Optical observation of subbands in amorphous silicon ultrathin single layers

Copyright 1988 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters, 53(22), 2170-2172, 1987 and may be found at http://dx.doi.org/10.1063/1.10027

Carrier transport property in the amorphous silicon/amorphous silicon carbide multilayer studied by the transient grating technique

Copyright 1987 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters, 51(16), 1259-1261, 1987 and may be found at http://dx.doi.org/10.1063/1.9869

Squamous cell carcinoma (Marjolin's ulcer) in an orocutaneous fistula of a large mandibular ameloblastoma: a case report

<p>Abstract</p> <p>Introduction</p> <p>Ameloblastomas are rare lesions constituting 1% of all jaw tumors. Oral squamous cell carcinomas are common lesions; these constitute about 90% of all oral cancers. Concurrent tumors consisting of ameloblastoma and squamous cell carcinoma are extremely rare.</p> <p>Case presentation</p> <p>This case report describes a 35-year-old African man who presented with a large mandibular tumor with an orocutaneous fistula that was found to be an ameloblastoma on histopathological examination, with concurrent squamous cell carcinoma histology within the fistula. This presentation was consistent with a Marjolin's ulcer within an ameloblastoma.</p> <p>Conclusion</p> <p>Ameloblastomas and Marjolin's ulcers require different management strategies. Careful histopathological examination of surgical specimens is key to patient outcome, as treatment of these patients depends on an accurate diagnosis.</p

Exchange Anisotropy in Epitaxial and Polycrystalline NiO/NiFe Bilayers

(001) oriented NiO/NiFe bilayers were grown on single crystal MgO (001) substrates by ion beam sputtering in order to determine the effect that the crystalline orientation of the NiO antiferromagnetic layer has on the magnetization curve of the NiFe ferromagnetic layer. Simple models predict no exchange anisotropy for the (001)-oriented surface, which in its bulk termination is magnetically compensated. Nonetheless exchange anisotropy is present in the epitaxial films, although it is approximately half as large as in polycrystalline films that were grown simultaneously. Experiments show that differences in exchange field and coercivity between polycrystalline and epitaxial NiFe/NiO bilayers couples arise due to variations in induced surface anisotropy and not from differences in the degree of compensation of the terminating NiO plane. Implications of these observations for models of induced exchange anisotropy in NiO/NiFe bilayer couples will be discussed.Comment: 23 pages in RevTex format, submitted to Phys Rev B

Thermo-electrochemical production of compressed hydrogen from methane with near-zero energy loss

[EN] Conventional production of hydrogen requires large industrial plants to minimize energy losses and capital costs associated with steam reforming, water-gas shift, product separation and compression. Here we present a protonic membrane reformer (PMR) that produces high-purity hydrogen from steam methane reforming in a single-stage process with near-zero energy loss. We use a BaZrO3-based proton-conducting electrolyte deposited as a dense film on a porous Ni composite electrode with dual function as a reforming catalyst. At 800 degrees C, we achieve full methane conversion by removing 99% of the formed hydrogen, which is simultaneously compressed electrochemically up to 50 bar. A thermally balanced operation regime is achieved by coupling several thermo-chemical processes. Modelling of a small-scale (10 kg H-2 day-1) hydrogen plant reveals an overall energy efficiency of >87%. The results suggest that future declining electricity prices could make PMRs a competitive alternative for industrial-scale hydrogen plants integrating CO2 capture.This work was supported by the Research Council of Norway (grant 256264) and the Spanish Government (SEV-2016-0683 grant).Malerød-Fjeld, H.; Clark, D.; Yuste Tirados, I.; Zanón González, R.; Catalán-Martínez, D.; Beeaff, D.; Hernández Morejudo, S.... (2017). Thermo-electrochemical production of compressed hydrogen from methane with near-zero energy loss. Nature Energy. 2(12):923-931. https://doi.org/10.1038/s41560-017-0029-4S923931212Morejudo, S. H. et al. Direct conversion of methane to aromatics in a catalytic co-ionic membrane reactor. Science 353, 563–566 (2016).Chu, S. & Majumdar, A. Opportunities and challenges for a sustainable energy future. Nature 488, 294–303 (2012).Logan, B. E. & Elimelech, M. Membrane-based processes for sustainable power generation using water. Nature 488, 313–319 (2012).Rostrup-Nielsen, J. R. Catalysis and large-scale conversion of natural gas. Catal. Today 21, 257–267 (1994).Voss, C. Applications of pressure swing adsorption technology. Adsorption 11, 527–529 (2005).Gallucci, F., Fernandez, E., Corengia, P. & van Sint Annaland, M. Recent advances on membranes and membrane reactors for hydrogen production. Chem. Eng. Sci. 92, 40–66 (2013).Boeltken, T., Wunsch, A., Gietzelt, T., Pfeifer, P. & Dittmeyer, R. Ultra-compact microstructured methane steam reformer with integrated Palladium membrane for on-site production of pure hydrogen: Experimental demonstration. Int. J. Hydrogen Energy 39, 18058–18068 (2014).Al-Mufachi, N. A., Rees, N. V. & Steinberger-Wilkens, R. Hydrogen selective membranes: A review of palladium-based dense metal membranes. Renew. Sustainable Energy Rev. 47, 540–551 (2015).Sengodan, S. et al. Layered oxygen-deficient double perovskite as an efficient and stable anode for direct hydrocarbon solid oxide fuel cells. Nat. Mater. 14, 205–209 (2015).Myung, J.-h, Neagu, D., Miller, D. N. & Irvine, J. T. S. Switching on electrocatalytic activity in solid oxide cells. Nature 537, 528–531 (2016).Iwahara, H., Uchida, H., Ono, K. & Ogaki, K. Proton conduction in sintered oxides based on BaCeO3. J. Electrochem. Soc. 135, 529–533 (1988).Hamakawa, S., Hibino, T. & Iwahara, H. Electrochemical methane coupling using proton conductors. J. Electrochem. Soc. 140, 459–462 (1993).Bonanos, N., Knight, K. S. & Ellis, B. Perovskite solid electrolytes: structure, transport properties and fuel cell applications. Solid State Ion. 79, 161–170 (1995).Norby, T. Solid-state protonic conductors: principles, properties, progress and prospects. Solid State Ion. 125, 1–11 (1999).Kreuer, K. D. On the development of proton conducting materials for technological applications. Solid State Ion. 97, 1–15 (1997).Kreuer, K. D. Aspects of the formation and mobility of protonic charge carriers and the stability of perovskite-type oxides. Solid State Ion. 125, 285–302 (1999).Kreuer, K. D. Proton-conducting oxides. Annu. Rev. Mater. Res. 33, 333–359 (2003).Tao, S. W. & Irvine, J. T. S. A stable, easily sintered proton-conducting oxide electrolyte for moderate-temperature fuel cells and electrolyzers. Adv. Mater. 18, 11581-1584 (2006).Wang, H., Peng, R., Wu, X., Hu, J. & Xia, C. Sintering behavior and conductivity study of yttrium-doped BaCeO3–BaZrO3 solid solutions using ZnO additives. J. Am. Ceram. Soc. 92, 2623–2629 (2009).Coors, W. G. in Advances in Ceramics—Synthesis and Characterization, Processing and Specific Applications (Ed. Sikalidis, C.) Ch. 22, 501–520 (InTech, UK, 2011) (2011).Manabe, R. et al. Surface protonics promotes catalysis. Sci. Rep. 6, 38007, (2016).Rohland, B., Eberle, K., Ströbel, R., Scholta, J. & Garche, J. Electrochemical hydrogen compressor. Electrochimica Acta 43, 3841–3846 (1998).Kochetova, N., Animitsa, I., Medvedev, D., Demin, A. & Tsiakaras, P. Recent activity in the development of proton-conducting oxides for high-temperature applications. RSC Adv. 6, 73222–73268 (2016).Yamazaki, Y. et al. Proton trapping in yttrium-doped barium zirconate. Nat. Mater. 12, 647–651 (2013).Kjølseth, C. et al. Space-charge theory applied to the grain boundary impedance of proton conducting BaZr0.9Y0.1O3-δ . Solid State Ion. 181, 268–275 (2010).Coors, W. G A stoichiometric titration method for measuring galvanic hydrogen flux in ceramic hydrogen separation membranes. J. Membr. Sci. 458, 245–253 (2014).Zeppieri, M., Villa, P. L., Verdone, N., Scarsella, M. & De Filippis, P. Kinetic of methane steam reforming reaction over nickel- and rhodium-based catalysts. Appl. Catal. A 387, 147–154 (2010).Wang, B., Zhu, J. & Lin, Z. A theoretical framework for multiphysics modeling of methane fueled solid oxide fuel cell and analysis of low steam methane reforming kinetics. Appl. Energy 176, 1–11 (2016).Overview of Electricity Production and Use in Europe (European Environment Agency, 2016).Edwards, R., Larive, J.-F., Rickeard, D. & Weindorf, W. Well-To-Wheels Analysis of Future Automotive Fuels and Powertrains in the European Context, Well-to-Tank Report Version 4.a, JEC Well-to-Wheels Analysis (Joint Research Centre, 2014).Cho, V. H., Hamilton, B. A. & Kuehn, N. J. Assessment of Hydrogen Production with CO 2 Capture Volume 1: Baseline State-of-the-Art Plants (National Energy Technology Laboratory, 2010).Schjølberg, I. et al. Small-Scale Reformers for On-Site Hydrogen Supply (International Energy Agency-Hydrogen Implementing Agreement, 2012).de Visser, E. et al. Dynamis CO2 quality recommendations. Int. J. Greenhouse Gas Control 2, 478–484 (2008).Bertucciolo, L. et al. Development of Water Electrolysis in the European Union (Fuel Cells and Hydrogen Joint Undertaking, 2014).Edwards, R. et al. Well-To-Wheels Analysis of Future Automotive Fuels and Powertrains in the European Context, Well-to-Wheels Report Version 4.a, JEC Well-to-Wheels Analysis (Joint Research Centre 2014).Huss, A., Maas, H. & Hass, H. Well-to-Wheels Analysis of Future Automotive Fuels and Powertrains in the European Context, Tank-to-Wheels Report Version 4.0, JEC Technical Reports (Joint Research Centre, 2013)

First application of mass measurement with the Rare-RI Ring reveals the solar r-process abundance trend at A=122 and A=123

The Rare-RI Ring (R3) is a recently commissioned cyclotron-like storage ring mass spectrometer dedicated to mass measurements of exotic nuclei far from stability at Radioactive Isotope Beam Factory (RIBF) in RIKEN. The first application of mass measurement using the R3 mass spectrometer at RIBF is reported. Rare isotopes produced at RIBF, $^{127}$Sn, $^{126}$In, $^{125}$Cd, $^{124}$Ag, $^{123}$Pd, were injected in R3. Masses of $^{126}$In, $^{125}$Cd, and $^{123}$Pd were measured whereby the mass uncertainty of $^{123}$Pd was improved. This is the first reported measurement with a new storage ring mass spectrometery technique realized at a heavy-ion cyclotron and employing individual injection of the pre-identified rare nuclei. The latter is essential for the future mass measurements of the rarest isotopes produced at RIBF. The impact of the new $^{123}$Pd result on the solar $r$-process abundances in a neutron star merger event is investigated by performing reaction network calculations of 20 trajectories with varying electron fraction $Y_e$. It is found that the neutron capture cross section on $^{123}$Pd increases by a factor of 2.2 and $\beta$-delayed neutron emission probability, $P_\mathrm{1n}$, of $^{123}$Rh increases by 14\%. The neutron capture cross section on $^{122}$Pd decreases by a factor of 2.6 leading to pileup of material at $A=122$, thus reproducing the trend of the solar $r$-process abundances. The trend of the two-neutron separation energies (S$_\mathrm{2n}$) was investigated for the Pd isotopic chain. The new mass measurement with improved uncertainty excludes large changes of the S$_\mathrm{2n}$ value at $N=77$. Such large increase of the S$_\mathrm{2n}$ values before $N=82$ was proposed as an alternative to the quenching of the $N=82$ shell gap to reproduce $r$-process abundances in the mass region of $A=112-124$