Bladvlekken in zomerbloemen 2 : vervolg op onderzoek 2007-2008

Bladvlekkenziekten veroorzaken regelmatig problemen in de teelten van verschillende soorten zomerbloemen. Bladvlekken kunnen door verschillende ziekteverwekkende schimmels worden veroorzaakt. Om een betrouwbaar en gericht advies te geven is het van belang om te weten welk organisme de bladvlekken veroorzaakt. In dit project zijn monsters met bladvlekken bij telers verzameld en is met behulp van de infectieproeven getracht de veroorzaker aan te wijzen

Bladvlekken zomerbloemen : meer veroorzakers, dus extra alert reageren

Bladvlekkenziekten veroorzaken regelmatig problemen in de teelten van verschillende soorten zomerbloemen. Bladvlekken kunnen door verschillende ziekteverwekkende schimmels worden veroorzaakt

Cladosporium én Botrytis belangrijkste oorzaken bladvlekken in pioenroos

De schimmels Cladosporium paeoniae en Botrytis spp. veroorzaken verschillende soorten bladvlekken in pioenroos. PPO zocht uit welke schimmels of bacteriën in de bladvlekken aanwezig waren. Met deze kennis is het mogelijk om bladvlekkenziekten gerichter aan te pakken

An Outlook on the Localisation and Structure-Function Relationships of R Proteins in Solanum

The co-evolution of plants and plant-pathogens shaped a multi-layered defence system in plants, in which Resistance proteins (R proteins) play a significant role. A fundamental understanding of the functioning of these R proteins and their position in the broader defence system of the plant is essential. Sub-project 3 of the BIOEXPLOIT programme studies how R proteins are activated upon effector recognition and how recognition is conveyed in resistance signalling pathways, using the solanaceous R proteins Rx1 (from S. tuberosum spp. andigena; conferring extreme resistance against Potato Virus X), I-2 (from S. lycopersicon; mediating resistance to Fusarium oxysporum) and Mi-1.2 (from S. lycopersicon; conferring resistance to Meloidogyne incognita) as model systems. The results obtained in this project will serve as a model for other R proteins and will be translated to potential applications or alternative strategies for disease resistance. These include the modification of the recognition specificity of R proteins with the aim to obtain broad spectrum resistance to major pathogens in potato

The effect of fault ride-through requirements on voltage dips and post-fault voltage recovery in a Dutch distribution network

In this paper the possibility to use Decentralized Generation (DG) units for voltage support in Distribution Networks during and after a Short Circuit (S/C) event is discussed. Two types of DG units will be examined, Combined Heat-Power (CHP) plants and Doubly-Fed Induction Generators (DFIG). Earlier approaches would oblige the disconnection of these units during grid disturbances, in order to avoid unwanted conditions such as interference with the protection system and islanding [1]. Newer grid codes for Transmission Networks like [2], taking into consideration the increased share of these units in energy production have set specific Fault Ride-Through (FRT) criteria which oblige them to stay connected during SC events when they are combined to large plants directly connected to the transmission grid, such as (off shore) wind farms.. If ever more DG is connected directly to distribution grids, the same reasoning leading to applying rault ride through criteria to DG connected in large groups to transmission grids, may be applied to DG connected to distribution grids, as a loss of a a large amount of DG connected to distribution grids has the same adverse effect as using DG connected directly to the transmission grid

Response of MV-connected Doubly-Fed Induction Generator wind turbines and CHP-plants to grid disturbances

Notwithstanding the positive environmental impact, the increasing penetration of Distributed Generation (DG) units connected to the distribution network raises new topics concerning the expected response of these during outages. Grid disturbances especially at the transmission level can cause the unwanted disconnection of large amounts of DG, leading to undesired power imbalances causing line overloadings and/or voltage and frequency instability. This paper examines how transmission network faults can affect the operation of DG units connected on to the distribution network, how these units currently contribute to the voltage support and what are the consequences of actual and possible Fault Ride-Through (FRT) behaviors

Stikstofbijmestsysteem voldoet aan N-behoefte lelie en gladiool

De aanleiding tot dit onderzoek was het van kracht worden van de N-gebruiksnormen voor landbouwgewassen in 2006 die volgens telers van lelie en gladiool en voorlichters te laag is voor een optimale teelt. In de belangrijkste teeltgebieden van lelie en gladiool, nl. de Noordoostpolder (NOP), Noordoost-Nederland (NON) en Zuidoost-Nederland (ZON) zou de N-behoefte van lelie en gladiool voor een optimaal teelt- en afbroeiresultaat hoger zijn dan de gebruiksnorm

Tensor Power Flow Formulations for Multidimensional Analyses in Distribution Systems

In this paper, we present two multidimensional power flow formulations based on a fixed-point iteration (FPI) algorithm to efficiently solve hundreds of thousands of power flows in distribution systems. The presented algorithms are the base for a new TensorPowerFlow (TPF) tool and shine for their simplicity, benefiting from multicore \gls{cpu} and \gls{gpu} parallelization. We also focus on the mathematical convergence properties of the algorithm, showing that its unique solution is at the practical operational point, which is the solution of high-voltage and low-current. The proof is validated using numerical simulations showing the robustness of the FPI algorithm compared to the classical \gls{nr} approach. In the case study, a benchmark with different PF solution methods is performed, showing that for applications requiring a yearly simulation at 1-minute resolution the computation time is decreased by a factor of 164, compared to the NR in its sparse formulation