Методы добычи сланцевого газа и их воздействие на окружающую среду

We have studied GaAs/AlGaAs- and GaAs/AlAs-samples grown by molecular beam epitaxy by X-ray scattering under grazing angles to investigate surface and interface roughness. We discuss the reliability of buried interface roughnesses derived from fits to specular reflectivity by means of a sample series grown at substrate temperatures from 605 to 685°C. Even for samples of high perfection no abrupt interfaces were found. We have applied this method to the problem of growth-induced roughening of GaAs- and AlAs-layers. Sample series with increasing film thickness between 50 and 2000 Å for AlAs and 5000 Å for GaAs have been investigated. We observe roughening which in the case of AlAs does not follow a power law expected within the framework of kinetic roughening theory. However, for GaAs the data can be described by a very small growth exponent β = 0.11 ± 0.03

Emerging IT risks: insights from German banking

How do German banks manage the emerging risks stemming from IT innovations such as cyber risk? With a focus on process, roles and responsibilities, field data from ten banks participating in the 2014 ECB stress test were collected by interviewing IT managers, risk managers and external experts. Current procedures for handling emerging risks in German banks were identified from the interviews and analysed, guided by the extant literature. A clear gap was found between enterprise risk management (ERM) as a general approach to risks threatening firms’ objectives and ERM’s neglect of emerging risks, such as those associated with IT innovations. The findings suggest that ERM should be extended towards the collection and sharing of knowledge to allow for an initial understanding and description of emerging risks, as opposed to the traditional ERM approach involving estimates of impact and probability. For example, as cyber risks emerge from an IT innovation, the focus may need to switch towards reducing uncertainty through knowledge acquisition. Since individual managers seldom possess all relevant knowledge of an IT innovation, various stakeholders may need to be involved to exploit their expertise

PRODUCTION AND THERMAL ANNEALING OF LATTICE DEFECTS IN KCl

Recherches sur la production de défauts dans les halogénures alcalins par irradiation X. On effectue sur KCl des mesures associées du changement macroscopique de volume et de celui du paramètre du réseau. Des centres colorés sont formés dans KCl coloré par addition, de lacunes de défauts de Schottky, tandis que dans KCl irradié, ils sont formés de lacunes qui font partie de défauts de Frenkel. En outre la production de lacunes. c. à d. de centres α plus F par les rayons X dans KCl de différentes origines, avec différentes densités de dislocations et différentes impuretés divalentes, est étudiée à la température de l'hélium liquide. Le comportement pendant le réchauffement des centres α, F et H et celui d'une bande d'absorption à 195 nm montre que, pendant l'irradiation X à la température de l'hélium liquide, des lacunes et des défauts interstitiels se forment dans KCl, et qu'ils se recombinent à différents stades du recuit. L'analyse des courbes de recuit donne les énergies d'activation et les ordres des réactions. A la suite des expériences d'irradiation et de recuits combinés aux températures de He et de N2 liquides, on a conclu que le même processus primaire doit intervenir dans la formation des défauts à ces deux températures.Some investigations were performed to obtain more information about the production of defects in alkali halides during X-irradiation. Combined measurements of the macroscopic volume change and the change of the lattice parameter of KCl were performed. Color centers in additively colored KCl are formed from Schottky-defect vacancies, whereas in X-irradiated KCl they are formed from vacancies which are parts of Frenkel defects. Further, the production of vacancies, i. e. α plus F centers by X-rays in KCl of different origins, dislocation densities and of different divalent impurities is studied at liquid helium temperature. It is concluded that the generation of vacancies at liquid helium temperature is an intrinsic process. The annealing behaviour of α, F and H centers and the annealing of an absorption band at 195 nm shows, that during X-irradiation at liquid helium temperature vacancies and interstitials are formed in KCl which recombine in distinct annealing stages. An analysis of the annealing curves gives the activation energy and the order of reaction. It is concluded from combined irradiation and annealing experiments at liquid helium and at liquid nitrogen temperature that the same primary process should be valid for the defect formation at liquid helium and at liquid nitrogen temperature

Wetting transition of a binary liquid mixture at a solid boundary

We present the observation of a first-order wetting transition of the binary liquid mixture 2-propanol and perfluoromethylcyclohexane at a liquid-solid interface, where one component (2-propanol) of the gravity-separated mixture is selectively adsorbed on the surface of a silicon substrate. The system undergoes a wetting transition from a thin adsorbed film to a macroscopic wetting layer at T_{\ab w} = 50.6\un{^\circ C} with pronounced premonitory growth of the adsorbed film. The microscopic density profile of the prewetting film is derived from fits to temperature-dependent X-ray reflectivity measurements. Our experimental data clearly indicate a film structure dominated by strong density gradients, which is in contrast to the frequently used “homogeneous slab” models, but confirms density functional calculations. Time-resolved measurements during equilibration reveal new details of the adsorption film growth process, in particular the existence of separate density and thickness growth regimes

The benefits of crowdfunding for early-stage entrepreneurs: Between finance gap and democratic involvement

Crowdfunding has fundamentally impacted the world of entrepreneurial finance by providing a new alternative to equity, debt and bootstrapping which allows entrepreneurs to leverage 'the crowd’ in order to generate financial investment and further ‘value-added’ benefits (Belleflamme et al., 2014; Harrison, 2013; Ordanini et al., 2011) generating £2.7 billion of investment in 2012 (Massolution, 2013). While research has begun to develop understanding of the phenomenon, this has tended to focus on the dynamics of investment platform activity, rather than the experiences of the entrepreneurs who engage in this activity. This paper empirically investigate the perceptions of benefits by early-stage entrepreneurs involved in one of the most common forms of crowdfunding; reward-based. Through thematic analysis of interviews with a pilot sample of 2 experts and 5 early-stage entrepreneurs, benefits were identified, explored and contrasted with the literature and an existing conceptual framework before being explained. This resulted in a new empirically contextualised ‘benefits’ conceptual framework. Some of the anticipated benefits in the literature including overcoming finance difficulties and providing a basis for future finance were supported. Whilst the literature emphasises democratic investor involvement through financing decisions, the results of interviews indicated that investor involvement was more wide ranging and diverse, from simple investment to continuous engagement in the development of the business, supporting an understanding of how democratic involvement of the ‘crowd’ actually occurs. Furthermore, a number of drawbacks to crowdfunding are identified, such as the onerous time commitments of engaging in crowdfunding. Overall, the approach of each entrepreneur, their engagement with investors and the benefits they realised was found to be influenced by their personal ambitions and approach. The empirically informed framework of benefits in crowdfunding from this study fills a gap in crowdfunding research and provides the basis for new enquiries. This adds value by illustrating the potential of crowdfunding research to go beyond a concern with platform activity to a better understanding of the impact on small business development and entrepreneurial learning when deciding on funding sources. The paper highlights that the issues relating to crowdfunding go beyond simple access to project finance to seeing crowdfunding as one aspect of a broader resource development strategy for early-stage projects. Furthermore, it illustrates how the entrepreneurs’ own ambitions and approaches to venture development inform how they engage with crowdfunding investors. Finally, the framework suggests that the concept of democratic ‘crowd’ involvement may go beyond platform investment dynamics, through beginning to outline the process through which a new form of community stakeholder engagement in early-stage projects may be emerging. As a pilot study there is an opportunity to develop this study further by conducting international cross-case analysis to further refine and contextualise the benefits framework and extend through further exploring the issues identified