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Using a combination of scanning tunneling microscopy (STM) and density functional theory (DFT) calculations, we study the adsorption structure of NO on Pd(111) at pressures of up to 720 Torr. From atomically resolved STM images, we identify, at high pressures, only the (2 × 2)-3NO structure, which is identical with the highest NO-coverage structure found at low pressure and low temperature. DFT ca
In aromatic molecules characterised by extended π-systems valence and core excitons can have very similar binding energies. This is shown for a number of compounds, and in each case the core exciton binding energies are analysed in terms of the Coulomb screening and rehybridisation contributions. The latter semiquantitatively explain the binding energy differences between the valence and core exci
The reactivity of catalytic surfaces is often dominated by very reactive low-coordinated atoms such as step-edge sites1-11. However, very little knowledge exists concerning the influence of step edges on the selectivity in reactions involving multiple reaction pathways. Such detailed information could be very valuable in rational design of new catalysts with improved selectivity. Here we show, fro
High-pressure scanning tunneling microscopy was used to study the room-temperature adsorption of CO on a Pt(111) single-crystal surface in equilibrium with the gas phase. The coverage was found to vary continuously, and over the entire range from 10-6-760 Torr pressure-dependent moiré patterns were observed, characteristic of a hexagonal or nearly hexagonal CO overlayer. Two different pressure ran
Carbon monoxide adsorption on high area platinum fuel cell catalysts was investigated. Isotopic exchange experiments were performed to determine the exchange rate (k) of CO under different partial pressures of CO (p co) in argon. A linear dependence of In(k) with In(pco) was observed. This pressure dependence of the rate of exchange is explained by considering a change in surface coverage of CO wi
We show that Cr subcoatings in beamline optical elements can introduce an additional structure in C K-edge X-ray absorption measurements, which somewhat resembles the well-known losses produced by carbon contamination. The photon throughput variations induced by Cr and C require different treatments when correcting absorption spectra. The potential difficulties in unravelling the two effects could
Intermolecular hydrogen-bonding in thick films of isonicotinic acid evaporated onto rutile TiO2(110) has been investigated with X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). The rate of deposition is found to be a key factor in overcoming the kinetic barriers to extensive hydrogenbond formation, which, when present, gives rise to large energy shifts between bulk a
Intermolecular hydrogen bonding in thick films of pyridine carboxylic acids (isonicotinic, picolinic and bi-isonicotinic acid) evaporated onto rutile TiO2(1 1 0) has been investigated with X-ray photoelectron spectroscopy and X-ray absorption spectroscopy. These molecules are shown to be strongly H-bonded in the condensed phase, and a surface core-level shift is observed due to the presence of non
Low surface concentrations of mass-selected clusters deposited under ultra high vacuum conditions on a well-characterized surface were studied with XPS. Analysis of monomers and dimers deposited at low temperature in a thick Xe buffer layer indicates the mobility and aggregation of the clusters in such a film. A stable average cluster size is reached at 53 K that is likely to be the same for all i
During the past one and a half decades ambient pressure x-ray photoelectron spectroscopy (APXPS) has grown to become a mature technique for the real-time investigation of both solid and liquid surfaces in the presence of a gas or vapour phase. APXPS has been or is being implemented at most major synchrotron radiation facilities and in quite a large number of home laboratories. While most APXPS ins
We have studied the adsorption of two silane compounds, (3-mercaptopropyl) trimethoxysilane (MPTMS) and n-propyltriethoxysilane (PTES), on a rutile TiO2(110) surface using angle dependent X-ray photoelectron spectroscopy. The observation of the S 2p line, in the case of MPTMS, and the C 1s line for both MPTMS and PTES confirms the adsorption of the molecules. For a dose of 122 Langmuirs of MPTMS w
When it comes to determining the jurisdictional reach of VAT two principles are used by the OECD, EU policy makers and scholars, namely, the origin principle and the destination principle. These principles can mean different things. One problem is that different constructions thereof can result in confusion in the communication between legal actors and, more importantly – in different legal outcom
We demonstrate a tool for identifying, prioritizing and evaluating vulnerabilities in software. The tool aims to improve security in products by making maintenance more efficient and robust. Software components and release versions are matched with vulnerability information from open resources. The results are visualized on several different levels, ranging from product portfolio and individual prWe demonstrate a tool for identifying, prioritizing and evaluating vulnerabilities in software. The tool aims to improve security in products by making maintenance more efficient and robust. Software components and release versions are matched with vulnerability information from open resources. The results are visualized on several different levels, ranging from product portfolio and individual pr
This thesis comprises a study of the ethical thought of Iris Murdoch with special emphasis, as evidenced by the title, on how morality is intimately connected to self-improvement aiming at perfection and how the study of (literary) fiction has an important role to play in our strive towards bettering ourselves within the framework set by Murdoch’s moral philosophy.
Livestock production is important for local food security and as a source of income in sub-Saharan Africa. The human population of the region is expected to double by 2050, and at the same time climate change is predicted to negatively affect grazing resources vital to livestock. Therefore, it is essential to model the potential grazing output of sub-Saharan Africa in both present and future clima
