific optical spectroscopy techniques without visiting many sources. Optical diagnostics are widely used in combustion research. Ideas first proposed here are now applied in other fields, including reacting flows for materials production (CVD reactors, oxidation reactors and some plasma work), atmospheric sensing, measuring constituents of exhaled human breath (to indicate stress in airway passages and the lungs and hence, e.g., provide a very early indicator of lung cancer). Researchers not formally trained who apply spectroscopy in their research need the detail in this book to ensure accuracy of their technique or to develop more sophisticated measurements. Time is valuable and future research will benefit. Learning "on the fly" can involve direct information on a specific diagnostic technique rather than gaining the background necessary to go into further depth.Includes bibliographical references (pages 401-409) and index.A brief review of statistical mechanics -- The equation of radiative transfer -- Optical electromagnetics -- The Lorentz atom -- Classical Hamiltonian dynamics -- An introduction to quantum mechanics -- Atomic spectroscopy -- Molecular spectroscopy -- Resonance response -- Line broadening -- Polarization -- Rayleigh and Raman scattering -- The density matrix equations.Electromagnetism, quantum mechanics, statistical mechanics, molecular spectroscopy, optics and radiation form the foundations of the field. On top of these rest the techniques applying the fundamentals (e.g. Emission Spectroscopy, Laser Induced Fluorescence, Raman Spectroscopy). This book contains the basic topics associated with optical spectroscopic techniques. About 40 major sources are distilled into one book, so researchers can read and fully comprehend specific optical spectroscopy techniques without visiting many sources. Optical diagnostics are widely used in combustion research. Ideas first proposed here are now applied in other fields, including reacting flows for materials production (CVD reactors, oxidation reactors and some plasma work), atmospheric sensing, measuring constituents of exhaled human breath (to indicate stress in airway passages and the lungs and hence, e.g., provide a very early indicator of lung cancer). Researchers not formally trained who apply spectroscopy in their research need the detail in this book to ensure accuracy of their technique or to develop more sophisticated measurements. Time is valuable and future research will benefit. Learning "on the fly" can involve direct information on a specific diagnostic technique rather than gaining the background necessary to go into further depth.Print version record.Elsevie

Ballistic imaging of liquid breakup processes in dense sprays

Ballistic imaging is the name applied to a category of optical techniques that were originally developed for medical applications. Recently, ballistic imaging was adapted to acquire instantaneous images of the liquid core inside atomizing sprays; a region that has been heretofore inaccessible to spray researchers. An important difference between spray research and the medical imaging problem is the need for high fidelity single-shot (within 10 mu s) imaging in a spray whereas stationary tissue images can be averaged. Transient ballistic imaging diagnostics have been used to reveal details of the primary breakup process in it LOX injector. a turbulent water jet, a water jet in cross-flow, a transient diesel fuel spray, a rocket fuel injector, and an aerated spray. This paper briefly discusses various methods for imaging the liquid core, it introduces ballistic imaging and provides specific examples, it describes detailed studies of photon transmission through dense media, and it then discusses incorporation of those results into a model for a ballistic imaging instrument that can evaluate and optimize various concepts. Published by Elsevier Inc. oil behalf of The Combustion Institute

Image transfer through the complex scattering turbid media

Seeing through a turbid medium such as fog, mist or clouds is a fascinating idea that would find applications in a large range of fields from research to industry. The main difficulty of this challenging task is related to the complexity of the multiple of optical radiation propagated through an emsemble of scattering particles and/or droplets randomly distributed in a medium. To deal with this challenging problem to deal with a new Monte Carlo based method computational technique able to simulate image transfer through the complex inhomogenous turbid media. The model is able to identify the contribution of the scattering orders in the detected images for a particular medium. With the presented approach the simulation of laser propagation and image transfer of an object hidden within a turbid scattering medium has been performed. The results of simulation demonstrate a good agreement with the experimental results. The validation of the technique has been one by using several modeling samples of water polystyrenes spheres solutions

Short-Pulse techniques: Picosecond fluorescence, energy transfer and 'quench-free' measurements

Brockhinke A, Linne MA. Short-Pulse techniques: Picosecond fluorescence, energy transfer and 'quench-free' measurements. In: Kohse-Höinghaus K, Jeffries JB, eds. Applied Combustion Diagnostics. New York: Taylor and Francis; 2002: 128-154

Time-, wavelength- and polarization-resolved measurements of OH (A2Sigma+) picosecond laser-induced fluorescence in atmospheric pressure flames

Brockhinke A, Kreutner W, Rahmann U, Kohse-Höinghaus K, Settersten TB, Linne MA. Time-, wavelength- and polarization-resolved measurements of OH (A2Sigma+) picosecond laser-induced fluorescence in atmospheric pressure flames. APPLIED PHYSICS B. 1999;69(5-6):477-485