Nematodes as suitable indicators for soil health

During the Greenresilient project, nematode communities will be characterized at the beginning, in the middle and at the end of the field trials to identify shifts in their community. These shifts will be analysed to determine whether the chosen ‘innovative’ methods tested in the project are beneficial for soil health, causing an increased resilience to pests and diseases and a more balanced nutrient supply, for more sustainable and high-quality crop production. This leaflet explains why nematodes can be excellent indicators for soil health

Cycloidal versus skyrmionic states in mesoscopic chiral magnets

When subjected to the interfacially induced Dzyaloshinskii-Moriya interaction, the ground state in thin ferromagnetic films with high perpendicular anisotropy is cycloidal. The period of this cycloidal state depends on the strength of the Dzyaloshinskii-Moriya interaction. In this work, we have studied the effect of confinement on the magnetic ground state and excited states, and we determined the phase diagram of thin strips and thin square platelets by means of micromagnetic calculations. We show that multiple cycloidal states with different periods can be stable in laterally confined films, where the period of the cycloids does not depend solely on the Dzyaloshinskii-Moriya interaction strength but also on the dimensions of the film. The more complex states comprising skyrmions are also found to be stable, though with higher energy.Comment: 8 pages, 10 figure

Micromagnetic modelling of anisotropic damping in ferromagnet

We report a numerical implementation of the Landau-Lifshitz-Baryakhtar theory, which dictates that the micromagnetic relaxation term obeys the symmetry of the magnetic crystal, i. e. replacing the single intrinsic damping constant with a tensor of corresponding symmetry. The effect of anisotropic relaxation is studied in thin saturated ferromagnetic disk and ellipse with and without uniaxial magneto-crystalline anisotropy. We investigate the angular dependency of the linewidth of magnonic resonances with respect to the given structure of the relaxation tensor. The simulations suggest that the anisotropy of the magnonic linewidth is determined by only two factors: the projection of the relaxation tensor onto the plane of precession and the ellipticity of the later.Comment: 6 pages, 5 figures, submitted to PRB Rapid. Com

Modelling compensated antiferromagnetic interfaces with MuMax3

We show how compensated antiferromagnetic spins can be implemented in the micromagnetic simulation program MuMax3. We demonstrate that we can model spin flop coupling as a uniaxial anisotropy for small canting angles and how we can take into account the exact energy terms for strong coupling between a ferromagnet and compensated antiferromagnet. We also investigate the training effect in biaxial antiferromagnets and reproduce the training effect in a polycrystalline IrMn/CoFe bilayer.Comment: 11 pages + Supplementary Material (10 pages

Effects of spatially engineered Dzyaloshinskii-Moriya interaction in ferromagnetic films

The Dzyaloshinskii-Moriya interaction (DMI) is a chiral interaction that favors formation of domain walls. Recent experiments and ab initio calculations show that there are multiple ways to modify the strength of the interfacially induced DMI in thin ferromagnetic films with perpendicular magnetic anisotropy. In this paper we reveal theoretically the effects of spatially varied DMI on the magnetic state in thin films. In such heterochiral 2D structures we report several emergent phenomena, ranging from the equilibrium spin canting at the interface between regions with different DMI, over particularly strong confinement of domain walls and skyrmions within high-DMI tracks, to advanced applications such as domain tailoring nearly at will, design of magnonic waveguides, and much improved skyrmion racetrack memory

Simulation and Analysis of the Operation and Reconfiguration of a Medium Voltage Distribution Network in a Smart Grid Context in MATLAB Simulink

This work will present a Medium Voltage Distribution Network that is operated as a Smart Grid. As the distribution infrastructure for electric energy ages and the share of EV’s and renewables increases, changes will have to be made to support the increasing power flows in the network. A more long-term solution than reinforcing the network with heavier cables is constructing an intelligent network that reacts to changing power flows inside the network and adapts accordingly to guarantee optimal functionality. External data from an optimisation algorithm is used to determine the switching behaviour. The network was modeled and analysed using a simulation software. If done correctly, a simulation can offer a lot of insight for only a fraction of the cost of constructing and testing the network in reality. MATLAB Simulink was used for the virtual modeling and analysis of the network. The main objective is to construct a model of the MVDN and use it to generate and analyse the power flows in the network to determine the plausibility of exploiting a similar network in an existing city. The models for each of the network components were developed and picked to combine them into a functioning network model based on the smart city’s topology. Simulating a smart grid is in essence not novel, but has not been done in Simulink before in this context. The hardest obstacle to overcome during the construction of the network model was finding a way to achieve the making and breaking of network connections in a way that Simulink could compute the network parameters correctly and in a timely manner. A whole section is dedicated to resolving these development issues. Following this, the results of the simulation regarding power flows and losses in the network are discussed. When it comes to the renewable generation implementation, the results showed promising results, even on days with low wind velocity the renewables aided in reducing the power demanded from the substation. The total generated power is compared with the total consumed power in the loads to find the grid losses. It became apparent very quickly that the grid losses were very high, up to 9.7%, which is a lot higher than the expected 2-6%. Overall the model showed promising results, as well as serving as a baseline for future works to improve upon

Stress in wild and captive snakes : quantification, effects and the importance of management

As in other animals, distress and impaired welfare have a deleterious effect on the mental, physical and behavioral health of snakes in the wild and in captivity. Besides anthropogenic disturbance, the availability of food and shelter, the presence of predators, and environmental factors, such as seasonality and climatological changes, are important factors that affect the stress level and subsequent welfare in wild snake populations. In captive snakes, inappropriate management is the most prominent cause of chronic stress and impaired welfare. Chronic stress can be assumed by looking at the snake's behavior, but there is need for a standardized quantification method to pin-point more accurately (chronic) stress levels. The biomarker suitable in this framework is the level of corticosterone in plasma, feces and shed skin

Crisis? What crisis? The World Bank and Housing Finance for the Poor. SOAS Department of Economics Working Paper Series, No. 191.

This paper provides a critical assessment of the Bank’s housing policies, against the backdrop of far-reaching transformations of the financial sector across the world and a persistently dire shelter situation in developing countries. It situates the Bank’s housing stance historically since its initial involvement in the sector in the early 1970s. This allows to shed light on systemic and analytical tendencies bearing on Bank housing policy with significant implications for the Bank’s current policy stance, including its response (or lack thereof) to the dramatic experience with housing finance laid bare through the global financial and economic crisis