Holding on for too long? An experimental study on inertia in entrepreneurs’ and non-entrepreneurs’ disinvestment choices

Disinvestment, in the sense of project termination and liquidation of assets including the cession of a venture, is an important realm of entrepreneurial decision-making. This study presents the results of an experimental investigation modeling the choice to disinvest as a dynamic problem of optimal stopping in which the patterns of decisions are analyzed with entrepreneurs and non-entrepreneurs. Our experimental results reject the standard net present value approach as an account of observed behavior. Instead, most individuals seem to understand the value of waiting. Their choices are weakly related to the disinvestment triggers derived from a formal optimal stopping benchmark consistent with real options reasoning. We also observe a pronounced ‘psychological inertia’, i.e., most individuals hold on to a losing project for even longer than real options reasoning would predict. The study provides evidence for entrepreneurs and non-entrepreneurs being quite similar in their behavior.Real-Options, Disinvestment, Exit Behavior, Experimental Economics, Agribusiness, Agricultural and Food Policy, Agricultural Finance, Institutional and Behavioral Economics,

The Maximum Flow Problem for Oriented Flows

In several applications of network flows, additional constraints have to be considered. In this paper, we study flows, where the flow particles have an orientation. For example, cargo containers with doors only on one side and train coaches with 1st and 2nd class compartments have such an orientation. If the end position has a mandatory orientation, not every path from source to sink is feasible for routing or additional transposition maneuvers have to be made. As a result, a source-sink path may visit a certain vertex several times. We describe structural properties of optimal solutions, determine the computational complexity, and present an approach for approximating such flows

Closing down the Farm: An Experimental Analysis of Disinvestment Timing

Agrarian structures are often characterized by some kind of economic inertia. It is particularly puzzling why unprofitable farms persist over time instead of being sold. In this paper we analyze the exit decision of farmers using the real options approach. The validity of the real options theory is assessed by means of laboratory experiments. Our results show that real options models are able to predict actual disinvestment decisions better than traditional investment theory. Nevertheless, the observed disinvestment reluctance was even more pronounced as predicted by theory. This finding suggests the inclusion of bounded rationality into normative disinvestment models.Disinvestment, Real Options, Experimental Economics, Agricultural Finance, Farm Management, C91, D81, D92,

Laserbasierte Synthese und Funktionalisierung von graphitischen Grenzflächen

Der Fokus dieser Arbeit liegt auf laserbasierten Verfahren die die Synthese und Modifikation von graphitischen Materialien erlauben. Graphitische Materialien befinden sich im Fokus der aktuellen wissenschaftlichen Forschung und gewinnen zunehmend an Bedeutung in zahlreichen vielversprechenden Anwendungen. Neben mikro- und nanoelektrische Anwendungen sind graphitische Materialien z.B. vielversprechende Füllstoffe in Polymer-Kompositmaterialien. Ziel dieser Arbeit ist es zu demonstrieren das laserbasierte Verfahren für die die Synthese und die gezielte Oberflächenmodifikation von graphitischen Grenzflächen eingesetzt werden können. Aufgrund der geringen experimentellen Aufwand sowie die hohe Flexibilität von laserbasierten Verfahren können sich so neue Wege zur Herstellung, Modifizierung und Funktionalisierung graphitischer Grenzflächen für Anwendungen in der Energietechnik und Elektronik eröffnen. Konkret wird in dieser Arbeit die Synthese von graphitischen Grenzflächen auf SiC durch einen ultravioletten Dauerstrich-Laser vorgestellt. Durch das lokale Bearbeiten mit dem Laser könnten so lokale graphitische Strukturen aufgebaut werden, was insbesondere im Hinblick auf elektronische Schaltungen von Interesse sein kann. Weiterhin wird demonstriert, dass sich mithilfe von funktionellen, organischen Schichten in Kombination mit einem Laserverfahren die Oberflächeneigenschaften von graphitischen Materialien gezielt modifizieren lassen. Der letzte Teil der Arbeit zeigt die große Flexibilität sowie die Möglichkeit des einfachen Upscaling von laserbasierten Verfahren. Hier wird ein Verfahren vorgestellt, mit dem es möglich ist, das Benetzungsverhalten von Graphit/Polymer-Kompositmaterialien anzupassen. Ziel war die Anpassung war die Verbesserung des Wassermanagment in einer PEM-Brennstoffzelle die aus diesem Material bestehen.The topic of this thesis is the laser-based synthesis and modification of graphitic materials. Graphitic materials are in the focus of the current scientific research and becoming increasingly important in many promising applications. Besides micro- and nanoelectronic applications graphitic materials are promising fillers in polymer composites. The aim of this thesis is to demonstrate that laser-based methods can be beneficial for the synthesis and selective surface modification of graphitic interfaces. Because of the small experimental effort and the high flexibility of laser-based methods, new ways of production, modification and functionalization of graphitic interfaces for applications in e. g. electronics are feasible. Specifically, the synthesis of graphitic interfaces on SiC single crystal by an ultraviolet continuous-wave laser (λ = 355 nm) is presented in this thesis. By laser processing local graphitic structures can be built up. These graphitic structures are characterized and the underlying mechanism is discussed. Furthermore, it is demonstrated that the surface properties of graphitic materials can be engineered via functional organic layers in combination with a laser induced process. First graphitic substrates (highly oriented pyrolytic graphite, HOPG) are coated with a self assembled monolayer (SAM). Subsequently through local induced bromination with an argon ion laser beam (λ = 514 nm) bromine groups are introduced into the SAMs. This can be the starting point for further chemical modifications. The last part of the thesis shows the great flexibility and the possibility of simple upscaling of laser-based methods. Here a method is presented, with which it is possible to adjust the wetting behaviour of graphite/polymer composites. The aim was to improve the water management in a PEM fuel cells which are produced out of this graphite/polymer compound. For this purpose, a combination of a coating routine and laser processing with a pulsed nanosecond laser (λ = 514 nm) is used

ZUM DESINVESTITIONSVERHALTEN LANDWIRTSCHAFTLICHER UNTERNEHMER: ERGEBNISSE EINER EXPERIMENTELLEN UNTERSUCHUNG

Desinvestition, Realoptionsansatz, Experimentelle Ökonomik, Agricultural Finance, Farm Management, Financial Economics, Research Methods/ Statistical Methods,

Customizing the appearance of sparks with binary metal alloys

Long-flying sparks are an essential part of several pyrotechnic effects. Unfortunately, and in contrast to colored flames, the color space of sparks is basically limited to the black-body curve. With low-boiling metals, vapor phase combustion and bright colorful flashes are achievable. In 1999, alloys of rare-earth elements have been proposed for colorful spark genera-tion. To the best of our knowledge, here we present the first investigation of such alloys to change the color of sparks be-yond the black-body limit. Alloys consisting of >65 at.-% of a brightly emitting and low-boiling metal and a carrier metal allow achieving long-flying deeply colored sparks. Besides the color, branching of sparks is crucial for the visual appear-ance. Rare-earth metals were found to promote branching of different alloys. Finally, fountains ejecting golden/green sparks based on a stable eutectic Yb-Cu alloy and continuously branching sparks based on Nd2Fe14B are presented

Kinase domain mutations confer resistance to novel inhibitors targeting JAK2V617F in myeloproliferative neoplasms

The transforming JAK2V617F kinase is frequently associated with myeloproliferative neoplasms (MPNs) and thought to be instrumental for the overproduction of myeloid lineage cells. Several small molecule drugs targeting JAK2 are currently in clinical development for treatment in these diseases. We performed a high-throughput in vitro screen to identify point mutations in JAK2V617F that would be predicted to have potential clinical relevance and associated with drug resistance to the JAK2 inhibitor ruxolitinib (INCB018424). Seven libraries of mutagenized JAK2V617F cDNA were screened to specifically identify mutations in the predicted drug-binding region that would confer resistance to ruxolitinib, using a BaF3 cell-based assay. We identified 5 different non-synonymous point mutations that conferred drug resistance. Cells containing mutations had a 9 to 33-fold higher EC50 for ruxolitinib compared to native JAK2V617F. Our results further indicated that these mutations also conferred cross-resistance to all JAK2 kinase inhibitors tested, including AZD1480, TG101348, lestaurtinib (CEP-701) and CYT-387. Surprisingly, introduction of the ‘gatekeeper’ mutation (M929I) in JAK2V617F affected only ruxolitinib sensitivity (4-fold increase in EC50). These results suggest that JAK2 inhibitors currently in clinical trials may be prone to resistance as a result of point mutations and caution should be exercised when administering these drugs

Electrical tuning of the oscillator strength in type II InAs/GaInSb quantum wells for active region of passively mode-locked interband cascade lasers

This project has received funding from the European Commission's Horizon 2020 Research and Innovation Programme iCspec under grant agreement No. 636930 and has also been supported by the National Science Centre of Poland within Grant No. 2014/15/B/ST7/04663.Two designs of active region for an interband cascade laser, based on double or triple GaInSb/InAs type II quantum wells (QWs), were compared with respect to passive mode-locked operation in the mid-infrared range around 4 µm. The layer structure and electron and hole wavefunctions under external electric field were engineered to allow controlling the optical transition oscillator strength and the resulting lifetimes. As a result, the investigated structures can mimic absorber-like and gain-like sections of a mode-locked device when properly polarized with opposite bias. A significantly larger oscillator strength tuning range for triple QWs was experimentally verified by Fourier-transform photoreflectance.Publisher PDFPeer reviewe

Electric mobility concepts and their significance for the economy, society and the environment. Summary

Electromobility is currently fuelling hopes worldwide for a more sustainable development of the transport sector. The TAB report analyses ecological, economic and social aspects of electromobility for Germany and compares them with those of conventional automobiles. The ecological balance is particularly in favour of electromobility when low- or zero-CO2 energy sources are used, because in addition to greenhouse gases, other pollutant emissions are also significantly reduced. The economic analysis examines economic efficiency, implications for the automotive value chain and jobs, and the supply of critical raw materials. With a future stronger diffusion of electromobility in Germany, slightly positive effects on the employment situation and the development of GDP are expected. The social implications are examined on the basis of acceptance, user behaviour, traffic noise and accidents. The report shows that a positive user acceptance can be achieved with a wider range of models while complying with common quality and comfort standards as well as extended test possibilities, but also by reducing acquisition costs, a wider range of user-friendly mobility and business models and, last but not least, a transparent positive environmental balance. On the basis of the analyses, critical aspects and potentials of electric mobility are discussed, leading to policy-relevant conclusions and options for action

Equilibrium shapes of poly-crystalline silicon nanodots

This study is concerned with the topography of nanostructures consisting of arrays of poly-crystalline nanodots. Guided by transmission electron microscopy (TEM) measurements of c-Si nanodots that evolved from a "dewetting" process of an a-Si layer from a SiO2 coated substrate, we investigate appropriate surface energy density formulations to model these equilibrium geometries. We explore the influence of smooth transitions between the energy density states at grain boundaries on the associated surface morphology of the equilibrium poly-crystals. Furthermore, we introduce a new numerical minimization formulation that allows to account for adhesive energy from an underlying substrate. We demonstrate our approach first for the unbounded case, where the solutions can be compared to well-known Wulff constructions, before we treat the general case for interfacial energy settings that support partial 'wetting'. Eventually, we use the method to study two-dimensional shapes of poly-crystalline silicon nanodots