Influence of surface energy anisotropy on nucleation and crystallographic texture of polycrystalline deposits

This paper aims to elucidate the role of interface energy anisotropy in orientation selection during nucleation of new grains in a polycrystalline film growth. An assessment of (heterogeneous) nucleation probability as function of orientation of both the bottom grain and of the nucleus was developed (using the concepts of classical nucleation theory). Novel solutions to the generalized Winterbottom construction were described in cases of very strong anisotropy and arbitrary orientations. In order to demonstrate the effect on the film crystallographic texture, a 2D Monte Carlo algorithm for anisotropic polycrystalline growth was used to simulate growth of films with columnar microstructure. The effect of strength of anisotropy, the deposition rate and initial texture were investigated. Results showed that with larger strength of anisotropy, the nucleation rate is less dependent on the driving force, but more dependent on the initial texture. With certain initial textures, the anisotropic nucleation may even be either impossible or having probability close to one irrespective of the driving force. Depending on the conditions, the anisotropic nucleation could hasten the evolution towards the interface-energy minimizing texture or retard it. Based on these insights, a hypothesis was offered to explain a peculiar texture evolution in electrodeposited nickel.Comment: 18 pages, 14 figures, 1 table Submitted in September 2023 to Computational Materials Science, Elsevie

Influence of rigid body motion on the attachment of metallic droplets to solid particles in liquid slags - a phase field study

Metallic droplets can remain attached to solid particles within liquid slags, resulting in production losses in several pyrometallurgical industries. This study shows the extension of a recently developed phase field model to include the movement of solid particles in the liquid slag in a system, considering the attachment of liquid metal droplets to solid particles in slags. The influence of this movement on the wetting of the metal droplets to the solid particles in the slag and on the resulting microstructures is investigated as a function of the velocity of the particles. For all wetting regimes, the apparent contact angle in the final microstructures was clearly larger than without particle movement. For the amount of metal attached to the particle, a clear trade-off was found between the speed of motion of the solid particle and the wetting regime

Grain Growth in Thin Films with a Fibre Texture Studied by Phase-Field Simulations and Mean Field Modelling

The evolution of fiber textured structures is simulated in 2 dimensions using a generalized phase field model assuming two forms for the misorientation, a steady-state regime is reached after a finite amount of grain growth, where the numer and length weighted misorientation distribution functions (MDF) are constant in time, and the mean grain area A as a function of time t follows a power growth law A - A0 = kt^n with n close to 1 and A0 the initial mean grain area. The final shape of the MDF and value of the prefactor k in the power growth law clearly correlate with the misorientation dependence of the grain boundary energy. From a quantitative point of view, the fraction of special boundaries obtained in simulations is quite sensitive to the number of possible discrete orientations. Furthermore, a mean field approach is worked out to predict the growth exponent for systems with nonuniform grain boundary energy. The conclusions from the mean field approach are consistent with the simulation results.Physic

Privacy Preserving ID3 over Horizontally, Vertically and Grid Partitioned Data

We consider privacy preserving decision tree induction via ID3 in the case where the training data is horizontally or vertically distributed. Furthermore, we consider the same problem in the case where the data is both horizontally and vertically distributed, a situation we refer to as grid partitioned data. We give an algorithm for privacy preserving ID3 over horizontally partitioned data involving more than two parties. For grid partitioned data, we discuss two different evaluation methods for preserving privacy ID3, namely, first merging horizontally and developing vertically or first merging vertically and next developing horizontally. Next to introducing privacy preserving data mining over grid-partitioned data, the main contribution of this paper is that we show, by means of a complexity analysis that the former evaluation method is the more efficient.Comment: 25 page

ESR1 amplification is rare in breast cancer and is associated with high grade and high proliferation: a multiplex ligation-dependent probe amplification study

Background: Expression of estrogen receptor alpha (ERα) is predictive for endocrine therapy response and an important prognostic factor in breast cancer. Overexpression of ERα can be caused by estrogen receptor 1 (ESR1) gene amplification and was originally reported to be a frequent event associated with a significantly longer survival for ER-positive women treated with adjuvant tamoxifen monotherapy, which was however questioned by subsequent studies

Metal droplet entrainment by solid particles in slags : an experimental approach

This study investigates the origin of the attachment of metal droplets to solid spinel particles in liquid slags. Previous research hinted a reactive origin: the spinel particles form by a chemical reaction together with a new droplet or alongside a droplet that was already present in the system. In this study, a smelting experiment was used to investigate this hypothesis. For such a study of the mechanism, a simple chemical system was used to avoid complex reactions. However, performing smelting experiments in simple slag systems requires an adaptation of the previously developed experimental methodology, resulting in a new 'partial melting' methodology. During the experiment, the atmosphere of the system was first set as oxidative, to dissolve the metallic copper in the slag and then a reductive atmosphere was used to actuate the reaction. Moreover, Ag was added to the metallic phase to act as a tracer element. The results show that the amount and size of copper droplets increase over the duration of the experiment. The fact that silver is present in the attached copper droplets in a smaller concentration than in the master alloy in this study indicates that the origin of the attachment is not purely dispersive, and either a purely reactive or a dispersion-reaction combination is possible, which confirms the hypothesis