Tetragonal zirconia: Wet chemical preparation, mechanical and electrical properties

Yttria-stabilized zirconia powders were prepared in the composition range of 3 to 13 at% yttria. The hydrolysis-gel precipitation technique was used, starting from metal alkoxides or chlorides. In the composition range between 5 and 10 at% yttria, the materials sintered at 1250°C have a fully tetragonal structure. The density was higher than 95% and the grain sizes can be varied between 0.1 and 0.5μm depending on the preparation conditions. The fracture toughness KIC amounts 6 to 11 MPam but is not dependent on the composition. The transformation toughening mechanism and the properties of the tetragonal phase itself play an important role in the increase of KIC compared with cubic materials. The magnitude of the oxygen-ion conductivity value is comparable with that for cubic materials

Dense Regular Packings of Irregular Non-Convex Particles

We present a new numerical scheme to study systems of non-convex, irregular, and punctured particles in an efficient manner. We employ this method to analyze regular packings of odd-shaped bodies, not only from a nanoparticle but also both from a computational geometry perspective. Besides determining close-packed structures for many shapes, we also discover a new denser configuration for Truncated Tetrahedra. Moreover, we consider recently synthesized nanoparticles and colloids, where we focus on the excluded volume interactions, to show the applicability of our method in the investigation of their crystal structures and phase behavior. Extensions to the presented scheme include the incorporation of soft particle-particle interactions, the study of quasicrystalline systems, and random packings.Comment: 4 pages, 3 figure

Een historische uitspraak over gaswinning?

Afdeling bestuursrechtspraak van de Raad van State 15 november 2017, ECLI: NL: RVS: 2017: 315

Building or stumbling blocks? Assessing the performance of polycentric energy and climate governance networks

Polycentric governance networks are on the rise in global energy and climate governance, but we know surprisingly little about their effectiveness. This paper analyzes the performance of four such transnational energy and climate governance networks. In the realm of sustainable energy, our cases are the Renewable Energy and Energy Efficiency Partnership (REEEP) and the Global Alliance for Clean Cookstoves (GACC). In the climate sphere, we examine the effectiveness of the Green Climate Fund (GCF) and the Clinton Climate Initiative (CCI). Using principles from governance and public administration about the effectiveness of institutions, we examine the extent to which four networks have contributed to improving governance outcomes in the spheres of climate and sustainable energy. Our evaluation focuses on the clarity of purpose, funding, institutional formality, efficacy,  and level of resilience of these networks. Some differences between the networks notwithstanding, we find that the transnational governance networks generally fail to meet the criteria about what constitutes an effective institution.  The paper concludes with a reflection on what could be done to enhance the performance of these governance networks

Introduction: Company Tax Integration in the European Union – A Necessary Step to Neutralise ‘Excessive’ Behaviour within the EU?

__Abstract__ This special issue of the Erasmus Law Review is the result of an interdisciplinary workshop on ‘Company Tax Integration in the European Union – a Necessary Step to Neutralise “Excessive” Behaviour within the EU?’, held at the Erasmus School of Law in June 2013 and organized by the Foundation European Fiscal Studies in co-operation with Erasmus Law Review. A topic currently attracting considerable public attention, not least because of the Base Erosion and Profit Shifting (BEPS) project of the OECD instigated by the G20. During the past decades there has been intensive tax competition between EU Member States for attracting capital triggered inter alia by the four freedoms as laid down in the European treaties. Even though competition is widely seen as beneficial to society, in case of inter-jurisdictional tax competition this may not always be the case. The possible negative effects of inter-jurisdictional tax competition and aggressive tax planning by multinational companies on state’s tax revenue may lead to a shift of the tax burden onto less mobile activities and onto consumption in order to keep a state’s public finances stable. In the end a jurisdiction’s tax system may become distorted (inefficient) and distribution unfair. In order to neutralize the negative effects of harmful tax competition and aggressive tax planning, one might be of the opinion that integrating company taxes within the EU would be the only way forward

A Triangular Tessellation Scheme for the Adsorption Free Energy at the Liquid-Liquid Interface: Towards Non-Convex Patterned Colloids

We introduce a new numerical technique, namely triangular tessellation, to calculate the free energy associated with the adsorption of a colloidal particle at a flat interface. The theory and numerical scheme presented here are sufficiently general to handle non-convex patchy colloids with arbitrary surface patterns characterized by a wetting angle, e.g., amphiphilicity. We ignore interfacial deformation due to capillary, electrostatic, or gravitational forces, but the method can be extended to take such effects into account. It is verified that the numerical method presented is accurate and sufficiently stable to be applied to more general situations than presented in this paper. The merits of the tessellation method prove to outweigh those of traditionally used semi-analytic approaches, especially when it comes to generality and applicability.Comment: 21 pages, 11 figures, 0 table

Caudal cervical vertebral morphological variation is not associated with clinical signs in Warmblood horses

Background Variation in equine caudal cervical spine morphology at C6 and C7 has high prevalence in Warmblood horses and is suspected to be associated with pain in a large mixed-breed group of horses. At present no data exist on the relationship between radiographic phenotype and clinical presentation in Warmblood horses in a case-control study. Objectives To establish the frequency of radiographically visible morphologic variation in a large group of Warmblood horses with clinical signs and compare this with a group without clinical signs. We hypothesised that occurrence of morphologic variation in the case group would not differ from the control group, indicating there is no association between clinical signs and morphologic variation. Study design Retrospective case-control. Methods Radiographic presence or absence of morphologic variation of cervical vertebrae C6 and C7 was recorded in case (n = 245) and control horses (n = 132). Case and control groups were compared by univariable Pearson's Chi-square and multivariable logistic regression for measurement variables age, sex, breed, degenerative joint disease and morphologic variation at C6 and C7. Odds ratio and confidence intervals were obtained. A P <= 0.05 was considered statistically significant. Results Morphologic variation at C6 and C7 (n = 108/377 = 28.6%; Cases 58/245 = 23.7%; Control 50/132 = 38%) was less frequent in horses with clinical signs in univariable testing (OR 0.48, 95% CI 0.3-0.8, P = 0.001). Age, sex, breed and degenerative joint disease were not retained in the final multivariable logistic regression step whereas morphologic variation remained significantly less present in horses with clinical signs. Main limitations Possible demographic differences between equine clinics. Conclusions Morphologic variation in the caudal cervical spine was detected more frequently in horses without clinical signs. Therefore, radiographic presence of such variation does not necessarily implicate the presence of clinical signs