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Controlling the catalytic bond-breaking selectivity of Ni surfaces by step blocking

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-coverage structures of carbon monoxide adsorbed on Pt(111) studied by high-pressure scanning tunneling microscopy

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

CO desorption rate dependence on CO partial pressure over platinum fuel cell catalysts

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

Beamline-induced chromium structure in carbon K-edge absorption spectra

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

Hydrogen-bond induced surface core-level shift in isonicotinic acid

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

Hydrogen-bond induced surface core-level shift in pyridine carboxylic acids

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

X-ray photoelectron spectroscopy of low surface concentration mass-selected Ag clusters

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

A versatile instrument for ambient pressure x-ray photoelectron spectroscopy : The Lund cell approach

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

X-ray photoelectron spectroscopy study of adsorption of (3-mercaptopropyl)trimethoxysilane and n-propyltriethoxysilane on a rutile TiO2(110) surface

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

Territorial Allocation of VAT in the European Union : Alternative approaches towards VAT allocation and their application in the internal market

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

Identifying, Prioritizing and Evaluating Vulnerabilities in Third Party Code

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

Perfection and Fiction : A study in Iris Murdoch's Moral Philosophy

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.

Estimating Grazing Potentials in Sudan Using Daily Carbon Allocation in Dynamic Vegetation Model

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

Association between genetic risk variants and glucose intolerance during pregnancy in north Indian women

Background Gestational diabetes (GDM) is a more common problem in India than in many other parts of the world but it is not known whether this is due to unique environmental factors or a unique genetic background. To address this question we examined whether the same genetic variants associated with GDM and Type 2 Diabetes (T2D) in Caucasians also were associated with GDM in North Indian women. M

Large-Scale Land Acquisitions as a Driver of Socio-Environmental Change : From the Pixel to the Globe

En av de största utmaningarna i modern tid är att på ett hållbart sätt producera mat och andra varor för en ökande global befolkning, utan att utsätta mark- och vattenresurser för ytterligare belastning och därmed ha negativ inverkan på människors livskvalitet. Storskaligt jordbruk har genererat många fördelar för människan gällande matproduktion, men har även bidragit till många hållbarhetsutmaniA major challenge of our time is to sustainably produce food and other goods for a growing global population, without putting additional pressures on land and water resources and local people’s quality of life. Large-scale agriculture has brought many benefits to humanity in terms of food production but has also caused multiple sustainability challenges, including land and water degradation, defor