Carbon cage-like materials as potential low work function metallic compounds: Case of clathrates

We present an ab-initio calculation of the electronic affinity of the hypothetical C-46 clathrate by studying its bare and hydrogenated (100) surfaces. We show that such a system shares with the diamond phase a small electronic affinity. Further, contrary to the diamond phase, the possibility of doping endohedrally these cage-like systems allows to significantly raise the position of the Fermi level, resulting in a true metal with a small work function. This is illustrated in the case of the Li8@C-46 doped compound. Such a class of materials might be of much interest for the design of electron-emitting devices.Comment: 4 pages, 3 figures, RevTe

Probability distribution of the seismic damage cost over the life cycle of structures

In the life-cycle analysis, the total cost of damage caused by earthquakes is a significant but highly uncertain component. In the current literature, the seismic risk analysis is largely limited to the evaluation of the average cost of damage, which is not informative about the full extent of variability in the cost. The paper presents a systematic development of the stochastic modeling of seismic risk analysis problem and reformulates the damage cost analysis as a superposition of compound Poisson processes. An explicit analytical solution for the distribution of damage cost is derived in form of a recursive equation. The proposed approach extends the capability of the existing framework of seismic risk analysis, which can be used to optimize initial design and retrofitting of structures.Natural Science and Engineering Research CouncilUniversity Network of Excellence in Nuclear Engineerin

Mechanische onkruidbestrijding in de gewasrij

Mechanische onkruidbestrijding is nodig bij gebrek aan effectieve onkruidbestrijdingsmiddelen en problemen met resistente onkruiden en ter vermindering van milieuproblemen met herbiciden. In de biologische landbouw is de onkruidbeheersing een kostbaar knelpunt. In fijnzadige gewassen wordt gemiddeld 150 uur per hectare gewied met name in de gewasrij en bestaat het risico op mislukking en de noodzaak tot onderploegen van gewas. Precisielandbouwtechnieken bieden mogelijkheden om mechanische onkruidbestrijding verde

Energierijk: Deelproject algenteelt

In de loop van 2012 heeft ACCRES-Wageningen UR in samenwerking met het bedrijf Algae Food & Fuel algenproductiefaciliteiten gerealiseerd op het terrein van ACRRES in Lelystad. Deze faciliteiten bestaan uit algenvijvers en fotobioreactoren met LED-verlichting. Het unieke van deze testfaciliteiten is dat verschillende productieprocessen aan elkaar gekoppeld worden door reststromen uit het ene proces toe te passen in het andere proces. Dit gebeurt binnen het zogenaamde EnergieRijk project. Centraal staat een co-vergister met warmtekrachtkoppeling. Het digestaat dat na het vergistingsproces overblijft, kan worden gebruikt als meststof voor de algenteelt. De gasmotor waarin het biogas verbrand wordt om stroom te produceren levert warmte en CO2 die in de algenvijvers verbruikt worden

Risk assessment of alien species found in and around the oyster basins of Yerseke

On behalf of the Office of Research and Risk Assessments (BuRO) of the Netherlands Food and Consumer Product Safey Authority (NVWA), IMARES conducted a species inventory in the Oyster basins in Yerseke and the surrounding area in the Eastern Scheldt, known to be subject to shellfish related activities. This inventory that was performed in September/October 2013 revealed 21 macro invertebrate species that are regarded as alien species. Five of these are assumed not to be present in the Wadden Sea and one species was discovered there once very recently. For all six alien species an assessment was performed to define the potential risk that they will reach the Wadden Sea and affect the local native ecosystem, which is described in this report

Biomassa-afhankelijk doseren van gewasbeschermingsmiddelen

Recentelijk zijn enkele doorbraken gerealiseerd op het gebied van biomassa-afhankelijk doseren in open teelten. Het gaat hierbij om plaatsspecifieke dosering van bepaalde herbiciden en fungiciden op basis van de hoeveelheid bovengrondse biomassa onder de spuitdoppen. Om dit effectief te maken, zijn toegesneden sensoren, beslisregels en spuitapparatuur nodig. Plaatsspecifieke dosering van loofdodingsmiddelen in consumptieaardappelen is nu praktijkrijp middels MLHD-PHK (Minimum Lethal Herbicide Dose-Potato Haulm Killing) in combinatie met de N-sensor (stikstof-sensor), of SensiSpray. In de testfase werd een reductie van gemiddeld 50% in het gebruik van loofdodingsmiddel t.o.v. gangbare praktijk bereikt. In dit artikel wordt een overzicht gegeven van onderwerpen op het gebied van biomassa-afhankelijk doseren van gewasbeschermingsmiddelen waarbij de Plant Science Groep (PSG) van Wageningen UR trekker van de ontwikkeling is

Applying Stretch to Evoke Hyperreflexia in Spasticity Testing: Velocity vs. Acceleration

\ua9 Copyright \ua9 2021 Sloot, Weide, van der Krogt, Desloovere, Harlaar, Buizer and Bar-On. In neurological diseases, muscles often become hyper-resistant to stretch due to hyperreflexia, an exaggerated stretch reflex response that is considered to primarily depend on the muscle\u27s stretch velocity. However, there is still limited understanding of how different biomechanical triggers applied during clinical tests evoke these reflex responses. We examined the effect of imposing a rotation with increasing velocity vs. increasing acceleration on triceps surae muscle repsonse in children with spastic paresis (SP) and compared the responses to those measured in typically developing (TD) children. A motor-operated ankle manipulator was used to apply different bell-shaped movement profiles, with three levels of maximum velocity (70, 110, and 150\ub0/s) and three levels of maximum acceleration (500, 750, and 1,000\ub0/s2). For each profile and both groups, we evaluated the amount of evoked triceps surae muscle activation. In SP, we evaluated two additional characteristics: the intensity of the response (peak EMG burst) and the time from movement initiation to onset of the EMG burst. As expected, the amount of evoked muscle activation was larger in SP compared to TD (all muscles: p < 0.001) and only sensitive to biomechanical triggers in SP. Further investigation of the responses in SP showed that peak EMG bursts increased in profiles with higher peak velocity (lateral gastrocnemius: p = 0.04), which was emphasized by fair correlations with increased velocity at EMG burst onset (all muscles: r > 0.33–0.36, p ≤ 0.008), but showed no significant effect for acceleration. However, the EMG burst was evoked faster with higher peak acceleration (all muscles p < 0.001) whereas it was delayed in profiles with higher peak velocity (medial gastrocnemius and soleus: p < 0.006). We conclude that while exaggerated response intensity (peak EMG burst) seems linked to stretch velocity, higher accelerations seem to evoke faster responses (time to EMG burst onset) in triceps surae muscles in SP. Understanding and controlling for the distinct effects of different biological triggers, including velocity, acceleration but also length and force of the applied movement, will contribute to the development of more precise clinical measurement tools. This is especially important when aiming to understand the role of hyperreflexia during functional movements where the biomechanical inputs are multiple and changing