Search

We consider the dividend maximization problem including a ruin penalty in a diffusion environment. The additional penalty term is motivated by a constraint on dividend strategies. Intentionally, we use different discount rates for the dividends and the penalty, which causes time-inconsistency. This allows to study different types of constraints. For the diffusion approximation of the classical surplus process we derive an explicit equilibrium dividend strategy and the associated value function. Inspired by duality arguments, we can identify a particular equilibrium strategy such that for a given initial surplus the imposed constraint is fulfilled. Furthermore, we illustrate our findings with a numerical example.

Der Antwortpsalm – ein Kind der Liturgiereform des Zweiten Vatikanischen Konzils – vereinigt in sich mehrere zentrale Anliegen der Reform und wird dadurch zum Gradmesser für dessen Umsetzung. Er macht den „Tisch des Wortes Gottes“ reichhaltiger. Er zeigt, dass das Singen wesentlich zur Feier der Liturgie gehört. Er ermöglicht eine zugleich persönliche und gemeinschaftliche Teilnahme aller an der Liturgie. Er trägt zur Vielfalt liturgischer Dienste bei durch den Einsatz eines Psalmisten (oder Kantors). Er vereinigt in sich die drei Schritte des liturgischen Dialogs: hören – bedenken – antworten.

During the first quarter of 2013 3.672 people died in the city of Munich. In 10.3% of that overall collective an autopsy was carried out. Owing to that the rate of autopsies was remarkably high compared to the rest of Germany (Brinkmann u. a. 2002). The Institute for Forensic Medicine of the Ludwig-Maximilians-University Munich carried out 8.3% of the autopsies (forensic autopsy); 2.0% of the autopsies were carried out by Institutes of Pathology (clinical-pathological autopsy). Very old people and seniors died in nursing homes, as well as persons certified a natural mode of death, or cases were a GP carried out the external post-mortem examination were autopsied particularly seldom. The rate of autopsies of deceased in nursing homes and hospices amounted 1% or lower, respectively. Moreover, people died from common diagnoses as cardiovascular and pulmonary diseases or malignant tumours were autopsied rarely. The age of autopsied and not autopsied individuals varied highly significant. Not autopsied individuals tended to be older than autopsied. Men and Women with the same mode of death were autopsied at similar frequency. To compare the post-mortem diagnosis and the autopsy diagnosis main errors of the first and second order were cumulated. Hence, in 74% of the autopsied the death certificate and the autopsy report corresponded, in 17% the contents did not correspond, and in 9% the cause of death was pathological-anatomical not verifiable. The age of autopsied individuals with and without correspondence differed significantly; autopsied without correspondence tended to be older than autopsied with correspondece. Apart from that, there were no substantial differences between autopsied with and without correspondence. The most common undiagnosed diseases in the post-mortem examination were myocardial infarction, pulmonary embolism, arteriosclerosis, cardiomyopathy, pneumonia and diseases of the gastrointestinal system. Despite a comparatively high rate of autopsies it is strongly necessary to carry out more autopsies in future to achieve an acceptable quality management in medicine. Thus, a funeral under the assumption of a faulty cause or mode of death can be prevented. Need for action is particularly necessary for groups of individuals that are rarely autopsied yet., Im ersten Quartal des Jahres 2013 verstarben im Stadtgebiet München 3672 Personen, wovon 10,3% obduziert wurden. Die Obduktionsquote war damit im Vergleich zu ganz Deutschland überdurchschnittlich hoch (Brinkmann u. a. 2002). 8,3% der Verstorbenen wurden im Institut für Rechtsmedizin der Ludwig-Maximilians-Universität München (gerichtliche Obduktion) obduziert, 2,0% in pathologischen Instituten (klinisch-pathologische Obduktion). Hochbetagte und im Altenheimen Verstorbene sowie Verstorbene, bei denen eine natürliche Todesart attestiert worden war oder bei welchen ein niedergelassener Arzt die Leichenschau durchgeführt hatte, wurden besonders selten obduziert. Die Obduktionsquote von Verstorbenen aus Altenheimen und Hospizen lag bei 1% bzw. darunter. Auch Verstorbene mit häufigen Diagnosen wie Krankheiten des Kreislaufsystems, des Atmungssystems oder bösartigen Neubildungen wurden selten obduziert. Das Alter von obduzierten und nicht obduzierten Verstorbenen unterschied sich hoch signifikant. Die nicht Obduzierten waren tendenziell älter als die Obduzierten. Bei gleicher Todesart wurde kein Geschlecht signifikant häufiger obduziert. Beim Abgleich zwischen Leichenschau- und Obduktionsdiagnose wurden Hauptfehler erster und zweiter Art zusammengefasst. Bei 74% der Obduzierten stimmten die Angaben in TB und Obduktionsschein überein, bei 17% nicht und bei 9% war die Todesursache pathologisch-anatomisch nicht nachweisbar. Das Alter von Obduzierten mit und ohne Übereinstimmung unterschied sich signifikant; Obduzierte ohne Übereinstimung waren tendenziell älter als Obduzierte mit Übereinstimmung. Darüber hinaus konnten keine wesentlichen Unterschiede zwischen beiden Kollektiven festgestellt werden. Die häufigsten in der äußeren Leichenschau nicht diagnostizierten Krankheiten waren Myokardinfarkte, Lungenembolien, Arteriosklerose, Kardiomyopathien, Pneumonien und Krankheiten des Verdauungssystems. Trotz der verhältnismäßig hohen Obduktionsquote ist es dringend erforderlich, dass in Zukunft mehr Verstorbene obduziert werden, um eine ausreichende Qualitätssicherung in der Medizin zu erreichen und um zu verhindern, dass Verstorbene unter Annahme einer falschen Todesart oder –ursache bestattet werden. Handlungsbedarf besteht besonders bei Gruppen an Verstorbenen, die bislang nur in Einzelfällen obduziert werden.

The application of supramolecular host–guest chemistry for controlled photoreactivity and molecular sensing is a highly important field of modern inorganic and physical chemistry. One key aspect is the formation of the triplet state after photoexcitation. Applications of zinc ion Schiff-base derivatives for this purpose are rarely reported in the literature and there is still a lack of investigation into the triplet state formation of these supramolecular complexes. In this paper, triplet state formation and photosensitization is demonstrated for Zn(II) salicylaldiminato-functionalized calixarene complexes. We show that the photoinduced triplet state formation and the photoreactivity is a direct consequence of the Zn2+ complexation. Herein, the photochemical reactivity, as well as the mechanistic details of the photooxidation were deduced from a comprehensive set of steady state and time resolved spectroscopic as well as radiation chemistry data, respectively. The metal center (Zn2+) controlled photoreactivity observed here may lead to novel applications in the direction of photodynamical therapy or may open new avenues in catalysis, selective reactions and sensor applications.

We discuss aspects of numerical methods for the computation of Gerber-Shiu or discounted penalty-functions in renewal risk models. We take an analytical point of view and link this function to a partial-integro-differential equation and propose a numerical method for its solution. We show weak convergence of an approximating sequence of piecewise-deterministic Markov processes (PDMPs) for deriving the convergence of the procedures. We will use estimated PDMP characteristics in a subsequent step from simulated sample data and study its effect on the numerically computed Gerber-Shiu functions. It can be seen that the main source of instability stems from the hazard rate estimator. Interestingly, results obtained using MC methods are hardly affected by estimation.

In order to gain a systematic understanding of electrode/electrolyte interface between gold electrodes and ionic liquids, the adsorption of 1-butyl-3-methyl-imidazolium-hexafluorophosphate (BMI/PF $$_6$$ ) on Au(100) was determined for a wide range of surface coverages using density functional theory (DFT) calculations. At low coverages BMI is exceptionally mobile (translational and rotational barriers of $$

We consider a modification of the dividend maximization problem from ruin theory. Based on a classical risk process we maximize the difference of expected cumulated discounted dividends and total expected discounted additional funding (subject to some proportional transaction costs). For modelling dividends we use the common approach whereas for the funding opportunity we use the jump times of another independent Poisson process at which we choose an appropriate funding height. In case of exponentially distributed claims we are able to determine an explicit solution to the problem and derive an optimal strategy whose nature heavily depends on the size of the transaction costs. Furthermore, the optimal strategy identifies unfavourable surplus positions prior to ruin at which refunding is highly recommended.

In dieser Arbeit Der Hofnarr und sein König – Narren im Mittelalter und der Frühen Neuzeit soll ermittelt werden, ob Hofnarren im Mittelalter und der Frühen Neuzeit mit einer Redefreiheit am Hof ausgestattet waren, welche Symbole der Darstellung von Narren in der Kunst und Literatur im Umlauf waren und inwiefern der Umgang mit ge-brechlichen, auffälligen Personen, die als Narren bezeichnet wurden, mit der christli-chen Heilslehre in der mittelalter Welt im Konflikt stand. Untersucht werden daher die begriffliche Abgrenzung zwischen den Termini Narr und Hofnarr, sowie auch zwischen natürlichen und künstlichen Narren. Des Weiteren wer-den Narrenattribute wie Narrenkolben, Narrengewand, Narrenkappe auf ihre Herkunft behandelt. Sowohl die Idee der Narrenfeste mit der Unterscheidung zwischen Karne-val, Fastnacht und Fasching als auch der Umgang mit psychischen Erkrankungen anhand historischer Quellen von Konrad von Megenberg und Paracelsus wird einge-gangen. Moralische Bedenken aufgrund einer vorgeworfenen Gottlosigkeit des Narren, aber auch eine gesellschaftliche Kritik im Narrenschiff von Sebastian Brant, sollen in dieser Abhandlung hinsichtlich ihres historischen Kontextes analysiert werden. Durch Bio-graphien diverser Hofnarren wie Claus von Ranstedt, Kunz von der Rosen, Gonella, Triboulet oder Brusquet, aber auch durch die Chroniken von Zimmern soll der Um-gang mit Narren und ihre Rezeption in der Kulturwissenschaft ermittelt werden. Die wissenschaftliche Betrachtung der Narrenfreiheit im Spannungsverhältnis zwischen Duldung und Privileg am Hof, sowie auch die Beziehung zwischen Herrscher und Nar-ren, ist die wesentliche Auseinandersetzung der vorliegenden Arbeit.

In this chapter the main focus lies on investigating and reproducing the paper “Capital supply uncertainty, cash holdings, and, investment” by Hugonnier et al. [6]. This paper models a financial environment, where the considered firm has to optimize its capital policy under some assumptions about availability of outside financing and investment opportunities. This optimization is done due to control of the dividends paid to the shareholders, the financing strategy and the investment strategy.

In this chapter we apply the dynamic programming approach with the corresponding HJB equation derived in the preceding parts in order to solve a special case of the above presented model. Note that the following solution approach is based on [6, p. 13 - 16 and p. 37 - 44]. In fact the model is restricted such that we are only considering firms without growth option, therefore the two main terms change.

In order to extensively characterize HMW-gliadins from wheat, an isolation method based on size exclusion chromatography was developed. The resulting protein fraction was analyzed using chromatographic, electrophoretic and mass-spectrometric methods. It was shown that HMW-gliadins are oligomeric proteins containing all gliadin types and glutenin subunits of wheat, which are cross-linked by intermolecular disulfide bonds. Systematic blocking of thiol groups showed that the native disulfide bonds of HMW-gliadin are affected by thiol-disulfide interchange reactions during extraction so that the size and composition of the oligomers depends on the conditions during extraction. HMW-Gliadine aus Weizen wurden durch Extraktion/Größenausschlusschromatographie isoliert. Die erhaltene Proteinfraktion wurde mit chromatographischen, elektrophoretischen und massenspektrometrischen Methoden charakterisiert. HMW-Gliadine sind oligomere, über intermolekulare Disulfidbindungen verknüpfte Proteine, an deren Bildung alle Gliadintypen und Gluteninuntereinheiten des Weizens beteiligt sind. Durch gezielte Blockierung von Thiolgruppen wurde gezeigt, dass die nativen Disulfidbindungen von HMW-Gliadinen durch Thiol-Disulfid-Austauschreaktionen bei der Extraktion beeinflusst werden, sodass die Größe und Zusammensetzung der Oligomere von den Extraktionsbedingungen abhängen.

Physical Review Letters, 121 (1), ISSN:0031-9007, ISSN:1079-7114

The frequently discussed mechanisms for the chlorine evolution reaction (CER)—Volmer–Tafel, Volmer–Heyrovsky, and Krishtalik—are assessed for the case of RuO2 within a mechanistic ab initio thermodynamics approach, employing the concept of Gibbs energy loss. The CER over the fully O-covered RuO2(110) surface, the stable surface configuration under CER conditions, is shown to proceed via the Volmer–Heyrovsky mechanism, i.e., the adsorption and discharge of the chloride ion are followed by the direct recombination of this surface species with a chloride ion from the electrolyte solution. The weak adsorption of the chloride ion on the fully O-covered RuO2(110) surface constitutes the elementary reaction step with highest Gibbs energy loss which has its origin in a too strong ruthenium–oxygen bond. Therefore, the activity of the model catalyst RuO2(110) can be enhanced by weakening the surface metal–oxygen bond such as realized with a monolayer of PtO2 coated on RuO2(110).

In the industrially important Chlor-Alkali process, the chlorine evolution reaction (CER) over a ruthenium dioxide (RuO2) catalyst competes with the oxygen evolution reaction (OER). This selectivity issue is elucidated on the microscopic level with the single-crystalline model electrode RuO2(110) by employing density functional theory (DFT) calculations in combination with the concept of volcano plots. We demonstrate that one monolayer of TiO2(110) supported on RuO2(110) enhances the selectivity towards the CER by several orders of magnitudes, while preserving the high activity for the CER. This win-win situation is attributed to the different slopes of the volcano curves for the CER and OER.

Constrained ab initio thermodynamics in the form of a Pourbaix diagram can greatly assist kinetic modeling of a particular electrochemical reaction such as the chlorine evolution reaction (CER) over RuO 2 (110). Pourbaix diagrams reveal stable surface structures, as a function of pH and the potential. The present DFT study indicates that the Pourbaix diagram in the CER potential region above 1.36 V and pH values around zero is dominated by a stable surface structure in which all coordinatively undercoordinated Ru sites (Ru cus ) are capped by on-top oxygen (O ot ). This oxygen saturated RuO 2 (110) surface is considered to serve as the catalytically active phase in the CER, quite in contrast to the heterogeneously catalyzed HCl oxidation (Deacon process), for which the active RuO 2 (110) surface is mainly covered by on-top chlorine. The active sites in the CER are suggested to be Ru cus O ot surface complexes, while in the Deacon process both undercoordinated surface Ru and oxygen sites must be available for the activation of HCl molecules.

The numerical and experimental investigation of non-axisymmetric casing treatments is complex compared to axisymmetric ones like circumferential grooves. Hence they are still rarely investigated, at least regarding combinations of numerical and experimental work on the same configuration. The casing treatment under investigation is capable of significantly broadening the operating range of a tip-critical transonic compressor. This is accomplished without an efficiency penalty at design conditions. It is demonstrated that the application of a casing treatment over the rotor might impose negative effects on the downstream stator that would have to be considered in future designs. Earlier work by the authors was focused on the experimental investigation, in particular of transient effects near stall. In this paper, RANS and URANS simulations are presented in detail. These are used to further study and explain the causes of the effects that were found experimentally. Additional experimental data are added where appropriate, continuing the validation of the numerical methods.

Current progress in modern electrocatalysis research is spurred by theory, frequently based on ab initio thermodynamics, where the stable reaction intermediates at the electrode surface are identified, while the actual energy barriers are ignored. This approach is popular in that a simple tool is available for searching for promising electrode materials. However, thermodynamics alone may be misleading to assess the catalytic activity of an electrochemical reaction as we exemplify with the chlorine evolution reaction (CER) over a RuO2 (110) model electrode. The full procedure is introduced, starting from the stable reaction intermediates, computing the energy barriers, and finally performing microkinetic simulations, all performed under the influence of the solvent and the electrode potential. Full kinetics from first-principles allows the rate-determining step in the CER to be identified and the experimentally observed change in the Tafel slope to be explained.

Motivated by our previous studies on metallic substrates, in the present work we addressed the functionalization and the subsequent metallization of a hydrogen-terminated n-Si(111) electrode. DFT provides atomistic insights on the grafting mechanism of 4-pyridinecarboxaldehyde (C6H5NO) what encouraged electrochemical investigations, i. e. cyclic voltammetry and in-situ STM, combined with XPS measurements which together provide evidence for a successful transfer of the so far obtained knowledge from metal single crystal to semiconductor surfaces.

Predicting the reactivity of catalytic systems is a nontrivial process that usually requires knowledge about its geometric and electronic structure, properties determined by quantum mechanics (QM). Solving the Schr€odinger equation is a nontrivial task even for small systems, and it becomes especially arduous when the system involves multiple phases as is the case in a surface reaction. Theoretical calculations nevertheless provide useful and important perspectives on chemical reactions that are not accessible through experimental observations alone. Figure 1.1 schematically shows the hierarchy of multiscale modeling, starting from the subatomic regime, over the electronic and atomistic regimes, to themesoand finally the macroscale. Different theoretical methods have been established to address questions related to each regime (or timescale and length scale); however, realistic processes usually involve effects from all scales. In this chapter, we will focus on the electronic and atomistic regimes, which not only provide the basis for climbing up the hierarchy of multiscale modeling but also provide important mechanistic information on catalytic reactions. Quantum chemistry is the application of QM to better understand chemical systems. In its purest form, QM calculations solve the Schr€odinger equation, which provides the energy of a given configuration of nuclei and their electrons. There are two general approaches to do this. One way is to solve the energy given by the Schr€odinger equation approximately using a nonclassical wavefunction. Another popular approach, density functional theory (DFT), uses the electronic density to evaluate the energy of a system via an approximate functional. Both approaches have their merits and provide a nonthermodynamical representation of the energy of a system of electrons. This chapter gives an introductory overview of the essential concepts behind theoretical calculations of surface reactions, which we then apply to better understand one of the key features in energy conversion and fuel cell technology

We describe a multiscale modeling hierarchy for the particular case of Au-island ripening on Au(100). Starting at the microscopic scale, density functional theory was used to investigate a limited number of self-diffusion processes on perfect and imperfect Au(100) surfaces. The obtained structural and energetic information served as basis for optimizing a reactive forcefield (here ReaxFF), which afterwards was used to address the mesoscopic scale. Reactive force field simulations were performed to investigate more diffusion possibilities at a lower computational cost but with similar accuracy. Finally, we reached the macroscale by means of kinetic Monte Carlo (kMC) simulations. The reaction rates for the reaction process database used in the kMC simulations were generated using the reactive force field. Using this strategy, we simulated nucleation, aggregation, and fluctuation processes for monoatomic high islands on Au(100) and modeled their equilibrium shape structures. Finally, by calculating the step line tension at different temperatures, we were able to make a direct comparison with available experimental data.

The mechanisms of formic acid (HCOOH) oxidation on Pt(111) under electrochemical conditions have been studied using density functional theory and then compared with the analogous gas-phase reaction. Results show that HCOOH oxidation under a water-covered surface behaves substantially differently than in the gas phase or using a solvation model involving only a few water molecules. Using these models, we evaluated the detailed reaction process, including energies and geometric structures of intermediates and transition states under the influence of different solvation models and electrode potentials. Our calculations indicate that this potential-dependent electrochemical oxidation proceeds via a multipath mechanism (involving both the adsorbed HCOOH and HCOO intermediates), a result succinctly rationalizing conflicting experimental observations. Moreover, this study highlights how subtle changes in electrochemical reaction environments can influence (electro)catalysis.

Highly differential experimental results of the scattering system He++ on He at 30 keV are presented as well as a complete unified theoretical description where excitation, transfer and ionization are treated simultaneously on an ab initio level. The agreement even for highly differential cross sections is nearly complete although no explicit correlation besides Pauli correlation is included in the calculations.

In the industrially important Chlor-Alkali process, the chlorine evolution reaction (CER) over a ruthenium dioxide (RuO2) catalyst competes with the oxygen evolution reaction (OER). This selectivity issue is elucidated on the microscopic level with the single-crystalline model electrode RuO2(110) by employing density functional theory (DFT) calculations in combination with the concept of volcano plots. We demonstrate that one monolayer of TiO2(110) supported on RuO2(110) enhances the selectivity towards the CER by several orders of magnitudes, while preserving the high activity for the CER. This win-win situation is attributed to the different slopes of the volcano curves for the CER and OER.

The first extraction of graphene in 2004 led to a wide range of experimental and theoretical studies aimed at better understanding and exploiting the unique properties of this novel two-dimensional material. Among the many potential applications, which have been suggested, are uses of graphene as a substrate in high-performance catalysis and as a component in circuit-board technology. In particular, graphene s high surface area and conductivity have motivated proposals to use it as a substrate for growing and/or anchoring metal nanoparticles in high-performance catalysts and other electrochemical devices. However, the activity of such carbon-supported metal catalysts is strongly dependent on the dispersion and stability of the metal clusters on the support (i.e. the ability of the substrate to stabilize metal clusters of various sizes on its surface). Thus, vacancy defects are expected to play a vital role in making graphene suitable for these applications by supplying highly active binding sites for adsorbing and stabilizing metal clusters. Indeed, finite populations of single and double vacancy defects are thermodynamically stable in graphene, and have been studied extensively. Density functional theory (DFT) calculations revealed that vacancy defects resulting from the removal of up to five C atoms reconstruct to form non-hexagonal rings (models are shown in the Supporting Information: Figures S1.b–f). Even larger holes have been observed in electron microscopy experiments. Defects may also play a critical role in using graphene components for circuit fabrication. For example, taking advantage of the Dirac fermions in graphene requires opening up its band gap to convert it from a conductor into a semiconductor. This conversion can be achieved by doping graphene with either B or N atoms; however, another possibility for accomplishing this could be the adsorption of small metal clusters on the surface. Because the adsorption of such clusters can be used to tune additional magnetic and transport properties of the substrate, it might also provide a technique for controlling an additional set of electromagnetic properties. The catalytic nature of Ni is well established, and Ni nanoparticles are commonly used to catalyze the synthesis of carbon nanostructures. Owing to the strong affinity between Ni and C, the incorporation of Ni atoms into carbon nanostructures, grown using Ni catalysts, has been observed. Ushiro et al. reported that X-ray adsorption measurements detect Ni impurities in carbon nanostructures following nickel-catalyzed synthesis, which even treatment with acid is not able to remove. Moreover, Banhart et al. identified Ni impurities wrapped in onion-like graphenic particles by using electron microscopy. The work of Rinaldi et al. is even more supportive. Combining results from DFT calculations and high-resolution transmission electron microcopy measurements (HR-TEM) utilizing several in situ characterization techniques, they concluded that Ni atoms form very stable Ni– C compounds during nickel-catalyzed carbon nanotube (CNT) growth, which are incorporated into the final products. They also found unexpectedly strong adsorption of the Ni clusters on the CNT supports. However, despite the potential advantages of using Ni nanoparticles adsorbed on graphene, their catalytic and electromagnetic properties (with the exception of single and two Ni atoms adsorbates) remain mostly unexplored. Based on these findings, it would be expected that just as Ni nanoparticles might be used to tailor critical properties of defective graphene sheets, a graphene substrate might be used to modify the catalytic properties of nickel nanoparticles as well. To elucidate this potential interplay we employ DFT to study the adsorption of Nin nanoclusters on defective graphene (details in the Supporting Information). As substrate models we select graphene sheets with vacancy defects, resulting from the removal of x atoms (with x 5; see Figure S1 in the Supporting Information). To model the adsorbed Ni nanoparticles, we successively grew Nin clusters with n 10 and focused on the lowest energy adsorption configuration of each Nin cluster on each of these six graphene substrates (with and without vacancy defects). The binding energies (referenced against single Ni atoms and the graphene substrate) for the lowest energy configuration are summarized in Figure 1. The binding energies can be explained by three types of bond contributions. The first type of binding is between Ni atoms. As the cluster size increases the ratio of bulk to surface atoms increases so that the binding energy will asymptotically [*] Dr. W. Gao, Dr. J. E. Mueller, Dr. J. Anton, Prof. Dr. T. Jacob Institut f r Elektrochemie, Universit t Ulm 89081 Ulm (Germany) E-mail: timo.jacob@uni-ulm.de

Alloy Pt-M (M = Co, Ni) nanocatalysts, supported on carbon Vulcan XC-72, were synthesized using the carbonyl chemical route. A high dispersion on such substrate was revealed by transmission electron microscopy (TEM). Alloy formation on the nanometre scale length was shown by high-resolution transmission microscopy (HRTEM) and energy dispersive X-ray spectroscopy (EDX) on a nanoparticle. The metal M in Pt-M nanoalloys segregates preferentially on the nanoparticles' surface, as determined by the hydrogen adsorption electrochemical reaction. An increased tolerance towards methanol of such nanoalloy materials was observed for the oxygen reduction reaction (ORR) in acid media. To better understand the structure and segregation phenomena of these nanoalloys, molecular dynamics (MD) with a self-optimized reactive force field was applied.

Formic acid (HCOOH) oxidation on Pt(111) under gas-phase conditions is a benchmark heterogeneous catalysis reaction used to probe electro-catalytic HCOOH conversion in fuel cells, itself an important reaction in energy conversion. We used density functional theory (DFT) calculations to elucidate the fundamental oxidation mechanisms of HCOOH in the gas phase, determining the relative strengths of chemical interactions between HCOOH oxidation intermediates and the Pt(111) surface. We focused on investigating how water and adsorption coverage affects reaction intermediate structures and transition states. Our results show that adsorbed HCOO is a reactive intermediate in gas phase, and co-adsorbed water plays a key role in HCOOH oxidation influencing the structure of reaction intermediates and reaction barriers on Pt(111). The simulations show the preferred catalytic pathway is qualitatively dependent on surface coverage. These results provide a conceptual basis to better interpret its complicated experimental reaction kinetics.

The relationship between urodele regeneration and possible regeneration in mammalian prospects is hard to evidence, but the idea of possible regeneration of neural elements in people is an area of potential clinical importance that is under investigation. One of the great challenges of the future is to understand enough about the basic biology of animal regeneration and to use it for the betterment of the mankind. It is well established that the initial stages of urodele limb regeneration depend on the presence of intact nerve fibres connected to their cell bodies. The nerve fibres severed at the limb amputation level, regrow and invade the blastema, providing blastema cells with indispensable factors. These factors are elaborated within the neuron perikarya and transported via their axons to the blastema. Numerous studies have been so far performed and have elucidated the quantitative relationships between nerve fibres and limb regeneration. However, there are no reports dealing with the individual nerve cells at work. The aim of the present investigation was to analyse the quantitative participation and qualitative distinction of nerve cells innervating regenerating parts of the urodele limb and their possible interrelationship with the nerve-dependent and nerve-independent periods of regeneration. The cells under study are housed in the dorsal ganglia (sensory neurons) and in the ventral aspect of the spinal cord grey matter (motor neurons). As a means of visualizing the direct implication of these neurons during various regeneration periods, the enzyme horseradish peroxidase was chosen. A total of 34 animals were used, 21 experimental and 13 controls, in order to study labeled nerve cell fluctuations. The results are summarized as follows: (a) The first nerve cells incorporating HRP within 5 days post amputation are found in the dorsal ganglia. Motor neurons in the grey matter are labeled within 7 days. (b) The number of labeled perikarya increases during the nerve-dependent regeneration period (0-21 dpa). The percentage of implicated sensory neurons exceeds that found in the control series. (c) During the next, nerve-independent period, the number of participating labeled neurons decreases gradually. Such fluctuations in the number of labeled neurons might represent the metabolic status of these cells in their effort to provide the blastema cells with the factors needed at the appropriate time. The current findings support previous observations that the periods of dependence and independence of urodele limb regeneration from the integrated control of brachial nerves reflect changes in the metabolism of individual sensory and motor neurons.

We perform a comparative country-by-country study of companies going public in the six largest Continental European markets and Sweden during 1988 and 1998, a time period characterized by IPO activity in a broad set of industries. By applying a common research methodology, we find broad similarity in the overall and cross-sectional initial pricing and long-run performance patterns. Positive long-run IPO performance is a function of a countries' ability to attract "New Economy" IPOs. This helps to shed some light on the rational behind the frantic efforts made be individual European Stock Exchanges to establish "New Market" segments during the late 1990s.

We study the relationship between management behaviour and the subsequent market response in the German IPO market. When applying two forms for earnings management, issuers that overperform in the long run manage earnings less aggressively. Over shorter measurement horizons, however, the performance is sensitive to the starting date of the measurement period. The market takes a considerable time to respond to the fundamental message conveyed by management behaviour towards earnings management at the time of the IPO. Within the first four months, IPO returns are essentially driven by factors other than fundamentals. This sheds light on the dynamics of IPO performance and the efficiency of the IPO aftermarket.

Continental European markets and Sweden during a period characterized by dramatic change. For a sample of 973 IPOs during 1988 and 1998, there is considerable underpricing which is time-varying and related to company characteristics. Much of the large "amounts of money left on the table" is due to privatization issues. For the sample as a whole, IPOs did not underperform in the long-run. Over shorter measurement horizons, we find overperformance. IPO performance is sensitive to market condition at the time of going public and IPO issuing characteristic. The favourable performance for the sample as a whole is driven by New Economy IPOs accounting for 28 percent of the sample. The pervasiveness of the outperformance of New Economy IPOs sheds light on the drivers behind the dramatic shift in industry composition of European IPOs in favor of New Economy IPOs during the "Internet Bubble".

This analysis provides evidence regarding the performance of Initial Public Offerings (IPOs) in Europe during a time of dramatic change. For the sample of 973 IPOs taken from the six major Continental European markets and Sweden during 1988-98, there is significant underpricing and autocorrelation in IPO underpricing and activity. Privatization programs account for most of the "money left on the table". For the sample as a whole, we do not find long-run underperformance. Over shorter measurement horizons, IPOs outperform the market. The favourable performance is driven by New Economy IPOs, which account for 28 percent of the sample. The pervasiveness of these results across various methodological choices is puzzling and shows one of the forces behind the dramatic shift in industry composition of IPOs in favour of New Economy IPOs during the "Internet Bubble" of 1999 and 2000. Underpricing extends across all countries studied, with IPO activity being partially influenced by changes in tax regimes or in the regulatory framework. There is also a strong link between IPO performance and the national exchanges' ability to attract New Economy IPOs. This fundamentally explains why stock exchanges have attempted to establish "New Market" segments during the 1990s. Tests for performance differences between countries confirm the homogeneity of the European IPO market. In order to shed more light on the results, we study the relationship between management behaviour towards earnings management and the subsequent market response for the German IPO market. When applying two forms of earnings management, issuers that overperform in the long-run tend to manage earnings less aggressively. Over shorter measurement horizons, however, the performance is sensitive to the starting date of the measurement period. The market takes a considerable amount of time to respond to the fundamental message conveyed by management behaviour towards earnings management. Within the first four months, IPO returns are essentially driven by factors other than fundamentals. Apart from casting doubt on the efficiency of the IPO aftermarket, this can explain the observed negative relationship between short- and long-run IPO returns and the rationale behind investing in IPOs.

A supersonic beam of Rydberg hydrogen atoms has been adiabatically deflected by 90 degrees decelerated to zero velocity in less than 25 mu s and loaded into an electric trap. The deflection has allowed the suppression of collisions of the Rydberg atoms with atoms in the trailing part of the gas pulse. The processes leading to trap losses i.e. fluorescence to the ground state and transitions and ionization induced by blackbody radiation have been monitored over several milliseconds and quantitatively analyzed.

Using density functional theory and thermodynamic considerations, adsorbate-induced faceting of high-index metal surfaces such as Ir(210) and Re(112 1) has been studied. Focusing on these two systems we first discuss the adsorption behaviour of oxygen and nitrogen on the various surfaces relevant for the faceting, and afterwards use these energies to evaluate the stability of substrates and facets in the presence of oxygen and nitrogen. The faceting phase diagrams of Ir(210) and Re(112 1) show that both adsorbates enhance the anisotropy in surface free energy, finally causing nanofacets to become the thermodynamically favourable surface structure. We also generated analogous electrochemical phase diagrams for both surfaces in contact with an oxygen- or nitrogen-containing electrolyte and found that the same nanofacets should also become stable at positive electrode potentials. Thus, our calculations not only reproduce the experimentally observed surface faceting under UHV conditions, but also predict facet formation under electrochemical conditions.

Im IV. Jahrgange der , Monatshefte ffir ~athe..matik und Physik" (pag. 2~7--293) habe ich eine Arbeit mit der Uberschrih: ,Rein analytische tterleitung der Transformationsgleichung f~ir eigentliche Doppelintegrale mit Itilfe des Green ' sehen Satzes" ver0ffentlicht~ in welcher die Verwendbarkeit des G r e e n ' s c h e n Satzes zur Ableitung der Transformationsgleiehung f~ir Doppelintegrale dargethan wurde. Da nun andrerseits der Green ' sehe Satz oder~ allgemeiner gesprochen~ die Randintegration ffir ein n-laches Integral dem Wesen nach auf die Transformation eines (n--1)-faehen Integrales zurfickftihrt~ so gelangte ich sehon damals bei der Ausfiihrung der genannten Arbeit zu der l~berzeugung~ dass die wechselweise Zurfiekffihrung der Randintegration auf eine Transformation und der Transformation auf eine Randintegration ein wertvolles l~Iittel an die tIand geben werde, mit dessen Hilfe die Gleiehungen ftir die Randintegration und Transformation beliebig vielfaeher lntegrale auseinander abgeleitet werden kSnnten~ beziehungsweise deren Giltigkeit bewiesen werden k0nnt% und dass endlieh d e r Schluss yon n auf n-~-1 die volle Allgemeingiltigkeit dieser Gleiehungen verbtirgen werde. Dutch auderweitige Arbeit verhindert~ kam ieh jedoeh erst in der letzten Zeit dazu~ diesen Gedanken weiter zu verfolgen und zu realisieren. Der Erfolg war der Erwartung vollkommen entsprechend~ indem es sich herausstellte~ dass sieh das in der genannten Abhandlung bereits eingeschlagene Verfahren ohm~ besondere Schwierigkeiten ganz allgemein auf beliebig vielfache Integrale anwenden lasse. Aueh die Ableitung der Randintegration~ welehe in der frfiheren Abhandlung nicht vorkommt~ konnte dem Wesen naeh auf dieselben Grundlagen aufgebaut werclen~ auf welehen das dort eingehaltene Verfa~hren ful~t. Die Grundlage der ganzen Untersuehung bildet die Darstellung des Integrationsgebietes. Es erscheint daher nothwendig~ die nun folgende Abhandlung~ welehe den Verlauf und die Resultate meiner dem Inhalte naeh bereits skizzierten Untersuehung zur DarsteUung bringt, mit einigen Erliiuterungen fiber die Bezeiehnungsweise und die mathematisehe Definition eines Gebietes yon n unabhl~ngigen Veriinderliehen zu beginnen.