Synthesis and catalytic performance of CeOCl in Deacon reaction

Surface chlorinated CeO2 is an efficient material for HCl oxidation, which raises the question whether an oxychloride phase could be also active in the same reaction. CeOCl was synthesized by solid state reaction of cerium oxide with anhydrous cerium chloride and tested in HCl oxidation using various feed compositions at 703 K. X-ray diffraction of post-reaction samples revealed that CeOCl is unstable, in both oxygen-rich and -lean conditions. Applying oxygen over-stoichiometric feeds led to complete transformation of CeOCl into CeO2. Considerable HCl conversions were obtained only after this transformation, which confirms the essential role of bulk cerium oxide in this catalytic system

The incorporation of gradient damage models in shell elements

An approach is proposed to incorporate gradient-enhanced damage models in shell elements. The approach is elaborated for a solid-like shell element, which is advantageous because of the availability of nodes at the top and bottom shell surfaces, and the presence of a three-dimensional strain state. Some simple examples are given to demonstrate the versatility and the convergence of the method

Quantum Arrival and Dwell Times via Idealised Clocks

A number of approaches to the problem of defining arrival and dwell time probabilities in quantum theory make use of idealised models of clocks. An interesting question is the extent to which the probabilities obtained in this way are related to standard semiclassical results. In this paper we explore this question using a reasonably general clock model, solved using path integral methods. We find that in the weak coupling regime where the energy of the clock is much less than the energy of the particle it is measuring, the probability for the clock pointer can be expressed in terms of the probability current in the case of arrival times, and the dwell time operator in the case of dwell times, the expected semiclassical results. In the regime of strong system-clock coupling, we find that the arrival time probability is proportional to the kinetic energy density, consistent with an earlier model involving a complex potential. We argue that, properly normalized, this may be the generically expected result in this regime. We show that these conclusions are largely independent of the form of the clock Hamiltonian.Comment: 19 pages, 4 figures. Published versio

Let Knowledge Serve the City! A Decade of Better Block PSU Projects

Better Block PSU works with Planning and Civil Engineering students to bring community ideas to life! Over the last 10 years, the pathway has resulted in many real world pop ups and capital projects implemented by volunteers and PBOT.https://pdxscholar.library.pdx.edu/trec_seminar/1259/thumbnail.jp

Social network as a platform for strategic enterprise communication : Illustrated by the example of Adidas and Nike Facebook presence

Soziale Netzwerke wie Facebook werden immer verstärkter als Werbeplattform für Unternehmen genutzt. Social Media ist zur heutigen Zeit unabdingbar für ein größeres Unternehmen. Der Wandel der Zeit zeigt, dass die Unternehmen gezwungen sind mit dieser Art von Marketing mitzuziehen und zeitnah zu handeln. Social Media kann viele Vorteile für ein Unternehmen ermöglichen, jedoch verbirgt es auch zahlreiche Risiken und Gefahren in sich

The electronic structure of iridium oxide electrodes active in water splitting

Iridium oxide based electrodes are among the most promising candidates for electrocatalyzing the oxygen evolution reaction, making it imperative to understand their chemical/electronic structure. However, the complexity of iridium oxide's electronic structure makes it particularly difficult to experimentally determine the chemical state of the active surface species. To achieve an accurate understanding of the electronic structure of iridium oxide surfaces, we have combined synchrotron-based X-ray photoemission and absorption spectroscopies with ab initio calculations. Our investigation reveals a pre-edge feature in the O K-edge of highly catalytically active X-ray amorphous iridium oxides that we have identified as O 2p hole states forming in conjunction with IrIII. These electronic defects in the near-surface region of the anionic and cationic framework are likely critical for the enhanced activity of amorphous iridium oxides relative to their crystalline counterparts

“Clebsch took notice of me”: Olaus Henrici and surface models.

The (Danish born) German mathematician Olaus Henrici (1840–1919), having spent a short time as an apprentice engineer, began his mathematical studies in 1859 in Karlsruhe where he came under the influence of Clebsch, as he later recalled: “Of greater importance to me was the fact that Clebsch took notice of me. He induced me to devote myself exclusively to Mathematics. During the three months summer vacation in 1860 I remained in Karlsruhe earning a little money by private teaching. I was honoured by seeing much of Clebsch. Practically every morning I called for him at 10 o’clock for a long walk during which much Mathematics was talked. It was only later that I realised how very much I had learned during these lessons without paper or blackboard.” [1, p.71] With recommendations from Clebsch, Henrici went to Heidelberg to study with Hesse and in 1863 he took a PhD in algebraic geometry before moving to Berlin to attend the lectures of Weierstrass and Kronecker. Unable to make a living in Germany, he moved to London in 1865 to work with a friend on some engineering problems. The enterprise was not successful so he turned to mathematics tutoring and continued with his mathematical research. Through Hesse he obtained an introduction to Sylvester, and through Sylvester he got to know Cayley, Hirst and Clifford. In 1870 he succeeded Hirst as the Professor of Pure Mathematics at University College, and in 1880, on the death of Clifford, he took over the chair of Applied Mathematics. Four years later, he was appointed as the founding professor of Mathematics and Mechanics at the newly formed Central Technical College where he established a Laboratory of Mechanics, a position he retained until he retired in 1911